`Trials@uspto.gov
`Tel: 571-272-7822
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` Paper 11
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` Entered: April 30, 2013
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`UNITED STATES PATENT AND TRADEMARK OFFICE
`_______________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`_______________
`
`INNOLUX CORPORATION1
`Petitioner
`
`v.
`
`SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
`Patent Owner
`_______________
`
`Case IPR2013-00065(SCM)
`Patent 7,923,311 B2
`_______________
`
`
`Before SALLY C. MEDLEY, KARL D. EASTHOM, and
`KEVIN F. TURNER, Administrative Patent Judges.
`
`TURNER, Administrative Patent Judge.
`
`
`DECISION
`Institution of Inter Partes Review
`37 C.F.R. § 42.108
`
`
`
`
`1
` See Paper No. 10 (Petitioner’s Mandatory Notice updating the Board as to
`its name change from “Chi Mei Innolux Corporation,” which Petitioner also
`refers to as “formerly Cheimei Innolux Corporation,” to “Innolux
`Corporation” as the real party-in-interest in this proceeding). The caption, as
`it appears above, will be employed in all future correspondence.
`
`

`

`Case IPR2013-00065
`Patent 7,923,311 B2
`
`
`I. BACKGROUND
`
`Petitioner, Chimei Innolux Corp. (“CMI”)2, filed a Petition3 to institute an
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`inter partes review of claims 23, 24, 26-40, 42-44, 46, 49, 50, 53, and 54 of
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`U.S. Patent 7,923,311 B2 (“the '311 Patent”)4 owned by Semiconductor Energy
`
`Laboratory Co., Ltd. (“SEL”). See 35 U.S.C. § 311. In response, Patent Owner,
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`SEL, filed a Preliminary Response.5 The standard for instituting an inter partes
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`review is set forth in 35 U.S.C. § 314(a):
`
`THRESHOLD – The Director may not authorize an inter partes
`review to be instituted unless the Director determines that the
`information presented in the petition filed under section 311 and any
`response filed under section 313 shows that there is a reasonable
`likelihood that the petitioner would prevail with respect to at least 1 of
`the claims challenged in the petition.
`
`Pursuant to the defined threshold under 35 U.S.C. § 314(a), the Board
`
`institutes an inter partes review of claims 23, 24, 26-40, 42-44, 46, 49, 50, 53, and
`
`54 of the '311 Patent.6
`
`
`
`A. The '311Patent
`
`The '311 Patent describes a thin film transistor (TFT) and a method for
`
`forming the same (EX 1001, col. 1, ll. 7-10). According to the '311 Patent,
`
`numerous problems were associated with prior art methods of crystalizing
`
`2 While we acknowledge the name change of Petitioner (see footnote 1), we
`continue to refer to that party as “CMI” for purposes of this Decision.
`3 Petition for Inter Partes Review of U.S. Patent No. 7,923,311 Under 35 U.S.C.
`§§ 311-319 and 37 C.F.R. § 42.100 Et Seq. (Nov. 26, 2012).
`4 Based on a terminal disclaimer filed during the prosecution of the application for
`the '311 Patent, the patent has now expired (Pet. 5, 8).
`5 Patent Owner Preliminary Response Under 37 C.F.R. § 42.107 (Feb.2 6, 2013).
`6 A second request for inter partes review of claims 9-11, 15, 17-19, 48, 51, and 52
`of the '311 Patent was filed concurrently with the instant Petition (IPR 2013-
`00064), where a Decision on that petition is being sent out concurrently.
`
`
`
`2
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`Case IPR2013-00065
`Patent 7,923,311 B2
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`amorphous silicon layers used in devices (Id. at col. 1, ll. 14-44). According to the
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`disclosure of the '311 Patent, the later crystallization by laser irradiation of
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`semiconductor materials in the channel region and the activation of the ohmic
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`contact region of the source and drain provides improvements in electrical
`
`conductivity and avoids the prior art problems (Id. at col. 1, l. 52 - col. 2, l. 4).
`
`Figures 3(D) and 3(F), which follow, illustrate portions of the method used
`
`to fabricate the TFT:
`
`
`
`A metal layer is deposited on a silicon dioxide layer on a glass substrate and
`
`patterned to form a gate electrode, with a gate insulating film, a first semiconductor
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`film, and an N-type semiconductor film deposited thereon (Id. at col. 5, l. 55 –
`
`col. 6, l. 43). A photoresist (P2) is used to pattern those layers to form a TFT
`
`island (Id. at col. 6, ll. 44-52; Fig. 3(D)). A conductive layer is deposited on the
`
`TFT island, with a photoresist (8, P3) applied thereon (Id. at col. 6, ll. 53-62;
`
`Fig. 3(F)). Source and drain electrodes (9 & 10) are formed by etching of the
`
`conductive layer, using the photoresist (P3), with source and drain regions (11 &
`
`12) being formed from the N-type semiconductor film by the same etching process
`
`(Id.).
`
`
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`3
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`Case IPR2013-00065
`Patent 7,923,311 B2
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`
`In one embodiment, a wet etching process may be applied to the structure as
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`illustrated in Figure 3(F) so that the distance between the source and drain regions
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`(11 & 12), in the channel region, is less than the distance between the source and
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`drain electrodes (9 & 10), as illustrated in Figure 3(G):
`
`Thereafter, a passivation film is applied to cover the source and drain
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`electrodes, the source and drain regions, and the channel formation region (Id. at
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`col. 7, ll. 1-9; Fig. 3(H)). In addition, pixel electrodes may be formed over the
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`passivation film, which may form an electrical connection to the source or drain
`
`
`
`electrode (Id. at col. 7, ll. 50-53).
`
`
`
`B. Illustrative Claim
`
`Illustrative claim 23 follows, with emphasis applied:
`
`23. A method of manufacturing a display device including a
`thin film transistor over a glass substrate, the method comprising the
`steps of:
`
`forming a resist on a conductive layer wherein said conductive
`layer is formed on an N-type semiconductor film, said N-type
`semiconductor film is formed on a first semiconductor film, and said
`first semiconductor film is formed over a gate electrode with a gate
`insulating film comprising silicon nitride interposed therebetween;
`
`etching a portion of said conductive layer to form source and
`drain electrodes using said resist;
`
`etching a portion of said N-type semiconductor film to form
`source and drain regions without removing said resist wherein a
`channel forming region is formed in said first semiconductor film
`between said source and drain regions; and
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`
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`4
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`

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`Case IPR2013-00065
`Patent 7,923,311 B2
`
`
`forming a passivation film over at least said source and drain
`electrodes and said channel forming region after removing said resist,
`
`wherein each of the source and drain regions has a bottom
`surface in contact with the first semiconductor film, each of the source
`and drain electrodes has a bottom surface in contact with
`corresponding one of the source and drain regions, and the
`conductive layer is overetched using said resist so that a distance
`between opposed ends of the bottom surfaces of the source and drain
`electrodes is larger than a distance between opposed ends of the
`bottom surfaces of the source and drain regions.
`
`
`
`C. Related Proceedings
`
`The '311 Patent is involved with several other related CMI patents in several
`
`other inter partes review filings before the PTAB, and also in infringement
`
`litigation styled as Semiconductor Energy Laboratory Co., Ltd. v. Chimei Innolux
`
`Corp., et al., SACV12-0021-JST (C.D. Cal.) (filed Jan. 5, 2012) [hereinafter the
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`CMI Case]. (See Pet. 1-2; Prelim. Resp. 4). Defendants in that case filed a motion
`
`on October 22, 2012 to stay that litigation pending the outcome of this instant
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`proceeding (EX 2002), where that request for a stay was granted on
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`December 19, 2012.
`
`CMI also discusses the prosecution, litigation, and reexamination of related
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`U.S. Patent No. 6,756,258 (EX 1010, “the '258 Patent”), where the '258 Patent
`
`claims priority to the same Japanese patent application (JP 03-174541) that the
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`instant '311 Patent does (Pet. 9).
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`5
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`Case IPR2013-00065
`Patent 7,923,311 B2
`
`
`CMI relies upon the following prior art references:
`
`D. Prior Art Relied Upon
`
`U.S. Patent 5,198,694
`U.S. Patent 5,270,567
`JP Patent Pub. 01-144682
`JP Patent Pub. 01-180523
`JP Patent Pub. 02-234125
`
`Mar. 30, 1993
`Dec. 14, 1993
`Jun. 6, 1989
`Jul. 18, 1989
`Sep. 17, 1990
`
`Kwasnick
`Mori
`Noguchi
`Matsuzaki
`Taniguchi
`
`Peter Van Zant, Microchip Fabrication: A Practical Guide to Semiconductor
`Processing, pp. 221-228 and 298 (2nd ed. 1990) (“Van Zant,” EX 1009).
`
`
`(EX 1008)
`(EX 1003)
`(EX 1002)
`(EX 1007)
`(EX 1006)
`
`E. The Asserted Grounds
`
`CMI asserts the following obviousness grounds of unpatentability under
`
`35 U.S.C. § 103:
`
`Claims 23, 24, 26-40, 42-44, 46, 49, 50, 53, and 54 over:
`
`i)
`
`Taniguichi, Mori, and Van Zant, or
`
`ii) Matsuzaki, Mori, and Van Zant; and
`
`Claims 23, 24, 26-28, 30-32, 34-36, 38-40, 42-44, 46, 49, 50, 53, and 54
`
`over Noguchi, Mori, and Van Zant; and
`
`Claims 29, 33, and 37 over Noguchi, Mori, Kwasnick, and Van Zant.
`
`(Pet. 4-5).
`
`
`
`II. ANALYSIS
`
`A. Threshold Issues
`
`1. Prosecution History of the '311 Patent
`
`SEL contends that CMI’s Petition for Inter Partes Review of the '311 Patent
`
`is improper under 35 U.S.C. § 325(d) because during prosecution of the application
`
`leading to the '311 Patent, the PTO examiner who allowed the '311 Patent to issue
`
`previously considered all of the same prior art references under consideration here,
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`in that they were all submitted by the patentee in an information disclosure
`
`statement (See Prelim. Resp. 9-10).
`
`That the documents were considered as prior art listed in the prosecution
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`record of the '311 Patent application is a factor which the Board “may take into
`
`account” according to 35 U.S.C. § 325(d). However, SEL does not show that the
`
`examiner of the '311 Patent application considered “substantially the same . . .
`
`arguments,” as CMI presents here, another factor which the Board “may take into
`
`account” according to 35 U.S.C. § 325(d).
`
`Absent a showing of “substantially the same . . . arguments,” id., and
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`considering that CMI includes evidence not considered before the '311 Patent
`
`examiner, including Kato, even if cumulative as alleged, and the declaration of
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`Jerzy Kanicki, Ph.D. (“Kanicki Decl.”) (Ex. 1014), SEL does not show that the
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`inter partes review of the '311 Patent would be improper under 35 U.S.C. § 325(d).
`
`
`
`2. Real Parties-In-Interest
`
`SEL also contends that this review should be denied because the Petition
`
`fails to identify all of the real parties-in-interest as required by 35 U.S.C.
`
`§ 312 (a)(2) and 37 C.F.R. § 42.8(b)(1) (Prelim. Resp. 2-9). The Trial Practice
`
`Guide provides guidance regarding factors to consider in determining whether a
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`party is a real party-in-interest. As SEL acknowledges, a primary consideration
`
`includes whether a non-party exercises control over a petitioner’s participation in a
`
`proceeding. (See Prelim. Resp. 2-3, citing Office Patent Trial Practice Guide,
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`77 Fed. Reg. 48756, 48759 (August 14, 2012)). Other considerations may include
`
`whether a non-party, in conjunction with control, funds the proceeding and directs
`
`the proceeding (Trial Practice Guide at 60).
`
`
`
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`
`SEL asserts that co-defendants with CMI, “CMO USA,” “Acer America,”
`
`“ViewSonic,” “VIZIO,” and “Westinghouse”, in the pending CMI Case (see supra
`
`§ IC), represented to the district court that the co-defendants all participated in
`
`filing the instant Petition in support of a district court motion to stay, and that the
`
`co-defendants all agreed to be bound by the Inter Partes Review (See Prelim.
`
`Resp. 3-9). SEL focuses on statements to the district court in which the co-
`
`defendants refer to “‘their’” Petition which “‘Defendants have moved
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`expeditiously to prepare and file.’” (Prelim. Resp. 4 (quoting the co-defendants
`
`in the CMI Case, emphasis by SEL)).
`
`Notwithstanding SEL’s assertions, SEL does not set forth persuasive
`
`evidence that the district court co-defendants CMO USA, Acer America,
`
`ViewSonic, VIZIO, and Westinghouse necessarily have any control over this
`
`proceeding. The statements that SEL refer to do not show that these other co-
`
`defendants had control over the Petition, or will exert control over the proceeding.
`
`The statements made in connection with the joint motion to stay may have been a
`
`short-hand explanation (e.g., speaking as one unified voice as opposed to
`
`explaining in great length who controlled the contents of the Petition, etc.) to the
`
`district court of the events leading up to the filing of the instant Petition. Toward
`
`that end, only lead counsel for CMI, Scott A. McKeown, signed the Petition (see
`
`Pet. 5, 60), which “certifies that CMI is the real party-in-interest” (Pet. 1).
`
`Accordingly, the collective filing of a motion to stay and other assertions do not
`
`prove control by each party.
`
`As indicated, SEL has not shown, for example, that the co-defendants CMO
`
`USA, Acer America, ViewSonic, VIZIO, and Westinghouse necessarily co-
`
`authored the Petition or exerted control over its contents, or will exert any control
`
`over the remaining portions of this proceeding. SEL has failed to provide
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`
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`Case IPR2013-00065
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`persuasive evidence that each of the co-defendants in the CMI Case provided
`
`funding for the instant Petition, let alone exercised control and funding. That the
`
`co-defendants agree to be bound by the decision of this Inter Partes Review
`
`insofar as the co-pending litigation is concerned does not dictate that each of the
`
`co-defendants are real parties-in-interest in this proceeding. Accordingly, SEL has
`
`not demonstrated that CMI has failed to list all the real parties-in-interest under
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`35 U.S.C. § 312 (a)(2) and 37 C.F.R. § 42.8(b).
`
`
`
`3. Claims of the '258 Patent
`
`CMI discusses the disposition of the '258 Patent, where the '258 Patent
`
`claims priority to the same Japanese patent application as the instant '311 Patent
`
`(see supra § IC). That litigation and an inter partes reexamination (95/00,246)
`
`resulted in the invalidation or cancellation of many of the claims of the '258 Patent
`
`(Pet. 9). CMI also alleges that the contested claims of the '311 Patent are obvious
`
`variants of claims surrendered or cancelled of the '258 Patent, and provides a
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`comparison chart of claims in both (Pet. 9-12). Because of this, CMI also alleges
`
`“that administrative estoppel prevents the presentation of arguments that are
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`inconsistent with the results of the previous USPTO proceeding” (Pet. 16-18).
`
`SEL argues that CMI is incorrect because i) the claims of the '311 Patent are
`
`patently distinct from the cancelled claims in the '258 Patent, and ii) CMI has
`
`misapplied “interference” estoppel to the claims of the '258 Patent (Prelim. Resp.
`
`14-18). We need not reach the second contention as we concur with SEL that CMI
`
`has not persuasively shown that the claims are patentably indistinct.
`
`As provided in CMI comparison chart (Pet. 10-12), claim 27 of the
`
`'311 Patent details that the etching is performed “without removing said resist.”
`
`Claim 5 of the '258 Patent, cited for comparison, only provides for an “etching”
`
`
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`9
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`step, without recitation that the resist remains in place. While CMI alleges that “in
`
`the context of the common patent specification there is no difference between the
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`claim terms” (Pet. 17), CMI has not persuaded us that the differences between the
`
`claims, such as that cited supra, render those claims patentably indistinct. See
`
`McCabe v. Cramblet, 65 F.2d 459, 461-462 (C.C.P.A. 1933). While the
`
`representative claims may recite similar limitations, CMI has not persuasively
`
`shown that the claims necessarily call for the same invention. Given this, we
`
`conclude that no estoppel should necessarily attach to the instant claims of the
`
`'311 Patent based on the surrender or cancellation of claims of the '258 Patent.
`
`
`
`B. Claim Construction
`
`The Board’s review of the claims of an expired patent is similar to that of a
`
`district court’s review. In re Rambus, Inc., 694 F.3d 42, 46 (Fed. Cir. 2012). The
`
`principle set forth by the court in Phillips v. AWH Corp., 415 F.3d 1303, 1316,
`
`1327 (Fed. Cir. 2005) (words of a claim “are generally given their ordinary and
`
`customary meaning” as understood by a person of ordinary skill in the art in
`
`question at the time of the invention, construing to preserve validity in case of
`
`ambiguity) should be applied since the expired claims are not subject to
`
`amendment. CMI submits that none of the claim terms contain means-plus-
`
`function or step-plus-function limitations, or appear to recite coined or
`
`lexicographical phrases requiring special consideration (Pet. 5), and SEL does not
`
`appear to contradict this in their Preliminary Response.
`
`CMI also points out that a district court has construed the same or similar
`
`claim terms in litigation involving the '258 Patent (Pet. 5-6), and provides
`
`Judge Patel’s March 27, 2006, claim construction order (EX 1015). In particular,
`
`CMI directs attention to the judge’s order regarding the term “overetching.” We
`
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`have reviewed the district court’s claim construction (EX 1015 pp. 3, 4) for the
`
`term “overetching” and hold that CMI has shown that that claim interpretation is
`
`consistent with the ordinary and customary meaning as understood by one of
`
`ordinary skill in the art. Accordingly, we agree with the district court that
`
`overetching can be performed either as a separate step, involving the application of
`
`additional etchant, or by extending the original etching such that the etchant
`
`undercuts the mask.
`
`
`
`C. Asserted Grounds of Unpatentability
`
`A patent claim is unpatentable under 35 U.S.C. § 103(a) if the differences
`
`between the claimed subject matter 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).
`
`In making the threshold determination under 35 U.S.C. § 314(a), the Board
`
`considers CMI’s Petition and SEL’s Preliminary Response, and in addition, the
`
`prior art and relevant expert report submissions.
`
`
`
`Taniguichi, Mori, and Van Zant
`
`CMI relies on the Kanicki Declaration (EX 1014), Taniguchi (EX 1006),
`
`Mori (EX 1003), and Van Zant (EX 1009) to set forth its obviousness challenge to
`
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`Case IPR2013-00065
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`
`the claims 23, 24, 26-40, 42-44, 46, 49, 50, 53, and 54 (See Pet. 18-22, 30-32, 37-
`
`40, 45-46, 49-52, 57-58). In response, SEL focuses attention on independent
`
`claim 23 through two major contentions, namely that Taniguchi and Mori fail to
`
`disclose element (j) of claim 23 and that there is no motivation to combine
`
`Taniguchi and Mori (Prelim. Resp. 18-30)7. We address SEL’s contentions as we
`
`set forth our determination that CMI has persuaded us that it has met the required
`
`showing on the unpatentability of claim 23 for this stage of the proceeding.
`
`CMI shows persuasively that Taniguchi discloses the process of forming a
`
`TFT on a glass substrate (SUB1), having a gate electrode (GT) formed thereon,
`
`with subsequent deposition of an insulating film (GI) composed of silicon nitride,
`
`an i-type amorphous silicon layer, and an N+-type silicon film (See Pet. 18-19;
`
`EX 1006, pp. 2, 5, 22; Fig. 22). Thereafter, both semiconductor layers are etched
`
`selectively using a photoresist to form the source and drain regions, and multiple
`
`metal layers are produced by sputtering and selectively etched to form the source
`
`and drain electrodes, resulting in the step-like structure illustrated in Figure 22 (See
`
`Pet. 19-20; EX 1006, p. 22; Fig. 22). The Kanicki Declaration (EX 1014) provides
`
`that Taniguchi discloses that the i-type semiconductor layer (AS) is used as the
`
`respective channel formation area for the TFT (Kanicki Decl. ¶ 62), and Taniguchi
`
`discloses a protection film (PSV 1) that is formed over the channel, source and
`
`drain regions, and electrodes (See Pet. 24; EX 1006, p. 23; Fig. 22).
`
`Figure 22, as annotated by CMI, is reproduced below:
`
`
`7 While SEL follows the structure of the Petition, breaking the subject claims into
`many subgroups, SEL’s arguments (Prelim. Resp. 39, 41-43, 46-47, 57-58) are
`substantially the same as those discussed with respect to claim 23. SEL’s
`arguments with respect to claims 39, 40, 42, and 49 include additional contentions
`and are addressed separately below.
`
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`
`Although CMI contends that Taniguchi illustrates that a distance between
`
`opposed ends of the bottom surfaces of the source and drain electrodes is larger
`
`than a distance between opposed ends of the bottom surfaces of the source and
`
`drain (Pet. 20-21),8 CMI also cites Mori (EX 1003), Figure 12 of which is provided
`
`below, as annotated by CMI:
`
`
`
`
`
`CMI details that Mori discloses the above step-like structure, with the
`
`distance between opposed ends of the source and drain electrodes (36 & 37) being
`
`greater than the distance between the opposed ends of the source and drain regions
`
`(35) (EX 1003, col. 1, l. 50 – col. 2, l. 22; Fig. 12). Mori discloses that the step-
`
`like structure reduces the gate-to-source and gate-to-drain capacitance problems
`
`
`8 Where Dr. Kanicki agrees with this proposition (Kanicki Decl. ¶¶ 66-69).
`
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`present in other designs (Id. at col. 2, ll. 18-21). CMI argues that this known
`
`benefit would have provided motivation for ordinarily skilled artisans to provide
`
`such a structure in the TFT design of Taniguchi (Pet. 13-14). It is further clear,
`
`from Van Zant (EX 1009, pp. 222-23, 228), that overetching can be used to form
`
`specific stepped structures. This rationale is sufficient to combine Taniguchi,
`
`Mori, and Van Zant to meet the limitations of claim 23.
`
`SEL argues that the upper portions of the source and drain regions, d0, are
`
`aligned with the lowest portion of the source and drain electrodes, d1, such that
`
`Taniguchi does not meet the last limitation of claim 23, with its recitation of the
`
`distances between bottom surfaces (Prelim. Resp. 18-20). SEL also argues that
`
`Dr. Kanicki’s testimony ignores the presence of the d1 layer, that any stepped
`
`structure between d1 and d0 is not visible in Figure 22 of Taniguchi, and that one
`
`of ordinary skill in the art would not have perceived a step from a review of
`
`Taniguchi (Prelim. Resp. 20-23). Even accepting these positions to be correct, the
`
`specific deficiencies of Taniguchi are not fatal because the ground of
`
`unpatentability is raised with respect to both Taniguchi and Mori. References must
`
`not be read in isolation, but must be read for what they fairly teach in combination
`
`with the prior art as a whole. In re Merck & Co., Inc., 800 F.2d 1091, 1097 (Fed.
`
`Cir. 1986). As such, SEL’s argument is not persuasive.
`
`SEL also argues that there is no motivation to combine Taniguchi with Mori
`
`(Prelim. Resp. 23-26). SEL argues that Taniguchi teaches away from creating a
`
`step between the chromium layer d1 and the N-type semiconductor layer d0
`
`because the former acts as a barrier layer for the latter against aluminum diffusing
`
`from the aluminum layer d2 (Prelim. Resp. 23-24). SEL continues that any step
`
`between layers d1 and d0 would expose the N-type semiconductor layer and defeat
`
`the purpose of the chromium layer d1 (id.). However, depending on the step
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`created, the chromium layer d1 would still act as a barrier layer. We can find no
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`recitation in Taniguchi that the edges of the chromium layer d1 and the N-type
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`semiconductor layer d0 must be coincident. A step between the layers do and d1
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`would not create a diffusion path for aluminum from layer d2 during the formation
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`or operation of the transistor, as SEL has argued (id.). As such, we do not find any
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`specific teaching away or a teaching in Taniguchi that would contradict the
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`combination of Taniguchi with Mori and Van Zant. As such, SEL’s argument is
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`not persuasive.
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`SEL argues that any attempt to realize Mori’s objective of having no overlap
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`between the gate electrode and the source and drain electrodes, to reduce parasitic
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`capacitance, would render the TFT of Taniguchi disabled or unfit for its intended
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`purpose (Prelim. Resp. 24-26). If one of ordinary skill in the art would look to
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`Mori and see only the need to eliminate any overlap in the electrodes, then perhaps
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`SEL’s argument would be persuasive. However, “[c]ombining the teachings of
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`references does not involve an ability to combine their specific structures.” In re
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`Nievelt, 482 F.2d 965, 968 (CCPA 1973). “The test is what the combined
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`teachings of those references would have suggested to those of ordinary skill in the
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`art.” In re Keller, 642 F.2d 413, 425 (CCPA 1981). One of ordinary skill in the art
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`would have viewed Mori as teaching the reduction as well as the elimination of
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`parasitic capacitance. To that end, reducing the overlap of the gate electrode with
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`the source and drain electrodes would reduce parasitic capacitances therefrom.
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`While SEL discusses the endpoints of such a process, reducing the size of the gate
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`electrode or receding the source and drain electrodes to achieve zero overlap, such
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`considerations do not take into account the benefits of reducing instead of totally
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`eliminating overlap and thus parasitic capacitances. We conclude that one of
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`ordinary skill in the art would have viewed both elimination and reduction in the
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`overlap and the parasitic capacitance as suggestions from Mori, such that
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`Taniguchi would have been modified so that a distance between the source and
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`drain regions is shorter than a distance between the source and drain electrodes, per
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`claim 23. As such, SEL’s argument is not persuasive.
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`SEL also argues that there would be no need to combine Taniguchi with
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`Mori because Taniguchi already has solved the problem with which Mori is
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`concerned (Prelim. Resp. 26-27). Taniguchi discloses that increasing the size of
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`the gate electrode increases parasitic capacitance, but that the retention capacitance
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`element solves this problem (EX 1006, p. 16). We conclude, however, that SEL’s
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`argument improperly makes the good the enemy of the perfect. The fact that the
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`retention capacitance can compensate for the parasitic capacitance does not mean
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`that one of ordinary skill in the art would not also seek to reduce such a parasitic
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`capacitance. We do not take from the recitation in Taniguchi that “[t]he retention
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`capacitance element Cadd solves this problem as well” that ordinary skilled
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`artisans would have no concern about such parasitic capacitances. Rather, we
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`concur with CMI that one of ordinary skill in the art would have viewed the
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`reduction in parasitic capacitance from Mori as a benefit and would have sought to
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`incorporate aspects into the already stepped structure of Taniguchi to achieve the
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`same, at least to some degree. As such, SEL’s argument is not persuasive.
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`SEL also argues that it would be impossible to manufacture the TFT
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`disclosed in Mori, having a stepped structure, by using the method disclosed in
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`Taniguchi, which uses the same resist to etch the N-type semiconductor and first
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`conductive layers (Prelim. Resp. 28-30). However, the ground proffered by CMI
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`modifies Taniguchi in view of Mori, such that the efficacy of modifying Mori in
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`view of Taniguchi need not be considered. As such, SEL’s argument is not
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`persuasive.
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`As to claims 24 and 26, which depend from claim 23, CMI similarly relies
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`on Taniguichi, Mori, Van Zant, and the Kanicki Declaration, and shows
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`persuasively that the prior art combination teaches or renders obvious the
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`additional recited limitations in those claims (See Pet. 21-22). SEL’s arguments
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`are directed to representative claim 23, and SEL does not appear to contest the
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`specific limitations in the dependent claims with separate arguments (Prelim.
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`Resp. 18, 34). Thus, for the reasons discussed supra, we determine that the
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`Petition establishes a reasonable likelihood of prevailing on the above-cited ground
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`of unpatentability of claims 24 and 26.
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`With respect to independent claims 27, 31, 35, and 43, and subject claims
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`dependent thereon, CMI identifies differences between the recitations of claim 23
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`and those other claims, and argues that those different recitations are disclosed in
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`Taniguchi, buttressed by the Kanicki Declaration (Pet. 30-31, 37-40, 45-46, 57-
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`58). SEL does not appear to dispute these aspects of Taniguchi (Prelim. Resp. 39,
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`41-43, 46-47, 57-58). Therefore, based on the above analysis of claim 23, we
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`concur with CMI and determine that the Petition establishes a reasonable
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`likelihood of prevailing on the asserted ground of unpatentability of claims 27-38,
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`43, 44, 46, 50, 53, and 54 as obvious under 35 U.S.C. § 103 based on the
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`combination of Taniguichi, Mori, and Van Zant.
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`With respect to claims 39, 40, 42, and 49, CMI indicates that the preamble
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`and the first five elements of independent claim 39 are analogous to those
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`discussed above (Pet. 49-51). The last element of claim 39 recites that “a thickness
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`of the source and drain regions in at least part of the first portion is substantially
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`the same thickness of at least part of a second portion of each of the source and
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`drain regions covered by the source and drain electrodes.” CMI cites to figure 12
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`of Mori (EX 1003, Fig. 12) and the remarks of Dr. Kanicki (Kanicki Decl. ¶¶ 77-
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`80). The analysis of claims 40, 42, and 42 is asserted by CMI to be analogous to
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`that discussed above (Pet. 51-52).
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`SEL repeats the arguments made with respect to claim 23 against CMI’s
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`obviousness ground against claim 39 (Prelim. Resp. 49-50), but we do not find
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`those arguments to be any more persuasive against the proffered ground for
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`claims 39, 40, 42, and 49. With respect to the last element of claim 39, SEL also
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`points out that Dr. Kanicki’s statements do not provide that the cited N-type silicon
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`film (d0), of Taniguchi, has a first part or second part, or where those parts would
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`be located (Prelim. Resp. 52; Kanicki Decl. ¶ 77). However, SEL overlooks
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`Dr. Kanicki’s next paragraph (Kanicki Decl. ¶ 78), which discusses Fig. 12 of
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`Mori. We concur that it would have been obvious to have the thicknesses of all
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`parts of the source and drain regions be substantially the same, because they are
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`produced from the same deposited film. As such, SEL’s argument is not
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`persuasive.
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`Pursuant to the foregoing discussion, the Petition establishes a reasonable
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`likelihood of prevailing on the asserted ground of unpatentability of claims 23, 24,
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`26-40, 42-44, 46, 49, 50, 53, and 54 as obvious under 35 U.S.C. § 103 based on the
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`combination of Taniguichi, Mori, and Van Zant.
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`
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`Other Combinations
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`We determine that it is unnecessary to reach CMI’s asserted obviousness
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`grounds of unpatentability involving the combinations of Noguchi, Mori, and Van
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`Zant, Matsuzaki, and Zwasnick, in light of the determination that there is a
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`reasonable likelihood that claims 23, 24, 26-40, 42-44, 46, 49, 50, 53, and 54 are
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`unpatentable based on the ground on which we institute an inter partes review.
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`We therefore exercise our discretion to deny these grounds as redundant. See
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`37 C.F.R. § 42.208.
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`
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`III. SUMMARY
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`For the forgoing reasons, we determine that the information presented in
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`CMI’s petition shows that there is a reasonable likelihood that CMI would prevail
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`with respect to claims 23, 24, 26-40, 42-44, 46, 49, 50, 53, and 54 of the
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`'311