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 Arguments
Applicant’s arguments, see Page 6, filed 05/05/2026, with respect to rejections under 112(b) and 132(a) have been fully considered and are persuasive. The corresponding rejections and objections have been withdrawn.
Applicant's arguments filed 05/05/2026 have been fully considered but they are not persuasive.
Applicant argues that according to MPEP 716.02 objective evidence on non-obviousness such as unexpected results or criticality of claimed ranges, can rebut a prima facie case of obviousness, and that Examiner previously argues a prima facie case of obviousness, arguing that modifying the average pore size and truncating the tail end of the distribution would be a matter of routine experimentation. Applicant provides a declaration in order to demonstrate the specific ranges of claim 1 provide an unexpected improvement in defectivity while breaking a conventional technological trade-off. As discussed below, while Examiner does agree, that declaration demonstrates the unexpected result of the pad of example 1, Examiner respectfully disagrees, that the declaration is sufficient to establish the criticality of the claimed ranges of claim 1. As such Examiner does not find this argument persuasive.
Oath/Declaration
The declaration under 37 CFR 1.132 filed 03/17/2026 is insufficient to overcome the rejection of claim 1-6 based upon 103as set forth in the last Office action because:
While applicants’ declaration is related to the claimed invention and satisfies the requirement for Nexus (See MPEP 716.01(B)), MPEP 716.02(d) discusses unexpected results commensurate in scope with the claimed invention. Section II, discusses that in order to demonstrate that a claimed range is critical, applicants should compare a sufficient number of tests both inside and outside the claimed range to show criticality of the range. The declaration provides the results of 3 tests (Levels 1, 2 and 3) with level 1 being within the claimed range and levels 2 and 3 outside of the claimed range. And while the test appears to show the unexpected result of a large change in the number of defects/scratches on a test wafer, the declaration does not provide a sufficient number of tests to demonstrate the criticality of the entire claimed range.
Specifically, the claimed range of Claim 1 requires that the average pore diameter fall between 10-14 micrometers, 5% or less of the proportions be 25 micrometers or more, and 20% or less area proportions of 25 micrometers or more. While the single example of the pad falling within the claimed range is sufficient to provide evidence that the pad of Level 1 demonstrates unexpected results to the other levels of pads, there is not enough evidence to support the claimed ranges, especially the range of the average diameter of pores falling between 10-14 micro meters and the sum of the pores that are 25 micrometers or greater is 5% or less with respect to the total number of pores.
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The data of Tables 1 and 3 of the declaration broadly establishes that there seems to be a generally negative correlation between the average pore diameter and the number and area proportions of 25 micrometers or greater, and the resulting defects and scratches. Or in other words, as the average diameter of pores and the numerical and area proportions of the pores over 25 micrometers, decrease, the number of defects seen in the wafer seem to decrease, with a sharper decrease (the unexpected result) of 0-2 defects occurring at some point within the claimed ranges.
However, Examiner notes the following concerns upon reviewing the data provided by the table:
The polishing pad of level 1 has a significantly different number of pores to the 2 comparative examples, and it is unclear from the declaration what role if any the number of pores plays in the resulting number of defects/scratches on the wafer after polishing, while this seems to be a result of the method of suppressing the average pore size, it is unclear if the actual number of pores has an impact or if it is only the average size of the pores that affects defectivity.
Table 3 shows the results of each level of polishing pad on two different substrates, 16 and 50. As mentioned in the declaration, the testing conditions described in Para [0069] – [0071] of the specification were replicated. However, the cited paragraphs of the specification discuss that the test was performed on a plurality of both metal film and oxide film substrates, while the results of both comparative examples of the metal films are shown and only the result of 1 comparative sample of the oxide film is shown, while the specification indicates that the second comparative showed the same tendency as the first. It is unclear from the declaration if the substrates 16 and 51 are both metal film substrates, oxide film substrates or if they are one each. And as such it is unclear how the results between these tests should be compared, as the data could be showing the results of a single test for each type of substrate with each level of pad, or showing the results of two tests for one type of substrate for each level of pad.
The final result shown in Table 3, the substrate 51 polished at level 3 at a rate of 8674, shows a remarkably high number of defects/scratches at 22, compared to the remainder of the results which fall in the range of 0-7. Additionally, level 3 substrate 16 also fell within the 0-7 range, with 7 scratches, assuming the substrates of the same type (as discussed above in item 2) a difference in 3 times as many scratches between two tests, when the difference between the two tests of the other levels being 2 scratches and 0 respectively, this would suggest this result to be an outlier of some sort.
For assisting the discussion, Examiner has taken the data from Table 1 of the declaration and produced the following table.
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In this table the rows corresponding the values claimed is now showing the absolute value the difference of the boundary of the claimed range to the measured value; in order to quantify numerically how close each pad is to the boundaries of the claimed ranges.
When viewing the data like this, with respect to the average pore diameter and numerical proportion, the level 2 pad is closest to the boundaries of the claimed range, while the area proportion of level 1 is closest to the claimed range.
While the pad of level 1 is the pad with the claimed ranges and demonstrates the unexpected results. It is unclear at what point in these ranges the unexpected results begin to occur. For the remainder of this analysis, Examiner will focus on comparing the results of the tests of substrate 16 on all 3 levels of pads due to the concerns outlined above. If the range the unexpected results occur in are as claimed, then Examiner would expect to see some difference in the number of scratches as the values get closer to the claimed ranges. For the pads of Level 2 and 3, the 16th substrate showed the same number of scratches, which suggests that the critical amount for at least numerical proportion and the upper bound of average pore diameter to be closer the measured values of Level 1, suggesting that the critical range is narrower than that of the claimed range.
Additionally, as there is only a single example of a pad that falls within the claimed range, it is difficult to evaluate the criticality of the lower bound of the claimed ranges, as the pad the falls within the claimed range has a lower average pore diameter, numerical and area proportion under 25 micro meters. Examiner acknowledges that producing a pad where the numerical and area proportions are under 25 micro meters being 0% or less would not be feasible, but at least one additional example (preferably more) of a pad falling within the claimed range would allow for an analysis of full boundaries of the claimed ranges, as the two examples within the range could be compared to each other.
In view of the foregoing, when all of the evidence is considered, the totality of the rebuttal evidence of nonobviousness fails to outweigh the evidence of obviousness.
For the purposes of Compact prosecution
Examiner would like to state that claimed range seems to be broader than what the data offered in the declaration suggests to be critical, and that it is Examiner’s opinion that narrowing the range or providing additional data (especially examples of pads falling with in the claimed range) or both would likely be the best way to advance prosecution and establish criticality.
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) 1-5 are rejected under 35 U.S.C. 103 as being unpatentable over Miyasaka (JP2019069497A) in view of Kulp (US 20070275226 A1) and Qian (US 20160176022 A1)
A polishing pad comprising:
a polishing layer (101) that has a polishing surface for performing a polishing process on an item to be polished (See Para [0018] “The polishing layer 101 is a layer that comes into contact with an object to be polished and performs polishing.”),
wherein the polishing layer includes hollow microspheres that form pores within the polishing layer (See Para [0024] “In the polishing pad 100, the polishing layer 101 includes a polymer 110 and microspheres 111.”),
but does not explicitly disclose
a cross-section of the polishing layer has an average pore diameter of 10-14µm, in a histogram of pore diameters in the cross-section of the polishing layer where a bin width is 1µm,
a sum of pores that are 25 µm or greater is 5% or less with respect to the total number of pores in the cross-section, and
a sum of areas of the pores in each bin that is 25 µm or greater is 20% or less with respect to a total area of the pores in the cross-section.
However, Miyasaka discloses a polishing pad wherein a cross section of the polishing layer has an average pore diameter of 10-20µm (See Para [0009] “In the polishing pad, the microspheres dispersed in the polyurethane resin may have an average particle size of 10 to 20 μm. In such a polishing pad, the average particle size of the microspheres contained in the polishing layer is 10 μm or more and 20 μm or less, so that the polishing layer can polish the object to be polished more precisely.”).
It would be obvious to one of ordinary skill in the art before the effective filling date of the invention to modify the range of average pore diameters from 10-20 µm to 10-14 µm. Miyasaka discloses that an average pore size of 20 µm or less is desirable as it increases the precision of the polishing operation undertaken by the pad (See Para [0058] “In the polishing pad 100 manufactured in this manner, the average particle size of the microspheres 111 contained in the polishing layer 101 is controlled to be between 10 μm and 20 μm, and the density of the polishing layer 101 is adjusted to be between 0.6 g/cm NER7 and 0.9 g/cm NER8. This allows the object to be polished more precisely than in a polishing layer in which microspheres 111 with an average particle size larger than 20 μm are dispersed.”), additionally, it has been held that in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. See MPEP 2144.05 I.
However, Miyasaka as modified does not disclose
in a histogram of pore diameters in the cross-section of the polishing layer where a bin width is 1 µm,
a sum of pores that are 25 µm or greater is 5% or less with respect to the total number of pores in the cross-section, and
a sum of areas of the pores in each bin that is 25 µm or greater is 20% or less with respect to a total area of the pores in the cross-section.
However, Kulp discloses a polishing pad for a chemical mechanical polishing process wherein the polishing pad is porous. Specifically teaching in Para [0024] “Preferably, the polishing pad has a porosity or filler concentration of 0.2 to 70 volume percent. Most preferably, the polishing pad has a porosity or filler concentration of 0.3 to 65 volume percent. Preferably the pores or filler particles have a weight average diameter of 1 to 100 µm. Most preferably, the pores or filler particles have a weight average diameter of 10 to 90 µm. The nominal range of expanded hollow-polymeric microspheres' weight average diameters is 15 to 90 µm Furthermore, a combination of high porosity with small pore size can have particular benefits in reducing defectivity. For example, a pore size of 2 to 50 µm constituting 25 to 65 volume percent of the polishing layer facilitates a reduction in defectivity. Furthermore, maintaining porosity between 40 and 60 percent can have a particular benefit to defectivity.” Kulp additionally discloses the market need for reduced defectivity in Para [0001]- [0005] specifically stating in Para [0005] “There is an ongoing need for additional polishing pads that have superior planarization ability in combination with improved defectivity performance. In particular, there is a desire for polishing pads suitable for polishing oxide/SiN with an improved combination of planarization and defectivity polishing performance.”
While Miyasaka discloses that reducing the average pore size is less than 20 µm results in a pad that allows for more precise polishing (See at least Para [0005] “With the increasing variety and precision of polished objects, there is a demand for polishing pads with high density and small bubble diameters (20 μm or less).” And Para [0007] “In such a polishing pad, the average particle size of the microspheres contained in the polishing layer is 20 μm or less, so that the polishing layer can polish the object to be polished more precisely.”).
Finally, Qian discloses that a histogram charting the diameter of pore sizes in a histogram is a known way of analyzing the average pore sizes of a polishing pad (See figures 4, 4a, 5 and 5a).
It would be obvious for one of ordinary skill in the art before the effective filling date of the invention to modify the average size of pores present in the polishing pad such that in a histogram of pore diameters in the cross-section of the polishing layer where a bin width is 1 µm,
a sum of pores that are 25 µm or greater is 5% or less with respect to the total number of pores in the cross-section, and
a sum of areas of the pores in each bin that is 25 µm or greater is 20% or less with respect to a total area of the pores in the cross-section.
Based on the disclosure of Kulp (cited above) and Miyasaka (cited above) the average size of a pore in a polishing pad is a result effective variable, such that lowering the average pore size increases precision and improves defectivity for the polishing pad. Limiting the pore size of the polishing pad such that:
in a histogram of pore diameters in the cross-section of the polishing layer where a bin width is 1 µm,
a sum of pores that are 25 µm or greater is 5% or less with respect to the total number of pores in the cross-section, and
a sum of areas of the pores in each bin that is 25 µm or greater is 20% or less with respect to a total area of the pores in the cross-section.
Would be a matter of routine experimentation that would be obvious to one of ordinary skill in the art before the effective filling date of the invention (See MPEP 2144.05 II).
Regarding Claim 2, Miyasaka as modified discloses all the limitations of claim 1 and suggests but does not explicitly disclose wherein a sum of the pores in each bin that is 30 µm or greater is 3% or less with respect to the total number of pores in the polishing surface, and a sum of areas of the pores in each bin that is 30 µm or greater is 10% or less with respect to a total area of the pores in the polishing surface.
It would be obvious for one of ordinary skill in the art before the effective filling date of the invention to modify the average size of pores present in the polishing pad such that
wherein a sum of the pores in each bin that is 30 µm or greater is 3% or less with respect to the total number of pores in the polishing surface, and a sum of areas of the pores in each bin that is 30 pm or greater is 10% or less with respect to a total area of the pores in the polishing surface.
Based on the disclosure of Kulp (cited above) and Miyasaka (cited above) the average size of a pore in a polishing pad is a result effective variable, such that lowering the average pore size increases precision and improves defectivity for the polishing pad. Limiting the pore size of the polishing pad such that:
wherein a sum of the pores in each bin that is 30 µm or greater is 3% or less with respect to the total number of pores in the polishing surface, and a sum of areas of the pores in each bin that is 30 µm or greater is 10% or less with respect to a total area of the pores in the polishing surface.
Would be a matter of routine experimentation that would be obvious to one of ordinary skill in the art before the effective filling date of the invention (See MPEP 2144.05 II).
Regarding Claim 3, Miyasaka discloses all the limitations of claim 1 but does not explicitly disclose wherein the hollow microsphere are derived from unexpanded hollow microspheres having a median diameter (D50) of 6 µm.
However, Miyasaka discloses utilizing microspheres having an average particle size of 5 μm or more and 20 μm or less
See Para [0011] “In order to achieve the above object, a method for manufacturing a polishing pad according to one embodiment of the present invention includes preparing a liquid containing microspheres having an average particle size of 5 μm or more and 20 μm or less and an outer shell made of a thermoplastic resin, and a prepolymer.”
As Miyasaka discloses that heat-expanding microspheres are used to form the pores in the polishing pad (See Para [0005] “In all of the above patent documents, heat-expandable microspheres are largely expanded to obtain a low-density polishing pad.”) and discusses an issue in manufacturing that finding microspheres with a diameter of 20µm or less is difficult (See Para [0005] “However, only pre-expanded microspheres with a bubble diameter of 20 μm or more are commercially available, and heat-expandable microspheres easily expand to a size of 20 μm or more due to the heat of reaction of the resin to be mixed, making it difficult to manufacture polishing pads with bubble diameters of 20 μm or less.”) which Miyasaka seeks to solve (discussed in Para [0011]) as such one of ordinary skill in the art before the effective filling date of the invention would find it obvious to utilize smaller unexpanded hollow microspheres such as unexpanded microspheres having a median diameter (D50) of 6µm or less. would assist in lowering the average pore diameter which is desirable as discussed in the rejection of claim 1 above.
Regarding Claim 4, Miyasaka discloses:
A manufacturing method for manufacturing a polishing pad including a polishing layer that has a polishing surface for performing a polishing process on an item to be polished (See Para [0018] “The polishing layer 101 is a layer that comes into contact with an object to be polished and performs polishing.”),
wherein the polishing layer includes hollow microspheres that form pores within the polishing layer (See Para [0024] “In the polishing pad 100, the polishing layer 101 includes a polymer 110 and microspheres 111.”),
the polishing layer is formed by mixing and reacting a urethane bond-containing polyisocyanate compound, a curing agent and unexpanded hollow microspheres (See Para [0025] “The polymer 110 may be a polymer formed by a polymerization reaction of a prepolymer and a curing agent. Such polymers include polyurethane resins. Polyurethane is a preferred polymer 110 because it is readily available, easily processable, and has favorable abrasive properties.” And Para [0026] “The prepolymer can be a compound having an isocyanate group terminal (hereinafter referred to as an isocyanate compound), which is a compound obtained by reacting a polyisocyanate compound with a polyol compound under commonly used conditions, and which contains a polyurethane bond and an isocyanate group in the molecule. Furthermore, other components may be contained in the polyurethane bond-containing isocyanate compound within the range that does not impair the effects of the present invention.”
But does not explicitly disclose
a cross-section of the polishing layer has an average pore diameter of 10-14 µm, in a histogram of pore diameters in the cross-section of the polishing layer where a bin width is 1 µm,
a sum of pores that are 25 µm or greater is 5% or less with respect to the total number of pores in the cross-section, and
a sum of areas of the pores in each bin that is 25 µm or greater is 20% or less with respect to a total area of the pores in the cross-section, and
the hollow microspheres having a median diameter (D50) of 6 µm less.
However, Kulp discloses a polishing pad for a chemical mechanical polishing process wherein the polishing pad is porous. Specifically teaching in Para [0024] “Preferably, the polishing pad has a porosity or filler concentration of 0.2 to 70 volume percent. Most preferably, the polishing pad has a porosity or filler concentration of 0.3 to 65 volume percent. Preferably the pores or filler particles have a weight average diameter of 1 to 100 µm. Most preferably, the pores or filler particles have a weight average diameter of 10 to 90 µm. The nominal range of expanded hollow-polymeric microspheres' weight average diameters is 15 to 90 µm Furthermore, a combination of high porosity with small pore size can have particular benefits in reducing defectivity. For example, a pore size of 2 to 50 µm constituting 25 to 65 volume percent of the polishing layer facilitates a reduction in defectivity. Furthermore, maintaining porosity between 40 and 60 percent can have a particular benefit to defectivity.” Kulp additionally discloses the market need for reduced defectivity in Para [0001]- [0005] specifically stating in Para [0005] “There is an ongoing need for additional polishing pads that have superior planarization ability in combination with improved defectivity performance. In particular, there is a desire for polishing pads suitable for polishing oxide/SiN with an improved combination of planarization and defectivity polishing performance.”
While Miyasaka discloses that reducing the average pore size is less than 20 µm results in a pad that allows for more precise polishing (See at least Para [0005] “With the increasing variety and precision of polished objects, there is a demand for polishing pads with high density and small bubble diameters (20 μm or less).” And Para [0007] “In such a polishing pad, the average particle size of the microspheres contained in the polishing layer is 20 μm or less, so that the polishing layer can polish the object to be polished more precisely.”).
Finally, Qian discloses that a histogram charting the diameter of pore sizes in a histogram is a known way of analyzing the average pore sizes of a polishing pad (See figures 4, 4a, 5 and 5a).
It would be obvious for one of ordinary skill in the art before the effective filling date of the invention to modify the average size of pores present in the polishing pad such that in a histogram of pore diameters in the cross-section of the polishing layer where a bin width is 1 µm,
a sum of pores that are 25 µm or greater is 5% or less with respect to the total number of pores in the cross-section, and
a sum of areas of the pores in each bin that is 25 µm or greater is 20% or less with respect to a total area of the pores in the cross-section.
Based on the disclosure of Kulp (cited above) and Miyasaka (cited above) the average size of a pore in a polishing pad is a result effective variable, such that lowering the average pore size increases precision and improves defectivity for the polishing pad. Limiting the pore size of the polishing pad such that:
in a histogram of pore diameters in the cross-section of the polishing layer where a bin width is 1 µm,
a sum of pores that are 25 µm or greater is 5% or less with respect to the total number of pores in the cross-section, and
a sum of areas of the pores in each bin that is 25 µm or greater is 20% or less with respect to a total area of the pores in the cross-section.
Would be a matter of routine experimentation that would be obvious to one of ordinary skill in the art before the effective filling date of the invention (See MPEP 2144.05 II).
Additionally, Miyasaka discloses utilizing microspheres having an average particle size of 5 μm or more and 20 μm or less See Para [0011] “In order to achieve the above object, a method for manufacturing a polishing pad according to one embodiment of the present invention includes preparing a liquid containing microspheres having an average particle size of 5 μm or more and 20 μm or less and an outer shell made of a thermoplastic resin, and a prepolymer.”
As Miyasaka discloses that heat-expanding microspheres are used to form the pores in the polishing pad (See Para [0005] “In all of the above patent documents, heat-expandable microspheres are largely expanded to obtain a low-density polishing pad.”) and discusses an issue in manufacturing that finding microspheres with a diameter of 20µm or less is difficult (See Para [0005] “However, only pre-expanded microspheres with a bubble diameter of 20 μm or more are commercially available, and heat-expandable microspheres easily expand to a size of 20 μm or more due to the heat of reaction of the resin to be mixed, making it difficult to manufacture polishing pads with bubble diameters of 20 μm or less.”) which Miyasaka seeks to solve (discussed in Para [0011]) as such one of ordinary skill in the art before the effective filling date of the invention would find it obvious to utilize smaller unexpanded hollow microspheres such as unexpanded microspheres having a median diameter (D50) of 6µm or less. would assist in lowering the average pore diameter which is desirable as discussed in the rejection of claim 1 above.
Regarding Claim 5, Miyasaka as modified discloses all the limitations of claim 4 and in addition discloses wherein the reaction is performed under a temperature control so as not to exceed a temperature of 140°C (See Para [0051] “Using such a manufacturing apparatus 200, for example, a prepolymer and microspheres 111 are charged into the first storage tank 201. The average particle size of the microspheres 111 before being introduced into the first storage tank 201 is 5 μm or more and 20 μm or less, and more preferably 5 μm or more and 15 μm or less. The prepolymer may be an isocyanate compound. The second storage tank 202 contains a curing agent. The curing agent is a polyol-based curing agent and/or a polyamine-based curing agent. In order to stabilize the fluidity of each raw material, the first storage tank 201 and the second storage tank 202 are heated to a predetermined temperature. However, in order to minimize expansion of the microspheres 111, the temperature of the first storage tank 201 is preferably set to 50° C. or higher and 80° C. or lower. If the temperature is higher than 80° C., the microspheres 111 may expand.”).
Claim(s) 6 is rejected under 35 U.S.C. 103 as being unpatentable over Miyasaka (JP 2019069497 A) in view of Kulp (US 20070275226 A1), Shi (US 20190224813 A1) and Qian (US 20160176022 A1).
A polishing method for polishing an item to be polished using a polishing pad and abrasive grains,
wherein the polishing pad includes a polishing layer that has a polishing surface for performing a polishing process on an item to be polished (The polishing layer 101 is formed of a polymer 110 and microspheres 111, See Para [0002] “During polishing, the voids are open on the surface of the polishing pad, and polishing slurry is held in these openings, thereby progressing the polishing of the object to be polished.” Polymer 110 is an abrasive material See Para [0025] “The polymer 110 is the main constituent of the abrasive material. The polymer 110 may be a polymer formed by a polymerization reaction of a prepolymer and a curing agent. Such polymers include polyurethane resins. Polyurethane is a preferred polymer 110 because it is readily available, easily processable, and has favorable abrasive properties.”),
wherein the polishing layer includes hollow microspheres that form pores within the polishing layer (See Para [0024] “In the polishing pad 100, the polishing layer 101 includes a polymer 110 and microspheres 111.”),
polishing is performed by bringing the item to be polished into contact with the polishing surface of the polishing pad in the presence of the abrasive grains and rotating any one or both of the polishing pad and the polishing item to be polished (See Para [0022] “The polishing pad 100 is rotated by a polishing device while being pressed against an object to be polished, thereby polishing the object.”).
But does not explicitly disclose:
a cross-section of the polishing layer has an average pore diameter of 10-14µm, in a histogram of pore diameters in the cross-section of the polishing layer where a bin width is 1 µm,
a sum of pores that are 25 µm greater is 5% or less with respect to the total number of pores in the cross-section, and
a sum of areas of the pores in each bin that is 25 µm greater is 20% or less with respect to a total area of the pores in the cross-section,
the abrasive grains have diameters of 0.01-0.2 µm,
However, Miyasaka discloses a polishing pad wherein a cross section of the polishing layer has an average pore diameter of 10-20µm (See Para [0009] “In the polishing pad, the microspheres dispersed in the polyurethane resin may have an average particle size of 10 to 20 μm. In such a polishing pad, the average particle size of the microspheres contained in the polishing layer is 10 μm or more and 20 μm or less, so that the polishing layer can polish the object to be polished more precisely.”).
It would be obvious to one of ordinary skill in the art before the effective filling date of the invention to modify the range of average pore diameters from 10-20 µm to 10-14 µm. Miyasaka discloses that an average pore size of 20 µm or less is desirable as it increases the precision of the polishing operation undertaken by the pad (See Para [0058] “In the polishing pad 100 manufactured in this manner, the average particle size of the microspheres 111 contained in the polishing layer 101 is controlled to be between 10 μm and 20 μm, and the density of the polishing layer 101 is adjusted to be between 0.6 g/cm NER7 and 0.9 g/cm NER8. This allows the object to be polished more precisely than in a polishing layer in which microspheres 111 with an average particle size larger than 20 μm are dispersed.”), additionally, it has been held that in the case where the claimed range “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. See MPEP 2144.05 I.
However, Miyasaka as modified does not disclose
in a histogram of pore diameters in the cross-section of the polishing layer where a bin width is 1 µm,
a sum of pores that are 25 µm or greater is 5% or less with respect to the total number of pores in the cross-section, and
a sum of areas of the pores in each bin that is 25 µm or greater is 20% or less with respect to a total area of the pores in the cross-section.
However, Kulp discloses a polishing pad for a chemical mechanical polishing process wherein the polishing pad is porous. Specifically teaching in Para [0024] “Preferably, the polishing pad has a porosity or filler concentration of 0.2 to 70 volume percent. Most preferably, the polishing pad has a porosity or filler concentration of 0.3 to 65 volume percent. Preferably the pores or filler particles have a weight average diameter of 1 to 100 µm. Most preferably, the pores or filler particles have a weight average diameter of 10 to 90 µm. The nominal range of expanded hollow-polymeric microspheres' weight average diameters is 15 to 90 µm Furthermore, a combination of high porosity with small pore size can have particular benefits in reducing defectivity. For example, a pore size of 2 to 50 µm constituting 25 to 65 volume percent of the polishing layer facilitates a reduction in defectivity. Furthermore, maintaining porosity between 40 and 60 percent can have a particular benefit to defectivity.” Kulp additionally discloses the market need for reduced defectivity in Para [0001]- [0005] specifically stating in Para [0005] “There is an ongoing need for additional polishing pads that have superior planarization ability in combination with improved defectivity performance. In particular, there is a desire for polishing pads suitable for polishing oxide/SiN with an improved combination of planarization and defectivity polishing performance.”
While Miyasaka discloses that reducing the average pore size is less than 20 µm results in a pad that allows for more precise polishing (See at least Para [0005] “With the increasing variety and precision of polished objects, there is a demand for polishing pads with high density and small bubble diameters (20 μm or less).” And Para [0007] “In such a polishing pad, the average particle size of the microspheres contained in the polishing layer is 20 μm or less, so that the polishing layer can polish the object to be polished more precisely.”).
Finally, Qian discloses that a histogram charting the diameter of pore sizes in a histogram is a known way of analyzing the average pore sizes of a polishing pad (See figures 4, 4a, 5 and 5a).
It would be obvious for one of ordinary skill in the art before the effective filling date of the invention to modify the average size of pores present in the polishing pad such that in a histogram of pore diameters in the cross-section of the polishing layer where a bin width is 1 µm,
a sum of pores that are 25 µm or greater is 5% or less with respect to the total number of pores in the cross-section, and
a sum of areas of the pores in each bin that is 25 µm or greater is 20% or less with respect to a total area of the pores in the cross-section.
Based on the disclosure of Kulp (cited above) and Miyasaka (cited above) the average size of a pore in a polishing pad is a result effective variable, such that lowering the average pore size increases precision and improves defectivity for the polishing pad. Limiting the pore size of the polishing pad such that:
in a histogram of pore diameters in the cross-section of the polishing layer where a bin width is 1 µm,
a sum of pores that are 25 µm or greater is 5% or less with respect to the total number of pores in the cross-section, and
a sum of areas of the pores in each bin that is 25 µm or greater is 20% or less with respect to a total area of the pores in the cross-section.
Would be a matter of routine experimentation that would be obvious to one of ordinary skill in the art before the effective filling date of the invention (See MPEP 2144.05 II).
Additionally, Shi discloses a similar abrasive article, with abrasive grains of various sizes including, the abrasive grains have diameters of 0.01-0.2 µm (See Para [0036] “In at least one embodiment, the abrasive particles can include crystalline grains (i.e., crystallites), and may consist entirely of a polycrystalline material made of crystalline grains. In particular instances, the abrasive particles can include crystalline grains having a median grain size of not greater than 1.2 microns. In other instances, the median grain size can be not greater than 1 micron, such as not greater than 0.9 microns or not greater than 0.8 microns or even not greater than 0.7 microns. However, the nanocrystalline alumina particles may have an average crystallite size of not greater than 0.15 microns, such as not greater than 0.14 microns, not greater than 0.13 microns or even not greater than 0.12 microns. According to one non-limiting embodiment, the median grain size of the abrasive particles can be at least 0.01 microns, such as at least 0.05 microns or at least 0.1 microns or at least 0.2 microns or even at least 0.4 microns. It will be appreciated that the median grain size of the abrasive particles can be within a range between any of the minimum and maximum values noted above.”).
It would be obvious to one of ordinary skill in the art before the effective filing date of the invention to modify the polishing pad to have shaped abrasive grains the abrasive grains have diameters of 0.01-0.2 µm, as doing Shi teaches that doing so provides a higher fidelity to a grinding or polishing process. See Para [0035] “However, a non-shaped abrasive particle will have a generally random arrangement of the surfaces and edges, and generally will lack any recognizable two-dimensional or three dimensional shape in the arrangement of the surfaces and edges around the body. Moreover, non-shaped abrasive particles of the same group or batch generally lack a consistent shape with respect to each other, such that the surfaces and edges are randomly arranged when compared to each other. Therefore, non-shaped grains or crushed grains have a significantly lower shape fidelity compared to shaped abrasive particles.”
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
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/T.J.M./ Examiner, Art Unit 3723
/DAVID S POSIGIAN/ Supervisory Patent Examiner, Art Unit 3723
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