Ex Parte Ishibashi et al

Patent Trials and Appeals BoardSep 10, 2018

14151719 - (D) (P.T.A.B. Sep. 10, 2018)

UNITED STA TES p A TENT AND TRADEMARK OFFICE APPLICATION NO. FILING DATE FIRST NAMED INVENTOR 14/151,719 01/09/2014 Keiji Ishibashi 26694 7590 09/12/2018 VENABLELLP P.O. BOX 34385 WASHINGTON, DC 20043-9998 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 ATTORNEY DOCKET NO. CONFIRMATION NO. 40616-358468 1080 EXAMINER SONG, MATTHEW J ART UNIT PAPER NUMBER 1714 NOTIFICATION DATE DELIVERY MODE 09/12/2018 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): PTOMail@Venable.com khauser@venable.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte KEIJI ISHIBASHI and TAKA YUKI NISHIURA Appeal2017-010582 Application 14/151, 719 1 Technology Center 1700 Before BRADLEY R. GARRIS, LINDA M. GAUDETTE, and SHELDON M. McGEE, Administrative Patent Judges. McGEE, Administrative Patent Judge. DECISION ON APPEAL Pursuant to 35 U.S.C. Â§ 134, Appellant seeks our review of the Examiner's rejections of claims 1-7. Br. 8. We have jurisdiction. 35 U.S.C. Â§ 6. We affirm. 1 Appellant is the Applicant, Sumitomo Electric Industries, Ltd., and is identified as the real party in interest. Br. 1. Appeal2017-010582 Application 14/151, 719 BACKGROUND The subject matter on appeal is directed to a Group III nitride crystal substrate, e.g., GaN or AlN, which has been subjected to a surface treatment process. Spec. 1: 15-2:2. Such crystals may be used as the substrate of certain semiconductor devices such as light-emitting devices, e.g., light- emitting diodes and laser diodes. Spec. 21: 19-21. Sole independent claim 1 is illustrative of the appealed subject matter, and is copied below from the Claims Appendix to the Appeal Brief, with emphasis added to relevant limitations at issue in this appeal: 1. A Group III nitride crystal substrate for growing an epitaxial layer in which the Group III nitride crystal substrate is used for growing an epitaxial layer on the Group III nitride crystal substrate, wherein the Group III nitride crystal substrate has a swface roughness Ra of 0.5 nm or less, the Group III nitride crystal substrate has an affected layer in which crystal lattices are out of order and the affected layer has a thickness of 50 nm or less, and the Group III nitride crystal substrate either has a principal plane parallel to any plane of A-plane and M-plane in the wurtzite structure or has an off-angle formed by the principal plane of the Group III nitride crystal substrate and any plane of A-plane and M-plane in the wurtzite structure being O. 0 5 Â° to 15 Â°, wherein a surface roughness Ry after polishing of the Group III nitride crystal substrate is 5 nm or less, wherein contents of each of Group III element atoms and nitrogen (N) atom on the surface of the Group III nitride crystal substrate is 40 to 60 atomic percent relative to the sum of the Group III element atoms and N atom on the surface of the Group III nitride crystal substrate, wherein each of the contents of O atom and C atom is 40 atomic percent or less relative to the atoms of all elements on the surface of the Group III nitride crystal substrate, wherein, for impurities on the surface of the Group III nitride crystal substrate, the content of atoms of elements each having an 2 Appeal2017-010582 Application 14/151, 719 atomic number of 1 to 18 except for oxygen (0) and carbon (C) is 1 x 1014 atomslcm2 or less, [and] wherein, for impurities on the surface of the Group III nitride crystal substrate, the content of atoms of elements each having an atomic number of 19 or more is 1 x 1012 atoms/cm2 or less. Br. 16. STATEMENT OF THE CASE The Examiner rejects claims 1-3 and 5-7 under 35 U.S.C. Â§ I03(a) as unpatentable over Tsuda, 2 in view of Xu 3 and Dwilinski. 4 Non-Final Act. 5 3---6. The Examiner also rejects claim 4 under 35 U.S.C. Â§ I03(a) as unpatentable over these references and additional prior art. Id. at 7. The Examiner finds, and Appellant does not dispute, that Tsuda teaches the recited Group III nitride crystal substrate, except for recited surface roughness values, surface impurities, and affected layer lattice order and thickness. Non-Final Act. 3--4. The Examiner relies on Xu and Dwilinski to address these differences. Id. at 4---6. Relevant to this appeal, the Examiner specifically finds that Xu discloses polishing a GaN wafer to "a surface roughness of below 0.3 nm." Id. at 4. The Examiner finds further that Dwilinski teaches an impurity removal process in a GaN wafer manufacturing process which, after "the desired level of impurities near the surface is reached," a higher quality crystal is produced. Id. at 5. The Examiner determines that it would have been obvious for the skilled artisan to modify Tsuda's process by polishing the crystal to have a surface roughness of less than 0.5 nm as taught by Xu in 2 US 2005/0095768 Al, published May 5, 2005. 3 US 6,488,767 Bl, issued December 3, 2002. 4 US 2006/0037530 Al, published February 23, 2006. 5 Non-Final Office Action dated September 22, 2016. 3 Appeal2017-010582 Application 14/151, 719 order "to produce a high quality surface suitable for epitaxial growth." Id. at 4. The Examiner determines further that it would have been obvious to modify the combination of Tsuda and Xu to remove impurities, as taught by Dwilinski, to arrive at the recited impurity levels "because high purity crystals are more desirable for device manufacturing." Id. at 5. OPINION Appellant presents arguments only directed to independent claim 1. Br. 8-13. We, therefore, select this claim as representative and decide the rejection of claims 1-3 and 5-7 on the basis of claim 1 alone. 37 C.F.R. Â§ 41.37 (c)(l)(iv). Appellant relies on the same arguments presented for claim 1 for separately rejected claim 4. Br. 14. Thus, all claims on appeal stand or fall with claim 1. Appellant first argues that the recited impurities are not disclosed or rendered obvious by the cited references. Br. 8-11. Specifically, Appellant urges that Dwilinski teaches annealing and processing of bulk mono- crystalline gallium-containing nitride, and not a "Group III nitride crystal substrate" as recited in claim 1. Id. Appellant argues that because Dwilinski's bulk mono-crystalline gallium-containing nitride "requires further processing such as slicing, polishing, and washing, in order to be prepared for growing an epitaxial layer," the portions of Dwilinski relied on by the Examiner do not establish that the recited surface impurity levels would be achieved. Id. at 10. Moreover, Appellants contend that "Dwilinski does not disclose or suggest" the combination of impurity ranges. Id. at 11. We are not persuaded by this line of argument. Rather, we agree with the Examiner's response to these arguments (Ans. 8-10)-particularly the 4 Appeal2017-010582 Application 14/151, 719 Examiner's determination that Dwilinski's teachings are not limited to the rinsing and annealing of bulk mono-crystalline gallium-containing nitride - and adopt the Examiner's analysis as our own findings and reasoning. See Dwilinski ,r,r 62-70. We emphasize that Appellant does not challenge the Examiner's response provided in the Answer, i.e., no Reply Brief has been filed. We furthermore note that Dwilinski appears to evince the result- effective nature of the purification process on the resulting level of surface impurities. Dwilinski discloses that impurities in bulk mono-crystalline gallium-containing nitride are reduced by an annealing process and produces "material with higher crystalline quality than before the annealing." Dwilinski ,r 58. Dwilinski teaches that the bulk mono-crystalline gallium- containing nitride may be subject to the annealing process either before and/or after it is sliced into wafers. Id. ,r 70. Dwilinski's "annealing process is carried out in a single step or in multiple steps until the desired level of impurities ... is reached." Id. ,r 61 ( emphasis added). Because the impurity level appears to be an art-recognized result-effective variable, it is incumbent on Appellant to demonstrate the criticality of the recited impurity level ranges. See In re Antonie, 559 F .2d 618, 620 (CCP A 1977); In re Aller, 220 F.2d 454, 456 (CCPA 1955). Here, no evidence has been proffered by Appellant demonstrating such criticality. Appellant argues further that Xu teaches a different "surface roughness" unit of measurement- root mean square, or "RMS" roughness - as opposed to the recited Ra and Ry values. Br. 11-13. Specifically, Appellant asserts that the skilled artisan would have recognized that RMS roughness as disclosed by Xu is different than the surface roughness "Ra" and "Ry" values recited in claim 1, and "would not interpret the RMS 5 Appeal2017-010582 Application 14/151, 719 roughness of Xu to be equivalent, or even necessarily comparable to, the surface roughness Ra of claim 1." Id. at 12. This argument fails to persuade us of reversible error in the rejection. The Examiner readily acknowledges that there are differences in the calculations to arrive at RMS, Ra, and Ry roughness values. Non-Final Act. 8; Ans. 10. Appellant's argument, however, does not address, much less reveal error in, the Examiner's findings regarding the substantial similarities between Xu's polishing process and that disclosed in the Specification, nor the Examiner's determination that Xu's crystal "would be expected to have the claimed roughness characteristics." Non-Final Act. 5, 8; Ans. 9. "Where, as here, the claimed and prior art products ... are produced by identical or substantially identical processes, the PTO can require an applicant to prove that the prior art products do not necessarily or inherently possess the characteristics of [the] claimed product." In re Best, 562 F.2d 1252, 1255 (CCPA 1977). In this case, Appellant has not addressed the Examiner's determination that Xu's polished wafer (RMS roughness of 0.28 nm) is likely to meet the recited Ry limitation of "greater than 5 nm ... which is over 17 times larger than the 0.28 nm RMS obtained in [Xu's] Example 3." Ans. 10-11. Because the Examiner properly shifted the burden to Appellant to demonstrate that Xu's wafer does not meet the recited roughness measurements, and because Appellant fails to proffer any evidence supporting such a showing (Br., generally), Appellant's arguments regarding differences in Xu's units of measurement fall short of revealing error in the Examiner's rejection. Thus, for these reasons, and for those expressed by the Examiner in the Non-Final Action and in the Answer, we sustain the obviousness rejections of claims 1-7. 6 Appeal2017-010582 Application 14/151, 719 DECISION The Examiner's decision to reject claims 1-7 is affirmed. No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. Â§ 1.136(a). AFFIRMED 7