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 .
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.
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 1-3 and 12-13 are rejected under 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph, as failing to comply with the written description requirement. The claims 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 inventors, at the time the application was filed, had possession of the claimed invention.
Claim 1 has been amended to incorporate negative limitations stating that the initial polishing and endpoint detection processes include “polishing the substrate without adjusting pressing forces on the substrate against the polishing surface based on a plurality of film thicknesses of the substrate”. Although there is no inherent ambiguity associated with negative limitations, they must have basis in the original disclosure or should be rejected under 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph, as failing to comply with the written description requirement. see MPEP §2173.05(i). Furthermore, although there may be circumstances in which it can be established that a skilled artisan would understand a negative limitation to necessarily be present in a disclosure, silence will not generally suffice to support a negative claim limitation. See Novartis Pharms. Corp. v. Accord Healthcare, Inc., 38 F.4th 1013, 2022 USPQ2d 569 (Fed. Cir. 2022).
The disclosure is silent as to the inclusion or exclusion of any adjustment of pressing forces during the initial polishing process and endpoint adjustment process.
Therefore, the negative limitations of “polishing the substrate without adjusting pressing forces on the substrate against the polishing surface based on a plurality of film thicknesses of the substrate” are new matter, and claim 1 is therefore rejected under 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph as failing to comply with the written description requirement. Claims 2-3 and 12-13 depend from claim 1 and are likewise rejected.
Claim Rejections - 35 USC § 103
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.
Claims 1-3 and 12-13 are rejected under 35 U.S.C. 103 as being unpatentable over Qian et al. (US 9242337, "Qian") in view of Hiroo et al. (US 9440327, "Hiroo") and David et al. (US 8892568, "David").
1. Qian teaches a polishing method (1600, see Qian figs. 16a-16d) comprising:
rotating a polishing table (120) that supports a polishing pad (110, Qian fig. 3 and 5:59-67); and
polishing a substrate (10) by pressing the substrate against a polishing surface (112) of the polishing pad (110) by a polishing head (140, see Qian fig. 3 and 1:34-42), the substrate (10) having a multilayered structure including a dielectric film (30) and a stopper layer (20) formed under the dielectric film (Qian figs. 2a-2c and 5:35-58),
wherein polishing the substrate includes an initial polishing process (1602-1620, see Qian figs. 16A-16B), a film-thickness profile adjustment process performed after the initial polishing process (1622, see Qian fig. 16B), and a polishing-end-point detection process performed after the film-thickness profile adjustment process (1632, See Qian fig. 16c),
the initial polishing process includes measuring a first torque for rotating the polishing table and determining an initial polishing end point based on the first torque (1612 may determine an initial endpoint by monitoring a torque, see Qian 21:34-49),
the film-thickness profile adjustment process is started from the initial polishing end point (1622 occurs immediately after first endpoint time occurs as part of 1620, see Qian fig. 16b),
the film-thickness profile adjustment process includes measuring a plurality of film thicknesses at a plurality of measurement points on the substrate, adjusting pressing forces on the substrate against the polishing surface based on the plurality of film thicknesses until a surface, to be polished (varying pressures in different zones based on factors including material thicknesses, see Qian 22:59-23:17), of the substrate becomes flat (target profile may be flat, see Qian 4:21-42),
the film-thickness profile adjustment process is terminated when a film-thickness index value has reached a film-thickness threshold value (endpoint may be determined when a value has reached a target index, see Qian 20:43-64),
the film-thickness index value is any one of an average of the plurality of film thicknesses, a preselected one of the plurality of film thicknesses, a maximum value of the plurality of film thicknesses, and a minimum value of the plurality of film thicknesses (Film thickness may be used as the index value, Qian 24:59-65; at least one index value may be a preselected index value for one of the zones, see Qian 12:57-65), and
the polishing-end-point detection process includes polishing the substrate without adjusting the pressing forces on the substrate against the polishing surface based on the plurality of film thicknesses of the substrate (Qian teaches a period between a final polishing parameter adjustment and endpoint detection process during which the substrate is polished without any adjustment occurring, See, e.g., the period between T0 and TE' in Qian fig. 13 or between blocks 1634 and 1636, in Qian fig. 16d), while measuring a second torque for rotating the polishing table and determining, based on the second torque, a polishing end point of the substrate at which the dielectric film on the stopper layer is removed and the stopper layer is exposed based on the torque (clearing endpoint detected via torque measurements, see Qian 22:41-55; stopper layer 20 is exposed at clearing endpoint, see Qian fig. 2c and 5:47-58).
Qian does not teach that the film-thickness threshold value is determined based on a point in time at which a thickness of the dielectric film is small enough to allow precise determining of the polishing end point of the substrate in the polishing-end-point detection process.
However, Hiroo teaches an endpoint detection method for a polishing system wherein the endpoint is determined based on a combination of an optical endpoint detection system and a torque current endpoint detection system, and wherein the endpoint is not detected until both the optical system and torque system have reached specific threshold values (see Hiroo fig. 12). Hiroo further teaches that the optical distinctive point (i.e., threshold) corresponds to a known film thickness (Hiroo 8:55-65), the torque threshold corresponds to a film removal (Hiroo 5:17-44), and that, because the torque signal will not change until a film is cleared, the torque error range (R2) will tend to lag that of the optical error range (R1, see Hiroo figs. 10-11 and 8:66-9:22). Furthermore, Hiroo teaches that the use of both sensors will greatly reduce the odds of insufficient polishing (Hiroo 10:58-11:8). Because the optical endpoint detection system is capable of triggering before a film has been specifically cleared, one of ordinary skill before the effective filing date would have understood that implementing the teachings of Hiroo in an AND condition as suggested would involve setting a film thickness threshold value for the optical system such that it triggered slightly before the torque system would begin to detect a cleared layer, so as to avoid underpolishing while minimizing the amount of overpolishing, (see, e.g. Hiroo figs. 10-11 and 10:43-11:8).
Consequently, It would have been obvious to one of ordinary skill in the art before the effective filing date to integrate the teachings of an improved endpoint detection method from Hiroo into the method of Qian such that the film-thickness threshold value is determined based on a point in time at which a thickness of the dielectric film is small enough to allow precise determining of the polishing end point of the substrate in the polishing-end-point detection process, as doing so would result in a more accurate detection of a polishing endpoint (Hiroo 10:54-57).
Qian as modified does not specifically teach that the initial polishing process includes polishing the substrate without adjusting pressing forces on the substrate against the polishing surface based on a plurality of film thicknesses of the substrate, while measuring a first torque for rotating the polishing table and determining an initial polishing end point at which a measured value of the first torque has reached a torque threshold value.
Hiroo teaches the presence of a change in torque between an initial stage of polishing and a stepped portion of a layer being removed (Hiroo figs. 2a-2b and 3), but does not formally describe it as an initial polishing process including polishing the substrate without adjusting pressing forces on the substrate against the polishing surface based on a plurality of film thicknesses of the substrate, while measuring a first torque for rotating the polishing table and determining an initial polishing end point at which a measured value of the first torque has reached a torque threshold value.
However, David teaches a polishing method (David fig. 13) comprising:
rotating a polishing table (120) that supports a polishing pad (110); and
polishing a substrate (10) by pressing the substrate against a polishing surface of the polishing pad by a polishing head (140, see David fig. 2 and 1:34-40), the substrate having a multilayered structure (see David fig. 1a),
wherein polishing the substrate includes an initial polishing process (polishing begins at 1302, clearance of a layer is detected at a time Tc as indicated by step 1310, see David fig. 13, 16:3-9) including polishing the substrate without adjusting pressing forces on the substrate against the polishing surface based on a plurality of film thicknesses of the substrate (adjusting forces in step 1316 occurs after detecting the layer clearance in step 1312, David fig. 13), while measuring a first torque for rotating the polishing table and determining an initial polishing end point at which a measured value of the first torque has reached a torque threshold value (detecting a clearance via a change in motor torque, which is analogous to the detected torque exceeding a threshold, David 16:61-67).
It would have been obvious to one of ordinary skill in the art before the effective filing date to integrate the teachings of a polishing method including an initial clearing step from David into the method of Qian as modified such that the initial polishing process included polishing the substrate without adjusting pressing forces on the substrate against the polishing surface based on a plurality of film thicknesses of the substrate, while measuring a first torque for rotating the polishing table and determining an initial polishing end point at which a measured value of the first torque has reached a torque threshold value, as doing so represents the combination of known prior art elements according to known methods, the results of such a combination being predictable to one of ordinary skill.
2. Qian as modified teaches the polishing method according to claim 1, wherein adjusting the pressing forces includes adjusting the pressing forces on the substrate against the polishing surface based on the plurality of film thicknesses (varying pressures in different zones based on measured index traces, Qian 21:11-33; index traces are associated with thicknesses, see Qian 14:51-67) such that a surface, to be polished, of the substrate becomes flat (targeting a flat profile, Qian 4:21-42).
3. Qian as modified teaches the polishing method according to claim 1, wherein measuring the plurality of film thicknesses includes irradiating the substrate with light (Qian 7:50-62), generating a plurality of spectra of reflected light from the plurality of measurement points on the substrate (Qian 8:1-22), and determining the plurality of film thicknesses based on the plurality of spectra (determining layer thicknesses from the measured spectra, Qian 8:52-9:57).
12. Qian as modified teaches the polishing method according to claim 1, wherein the multilayered structure of the substrate further includes an underlying layer (11) having multiple raised portions (11 includes raised portions, see Qian figs. 2a-2c), and the stopper layer is formed on the multiple raised portions (stopper layer 20 is formed on top of protrusions, see Qian figs. 2a-2c).
13. Qian as modified teaches the polishing method according to claim 1, wherein the stopper layer is made of silicon nitride (Qian 5:35-46).
Response to Arguments
Applicant's arguments filed 26 February, 2026 have been fully considered but they are not persuasive.
In response to applicant’s argument that there is no teaching, suggestion, or motivation to combine the references, the examiner recognizes that obviousness may be established by combining or modifying the teachings of the prior art to produce the claimed invention where there is some teaching, suggestion, or motivation to do so found either in the references themselves or in the knowledge generally available to one of ordinary skill in the art. See In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988), In re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992), and KSR International Co. v. Teleflex, Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007). In this case, one of ordinary skill would be motivated to combine the teachings of Hiroo with the teachings of Qian to improve the quality of endpoint detection.
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
Finally, regarding applicant’s arguments that Qian continues active control through an endpoint detection step, examiner notes that, as stated in the rejections above, Qian teaches that there is a period between the final adjustment and an endpoint actually being reached. As no adjustment occurs during this time, it satisfies the claim limitation.
Applicant’s remaining arguments with respect to claim(s) 1-3 and 12-13 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
For these reasons, applicant’s arguments are not persuasive.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JONATHAN R ZAWORSKI whose telephone number is (571)272-7804. The examiner can normally be reached Monday-Thursday 8:00-5:00, Fridays 9:00-1:00.
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/J.R.Z./Examiner, Art Unit 3723
/JOEL D CRANDALL/Examiner, Art Unit 3723
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