APPLIED MATERIALS, INC.Download PDFPatent Trials and Appeals BoardOct 8, 20212020005389 (P.T.A.B. Oct. 8, 2021) Copy Citation 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. 15/426,102 02/07/2017 XIAODONG WANG 24741USA 1098 55649 7590 10/08/2021 Moser Taboada / Applied Materials, Inc. 1030 Broad Street Suite 203 Shrewsbury, NJ 07702 EXAMINER BAND, MICHAEL A ART UNIT PAPER NUMBER 1794 NOTIFICATION DATE DELIVERY MODE 10/08/2021 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 ataboada@mtiplaw.com docketing@mtiplaw.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE PATENT TRIAL AND APPEAL BOARD ____________ Ex parte XIAODONG WANG, RONGJUN WANG, and HANBING WU1 ____________ Appeal 2020-005389 Application 15/426,102 Technology Center 1700 ____________ Before CATHERINE Q. TIMM, CHRISTOPHER C. KENNEDY, and SHELDON M. MCGEE, Administrative Patent Judges. KENNEDY, Administrative Patent Judge. DECISION ON APPEAL This is an appeal under 35 U.S.C. § 134(a) from the Examiner’s decision rejecting claims 1–12. We have jurisdiction under 35 U.S.C. § 6(b). We AFFIRM. BACKGROUND The subject matter on appeal relates to semiconductor manufacturing, and, more specifically, to methods for performing pasting in a deposition chamber. See, e.g., Spec. ¶ 1; Claim 1. The Specification discloses that 1 We use the word “Appellant” to refer to “applicant” as defined in 37 C.F.R. § 1.42. The Appellant identifies the real party in interest as Applied Materials, Inc. Appeal Br. 3. Appeal 2020-005389 Application 15/426,102 2 sputtering processes may “undesirably result[] in producing a layer of the source material on the inner structure of a process chamber.” Spec. ¶ 2. “The unwanted coating of the inner structure . . . may cause defects and contamination in subsequent wafer processing.” Id. ¶ 3. A “pasting” layer is said to encapsulate “material that has been inadvertently sputtered on the process chamber inner surfaces,” thereby reducing defects that might otherwise be caused by the unwanted coating. Id. ¶ 18. The Specification further discloses that “[t]he long term industry standard for the pasting layer material has been titanium (Ti) or a derived form of Ti,” and alleges that “the inventors have progressed to a new level of defect management in depositions by using tantalum (Ta) as a pasting layer . . . . Due to the high cost of Ta and Ta’s high reactance with oxygen, Ta was not previously considered as a viable target material for pasting.” Id. ¶ 30. Claim 1 is reproduced below from page 16 (Claims Appendix) of the Appeal Brief: 1. A method for performing pasting in a deposition chamber, comprising: depositing a tantalum (Ta) pasting layer over at least a portion of a first dielectric material layer, the first dielectric material layer formed by RF sputtering of a dielectric material target on at least an interior portion of the deposition chamber, the Ta pasting layer reducing particle defects caused by the first dielectric material layer. Appeal 2020-005389 Application 15/426,102 3 REJECTIONS ON APPEAL The claims stand rejected under 35 U.S.C. § 103 as follows: 1. Claims 1, 2, and 6 over Cao (US 2014/0110248 A1, published Apr. 24, 2014) and Ishibashi (US 6,365,009 B1, issued Apr. 2, 2002). 2. Claims 3–5 over Cao, Ishibashi, and Finley (JP 07197250A, dated Aug. 1, 1995) (translation of record). 3. Claim 7 over Cao, Ishibashi, and Lee (US 2015/0102461 A1, published Apr. 16, 2015). 4. Claim 8 over Cao, Ishibashi, and Kamijo (US 2016/0164490 A1, published June 9, 2016). 5. Claims 9–11 over Cao, Ishibashi, Finley, and Kamijo. 6. Claim 12 over Cao, Ishibashi, Finley, Kamijo, and Lee. ANALYSIS After review of the cited evidence in the appeal record and the opposing positions of the Appellant and the Examiner, we determine that the Appellant has not identified reversible error in the Examiner’s rejections. Accordingly, we affirm the rejections for reasons set forth below, in the Final Action dated August 2, 2019, and in the Examiner’s Answer. Rejections 1–4 The Appellant presents separate arguments for claims 1 and 2. We address those claims below. The remaining claims subject to Rejections 1–4 will stand or fall with claim 1, from which they depend. Claim 1. The Examiner finds that Cao teaches every element of claim 1, including the use of a tantalum pasting layer, except that Cao uses direct current (DC) to power its sputtering process rather than RF (radio Appeal 2020-005389 Application 15/426,102 4 frequency) as recited by claim 1. Final Act. 3. The Examiner finds that Ishibashi teaches that combining RF and DC power in a sputtering process “stop[s] production of tracking arcs and promote[s] consistent manufacture of thin films.” Id. at 4. The Examiner finds that it would have been obvious to “add a[n] RF power supply as taught by Ishibashi to the DC power supply . . . of Cao to gain the advantages of stopping production of tracking arcs and promoting consistent manufacture of thin films.” Id. The Appellant first argues that Ishibashi teaches that “combination RF-DC power supplies create tracking arc issues which impact the quality of the film deposition,” as allegedly evidenced by certain working examples of Ishibashi in which RF power is periodically stopped or reducing (while DC power is maintained) during deposition. Appeal Br. 6. In view of that, the Appellant argues that “it is not logical” to modify Cao as proposed by the Examiner. Id. That argument is not persuasive for reasons stated by the Examiner. Ans. 3–4. The record establishes that use of RF, DC, and RF+DC power in sputtering processes was well known in the art, and that each was known to have certain advantages and disadvantages. See, e.g., Ishibashi at 1:14–2:3; Spec. ¶ 4 (“Background”). Ishibashi describes both RF and DC processes, and then goes on to describe a method that simultaneously uses both RF and DC power to yield a deposition that “stops the production of tracking arcs and promotes the consistent manufacture of thin films.” Ishibashi at Abstr., 1:14–61, 3:52–63. Consistent with the Examiner’s analysis, a person of ordinary skill in the art reasonably would have viewed Ishibashi’s RF+DC method as having certain benefits over RF or DC power alone, and therefore would have had reason to modify Cao as proposed by the Examiner. See Appeal 2020-005389 Application 15/426,102 5 Ishibashi at Abstr., 1:14–61, 3:52–63. A person of ordinary skill in the art would also have viewed RF, DC, and RF+DC as known alternatives to each other, each having certain advantages and disadvantages. See, e.g., Winner Int’l Royalty Corp. v. Wang, 202 F.3d 1340, 1349 n.8 (Fed. Cir. 2000) (“The fact that the motivating benefit comes at the expense of another benefit . . . should not nullify its use as a basis to modify the disclosure of one reference with the teachings of another. Instead, the benefits, both lost and gained, should be weighed against one another.”). In that regard, we observe that the Appellant does not allege that the inventors discovered something new about the use of RF or DC power during sputtering processes; rather, the Specification alleges that the inventive discoveries relate to the use of tantalum, rather than titanium, as a pasting material. See Spec. ¶ 30. Cao predates the application on appeal by several years and unequivocally discloses that tantalum is a suitable pasting material in sputtering processes. Cao ¶ 52. On this record, we are not persuaded of reversible error in the Examiner’s rejection of claim 1. Claim 2. Claim 2 depends from claim 1 and recites that the method further comprises “depositing a second dielectric material layer by RF sputtering a dielectric material target on at least a portion of the Ta pasting layer.” Appeal Br. 16 (Claims Appendix). We understand that recitation to indicate that the sputtering process is simply repeated, e.g., performed on consecutive substrates, such that the Ta pasting layer on the chamber walls (formed after the first iteration) becomes at least partially covered by sputtered dielectric material on a second iteration. Appeal 2020-005389 Application 15/426,102 6 The Examiner finds that Cao teaches or suggests this limitation because Cao discloses at paragraph 46 that “a plurality of substrates may be processed consecutively.” Final Act. 4. The Appellant argues that “[p]resuming or considering that a method is repeated to form a second dielectric layer . . . is not factual evidence that the second dielectric material layer method is taught by Cao or Ishibashi.” Appeal Br. 7. That argument is not persuasive. The Examiner does not “presum[e] or consider[]” that Cao’s method is repeated; as set forth above, Cao expressly teaches that at paragraph 46. As to whether the repetition would result in additional sputtering on the chamber walls of dielectric material, there is no dispute that such occurs during Cao’s first iteration, and the Appellant provides no reason whatsoever to believe that it would not likewise occur during subsequent iterations. See, e.g., Cao ¶ 49 (“During deposition, some dielectric material may be formed on inner surfaces 150 of the physical vapor deposition chamber.”). On this record, we are not persuaded of reversible error in the Examiner’s rejection of claim 2. Rejections 5 and 6 The Appellant presents arguments only as to claims 9 and 12. We address those claims below, and the remaining claims subject to Rejections 5 and 6 will stand or fall with claim 9, from which they depend. Claim 9. Independent claim 9 is similar to claim 1, but, of particular relevance to the arguments raised by the Appellant, further requires “flowing oxygen into the RF PVD chamber to bond with the Ta pasting layer.” Appeal Br. 17 (Claims Appendix). Appeal 2020-005389 Application 15/426,102 7 The Examiner relies on Cao and Ishibashi as set forth above, and further finds that Finley teaches that supplying oxygen gas over a Ta layer yields “a hard metal film excellent in durability and chemical resistance.” Final Act. 9. The Examiner finds that it would have been obvious to flow oxygen over the Ta pasting layer of Cao to improve the layer’s durability and chemical resistance. Id. The Appellant first repeats the arguments discussed above concerning Cao and Ishibashi. Appeal Br. 11–12. Those arguments are unpersuasive for reasons set forth above. As to the Examiner’s reliance on Finley, the Appellant argues that, “contrary to the Examiner’s assertion . . . Finley actually teaches to thermally oxidize the metal film.” Appeal Br. 12–13. The Appellant does not dispute the Examiner’s finding that a person of ordinary skill in the art would have understood from Finley that flowing oxygen over a Ta layer increases its durability and chemical resistance. Nor does the Appellant dispute that such would have been desirable in Cao’s Ta pasting layer. The Appellant’s limited argument fails to identify reversible error in the Examiner’s rationale. Claim 12. Claim 12 depends from claim 9 and further recites, “depositing the Ta pasting layer to an approximate thickness of 10 Å.” Appeal Br. 18 (Claims Appendix). The Examiner finds that Lee teaches a semiconductor structure in which a barrier layer of Ta is deposited over a dielectric layer, and that Lee’s barrier layer has a thickness of 5–10 Å. Final Act. 11. The Examiner finds that it would have been obvious to use a thickness taught by Lee with the Ta pasting layer of Cao because Cao “fails to specify a particular thickness, and Appeal 2020-005389 Application 15/426,102 8 one of ordinary skill would have a reasonable expectation for success in making the modification since Lee teaches that the Ta is a barrier layer material over a dielectric material, similar to how [Cao] utilizes the Ta pasting layer as barrier over the first dielectric material layer to prevent negative effects.” Id. The Appellant argues that the Examiner has not established a reason to use the thickness of Lee’s barrier layer because Cao’s “tantalum pasting layer is not a barrier layer as used in Lee.” Appeal Br. 14. The Appellant argues that the purpose of Lee’s barrier layer is to “prevent[] subsequently deposited conductive materials from migrating into a dielectric layer,” which is not the same as the purpose of Cao’s tantalum layer. Id. That argument is not persuasive. Even accepting that the purpose of Lee’s tantalum layer is not identical to that of Cao’s tantalum layer, there is no meaningful dispute that both the tantalum layer of Cao and the tantalum layer of Lee serve as barriers atop dielectric layers in sputtering processes. Cao suggests that one purpose of its tantalum layer is to maintain consistent electrical properties (e.g., circuit impedance and voltage distribution). See Cao ¶ 7. Cao does not specify a thickness for its barrier layer, so it is reasonable to believe that a person of ordinary skill in the art would have looked to other references using tantalum barrier layers for guidance. There is no dispute that Lee teaches a tantalum layer thickness of 5–10 Å to protect an underlying dielectric material during a sputtering process, and to maintain electrical properties of that layer (e.g., by preventing conductive materials from migrating into the dielectric layer, as the Appellant acknowledges). That provides adequate motivation to use a thickness of 10 Å in the process of Cao, and a reasonable expectation that such a thickness would adequately Appeal 2020-005389 Application 15/426,102 9 protect the underlying dielectric material. Although a person of ordinary skill in the art may not have had absolute certainty that 10 Å would be adequate in Cao because the purpose of Cao’s tantalum barrier layer is not identical to that of Lee, certainty of success is not required to establish obviousness. See PAR Pharm., Inc. v. TWI Pharm., Inc., 773 F.3d 1186, 1198 (Fed. Cir. 2014) (“The reasonable expectation of success requirement for obviousness does not necessitate an absolute certainty for success.”). We affirm the Examiner’s rejection of claim 12. CONCLUSION In summary: Claim(s) Rejected 35 U.S.C. § References Affirmed Reversed 1, 2, 6 103 Cao, Ishibashi 1, 2, 6 3–5 103 Cao, Ishibashi, Finley 3–5 7 103 Cao, Ishibashi, Lee 7 8 103 Cao, Ishibashi, Kamijo 8 9–11 103 Cao, Ishibashi, Finley, Kamijo 9–11 12 103 Cao, Ishibashi, Finley, Kamijo, Lee 12 Overall Outcome 1–12 No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a). AFFIRMED Copy with citationCopy as parenthetical citation