Ex Parte Gupta et alDownload PDFPatent Trial and Appeal BoardMar 31, 201611150879 (P.T.A.B. Mar. 31, 2016) Copy Citation UNITED STA TES p A TENT AND TRADEMARK OFFICE APPLICATION NO. FILING DATE 111150,879 0610912005 7590 04/01/2016 The Law Offices of Calvin B, Ward Suite 305 18 Crow Canyon Court San Ramon, CA 94583 FIRST NAMED INVENTOR Subhash Gupta 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. 54364-Div 3537 EXAMINER MITCHELL, JAMES M ART UNIT PAPER NUMBER 4100 MAILDATE DELIVERY MODE 04/01/2016 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 SUBHASH GUPTA, PAUL KWOK KEUNG HO, and SANGKIHONG Appeal2014-005702 Application 11/150,879 Technology Center 4100 Before PETER F. KRATZ, KAREN M. HASTINGS, and CHRISTOPHER C. KENNEDY, Administrative Patent Judges. HASTINGS, Administrative Patent Judge. DECISION ON APPEAL Appellants 1 seek our review under 35 U.S.C. § 134 of the Examiner's final decision rejecting claims 11-16 under 35 U.S.C. § 103(a) as unpatentable over at least the basic combination of Hayasaka et al. (U.S. 6,809,421 Bl, issued Oct. 26, 2004) ("Hayasaka") in combination with Leedy (U.S. 2001/0033030 Al, published Oct. 25, 2001) and Atkins et al. 1 The Real Party in Interest is stated to be "Tezzaron Semiconductor Corporation" (Br. 1 ). Appeal2014-005702 Application 11/150,879 (U.S. 5,798,565, issued Aug. 25, 1998) ("Atkins").2 We have jurisdiction over the appeal under 35 U.S.C. § 6(b). We AFFIRM. Claims 11 and 14 are illustrative of the claimed subject matter (emphasis added): 11. A method for thinning a wafer to provide a component layer comprising an integrated circuit layer, said component layer having a predetermined thickness, said method comprising: providing a wafer having first and second surfaces comprising a wafer material with said integrated circuit layer fabricated on said first surface thereof; generating a plurality of vias, each via extending from said first surface to a first depth, said plurality of vias being characterized by a lateral density on said wafer; depositing a layer of a stop material in said vias, said stop material being more resistant to CMP than said wafer material; and removing material from said second surface of said wafer utilizing CMP to provide an etched surface at said first depth from said first surface, said layer of stop material preventing said CMP from removing wafer material closer to said first surface than said first depth, and said lateral density of said vias being sufficient to provide a planar surface that can be bonded to another wafer by thermal diffusion bonding. 14. A method for adding a second component layer comprising an integrated circuit layer to a first wafer comprising a first circuit layer, said method comprising the steps of: providing a plurality of bonding pads on a first surf ace of said first wafer; 2 The Examiner applies the additional prior art of Lasky (U.S. 4,735,679, issued Apr. 5, 1988) to claims 12 and 15; and Huang et al. (U.S. 2005/0258537 Al, published Nov. 24, 2005) ("Huang") to claim 14. 2 Appeal2014-005702 Application 11/150,879 providing a second wafer compnsmg a substrate of a wafer material and said integrated circuit layer, said integrated circuit layer being fabricated on a first surface of said substrate and being covered by a layer of dielectric material, said second wafer further comprising a plurality of vias extending a predetermined distance from said first surface of said substrate into said substrate, said vias including a layer of stop material, said stop material being more resistant to CMP than said wafer material; providing a plurality of bonding pads on said second wafer, there being a one to one correspondence between said bonding pads on said first and second wafers; positioning said first and second wafers such that said bonding pads on said first wafer are brought in direct contact with said bonding pads on said second wafer without any intervening material being present between said bonding pads of said first wafer and said bonding pads of said second wafer; causing said corresponding bonding pads to bond to one another; and removing a portion of said second wafer by CMP of the surface of said second wafer that is not bonded to said first wafer, said stop layer in said vias determining the amount of material that is removed. ANALYSIS We have reviewed each of Appellants' arguments for patentability. However, we are in agreement with the Examiner that the claimed subject matter is unpatentable under § 103 in view of the applied prior art. Accordingly, we sustain the Examiner's prior art rejections for the reasons explained in the Answer, and we add the following primarily for emphasis. In construing claims, "the PTO must give claims their broadest reasonable construction consistent with the specification .... Therefore, we look to the specification to see if it provides a definition for claim terms, but otherwise apply a broad interpretation." In re ICON Health & Fitness, Inc., 3 Appeal2014-005702 Application 11/150,879 496 F.3d 1374, 1379 (Fed. Cir. 2007). "[A]s applicants may amend claims to narrow their scope, a broad construction during prosecution creates no unfairness to the applicant or patentee." Id. Appellants' main argument is that Hayasaka teaches away from the combination of the method of formation of a multichip semiconductor device of Hayasaka with the method of formation of the three dimensional structure comprising integrated circuits of Leedy because "Hayasaka contemplated wafer scale bonding and proceeding in a different direction" (Br. 8). Whether a reference teaches away from a claimed invention is a question of fact. In re Harris, 409 F.3d 1339, 1341 (Fed. Cir. 2005). "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 ). In evaluating references it is proper to take into account not only the specific teachings of the references but also the inferences which one skilled in the art would reasonably be expected to draw therefrom. In re Fritch, 972 F.2d 1260, 1264--65 (Fed. Cir. 1992); In re Preda, 401 F.2d 825, 826 (CCP A 1968). Notably, our reviewing court has also determined that a reference can distinguish prior art in order to show the novelty of an invention without teaching away from combining the prior art with the invention disclosed in the reference. See Ricoh Co., Ltd. v. Quanta Computer Inc., 550 F.3d 1325, 1332 (Fed. Cir. 2008). As pointed out by the Examiner, both Hayasaka and Leedy exemplify the process of utilizing pads having exposed surfaces capable of bonding via 4 Appeal2014-005702 Application 11/150,879 heat treatment (e.g., Ans. 12). Appellants have not directed us to persuasive evidence that discourages the use of thermal diffusion bonding in this environment. In re Gurley, 27 F.3d at 553. Thus, Appellants' argument that Hayasaka teaches away from the claimed invention is not persuasive of reversible error. Notably, claim 11 does not require any step of "thermal diffusion bonding" (as it merely requires that the surface "can be bonded to another wafer by thermal diffusion bonding"). Claim 14 requires bonding without any intervening material therebetween. Appellants argue that the preparation of the pads as planar surfaces required to enable thermal bonding would require significant modification of the Hayasaka reference to flatten the bonding surfaces to enable combination with Leedy and Atkins references wherein thermal diffusion is taught (e.g., Br. 8). This argument is also not persuasive of reversible error. As the Examiner points out, Hayasaka teaches CMP processing, the use of vias, as well as etch stop (i.e., etchback) (col. 12, 11. 60-64), and the instant application likewise uses these same processes to prepare planar surfaces (Spec. 9: 1-8; Ans. 10). As previously discussed, claim 11 merely requires that the "planar surface that can be bonded to another by thermal diffusion bonding." So long as two surfaces can contact one another, then thermal bonding can occur. No degree of flatness is required nor claimed. (See Ans. 10). Thus, the Examiner's determination that the surface flatness achieved in Hayasaka alone, and certainly in the combined Hayasaka/Leedy/ Atkins combination, would have been capable of thermal diffusion bonding is supported by a preponderance of the evidence (Ans. 10). 5 Appeal2014-005702 Application 11/150,879 Appellants have not directed our attention to any persuasive reasoning or adequate evidence to establish that the Examiner's determination is unreasonable. Nor have Appellants identified any definition or disclosure in the Specification that would establish that Hayasaka does not encompass the disputed limitations in claims 11 and 14. Furthermore, Appellants have not adduced any persuasive technical reasoning or evidence in response to the Examiner's determination that the use of CMP and etchback as exemplified by Hayasaka for wafer preparation with the thermal diffusion bonding method of Leedy and its wafer thinning techniques would have been prima facie obvious, as such a combination appears to be the use of known prior art elements according to their established functions (see, generally Ans.; Br.). KSR Int'! Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007) ("The combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results."). Under the flexible inquiry set forth by the Supreme Court, the PTO must take account of the "inferences and creative steps," or even routine steps, that an ordinary artisan would employ. Ball Aerosol and Specialty Container, Inc. v. Limited Brands, Inc., 555 F.3d 984, 993 (Fed. Cir. 2009). It is well settled that a reference stands for all of the specific teachings thereof as well as the inferences one of ordinary skill in this art would have reasonably been expected to draw therefrom. See Fritch, 972 F.2d 1264---65. In light of these principles and the tenets of claim interpretation, a preponderance of the evidence also supports the Examiner's rejections of the various claims argued separately (see, e.g., Ans. 9-17). Appellants have not shown any error in the Examiner's determination that the wafer thinning, 6 Appeal2014-005702 Application 11/150,879 vias, etchback process and bonding methods of Hayasaka are reasonably encompassed by the claimed method of preparing wafers (e.g., claims 11, 13, and 14) since no degree of flatness for the planar wafer surface is specified by the claim language. Regarding claim 14, the Appellants argue that the combination of references do not teach thinning a chip after the chip has been bonded to another chip. The argument is not commensurate with the scope of the claim as written. The claim is not explicit about the order of the steps of the process regarding second wafer thinning. "A person of ordinary skill is also a person of ordinary creativity, not an automaton." KSR, 550 U.S. at 421. It is incumbent upon Appellants to establish that more than routine experimentation is necessary to configure such a known method as depicted in Hayasaka to include the various features suggested by the secondary references applied by the Examiner. However, no such evidence is of record. Appellants have not provided any persuasive technical reasoning or evidence that it would have required more than ordinary creativity to form the recited method of thinning of wafers in preparation for thermal bonding. Appellants at most have provided mere attorney argument to that effect, and such arguments of counsel cannot take the place of evidence. See In re De Blauwe, 736 F.2d 699, 705 (Fed. Cir. 1984); In re Payne, 606 F.2d 303, 315 (CCP A 1979). A preponderance of the evidence also supports the Examiner's rejections of dependent claims 12, 15, and 16. Appellants' argument regarding dependent claims 12 and 15 that Hayasaka does not teach or suggest W (tungsten) is suitable for use in the method of Hayasaka as an etch stop (Br. 9) is not persuasive for reasons set out by the Examiner (Ans. 7 Appeal2014-005702 Application 11/150,879 16). Hayasaka also teaches the use of W as a film wherein the film is removed by means of CMP, etchback or the like (Hayasaka, col. 12, 11. 55- 63). Likewise, Appellants' argument regarding dependent claim 16 that Hayasaka in further view of Huang does not teach fiduciary marks is unavailing (Br. 1 O; Ans. 16). Huang teaches fiduciary marks in Fig. 1 as depicted as drawing item 210 comprising bumps 21 (Final Rej. 6). Therefore, we affirm the Examiner's § 103 rejections of all the claims on appeal. No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136. ORDER AFFIRMED 8 Copy with citationCopy as parenthetical citation