Ex Parte Wang et alDownload PDFPatent Trial and Appeal BoardJun 26, 201511784076 (P.T.A.B. Jun. 26, 2015) 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. 11/784,076 04/05/2007 Hui-Chuan Wang HT06-044 4131 28112 7590 06/29/2015 SAILE ACKERMAN LLC 28 DAVIS AVENUE POUGHKEEPSIE, NY 12603 EXAMINER KIM, SUN M ART UNIT PAPER NUMBER 2813 MAIL DATE DELIVERY MODE 06/29/2015 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 HUI-CHUAN WANG, TONG ZHAO, MIN LI, and KUNLIANG ZHANG ____________ Appeal 2013-005578 Application 11/784,0761 Technology Center 2800 ____________ Before ADRIENE LEPIANE HANLON, CATHERINE Q. TIMM, and JAMES C. HOUSEL, Administrative Patent Judges. HOUSEL, Administrative Patent Judge. DECISION ON APPEAL Pursuant to 35 U.S.C. § 134, Appellants appeal from the Examiner’s decision rejecting claims 1 and 3–28 as unpatentable under 35 U.S.C. § 103(a). We have jurisdiction over the appeal under 35 U.S.C. § 6(b). We AFFIRM.2 1 According to Appellants, the Real Party in Interest is Headway Technologies Inc. App. Br. 3. 2 Our decision refers to Appellants’ Appeal Brief (Br.) filed September 24, 2012, the Examiner’s Answer (Ans.) mailed December 17, 2012, and Appellants’ Specification (Spec.). Appeal 2013-005578 Application 11/784,076 2 STATEMENT OF THE CASE The invention relates to magneto-resistance (MR) memory cells including a free layer made of multiple layers, such as FeCo and NiFe, wherein a surfactant layer is inserted within the free layer. Spec. 1, 3. Appellants disclose the surfactant layer may be of any of several known surfactant materials, such as oxygen or oxygen mixed with a nobel gas. Id. at 3. According to Appellants, placing the surfactant layer within the free layer reduces the impact of lattice mismatch between the NiFe and FeCo layers of the free layer. Id. at 4–5. Claims 1 and 17, reproduced below from the Claims Appendix to Appellants’ Brief, are illustrative of the subject matter on appeal: 1. A method to increase magneto-resistance of a magnetically free layer, comprising: providing a magnetic memory cell comprising a pinned layer on a pinning layer, a transition layer on said pinned layer, and said free layer on said transition layer, said free layer further comprising at least one layer containing cobalt and iron and at least one layer containing nickel and iron; and inserting, only within said free layer, a surfactant layer, formed using a gas mixture selected from the group consisting of oxygen mixed with argon, oxygen mixed with krypton, oxygen mixed with xenon, and oxygen mixed with neon, thereby improving performance of said free layer by reducing lattice strain within said free layer. 17. A magnetic memory cell, including a free layer that has reduced lattice strain, comprising: a magnetic pinning layer on a substrate; a magnetically pinned layer on said pinning layer; a transition layer on said pinned layer; a first ferromagnetic layer on said transition layer; Appeal 2013-005578 Application 11/784,076 3 a surfactant layer of oxygen on said first ferromagnetic layer and a second ferromagnetic layer on said surfactant layer; and said free layer that has reduced lattice strain comprising said surfactant layer sandwiched between said first and second ferromagnetic layers (sic; period missing) Independent claim 4, the only other independent process claim, recites, in pertinent part, a step of depositing a surfactant layer of oxygen and a noble gas on a first ferromagnetic layer, followed by a step of depositing a second ferromagnetic layer on the surfactant layer thereby sandwiching the surfactant layer between the first and second ferromagnetic layers. The Rejections Appellants request our review of the following rejections under 35 U.S.C. § 103(a) maintained by the Examiner: 1. Claims 1, 3–10, 15, and 16 as unpatentable over Pinarbasi3 in view of Horng A4 and Horng B;5 2. Claims 11–13 as unpatentable over the combination of Pinarbasi, Horng A, and Horng B, further in view of Diao;6 3. Claim 14 as unpatentable over the combination of Pinarbasi, Horng A, and Horng B, further in view of Sbiaa;7 4. Claims 17–22, 27, and 28 as unpatentable over Pinarbasi in view of Horng A; 5. Claims 23–25 as unpatentable over the combination of 3 US 6,907,655 B2, issued June 21, 2005. 4 US 6,993,827 B2, issued February 7, 2006. 5 US 7,201,827 B2, issued April 10, 2007. 6 US 6,888,704 B1, issued May 3, 2005. 7 WO 2005/101373 A1, published October 27, 2005. Appeal 2013-005578 Application 11/784,076 4 Pinarbasi and Horng A, further in view of Diao; and 6. Claim 26 as unpatentable over the combination of Pinarbasi and Horng A, further in view of Sbiaa. ANALYSIS Appellants argue dependent claim 5 and independent claim 17 separately, but do not otherwise argue the remaining claims separately. See generally Br. 6–8. In addition, the only argument colorably directed to claims other than claims 5 and 17 is merely Appellants’ assertion that none of Pinarbasi, Horng A, and Horng B, nor their combination, teaches or suggests the claimed method and structure for improving MR device performance by reducing lattice strain within the free layer. Id. at 6. However, this argument fails to address the rejection as articulated by the Examiner, and in particular, fails to identify reversible error in the Examiner’s findings, reasoning, or conclusion of obviousness. Indeed, the Examiner expressly found, and Appellants do not contest, that lattice strain reduction is an intended result or outcome of inserting a surfactant layer within the free layer, which the Examiner found to have been obvious based on the proposed combination of Pinarbasi, Horng A, and Horng B. Ans. 16– 17. As such, we summarily affirm rejections 1–3, except with regard to claim 5, which we separately discuss below. Cf. In re Baxter Travenol Labs., 952 F.2d 388, 391 (Fed. Cir. 1991) (“It is not the function of this court to examine the claims in greater detail than argued by an appellant, looking for nonobvious distinctions over the prior art.”). See also Ex parte Frye, 2010 WL 889747, *4 (BPAI 2010) (“Filing a Board appeal does not, Appeal 2013-005578 Application 11/784,076 5 unto itself, entitle an appellant to de novo review of all aspects of a rejection. If an appellant fails to present arguments on a particular issue — or, more broadly, on a particular rejection — the Board will not, as a general matter, unilaterally review those uncontested aspects of the rejection.”) (cited with approval in In re Jung, 637 F.3d 1356, 1365 (Fed. Cir. 2011) (“it has long been the Board’s practice to require an applicant to identify the alleged error in the examiner’s rejections”)). Claim 5 We sustain the Examiner’s rejection of claim 5 based on the findings of fact, conclusions of law, and rebuttals to arguments well expressed by the Examiner in the Final Office Action and the Answer. The following comments are added for emphasis. Claim 5 depends from claim 4 and further requires that the step of forming the surfactant layer includes admitting an oxygen/noble gas mixture to a pressure level of about 5x10-7 torr, for between about 5–60 seconds. The Examiner finds that Pinarbasi teaches a process for forming a magnetic memory cell free layer as recited in claim 4, wherein an oxide layer is formed between two ferromagnetic layers thereby providing a smoother interface between the ferromagnetic layers. Ans. 8. However, the Examiner acknowledges that Pinarbasi does not explicitly refer to the oxide layer as a surfactant layer, but finds that Horng A teaches an oxygen surfactant layer promotes planar growth for forming subsequent layers, wherein the oxygen surfactant layer causes oxidation of the underlying ferromagnetic layer. Id. In addition, the Examiner acknowledges that Pinarbasi and Horng A do not teach forming the surfactant layer using a mixture of oxygen and a noble gas, but finds Horng B teaches this feature. Id. As to claim 5, the Examiner Appeal 2013-005578 Application 11/784,076 6 finds that Horng B does not disclose the oxygen/noble gas mixture is at 5x10-7 torr and is maintained for 5–60 seconds. Id. Nonetheless, the Examiner concludes it would have been obvious to use such a pressure and time period by routine process optimization. Id. Appellants argue that because the pressures recited in claim 5 and Horng B differ by two orders of magnitude, an ordinary artisan would have no reason to optimize by experimentation with pressures 100 times greater than taught in Horng B. Br. 6. In addition, Appellants argue that because the claimed pressure does not require the use of an ultra-high vacuum system whereas Horng B does, Horng B’s method cannot read on the present invention. Id. at 6–7. Appellants further argue that the Examiner’s position that the thickness of a deposited film depends on the product of deposition rate and time holds no relevance to the optimum pressure “since many other factors . . . can influence the effectiveness of the surfactant.” Id. at 7. The Examiner responds that cost is one reason why an ordinary artisan would optimize pressure, recognizing that ultra-high vacuums are more costly, but may provide higher quality deposited layers, while lower vacuums are cheaper but may provide lower quality layers. Ans. 17 (directing attention to Appellants’ argument that the claimed pressure is less costly). Moreover, the Examiner finds, and Appellants do not contest, that one of ordinary skill in the art would routinely optimize not just pressure, but other variables, including time to achieve the desired deposited layer. Id. at 18. The Examiner further notes that Appellants provide no evidence that the pressure recited in claim 5 is critical in the manufacture of the oxygen surfactant layer. Id. Appeal 2013-005578 Application 11/784,076 7 We do not find Appellants’ arguments warrant reversal of the Examiner’s rejection because Appellants have neither presented evidence nor persuasive reasoning why one of ordinary skill in the art would not have found it obvious to perform routine optimization on the known parameters, including pressure, of the prior art deposition process. Indeed, as the Examiner expressly finds, and Appellants do not contest, one of ordinary skill in the art would recognize that use of lower vacuum levels (higher pressures) than Horng B’s preferred pressure would be less expensive. KSR Int'l Co. v. Teleflex, Inc., 550 U.S. 398,417 (2007) (“[w]hen a work is available in one field of endeavor, design incentives and other market forces can prompt variations of it, either in the same field or a different one.”); see also In re Thompson, 545 F2d 1290, 1294 (CCPA 1976) (economic factors alone may motivate one of ordinary skill to modify the prior art). Accordingly, we will sustain the Examiner’s rejection of claim 5. Claim 17 The Examiner finds Pinarbasi teaches a magnetic memory cell including an oxide layer sandwiching and providing a smooth interface between a pair of ferromagnetic layers forming a free layer. Ans. 12. However, the Examiner acknowledges that Pinarbasi does not explicitly refer to the oxide layer as a surfactant layer, but finds that Horng A teaches an oxygen surfactant layer promotes planar growth for forming subsequent layers, wherein the oxygen surfactant layer causes oxidation of the underlying ferromagnetic layer. Id. at 12–13. The Examiner concludes it would have been obvious to substitute Pinarbasi’s oxide layer with an oxygen surfactant layer because Horng A teaches the surfactant layer causes Appeal 2013-005578 Application 11/784,076 8 oxidation of the underlying ferromagnetic layer and both the oxide and surfactant layers create a smooth interface between adjacent layers. Id. at 13. Appellants initially contend that Pinarbasi teaches away from the claimed invention by teaching that the oxide layer is not any oxide, but is an oxide of CoFe. Br. 7. We do not find this argument persuasive because Appellants do not provide any evidence or argument as to why Pinarbasi teaches away from the claimed invention. “A reference may be said to teach away when a person of ordinary skill, upon reading the reference, would be discouraged from following the path set out in the reference, or would be led in a direction divergent from the path that was taken by the applicant.” In re Gurley, 27 F.3d 551, 553 (Fed. Cir. 1994). The prior art’s mere disclosure of a particular oxide layer does not constitute a teaching away because such disclosure does not criticize, discredit, or otherwise discourage the solution as recited in claim 17. Indeed, as the Examiner finds, Pinarbasi’s teaching is an indication that the oxide layer is formed by oxidizing the underlying ferromagnetic layer (Ans. 18), precisely the teaching of Horng A (id.). Appellants further argue that the Examiner’s rejection is invalid because i) “[i]t is incorrect that any material that contains oxygen will act as a surfactant”, ii) “[t]he vast majority of surfactants do not cause the formation of an oxide layer”, iii) “[t]he formation of an oxide could actually be counter-productive because, while surfactants serve to improve wettability, most oxides are known to have the opposite effect”, and iv) Appeal 2013-005578 Application 11/784,076 9 Barabasi8 has no relevance to the claims because there is no mention of lattice strain. Br. 8. None of these arguments is persuasive of reversible error in the Examiner’s rejection. We note that Appellants fail to direct our attention to any evidentiary support for the assertions made in arguments i– iii. In addition, we note the Examiner does not rely on Barabasi in support of the rejection. The Examiner further calls into question the assertions made in Appellants’ arguments by finding, without dispute, that Pinarbasi’s oxide layer and Horng A’s surfactant layers are equivalents based on the findings that Horng A teaches the oxygen surfactant layer oxidizes the underlying layer and creates a smooth interface for planar growth of subsequent layers. Ans. 19. Based on our consideration of the totality of the record before us, we have weighed the evidence of obviousness found in the Examiner’s Answer, Pinarbasi and Horng A, with Appellants’ countervailing arguments for nonobviousness and conclude, by a preponderance of the evidence and weight of argument, that the claimed invention encompassed by appealed claim 17 would have been obvious as a matter of law under 35 U.S.C. § 103(a). Appellants have not argued claims 18–28 separately. Accordingly, we will sustain the Examiner’s rejection of these claims for the reasons given for claim 17 above. DECISION 8 Albert-László Barabási, “Surfactant-mediated Surface Growth: Nonequilibrium Theory,” Fractals, World Scientific Publishing Company, vol. 1, no. 4 (1993), 846–859. Appeal 2013-005578 Application 11/784,076 10 Upon consideration of the record, and for the reasons given above and in the Answer, the decision of the Examiner rejecting claims 1 and 3–28 as unpatentable under 35 U.S.C. § 103(a) is affirmed. TIME PERIOD FOR RESPONSE 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 [kmm] Copy with citationCopy as parenthetical citation