DSS Technology Management, Inc. v. Taiwan Semiconductor Manufacturing Co.

NOTE: This disposition is nonprecedential.

United States Court of Appeals
for the Federal Circuit
______________________

DSS TECHNOLOGY MANAGEMENT, INC.,
Plaintiff-Appellant

v.

TAIWAN SEMICONDUCTOR MANUFACTURING
COMPANY, LTD., TSMC NORTH AMERICA,
SAMSUNG ELECTRONICS CO., LTD., SAMSUNG
ELECTRONICS AMERICA, INC., SAMSUNG
TELECOMMUNICATIONS AMERICA, LLC,
SAMSUNG SEMICONDUCTOR, INC., SAMSUNG
AUSTIN SEMICONDUCTOR, L.L.C.,
Defendants-Appellees
______________________

2015-1684
______________________

Appeal from the United States District Court for the
Eastern District of Texas in No. 2:14-cv-00199-RSP,
Magistrate Judge Roy S. Payne.
______________________

Decided: March 22, 2016
______________________

CHRISTIAN JOHN HURT, Nix Patterson & Roach LLP,
Irving, TX, argued for plaintiff-appellant. Also represent-
ed by DEREK TOD GILLILAND, Daingerfield, TX; WILLIAM
ELLSWORTH DAVIS III, The Davis Firm, PC, Longview, TX.
2 DSS TECH. MGMT., INC. v. TAIWAN SEMICONDUCTOR MFG. CO.

SCOTT A. CUNNING II, Haynes & Boone, LLP, Wash-
ington, DC, argued for defendants-appellees Taiwan
Semiconductor Manufacturing Company, Ltd., TSMC
North America. Also represented by DAVID H. HARPER,
DEBRA JANECE MCCOMAS, STEPHANIE SIVINSKI, Dallas,
TX; KAREN S. PRECELLA, Fort Worth, TX.

JARED BOBROW, Weil, Gotshal & Manges LLP, Red-
wood Shores, CA, argued for defendants-appellees Sam-
sung Electronics Co., Ltd., Samsung Electronics America,
Inc., Samsung Telecommunications America, LLC, Sam-
sung Semiconductor, Inc., Samsung Austin Semiconduc-
tor, L.L.C. Also represented by CHRISTOPHER MARANDO,
Washington, DC; ALLEN FRANKLIN GARDNER, MICHAEL
EDWIN JONES, Potter Minton PC, Tyler, TX.
______________________

Before TARANTO, CLEVENGER, and HUGHES, Circuit Judg-
es.
TARANTO, Circuit Judge.
DSS Technology Management, Inc. owns U.S. Patent
No. 5,652,084, which describes and claims methods of
making patterns in semiconductor wafers. DSS sued a
number of companies, alleging that they manufacture
products by using processes covered by claims 1–7 and 10
the ’084 patent or sell products made by such processes.
After the district court construed the claims, the parties
stipulated to a judgment of noninfringement. DSS ap-
peals the district court’s construction of the term “pat-
terned layer.” DSS Tech. Mgmt., Inc. v. Taiwan
Semiconductor Mfg. Co., No. 2:14-CV-199-RSP, 2015 WL
1737732, at *3–6 (E.D. Tex. Apr. 9, 2015). We affirm.
BACKGROUND
The ’084 patent discloses a lithographic patterning
process “to provide for a relatively reduced pitch for
DSS TECH. MGMT., INC. v. TAIWAN SEMICONDUCTOR MFG. CO. 3

features of a patterned layer.” ’084 patent, col. 1, lines
40–41. In the description of the prior art, the ’084 patent
describes a typical lithography process: First, “photoresist
is deposited over the layer to be patterned and is exposed
to ultraviolet radiation through a mask that defines the
pattern to be formed in the photoresist.” Id., col. 1, lines
19–22. After irradiation, “[t]he photoresist is then devel-
oped to form a patterned photoresist layer over the under-
lying layer to be patterned. Those portions of the
underlying layer that are not covered by photoresist may
then be etched using suitable etch techniques and chemis-
tries.” Id., col. 1, lines 22–26. By such etching, “[t]he
pattern in the photoresist is [ ] replicated in the underly-
ing layer.” Id., col. 1, lines 26–27.
According to the patent, however, the described con-
ventional lithography methods “limit the size and density
with which semiconductor devices may be fabricated.”
Id., col. 1, lines 28–30. The patent describes a purported-
ly novel two-stage process to enable smaller, denser
fabrication. In the first stage, “a first imaging layer is
formed over the semiconductor wafer,” “[t]he first imaging
layer is patterned in accordance with a first pattern to
form a first patterned layer,” and that “patterned layer is
stabilized.” Id., col. 1, lines 49–52. Then “[a] second
imaging layer is formed over the first patterned layer
such that the first patterned layer is surrounded by the
second imaging layer. The second imaging layer is pat-
terned in accordance with a second pattern to form a
second patterned layer.” Id., col. 1, lines 52–56. The
result of the process is a “single patterned layer [ ] formed
from the patterning of [the first] imaging layer . . . and
the subsequent patterning of [the second] imaging layer.”
Id., col. 7, lines 38–40. The resulting (single, unified)
patterned layer may then “serve[ ] as a mask in pattern-
ing an underlying layer,” so the pattern is “replicated in
the underlying layer.” Id., col. 12, lines 45–53.
Claim 1, the only independent claim at issue, states:
4 DSS TECH. MGMT., INC. v. TAIWAN SEMICONDUCTOR MFG. CO.

1. A lithography method for semiconductor
fabrication using a semiconductor wafer, compris-
ing the steps of:
(a) forming a first imaging layer over the semi-
conductor wafer;
(b) patterning the first imaging layer in accord-
ance with a first pattern to form a first pat-
terned layer having a first feature;
(c) stabilizing the first patterned layer;
(d) forming a second imaging layer over the
first pattern layer; and
(e) patterning the second imaging layer in ac-
cordance with a second pattern to form a sec-
ond patterned layer having a second feature
distinct from the first feature, wherein the
second patterned layer and the first patterned
layer form a single patterned layer, and
wherein the first and second features which
are formed relatively closer to one another
than is possible through a single exposure to
radiation.
Id., col. 13, lines 6–24. Claims 2 and 3 each depend on
claim 1, with claim 2 adding that “the first imaging layer
includes a positive photoresist” and claim 3 adding that
“the second imaging layer includes a positive photoresist.”
Id., col. 13, lines 25–28. Claims 4 and 5, which also
depend on claim 1, add limitations to the patterning
steps. Claim 4 reads:
4. The method of claim 1, wherein the pattern-
ing step (b) includes the steps of:
(i) exposing a portion of the first imaging layer
to radiation; and
DSS TECH. MGMT., INC. v. TAIWAN SEMICONDUCTOR MFG. CO. 5

(ii) developing the first imaging layer such that
the exposed portion dissolves to form the first
patterned layer.
Id., col. 13, lines 29–35. Claim 5 adds the same steps to
patterning step (e). Id., col. 13, lines 36–43.
DSS brought the present patent-infringement suit
against Taiwan Semiconductor Manufacturing Company,
Ltd., TSMC North America, TSMC Development, Inc.,
Samsung Electronics Co., Ltd., Samsung Electronics
America, Inc., Samsung Telecommunications America,
LLC, Samsung Semiconductor, Inc., Samsung Austin
Semiconductor L.L.C., and NEC Corporation of America. 1
DSS alleged that the defendants manufacture semicon-
ductor products using processes covered by the ’084
patent or sell products made by such processes.
The district court construed several claim terms. It
adopted the parties’ agreed-to constructions that the first
imaging layer is “a first layer of photoresist or other
radiation-sensitive material” and the second imaging
layer is “a second layer of photoresist or other radiation-
sensitive material.” DSS, 2015 WL 1737732, at *3. The
parties also agreed to the district court’s proposal that
“patterning the [first/second] imaging layer” means “ex-
posing an imaging layer to radiation in accordance with a
specific pattern and developing the imaging layer so that
portions of the imaging layer laying outside of the pattern
are dissolved in the developer, thereby forming patterned
portions and spaces of the imaging layer.” Id. (bracketed
material in original). Then the court adopted the claim
construction at issue here: “first patterned layer having a
first feature” and “second patterned layer having a second

1 TSMC Development, Inc. and NEC Corporation of
America are not appellees in this court because they
settled with DSS.
6 DSS TECH. MGMT., INC. v. TAIWAN SEMICONDUCTOR MFG. CO.

feature,” the court ruled, mean, respectively, “a layer
containing the portions and spaces of the [first/second]
imaging layer that remain after the [first/second] pattern-
ing step.” Id. at *6 (bracketed material in original).
In light of the district court’s claim construction, the
parties stipulated to a judgment of noninfringement. The
stipulation explained the reason: “the layer alleged by
DSS to be the ‘first patterned layer having a first feature’
(namely, a layer underlying the first imaging layer) does
not contain the portions and spaces of the first imaging
layer that remain after exposure and development of the
first imaging layer.” J.A. 39 (emphasis added). The
district court entered a judgment of noninfringement for
defendants and dismissed the defendants’ other claims,
counterclaims, and defenses without prejudice.
DSS appeals. We have a final judgment before us.
See Atlas IP, LLC v. Medtronic, Inc., 809 F.3d 599, 604–05
(Fed. Cir. 2015). We have jurisdiction under 28 U.S.C.
§ 1295(a)(1).
DISCUSSION
We review a district court’s claim construction de novo
where, as here, it is not based on any evidence about
extra-patent understandings of language or other facts.
See Avid Tech., Inc. v. Harmonic, Inc., 812 F.3d 1040,
1044–45 (Fed. Cir. 2016).
DSS disputes the construction of “patterned layer.”
As their noninfringement stipulation evinces, the parties
here agree on the meaning of the district court’s construc-
tion. Under that construction, the patterned layer con-
sists of material of the imaging layer itself—what remains
(material and spaces) after the patterning process has
removed some of the material—and cannot include other
material configured according to the pattern. We con-
clude that the district court’s construction is correct.
DSS TECH. MGMT., INC. v. TAIWAN SEMICONDUCTOR MFG. CO. 7

The language of the claim—“patterning the first imag-
ing layer in accordance with a first pattern to form a first
patterned layer”—points strongly toward the district
court’s construction. It indicates that the first patterned
layer is the immediate result of performing the patterning
process itself, not of that process plus an additional un-
claimed process. The claim does not identify any steps in
the creation of the patterned layer apart from patterning.
And DSS does not dispute the district court’s construction
of “patterning” to mean “exposing an imaging layer to
radiation in accordance with a specific pattern and devel-
oping the imaging layer so that portions of the imaging
layer laying outside of the pattern are dissolved in the
developer, thereby forming patterned portions and spaces
of the imaging layer.” DSS, 2015 WL 1737732, at *3.
Patterning involves applying a pattern to the imaging
layer, irradiating the imaging layer, and developing the
imaging layer to remove portions of the imaging layer. In
the absence of any identification of any other steps, the
immediate result of “patterning” is the “patterned layer,”
which is necessarily the remaining material (and spaces)
of the imaging layer.
That the claim uses two terms (“imaging layer,” “pat-
terned layer”) to refer to the same material does not
detract from this conclusion. DSS itself agrees that the
patterned layer can be made of the same material as the
imaging layer, fully answering any objection about differ-
ent terminology for the same material. The terms merely
refer to the same material at different stages of the pro-
cess.
The specification’s description of the patterning pro-
cess supports the district court’s understanding that the
patterned layer is formed out of the same material as the
imaging layer. The imaging layer is made of a radiation-
sensitive material, such as “a suitable positive photore-
sist, . . . a suitable negative photoresist, a suitable radia-
tion-sensitive polyimide, or other suitable radiation-
8 DSS TECH. MGMT., INC. v. TAIWAN SEMICONDUCTOR MFG. CO.

sensitive materials for example.” ’084 patent, col. 3, lines
34–42 (first imaging layer); see id., col. 5, line 66, through
col. 6, line 8 (second imaging layer). The imaging layer is
patterned in accordance with a pattern to form a pat-
terned layer according to the following steps, applicable to
patterning either imaging layer. See id., col. 3, lines 49–
51; id., col. 6, lines 12–14. The imaging layer is first
“exposed through the first mask using any suitable form
of radiation.” Id., col. 3, lines 65–66; see id., col. 6, lines
26–27. The mask blocks radiation, such that some por-
tions of the layer are exposed to radiation and some are
not. Id., col. 3, lines 54–64; see id., col. 6, lines 23–25.
The imaging layer is then “developed in a suitable devel-
oper to form a first patterned layer.” Id., col. 4, lines 5–6;
see id., col. 6, lines 51–53. When the imaging layer is
made of positive-tone material, “[t]hat portion of imaging
layer 220 that has not been exposed to radiation is rela-
tively insoluble in the developer, and thus remains to
form first patterned layer 232.” Id., col. 4, lines 9–12; see
id., col. 6, lines 56–59. Conversely, when the imaging
layer is made of negative-tone material, “[t]hat portion of
imaging layer 220 exposed to radiation through the first
mask is relatively insoluble in the developer and thus
remains to form first patterned layer 232. That portion of
imaging layer 220 that has not been exposed to radiation
is soluble in the developer and is thus dissolved from
imaging layer 220.” Id., col. 4, lines 24–29; see id., col. 7,
lines 9–14. This description of the process is naturally
read to be treating the “patterned layer” as what remains
of the imaging layer.
More generally, the specification consistently de-
scribes the patterned layer as what remains of the imag-
ing layer. See id., col. 9, lines 53–63 (“For step 350 of
FIG. 6, the imaging layer is developed to form a patterned
layer. Imaging layer 420 may be developed in any suita-
ble developer to form a patterned layer that includes
portions 431, 432, and 433 as illustrated in FIG. 11. As
DSS TECH. MGMT., INC. v. TAIWAN SEMICONDUCTOR MFG. CO. 9

portions 431, 432, and 433 of imaging layer 420 have been
stabilized, portions 431, 432, and 433 are relatively insol-
uble in developer and thus undergo relatively minimal, if
any, dissolution. Portions 431, 432, and 433 thus remain
to form features 431, 432, and 433 for the patterned layer
after development. The remaining portion of imaging
layer 420 is dissolved from imaging layer 420 in the
developer.”); id., col. 12, lines 4–17 (“For step 540 of FIG.
12, the imaging layer is developed to form a patterned
layer. . . . That portion of imaging layer 620 that has not
been exposed to radiation is also relatively insoluble in
the developer, and thus remains to form features 631 and
633 for the patterned layer.”).
Although DSS points to two related passages of the
specification as contrary to the district court’s construc-
tion, we think that those passages are actually supportive
of that construction. One passage, in the description of
the prior art, states that “photoresist is deposited over the
layer to be patterned and is exposed to ultraviolet radia-
tion through a mask.” Id., col. 1, lines 19–22. After
irradiation, the photoresist is “developed to form a pat-
terned photoresist layer over the underlying layer to be
patterned.” Id., col. 1, lines 22–24. Those steps are
similar to steps claimed in the patent—forming an imag-
ing layer and patterning that imaging layer to form a
patterned layer. The passage then specifies additional
steps through which the patterned photoresist layer can
be used to pattern an underlying layer: “Those portions of
the underlying layer that are not covered by photoresist
may then be etched using suitable etch techniques and
chemistries. The pattern in the photoresist is thus repli-
cated in the underlying layer.” Id., col. 1, lines 24–27.
Although this passage describes creating a pattern in an
underlying layer, it notably identifies additional steps,
described in different language, for doing so: suitable
etching techniques and chemistries for replicating the
pattern. That passage tends to reinforce, rather than
10 DSS TECH. MGMT., INC. v. TAIWAN SEMICONDUCTOR MFG. CO.

undermine, the distinction between the “patterned layer”
immediately created by patterning the imaging layer and
transferring the pattern to some other layer.
This understanding is supported by a related passage
near the end of the written description, which explains
that the claimed methods “may be used, for example, to
form a single patterned layer that serves as a mask in
patterning an underlying layer, such as layers 210, 410,
and 610 respectively.” Id., col. 12, lines 45–48. The
specification states that “[t]he underlying layer may be
patterned using a suitable etch technique and chemistry,”
such that “the pattern in the mask layer, such as the
single patterned layer illustrated in FIGS. 5, 11, and 16,
becomes replicated in the underlying layer.” Id., col. 12,
lines 48–53. Like the prior-art passage discussed above,
this passage, by its language, reinforces the distinction
between the patterned layer as what remains of the
imaging layer as a result of its being patterned and an
underlying layer that has been subjected to additional
steps for transferring the pattern.
Principles favoring claim constructions that preserve
differentiation of scope among different claims do not
defeat the district court’s construction of claim 1. Claims
4 and 5 provide additional details for patterning steps (b)
and (e) of claim 1. Id., col. 13, lines 29–43. Claim 4
requires patterning step (b) to include “(i) exposing a
portion of the first imaging layer to radiation; and (ii)
developing the first imaging layer such that the exposed
portion dissolves to form the first patterned layer.” Id.,
col. 13, lines 29–35 (emphasis added). Claim 5 requires
the same steps for patterning step (e), in which the second
imaging layer is patterned. Id., col. 13, lines 36–43.
Claims 4 and 5 require that the imaging layer is positive-
tone—that is, the material becomes more soluble upon
exposure to radiation. See id, col. 3, line 54, through col.
4, line 12 (describing patterning a positive-tone imaging
material). In contrast, the parties agree that claim 1
DSS TECH. MGMT., INC. v. TAIWAN SEMICONDUCTOR MFG. CO. 11

covers both positive- and negative-tone materials. Oral
Arg. at 14:47–15:07, 17:55–18:04. Under the district
court’s claim construction, therefore, claims 4 and 5 are
different in scope from—narrower than—claim 1.
DSS suggests that this understanding of claims 4 and
5 cannot be correct because it renders them equivalent in
scope to claims 2 and 3, which respectively require the
first and second imaging layer to be a positive “photore-
sist.” But while claims 2 and 3 require the imaging-layer
material to be a positive photoresist, claims 4 and 5
require only that “the exposed portion dissolves” after
irradiation, indicative of a positive-tone material. DSS
does not argue that all positive-tone materials are positive
photoresists. And the specification is consistent with the
understanding that not all radiation-sensitive materials
are photoresists. ’084 patent, col. 3, lines 54–56 (“suitable
positive photoresist or a suitable positive-tone radiation-
sensitive polyimide”); cf. id., col. 3, lines 41–42 (“suitable
negative photoresist, a suitable radiation-sensitive polyi-
mide, or other suitable radiation-sensitive materials for
example”). The parties’ agreed-to construction of “imag-
ing layer” similarly treats photoresist as a proper subset
of radiation-sensitive materials, as opposed to an umbrel-
la term that encompasses all radiation-sensitive materi-
als. See DSS, 2015 WL 1737732, at *3. Because claims 4
and 5 recite positive-tone materials, while claims 2 and 3
recite positive photoresists, there is a difference in scope
under the district court’s construction of “patterned
layer.” Accordingly, there is no claim-differentiation basis
for rejecting that construction.
CONCLUSION
For the foregoing reasons, we conclude that the dis-
trict court correctly construed the claims, and we affirm
the district court’s judgment of noninfringement.
AFFIRMED