Applied Materials, Inc.

Patent Trials and Appeals Board

Mar 25, 2022

2021001499 (P.T.A.B. Mar. 25, 2022)

UNITED STATES PATENT AND TRADEMARK OFFICE 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 APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO. 15/598,687 05/18/2017 Sang-Ho YU 012196USC02 1014 44257 7590 03/25/2022 PATTERSON & SHERIDAN, LLP - - APPLIED MATERIALS 24 GREENWAY PLAZA SUITE 1600 HOUSTON, TX 77046 EXAMINER PADGETT, MARIANNE L ART UNIT PAPER NUMBER 1717 NOTIFICATION DATE DELIVERY MODE 03/25/2022 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): Applied_Materials.Pair@anaqua.com Pair_Eofficeaction@pattersonsheridan.com psdocketing@pattersonsheridan.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE PATENT TRIAL AND APPEAL BOARD ____________ Ex parte SANG-HO YU, KEVIN MORAES, SESHADRI GANGULI, HUA CHUNG, and SEE-ENG PHAN ____________ Appeal 2021-001499 Application 15/598,687 Technology Center 1700 ____________ Before TERRY J. OWENS, JEFFREY R. SNAY, and BRIAN D. RANGE, Administrative Patent Judges. SNAY, Administrative Patent Judge. DECISION ON APPEAL STATEMENT OF THE CASE Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the Examiner’s decision to reject claims 1-12 and 15-22. We have jurisdiction under 35 U.S.C. § 6(b). We AFFIRM. 1 “Appellant” refers to “applicant” as defined in 37 C.F.R. § 1.42. Appellant identifies Applied Materials, Inc., as the real party in interest. Appeal Br. 3. Appeal 2021-001499 Application 15/598,687 2 BACKGROUND The invention relates to a metallization process for manufacturing semiconductor devices. Spec. ¶ 1. Claim 1 reads as follows: 1. A method for capping a copper surface on a substrate, comprising: positioning a substrate within a processing chamber, wherein the substrate comprises a copper oxide surface and a dielectric surface; exposing the copper oxide surface to a first reducing agent to form a metallic copper surface during a pre-treatment process, wherein the metallic copper surface and the dielectric surface are coplanar; selectively forming a cobalt capping layer on the metallic copper surface while leaving exposed the dielectric surface, comprising: exposing the substrate to a cobalt precursor gas to form a sublayer of the cobalt capping layer during a vapor deposition process; exposing the sublayer of the cobalt capping layer to a first plasma during a post-treatment process, and repeating the vapor deposition process and the post- treatment process a plurality of times to deposit additional sublayers to form the cobalt capping layer; and depositing a dielectric layer on the cobalt capping layer and the dielectric surface. Appeal Br. 11 (Claims Appendix). Claims 12 and 21 recite methods which are similar to that of claim 1, and include the same disputed recitations. Each remaining claim on appeal depends from claim 1, 12, or 21. Appeal 2021-001499 Application 15/598,687 3 REJECTIONS I. Claims 1-12 and 15-22 stand rejected under 35 U.S.C. § 103(a) as unpatentable over Shih,2 Dordi,3 Kostamo,4 Ganguli,5 Chang,6 Ma,7 Banerji,8 and Chung.9 II. Claims 1-12 and 15-22 stand rejected on the ground of nonstatutory double patenting over Ai10 in view of Shih, Ganguli, Kostamo, Ma, Chung, and Dordi. III. Claims 1-12 and 15-22 stand rejected on the ground of nonstatutory double patenting over Ren ‘44811 in view of Shih, Ganguli, Kostamo, Ma, Chung, and Dordi. IV. Claims 1-12 and 15-22 stand rejected on the ground of nonstatutory double patenting over Ren ‘43112 in view of Shih, Ganguli, Kostamo, Ma, Chung, and Dordi. V. Claims 1-12 and 15-22 stand rejected on the ground of nonstatutory double patenting over Wu13 in view of Shih, Ganguli, Kostamo, Ma, Chung, and Dordi. 2 US 2007/0048991 A1, published March 1, 2007. 3 US 2007/0292615 A1, published December 20, 2007. 4 US 2005/0208754 A1, published September 22, 2005. 5 US 2004/0241321 A1, published December 2, 2004. 6 US 2005/0220988 A1, published October 6, 2005. 7 US 2007/0119370 A1, published May 31, 2007. 8 US 7,648,899 B1, issued January 19, 2010. 9 US 2006/0199372 A1, published September 7, 2006. 10 US 10,043,709, issued August 7, 2018. 11 US 10,008,448 B2, issued June 26, 2018. 12 US 9,601,431 B2, issued March 21, 2017. 13 US 10,395,916 B2, issued August 27, 2019. Appeal 2021-001499 Application 15/598,687 4 VI. Claims 1-12 and 15-22 stand provisionally rejected on the ground of nonstatutory double patenting over Ye14 in view of Ma, Ganguli, and Kostamo. OPINION Obviousness Each independent claim on appeal recites, inter alia, positioning a substrate having copper oxide and dielectric surfaces, and exposing the copper oxide surface to an agent to form a metallic copper surface that is coplanar relative to the dielectric surface. See claims 1, 12, 21. Claims 1 and 12 specify using a reducing agent and claim 21 specifies using a plasma for performing the above-mentioned exposure step. In rejecting Appellant’s claims, the Examiner finds Shih discloses a method for capping a copper surface on a substrate, but fails to teach forming the copper surface by exposure of copper oxide to either a reducing agent or plasma, and further fails to teach metallic copper and dielectric surfaces that are coplanar. Final Act. 5-7, 17. The Examiner’s obviousness determination as to each independent claim is premised on a finding that Dordi would have provided one of ordinary skill in the art with a reason to modify Shih such that the metallic copper surface to be capped was coplanar with the dielectric surface. Id. at 7. The Examiner’s obviousness determination is further premised on a finding that Kostamo would have provided one of ordinary skill in the art with a reason to contact Shih’s metallic copper surface with reducing agent or plasma prior to capping, “to 14 US Application Serial No. 15/800,784, published May 24, 2018 as US 2018/0144973 A1. Appeal 2021-001499 Application 15/598,687 5 ensure copper surfaces have been appropriately cleaned . . . to effect a metallic surface free of contaminants or residues that would inhibit the required reactions for selective Co deposition.” Id. at 17. Appellant argues both these foundational findings are in error. Appeal Br. 7-9. Particularly, Appellant argues Shih requires the metallic copper surface to be recessed relative to the dielectric surface prior to capping, and the Examiner has not provided a reason why one skilled in the art would have applied Dordi to alter Shih’s disclosed technique to involve coplanar metal and dielectric surfaces. Id. at 8. Appellant also argues neither Kostamo nor any other relied-upon reference would have provided a reason to further modify Shih to form the metallic copper surface by contacting copper oxide with a reducing agent or plasma. Id. at 9. Shih discloses forming a conductive cap over a copper recess. Shih ¶ 16. In fact, Shih teaches forming the copper surface to be capped by: (1) overfilling a via or trench; (2) removing overfilled copper by a chemical mechanical polishing (CMP) until the copper surface and surrounding barrier layer are substantially coplanar; and then (3) forming a recessed copper surface through another CMP process. Shih ¶¶ 12-16. According to Shih, a cobalt-containing cap is then formed over the copper surface, “within the recess.” Id. ¶ 16. Preferably, “the surface of the conductive cap 54 is substantially the same as the surrounded dielectric layer 30.” Id. The Examiner finds Dordi teaches capping a copper surface that is coplanar with a dielectric surface, and therefore “makes it clear that it was previously known in the prior art to employ selective growth of a capping layer that could be Co without a recess.” Final Act. 5-6. The Examiner concludes, “[t]herefore these combined teachings would have reasonably Appeal 2021-001499 Application 15/598,687 6 suggested to one of ordinary skill in the art that Co deposition on either slightly recessed or co-planar configurations were known.” Id. at 8. It is well-established that “rejections on obviousness grounds cannot be sustained by mere conclusory statements; instead, there must be some articulated reasoning with some rational underpinning to support the legal conclusion of obviousness.” In re Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006). We have reviewed the Final Action and the Examiner’s Answer and determine that the Examiner has not met the burden to articulate sufficient reasoning to support the legal conclusion of obviousness. For example, absent from the Examiner’s obviousness determination is a reason why one skilled in the art would have replaced Shih’s recessed copper surface, and resulting cobalt cap within the recess, with Dordi’s non-recessed metal and cap. The fact that a different configuration might exist is not itself sufficient evidence of substituting one for the other. The Examiner’s finding that Kostamo would have provided a reason to reduce metal oxides in Shih to form the copper surface also is without adequate evidentiary support. Shih teaches forming metallic copper through plating. Shih ¶ 12. As the Examiner acknowledges, Shih does not teach forming a metallic copper surface by exposing copper oxide to an agent. Nor does Shih mention copper oxides or any other materials being present on the copper surface to be capped. Nonetheless, the Examiner concludes “one of ordinary skill in the art would reasonably have look[ed] to the prior art for techniques to ensure copper surfaces have been appropriately cleaned . . . to effect a metallic surface free of contaminants or residues that would inhibit the required reactions for selective Co deposition (e.g. remove oxides).” Final Act. 17. The Examiner’s findings that Shih’s copper surface Appeal 2021-001499 Application 15/598,687 7 necessarily would have included copper oxides, and that such oxides would have necessitated treatment by a reducing agent, are not supported by evidence of record and, therefore, are conclusory and improper. See Kahn. Moreover, even if one were to accept that it would have been obvious to pre- treat Shih’s copper surface with reducing agent, that still would not address the recitation in claims 1, 12, and 21 that such treatment of copper oxide results in a metallic copper surface “wherein the metallic copper surface and the dielectric surface are coplanar.” The Examiner does not rely upon any other cited reference in a manner that would overcome the above-noted errors. For the foregoing reasons, the Examiner’s obviousness rejection is not sustained. Nonstatutory Double Patenting Appellant presents no argument addressing any of the Examiner’s rejections or provisional rejections on the ground of nonstatutory double patenting. Accordingly, each of the double patenting rejections is summarily sustained. CONCLUSION The Examiner’s decision rejecting claims 1-12 and 15-22 is affirmed. Appeal 2021-001499 Application 15/598,687 8 DECISION SUMMARY In summary: Claim(s) Rejected 35 U.S.C. § References/Basis Affirmed Reversed 1-12, 15- 22 103(a) Shih, Dordi, Kostamo, Ganguli, Chang, Ma, Banerji, Chung 1-12, 15- 22 1-12, 15- 22 Ai, Shih, Ganguli, Kostamo, Ma, Chung, Dordi 1-12, 15- 22 1-12, 15- 22 Ren ‘448, Shih, Ganguli, Kostamo, Ma, Chung, Dordi 1-12, 15- 22 1-12, 15- 22 Ren ‘431, Shih, Ganguli, Kostamo, Ma, Chung, Dordi 1-12, 15- 22 1-12, 15- 22 Wu, Shih, Ganguli, Kostamo, Ma, Chung, Dordi 1-12, 15- 22 1-12, 15- 22 Ye, Ma, Ganguli, Kostamo 1-12, 15- 22 Overall outcome 1-12, 15- 22 No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv). AFFIRMED