Ex Parte Meiere

Patent Trial and Appeal BoardNov 16, 2012

11063638 (P.T.A.B. Nov. 16, 2012)

UNITED STATES PATENT AND TRADEMARKOFFICE 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. 11/063,638 02/24/2005 Scott Houston Meiere 21394 7279 27182 7590 11/16/2012 PRAXAIR, INC. LAW DEPARTMENT - M1 557 39 OLD RIDGEBURY ROAD DANBURY, CT 06810-5113 EXAMINER HORNING, JOEL G ART UNIT PAPER NUMBER 1712 MAIL DATE DELIVERY MODE 11/16/2012 PAPER 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. PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE PATENT TRIAL AND APPEAL BOARD ____________ Ex parte SCOTT HOUSTON MEIERE ____________ Appeal 2011-011421 Application 11/063,638 Technology Center 1700 ____________ Before TERRY J. OWENS, ROMULO H. DELMENDO, and LINDA M. GAUDETTE, Administrative Patent Judges. GAUDETTE, Administrative Patent Judge. DECISION ON APPEAL Appellant appeals under 35 U.S.C. § 134(a) from the Examiner’s decision1 finally rejecting claims 1, 3-6, 8, 21, 23, and 27-32.2 We have jurisdiction under 35 U.S.C. § 6(b). We AFFIRM. The Examiner maintains the following grounds of rejection: 1. claims 1, 3-6, 8, 21, 23, and 27-32 are rejected under 35 U.S.C. §103(a) as unpatentable over McCord (US 3,293,005, issued Dec. 20, 1966) in view of Snyder (US 5,102,637, issued Apr. 7, 1992), further in view of Gutowski 1 Final Office Action mailed Aug. 10, 2010 2 Appeal Brief filed Jan. 10, 2011 (“Br.”) Appeal 2011-011421 Application 11/063,638 2 (Materials Research Society Symp. Proc., Vol. 716, B6.5.1- B6.5.6 (2002)) in view of Baum (US 6,869,638 B2, issued Mar. 22, 2005) in view of Zhuang (US 6,472,337 B1, issued Oct. 29, 2002) in view of Greenberg (US 3,069,232, issued Dec. 18, 1962) (Ans.3 8-11), or, in the alternative, under 35 U.S.C. §103(a) as unpatentable over McCord and Snyder alone (id. at 3-8); and 2. claims 8, 28, 29, and 32 are provisionally rejected on the ground of nonstatutory obviousness-type double patenting as unpatentable over claims 1 and 3-6 of copending US Application 11/245,104 (id. at 12-13). Of the appealed claims, claims 1, 8, 21, 27, and 28 are independent. Independent claims 1, 21, and 27 are method claims which recite “[a] process for producing a low zirconium hafnium halide composition useful for synthesis of a hafnium-containing precursor for chemical vapor or atomic layer film depositions in semiconductor applications.” Claims 8 and 28 are product-by-process claims which recite “[a] low zirconium hafnium halide composition useful for synthesis of a hafnium-containing precursor for chemical vapor or atomic layer film depositions in semiconductor applications.” With respect to the above-identified first ground of rejection, Appellants indicate the following two groups of claims are separately argued: (1) claims 1, 3- 6, 21, 23, 27, 30, and 31 (Br. 8-13 and 17-21), and (2) claims 8, 28, 29, and 32 (Br. 14-17 and 21-23). We decide the patentability of the separately argued groups of claims on the basis of independent claims 27 and 28, respectively. Claim 28 recites a composition produced by the same process recited in claim 27, which is reproduced below from the Claims Appendix to the Appeal Brief: 3 Examiner’s Answer mailed Apr. 15, 2011 Appeal 2011-011421 Application 11/063,638 3 27. A process for producing a low zirconium hafnium halide composition useful for synthesis of a hafnium-containing precursor for chemical vapor or atomic layer film depositions in semiconductor applications, said hafnium- containing precursor selected from the group consisting of an amide, alkoxide, diketonate, cyclopentadienide, and imide, said composition comprising a hafnium halide compound represented by the formula Hf(X)4 wherein X is the same or different and is a halide and wherein said composition has a zirconium concentration of less than about 500 parts per million, which process consists essentially of reacting a hafnium oxide compound, wherein said hafnium oxide compound has a zirconium concentration of less than about 500 parts per million, with a halogen or halogen-containing compound in the absence of air and moisture and under reaction conditions sufficient to produce said composition. According to Appellant, he has discovered that by “[s]tarting with high purity hafnium oxide, . . . hafnium halide compounds with low zirconium levels can be synthesized utilizing a single reaction. In contrast to methods existing prior to Appellants’ claimed invention, the hafnium halide compounds useful in this invention do not require fractional or multiple sublimation steps to obtain low zirconium levels.” (Br. 8.) The issue we consider with respect to the rejection of claims 1, 3-6, 8, 21, 23, and 27-32 under 35 U.S.C. §103(a) as unpatentable over McCord in view of Snyder, further in view of Gutowski in view of Baum in view of Zhuang in view of Greenberg is: did the Examiner reversibly err in finding one of ordinary skill in the art would have been motivated to use a high purity, i.e., low zirconium, HfO2 compound, in McCord’s method to produce a hafnium halide compound having a zirconium concentration of less than about 500 parts per million?4 4 We note that while Appellants present separate arguments in support of patentability of the above-noted claim groupings, the arguments raise the same issue. Appeal 2011-011421 Application 11/063,638 4 We answer this question in the negative for the reasons expressed in the Answer and below. A preponderance of the evidence of record supports the following findings of fact: McCord discloses a method of making HfCl4 by chlorinating hafnium oxide. (McCord, col. 1, ll. 11-13.) Zhuang, in turn, teaches a method of using HfCl4 to form a precursor for a thin film formed by CVD processes (Zhuang Abstract, col. 1, ll. 53-55), while Baum teaches a method of using a hafnium precursor to form a HfO2 film on a silicon substrate (Baum, col. 18, l. 44-col. 20, l. 10). In McCord’s method, reaction pellets are fed though a gas tight feeder with nitrogen to a gas tight reactor where chlorine gas is used as the reaction gas. (McCord, col. 5, ll. 63-75.) McCord discloses that the recovered product is anhydrous hafnium tetrachloride. (Id. at col. 1, ll. 15-16.) McCord discloses recovering a product which is a “high purity powder” (id. at col. 6, ll. 38-39), but does not teach that the HfCl4 product has a zirconium concentration of less than about 500 ppm. McCord teaches that [t]he use of substantially pure reactants together with stoichiometric amounts of reactants provides complete consumption of reactants and thereby eliminates the problems of residue removal from the chlorinator and impurities in the effluent gas. While the reactants need not be 100 percent pure, they must be relatively free of undesirable impurities. Therefore various impure oxidic ores containing substantial amounts of impurities may not be used in this invention, for the objects and advantages of this invention cannot be attained when such impure ores are used. (McCord col. 4, ll. 52-62.) McCord does not disclose that zirconium is an undesirable impurity in the hafnium tetrachloride product. (See Br. 9; cf. Ans. 9.) However, at the time of the Appeal 2011-011421 Application 11/063,638 5 invention, one of ordinary skill in the art would have been aware that “the presence of zirconia is undesirable in a hafnia film on silicon because it will make the interface less stable, which means that the presence of zirconium impurities in the hafnium precursor would also be undesirable, since it would be incorporated into the deposited hafnia film and decrease its stability.” (Ans. 9; see Gutowski B6.5.1. (“The zirconia/Si interface has been found to be unstable with respect to formation of silicides whereas the hafnia/Si interface is stable.”); cf. Br. 21 (“Gutowski . . . concerns a qualitative study which confirms the problem of zirconium in these compounds.” (citing the Declaration of Dr. Ronald Spohn, ¶ 11)).) At the time of the invention, one of ordinary skill in the art would have known that Hf and Zr metals “are normally associated together in nature” (Greenberg col. 1, ll. 15-17) , and that commercial methods were available by which HfO2 could be purified to levels of less than a few hundred ppm Zr. (Spec. [0008]; Br. 10.) Appellant acknowledges that “[a]t the time of [the] invention, chlorination of hafnium oxide and zirconium oxide on an industrial scale was known,” but maintains these processes resulted in a hafnium chloride product containing about 1-3% zirconium. (Br. 7.) Appellant argues that while highly pure material, i.e., having a zirconium content between 0.1-0.3%, could be obtained through tedious sublimation processes (id.), one of ordinary skill in the art would have had no motivation to produce such a product since “there was no recognition or appreciation in the semiconductor field of any problems resulting from zirconium impurities in hafnium halides and products made therefrom” (id.at 6). Appellant’s argument is unpersuasive given what we find to be a clear suggestion in Gutowski that the presence of zirconium would create instability in hafnium compositions used in semiconductor applications. (See Ans. 13-14.) Appellant has not refuted the Examiner’s finding that because the zirconium Appeal 2011-011421 Application 11/063,638 6 impurities in a dielectric material would come from the precursor material, it would have been obvious to make a precursor having a very low zirconium content. (See id. at 16.) Appellant argues McCord is not concerned with the manufacture of compounds for use in semiconductor processes and that use of an ultra-high purity hafnium oxide as recited in the appealed claims “would have been wasted on a set up like McCord that would produce material of much lower purity than that of the starting compound.” (Br. 9.) The facts and reasons relied on by the Examiner support findings that one of ordinary skill in the art would have recognized from McCord’s disclosure that the use of high purity reactants would provide a high purity product (see McCord col. 4, ll. 52-62 supra p. 4), and would have recognized from Gutowski that zirconium is an undesirable impurity in hafnium chloride compounds intended for use in semiconductor applications. (See Gutowski B6.5.1 supra p. 5; Spohn Declaration ¶ 11.) While McCord does not expressly disclose the use of HfCl4 for semiconductor applications, one of ordinary skill in the art would have understood that HfCl4 could be used to form a precursor for a dielectric film based on the disclosures of Zhuang and Baum. (See supra p. 4.) As such, one of ordinary skill in the art would have been motivated to use a low zirconium hafnium oxide as a reactant in McCord’s method where the resultant hafnium chloride product was intended for use in semiconductor applications, e.g., the synthesis of a hafnium- containing precursor for CVD depositions. As noted by the Examiner (see generally, Ans. 17-19), Appellant has not provided evidence which refutes a finding that McCord’s process, if modified to use a hafnium oxide compound having a zirconium concentration of less than 500 ppm, would result in a low zirconium hafnium halide composition as claimed. See In re Geisler, 116 F.3d Appeal 2011-011421 Application 11/063,638 7 1465, 1471 (Fed. Cir. 1997) (argument by counsel cannot take the place of evidence); In re Lindner, 457 F.2d 506, 508 (CCPA 1972) (mere conclusory statements of superiority in the Specification and/or the Brief, unsupported by factual evidence, are of little probative value). The Examiner has fully addressed any remaining arguments made by Appellant and not expressly discussed herein, convincingly explaining why such arguments are unpersuasive of error in the Examiner’s obviousness determination. (See generally, Ans. 13-22.)5 Accordingly, we affirm the rejection of claims 1, 3- 6, 8, 21, 23, and 27-32 under 35 U.S.C. §103(a) as unpatentable over McCord in view of Snyder, further in view of Gutowski in view of Baum in view of Zhuang in view of Greenberg. We do not reach the alternative rejection of these claims under 35 U.S.C. §103(a) as unpatentable over McCord in view of Snyder. Turning to the provisional rejection of claims 8, 28, 29, and 32 on the ground of nonstatutory obviousness-type double patenting, we note that Appellant does not raise substantive arguments traversing this rejection, but indicate they will take action to overcome the rejection upon allowance of the claims. (Br. 24.) Accordingly, we summarily affirm this ground of rejection. The Examiner’s decision to reject claims 1, 3-6, 8, 21, 23, and 27-32 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 cam 5 We note the Examiner has expressly considered the Spohn Declaration and explained why it fails to support a conclusion of nonobviousness. (See e.g., Ans. 21-22.)