Court Opinion

ID: 4189181
Source: CourtListenerOpinion
Date Created: 2017-07-25 15:02:08.127331+00
Date Added: 2024-06-11T14:13:54.571787
License: Public Domain

NOTE: This disposition is nonprecedential.

  United States Court of Appeals
      for the Federal Circuit
                ______________________

    HOME SEMICONDUCTOR CORPORATION,
                Appellant

                           v.

 SAMSUNG ELECTRONICS CO., LTD., SAMSUNG
   ELECTRONICS AMERICA, INC., SAMSUNG
  SEMICONDUCTOR, INC., SAMSUNG AUSTIN
          SEMICONDUCTOR LLC,
                  Appellees
           ______________________

                      2016-2215
                ______________________

    Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. IPR2015-
00460.
                 ______________________

                Decided: July 25, 2017
                ______________________

    CRAIG R. KAUFMAN, TechKnowledge Law Group LLP,
Redwood City, CA, argued for appellant. Also represent-
ed by JERRY CHEN.

    MICHAEL J. MCKEON, Fish & Richardson, PC, Wash-
ington, DC, argued for appellees. Also represented by
CRAIG E. COUNTRYMAN, San Diego, CA.
2          HOME SEMICONDUCTOR CORP.     v. SAMSUNG ELECS. CO.

                  ______________________

    Before LOURIE, MOORE, and O’MALLEY, Circuit Judges.
LOURIE, Circuit Judge.
    Home Semiconductor Corp. (“Home”) appeals from the
final written decision of the United States Patent and
Trademark Office Patent Trial and Appeal Board (“the
Board”) in an inter partes review (“IPR”) proceeding
finding that, inter alia, claims 2 and 9–14 of U.S. Patent
6,146,997 (“the ’997 patent”) are unpatentable as antici-
pated by U.S. Patent 6,277,720 (“Doshi”). Home Semi-
conductor Corp. v. Samsung Elecs. Co., No. IPR2015-
00460, 2016 Pat. App. LEXIS 7424 (P.T.A.B. Apr. 20,
2016) (“Final Decision”). For the reasons that follow, we
reverse.
                        BACKGROUND
     This appeal primarily involves the meaning of the
word “over” in the context of the claims, written descrip-
tion, and figures. Home owns the ’997 patent, which is
directed to “a simplified method for forming a self-aligned
contact hole,” in which a conductive plug can be formed to
electrically connect the semiconductor device to other
circuit elements. ’997 patent col. 2 ll. 3–4, col. 3 ll. 25–31.
The ’997 patent first describes the conventional technique
of forming a self-aligned contact hole, which involves the
separate steps of (1) forming “nitride spacers 22a” by
depositing and anisotropically etching “a conformal lay-
er of silicon nitride 22”; and (2) forming the “contact hole
29” after depositing another “conformal layer of etch
barrier material 24,” which “serv[es] as an etch stop” and
is later partially removed to “expose the diffusion region
18.” Id. col. 1 ll. 33–57, figs. 1B–E. The ’997 patent then
describes a simplified process that “reduces one etch step
and one deposition step as compared to the conventional
method.” Id. col. 3 ll. 10–42. Instead of two separate
steps of forming the nitride spacers and forming the
HOME SEMICONDUCTOR CORP.     v. SAMSUNG ELECS. CO.           3

contact hole, each performed after a deposition of respec-
tive conformal layers 22, 24, the ’997 patent describes a
process involving one “conformal layer of silicon nitride
62,” which is anisotropically etched to “[s]imultaneously”
form “nitride spacers 62a” and a “contact hole 67.” Id. col.
2 l. 60–col. 3 l. 25.
    In both of the known and simplified processes de-
scribed in the ’997 patent, “a thin oxide layer” 20, 60 is
“formed over the substrate surface and on the sidewalls of
the gate electrode” before the conformal layer 22, 62 is
deposited, id. col. 1 ll. 29–31, col. 2 ll. 55–57 (emphasis
added); id. figs. 1A, 2A, and once the thin oxide layer 60 is
formed and the conformal layer 62 is deposited, the semi-
conductor structure at this intermediate stage of the
described process appears as below:

id. fig. 2B; see also id. fig. 1B. Later, a portion of the thin
oxide layer is removed “to expose the diffusion region.”
Id. col. 1 ll. 38–40, col. 3 ll. 22–24.
    Claim 2 of the ’997 patent reads as follows:
    2. The method as claimed in claim 1, further com-
    prising a step of forming an oxide layer over the
    diffusion region and on the sidewalls of the gate
    electrode by thermal oxidation prior to forming
    the barrier layer.
Id. col. 4 ll. 5–8 (emphasis added). Claim 9 is an inde-
pendent claim involving multiple steps and includes a
4         HOME SEMICONDUCTOR CORP.     v. SAMSUNG ELECS. CO.

similar step of “forming an oxide layer over the diffusion
region and on the sidewalls of the gate electrode by ther-
mal oxidation.” Id. col. 4 ll. 32–34 (emphasis added).
Claims 10–14 depend from claim 9 and add additional
limitations not at issue on appeal.
     Samsung Electronics Co., Ltd., Samsung Electronics
America, Inc., Samsung Semiconductor, Inc., and Sam-
sung Austin Semiconductor LLC (together, “Samsung”)
filed a petition for IPR of the ’997 patent, alleging that
claims 1–14 were anticipated by Doshi, that claims 1 and
3–8 were anticipated by U.S. Patent 5,770,498 (“Becker”),
and that claims 2 and 9–14 would have been obvious over
Becker and Wong, et al., Process Induced Degradation of
Thin Oxides, ULSI SCI. & TECH. (1987). The Board insti-
tuted review only on the anticipation ground based on
Doshi. Home Semiconductor Corp. v. Samsung Elecs. Co.,
No. IPR2015-00460, 2015 WL 3430191, at *8 (P.T.A.B.
May 27, 2015).
    In its patent owner response, Home argued that
“forming an oxide layer over the diffusion region” in
claims 2 and 9 should mean “forming an oxide layer
covering the diffusion region” in light of the specification.
J.A. 499 (emphasis added). Based on its proposed con-
struction, Home argued that Doshi did not anticipate the
challenged claims.
    In reply, as it had done in its IPR petition, Samsung
argued that the broadest reasonable interpretation of
“forming an oxide layer over the diffusion region” should
be “forming an oxide layer above the diffusion region.”
J.A. 695–96 (emphasis added). Samsung argued that
construing “over” as “covering” was too narrow a reading
for a person of ordinary skill in the art and that its argu-
ment was supported by Becker, which describes gate
electrode structures that do not cover the substrate as
being “over” the substrate.
HOME SEMICONDUCTOR CORP.     v. SAMSUNG ELECS. CO.           5

    In its final written decision, the Board construed, in-
ter alia, “forming an oxide layer over the diffusion region”
in claims 2 and 9 as “forming an oxide layer above the
diffusion region,” as proposed by Samsung. Final Deci-
sion, 2016 Pat. App. LEXIS 7424, at *15. In rejecting
Home’s proposed claim construction, the Board reasoned
that Home essentially argued for “over” to be construed as
“completely covering” and that the plain meaning of
“over” and the specification, which does not use the word
“covering,” are consistent with understanding “over” to
mean “above.” Id. at *12–14. According to its claim
construction, the Board found that all the challenged
claims were anticipated by Doshi.
     Doshi, entitled “Silicon Nitride Dopant Diffusion Bar-
rier in Integrated Circuits,” is generally directed to “a
silicon nitride diffusion barrier layer underlying a planar-
izing doped oxide layer” so that “dopant in planarizing
insulating films is prevented from diffusing into the active
regions of the integrated circuit.” Doshi col. 4 ll. 12–14,
21–23. In particular, Doshi describes that “sidewall
filaments 11 are formed by first oxidizing the sides of
polysilicon layer 22” and that “[a] layer of silicon nitride is
then deposited overall, and then etched anisotropically to
remove the nitride from flat surfaces, leaving sidewall
filaments 11 behind.” Doshi col. 7 ll. 58–62. Subsequent-
ly, a silicon nitride layer 30 is formed; the resulting
semiconductor structure at this intermediate stage is
shown below:
6          HOME SEMICONDUCTOR CORP.       v. SAMSUNG ELECS. CO.

Doshi fig. 3a (in part); see also id. fig. 3b (in part).
     In finding that Doshi anticipated “forming an oxide
layer over the diffusion region,” the Board found that
“Doshi discloses forming an oxide layer on the sidewalls of
the gate electrode.” Final Decision, 2016 Pat. App. LEXIS
7424, at *35–36. The Board found that “Doshi describes
that the sidewall filaments 11 are formed by first oxidiz-
ing the sides of the polysilicon layer 22” and that “the
oxide layer (filaments 11) is above the diffusion region,”
“which includes source/drain extensions 7’.” Id. at *32–
33. The Board disagreed with Home, who argued that the
oxide layer in Doshi is “higher but off to the side,” and
found that “Doshi discloses [that] the oxide layer (sidewall
filaments 11) is above the diffusion region, and not merely
‘off to the side’ as argued by [Home].” Id. at *33–36.
    Home timely appealed. We have jurisdiction pursu-
ant to 28 U.S.C. § 1295(a)(4)(A).
                          DISCUSSION
     In IPR proceedings, the Board gives claim terms their
broadest reasonable interpretation in light of the claim
language and the specification. See Cuozzo Speed Techs.,
LLC v. Lee, 136 S. Ct. 2131, 2142–46 (2016). We review
the Board’s ultimate claim constructions de novo and
underlying factual determinations involving extrinsic
evidence for substantial evidence. Microsoft Corp. v.
Proxyconn, Inc., 789 F.3d 1292, 1297 (Fed. Cir. 2015)
(citing Teva Pharm. U.S.A., Inc. v. Sandoz, Inc., 135 S. Ct.
831, 841–42 (2015)).
    A patent claim is anticipated “only if each and every
element is found within a single prior art reference,
arranged as claimed.” Summit 6, LLC v. Samsung Elecs.
Co., 802 F.3d 1283, 1294 (Fed. Cir. 2015) (citing Net
MoneyIN, Inc. v. VeriSign, Inc., 545 F.3d 1359, 1369 (Fed.
Cir. 2008)). Anticipation is a question of fact that we
HOME SEMICONDUCTOR CORP.   v. SAMSUNG ELECS. CO.         7

review for substantial evidence. REG Synthetic Fuels,
LLC v. Neste Oil Oyj, 841 F.3d 954, 958 (Fed. Cir. 2016).
Substantial evidence is “such relevant evidence as a
reasonable mind might accept as adequate to support a
conclusion.” In re Gartside, 203 F.3d 1305, 1312 (Fed.
Cir. 2000) (quoting Consol. Edison Co. v. NLRB, 305 U.S.
197, 229 (1938)). Thus, we reverse the Board’s anticipa-
tion findings when substantial evidence does not support
the Board’s decision. See, e.g., Nidec Motor Corp. v.
Zhongshan Broad Ocean Motor Co., 851 F.3d 1270, 1275
(Fed. Cir. 2017); In re Man Machine Interface Techs. LLC,
822 F.3d 1282, 1287 (Fed. Cir. 2016); In re Skvorecz, 580
F.3d 1262, 1267–68 (Fed. Cir. 2009).
     On appeal, Home challenges the Board’s construction
of “forming an oxide layer over the diffusion region” and
its findings that claims 2 and 9–14 are anticipated by
Doshi. We address each issue in turn.
   I. Construction of “Forming an Oxide Layer over the
                     Diffusion Region”
     Home argues that the Board’s construction of “over”
as “above” is unreasonably broad and inconsistent with
the specification, citing figures and various uses of the
term “over” in the specification. Appellant’s Br. 16–19.
Home maintains that “over” should be construed as
“covering,” id. at 16, and argues that its proposed con-
struction of “over” means only “covering,” not “completely
covering,” and it faults Samsung for “recast[ing]” its
construction, Appellant’s Reply 1–2. Yet, Home contends
that “‘covering’ means ‘covering’ the entire relevant
region.” Appellant’s Br. 19. During oral argument, Home
was repeatedly asked to clarify its claim construction
position, and Home presented its claim construction as
“effectively cover[ing] the entire surface” but admitted
that it had not argued in its briefings for any alternative
construction other than “covering,” such as “substantially
covering.” Oral Argument at 3:20–24, 5:00–09, 7:36–50,
8         HOME SEMICONDUCTOR CORP.     v. SAMSUNG ELECS. CO.

30:48–31:30, Home Semiconductor Corp. v. Samsung
Elecs. Co., No. 16-2215 (Fed. Cir. June 9, 2017),
http://oralarguments.cafc.uscourts.gov/default.aspx?fl=20
16-2215.mp3.
    Samsung contends that the Board correctly construed
the term “over” as “above,” giving the term “the full
breadth of its ordinary meaning.” Appellee’s Br. 14–15.
Samsung argues that construing “over” as “covering” is
not supported by the use of the term “over” in the specifi-
cation and would result in improperly importing limita-
tions into the claims. Samsung also maintains that the
specification and another prior art reference, Becker,
support that “over” cannot mean completely covering.
    We conclude that the Board’s construction of “over” as
meaning “above” is unreasonable in light of the claim
language and the specification.
    The Board construed “forming an oxide layer over the
diffusion region” to mean “forming an oxide layer above
the diffusion region,” adopting the broad construction of
the term “over” that Samsung proposed. The Board
discussed how its construction of “over” as “above” is
consistent with the specification; however, it adopted its
construction without regard to the context in which it is
used in the claims and the specification. In adopting the
“full breadth” of the term as advocated by Samsung, the
Board focused on the word “above,” rather than the claim
term “over.” That was error.
    Even when giving the claim term the broadest rea-
sonable interpretation, the Board cannot construe the
claims “so broadly that its constructions are unreasonable
under general claim construction principles.” Microsoft,
789 F.3d at 1298 (emphasis in original). “[T]he protocol of
giving claims their broadest reasonable interpreta-
tion . . . does not include giving claims a legally incorrect
interpretation” “divorced from the specification and the
HOME SEMICONDUCTOR CORP.    v. SAMSUNG ELECS. CO.          9

record evidence.”   Id. (citations and internal quotation
marks omitted).
    As in any claim construction, we start with the claim
language itself. See PPC Broadband, Inc. v. Corning
Optical Commc’ns RF, LLC, 815 F.3d 747, 752 (Fed. Cir.
2016). The language at issue is not simply “over,” but is
“forming an oxide layer over the diffusion region,” and the
use of the term “over” in “forming an oxide layer over the
diffusion region” connotes more than an insignificant or
incidental vertical overlap between the oxide layer and
the diffusion region. Although “over” and “above” can be
interchangeable in certain contexts, they are not coexten-
sive here, and the full scope of “above,” which is not a
claim term, cannot be adopted to give meaning to the
actual claim term “over” if that adoption would result in
an unreasonable interpretation of the claim term in
context. This understanding of the claim term “over” is
also supported by the specification, which repeatedly
describes two significantly overlapping layers or struc-
tures as one being “over” another. ’997 patent col. 1 ll.
29–31, 41–47, col. 2 ll. 55–58, 60–62, col. 3 ll. 1–3, 17–20.
    The Board, in its claim construction, brought into the
claim the concept of the oxide layer being merely higher
in position relative to the diffusion region regardless of
the minor extent of the vertical overlap between the oxide
layer and the diffusion region, which is contrary to the
claim language itself and to the specification. In so doing,
the Board injected ambiguity into its claim construction
by replacing the claim term “over” with “above” and then
resolved that ambiguity by erring on the side of a broader
understanding of the word “above” to reach its anticipa-
tion finding.
    The Board’s reading of “forming an oxide layer over
the diffusion region” is also inconsistent with the remain-
ing language of claims 2 and 9. The common limitations
of claims 2 and 9 read: “forming an oxide layer over the
10        HOME SEMICONDUCTOR CORP.     v. SAMSUNG ELECS. CO.

diffusion region and on the sidewalls of the gate electrode
by thermal oxidation.” ’997 patent col. 4 ll. 6–8, 32–34
(emphasis added). Generally, claim construction that
gives “meaning to all of a claim’s terms,” Apple, Inc. v.
Ameranth, Inc., 842 F.3d 1229, 1237 (Fed. Cir. 2016), and
does not “render[] other parts of the claim superfluous,”
Merck & Co., Inc. v. Teva Pharm. USA, Inc, 395 F.3d
1364, 1372 (Fed. Cir. 2005), is favored. See Wasica Fin.
GmbH v. Cont’l Auto. Sys., Inc., 853 F.3d 1272, 1288 n.10
(Fed. Cir. 2017).
    The ’997 patent describes that “a thin oxide layer 60
having a thickness of about 150 Å is formed over the
substrate surface and on the sidewalls of the gate elec-
trode 54 by rapid thermal oxidation at about 800 to 1100
°C,” col. 2 ll. 55–59, and shows the semiconductor struc-
ture at this stage as below:

id. fig. 2A. The full claim limitation read in light of the
specification indicates that the oxide is formed both “over
the diffusion region,” that is, “over the substrate surface,”
and “on the sidewalls of the gate electrode,” which is
separate from the oxide formed “over the diffusion re-
gion.” If “forming an oxide layer over the diffusion region”
is so broadly interpreted that forming an oxide on the
sidewalls of the gate electrode that is merely higher than
the diffusion region can correspond to “forming an oxide
layer over the diffusion region,” then the remainder of the
claim limitation, namely “and on the sidewalls of the gate
electrode,” would be rendered superfluous.
HOME SEMICONDUCTOR CORP.    v. SAMSUNG ELECS. CO.        11

    We therefore conclude that the Board erred in con-
struing “over” to mean “above.”
    However, we decline to adopt Home’s proposed con-
struction of “over” to mean an unqualified “covering.” In
support of its proposed claim construction, Home in part
refers to Figure 2D, which is reproduced below, and shows
the semiconductor structure after “the conformal nitride
layer 62 underneath the opening is anisotropically etched
to remove the portion over the diffusion region 58.” ’997
patent, col. 3 ll. 17–20 (emphasis added).

Id. fig. 2D. Home argues that “the portion over the diffu-
sion region 58” that is being removed according to this
description is the portion that “covers” the diffusion
region 58 and suggests that the term “over” should be
construed as “covering” accordingly. Appellant’s Br. 17–
18. However, as Home acknowledged during oral argu-
ment, this construction of “over” as “covering” requires a
previously unarticulated qualifier, such as “effectively” or
“substantially,” which Home has not argued and hence we
do not consider.
     Thus, even though we conclude that the Board erred
in its claim construction of “over” as “above,” we find that
neither Home’s inconsistent proposed constructions of
“over,” nor Samsung’s, which the Board adopted, is per-
12         HOME SEMICONDUCTOR CORP.      v. SAMSUNG ELECS. CO.

suasive. In light of the full claim limitation and the
specification, we conclude that regardless of the argu-
ments of the parties and the reasoning of the Board,
“forming an oxide layer over the diffusion region” should
be understood in the context of “forming an oxide layer
over the diffusion region and on the sidewalls of the gate
electrode by thermal oxidation,” which means forming an
oxide layer over the diffusion region in addition to on the
sidewalls of the gate electrode.
    Accordingly, we conclude that the claims in which
“forming an oxide layer over the diffusion region” appear
are not anticipated by Doshi, for reasons stated below.
                  II. Anticipation by Doshi
     In discussing Doshi’s teachings, the Board determined
that “sidewall filaments 11 are formed by first oxidizing
the sides of polysilicon layer 22,” and appears to have
proceeded on the assumption that the sidewall filaments
11 are oxide layers. Final Decision, 2016 Pat. App. LEXIS
7424, at *32–36. To the extent that the Board equated
the sidewall filament 11 to an oxide layer, that was an
error that is not supported by Doshi’s own teachings. In
Doshi, oxidizing the sides of the polysilicon layer 22 is
only the “first” step of forming the sidewall filaments 11.
Doshi col. 7 ll. 58–59. The remaining steps of forming the
sidewall filaments 11 entail “deposit[ing]” “[a] layer of
silicon nitride . . . overall” and “anisotropically” “etch[ing]”
that layer of silicon nitride “to remove the nitride from
flat surfaces,” which “leav[es] sidewall filaments 11
behind,” i.e., completes the “formation of the sidewall
filaments 11.” Doshi col. 7 ll. 59–62, 66.
    Perhaps recognizing this shortcoming of the Board’s
analysis, Samsung urges that by siding with Samsung,
the Board actually adopted its contention that the side-
wall filament 11 “includes an oxide layer.” Appellee’s Br.
22 (emphasis added). On appeal, Samsung further refines
its previous arguments that were before the Board and
HOME SEMICONDUCTOR CORP.    v. SAMSUNG ELECS. CO.         13

urges that what actually corresponds to an “oxide layer”
in Doshi is part of the sidewall filament 11, in particular
the portion of the sidewall filament 11 that is near and in
contact with the side of the polysilicon layer 22. Samsung
argues that the Board found that the oxide layer is part of
the sidewall filaments 11 rather than part of the polysili-
con layer 22.
    Contrary to Samsung’s contentions, however, the
Board did not make such findings in reaching its anticipa-
tion decision. In particular, the Board did not make any
explicit finding that an oxide layer is the portion of the
sidewall filament 11 that is near and in contact with the
polysilicon layer 22 nor did it make a finding of where
Doshi’s “oxide layer” resides—either in the sidewall
filaments 11, polysilicon layer 22, or both—if the oxide
layer were to be considered not coextensive with the
sidewall filament 11. Regardless, even assuming arguen-
do that the Board had implicitly made a finding that an
oxide layer is part of the sidewall filament 11 near the
polysilicon layer 22 as urged by Samsung, Doshi’s such
teachings cannot anticipate “forming an oxide layer over
the diffusion region.”
    It is undisputed that the oxidation in Doshi occurs on
the sides of the gate electrode, which itself does not verti-
cally overlap with the diffusion region and is only aligned
on an extended edge above the diffusion region. Regard-
less whether the oxidation of the polysilicon 22 in Doshi
results in an oxide being formed within the sidewall
filament 11, the polysilicon 22, or both, the “oxide layer”
in Doshi, which teeters above on the outermost edge of the
diffusion region, cannot be understood as an oxide layer
formed “over the diffusion region.” The Board rejected
Home’s similar line of argument that the oxide layer in
Doshi is “higher but off to the side.” Final Decision, 2016
Pat. App. LEXIS 7424, at *33–35. It is difficult to discern
the Board’s reasoning and analysis in response, but
14        HOME SEMICONDUCTOR CORP.     v. SAMSUNG ELECS. CO.

regardless, we conclude that the Board erred in its antici-
pation finding because its claim construction was flawed.
    Doshi’s “oxide layer” is only “above” the diffusion re-
gion in the sense that it is higher in position, but is mere-
ly insignificantly overlapping with the diffusion region,
and therefore is not “over the diffusion region.”
“[O]xidizing the sides” of the gate electrode in Doshi is not
“forming an oxide layer over the diffusion region”; it is the
“layer of silicon nitride” that is “deposited overall” in
Doshi. Doshi col. 7 ll. 59–60. Substantial evidence thus
does not support the Board’s finding of anticipation be-
cause Doshi fails to teach forming an oxide layer over the
diffusion region in addition to on the sidewalls of the gate
electrode. Because independent claim 9 is not anticipated
by Doshi, dependent claims 10–14 are also not anticipated
by Doshi.
    Samsung argues in the alternative that a growth of
the oxide layer in Doshi occurs over, and covers, the
diffusion region. Although argued for by Samsung during
the IPR proceeding, the Board did not make a specific
finding on whether an oxide layer grows over and covers
the diffusion region. Even if factual findings to that effect
had been made in favor of Samsung, they would only have
been relevant if Samsung had argued that Doshi inher-
ently teaches the limitation because Samsung had admit-
ted that Doshi does not expressly disclose an oxide layer
covering the diffusion region. Because such argument
was not squarely before the Board, and the Board did not
decide on what appears to be an inherency argument, the
issue is not properly before us.
   We therefore conclude that the Board’s finding that
Doshi anticipates claims 2 and 9–14 of the ’997 patent
was not supported by substantial evidence.
HOME SEMICONDUCTOR CORP.   v. SAMSUNG ELECS. CO.        15

                       CONCLUSION
    For the foregoing reasons, the decision of the Board is
reversed.
                      REVERSED