Ex Parte Ellmer et alDownload PDFPatent Trial and Appeal BoardSep 30, 201412516713 (P.T.A.B. Sep. 30, 2014) Copy Citation UNITED STATES PATENT AND TRADEMARK OFFICE _________ BEFORE THE PATENT TRIAL AND APPEAL BOARD __________ Ex parte KLAUS ELLMER and THOMAS UNOLD __________ Appeal 2013-002047 Application 12/516,713 Technology Center 1700 ___________ Before ADRIENE LEPIANE HANLON, KAREN M. HASTINGS, and MICHAEL P. COLAIANNI, Administrative Patent Judges. HANLON, Administrative Patent Judge. DECISION ON APPEAL A. STATEMENT OF THE CASE The Appellants appeal under 35 U.S.C. § 134 from a final rejection of claims 8–15, which are all of the pending claims. We have jurisdiction under 35 U.S.C. § 6(b). We AFFIRM. Claim 8 is representative of the subject matter on appeal and is reproduced below from the Claims Appendix of the Appeal Brief dated June 22, 2012 (“Br.”). 8. A method of reactive magnetron sputtering for deposition of a chalcopyrite absorber layer for thin-film solar cells on a substrate, using at least one magnetron sputter source with at least one copper Appeal 2013-002047 Application 12/516,713 2 target, and using an inert gas and a chalcogen-containing reactive gas in a magnetron plasma, the method comprising: introducing the chalcogen-containing reactive gas directly at the substrate; setting the chalcogen-containing reactive gas fraction at 5 to 30% of the inert gas fraction in the magnetron plasma; setting a sputtering pressure of between 1 and 2 Pa; applying a negative bias voltage to the substrate during the reactive magnetron sputtering; exciting the magnetron plasma by radio frequency AC voltage above 6 MHz; heating the substrate to a temperature between 350 ºC and 500 ºC; and performing a copper-poor deposition by disposing different targets, serial in time, in the at least one magnetron sputter source and operating the targets at the same sputtering power, or by disposing same targets, parallel in time, in the at least one magnetron sputter source and operating the targets at different sputtering powers, so as to obtain stoichiometry gradients. The claims on appeal stand rejected as follows: (1) claims 8–12 under 35 U.S.C. § 103(a) as unpatentable over Unold1 in view of Shao,2 Kondo,3 and Hollars;4 (2) claim 13 under 35 U.S.C. § 103(a) as unpatentable over Unold in 1 Thomas Unold et al., Reactive Magnetron Sputtering of CuInS2 Solar Cells – The Influence of the Deposition Conditions on Structural and Electronic Properties and Solar Cell Efficiency, 15th International Photovoltaic Science & Engineering Conference 503-04 (2005). 2 Lexi Shao et al., The one-step vacuum growth of high-quality CuInS2 thin film suitable for photovoltaic applications, 6 MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING 397-400 (2003). 3 Ken-ichi Kondo et al., Growth and Characterization of CuInS2 Films grown by Rf Ion-Plating, 36 JPN. J. APPL. PHYS. 6668-71 (1997). 4 US 6,974,976 B2, issued December 13, 2005. Appeal 2013-002047 Application 12/516,713 3 view of Shao, Kondo, Hollars, and Thornton;5 (3) claim 14 under 35 U.S.C. § 103(a) as unpatentable over Unold in view of Shao, Kondo, Hollars, and Chapin;6 and (4) claim 15 under 35 U.S.C. § 103(a) as unpatentable over Unold in view of Shao, Kondo, Hollars, Chapin, and Takahashi.7 As to rejection (1), the Appellants do not argue the patentability of claims 8– 12 as a group. Therefore, for purposes of this appeal, claims 9–12 stand or fall with the patentability of claim 8. As for the remaining rejections on appeal, the Appellants do not present arguments in support of the separate patentability of any of the claims subject to rejections (2)–(4). See Br. 6. Therefore, the patentability of claims 13, 14, and 15 will be considered based on the arguments set forth in support of the patentability of claim 8. B. DISCUSSION The Examiner finds that Unold discloses a method of reactive magnetron sputtering for large area deposition of a chalcopyrite absorber layer for thin film solar cells on a substrate. The Examiner finds the disclosed method uses at least one magnetron sputter source with at least one copper target as well as an inert gas and a chalcogen-containing reactive gas in a magnetron plasma. The Examiner finds the method includes the steps of introducing the chalcogen-containing reactive gas directly at the substrate; setting a sputtering pressure of between 1 and 2 Pa; and heating the substrate to a temperature between 350 and 500 degrees C as recited in claim 8. Ans. 5.8 5 John A. Thornton & T.C. Lommasson, Magnetron Reactive Sputtering of Copper–Indium–Selenide, 16 SOLAR CELLS 165-80 (1986). 6 US 4,166,784, issued September 4, 1979. 7 US 2007/0123004 A1, published May 31, 2007. 8 Examiner’s Answer dated August 24, 2012. Appeal 2013-002047 Application 12/516,713 4 The Examiner relies on Shao, Kondo, and Hollars to teach the remaining steps recited in claim 8. In particular, the Examiner finds that Shao teaches using a chalcogen-containing reactive gas fraction at 30% of the inert gas fraction in the magnetron plasma and exciting the magnetron plasma by radio frequency AC voltage greater than about 6 MHz. Id. at 6. The Examiner finds that Kondo teaches applying a negative bias during physical vapor deposition to control the surface morphology and crystallinity of the film. Id. The Examiner finds that Hollars teaches performing low copper deposition by disposing different targets serial in time. Id. at 7. The Appellants argue that Unold describes a reactive magnetron sputtering process which avoids a large copper ratio. The Appellants argue that Shao, on the other hand, discloses a process “in which ‘[a]ll films are Cu-rich.’” Br. 4 (quoting Shao 398). Thus, the Appellants argue that one of ordinary skill in the art “would not look to [the process of Shao] which only produces copper-rich layers to modify a process in which excess copper should be avoided.” Br. 4. The Appellants also argue that the Examiner’s reason for selecting the parameters from Shao is “faulty.” Id. According to the Appellants, “the motivation for ‘setting the chalcogen-containing reactive gas fraction at 5 to 30% of the inert gas fraction in the magnetron plasma’ and ‘exciting the magnetron plasma by radio frequency AC voltage above 6 MHz’ is that ‘it allows for controlling the atomic ratio of the film.’” Id. (citing Final 4–59). However, the Appellants argue that Shao does not suggest using a chalcogen-containing reactive gas in any range below 30%. Id. As for the excitation frequency, the Appellants 9 Final Office Action dated February 28, 2012. Appeal 2013-002047 Application 12/516,713 5 argue that Shao does not disclose or suggest that the excitation frequency has any bearing on atomic ratio. Id. at 5. In response, the Examiner finds that Unold produces a copper-poor deposition using 33% reactive gas. The Examiner finds that “[s]ince the 33% teaching of Unold is close enough to Appellants 30% it is believed to produce a film having the same properties as Appellants (i.e. a copper[-]poor film).” Ans. 11 (citing Titanium Metals Corp. of Am. v. Banner, 778 F.2d 775 (Fed. Cir. 1985)). The Appellants do not direct us to any evidence to the contrary. As for the excitation frequency recited in claim 8, the Examiner points out that Shao teaches the excitation frequency to be 13.4 MHz. Ans. 16. The Examiner also directs our attention to Hollars. Hollars discloses a process for depositing a copper-poor coating for a solar cell using a reactive magnetron sputtering process.10 The Examiner finds, and the Appellants do not dispute, that Hollars teaches that the composition of the deposited copper deficient coating is dependent on many factors, including sputtering pressure and sputtering power. Id. at 12; see also Hollars, col. 14, ll. 25–27, 36–41. Thus, one of ordinary skill in the art would have understood that sputtering parameters, including excitation frequency, are result-effective variables. See In re Boesch, 617 F.2d 272, 276 (CCPA 1980) (“discovery of an optimum value of a result effective variable in a known process is ordinarily within the skill of the art”). As for the remaining limitations recited in claim 8 that are not disclosed in Unold, the Examiner makes specific findings of fact based on the teachings of 10 Hollars discloses that the coating may be deposited using conventional planar magnetrons or cylindrical rotary magnetrons. See, e.g., Hollars, col. 13, ll. 55-57; id. at col. 15, ll. 3-6. Hollars also discloses that AC reactive sputtering is an alternative to DC sputtering. See, e.g., Hollars, col. 15, ll. 41-44. Appeal 2013-002047 Application 12/516,713 6 Kondo and Hollars and specific conclusions of law based on the combined teachings of Unold, Kondo, and/or Hollars. See Ans. 6–8. The Appellants do not direct us to any error in those factual findings or legal conclusions. Rather, the Appellants generally argue that “the processes of Kondo (rf ion-plating, see abstract) and Hollars (roll-to-roll vacuum deposition, see col. 1, lines 9–15) are materially different from the reactive magnetron sputtering of Unold.” Br. 5. For this reason, the Appellants contend that the combination of Unold with Kondo and Hollars is improper. Id. The mere fact that the processes disclosed in Kondo and Hollars may be different from the process disclosed in Unold is not persuasive of reversible error. The Examiner finds, and the Appellants do not dispute, that Unold, Kondo, and Hollars disclose physical vapor deposition processes. Ans. 16. Thus, absent any evidence or technical reasoning to the contrary, one of ordinary skill in the art would have found the teachings of Kondo and Hollars relevant to the process disclosed in Unold. Finally, the Appellants argue that the claimed method provides surprising and unexpected results. The Appellants rely on paragraphs 11, 14, 15, and 25 of the original Specification for support. Br. 3–4, 5. Significantly, the portions of the Specification relied on by the Appellants do not disclose comparative test data but rather contain conclusory statements relating to the disclosed method. “It is well settled that unexpected results must be established by factual evidence. Mere argument or conclusory statements in the specification does not suffice.” In re De Blauwe, 736 F.2d 699, 705 (Fed. Cir. 1984); see also Ans. 11. For the reasons set forth above and in the Examiner’s Answer, the § 103(a) rejections are sustained. Appeal 2013-002047 Application 12/516,713 7 C. DECISION The decision of the Examiner is affirmed. 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). AFFIRMED cdc Copy with citationCopy as parenthetical citation