10923036 (B.P.A.I. Jun. 13, 2012)

Ex Parte Song et al

Board of Patent Appeals and InterferencesJun 13, 2012

10923036 (B.P.A.I. Jun. 13, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE ____________________ BEFORE THE BOARD OF PATENT APPEALS AND INTERFERENCES ____________________ Ex parte JUNE-O SONG, DONG-SEOK LEEM, and TAE-YEON SEONG ____________________ Appeal 2010-004456 Application 10/923,0361 Technology Center 2800 ____________________ Before: MARC S. HOFF, CARLA M. KRIVAK, and ELENI MANTIS MERCADER, Administrative Patent Judges. HOFF, Administrative Patent Judge. DECISION ON APPEAL 1 The real party in interest is Samsung Electronics Co., Ltd. Appeal 2010-004456 Application 10/923,036 2 STATEMENT OF THE CASE Appellants appeal under 35 U.S.C. § 134(a) from a final rejection of claims 1-16.2 We have jurisdiction under 35 U.S.C. § 6(b). We affirm. Appellants’ claimed invention “relates to a thin film electrode for a light emitting device, and more particularly, to a transparent thin film electrode for a light emitting diode (LED) or a laser diode (LD), which is formed on the surface of a p-type semiconductor containing at least nitrogen (N) and gallium (Ga).” Specification 1. Independent claim 1, reproduced below, is representative of the subject matter on appeal. 1. A semiconductor structure comprising: a transparent thin film electrode; and a p-type semiconductor having at least nitrogen (N) and gallium (Ga), wherein the transparent thin film electrode comprises: a copper (Cu)-based conductive metal layer consisting essentially of Cu and another non-oxide metal, located in contact with said p-type semiconductor; and a metal capping layer formed on the entire surface of the upper surface of the Cu-based conductive metal layer. 2 The Examiner notes that claims 1-3, 8, and 11are substantially incorrect and has appended a correct copy of these claims to the Answer (Ans. 3). We will consider the corrected copy of these claims from the Answer in this appeal. Claims 17 and 18 have been cancelled. Appeal 2010-004456 Application 10/923,036 3 REFERENCES and REJECTION The Examiner relies upon the following prior art in rejecting the claims on appeal: Nitta US Patent App. Pub. No. 2002/0163302 A1 Nov. 7, 2002 Ho US Patent App. Pub. No. 2002/0185732 A1 Dec. 12, 2002 The Examiner rejected claims 1-16 under 35 U.S.C. § 103(a) as being unpatentable over Nita and Ho. ISSUE Appellants argue that Ho does not teach a transparent metal layer on a p-type semiconductor because Ho teaches that the metal layer (24) cited by the Examiner can be substituted with a transparent conductive film (App. Br. 4-5). Appellants reason that this teaching means that Ho’s metal layer is not transparent (id.). Appellants further argue that because bonding pad 129 of Nitta already provides low resistance between bonding pad 129 and electrode 128, one of ordinary skill in the art would not have been motivated to add a further layer between electrode 128 and pad 129 to reduce contact resistance (Reply Br. 7). The Examiner finds that Ho’s teaching of possible substitution of transparent conductive film for metal layer 24 does not lead to a conclusion that, if the electrode is to be transparent, metal is not used (Ans. 8-9), and cites evidence that transparent metal layers are generally not explicitly referred to as “transparent metals” (id. at 9). Appellants’ arguments and the Examiner’s finding present us with the following issue: Appeal 2010-004456 Application 10/923,036 4 Would it have been obvious to modify Nitta to include a metal capping layer formed on the entire surface of the upper surface of the copper-based conductive metal layer, in view of the teachings of Ho? PRINCIPLES OF LAW Section 103(a) forbids issuance of a patent when “the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains.” KSR Int’l Co. v. Teleflex, Inc., 550 U.S. 398, 406 (2007). The question of obviousness is resolved on the basis of underlying factual determinations including (1) the scope and content of the prior art, (2) any differences between the claimed subject matter and the prior art, (3) the level of skill in the art, and (4) where in evidence, so-called secondary considerations. Graham v. John Deere Co. of Kansas City, 383 U.S. 1, 17-18 (1966). See also KSR, 550 U.S. at 407, (“While the sequence of these questions might be reordered in any particular case, the [Graham] factors continue to define the inquiry that controls.”) ANALYSIS We are not persuaded by Appellants’ argument, summarized supra, that Ho “effectively teaches away from including metal layer 24 in a transparent electrode” (App. Br. 5). We agree with the Examiner’s finding that Ho teaches “a layer of metal 24 on the p-type GaN 10 to form an ohmic contact to p-type GaN” (¶ [0027]). We further agree with the Examiner that Appeal 2010-004456 Application 10/923,036 5 Ho’s teaching that metal layer 24 “can be replaced by] a transparent conductive film” does not necessarily mean that metal layer 24 is not transparent (Ans. 8-9). We agree with the Examiner that “a transparent electrode may be formed of thin layers of metal” (id. at 9), and that transparent layers of metal are not typically referred to as “transparent metals” in the art (id.). Appellants’ argument that the skilled artisan would not be motivated to include the metal capping layer taught by Ho to achieve reduced contact resistance, because pad 129 of Nitta already provides reduced contact resistance (Reply Br. 7), is also unpersuasive. To the extent that Appellants and the Examiner agree that reduced contact resistance is desirable, we find that the further reduction in contact resistance provided by a metal capping layer would have been a desired property, even if bonding pad 129’s wide area had already reduced the contact resistance between pad 129 and electrode 128. We conclude that it would have been obvious to modify Nitta to include the metal capping layer of Ho to achieve the invention under appeal. Thus, we will sustain the Examiner’s § 103 rejection of claims 1-16 as being unpatentable over Nitta in view of Ho. CONCLUSION It would have been obvious to modify Nitta to include a metal capping layer formed on the entire surface of the upper surface of the copper-based conductive metal layer, in view of the teachings of Ho. Appeal 2010-004456 Application 10/923,036 6 DECISION The Examiner’s decision rejecting claims 1-16 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)(iv)(2011). AFFIRMED vsh/llw