09922122 (B.P.A.I. May. 5, 2009)

Ex Parte Marchand et al

Board of Patent Appeals and InterferencesMay 5, 2009

09922122 (B.P.A.I. May. 5, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE ________________ BEFORE THE BOARD OF PATENT APPEALS AND INTERFERENCES ________________ Ex parte HUGUES MARCHAND and BRENDAN JUDE MORAN ________________ Appeal 2009-2232 Application 09/922,122 Technology Center 1700 ________________ Decided:1 May 5, 2009 ________________ Before EDWARD C. KIMLIN, TERRY J. OWENS, and JEFFREY T. SMITH, Administrative Patent Judges. OWENS, Administrative Patent Judge. DECISION ON APPEAL STATEMENT OF THE CASE The Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s rejection of claims 1, 2, 4-9, 11-17, 35, and 38. Claims 18-34, which are all of the other pending claims, stand withdrawn from consideration by the Examiner. We have jurisdiction under 35 U.S.C. § 6(b). 1 The two-month time period for filing an appeal or commencing a civil action, as recited in 37 C.F.R. § 1.304, begins to run from the Decided Date shown on this page of the decision. The time period does not run from the Mail Date (paper delivery) or Notification Date (electronic delivery). Appeal 2009-2232 Application 09/922,122 2 The Invention The Appellants claim a semiconductor film comprising a single crystal graded gallium nitride layer that is on a silicon substrate and has a net compressive stress. Claim 1 is illustrative: 1. A semiconductor film, comprising: a silicon substrate; and a single crystal graded gallium nitride layer deposited on the silicon substrate having a varying composition of a substantially continuous grade from an initial composition to a final composition and a net compressive stress. The References Redwing 5,874,747 Feb. 23, 1999 Tischler 6,765,240 B2 Jul. 20, 2004 (effective filing data on or before Oct. 21, 1997) The Rejections The claims stand rejected as follows: claims 1, 2, 4-9, 15-17, 35, and 38 under 35 U.S.C. § 102(e) over Tischler, and claims 11-14 under 35 U.S.C. § 103 over Tischler in view of Redwing. OPINION We reverse the Examiner’s rejections. We need to address only the rejection of claim 1, which us the sole independent claim. The Examiner does not rely upon Redwing for any disclosure that would have rendered prima facie obvious, to one of ordinary skill in the art, any subject matter in the Appellants’ claim 1 not disclosed by Tischler (Ans. 5-6). Appeal 2009-2232 Application 09/922,122 3 Issue Have the Appellants shown reversible error in the Examiner’s determination that Tischler discloses, expressly or inherently, a graded gallium nitride layer having a net compressive stress? Findings of Fact Tischler discloses “bulk single crystal binary, ternary or quaternary metal nitrides such as gallium nitride” (col. 1, ll. 10-11). The ternary or quaternary metal nitrides can be of graded composition such as AlGaN or AlGaInN (col. 7, ll. 13-16; col. 12, ll. 37-38). Tischler points out that defects in the form of dislocations generated during cool-down after growth of the nitride layer can result due to different thermal coefficients of expansion of the nitride layer and the substrate on which it is grown (col. 4, ll. 61-63). Tischler eliminates such defects by in-situ removal of the substrate (which can be silicon (col. 2, ll. 47-48)) by, for example, etching, at or near the growth temperature, i.e., within 300°C, most preferably within 25°C, of the 800-1300°C growth temperature (col. 5, ll. 5-10, 34-40, 58-62; col. 6, ll. 45-48, 59-60). The remaining free-standing metal nitride then is cooled (col. 6, ll. 63-64). Analysis “Anticipation requires that every limitation of the claim in issue be disclosed, either expressly or under principles of inherency, in a single prior art reference.” Corning Glass Works v. Sumitomo Elec. U.S.A., Inc., 868 F.2d 1251, 1255-56 (Fed. Cir. 1989). The Appellants argue that there is no evidence that Tischler’s free- standing layer, while still on the substrate and cooled to only 300°C or less below the 800-1300°C growth temperature, has a net compressive stress Appeal 2009-2232 Application 09/922,122 4 (Reply Br. 5-7). The Appellants argue that when Tischler’s free-standing nitride layer is cooled it is not subject to thermal mismatch and, therefore, should be stress free (Br. 6; Reply Br. 6). The Examiner argues that the Appellants’ disclosure that “a larger amount of compressive strain is present in the layer structure than is found when using other methods” (Spec. 8:2-3) is an admission that other methods produce compressive strain (Ans. 3). The compressive strain referred to by the Appellants is that induced by a cool-down procedure (Spec. 8:2-5). That disclosure by the Appellants is not an admission that Tischler’s layer structure within 300°C of the 800- 1300°C growth temperature has compressive strain. The Examiner argues that “Tischler et al disclose that a single crystal has no defects from thermal coefficient of expansion differences, i.e.[,] cracks (col 12, ln 45-65 and col 13, ln 1-5), which is further evidence that there is a net compressive stress because appellant discloses that crack free graded GaN has a net compressive stress, note page 8, lines 1-10 of the specification” (Ans. 3). Tischler’s disclosure that the single crystal nitride has no defects from thermal coefficient of expansion differences pertains to the single crystal nitride after being removed from the substrate at a temperature within 300°C of the 800-1300°C growth temperature and then cooled (col. 6, ll. 45-47, 63- 64). The Examiner has not established that this disclosure is relevant to whether the single crystal nitride is under net compressive stress while still on the substrate at a temperature within 300°C of the growth temperature, which is the structure the Examiner relies upon as corresponding to the Appellants’ graded gallium nitride layer on a substrate (Ans. 6). Appeal 2009-2232 Application 09/922,122 5 The Examiner argues that Tischler’s cooling to within 300°C of the growth temperature causes compressive stress but does not cause tensile stress (Ans. 7). That argument is not persuasive because it is not supported by evidence. The Examiner argues that before Tischler’s substrate is removed there is some stress due to the difference in coefficients of thermal expansion between the nitride layer and the substrate (Ans. 7-8). Even if that argument is correct, the Examiner has not established that the stress is a net compressive stress. Conclusion of Law The Appellants have shown reversible error in the Examiner’s determination that Tischler discloses, expressly or inherently, a graded nitride layer having a net compressive stress. DECISION/ORDER The rejections of claims 1, 2, 4-9, 15-17, 35, and 38 under 35 U.S.C. § 102(e) over Tischler, and claims 11-14 under 35 U.S.C. § 103 over Tischler in view of Redwing are reversed. It is ordered that the Examiner’s decision is reversed. REVERSED PL Initial sld Appeal 2009-2232 Application 09/922,122 6 GATE & COOPER LLP HOWARD HUGHES CENTER 6701 CENTER DRIVE WEST, SUITE 1050 LOS ANGELES, CA 90045