DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Amendment
Claims 5,7,15,17,20-23,25-26 and 29-35 are pending. Claims 7, 15, 17, 23, 25 are amended. Claims 29-35 are new.
Claim Interpretation
The following is a quotation of 35 U.S.C. 112(f):
(f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The following is a quotation of pre-AIA 35 U.S.C. 112, sixth paragraph:
An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
This application includes one or more claim limitations that do not use the word “means,” but are nonetheless being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, because the claim limitation(s) uses a generic placeholder that is coupled with functional language without reciting sufficient structure to perform the recited function and the generic placeholder is not preceded by a structural modifier.
Such claim limitation(s) is/are: “surface measurement apparatus” in claim 25, 22. These limitations are interpreted to be surface measurement apparatus 120, which is configured to provide optical, electrical, thermal, pressure, and/or acoustical sensing.
Because this/these claim limitation(s) is/are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, it/they is/are being interpreted to cover the corresponding structure described in the specification as performing the claimed function, and equivalents thereof.
If applicant does not intend to have this/these limitation(s) interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, applicant may: (1) amend the claim limitation(s) to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph (e.g., by reciting sufficient structure to perform the claimed function); or (2) present a sufficient showing that the claim limitation(s) recite(s) sufficient structure to perform the claimed function so as to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 29, 32 rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
With respect to claims 29 and 32, the claim limitation “wherein a ratio of an annular width of a peripheral pressure element directly adjacent to the second innermost pressure element and an annular width of an overlap region defined between the outer sidewall of the second innermost pressure element and the inner sidewall of the peripheral pressure element is greater than or equal to approximately 3:1”. In particular, the specification does not provide for any specific ratio in terms of dimensions of the overlap region (and does not specify any overlap region). While an overlap itself can be found in instant fig. 3, and is understood to be present when there the pressure elements of the various CMP heads are compared to each other, it has been previously held that drawings are not to scale, and do not demonstrate proportions, unless otherwise indicated that the drawings are to scale (see MPEP 2125). While the examiner acknowledges that the standard for written description and anticipation are different, the examiner submits that the instant disclosure can not be deemed to support the claimed limitation, if a published patent application containing the content of instant disclosure, cannot be deemed to anticipate the claimed limitation, as the drawings would not have been to scale.
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 29, 32 rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
The term “approximately 3:1” in claims 29, 32 is a relative term which renders the claim indefinite. The term “approximately” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. As noted in the 112(a) rejection of claims 29 and 32 above, the limitation lacks description in the specification, and because the drawings are not to scale, the specific bounds of what “approximately 3:1” can not be determined.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim(s) 5, 7, 15, 25, 26, 29 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yoshida (US Pub. 20150311097 A1) in view of Zhang-‘897 (US Pub. 20120277897 A1).
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Ann. Fig 6 (Yoshida)
(Examiner notes that claim 25 is addressed first in this grouped rejection, as the rest of the claims under this rejection header depend on claim 25)
With respect to claim 25, Yoshida discloses: A chemical mechanical polishing (CMP) system comprising:
a first CMP head configured to retain a workpiece, (31C, fig. 1 analogous to 31a which holds a wafer, described in [0081-0082]), the first CMP head comprising a first plurality of pressure elements that are concentric about a central axis of the first CMP head and disposed across a first pressure control plate (pressure control plate analogous to instant disclosure shown in ann. fig. 6; the arrangements shown in fig. 9, C1-C4 being pressure elements; explained in [0123]; [0106, 0112] provide for the pressure elements to be concentrically arranged, with annular/circular elements, which are placed around a central axis); a first innermost pressure element of the first plurality of pressure elements having a first outer diameter defined by an outer sidewall of the first innermost pressure element (since the pressure elements are concentric/annular, they have a sidewall at the perimeter, of each element), and peripheral pressure elements of the first plurality of pressure elements having respective annular thicknesses defined between respective inner and outer sidewalls of the respective peripheral pressure elements of the first plurality of pressure elements (all pressure elements have annular thicknesses defined by the sidewalls, shown as 403a, in fig. 6, and the pressure elements shown in fig. 9 are also delineated by sidewalls); and
a second CMP head configured to retain the workpiece (31D, fig. 1 analogous to 31a which holds a wafer, described in [0081-0082]), the second CMP head comprising a second plurality of pressure elements that are concentric about a central axis of the second CMP head and disposed across a second pressure control plate (the arrangements shown in fig. 9, D1-D4 being pressure elements; explained in [0123], [0106, 0112] provide for the pressure elements to be concentrically arranged, with annular/circular element, which are placed around a central axis), the second plurality of pressure elements and the first plurality of pressure elements having the same number of pressure elements as one another (the number of pressure elements can be the same, in this case there are 4 pressure elements, however it is noted that there is no particular limitation on the number of pressure chambers in each of the two heads as long as there is at least two ([0112,0116]), a second innermost pressure element of the second plurality of pressure elements having a second outer diameter defined by an outer sidewall of the second innermost pressure element of the second plurality of pressure elements (since the pressure elements are concentric/annular, they have a sidewall at the perimeter, of each element), and peripheral pressure elements of the second plurality of pressure elements having respective annular thicknesses defined between respective inner and outer sidewalls of the respective peripheral pressure elements of the second plurality of pressure elements (all pressure elements have annular thicknesses defined by the sidewalls, shown as 403a, in fig. 6, and the pressure elements shown in fig. 9 are also delineated by sidewalls); and
wherein the first CMP head is configured to have a first removal profile on the first surface of the workpiece and the second CMP head is configured to have a second removal profile on the first surface (both CMP heads have different removal profiles, see fig. 8A, 8B, [0121, 0122]), wherein the CMP system is configured to have a combined removal profile on the first surface based on the first removal profile and the second removal profile (this functional effect would occur when polishing is done on one CMP head and subsequent polishing is done on a second, see [0122]),
wherein the first removal profile has minimum removal rates at inner and outer sidewalls of a peripheral pressure element of the first pressure control plate and has a maximum removal rate at a diameter corresponding to a midpoint between the inner and outer sidewalls of the peripheral pressure element of the first pressure control plate (see fig. 8A, 8B, [0121, 0122]; see also [0008], which also describes, in addition to [0122] how at the boundary of the pressure elements/chambers there is a low removal rate) and the second removal profile of the second CMP head has a maximum removal rate at a diameter that is radially offset from the inner and outer sidewalls of the peripheral pressure element of the first pressure control plate (because the boundaries of the second CMP head pressure elements are offset radially from the inner/outer sidewalls of the first CMP head, as in fig. 9, see comparison between C1-C4, and D1-D4, the effect would be as claimed),
a third CMP head configured to retain the workpiece, (Yoshida, 31b, fig. 1, analogous to 31a which holds a wafer, described in [0081-0082]),
Yoshida does not explicitly disclose
wherein the second outer diameter of the second innermost pressure element in the second plurality of pressure elements is greater than the first outer diameter of the first innermost pressure element in the first plurality of pressure elements, wherein when a line normal to upper surfaces of the first and second CMP heads passes through the central axis of a first CMP head CMP head and passes through the central axis of the second CMP head, the outer sidewalls of the peripheral pressure elements, respectively, in the first plurality of pressure elements correspond to a first plurality of outer diameters, respectively, and the outer sidewalls of the peripheral pressure elements, respectively, in the second plurality of pressure elements correspond to a second plurality of outer diameters, respectively, wherein the second plurality of outer diameters, respectively, are larger than the first plurality of outer diameters, respectively, to define a plurality of overlap regions, respectively, the overlap regions having respective annular widths, wherein the combined removal profile exhibits minimum removal rates at respective midpoints of the respective annular widths of the respective overlap regions; and a surface measurement apparatus configured to measure a planarity of a first surface of the workpiece, and
wherein the third CMP head comprises a third plurality of pressure elements that are concentric about a central axis of the third CMP head and are disposed across a third pressure control plate, the third plurality of pressure elements and the first plurality of pressure elements having different numbers of pressure elements from one another, wherein a third innermost pressure element of the third plurality of pressure elements has a third outer diameter defined by an outer sidewall of the third innermost pressure element of the third plurality of pressure elements, and peripheral pressure elements of the third plurality of pressure elements having respective annular thicknesses are defined between respective inner and outer sidewalls of the respective peripheral pressure elements of the third plurality of pressure elements, wherein the third outer diameter of the third innermost pressure element in the third plurality of pressure elements is greater than the first outer diameter of the first innermost pressure element in the first plurality of pressure elements and is greater than the second outer diameter of the second innermost pressure element in the second plurality of pressure elements, and wherein a maximum annular width for the first plurality of pressure elements is less than a minimum annular width for the third plurality of pressure elements.
However, Yoshida does disclose that the two arrangements of pressure elements in the first and second CMP head are different and that in doing so one can reduce the number of pressure elements in a single CMP head while achieving the same CMP effect – achieving precise profile control ([0124]), and that different CMP heads have different costs ([0024]). As noted above, Yoshida also discloses that there is no particular limitation on the number of pressure chambers in each of the two heads as long as there is at least two ([0112,0116]).
Furthermore, as previously noted, Yoshida also describes a polishing step using pressure chambers C1-C4 would result in a lower polishing rate at the boundaries of the pressure chambers in [0122].
Yoshida further teaches an arrangement of where the outermost pressure elements of the second plurality of pressure elements are arranged to have a narrow width (fig. 10, [0055], referring to an arrangement of D1-D4, specifically D2-D4), and explains that such an arrangement is to provide fine/precise at a peripheral portion of an wafer ([0055,0125]), and also teaches of a narrow width of an innermost set of pressure elements (fig. 12, [0057], referring to an arrangement of D1-D4, specifically D1-D3), and teaches that this provides for fine/precise control at a central portion of a wafer ([0057,0125]).
MPEP 2144.05 II provides that routine optimization of a result effective variable within prior art conditions, would have been obvious to a person of ordinary skill in the art and MPEP 2144.04 IV provides that changes in size/proportion would have been obvious to a person of ordinary skill in the art.
It would have been obvious for one of ordinary skill in the art, before the effective filing date of the claimed invention to have made a pressure element distribution wherein the second outer diameter of the second innermost pressure element in the second plurality of pressure elements is greater than the first outer diameter of the first innermost pressure element in the first plurality of pressure elements, wherein when a line normal to upper surfaces of the first and second CMP heads passes through the central axis of a first CMP head CMP head and passes through the central axis of the second CMP head, the outer sidewalls of the peripheral pressure elements, respectively, in the first plurality of pressure elements correspond to a first plurality of outer diameters, respectively, and the outer sidewalls of the peripheral pressure elements, respectively, in the second plurality of pressure elements correspond to a second plurality of outer diameters, respectively, wherein the second plurality of outer diameters, respectively, are larger than the first plurality of outer diameters, respectively, to define a plurality of overlap regions, respectively, the overlap regions having respective annular widths, wherein the combined removal profile exhibits minimum removal rates at respective midpoints of the respective annular widths of the respective overlap regions, as a optimization of a result effective variable (size/placement of pressure elements) or a change in size/proposition for the reasons given above of selecting an appropriate placement of pressure element boundaries for fine polishing at specific areas, which would result in the claimed limitations, as the claimed arrangement is obtained by varying the position of the pressure element boundaries to obtain different pressure element widths, to result in the claimed arrangement where the arrangement of the first and second CMP heads are defined with respect to their annular diameter and size of an overlap when the arrangement is compared in a stacked vertical arrangement. A person of ordinary skill in the art would have made the modification with a reasonable expectation of success.
The claimed limitations of “wherein the combined removal profile exhibits minimum removal rates at respective midpoints of the respective annular widths of the respective overlap regions” depend on the arrangement of the pressure elements and, in view of Yoshida above, are obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, given that one would select the boundaries (to result in different widths and overlap regions) of the pressure elements for the reasons given by Yoshida, which would functionally cause the claimed effect given the previous explanation of how the polishing rate is reduced at the boundaries of the pressure elements.
As for the limitations regarding a surface measurement apparatus, Zhang-‘897, in the same field of endeavor teaches of a CMP system with:
a surface measurement apparatus (160, fig. 1, of the optical type, measuring surface profile (planarity) as in [0042], so is a 112f equiv. measuring surface profile) positioned on a platen (120, fig. 1)
wherein the surface measurement apparatus is configured to measure a planarity of the surface of the workpiece (measure in-situ during polishing in [0036]; in-situ monitoring system described as measuring a surface profile (planarity) in [0042]; metrology station also described in [0056]). Zhang-‘867 also teaches of measuring while polishing in [0036]) while performing a first CMP process and wherein pressures exerted by a plurality of concentric pressure elements during second CMP process are independently varied ([0072] – teaches of a combination of suitable chamber pressures; fig. 1 shows pressure chambers 146a, 146b, 146c; which are independently controlled [0008]) based ([0009] –“wherein the target removal profile may be generated from data collected in-situ during polishing of a first substrate at a first platen, and polishing the first substrate at a different second platen using the chamber pressure”) on the measured planarity of the to-be-polished surface after the first CMP process.
Zhang-‘897 teaches that this helps compensate for any non-uniformity in the processing process ([0005]).
It would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to have incorporated the surface measurement apparatus of Zhang-‘897 into the system of Yoshida, for the reasons described above, and have adjusted the controlled a second CMP process using measurements from the surface measurement apparatus, for the reasons described above.
As for the specifics regarding the third CMP head, Yoshida, as noted above, teaches that the two arrangements of pressure elements in the first and second CMP head are different and that in doing so one can reduce the number of pressure elements in a single CMP head while achieving the same CMP effect – achieving precise profile control (Yoshida, [0124]), and that different CMP heads have different costs (Yoshida, [0024]). Yoshida also discloses that there is no particular limitation on the number of pressure chambers in each of the two heads as long as there is at least two (Yoshida, [0112,0116]) and that the configuration of the CMP heads may be arbitrary changed (Yoshida, [0126]), and that using pressure chambers C1-C4 would result in a lower polishing rate at the boundaries of the pressure chambers in [0122], thus demonstrating the need to polish wafers with an arrangement that is different, and that there is no particular limitation on the number of pressure chambers in each of the two heads as long as there is at least two (Yoshida, [0112,0116]), and that multi-zone pressure heads can be costly, and that there is a limit to the number of pressure zones/chambers, but more pressure zones/elements provide for more control (Yoshida, [0006-0008]).
Yoshida also teaches that the polishing heads may be arranged in any way (Yoshida, [0126]). As an example, in Yoshida, Example 5 of Fig. 14 and described in [0129] for when only use of multi-pressure zone/element polishing heads (“exemplary selection of polishing heads in a case of a small amount of polishing of a wafer, a high demand for planarization of a wafer surface, and a low demand for no defect”). As another example, in Yoshida, [0130-0131], Yoshida discloses of an arrangement where there are four CMP heads, with two having one structure and two having another structure defined by the membrane 403 (Yoshida, in fig. 6 the membrane 403 comprises partitions 403a that form the different pressure chambers D1-D4 as described in [0111-0112]).
MPEP 2144.05 II provides that routine optimization of a result effective variable within prior art conditions, would have been obvious to a person of ordinary skill in the art, MPEP 2144.04 IV provides that changes in size/proportion would have been obvious to a person of ordinary skill in the art, and MPEP 2144.04 VI provides that mere duplication of parts has no patentable significance unless a new and unexpected result is produced.
It would have been obvious for a person of ordinary skill in the art, before the effective filing date of the claimed invention to have provided for an additional polishing head (third CMP head) with multiple pressure elements, and to have arranged those pressure elements differently as a optimization of a result effective variable (size/placement of pressure elements), or a change in size/proportion for the reasons given above. It would have also been obvious for a person of ordinary skill in the art, before the effective filing date of the claimed invention to have provided a third polishing head with multiple pressure chambers as a duplication of one of the existing polishing heads with multiple pressure chambers, as a mere duplication of parts. A person of ordinary skill in the art would have made the modification with a reasonable expectation of success. The result would have been the third CMP head comprises a third plurality of pressure elements that are concentric about a central axis of the third CMP head and are disposed across a third pressure control plate, the third plurality of pressure elements and the first plurality of pressure elements having different numbers of pressure elements from one another, wherein a third innermost pressure element of the third plurality of pressure elements has a third outer diameter defined by an outer sidewall of the third innermost pressure element of the third plurality of pressure elements, and peripheral pressure elements of the third plurality of pressure elements having respective annular thicknesses are defined between respective inner and outer sidewalls of the respective peripheral pressure elements of the third plurality of pressure elements, wherein the third outer diameter of the third innermost pressure element in the third plurality of pressure elements is greater than the first outer diameter of the first innermost pressure element in the first plurality of pressure elements and is greater than the second outer diameter of the second innermost pressure element in the second plurality of pressure elements, and wherein a maximum annular width for the first plurality of pressure elements is less than a minimum annular width for the third plurality of pressure elements, this arrangement is an result that is obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, for the same reason that is provided with regards to the different between the arrangement pressure elements of the first and second CMP previously explained (in that Yoshida already provides the reasoning for varying the arrangement of the pressure elements, and the claim simply defines how the pressure elements are different in relative size and placement compared to another pressure element arrangement in a different CMP head).
With respect to claim 5, Yoshida, as modified, teaches the limitations of claim 25 above however does not explicitly teach wherein a maximum removal rate of the combined removal profile is configured to be less than a maximum removal rate of the first removal profile. However, the effect of the combined removal rate depends on the arrangement of the pressure elements and, in view of Yoshida, as applied in claim 25, is obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, given that one would select the appropriate boundaries of the pressure elements for the reasons given by Yoshida (i.e. the effect of reduced removal at a pressure element boundary, an arrangement can be selected to have destructive interference of the removal rate; such to generate more uniform (average) material removal over the entire process and given that the pressure elements of Yoshida otherwise structurally meet the claim limitation, they would function in an analogous manner; examiner notes that the polishing head does not deposit/add material to the wafer).
With respect to claim 7, Yoshida, as modified, teaches the limitations of claim 25, above and further teaches locations of the localized minimum removal rate spreads are based on a difference between distributions of the first plurality of pressure elements and the second plurality of pressure elements and an adjustment of pressures exerted by the second plurality of pressure elements based on the measured planarity of the first surface of the workpiece (as using Yoshida in the rejection of claim 25, the distribution/boundaries of the pressure elements has an effect on the removal rate, and as explained using Zhang-‘897 in claim 25, the polishing profile depends on the pressures excreted by the second plurality of pressure elements based on the measured planarity of the first surface of the workpiece).
With respect to claim 15, Yoshida, as modified, teaches the limitations of claim 25 above, and further teaches: a fourth polishing apparatus (Yoshida, 3A, fig. 1) comprising a fourth platen (Yoshida, 10, fig. 1) and a fourth CMP head (Yoshida, 31a, fig. 1), wherein the fourth CMP head is configured to perform a fourth CMP process on the first surface of the workpiece (Yoshida, [0081] explains the function of 31a),
however, does not explicitly teach wherein the fourth CMP head comprises a fourth plurality of concentric pressure elements and a fourth annular ring laterally enclosing the fourth plurality of concentric pressure elements, wherein widths of the fourth plurality of concentric pressure elements are respectively different from widths of the first, second, and third plurality of concentric pressure elements.
However, Yoshida, as modified, as already noted in the rejection of claim 25, does teach of two polishing apparatuses (the first and second polishing apparatuses, described in the rejection of claim 25 above) with analogous structure (the plurality of concentric elements and an annular ring enclosing the plurality of concentric pressure elements as previously described in the rejection of claim 25 above), that the two arrangements of pressure elements in the first and second CMP head are different and that in doing so one can reduce the number of pressure elements in a single CMP head while achieving the same CMP effect – achieving precise profile control (Yoshida, [0124]), and that different CMP heads have different costs (Yoshida, [0024]), as previously explained in the rejection of claim 25 above.
Additionally, Yoshida, as modified, as already noted in the rejection of claim 25, further teaches that the polishing heads may be arranged in any way (Yoshida, [0126]). As an example, in Example 5 of Fig. 14 and described in [0129] for when only use of multi-pressure zone/element polishing heads (“exemplary selection of polishing heads in a case of a small amount of polishing of a wafer, a high demand for planarization of a wafer surface, and a low demand for no defect”). As another example, in Yoshida, [0130-0131], Yoshida discloses of an arrangement where there are four CMP heads, with two having one structure and two having another structure defined by the membrane 403 (Yoshida, in fig. 6 the membrane 403 comprises partitions 403a that form the different pressure chambers D1-D4 as described in [0111-0112]).
It would have been obvious for a person of ordinary skill in the art, before the effective filing date of the claimed invention to have provided for an additional polishing head (fourth CMP head) with multiple chambers, and to have arranged those chambers differently (i.e. different from the first, second, and third CMP head), for the reasons given above.
With respect to claim 26, Yoshida, as modified, teaches the limitations of claim 25 above and further teaches wherein the diameter corresponding to the maximum removal rate of the second CMP head is radially offset from the inner sidewall of the peripheral pressure element of the first pressure control plate by a first distance and is radially offset from the outer sidewall of the peripheral pressure element of the first pressure control plate by a second distance, the second distance being less than the first distance (as explained in the rejection of claim 25 above, changing the distribution of pressure elements in terms of the boundaries/diameter of each pressure element, between the two CMP heads would be obvious to a person of ordinary skill in the art, with the polishing rate of each CMP element being minimal at the boundary of the pressure elements, and thus the claimed arrangement of claim 26 is also obvious , being the result of changing the distribution of pressure elements).
With respect to claim 29, Yoshida, as modified, teaches the limitations of claim 25 above however does not explicitly teach wherein a ratio of an annular width of a peripheral pressure element directly adjacent to the second innermost pressure element and an annular width of an overlap region defined between the outer sidewall of the second innermost pressure element and the inner sidewall of the peripheral pressure element is greater than or equal to approximately 3:1.
However, as in the rejection of claim 25, above, for the same reasons given by Yoshida of precision polishing at particular locations, and of having a lower polishing rate at boundaries of the pressure elements, a person of ordinary skill in the art, before the effective filing date of the claimed invention, would have found the arrangement of the pressure elements such that a ratio of an annular width of a peripheral pressure element directly adjacent to the second innermost pressure element and an annular width of an overlap region defined between the outer sidewall of the second innermost pressure element and the inner sidewall of the peripheral pressure element is greater than or equal to approximately 3:1 to be obvious, as a rearrangement of the pressure elements taught by Yoshida. The examiner notes (as already noted) that the claim, simply defines the dimensions (in the form of a annular width), and placement of pressure elements relative to each other, and that Yoshida already provides reason, as noted in the rejection of claim 25, to vary the dimensions and placement of pressure elements, and that the examiner does not find that claiming the arrangement in a particular way would have overcame the obviousness rejection, absent demonstration that the particular arrangement provides for a particular improvement over the prior art.
Claim(s) 17, 21 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yoshida (US Pub. 20150311097 A1) in view of Zhang-‘897 (US Pub. 20120277897 A1), as applied in the rejection of claim 25 above, and further in view of Zhang-‘373 (US Pub. 20120122373 A1, Okumura (JP 2000133623 A, translation attached as NPL on 11/17/2023) and as evidenced by Muramatsu (US Pat. 5981301 A).
With respect to claim 17, Yoshida, as modified, teaches of the apparatus of claim 25 (see rejection of claim 25 above), and further teaches a method (example 5 in fig. 14 and claim 8 of the pub) for chemical mechanical polishing ([0003,0004] upon which this improves and fig. 1 shows a slurry supply 32A-D, platen 30A-D, polishing pad 10, polishing head 31A-D) (CMP) of a workpiece, the method comprising: performing a first CMP process on a front-side surface of the workpiece with the first CMP head, and performing a second CMP process on the front-side surface of the workpiece with the second CMP head (method disclosed in claim 8 of PG Pub), and performing a third CMP process on the front-side surface of the workpiece with the third CMP head (see example 5 in fig. 14) wherein the first CMP process is performed before the second CMP process and the third CMP process is performed after the second CMP process (order described in [0120] from 31C -> 31D -> 31B; see figs. 8A, and 8B, the different pressure profiles of the CMP heads further explained in [0121-0122]).
Yoshida does not explicitly disclose: performing a thinning process on the workpiece, wherein after the thinning process and the first CMP process the front-side surface of the workpiece has a first total thickness variation (TTV) greater than 0.35 um; performing a first measurement of a planarity of the front-side surface of the workpiece; and that pressures exerted by the second plurality of pressure elements during a second CMP process are independently varied based on the first measurement of the planarity of the front-side surface of the workpiece after the first CMP process, and a real time measurement of the planarity of the front-side surface of the workpiece during the second CMP process.
Zhang-‘897, teaches the surface measurement apparatus as in claim 25 above, and further teaches of a CMP process, wherein,
a first measurement of a planarity of the front-side surface of the workpiece while performing a first CMP process (measuring a profile based on an in-situ measurement system in [0042]) and
wherein pressures exerted by a plurality of concentric pressure elements during second CMP process are independently varied based on the measured planarity of the to-be-polished surface after the first CMP process ([0072] – teaches of a combination of suitable chamber pressures; fig. 1 shows pressure chambers 146a, 146b, 146c; which are independently controlled as in [0008]; [0009] –“wherein the target removal profile may be generated from data collected in-situ during polishing of a first substrate at a first platen, and polishing the first substrate at a different second platen using the chamber pressure”, thus describing how a first measurement of a planarity are used for a second CMP process) .
Zhang-‘897 teaches that this helps compensate for any non-uniformity in the processing process ([0005]).
It would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to have incorporated the teachings Zhang-‘897 into the method of Yoshida, and to have controlled a second CMP process using planarity measurements from a first CMP process, as described above, for the reasons described above.
However, Yoshida, as modified does not explicitly teach a pressure exerted by the second plurality of pressure elements is independently varied based on a real time measurement of the planarity of the front-side surface of the workpiece during the second CMP process.
Zhang-‘373, in the same field of endeavor, teaches of a CMP method, wherein pressures exerted by a plurality of concentric pressure elements ([0020] – “a plurality of CMP head pressure zones of the one or more pressure regulators corresponding to the plurality of locations at the plurality of locations of the wafer”) during a CMP process ([0020]- “Thus it can be seen that a measured wafer uniformity measured in situ of a wafer at a plurality of locations of the wafer at a first time is fed back in a feedback loop to the pressure controller and the pressure controller in response to the measured wafer uniformity) are independently varied ([0019] -explains the independent control of pressure at various pressure zones) based a real time measurement of the planarity of the to-be-polished surface during the CMP process ([0011] - real-time wafer uniformity readings).
Zhang-‘373 teaches that this provides the advantage of increasing consumable life and reducing costs ([0011]).
It would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to have incorporated the teachings of Zhang-‘373, into the method of Yoshida, as modified, for the reasons explained above.
Okumura, in the same field of endeavor, relating to chemical mechanical polishing, teaches of a thinning process on the workpiece before performing a CMP process ([0005-0006], referring to a grinding process before performing a CMP process, grinding being a thinning process consistent with the instant disclosure). Okumura teaches that this provides the advantage of “obtain a sample surface with excellent flattening properties and with less surface roughness” ([0006]), and that the flatness of the workpiece after grinding is dependent on the grindstone used ([0015]).
It would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to have incorporated the teachings of Okumura, into Yoshida, as modified, and have incorporated a step of performing a thinning process on the workpiece before performing a CMP process, for the reasons given above in that doing so would have provided for excellent surface properties. One would have done skilled in the art would have so before the first CMP process, as Okumura teaches of doing this step before CMP.
As for the limitations of wherein after the thinning process and the first CMP process the front-side surface of the workpiece has a first total thickness variation (TTV) greater than 0.35 um, the TTV measurement is an result of the claimed process, and as evidenced by Muramatsu, depends on factors such as the wafer, pad hardness, rotation speed (Table 2, spanning col 7 and 8).
Thus, one of ordinary skill in the art, before the effective filing date of the claimed invention, would have been able to use the polishing method, taught by Yoshida, as modified, to obtain this TTV performance result.
Yoshida provides evidence that the purpose of a second CMP process is to provide for more fine profile control ([0121]) and of the effect lower polishing rate (increased uniformity/variation), at the boundaries between pressure elements ([0008]), thus one skilled in the art, before the effective filing date of the claimed invention would provide for a front-side surface of the workpiece has a first total thickness variation (TTV) greater than 0.35 um after the first CMP process, as this is dependent on parameters of the preceding processes, with the goal of subsequent processes to further refine the profile of the wafer.
With respect to claim 21, Yoshida, as modified teaches the limitations of claim 17 above, however, does not explicitly teach after the third CMP process the front-side surface of the workpiece has a second TTV less 0.3 um
However, the TTV measurement is a result of the claimed process, and as previously evidenced by Muramatsu, depends on factors such as the wafer, pad hardness, rotation speed (Table 2, spanning col 7 and 8).
Thus, one of ordinary skill in the art, before the effective filing date of the claimed invention, would have been able to use the polishing method, taught by Yoshida, as modified, to obtain this TTV performance result.
Claim(s) 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yoshida (US Pub. 20150311097 A1) in view of Zhang-‘897 (US Pub. 20120277897 A1) Zhang-‘373 (US Pub. 20120122373 A1, Okumura (JP 2000133623 A), Muramatsu (US Pat. 5981301 A), as applied in the rejection of claim 17 above, and further in view of Kitajima (JP 2000015574 A), and as further evidenced by Korovin (US Pub. 20020061716 A1).
With respect to claim 20, Yoshida, as modified teaches the limitations of claim 17 above, however does not explicitly teach wherein one or more additional CMP processes are performed on the front-side surface of the workpiece based on the first CMP head, the second CMP head, or the third CMP head until a final TTV of the front-side surface is less than or equal to a predefined value, wherein the predefined value is at least ten percent less than the first TTV.
Korovin, in the same field of endeavor, relating to polishing, provides evidence that the goal of polishing is to reduce surface irregularities and obtain a wafer with a substantially uniform thickness ([0003]).
Kitajima, in the same field of endeavor, relating to polishing, teaches of performing more than one polishing process when a flatness goal is not met ([0003], 3nd sub para.).
MPEP 2144.05 II provides that routine optimization of a result effective variable within prior art conditions, would have been obvious to a person of ordinary skill in the art.
It would have been obvious for one of ordinary skill in the art, before the effective filing date of the claimed invention, to have one or more additional CMP processes are performed on the front-side surface of the workpiece based on the first CMP head, the second CMP head, or the third CMP head in order to meet a specific polishing goal, as taught by Kitajima, using repolishing, as evidenced by Korovin which shows that goal of polishing is to reduce surface irregularities and obtain a wafer with a substantially uniform thickness. One skilled in the art, before the effective filing date of the claimed invention, would have understood this to mean that the TTV obtained by the system of Yoshida would be less after completion subsequent CMP processes to obtain a low TTV (the predefined value), given that that would have been the objective of doing polishing, with one selecting a final TTV being less than or equal to 10% of a first TTV as evidenced by the teachings of Korovin, wherein the goal is to obtain a wafer with a substantially uniform thickness. One of ordinary skill in the art, would have selected a final TTV being less than or equal to 10% of a first TTV, as a matter of routine optimization, of a result effective variable, with a reasonable exception of success.
Claim(s) 22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yoshida (US Pub. 20150311097 A1) in view of Zhang-‘897 (US Pub. 20120277897 A1), as applied in the rejection of claim 25 above, further in view of Zhang-‘373 (US Pub. 20120122373 A1).
With respect to claim 22, Yoshida, teaches the limitations of claim 25 above, and further teaches:
a first platen (Yoshida, 30D, fig. 1) wherein the first CMP head is configured to perform a first CMP process on a to-be-polished surface of a workpiece (Yoshida, 31D, fig. 1 analogous to 31a which holds a wafer for polishing, described in [0081-0082]),
a second platen (Yoshida 30C, fig. 1) wherein the second CMP head is configured to perform a second CMP process on the to-be- polished surface of the workpiece (Yoshida 31D, fig. 1 analogous to 31a which holds a wafer for polishing, described in [0081-0082]),
wherein the surface measurement apparatus is configured to measure a planarity of the first surface of the workpiece during the first and second CMP processes, wherein pressures exerted by the second plurality of pressure elements are continuously varied during the second CMP process based on a first measurement of the planarity of the first surface during the first CMP process however does not explicitly teach pressures exerted by the second plurality of pressure elements are continuously varied during the second CMP process based on wherein real time measurements of the planarity of the first surface during the second CMP process.
Zhang-‘373, in the same field of endeavor, teaches of a CMP system (abstract), wherein pressures exerted by a plurality of concentric pressure elements ([0020] – “a plurality of CMP head pressure zones of the one or more pressure regulators corresponding to the plurality of locations at the plurality of locations of the wafer”) during a CMP process ([0020]- “Thus it can be seen that a measured wafer uniformity measured in situ of a wafer at a plurality of locations of the wafer at a first time is fed back in a feedback loop to the pressure controller and the pressure controller in response to the measured wafer uniformity) are independently varied ([0019] -explains the independent control of pressure at various pressure zones) based a real time measurement of the planarity of the to-be-polished surface during the CMP process ([0011] - real-time wafer uniformity readings). Zhang-‘373 teaches that this provides the advantage of increasing consumable life and reducing costs ([0011]).
It would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to have incorporated the teachings of Zhang-‘373, as described above, for the reasons explained above; and to have placed a surface measurement apparatus on both the first and second CMP platens to utilize the teachings of Zhang-‘373 and Zhang-‘897.
Claim(s) 23 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yoshida (US Pub. 20150311097 A1) in view of Zhang-‘897 (US Pub. 20120277897 A1) and Zhang-‘373 (US Pub. 20120122373 A1), Okumura (JP 2000133623 A) and Kitajima (JP 2000015574 A), and Muramatsu (US Pat. 5981301 A), as applied in the rejection of claim 17 above and as further evidenced by Korovin (US Pub. 20020061716 A1).
With respect to claim 23, Yoshida, as modified teaches the limitations of claim 17 above, and further teaches wherein the surface measurement apparatus is configured to measure a first total thickness variation (TTV) of the first surface after the first CMP process and a second TTV of the first surface after the second CMP process (the surface measurement apparatus measures planarity/profile, which is a measure of total thickness variation, see rejection using Zhang-‘897 and Zhang-‘373 in claim 17 above) however does not explicitly teach wherein the polishing system is configured to perform one or more third CMP processes by virtue of the first CMP head or the second CMP head based on the first and second TTVs respectively being less than a predefined value.
Korovin, in the same field of endeavor, relating to polishing, provides evidence that the goal of polishing is to reduce surface irregularities and obtain a wafer with a substantially uniform thickness ([0003]).
Kitajima, also teaches of performing more than one polishing process when a flatness goal is not met ([0003], 3nd sub para.), Kitajima further teaches of judging whether repolishing is necessary based on a profile of the wafer (page 3, 6-8th paragraph), with the arrangement reducing errors (page 6 lines 1-8)
It would have been obvious for one of ordinary skill in the art, before the effective filing date of the claimed invention, to have the polishing system is configured to perform one or more third CMP processes by virtue of the first CMP head or the second CMP head based on the first and second TTVs respectively being less than a predefined value, as taught by Kitajima (determining whether repolishing is necessary based on the wafer profile), in order to reduce errors. One skilled in the art, would have understood, from the evidence shown by Korovin that the goal of polishing is to reduce surface irregularities and obtain a wafer with a substantially uniform thickness, and have thus based it on the first and second TTVs respectively being less than a predefined value.
Claim(s) 30-32 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yoshida (US Pub. 20150311097 A1).
With respect to claim 30, Yoshida discloses: A chemical mechanical polishing (CMP) system comprising:
a first CMP head configured to retain a workpiece, (31C, fig. 1 analogous to 31a which holds a wafer, described in [0081-0082]), the first CMP head comprising a first plurality of pressure elements that are concentric about a central axis of the first CMP head and disposed across a first pressure control plate (pressure control plate analogous to instant disclosure shown in ann. fig. 6; the arrangements shown in fig. 9, C1-C4 being pressure elements; explained in [0123]; [0106, 0112] provide for the pressure elements to be concentrically arranged, with annular/circular elements, which are placed around a central axis); a first innermost pressure element of the first plurality of pressure elements having a first outer diameter defined by an outer sidewall of the first innermost pressure element (since the pressure elements are concentric/annular, they have a sidewall at the perimeter, of each element), and peripheral pressure elements of the first plurality of pressure elements having respective annular thicknesses defined between respective inner and outer sidewalls of the respective peripheral pressure elements of the first plurality of pressure elements (all pressure elements have annular thicknesses defined by the sidewalls, shown as 403a, in fig. 6, and the pressure elements shown in fig. 9 are also delineated by sidewalls); and
a second CMP head configured to retain the workpiece (31D, fig. 1 analogous to 31a which holds a wafer, described in [0081-0082]), the second CMP head comprising a second plurality of pressure elements that are concentric about a central axis of the second CMP head and disposed across a second pressure control plate (the arrangements shown in fig. 9, D1-D4 being pressure elements; explained in [0123], [0106, 0112] provide for the pressure elements to be concentrically arranged, with annular/circular element, which are placed around a central axis), the second plurality of pressure elements and the first plurality of pressure elements having the same number of pressure elements as one another (the number of pressure elements can be the same, in this case there are 4 pressure elements, however it is noted that there is no particular limitation on the number of pressure chambers in each of the two heads as long as there is at least two ([0112,0116]), a second innermost pressure element of the second plurality of pressure elements having a second outer diameter defined by an outer sidewall of the second innermost pressure element of the second plurality of pressure elements (since the pressure elements are concentric/annular, they have a sidewall at the perimeter, of each element), and peripheral pressure elements of the second plurality of pressure elements having respective annular thicknesses defined between respective inner and outer sidewalls of the respective peripheral pressure elements of the second plurality of pressure elements (all pressure elements have annular thicknesses defined by the sidewalls, shown as 403a, in fig. 6, and the pressure elements shown in fig. 9 are also delineated by sidewalls); and
wherein the first CMP head is configured to have a first removal profile on the first surface of the workpiece and the second CMP head is configured to have a second removal profile on the first surface (both CMP heads have different removal profiles, see fig. 8A, 8B, [0121, 0122]), wherein the CMP system is configured to have a combined removal profile on the first surface based on the first removal profile and the second removal profile (this functional effect would occur when polishing is done on one CMP head and subsequent polishing is done on a second, see [0122]),
wherein the first removal profile has minimum removal rates at inner and outer sidewalls of a peripheral pressure element of the first pressure control plate and has a maximum removal rate at a diameter corresponding to a midpoint between the inner and outer sidewalls of the peripheral pressure element of the first pressure control plate (see fig. 8A, 8B, [0121, 0122]; see also [0008], which also describes, in addition to [0122] how at the boundary of the pressure elements/chambers there is a low removal rate) and the second removal profile of the second CMP head has a maximum removal rate at a diameter that is radially offset from the inner and outer sidewalls of the peripheral pressure element of the first pressure control plate (because the boundaries of the second CMP head pressure elements are offset radially from the inner/outer sidewalls of the first CMP head, as in fig. 9, see comparison between C1-C4, and D1-D4, the effect would be as claimed),
a third CMP head configured to retain the workpiece, (Yoshida, 31b, fig. 1, analogous to 31a which holds a wafer, described in [0081-0082]),
Yoshida does not explicitly disclose
wherein the second outer diameter of the second innermost pressure element in the second plurality of pressure elements is greater than the first outer diameter of the first innermost pressure element in the first plurality of pressure elements, wherein when a line normal to upper surfaces of the first and second CMP heads passes through the central axis of the first CMP head and passes through the central axis of the second CMP head, the outer sidewalls of the peripheral pressure elements, respectively, in the first plurality of pressure elements correspond to a first plurality of outer diameters, respectively, and the outer sidewalls of the peripheral pressure elements, respectively, in the second plurality of pressure elements correspond to a second plurality of outer diameters, respectively, that are larger than the first plurality of outer diameters, respectively, to define a first plurality of overlap regions, respectively, the overlap regions of the first plurality of overlap regions having respective annular widths, the second removal profile of the second CMP head has a maximum removal rate at a diameter that is radially offset from the inner and outer sidewalls of the peripheral pressure element of the first pressure control plate, and wherein the combined removal profile exhibits minimum removal rates at respective midpoints of the respective annular widths of the respective first plurality of overlap regions; and wherein the diameter corresponding to the maximum removal rate of the second CMP head is radially offset from the inner sidewall of the peripheral pressure element of the first pressure control plate by a first distance and is radially offset from the outer sidewall of the peripheral pressure element of the first pressure control plate by a second distance, the second distance being less than the first distance, wherein the third CMP head comprises a third plurality of pressure elements that are concentric about a central axis of the third CMP head and disposed across a third pressure control plate, the third plurality of pressure elements and the first plurality of pressure elements having the same number of pressure elements as one another; a third innermost pressure element of the third plurality of pressure elements having a third outer diameter defined by an outer sidewall of the third innermost pressure element of the third plurality of pressure elements, and peripheral pressure elements of the third plurality of pressure elements having respective annular thicknesses defined between respective inner and outer sidewalls of the respective peripheral pressure elements of the third plurality of pressure elements, wherein the third outer diameter of the third innermost pressure element in the third plurality of pressure elements is greater than the first outer diameter of the first innermost pressure element in the first plurality of pressure elements and is greater than the second outer diameter of the second innermost pressure element in the second plurality of pressure elements, wherein when the line normal to upper surfaces of the first and second CMP heads passes through the central axis of the third CMP head, the outer sidewalls of the peripheral pressure elements, respectively, in the third plurality of pressure elements correspond to a third plurality of outer diameters, respectively, that are larger than the second plurality of outer diameters, respectively, to define a second plurality of overlap regions, respectively, and wherein a center of an innermost peripheral pressure element of the third CMP head corresponds to a maximum removal rate of the innermost peripheral pressure element of the third CMP head and the center of the innermost peripheral pressure element of the third CMP head is radially offset from the inner and outer sidewalls of the peripheral pressure element of the first pressure control plate.
However, Yoshida does disclose that the two arrangements of pressure elements in the first and second CMP head are different and that in doing so one can reduce the number of pressure elements in a single CMP head while achieving the same CMP effect – achieving precise profile control ([0124]), and that different CMP heads have different costs ([0024]). As noted above, Yoshida also discloses that there is no particular limitation on the number of pressure chambers in each of the two heads as long as there is at least two ([0112,0116]).
Furthermore, as previously noted, Yoshida also describes a polishing step using pressure chambers C1-C4 would result in a lower polishing rate at the boundaries of the pressure chambers in [0122].
Yoshida further teaches an arrangement of where the outermost pressure elements of the second plurality of pressure elements are arranged to have a narrow width (fig. 10, [0055], referring to an arrangement of D1-D4, specifically D2-D4), and explains that such an arrangement is to provide fine/precise at a peripheral portion of an wafer ([0055,0125]), and also teaches of a narrow width of an innermost set of pressure elements (fig. 12, [0057], referring to an arrangement of D1-D4, specifically D1-D3), and teaches that this provides for fine/precise control at a central portion of a wafer ([0057,0125]).
MPEP 2144.05 II provides that routine optimization of a result effective variable within prior art conditions, would have been obvious to a person of ordinary skill in the art and MPEP 2144.04 IV provides that changes in size/proportion would have been obvious to a person of ordinary skill in the art.
It would have been obvious for one of ordinary skill in the art, before the effective filing date of the claimed invention to have made a pressure element distribution wherein the second outer diameter of the second innermost pressure element in the second plurality of pressure elements is greater than the first outer diameter of the first innermost pressure element in the first plurality of pressure elements, wherein when a line normal to upper surfaces of the first and second CMP heads passes through the central axis of the first CMP head and passes through the central axis of the second CMP head, the outer sidewalls of the peripheral pressure elements, respectively, in the first plurality of pressure elements correspond to a first plurality of outer diameters, respectively, and the outer sidewalls of the peripheral pressure elements, respectively, in the second plurality of pressure elements correspond to a second plurality of outer diameters, respectively, that are larger than the first plurality of outer diameters, respectively, to define a first plurality of overlap regions, respectively, the overlap regions of the first plurality of overlap regions having respective annular widths, the second removal profile of the second CMP head has a maximum removal rate at a diameter that is radially offset from the inner and outer sidewalls of the peripheral pressure element of the first pressure control plate, and wherein the combined removal profile exhibits minimum removal rates at respective midpoints of the respective annular widths of the respective first plurality of overlap regions; and wherein the diameter corresponding to the maximum removal rate of the second CMP head is radially offset from the inner sidewall of the peripheral pressure element of the first pressure control plate by a first distance and is radially offset from the outer sidewall of the peripheral pressure element of the first pressure control plate by a second distance, the second distance being less than the first distance, as a optimization of a result effective variable (size/placement of pressure elements) or a change in size/proposition for the reasons given above of selecting an appropriate placement of pressure element boundaries for fine polishing at specific areas, which would result in the claimed limitations, as the claimed arrangement is obtained by varying the position of the pressure element boundaries to obtain different pressure element widths, to result in the claimed arrangement where the arrangement of the first and second CMP heads are defined with respect to their annular diameter and size of an overlap when the arrangement is compared in a stacked vertical arrangement. A person of ordinary skill in the art would have made the modification with a reasonable expectation of success.
The claimed limitations of “wherein the combined removal profile exhibits minimum removal rates at respective midpoints of the respective annular widths of the respective first plurality of overlap regions; and wherein the diameter corresponding to the maximum removal rate of the second CMP head is radially offset from the inner sidewall of the peripheral pressure element of the first pressure control plate by a first distance and is radially offset from the outer sidewall of the peripheral pressure element of the first pressure control plate by a second distance, the second distance being less than the first distance” depend on the arrangement of the pressure elements and, in view of Yoshida above, are obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, given that one would select the boundaries (to result in different widths and overlap regions) of the pressure elements for the reasons given by Yoshida, which would functionally cause the claimed effect given the previous explanation of how the polishing rate is reduced at the boundaries of the pressure elements.
As for the specifics regarding the third CMP head, Yoshida, as noted above, teaches that the two arrangements of pressure elements in the first and second CMP head are different and that in doing so one can reduce the number of pressure elements in a single CMP head while achieving the same CMP effect – achieving precise profile control (Yoshida, [0124]), and that different CMP heads have different costs (Yoshida, [0024]). Yoshida also discloses that there is no particular limitation on the number of pressure chambers in each of the two heads as long as there is at least two (Yoshida, [0112,0116]) and that the configuration of the CMP heads may be arbitrary changed (Yoshida, [0126]), and that using pressure chambers C1-C4 would result in a lower polishing rate at the boundaries of the pressure chambers in [0122], thus demonstrating the need to polish wafers with an arrangement that is different, and that there is no particular limitation on the number of pressure chambers in each of the two heads as long as there is at least two (Yoshida, [0112,0116]), and that multi-zone pressure heads can be costly, and that there is a limit to the number of pressure zones/chambers, but more pressure zones/elements provide for more control (Yoshida, [0006-0008]).
Yoshida also teaches that the polishing heads may be arranged in any way (Yoshida, [0126]). As an example, in Yoshida, Example 5 of Fig. 14 and described in [0129] for when only use of multi-pressure zone/element polishing heads (“exemplary selection of polishing heads in a case of a small amount of polishing of a wafer, a high demand for planarization of a wafer surface, and a low demand for no defect”). As another example, in Yoshida, [0130-0131], Yoshida discloses of an arrangement where there are four CMP heads, with two having one structure and two having another structure defined by the membrane 403 (Yoshida, in fig. 6 the membrane 403 comprises partitions 403a that form the different pressure chambers D1-D4 as described in [0111-0112]).
MPEP 2144.05 II provides that routine optimization of a result effective variable within prior art conditions, would have been obvious to a person of ordinary skill in the art, MPEP 2144.04 IV provides that changes in size/proportion would have been obvious to a person of ordinary skill in the art, and MPEP 2144.04 VI provides that mere duplication of parts has no patentable significance unless a new and unexpected result is produced.
It would have been obvious for a person of ordinary skill in the art, before the effective filing date of the claimed invention to have provided for an additional polishing head (third CMP head) with multiple pressure elements, and to have arranged those pressure elements differently as a optimization of a result effective variable (size/placement of pressure elements), or a change in size/proportion for the reasons given above. It would have also been obvious for a person of ordinary skill in the art, before the effective filing date of the claimed invention to have provided a third polishing head with multiple pressure chambers as a duplication of one of the existing polishing heads with multiple pressure chambers, as a mere duplication of parts. A person of ordinary skill in the art would have made the modification with a reasonable expectation of success. The result would have been wherein the third CMP head comprises a third plurality of pressure elements that are concentric about a central axis of the third CMP head and disposed across a third pressure control plate, the third plurality of pressure elements and the first plurality of pressure elements having the same number of pressure elements as one another; a third innermost pressure element of the third plurality of pressure elements having a third outer diameter defined by an outer sidewall of the third innermost pressure element of the third plurality of pressure elements, and peripheral pressure elements of the third plurality of pressure elements having respective annular thicknesses defined between respective inner and outer sidewalls of the respective peripheral pressure elements of the third plurality of pressure elements, wherein the third outer diameter of the third innermost pressure element in the third plurality of pressure elements is greater than the first outer diameter of the first innermost pressure element in the first plurality of pressure elements and is greater than the second outer diameter of the second innermost pressure element in the second plurality of pressure elements, wherein when the line normal to upper surfaces of the first and second CMP heads passes through the central axis of the third CMP head, the outer sidewalls of the peripheral pressure elements, respectively, in the third plurality of pressure elements correspond to a third plurality of outer diameters, respectively, that are larger than the second plurality of outer diameters, respectively, to define a second plurality of overlap regions, respectively, and wherein a center of an innermost peripheral pressure element of the third CMP head corresponds to a maximum removal rate of the innermost peripheral pressure element of the third CMP head and the center of the innermost peripheral pressure element of the third CMP head is radially offset from the inner and outer sidewalls of the peripheral pressure element of the first pressure control plate, this arrangement is an result that is obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, for the same reason that is provided with regards to the different between the arrangement pressure elements of the first and second CMP previously explained (in that Yoshida already provides the reasoning for varying the arrangement of the pressure elements, and the claim simply defines how the pressure elements are different in relative size and placement compared to another pressure element arrangement in a different CMP head).
With respect to claim 31, Yoshida, as modified teaches the limitations of claim 30 above, and further teaches wherein the diameter corresponding to the maximum removal rate of the second CMP head is radially offset from the inner sidewall of the peripheral pressure element of the first pressure control plate by a first distance and is radially offset from the outer sidewall of the peripheral pressure element of the first pressure control plate by a second distance, the second distance being less than the first distance (as explained in the rejection of claim 30 above, changing the distribution of pressure elements in terms of the boundaries/diameter of each pressure element, between the two CMP heads would be obvious to a person of ordinary skill in the art, with the polishing rate of each CMP element being minimal at the boundary of the pressure elements, and thus the claimed arrangement of claim 31 is also obvious, being the result of changing the distribution of pressure elements).
With respect to claim 32, Yoshida, as modified teaches the limitations of claim 30 above, however does not explicitly teach wherein a ratio of an annular width of a peripheral pressure element directly adjacent to the second innermost pressure element and an annular width of an overlap region defined between the outer sidewall of the second innermost pressure element and the inner sidewall of the peripheral pressure element is greater than or equal to approximately 3:1.
However, as in the rejection of claim 31, above, for the same reasons given by Yoshida of precision polishing at particular locations, and of having a lower polishing rate at boundaries of the pressure elements, a person of ordinary skill in the art, before the effective filing date of the claimed invention, would have found the arrangement of the pressure elements such that a ratio of an annular width of a peripheral pressure element directly adjacent to the second innermost pressure element and an annular width of an overlap region defined between the outer sidewall of the second innermost pressure element and the inner sidewall of the peripheral pressure element is greater than or equal to approximately 3:1 to be obvious, as a rearrangement of the pressure elements taught by Yoshida. The examiner notes (as already noted) that the claim, simply defines the dimensions (in the form of a annular width), and placement of pressure elements relative to each other, and that Yoshida already provides reason, as noted in the rejection of claim 31, to vary the dimensions and placement of pressure elements, and that the examiner does not find that claiming the arrangement in a particular way would have overcame the obviousness rejection, absent demonstration that the particular arrangement provides for a particular improvement over the prior art.
Claim(s) 33 and 35 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yoshida (US. Pub. 20150311097 A1), as applied in the rejection of claim 30 above, and further in view of Zhang-‘897 (US Pub. 20120277897 A1), Zhang-‘373 (US Pub. 20120122373 A1, Okumura (JP 2000133623 A, translation attached as NPL on 11/17/2023) and as evidenced by Muramatsu (US Pat. 5981301 A).
With respect to claim 33, Yoshida, as modified, teaches of the apparatus of claim 30 (see rejection of claim 30 above), and further teaches a method (example 5 in fig. 14 and claim 8 of the pub) for chemical mechanical polishing ([0003,0004] upon which this improves and fig. 1 shows a slurry supply 32A-D, platen 30A-D, polishing pad 10, polishing head 31A-D) (CMP) of a workpiece, the method comprising: performing a first CMP process on a front-side surface of the workpiece with the first CMP head, and performing a second CMP process on the front-side surface of the workpiece with the second CMP head (method disclosed in claim 8 of PG Pub), and performing a third CMP process on the front-side surface of the workpiece with the third CMP head (see example 5 in fig. 14) wherein the first CMP process is performed before the second CMP process and the third CMP process is performed after the second CMP process (order described in [0120] from 31C -> 31D -> 31B; see figs. 8A, and 8B, the different pressure profiles of the CMP heads further explained in [0121-0122]).
Yoshida does not explicitly disclose: performing a thinning process on the workpiece, wherein after the thinning process and the first CMP process the front-side surface of the workpiece has a first total thickness variation (TTV) greater than 0.35 um; performing a first measurement of a planarity of the front-side surface of the workpiece; and that pressures exerted by the second plurality of pressure elements during a second CMP process are independently varied based on the first measurement of the planarity of the front-side surface of the workpiece after the first CMP process, and a real time measurement of the planarity of the front-side surface of the workpiece during the second CMP process.
Zhang-‘897, in the same field of endeavor, related to chemical mechanical polishing, further teaches of a CMP process, wherein,
a first measurement of a planarity of the front-side surface of the workpiece while performing a first CMP process (measuring a profile based on an in-situ measurement system in [0042]) and
wherein pressures exerted by a plurality of concentric pressure elements during second CMP process are independently varied based on the measured planarity of the to-be-polished surface after the first CMP process ([0072] – teaches of a combination of suitable chamber pressures; fig. 1 shows pressure chambers 146a, 146b, 146c; which are independently controlled as in [0008]; [0009] –“wherein the target removal profile may be generated from data collected in-situ during polishing of a first substrate at a first platen, and polishing the first substrate at a different second platen using the chamber pressure”, thus describing how a first measurement of a planarity are used for a second CMP process) .
Zhang-‘897 teaches that this helps compensate for any non-uniformity in the processing process ([0005]).
It would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to have incorporated the teachings Zhang-‘897 into the method of Yoshida, and to have controlled a second CMP process using planarity measurements from a first CMP process, as described above, for the reasons described above.
However, Yoshida, as modified does not explicitly teach a pressure exerted by the second plurality of pressure elements is independently varied based on a real time measurement of the planarity of the front-side surface of the workpiece during the second CMP process.
Zhang-‘373, in the same field of endeavor, teaches of a CMP method, wherein pressures exerted by a plurality of concentric pressure elements ([0020] – “a plurality of CMP head pressure zones of the one or more pressure regulators corresponding to the plurality of locations at the plurality of locations of the wafer”) during a CMP process ([0020]- “Thus it can be seen that a measured wafer uniformity measured in situ of a wafer at a plurality of locations of the wafer at a first time is fed back in a feedback loop to the pressure controller and the pressure controller in response to the measured wafer uniformity) are independently varied ([0019] -explains the independent control of pressure at various pressure zones) based a real time measurement of the planarity of the to-be-polished surface during the CMP process ([0011] - real-time wafer uniformity readings).
Zhang-‘373 teaches that this provides the advantage of increasing consumable life and reducing costs ([0011]).
It would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to have incorporated the teachings of Zhang-‘373, into the method of Yoshida, as modified, for the reasons explained above.
Okumura, in the same field of endeavor, relating to chemical mechanical polishing, teaches of a thinning process on the workpiece before performing a CMP process ([0005-0006], referring to a grinding process before performing a CMP process, grinding being a thinning process consistent with the instant disclosure). Okumura teaches that this provides the advantage of “obtain a sample surface with excellent flattening properties and with less surface roughness” ([0006]), and that the flatness of the workpiece after grinding is dependent on the grindstone used ([0015]).
It would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to have incorporated the teachings of Okumura, into Yoshida, as modified, and have incorporated a step of performing a thinning process on the workpiece before performing a CMP process, for the reasons given above in that doing so would have provided for excellent surface properties. One would have done skilled in the art would have so before the first CMP process, as Okumura teaches of doing this step before CMP.
As for the limitations of wherein after the thinning process and the first CMP process the front-side surface of the workpiece has a first total thickness variation (TTV) greater than 0.35 um, the TTV measurement is an result of the claimed process, and as evidenced by Muramatsu, depends on factors such as the wafer, pad hardness, rotation speed (Table 2, spanning col 7 and 8).
Thus, one of ordinary skill in the art, before the effective filing date of the claimed invention, would have been able to use the polishing method, taught by Yoshida, as modified, to obtain this TTV performance result.
Yoshida provides evidence that the purpose of a second CMP process is to provide for more fine profile control ([0121]) and of the effect lower polishing rate (increased uniformity/variation), at the boundaries between pressure elements ([0008]), thus one skilled in the art, before the effective filing date of the claimed invention would provide for a front-side surface of the workpiece has a first total thickness variation (TTV) greater than 0.35 um after the first CMP process, as this is dependent on parameters of the preceding processes, with the goal of subsequent processes to further refine the profile of the wafer.
With respect to claim 35, Yoshida, as modified teaches the limitations of claim 33 above, however, does not explicitly teach after the third CMP process the front-side surface of the workpiece has a second TTV less 0.3 um
However, the TTV measurement is a result of the claimed process, and as previously evidenced by Muramatsu, depends on factors such as the wafer, pad hardness, rotation speed (Table 2, spanning col 7 and 8).
Thus, one of ordinary skill in the art, before the effective filing date of the claimed invention, would have been able to use the polishing method, taught by Yoshida, as modified, to obtain this TTV performance result.
Claim(s) 34 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yoshida (US Pub. 20150311097 A1) in view of Zhang-‘897 (US Pub. 20120277897 A1) Zhang-‘373 (US Pub. 20120122373 A1, Okumura (JP 2000133623 A), Muramatsu (US Pat. 5981301 A), as applied in the rejection of claim 33 above, and further in view of Kitajima (JP 2000015574 A), and as further evidenced by Korovin (US Pub. 20020061716 A1).
With respect to claim 34, Yoshida, as modified teaches the limitations of claim 33 above, however does not explicitly teach wherein one or more additional CMP processes are performed on the front-side surface of the workpiece based on the first CMP head, the second CMP head, or the third CMP head until a final TTV of the front-side surface is less than or equal to a predefined value, wherein the predefined value is at least ten percent less than the first TTV.
Korovin, in the same field of endeavor, relating to polishing, provides evidence that the goal of polishing is to reduce surface irregularities and obtain a wafer with a substantially uniform thickness ([0003]).
Kitajima, in the same field of endeavor, relating to polishing, teaches of performing more than one polishing process when a flatness goal is not met ([0003], 3nd sub para.).
MPEP 2144.05 II provides that routine optimization of a result effective variable within prior art conditions, would have been obvious to a person of ordinary skill in the art.
It would have been obvious for one of ordinary skill in the art, before the effective filing date of the claimed invention, to have one or more additional CMP processes are performed on the front-side surface of the workpiece based on the first CMP head, the second CMP head, or the third CMP head in order to meet a specific polishing goal, as taught by Kitajima, using repolishing, as evidenced by Korovin which shows that goal of polishing is to reduce surface irregularities and obtain a wafer with a substantially uniform thickness. One skilled in the art, before the effective filing date of the claimed invention, would have understood this to mean that the TTV obtained by the system of Yoshida would be less after completion subsequent CMP processes to obtain a low TTV (the predefined value), given that that would have been the objective of doing polishing, with one selecting a final TTV being less than or equal to 10% of a first TTV as evidenced by the teachings of Korovin, wherein the goal is to obtain a wafer with a substantially uniform thickness. One of ordinary skill in the art, would have selected a final TTV being less than or equal to 10% of a first TTV, as a matter of routine optimization, of a result effective variable, with a reasonable exception of success.
Response to Arguments
Applicant's arguments filed 01/21/2026 have been fully considered but they are not persuasive.
The applicant has argued that the cited art does not disclose a third CMP head with different distributions than the first and second CMP head (response page 13-14). The examiner respectfully submits that this arrangement would be obvious in view of the teachings of Yoshida, which provides reason (low polishing rate at the CMP pressure element boundaries, specific arrangement of the pressure elements for fine polishing in particular areas, and that the CMP heads may be arranged in any way, with no limitation in the number of pressures chambers each CMP head), and particularly provides that all 4 CMP heads of the CMP machine may be of multiple chambers. In light of those teachings, the examiner respectfully submits that the claimed arrangement is obvious.
The applicant also argues (response page 14-16) that the maximum removal rate being radially offset from inner and outer sidewalls of the peripheral pressure element of the first CMP head is not present in Yoshida, or the other cited references. The examiner again points out that this is a matter of obviousness, and in view of how, as noted above, the CMP head may have the pressure elements arranged to meet the claimed limitations. The examiner also points out that the removal rate is lower at the boundaries of pressure elements, and is highest in the middle, and with a rearrangement of pressure elements, the combined removal rate having the claimed profile can be predictably achieved. In response to how the applicant points out in Yoshida that the removal rate is aligned, and there is no motivation to combine figs. 10-12, as there is no overlap region, the examiner notes, for example Yoshida, fig. 12 where the pressure elements are concentrated at a particular location for fine polishing control, and that Yoshida provides reasoning to concentrate the pressure elements for fine control at particular locations, and the reasoning is sufficient for any particular pressure element arrangement (including to create overlap - examiner notes that the written part of the specification does not describe the overlap or provide a particular reason to have an overlap).
The applicant further argues (response page 16-17) that it was not demonstrated that the localized removal rate spreads are aligned with a midpoint of the outer pressure element. The examiner’s response to this is the same as the argument with respect to the radial offset of the maximum removal rate, in that it is derived from the particular pressure element arrangement.
The applicant then argues (response page 18) the particular relative widths of the pressure elements. Again, the examiner notes that, as previously, this arrangement would be obvious in view of the teachings of Yoshida, which provides reason (low polishing rate at the CMP pressure element boundaries, specific arrangement of the pressure elements for fine polishing in particular areas, and that the CMP heads may be arranged in any way, with no limitation in the number of pressures chambers each CMP head)
Regarding the arguments directed to claim 26 (response page 18-20), the applicant argues that the arrangement would change the principal of operation of Yoshida, in that the maximum polishing rate of one CMP head would be the minimum polishing rate of the second one, and with the modification, the result would not be flat. The examiner respectfully disagrees, as this ignores the teachings, present in for example fig. 12 of Yoshida (for fine control at particular locations), and would also ignore the reasoning of the present application in that the applicant is arguing that the instant claimed arrangement would not create a flat uniform wafer (see, for example, instant [0027]). The examiner did not rely on the principle of inherency for the claim
Regarding the dependent claims, there were no specific arguments.
Regarding new claim 30, the applicant argues that there is no overlap region with respect to the third polishing head, however for the same reasons as presented in the rejection of claim 25, providing a differently arranged CMP head (with its own overlap region) would have been obvious.
Applicant is invented to submit evidence (and arguments are not a substitute for evidence) that demonstrates an improvement over Yoshida so that the obviousness rejection can be reevaluated in light of the evidence.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/Steven Huang/Examiner, Art Unit 3723
/DAVID S POSIGIAN/Supervisory Patent Examiner, Art Unit 3723