Ex Parte Lin et alDownload PDFPatent Trial and Appeal BoardOct 29, 201312322118 (P.T.A.B. Oct. 29, 2013) Copy Citation 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. 12/322,118 01/27/2009 Wei-Jung Lin N1085-00586 6209 54657 7590 10/29/2013 DUANE MORRIS LLP (TSMC) IP DEPARTMENT 30 SOUTH 17TH STREET PHILADELPHIA, PA 19103-4196 EXAMINER PHAM, THANH V ART UNIT PAPER NUMBER 2899 MAIL DATE DELIVERY MODE 10/29/2013 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 WEI-JUNG LIN, CHENG-TUNG LIN, CHIH-WEI CHANG, and SHAU-LIN SHUE __________ Appeal 2011-008198 Application 12/322,118 Technology Center 2800 ____________ Before ROMULO H. DELMENDO, MARK NAGUMO, and MICHAEL P. COLAIANNI, Administrative Patent Judges. COLAIANNI, Administrative Patent Judge. DECISION ON APPEAL Appellants appeal under 35 U.S.C. § 134 the final rejection of claims 1-10. We have jurisdiction over the appeal pursuant to 35 U.S.C. § 6(b). We REVERSE. Appellants’ invention is directed to a semiconductor device with a controlled work function defined as “the minimum energy needed to remove an electron from the Fermi level in a metal to a point at infinite distance Appeal 2011-008198 Application 12/322,118 2 away outside the surface” (Spec. paras. [0002], [0007]). The device includes silicide layers of a first phase (e.g., NiSi) and a second phase (e.g., Ni2Si) to tune or optimize the work function of the device for a particular application. (Spec. paras. [0005], [0015]). Claim 1 is illustrative: 1. A semiconductor device comprising: a semiconductor substrate; a gate dielectric disposed over the substrate; a first metal silicide layer disposed over the gate dielectric, wherein the first metal silicide has a first phase; wherein the first metal silicide layer comprises at least one alloy element; and a second metal silicide layer disposed over the first metal silicide layer, wherein the second metal silicide has a second phase; wherein the first metal silicide and second metal silicide comprise the same metal and the first and second phases are different. Appellants appeal the following rejections: 1. Claims 1-5 are rejected under 35 U.S.C. § 102(a), as being unpatentable over Liu1 (US 2006/0084247 A1, published Apr. 20, 2006). 2. Claims 6-10 are rejected under 35 U.S.C. §§ 102(a)/103(a) as being unpatentable over Liu. 1 As argued in the Reply Brief filed April 20, 2011 at pages 4-5, the Examiner relies on Nishida (US Patent 5,384,485) for the first time in the Response to Arguments section of the Answer to support the § 102(a) rejection over Liu (Ans. 3, 5-6). We shall not consider Nishida because where a reference is relied on to support a rejection, whether or not in a “minor capacity,” there would appear to be no excuse for not positively including the reference in the statement of the rejection. In re Hoch, 428 F.2d 1341, 1342 n. 3 (CCPA 1970). Appeal 2011-008198 Application 12/322,118 3 ISSUE Did the Examiner reversibly err finding that Liu discloses forming a second metal silicide layer disposed over a first metal silicide layer on a gate dielectric wherein the second metal silicide layer has a second phase different than the first phase of the first metal silicide layer as required by claim 1? We decide this issue in the affirmative. FINDINGS OF FACT AND ANALYSES Appellants argue that Liu fails to teach two metal silicide layers over the gate dielectric (App. Br. 7). Appellants contend that is in unclear what the resulting structure is from Liu’s second annealing step that forms the NiSi layer 390 over the source and drain (S/D) regions of the semiconductor and somewhat nickel enriches the higher resistivity nickel disilicide gate 380 (Reply Br. 3-4; Liu’s Fig. 3G and para. [0184]). Appellants contend that Liu’s disclosure fails to teach a second silicide layer as recited in claim 1. Id. The Examiner responds that paragraph 184 of Liu discloses that the annealing treatment to form the NiSi layer over the source and drain region of the semiconductor device somewhat enriches the nickel disilicide gate layer, which results in a nickel-enriched silicide layer (Ans. 4, 5). However, the Examiner’s inherency position is improperly based upon possibilities and probabilities that the claimed second silicide layer results from the nickel enriching of the nickel disilicide gate layer. In re Oelrich, 666 F.2d 578, 581 (CCPA 1981)). The claim requires that the second silicide layer have a second phase different than the phase of the first Appeal 2011-008198 Application 12/322,118 4 silicide layer (claim 1). It is unclear whether the “somewhat nickel enriched” nickel disilicide layer 380 disclosed in Liu results in a nickel layer having a different phase or whether nickel from the nickel layer 350 used to form the NiSi layer over the source and drain regions simply results in more nickel being present in the surface region of the nickel disilicide layer 380 with no change in the phase. While the Examiner contends that Liu’s post annealing step would provide another layer of silicide of a different phase (Ans. 6), the Examiner has not provided a basis-in-fact or technical reasoning to support the finding that a second silicide layer as recited in claim 1 forms via the nickel enrichment of the metal disilicide gate material. Ex parte Levy, 17 USPQ2d 1461, 1464 (BPAI 1990). On this record, the Examiner has not dispensed with the burden of establishing a prima facie case of anticipation. Because claim 1 is the only independent claim on appeal and the Examiner does not address the above- mentioned shortcomings of Liu in the context of the § 103 rejection of claims 6-10, we reverse the Examiner’s § 102 and § 103 rejections. DECISION The Examiner’s decision is reversed. ORDER REVERSED cam Copy with citationCopy as parenthetical citation