Trials@uspto.gov
`571-272-7822
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`Paper 11
`Entered: June 8, 2016
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`UNITED STATES PATENT AND TRADEMARK OFFICE
`____________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`____________
`
`INTEL CORPORATION,
`Petitioner,
`
`v.
`
`DSS TECHNOLOGY MANAGEMENT, INC.,
`Patent Owner.
`____________
`
`Case IPR2016-00288
`Patent 6,784,552 B2
`
`Before BRYAN F. MOORE, BRIAN J. McNAMARA, and
`MINN CHUNG, Administrative Patent Judges.
`
`CHUNG, Administrative Patent Judge.
`
`
`
`
`DECISION
`Institution of Inter Partes Review
`37 C.F.R. § 42.108
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`571-272-7822
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`Paper 11
`Entered: June 8, 2016
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`____________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`____________
`
`INTEL CORPORATION,
`Petitioner,
`
`v.
`
`DSS TECHNOLOGY MANAGEMENT, INC.,
`Patent Owner.
`____________
`
`Case IPR2016-00288
`Patent 6,784,552 B2
`
`Before BRYAN F. MOORE, BRIAN J. McNAMARA, and
`MINN CHUNG, Administrative Patent Judges.
`
`CHUNG, Administrative Patent Judge.
`
`
`
`
`DECISION
`Institution of Inter Partes Review
`37 C.F.R. § 42.108
`
`
`
`
`
`
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`I. INTRODUCTION
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`IPR2016-00288
`Patent 6,784,552 B2
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`Intel Corporation (“Petitioner”) filed a Petition (Paper 2, “Pet.”)
`requesting an inter partes review of claims 8–12 (the “challenged claims”)
`of U.S. Patent No. 6,784,552 B2 (Ex. 1101, “the ’552 patent”). DSS
`Technology Management, Inc. (“Patent Owner”) filed a Preliminary
`Response (Paper 7, “Prelim. Resp.”). We have jurisdiction under 35 U.S.C.
`§ 314.
`The standard for instituting an inter partes review is set forth in
`35 U.S.C. § 314(a), which provides that an inter partes review may not be
`instituted “unless the Director determines . . . there is a reasonable likelihood
`that the petitioner would prevail with respect to at least 1 of the claims
`challenged in the petition.” For the reasons described below, we determine
`that Petitioner has established a reasonable likelihood of prevailing in
`showing the unpatentability of claims 8–12. Accordingly, we institute an
`inter partes review of claims 8–12 of the ’552 patent.
`
`A. Related Proceedings
`According to the parties, the ’552 patent is the subject of the
`following patent infringement cases: DSS Tech. Mgmt., Inc. v. Intel Corp. et
`al., Case No. 6:15-cv-130-JRG (E.D. Tex.); DSS Tech. Mgmt., Inc. v.
`Samsung Elec. Co., Ltd. et al., Case No. 6:15-cv-690 (E.D. Tex.); DSS Tech.
`Mgmt., Inc. v. SK Hynix, Inc., et al., Case No. 6:15-cv-691 (E.D. Tex.); and
`DSS Tech. Mgmt., Inc. v. Qualcomm, Inc., Case No. 6:15-cv-692 (E.D.
`Tex.). Pet. 7; Paper 6, 2–3. The ’552 patent is also the subject of a co-
`pending petition for inter partes review filed by Petitioner (Intel Corp. v.
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`DSS Tech. Mgmt., Inc., Case IPR2016-00287, Paper 2) as well as an
`instituted trial proceeding SK Hynix, Inc. v. DSS Tech. Mgmt., Inc., Case
`IPR2016-00192. Petitioner also filed petitions seeking inter partes review
`of claims of U.S. Patent No. 5,965,924 in Intel Corp. v. DSS Tech. Mgmt.,
`Inc., Cases IPR2016-00289 and IPR2016-00290. Pet. 7; Paper 6, 3.
`
`B. The ’552 Patent
`The ’552 patent describes a process of semiconductor device
`fabrication and a structure of a semiconductor device having “substantially
`rectangular” lateral insulating spacers adjacent to gate electrodes. Ex. 1101,
`Abstract. The ’552 patent defines the term “substantially rectangular” to
`mean that “a side of the spacer has an angle relative to the substrate surface
`of more than 85°.” Id. at col. 8, ll. 40–42. Figure 4(D) of the ’552 patent is
`reproduced below.
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`Figure 4(D) illustrates a cross-sectional view of a series of gates 415 (also
`called conducting layers or polysilicon layers) completely encapsulated in
`insulating material 420, e.g., TEOS (tetraethyl orthosilicate glass), where
`spacers 435 of the insulating material adjacent to the gates have substantially
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`rectangular profiles. Id. at col. 9, ll. 9–13; col. 11, ll. 40–46. As shown in
`Figure 4(D), gates 415 are insulated from sources or drains 405 by insulating
`dielectric layers 410. See id. at col. 10, ll. 49–50. The ’552 patent describes
`a process of making high quality contacts to the sources or drains, such as
`“self-aligned” contacts, by etching structures over substrate 400 and sources
`or drains 405. Id. at col. 7, ll. 19–22; col. 8, ll. 4–6.
`Figure 4(I) of the ’552 patent is reproduced below.
`
`
`Figure 4(I) illustrates additional structures deposited and etched over the
`structure described in Figure 4(D), such as second dielectric layer 440
`(called etch stop layer), blanket layer 450, and photoresist mask layer 455.
`Id. at col. 9, ll. 33–39; col. 11, ll. 63–65; col. 12, ll. 34–42. According to the
`’552 patent, etch stop layer 440, e.g., silicon nitride layer 440, depicted in
`Figure 4(I) is distinct or different from the underlying TEOS insulating
`layer. Id. at col. 12, ll. 10–11. The etch stop layer protects the underlying
`TEOS layer when blanket layer 450 made of BPTEOS1 is etched away to
`
`1 BPTEOS is an acronym for borophosphosilicate tetraethyl orthosilicate
`glass. See Ex. 1101, col. 11, ll. 6–7.
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`create contact openings 460 and 465 above source or drain 445. See id. at
`col. 12, ll. 36–42; col. 4, ll. 41–59.
`A second etch is then performed to remove etch stop layer 440
`covering source or drain 445 in contact openings 460 and 465. Id. at col. 12,
`ll. 48–52; col. 7, ll. 43–45. The ’552 patent describes that the second etch is
`“almost completely anisotropic,” which means that the etchant etches in the
`vertical direction, or perpendicular relative to the substrate surface. Id. at
`col. 7, ll. 45–48; col. 12, ll. 55–58. Hence, the etch removes the etch stop
`material covering the area of the contact openings or contact regions 460 and
`465, but does not significantly etch the etch stop material adjacent to the
`spacer portions 435. Id. at col. 7, ll. 53–55; col. 12, ll. 58–61. Figures 4(J)
`and 4(K) of the ’552 patent are reproduced below.
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`Figures 4(J) and 4(K) illustrate the structure of the semiconductor device of
`the ’552 patent after the second etch for removing the etch stop layer from
`the contact regions 460 and 465 is completed. As shown in Figures 4(J) and
`4(K), due to the anisotropic or vertical nature of the second etch, only a
`small portion, i.e., portion 475, of the TEOS spacer portion 435 is removed
`during the etch. Id. at col. 13, ll. 6–9. Of primary significance, according to
`the ’552 patent, the spacer portion 435 of the TEOS insulating layer 420
`retains its substantially rectangular profile, in contrast to the conventional
`prior art method which transforms a substantially rectangular spacer into a
`sloped spacer. Id. at col. 13, ll. 9–10; col. 7, ll. 48–51; col. 5, ll. 4–14.
`
`C. Illustrative Claim
`Claim 8 is illustrative of the challenged claims and is reproduced
`below with the key limitation (the “angle limitation”) emphasized in italics:
`1. A structure, comprising:
`(a) a first electrically conductive material formed in and/or on a
`surface of a substrate;
`(b) a contact opening in a region adjacent to a second
`electrically conductive material formed on the substrate;
`(c) an electrically insulative spacer in the contact opening
`adjacent to the second electrically conductive material;
`(d) an etch stop material over the electrically insulative spacer
`and the first and second electrically conductive materials, the
`etch stop material being a different material from the insulative
`spacer;
`(e) a blanket layer over the etch stop material; and
`(f) an opening through a first part of the etch stop material to
`the first electrically conductive material,
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`wherein a side of the electrically insulative spacer has an angle
`relative to the substrate surface that is either a right angle or
`an acute angle of more than 85°.
`
`D. Asserted Grounds of Unpatentability
`Petitioner asserts the following grounds of unpatentability (Pet. 9, 34–
`
`60):
`
`Claims Challenged
`
`Statutory Basis
`
`Ground
`
`8–12
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`8–12
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`§ 102(b)
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`§ 103(a)
`
`Anticipated by Heath2 (id. at 34–
`47, Ground 1)
`
`Obvious over Heath and Dennison3
`(id. at 47–60, Ground 2)
`
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`II. CLAIM CONSTRUCTION
`As acknowledged by the parties, the ’552 patent has expired. Pet. 28;
`Prelim. Resp. 14. Thus, we construe the claims in accordance with the
`standard set forth in Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005)
`(en banc). See In re Rambus, 694 F.3d 42, 46 (Fed. Cir. 2012) (“While
`claims are generally given their broadest possible scope during prosecution,
`the Board’s review of the claims of an expired patent is similar to that of a
`district court’s review.”). “In determining the meaning of the disputed claim
`limitation, we look principally to the intrinsic evidence of record, examining
`the claim language itself, the written description, and the prosecution
`history, if in evidence.” DePuy Spine, Inc. v. Medtronic Sofamor Danek,
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`2 Ex. 1103, U.S. Patent No. 4,686,000 (Aug. 11, 1987) (“Heath”).
`3 Ex. 1104, U.S. Patent No. 5,338,700 (Aug. 16, 1994) (“Dennison”).
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`Inc., 469 F.3d 1005, 1014 (Fed. Cir. 2006) (citing Phillips, 415 F.3d at
`1312–17). The words of a claim are generally given their ordinary and
`customary meaning, and that is the meaning the term would have to a person
`of ordinary skill at the time of the invention, in the context of the entire
`patent including the specification. See Phillips, 415 F.3d at 1312–1313. A
`particular embodiment appearing in the written description is generally not
`incorporated into a claim if the claim language is broader than the
`embodiment. SuperGuide Corp. v. DirecTV Enterprises, Inc., 358 F.3d 870,
`875 (Fed. Cir. 2004); see also Phillips, 415 F.3d at 1323 (“[A]lthough the
`specification often describes very specific embodiments of the invention, we
`have repeatedly warned against confining the claims to those
`embodiments.”). Only those terms which are in controversy need to be
`construed, and only to the extent necessary to resolve the controversy. Vivid
`Techs., Inc. v. Am. Sci. & Eng’g, Inc., 200 F.3d 795, 803 (Fed. Cir. 1999).
`
`“a side of the electrically insulative spacer has
`an angle relative to the substrate surface that is
`either a right angle or an acute angle of more than 85°”
`
`The parties’ claim construction dispute centers around the angle
`limitation set forth above, namely, the last limitation of claim 8 reciting that
`“a side of the electrically insulative spacer has an angle relative to the
`substrate surface that is either a right angle or an acute angle of more than
`85°.”4 Petitioner contends that this limitation should be construed to mean
`
`
`4 Claim 1 includes essentially the same limitation, the only difference being
`that claim 1 recites “insulating spacer” instead of “electrically insulative
`spacer” recited in claim 8. Tracking the language of the claims, the ’552
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`“a side of the insulating spacer has an angle relative to the horizontal
`substrate surface that is greater than 85° and less than or equal to 90°” (Pet.
`28), whereas Patent Owner asserts that the limitation should be interpreted to
`mean that “the insulating spacer [or the electrically insulative spacer] retains
`a substantially rectangular profile through the use of a low selectivity etch”
`(Prelim. Resp. 15–16, 19).
`Patent Owner’s claim construction argument is focused primarily on
`Patent Owner’s contention that the angle of a side of the insulating spacer
`must be obtained “through the use of a low selectivity etch.” Prelim. Resp.
`15–19. In support of its contention, Patent Owner cites various passages of
`the ’552 patent that describe the process of etching the etch stop layer using
`a low selectivity etch or purportedly distinguish the described invention
`from the prior art on the basis of the ’552 patent’s use of a low selectivity
`etch. Id. at 16–17 (citing Ex. 1101, col. 5, ll. 11–14; col. 7, ll. 58–60; col. 8,
`ll. 41–43; col. 13, ll. 55–62). Patent Owner’s argument is unpersuasive
`because the ’552 patent expressly states that the use of a low selectivity etch
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`patent uses the terms “insulating spacer” and “insulative spacer”
`interchangeably throughout the written description. See, e.g., Ex. 1101,
`col. 6, ll. 13–65; see also id. at col. 13, ll. 55–62 (using “the spacer portions
`of the insulating material” and “the spacer portions [of] insulative material”
`interchangeably). The parties also appear to use the terms “insulating
`spacer” and “insulative spacer” interchangeably in the Petition and the
`Preliminary Response. See, e.g., Pet. 28–29; Prelim. Resp. 15–16, 19. On
`this record, for purpose of this Decision, we deem the terms “insulating
`spacer” and “insulative spacer” to be interchangeable and to have no
`meaningful difference in their meaning.
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`described in the Specification is “exemplary” and does not limit the claimed
`invention. For example, the ’552 patent states as follows:
`The etchant utilized to remove silicon nitride from the
`contact opening 460 has a low selectivity for etching the silicon
`nitride material compared to the underlying TEOS layer 420.
`. . . The low selectivity etch yields a TEOS layer spacer portion
`435 that retains a rectangular or “boxy” profile. FIG. 4(K)
`illustrates that only a small portion 475 (illustrated in ghost
`lines) of the TEOS layer spacer portion 435 is removed during
`the etch. Of primary significance, the spacer portion 435 of the
`TEOS layer 420 retains its substantially rectangular profile.
`It is to be appreciated that the described etch stop layer
`etch conditions (i.e., low selectivity, low bombardment/high
`neutral flux) are exemplary of etch conditions that result in the
`retention of a boxy spacer.
`
`Ex. 1101, col. 12, l. 66–col. 13, l. 14 (emphases added). The ’552 patent
`further specifies that “[t]he invention relates to these process conditions as
`well as others that result in the retention of a boxy spacer,” and, therefore,
`“the etch-stop etch conditions should be regarded in an illustrative rather
`than restrictive sense.” Id. at col. 13, ll. 14–18 (emphases added).
`Furthermore, the challenged claims do not recite using a low
`selectivity etch, or, for that matter, any limitations relating to the conditions
`or methods of the etching process. In general, “even if all of the
`embodiments discussed in the patent included a specific limitation, it would
`not be proper to import from the patent’s written description limitations that
`are not found in the claims themselves.” Cadence Pharm. Inc. v. Exela
`PharmSci Inc., 780 F.3d 1364, 1369 (Fed. Cir. 2015) (emphasis added)
`(citations omitted) (internal quotation marks omitted). Further, “it is
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`improper to read limitations from a preferred embodiment described in the
`specification—even if it is the only embodiment—into the claims absent a
`clear indication in the intrinsic record that the patentee intended the claims
`to be so limited.” Epos Techs. Ltd. v. Pegasus Techs. Ltd., 766 F.3d 1338,
`1341 (Fed. Cir. 2014). In view of the passages of the ’552 patent quoted
`above that describe the use of a low selectivity etch as “exemplary” or
`“illustrative” and not restrictive, we find the disclosure of the ’552 patent
`cited by Patent Owner as purportedly limiting the invention does not rise to
`the level of a clear indication that the patentee intended to limit the
`challenged claims to require the use of a low selectivity etch.
`Patent Owner further contends that the claims are limited because,
`during the prosecution of the ’552 patent, the patentee contrasted the
`invention from the use of highly selective etches in the prior art. Prelim.
`Resp. 17–19 (citing Ex. 1118, 4). According to Patent Owner, the patent
`applicant stated in an amendment and response to an Office Action as
`follows:
`
`In the past, the practice with respect to forming contact
`openings during the fabrication of semiconductor devices,
`particularly self-aligned contact openings, was to use etchants
`with high selectivity to protect underlying regions. However,
`the properties of a highly selective etch of the overlying etch
`layer can transform a substantially rectangular spacer adjacent
`to the contact region into a sloped spacer. . . .
`The present invention avoids this problem by retaining
`the substantially rectangular profile of the insulating spacers.
`As illustrated in Figure 4K of the present specification, the
`spacer retains a substantially rectangular or “boxy” profile,
`i.e.[,] the sides of the spacer are not sloping.
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`Id. (quoting Ex. 1118, 4). Prosecution history disclaimers, like specification
`disclaimers discussed above, must be clear and unambiguous: “[W]hile the
`prosecution history can inform whether the inventor limited the claim scope
`in the course of prosecution, it often produces ambiguities created by
`ongoing negotiations between the inventor and the PTO. Therefore, the
`doctrine of prosecution disclaimer only applies to unambiguous disavowals.”
`Shire Dev., LLC v. Watson Pharm., Inc., 787 F.3d 1359, 1365 (Fed. Cir.
`2015) (citations omitted). The patentee’s prosecution history statements
`quoted above convey that the ’552 patent avoids the problem of the prior art
`by “retaining the substantially rectangular profile of the insulating spacers”
`but do not unambiguously specify that such rectangular profile is obtained
`only by using a low selectivity etch. See Ex. 1118, 4. Therefore, in view of
`the express statements in the ’552 patent that describe the use of a low
`selectivity etch in obtaining rectangular insulating spacers as “exemplary” or
`“illustrative” and not restrictive, the cited prosecution history statements do
`not rise to the level of unambiguous disavowal or disclaimer that limits the
`challenged claims to require the use of a low selectivity etch.
`Based on the foregoing, we preliminarily conclude, for purposes of
`this Decision, that the challenged claims do not require the use of a low
`selectivity etch.
`Petitioner’s proposed construction of the angle limitation largely
`tracks the claim language except that Petitioner proposes to expressly
`construe two terms or phrases as follows: (1) the term “an angle relative to
`the substrate surface” should be construed to mean “an angle relative to the
`horizontal substrate surface,” and (2) the phrase “an angle . . . that is either a
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`right angle or an acute angle of more than 85°” should be interpreted to
`mean “an angle . . . that is greater than 85° and less than or equal to 90°.”
`We agree with and accept the second part of Petitioner’s proposed
`construction as it essentially incorporates the well-established mathematical
`definitions of the recited terms “a right angle” and “an acute angle” 5 in
`plane geometry. In support of the first part of its proposed construction,
`Petitioner cites various portions of the ’552 patent that purportedly describe
`that the substrate surface is horizontal or that the angle of an insulating
`spacer is measured relative to a horizontal surface of the substrate. Pet. 29–
`31 (citing Ex. 1101, col. 5, ll. 13–17; col. 7, ll. 45–48; Figs. 2(B), 4(K)). For
`purposes of this Decision, we do not find it necessary to construe
`specifically the phrase “an angle relative to the substrate surface” because
`our decision does not rest on express construction of the term.
`In addition, although Petitioner does not propose an express
`construction for “a side” of an insulating spacer, Petitioner contends that the
`term “a side” should be accorded its plain meaning—i.e., any side—and,
`therefore, should not be limited to any particular side or any particular
`portion of a side of the insulating spacer. Id. at 28–31. In supports of its
`position, Petitioner cites passages in the written description of the ’552
`patent that describe the angle of a side of the insulating spacer as being
`measured at the bottom right side portion as well as at the top right side
`portion of the insulating spacer. Id. at 30–31 (citing Ex. 1101, col. 5, ll. 13–
`17; col. 8, ll. 41–43; col. 13, ll. 9–10; Figs. 2(B), 4(K)). Patent Owner does
`
`5 See, e.g., Types of Angle, MATH OPEN REFERENCE,
`http://www.mathopenref.com/angleacute.html (Ex. 3101).
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`not present any rebuttal argument specifically addressing Petitioner’s
`contentions regarding the non-limiting interpretation of “a side.” On this
`record, we agree with Petitioner that interpreting the term “a side” according
`to its plain meaning as any side is consistent with the disclosure in the
`written description of the ’552 patent and that the term is not limited to any
`particular side or any particular portion of a side of the insulating spacer.
`As indicated in the Claim Construction Order (Ex. 1124) entered by
`the District Court, the parties agreed in the related district court litigation to
`use the Petitioner’s proposed construction of the angle limitation of claim 1
`with the word “horizontal” removed—that is, “a side of the insulating spacer
`has an angle relative to the substrate surface that is greater than 85° and less
`than or equal to 90°.” Ex. 1124, 7–8. This agreed construction, which was
`adopted by the District Court (id. at 8), is consistent with our claim
`construction analysis of the angle limitation of claim 8 discussed above.
`Accordingly, for purposes of this Decision, consistent with the parties’
`agreed construction at the district court, we preliminarily construe the angle
`limitation to mean “a side of the electrically insulative spacer has an angle
`relative to the substrate surface that is greater than 85° and less than or equal
`to 90°.”
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`III. ANALYSIS OF PETITIONER’S PRIOR ART CHALLENGES
`
`A. Anticipation By Heath
`Petitioner contends claims 8–12 are unpatentable under 35 U.S.C.
`§ 102(b) as anticipated by Heath. Pet. 34–47. Petitioner provides detailed
`explanations and specific citations to Heath indicating where in the reference
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`the claimed features are disclosed. Id. In addition, Petitioner relies upon the
`Declaration of John C. Bravman, Ph.D. (“Bravman Decl.,” Ex. 1102) to
`support its position. Id.
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`1. Principles of Law
`A claim is unpatentable under 35 U.S.C. § 102 only if a single prior
`art reference expressly or inherently describes each and every limitation set
`forth in the claim. See Perricone v. Medicis Pharm. Corp., 432 F.3d 1368,
`1375 (Fed. Cir. 2005); Verdegaal Bros., Inc. v. Union Oil Co., 814 F.2d 628,
`631 (Fed. Cir. 1987). Further, a reference cannot anticipate “unless [it]
`discloses within the four corners of the document not only all of the
`limitations claimed[,] but also all of the limitations arranged or combined in
`the same way as recited in the claim.” Net MoneyIN, Inc. v. VeriSign, Inc.,
`545 F.3d 1359, 1371 (Fed. Cir. 2008). Although the elements must be
`arranged in the same way as in the claim, “the reference need not satisfy an
`ipsissimis verbis test,” i.e., identity of terminology is not required. In re
`Gleave, 560 F.3d 1331, 1334 (Fed. Cir. 2009); In re Bond, 910 F.2d 831,
`832 (Fed. Cir. 1990). We analyze this asserted ground based on anticipation
`with the principles identified above in mind.
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`2. Overview of Heath
`Heath describes a process for forming a self-aligned contact window
`in a semiconductor device, such as an integrated circuit. Ex. 1103, Abstract.
`Heath describes a two-step etching process which comprises the steps of first
`etching a dielectric layer down to a silicon nitride etch stop layer, and then
`etching the etch stop, leaving a “stick” of the etch stop material on the
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`vertical sidewall of the layer to be protected. Id. Figure 8B of Heath is
`reproduced below.
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`Figure 8B depicts a cross-sectional view of a semiconductor structure after
`the first etching step, including gate electrode 16 insulated from contact
`window 32 and source or drain 20 by silicon nitride layer 10. See id. at
`col. 9, ll. 50–67. In the second etching step, etch stop layer 10 is removed to
`open contact window 32 to source or drain 20. Heath describes that, because
`the nitride removal is anisotropic, vertical “stick” 10a of nitride layer 10 will
`remain on the side of gate electrode 16 so that no electrical short occurs
`between the gate electrode and the contact window or the source or drain
`region. Id. at col. 10, ll. 1–11.
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`Claim 8
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`3. Analysis
`
`Petitioner contends that the embodiment depicted in Figure 8C of
`Heath discloses every limitation of claim 8. Pet. 34. Figure 8C of Heath is
`reproduced below.
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`Figure 8C above depicts a cross-sectional view of a semiconductor structure
`at the same stage of processing as Figure 8B combined with the addition of a
`sidewall spacer 16a. Ex. 1103, col. 10, ll. 14–19. Referencing Figure 8C,
`Petitioner provides detailed explanations and specific citations to Heath
`indicating where in the reference each limitation of claim 8 is disclosed. Pet.
`34–43. For example, Petitioner asserts that source/drain 20 depicted in
`Figure 8C discloses “a first electrically conductive material formed in and/or
`on a surface of a substrate” recited in claim 8. Id. at 34–36 (citing Ex. 1103,
`col. 8, ll. 2–5; col. 9, ll. 50–55; Figs. 2–7, 8C), 35 n.7 (citing Ex. 1103,
`col. 7, ll. 36–41, 56–58; Figs. 2–7). Petitioner also contends that gate
`electrode 16 depicted in Figure 8C discloses “a second electrically
`conductive material formed on the substrate,” as recited in claim 8. Id. at
`36–37 (citing Ex. 1103, col. 7, ll. 36–38; col. 8, ll. 8–11; col. 9, ll. 44–47,
`50–52; Figs. 2, 8C). Petitioner further asserts that contact window 32 shown
`in Figure 8C discloses “a contact opening in a region adjacent to a second
`electrically conductive material formed on the substrate” recited in claim 8
`because contact window 32 is formed in a region adjacent to the gate
`electrode 16. Id. at 37–38 (citing Ex. 1103, col. 10, ll. 58–59; Fig. 8C).
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`Petitioner contends, therefore, Heath discloses elements (a) and (b) of claim
`8. Id. at 34–38.
`Petitioner provides an annotated version of Figure 8C of Heath as
`shown below.
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`Annotated version of Figure 8C in Petition
`Id. at 38. Referencing the annotated Figure 8C shown above, Petitioner
`contends that sidewall spacer 16a depicted in Figure 8C discloses an
`“electrically insulative spacer” recited in claim 8. Id. at 38–39 (citing
`Ex. 1103, col. 10, ll. 12–27; Fig. 8C). Citing the testimony of Dr. Bravman,
`Petitioner argues that sidewall spacer 16a is an insulative oxide. Id. at 39
`(citing Ex. 1102 (Bravman Decl.) ¶ 82; Ex. 1103, col. 10, ll. 23–25 (“spacer
`16a formed illustratively of oxide”)). Petitioner further argues Figure 8C
`shows that sidewall spacer 16a is in the contact region, i.e., contact window
`32, which is adjacent to the electrically conductive gate electrode 16. Id. at
`38–39. Petitioner contends, therefore, Heath discloses element (c) of claim
`8, i.e., “an electrically insulative spacer in the contact opening adjacent to
`the second electrically conductive material.” Id. Petitioner provides a
`further annotated version of Figure 8C, which is reproduced below.
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`Id. at 39. Annotated Figure 8C above shows Petitioner’s identification of
`element (d) of claim 8 present in Heath. Referencing the annotated Figure
`8C shown above, Petitioner contends that Figure 8C shows a silicon nitride
`etch stop layer 10 over electrically insulative sidewall spacer 16a and
`electrically conductive diffusion region 20 and gate electrode 16, and,
`therefore, Heath discloses “an etch stop material over the electrically
`insulative spacer and the first and second electrically conductive materials”
`recited in element (d) of claim 8. Id. Petitioner further argues that Heath
`discloses that etch stop layer 10 is a different material—specifically, silicon
`nitride—from the sidewall spacer 16a, which is formed of oxide. Id. at 39–
`40 (citing Ex. 1102 ¶ 84; Ex. 1103, Abstract; col. 5, ll. 38–39; col. 9, ll. 2–4,
`66–67; col. 10, ll. 12–27). Petitioner contends that Heath, therefore,
`discloses element (d) of claim 8, which recites “an etch stop material over
`the electrically insulative spacer and the first and second electrically
`conductive materials, the etch stop material being a different material from
`the insulative spacer.” Id.
`Petitioner further contends that, in both the ’552 patent and Heath, a
`vertical “stick” of etch stop material (i.e., the vertical stick 10a in Heath and
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`the etch stop material 440 adjacent to the spacer portion 435 in the ’552
`patent) remains adjacent to the sidewall spacer in the contact opening after
`the etching process forms the contact opening. Id. at 40 (citing Ex. 1101,
`col. 12, ll. 58–65; Ex. 1103, col. 10, ll. 1–11; Ex. 1102 ¶ 85).
`In addition, Petitioner contends that Heath discloses element (e) of
`claim 8, which recites “a blanket layer over the etch stop material,” because
`Heath discloses dielectric layer 34 over the etch stop layer 10. Id. at 41
`(citing Ex. 1102 ¶ 86; Ex. 1103, col. 7, ll. 48–50 (“A very thick BPSG
`(borophosphosilicate glass) dielectric 34 covers the layer 10 except in
`contact windows 30 and 32.”), Fig. 8C).
`Petitioner contends that Heath also discloses the angle limitation
`recited in claim 8. According to Petitioner, Heath discloses a sidewall
`spacer 16a with a side that is at a right angle relative to the substrate surface
`because Heath describes the sidewall spacers as “vertical” with respect to the
`substrate. Id. at 41–42 (citing Ex. 1102 ¶ 88; Ex. 1103, Abstract; col. 11,
`ll. 1–10; Fig. 8C). Pointing to Figure 8C of Heath, Petitioner argues Heath
`describes that the entire side of the sidewall spacer is at a 90° angle relative
`to the substrate surface, and, therefore, the sidewall spacer meets the angle
`limitation regardless of where along the side of the sidewall spacer—be it
`near the bottom or near the top of the spacer—the angle is measured relative
`to the substrate surface. Id. at 42–43.
`Patent Owner contends that Heath does not disclose the angle
`limitation recited in claim 8 because Heath does not describe using a low
`selectivity etch to obtain substantially rectangular insulative spacers. Prelim.
`Resp. 26–30. Patent Owner further asserts that Heath is merely cumulative
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`of the prior art structure disclosed in the Background of the Invention
`section of the ’552 patent and that the vertical sidewall that is allegedly
`shown in Figure 8C of Heath is the same as the prior art “vertical sidewall”
`that is shown in Figure 1(B) of the ’552 patent. Id. at 26–29. Patent Owner
`contends that both figures do not show actual etching effects and that
`Heath’s use of a selective etch process will result in a final structure with a
`sloped spacer, not a spacer with a substantially rectangular profile required
`by claim 8. Id. at 27–29. According to Patent Owner, the ’552 patent
`improves upon the vertical sidewall spacers present in the background prior
`art discussed in the ’552 patent in that the claimed invention uses a low
`selectivity etch instead of a selective etch process. See id. at 29–30.
`Patent Owner’s argument primarily turns on the claim construction of
`the angle limitation and is, therefore, unpersuasive for the reasons discussed
`above in the context of our claim construction analysis. Furthermore, we are
`not persuaded vertical sidewall spacers are present in Figure 1(B) of the ’552
`patent because, other than pointing to Figure 1(B), Patent Owner provides no
`further explanation or supporting evidence to show why the dielectric spacer
`150 depicted in Figure 1(B) has a vertical sidewall relative to the substrate
`surface. Nor do we discern any disclosure in the ’552 patent that describes
`an insulating spacer depicted in Figure 1(B) as having a vertical sidewall.
`Rather, the ʼ552 patent describes in detail that the prior art process of
`forming contact regions tra
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