12630288 (P.T.A.B. Jun. 24, 2016)

Ex Parte Ward et al

Patent Trial and Appeal BoardJun 24, 2016

12630288 (P.T.A.B. Jun. 24, 2016)

UNITED STA TES p A TENT AND TRADEMARK OFFICE APPLICATION NO. FILING DATE FIRST NAMED INVENTOR 12/630,288 12/03/2009 WILLIAM WARD 29050 7590 06/28/2016 Thomas Omholt Patent Prosecution Agent CABOT MICROELECTRONICS CORPORATION 870 NORTH COMMONS DRIVE AURORA, IL 60504 UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia 22313-1450 www .uspto.gov ATTORNEY DOCKET NO. CONFIRMATION NO. 100412 9474 EXAMINER PHAM, THOMAS T ART UNIT PAPER NUMBER 1713 NOTIFICATION DATE DELIVERY MODE 06/28/2016 ELECTRONIC Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the following e-mail address( es): CMC_PROSECUTION@CABOTCMP.COM thomas_omholt@cabotcmp.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte WILLIAM WARD and TIMOTHY JOHNS Appeal2015-001626 Application 12/630,288 Technology Center 1700 Before JEFFREY T. SMITH, KAREN M. HASTINGS, and MICHAEL P. COLAIANNI, Administrative Patent Judges. SMITH, Administrative Patent Judge. DECISION ON APPEAL STATEMENT OF THE CASE This is an appeal under 35 U.S.C. Â§ 134 from a final rejection of claims 1-10, 12-16, 18, 20-27, 29-31, and 33. We have jurisdiction under 35 U.S.C. Â§ 6. Claim 1 is illustrative of the subject matter on appeal and is reproduced below: 1. A chemical-mechanical polishing (CMP) method for selectively removing silicon carbide from the surface of Appeal2015-001626 Application 12/630,288 substrate in preference to silicon dioxide, the method comprising the steps of: (a) contacting a surface of the substrate with a polishing pad and an aqueous CMP composition; and (b) causing relative motion between the substrate and the polishing pad while maintaining a portion of the aqueous CMP composition in contact with the surface between the pad and the substrate for a period of time sufficient to abrade at least a portion of the silicon carbide present in the substrate from the surface; wherein the aqueous CMP composition contains a particulate alumina-doped colloidal silica abrasive present at a concentration in the range of about 0.1 to about 5 percent by weight, and an acidic buffering agent providing a pH in the range of about 2 to about 7, the aqueous CMP composition being capable of abrading silicon carbide present on the surface of the substrate at a higher removal rate than the concurrent abrading of silicon dioxide present on the surface of the substrate. Appellants (App. Br. 3) request review of the following rejections from the Examiner's Final Action: I. Claims 1---6, 8, 10, 12-16, 18, 20-25, and 27 rejected under 35 U.S.C. Â§ 103(a) as unpatentable over Desai (US 2008/0057713 Al, published March 6, 2008) and Belov (US 2007 /0037892 Al, published February 15, 2007). II. Claims 1-3, 6, 7, 10, 12-16, 18, 20-23, 26, 27, 29-31, and 33 rejected under 35 U.S.C. Â§ 103(a) as unpatentable over Minamihaba (US 2003/0124850 Al, published July 3, 2003) and Belov. III. Claim 9 rejected under 35 U.S.C. Â§ 103(a) as unpatentable over Desai, Belov, and Takemiya (US 2008/0200033 Al, published August 21, 2008). 2 Appeal2015-001626 Application 12/630,288 We AFFIRM. Rejection I (claim 1) OPINION Prior Art Rejections1 After review of the respective positions provided by Appellants and the Examiner, we AFFIRM the Examiner's prior art rejection of claims 1---6, 8, 10, 12-16, 18, 20-25, and 27 under 35 U.S.C. Â§ 103(a) for the reasons presented by the Examiner and add the following for emphasis. Independent claim 1 is directed to a chemical-mechanical polishing (CMP) method that uses an aqueous CMP composition being capable of abrading silicon carbide present on the surface of the substrate that contains a particulate alumina-doped colloidal silica abrasive, The Examiner found Desai teaches a chemical-mechanical polishing (CMP) method for removing silicon carbide from a surface of a substrate that differs from the claimed invention in that Desai does not disclose (a) the use of alumina doped colloidal silica and (b) the composition being capable of abrading silicon carbide present on the surface of the substrate at a higher removal rate than the concurrent abrading of silicon dioxide present on the surface of the substrate. Final Act. 2--4; Desai i-fi-16, 7, 9, 11, 15-17, 19-21, 27. With respect to (a), the Examiner found Belov discloses the use of alumina doped silica abrasives to stabilize CMP compositions when 1 For Rejections I and II, Appellants do not argue any claim separate from the other. See Appeal Brief, generally. Accordingly, we select independent claim 1 as representative of the subject matter before us on appeal for these rejections. Claims 2-8, 10, 12-16, 18, 20-27, 29-31, and 33 stand or fall with independent claim 1. 3 Appeal2015-001626 Application 12/630,288 polishing a substrate in IC fabrication to avoid particle agglomeration that causes scratches and defects on the polished surface, Final Act. 3--4; Belov i-fi-f 10, 12-16, 27, 39, 43, 47. The Examiner determined it would have been obvious to one skilled in the art to use the doped colloidal silica abrasives of Belov in the CMP composition of Desai in view of Belov's disclosed benefits. Final Act. 3--4. With respect to (b ), the Examiner determined the aqueous CMP composition of Desai, as modified by Belov, is the same as the aqueous CMP composition specified in claim 1 and, thus, it must possess the quality of abrading silicon carbide present on the surface of the substrate at a higher removal rate than the concurrent abrading of silicon dioxide present on the surface of the substrate disclosed by Appellants. Final Act. 4; Ans. 10-11. Appellants argue one skilled in the art would not replace the abrasives in Desai' s CMP composition abrasive with the abrasives of Belov because Desai teaches increasing the abrasive concentration and the oxidizing agent concentration to increase silicon carbide polishing. App. Br. 5. Appellants further argue Belov teaches the benefits of doped colloidal silica particles for copper polishing only and there is simply no evidence from the prior art to show that the particles of Belov would function in the composition and method of Desai. App. Br. 5---6; Belov i-fi-12, 31. We are unpersuaded by Appellants' arguments and agree with the Examiner's determination of obviousness for the reasons provided by the Examiner. Ans. 9-11. Moreover, Desai discloses the use of alumina and colloidal silica as suitable abrasives for polishing a silicon carbide layer on a substrate. Desai i-fi-f l 0-11. "It is prima facie obvious to combine two compositions each of which is taught by the prior art to be useful for the 4 Appeal2015-001626 Application 12/630,288 same purpose, in order to form a third composition which is to be used for the very same purpose." In re Kerkhoven, 626 F.2d 846, 850 (CCPA 1980). On this record, Appellants have not provided any persuasive reasoning or credible evidence why one of ordinary skill in the art would not have predictably used a mixture of Desai's disclosed abrasives (i.e., alumina doped colloidal silica) as recited in claim 1, to abrade a silicon carbide layer on a substrate. Accordingly, we affirm the Examiner's prior art rejection of claims 1- 6, 8, 10, 12-16, 18, 20-25, and 27 for the reasons presented by the Examiner and given above. Rejection II (claim 1) After review of the respective positions provided by Appellants and the Examiner, we AFFIRM for the reasons presented by the Examiner and add the following for emphasis. We refer to the Examiner's Final Action for a statement of the rejection. Final Act. 5-9. Appellants argue Minamihaba is directed to polishing of metal films such as copper. App. Br. 7. Thus, Appellants assert one skilled in the art would not have relied upon the Minamihaba teachings regarding removal of metals such as copper when contemplating a method for selectively removing silicon carbide as compared to silicon oxide absent impermissible hindsight. App. Br. 8. We are unpersuaded by Appellants' arguments. The Examiner found Minamihaba discloses a polishing slurry comprising colloidal silica abrasives for polishing a silicon carbide series compound film formed over a 5 Appeal2015-001626 Application I2/630,288 silicon dioxide film to selectively remove the silicon carbide series compound film with respect to the silicon dioxide film. Ans. I I; Minamihaba Abstract, Figures IA-IC, i-fi-f I0-11, 2I, 52, 66. Appellants' arguments do not address this finding by the Examiner. Thus, Appellants' arguments do not point to error in the Examiner's determination of obviousness. Appellants additionally argue that Minamihaba's CMP composition is not the same as the claimed CMP composition because Minamihaba teaches aggregation of the abrasive is desirable as it improves the polishing rate. App. Br. 8; Minamihaba i148. We also find this argument unavailing for the reasons presented by the Examiner. Ans. I I. A review of the cited art indicates both references focus on providing the colloidal silica abrasive in a stable dispersion for use in the CMP process. Minamihaba i-fi-134, 37, 47; Belov i-f IO. Moreover, paragraph 48 of Minamihaba suggests the aggregate is formed to ensure the effectiveness of the colloidal silica as an abrasive. Therefore we agree with the Examiner's determination that the ionically formed aggregate of Minamihaba is different from the agglomeration issue alleged by Appellants and addressed by Belov (emphasis added). Ans. I I; Minamihaba i-f 48; Belov i-f IO. Appellants' argument again does not adequately explain error in the Examiner's determination. Accordingly, we affirm the Examiner's prior art rejection of claims I- 3, 6, 7, IO, I2-I6, I8, 20-23, 26, 27, 29-3 I, and 33 for the reasons presented by the Examiner and given above. 6 Appeal2015-001626 Application 12/630,288 Rejection III (claim 9) We AFFIRM. Dependent claim 9 requires the use an acidic buffering agent comprising a phosphoric acid. The Examiner found that the combined teachings of Desai and Belov disclose the use of phosphonic acid an acidic buffering agent but do not disclose the use of a phosphoric acid. Final Act. 9; Desai i-f 21. The Examiner found Takemiya teaches phosphoric acid and phosphonic acid as rate adjusting agents for a CMP composition used to polish silicon carbide. Final Act. 9; Takemiya i-fi-121, 60. The Examiner determined it would have been obvious to one of ordinary skill in the art to use phosphoric acid as an equivalent substitution for phosphonic acid in the CMP composition and method of the combined teachings in view of Takemiya's disclosure. Final Act. 9-10. Appellants argue there would be no expectation of success in using phosphoric acid in the CMP composition of Desai because Takemiya teaches a high pH when using phosphoric acid as the rate adjusting compound. App. Br. 9; Takemiya i-f 21. We are unpersuaded by this argument. Given that Takemiya discloses phosphoric acid and the phosphonic acid of Desai are known removal rate adjusting agents for CMP compositions (Takemiya i-f 21 ), Appellants have not adequately explained why one skilled in the art would not have used phosphoric acid as a removal rate adjusting agent in CMP compositions having lower pH values than the ones disclosed by Takemiya. Appellants have not adequately explained why one skilled in the art would not have been capable of determining the appropriate amount of phosphoric acid to 7 Appeal2015-001626 Application 12/630,288 ensure that the Desai' s CMP compositions would achieve the desired silicon carbide removal rate. See In re Sovish, 769 F.2d 738, 743 (Fed. Cir. 1985) (skill is presumed on the part of one of ordinary skill in the art); In re Bozek, 416 F.2d 1385, 1390 (CCPA 1969). Accordingly, we affirm the Examiner's prior art rejection of claim 9 for the reasons presented by the Examiner and given above. ORDER The Examiner's prior art rejections of claims 1-10, 12-16, 18, 20-27, 29-31, and 33 are affirmed. TIME PERIOD No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. Â§ 1.136(a)(l). AFFIRMED 8