Ex Parte Hwang

Patent Trial and Appeal BoardSep 26, 2012

11026182 (P.T.A.B. Sep. 26, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE 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. 11/026,182 12/29/2004 Joon Hwang OPP-GZ-2004-0097-US-00 5650 36872 7590 09/27/2012 THE LAW OFFICES OF ANDREW D. FORTNEY, PH.D., P.C. 1725 N FINE AVE SUITE 101 FRESNO, CA 93727 EXAMINER POMPEY, RON EVERETT ART UNIT PAPER NUMBER 2812 MAIL DATE DELIVERY MODE 09/27/2012 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 JOON HWANG _____________ Appeal 2010-000720 Application 11/026,182 Technology Center 2800 ______________ Before, MAHSHID D. SAADAT, DAVID M. KOHUT, and TREVOR JEFFERSON, Administrative Patent Judges. KOHUT, Administrative Patent Judge. DECISION ON APPEAL Appeal 2010-000720 Application 11/026,182 2 This is a decision on appeal under 35 U.S.C. § 134(a) of the final rejection of claims 4-7, 9, 10, 12, and 14-27.1 We have jurisdiction under 35 U.S.C. § 6(b). We affirm the Examiner’s rejection of these claims. INVENTION The invention is directed to a method for fabricating a complementary metal-oxide semiconductor (CMOS) image sensor. Abstract. Claim 4 is representative of the invention and is reproduced below: 4. A method for fabricating a complementary metal-oxide semiconductor (CMOS) image sensor, the method comprising: forming at least a first pad layer and a second pad layer on a p-type semiconductor substrate having an active area and a device dividing area defined thereon; removing portions of the first pad layer and the second pad layer on the device dividing area, so as to expose the p-type semiconductor substrate and selectively removing the exposed p-type semiconductor substrate, thereby forming a trench; injecting first p-type impurity ions using a tilted ion injection method on inner walls of the trench sufficiently to form a first p-type impurity area at an interface of a subsequently-formed photodiode and the device dividing area and to thereby prevent leakage in the subsequently-formed photodiode and/or enhance the light-receiving characteristics of the subsequently-formed photodiode; forming a device dividing insulating layer on an entire surface of the p-type semiconductor substrate so as to fill the trench; 1 Claims 1-3, 8, 11, and 13 were previously cancelled. Appeal 2010-000720 Application 11/026,182 3 removing the device dividing the insulating layer, so that the device dividing the insulating layer remains only in the trench, and removing the remaining second pad layer; injecting impurity ions through the first pad layer into the active area, thereby forming a well; removing the remaining first pad layer after forming the well; and injecting n-type impurity ions into a photodiode area, thereby forming the photodiode. REFERENCES Lin US 6,194,285 B1 Feb. 27, 2001 Wu US 6,605,506 B2 Aug. 12, 2003 REJECTION AT ISSUE Claims 4-7, 9, 10, 12, and 14-27 are rejected under 35 U.S.C. § 103(a) as being unpatentable over the combination of Appellant’s Admitted Prior Art (AAPA), Wu, and Lin.2 Ans. 3-8. ISSUES Did the Examiner err in finding that Appellant’s disclosed “BACKGROUND” section (referred to by the Examiner as AAPA) is prior art? 2 The Examiner’s statement of rejection included cancelled claims 11 and 13. As these claims are not under appeal, we have not included them in the statement of the rejection. Additionally, the Examiner’s statement of rejection excluded claims 25-27, but included them under the rejection. Thus, we have included them in the statement of the rejection. Appeal 2010-000720 Application 11/026,182 4 Did the Examiner err in finding that the combination of AAPA, Wu, and Lin teaches or suggests injecting first p-type impurity ions using a tilted ion injection method on inner walls of the trench sufficiently to form a first p-type impurity area at an interface of a subsequently-formed photodiode and/or enhance the light-receiving characteristics of the subsequently- formed photodiode? Did the Examiner err in finding it obvious to combine AAPA, Wu, and Lin? ANALYSIS Appellant makes the following groupings: Group I – Claims 26 and 27; Group II – Claims 4, 5, 9, 10, 12, 14,3 15, 16, 21, 22, 24, and 25; Group III – Claims 6, 7, and 19; Group IV – Claim 17; Group V – Claim 18; Group VI – Claims 20 and 23. App. Br. 14. Group I Appellant’s Specification includes a section titled “BACKGROUND.” Spec. 1. For the reasons set forth below, we must determine whether disclosures within the Specification and Appellant’s additional statements on the record can be reasonably interpreted as 3 Appellant has inadvertently left out claim 14 in the grouping of claims, but includes claim 14 in the STATUS OF CLAIMS. App. Br. 5. As claim 14 is dependent upon claim 4, we have included claim 14 in Group II. Appeal 2010-000720 Application 11/026,182 5 constituting an admission by Appellants that the BACKGROUND discussion is prior art. The BACKGROUND discussion describes the method of fabricating a CMOS image sensor. Spec. 5-8. This section refers to the method as being a “related art.” Spec. 5. This description discusses many of the steps claimed in claim 26.4 The section concludes by stating that “the related art CMOS image sensor and method for fabricating the same have . . . disadvantages.” Spec. 8. The subsequent DETAILED DESCRIPTION OF THE INVENTION section of Appellant’s Specification describes modifications to the related art process that would prevent the disadvantages. Spec. 9-15. Thus, the Specification implies that the related art CMOS image sensor fabrication process is not part of Appellant’s invention. Rather, the related art CMOS image sensor fabrication process constitutes prior art upon which Appellant’s method improves upon. See In re Preda, 401 F.2d 825, 826 (CCPA 1968) (noting that “in considering the disclosure of a reference, it is proper to take into account not only specific teachings of the reference but also the inferences which one skilled in the art would reasonably be expected to draw therefrom”). Additionally, Appellant has made additional statements during prosecution that supports this interpretation. See In re Lopresti, 333 F.2d 932, 934 (CCPA 1964) (holding that statements made in Appellant’s Appeal Brief constituted an admission that the invention of another was prior art). In particular, on page 8 of Applicant’s Amendment/Request for 4 Appellant selects claim 26 as representative of the group comprising claims 26 and 27. App. Br. 14; Reply Br. 2. Appeal 2010-000720 Application 11/026,182 6 Reconsideration After Non-Final Rejection, filed January 5, 2007, Appellants state Nonetheless, Applicant’s discussion of the background discloses technology generally considered to be conventional. As such, Applicant does not intend to claim subject matter disclosed in the discussion of the background of the present application. The present invention represents an improvement over the subject matter disclosed in the background discussion of the present application. See also Ans. 9. These facts strongly imply that the BACKGROUND section of Appellant’s Specification constitutes prior art. MPEP § 21295 states: A statement by an applicant in the specification or made during prosecution identifying the work of another as “prior art” is an admission . . . . . . . [T]he examiner must determine whether the subject matter identified as “prior art” is applicant’s own work, or the work of another. In the absence of another credible explanation, examiners should treat such subject matter as the work of another. Appellant argues that Appellant has never made a statement that the BACKGROUND discussion describes “work of another.” App. Br. 16. However, the Examiner correctly treated the BACKGROUND discussion as work of another because Appellant did not provide any explanation as to whether it was Appellant’s own invention. Ans. 9. Instead, Appellant indicates that “it is possible that Appellant’s Background Discussion describes an approach that Appellant took, but did not disclose to the public, before arriving at the present invention. Alternatively, it could have been an 5 MPEP § 2129 Admissions as Prior Art. Appeal 2010-000720 Application 11/026,182 7 approach that Appellant’s coworkers took and kept secret before the present invention.” App. Br. 18. These conclusory statements are nothing more than attorney argument, unsupported by factual evidence. Attorney’s arguments in a brief cannot take the place of evidence. In re Pearson, 494 F.2d 1399, 1405 (CCPA 1974). For the reasons stated supra, we agree with the Examiner that Appellant’s BACKGROUND section of the Specification is prior art. Appellant argues that, even if Appellant’s Background Discussion is considered prior art, the Background discussion and the cited references fail to teach or “suggest injecting first p-type impurity ions using a tilted ion injection method on inner walls of the trench sufficiently to form a first p- type impurity area at an interface of a subsequently-formed photodiode . . . and/or enhance the light-receiving characteristics of the subsequently- formed photodiode.” App. Br. 19-20. Specifically, Appellant argues that neither Wu nor Lin teaches a photodiode or tilt implantation to prevent current leakage. App. Br. 19-20. However, the Examiner only uses Wu to teach tilt angle implantation into the walls of a trench (Ans. 10) and Lin to teach “forming a well through a pad oxide” (Ans. 11). Additionally, Appellant’s argument that the Background discussion does not teach the disputed limitations is merely a restatement of the claim and an argument that it is not taught. App. Br. 20. See 37 C.F.R. § 41.37(c)(1)(vii) (“A statement which merely points out what a claim recites will not be considered an argument for separate patentability of the claim.”); In re Lovin, 652 F.3d 1349, 1357 (Fed. Cir. 2011) (“[W]e hold that the Board reasonably interpreted Rule 41.37 to require more substantive arguments in an appeal brief than a mere recitation of the claim elements and a naked Appeal 2010-000720 Application 11/026,182 8 assertion that the corresponding elements were not found in the prior art.”). Thus, we do not find Appellant’s arguments to be persuasive. Appellant also argues that the motivation to combine the references is based on hindsight reasoning. App. Br. 22. We disagree and add the following for emphasis. First, as explained in In re McLaughlin: Any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning, but so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made and does not include knowledge gleaned only from applicant’s disclosure, such a reconstruction is proper. In re McLaughlin, 443 F.2d 1392, 1395 (CCPA 1971). Our review of the record establishes that the Examiner’s case for obviousness is only based on knowledge which was within the level of ordinary skill at the time of the Appellant’s invention and does not include knowledge gleaned only from the Appellant’s disclosure. Second, the Examiner identifies the relevant portions of each of the references relied on throughout the Examiner’s Answer. See Ans. 3-8. To the extent that the Examiner relies on the knowledge of one of ordinary skill in the art to combine the teachings of the references, this practice is consistent with current case law. For example, the Supreme Court explains: Often, it will be necessary for a court to look to interrelated teachings of multiple patents; the effects of demands known to the design community or present in the marketplace; and the background knowledge possessed by a person having ordinary skill in the art, all in order to determine whether there was an apparent reason to combine the known elements in the fashion claimed by the patent at issue. To facilitate review, this analysis should be made explicit. See In re Kahn, 441 F.3d 977, 988 (C.A.Fed.2006) (“[R]ejections on obviousness Appeal 2010-000720 Application 11/026,182 9 grounds cannot be sustained by mere conclusory statements; instead, there must be some articulated reasoning with some rational underpinning to support the legal conclusion of obviousness”). As our precedents make clear, however, the analysis need not seek out precise teachings directed to the specific subject matter of the challenged claim, for a court can take account of the inferences and creative steps that a person of ordinary skill in the art would employ. KSR Int’l Co, v. Teleflex, Inc., 550 U.S. 398, 418 (2007). In this case, the Examiner’s conclusions of obviousness are clearly articulated and are based on detailed factual findings that are supported by the references of record. See Ans. 3-8. Thus, we agree with the Examiner’s findings and conclusions. Lastly, Appellant argues that the invention creates unexpected results because it would not have been obvious to combine the references. App. Br. 26. As indicated above, we agree with the Examiner that the combination of the references is obvious. Thus, this argument is not persuasive. Appellant also argues that the Hwang Declaration, paragraphs 12-15, explains that claim 26 provides unexpected results. App. Br. 24. However, the cited portion of the Hwang Declaration merely indicates the disadvantages of the Background section, not the unexpected results of the invention. Additionally, paragraph 6 of the Hwang Declaration describes benefits to using the process described by claim 26. However, neither the Specification nor the Declaration actually states that these benefits, i.e., results, were unexpected. Cf. In re Soni, 54 F.3d 746, 751 (Fed. Cir. 1995) (“[W]hen an applicant demonstrates substantially improved results . . . and states that the results were unexpected, this should suffice to establish unexpected results in the absence of evidence to the contrary.”). Here, the only characterization of the results as unexpected is in the Appeal Brief, and Appeal 2010-000720 Application 11/026,182 10 attorney argument is not evidence. Additionally, no evidence in the form of test results was presented to compare the device performance and establish the results were in any way unexpected. Thus, the record is devoid of evidence showing that the benefits in the Hwang Declaration would not have been expected. For the reasons discussed supra, we sustain the Examiner’s rejection of claims 26 and 27. Groups II-VI Regarding Groups II-VI, Appellant makes the same arguments with respect to claim 26 and additionally restates the limitations of the representative claim and argues that the references fail to teach or suggest those limitations. App. Br. 26-31; Reply Br. 6. As noted above, these conclusory statements will not be considered arguments for separate patentability of the claim. See 37 C.F.R. § 41.37(c)(1)(vii). Therefore, we sustain the Examiner’s rejection of the claims grouped in Groups II-VI for the same reasons discussed supra with respect to claim 26. CONCLUSIONS The Examiner did not err in finding that Appellant’s disclosed “BACKGROUND” section is prior art. The Examiner did not err in finding that the combination of AAPA, Wu, and Lin teaches or suggests injecting first p-type impurity ions using a tilted ion injection method on inner walls of the trench sufficiently to form a first p-type impurity area at an interface of a subsequently-formed photodiode and/or enhance the light-receiving characteristics of the subsequently-formed photodiode. Appeal 2010-000720 Application 11/026,182 11 The Examiner did not err in finding it obvious to combine AAPA, Wu, and Lin. SUMMARY The Examiner’s decision to reject claims 4-7, 9, 10, 12, and 14-27 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). AFFIRMED msc