       NOTE: This disposition is nonprecedential.

  United States Court of Appeals
      for the Federal Circuit
                ______________________

    ROBERT ROZBICKI, MICHAL DANEK, AND
            ERICH KLAWUHN,
                Appellants,

                           v.

  TONY CHIANG, GONGDA YAO, PEIJUN DING,
   FUSEN E. CHEN, BARRY L. CHIN, GENE Y.
    KOHARA, ZHENG XU, AND HONG ZHANG,
                   Appellees.
             ______________________

                      2014-1041
                ______________________

    Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in Interference No.
105,898.
                 ______________________

              Decided: November 14, 2014
                ______________________

    TODD R. WALTERS, Buchanan Ingersoll & Rooney PC,
of Alexandria, Virginia, argued for appellants. With him
on the brief were S. LLOYD SMITH and ERIN M. DUNSTON.

   JOHN R. KENNY, Kenyon & Kenyon LLP, of New York,
New York, argued for appellees. With him on the brief
were MARIA LUISA PALMESE and JOSEPH A. COPPOLA. Of
counsel was GAUDENIS VIDUGIRIS.
2                                       ROZBICKI   v. CHIANG



                 ______________________

        Before DYK and O’MALLEY, Circuit Judges. *
O’MALLEY, Circuit Judge.
    This patent appeal arises from an interference pro-
ceeding before the United States Patent and Trademark
Office Patent Trial and Appeal Board (“PTAB”) relating to
technology for depositing and etching barrier materials on
wafer substrates. The PTAB construed the term “etching”
as “the removal of material to create a pattern.” Relying
on this construction, the PTAB found that U.S. Patent
Application No. 11/733,671 (“the Chiang Application”)
contained adequate written description support for the
lone interference count.
     On appeal, Rozbicki challenges the PTAB’s construc-
tion of “etching” and its written description finding.
Because we agree with the PTAB’s claim construction, we
affirm its written description decision for Chiang claims
31–39, 46, 59–61, 63, 64, 66–71, 83, and 84 as it is sup-
ported by substantial evidence. We vacate and remand
the PTAB’s decision for Chiang claims 47, 49, 51, 53, 55,
57, 76–82, 85, 87, 88, and 90, however, because we find
that the PTAB’s explanation of how the Chiang Applica-
tion describes the “net etching” limitation is inadequate.
                      BACKGROUND
    This technology relates to wafer substrates to make
integrated circuits. The wafer substrates contain semi-
conductor devices that are electrically connected to form
the integrated circuits. Appellee Br. 4. These electrical
connections are made using vias, which are openings in a



    *   Randall R. Rader, who retired from the position of
Circuit Judge on June 30, 2014, did not participate in this
decision.
ROZBICKI   v. CHIANG                                      3



layer of silicon dioxide above the wafer substrate. Id.
These vias are filled with metal to make the electrical
connections. Id. Previously, semiconductor manufactur-
ers used aluminum to make these electrical connections.
Id. Eventually, manufacturers switched to copper, which
has a lower resistivity. Id. This switch, however, re-
quired the placement of a layer of barrier material be-
tween the silicon dioxide and the copper to prevent the
copper from diffusing into the silicon dioxide. Id. Nor-
mally, this barrier material is placed over the silicon
dioxide through a physical vapor deposition process, such
as, sputtering or a chemical vapor deposition pro-
cess. ’977 Patent col. 2 ll. 13–16. Sputtering is a process
where atoms are ejected from a solid target material
towards a substrate by bombarding the target material
with energetic particles. Resputtering is the sputtering of
previously deposited material. Typical barrier materials
can include tantalum, tantalum nitride, tungsten, titani-
um, titanium tungsten, titanium nitride, etc. ’977 Patent
col. 2 ll. 11–13. The identical claims-at-issue on appeal
from both disclosures are directed to a method of deposit-
ing barrier material.
     U.S. Patent No. 6,607,977 (“the ’977 Patent” or “the
Rozbicki Patent”) issued on August 19, 2003. It is titled
“Method of Depositing a Diffusion Barrier for Copper
Interconnect Applications.” ’977 Patent, at [54] (filed
September 26, 2001). As shown in Figure 3C below, the
invention discloses a first step of depositing barrier mate-
rial 325 to provide coverage, then a second step of deposit-
ing additional barrier material and simultaneously
etching a portion of the barrier material deposited in the
first step as seen in Figure 3D.
4                                        ROZBICKI   v. CHIANG




’977 Patent Fig. 3C, 3D. The summary of the invention
states that the result of the steps is a metal diffusion
barrier formed in part by “net etching” in the bottom of
the vias and “net deposition” on the side walls. The
specification describes “net etching” as having an “etch to
deposition ratio” or “E/D” that is greater than 1. The
purpose of this “net etching” is to reduce the resistance of
subsequently formed metal interconnects.
     The Chiang Application relates to “a method of sput-
tering a sculptured coating over the walls of a high aspect
ratio semiconductor feature in a manner which avoids or
significantly reduces the possibility of damage to or
contamination of underlying surfaces.” Joint Appendix
(“J.A.”) 1180. The Chiang Application generally describes
applying a first portion of a sculptured layer using tradi-
tional sputtering or ion deposition sputtering with a low
substrate bias such that a surface onto which said sculp-
tured layer is applied is not eroded away. J.A. 1188. It
then describes applying a subsequent portion of the
sculptured layer using ion deposition sputtering with
sufficiently high substrate bias to sculpture a shape from
said first portion while depositing additional layer mate-
rial. J.A. 1188. Chiang explains that, “[a]fter deposition
ROZBICKI   v. CHIANG                                        5



of a first portion of barrier layer material, the bias voltage
is increased during the deposition of additional barrier
layer material over the feature surface. The application
of increased bias voltage results in the resputtering
(sculpturing) of the first portion of barrier layer or wetting
layer material (deposited at the lower substrate bias
voltage) while enabling a more anisotropic deposition of
newly depositing material.” J.A. 1190. “Availability of
the material which was deposited at the lower bias volt-
age on the surface of a trench or via protects the substrate
surface under the barrier or wetting layer material during
the sputtering deposition at higher bias voltage. This
avoids breakthrough into the substrate by impacting
ionized material which could destroy device functionality.”
J.A. 1190.
      Chiang provides three examples in his application,
 which correspond to the Chiang Application Figures 3 to
  5. The key example is Example 3, describing Figure 5.
6                                         ROZBICKI   v. CHIANG



     This figure discloses an embodiment involving an ini-
tial deposition where a barrier material is applied for 15
seconds without the application of substrate biasing
power, then applying a substrate biasing power of -60V
(250W) while depositing barrier material through ion
deposition plasma for about 45 seconds. J.A. 1200–01.
During this second deposition period, barrier material
from the first deposition period is resputtered, with excess
barrier material being removed and reshaped. J.A. 1201.

     On May 25, 2012, the PTAB declared Interference No.
105,898 between claims 1–73 of the Rozbicki Patent and
claims 31–90 of the Chiang Application. As Chiang copied
its claim language from the Rozbicki Patent, the interfer-
ence included a single count: claim 1 of the ’977 Patent
which is the same as claim 31 of the Chiang Application.
These identical claims state:

    A method for depositing a diffusion barrier and a
    metal conductive layer for metal interconnects on
    a wafer substrate, the method comprising:
    (a) depositing a first portion of the diffusion barri-
    er over the surface of the wafer substrate;
    (b) etching the first portion of the diffusion barrier
    at the bottom of a plurality of vias without fully
    etching through such that an amount of barrier
    material remains at the bottom of the plurality of
    vias, while depositing a second portion of the dif-
    fusion barrier elsewhere on the wafer substrate;
    and
    (c) depositing the metal conductive layer over the
    surface of the wafer substrate such that the metal
    conductive layer contacts the barrier material re-
    maining at the bottom of the plurality of vias;
    wherein at least part of (a) and all of (b) are per-
    formed in the same processing chamber.
ROZBICKI   v. CHIANG                                       7



J.A. 155–166, 178–187 (emphasis added); see also ’977
Patent col. 14 ll. 24–41. For the lone count, the PTAB
accorded Rozbicki benefit back to March 13, 2001, and
Chiang back to November 26, 1997. Accordingly, the
PTAB deemed Rozbicki the junior party and Chiang the
senior party.
    Rozbicki filed a first motion for judgment asserting
that the Chiang Application failed to satisfy the written
description requirement. Rozbicki further filed a second
motion for judgment that Chiang is not entitled to the
benefit of the filing date of any earlier application because
those applications also fail to satisfy the written descrip-
tion requirement. Chiang filed a motion to exclude cer-
tain evidence. 1 On June 26, 2013, the PTAB: (1) granted-
in-part Rozbicki’s motion for failure to meet written
description for Chiang claims 40–45, 48, 50, 2 52, 54, 56,
58, 62, 65, 72–75, 86, and 89, 3 but denied-in-part for
Chiang claims 31–39, 46, 47, 49, 51, 53, 55, 57, 59–61, 63,
64, 66–71, 76–85, 87, 88, and 90; (2) denied Rozbicki’s
second motion on accorded benefit; and (3) granted-in-part
and denied-in-part Chiang’s motion to exclude certain
evidence.



    1   Chiang moved to exclude certain statements from
Rozbicki’s patent and priority application that are repeat-
ed in the Rozbicki expert’s testimony as hearsay. The
PTAB denied this motion on the grounds that the docu-
ments were admissible as proof of what they say. Accord-
ingly, Rozbicki’s expert was allowed to reasonably rely on
these documents. This ruling is not at issue on appeal.
    2   While the PTAB granted Rozbicki’s motion as to
claim 50, that claim was not included in the PTAB’s
summary of dismissed claims. Compare J.A. 19, with J.A.
20.
    3   Chiang is not appealing the PTAB’s finding for
these dependent claims.
8                                         ROZBICKI   v. CHIANG



    Addressing the construction of “etching,” the PTAB
construed the term as requiring “the removal of material
to create a pattern.” J.A. 7. The PTAB then found that
the Chiang Application disclosed sputtering/resputtering
as one way to etch and deposit simultaneously, and point-
ed to Example 3 for disclosing the necessary etching. The
PTAB further found that Chiang taught “net etching”
based on Example 3. J.A. 15. As essentially the same
reasons regarding written description, the PTAB found
priority for Chiang.
    Rozbicki subsequently filed a motion for rehearing.
On July 16, 2013, the PTAB entered its Decision on
Request for Rehearing. While the PTAB reconsidered the
decision, it denied the requested relief. The PTAB stated
that there was nothing that compelled a narrower claim
interpretation. The PTAB stated that the claims only
require “etching,” not “net etching” as described in the
Rozbicki Patent’s written description.         Turning to
Chiang’s disclosure, the PTAB stated that Chiang’s Ex-
ample 3 made sense only if etching occurred in the second
step. The PTAB also stated that it found Rozbicki’s
expert less credible than Chiang’s expert. It then ex-
plained that the independent claims did not require
reducing thickness of the barrier layer and that, even if
they did, Chiang’s second step appears to reduce the
thickness while redistributing the material.
    On July 30, 2013, the PTAB entered Judgment find-
ing that Rozbicki did not have priority, and, consequently,
cancelled claims 1–73 of the ’977 Patent. Rozbicki timely
appealed. This court has jurisdiction pursuant to 28
U.S.C. § 1295.
                       DISCUSSION
                  A. Claim Construction
    This court reviews claim construction de novo. Light-
ing Ballast Control LLC v. Philips Elecs. N. Am., 744 F.3d
ROZBICKI   v. CHIANG                                     9



1272, 1276–77 (Fed. Cir. 2014) (en banc). “[W]hen a party
challenges written description support for an interference
count or the copied claim in an interference, the originat-
ing disclosure provides the meaning of the pertinent claim
language.” Agilent Techs., Inc. v. Affymetrix, Inc., 567
F.3d 1366, 1375 (Fed. Cir. 2009); see also In re Spina, 975
F.2d 854, 856 (Fed. Cir. 1992) (“When interpretation is
required of a claim that is copied for interference purpos-
es, the copied claim is viewed in the context of the patent
from which it was copied.” (citing DeGeorge v. Bernier, 768
F.2d 1318, 1322 (Fed. Cir. 1985))). Consequently, we
review the Chiang claims copied from the Rozbicki Patent
in light of the Rozbicki Patent specification. See Agilent,
567 F.3d at 1375.
    The PTAB construed the term “etching” as the remov-
al of barrier material. Looking at the claim language
itself, the PTAB stated that the claim “simply requires
‘etching’.” J.A. 6. It emphasized that Rozbicki defines
“net etching” in its written description, but only refer-
ences “etching” in the independent claims. The PTAB
pointed out that this supports an inference that the
claims are broader than the preferred embodiment.
Turning to the expert testimony presented by both par-
ties, the PTAB found the testimony of Chiang’s expert,
Dr. Cuomo, more credible than that of Rozbicki’s expert,
Dr. Ruzic, with respect to what the term “etching” re-
quires. Specifically, the PTAB found Dr. Ruzic’s testimo-
ny less credible because the term “net etching” is not an
art-recognized term and introduces imprecision. J.A. 6.
    Rozbicki argues that the PTAB erred in ruling that
“etching” does not require “net etching”—which occurs
when there is more etching than deposition—in all the
claims. He further argues that the PTAB should have
construed etching to require thinning of the barrier layer
at the bottom of the via. Rozbicki also asserts that the
PTAB defined etching without considering the Rozbicki
specification. He points out that the specification “re-
10                                       ROZBICKI   v. CHIANG



peatedly, consistently, and exclusively” teaches reducing
the thickness of the barrier layer previously deposited at
the bottom of the via. Chiang responds that the PTAB
correctly construed the term etching as simply the remov-
al of barrier material. He agrees with the PTAB that the
claim language in the independent claims only requires
“etching,” and not any particular level of etching. Chiang
further states that the specification describes net deposi-
tion where the etch to deposition ratio is less than one,
which refutes the requirement that etching requires “net
etching” or “net removal.” ’977 Patent col. 13 ll. 13–19
(“The magnitude of E/D on the side walls is < 1 . . . . The
side walls receive a net deposition.”).
    We agree with Chiang that the PTAB properly de-
fined etching to require the removal of material, and not
“net etching” or thinning at the bottom of the via. The
claim language states “(b) etching the first portion of the
diffusion barrier at the bottom of a plurality of vias with-
out fully etching through such that an amount of barrier
material remains at the bottom of the plurality of vi-
as.” ’977 Patent col. 14 ll. 30–33. The claim language
itself does not include any requirement of “net etching” or
thinning at the bottom of the via.
     Rozbicki improperly attempts to read limitations into
the claims based on the embodiments described in his
written description, limitations which are absent from the
claim language. The Rozbicki Patent’s written descrip-
tion, however, explicitly describes “net etching” as having
an etch to deposition ratio of greater than 1. Accordingly,
even Rozbicki recognizes that this “net etching” is distin-
guishable from the term “etching.” For example, Rozbicki
claim 27, which corresponds to Chiang claim 47, states:
“wherein (b) comprises a PVD etch/deposition process in
which an RF frequency is applied to the wafer substrate
such that the etch to deposition ratio is greater than 1 in
the bottom of the plurality of vias and less than 1 on the
field.” ’977 Patent col. 15 ll. 44–48 (emphasis added).
ROZBICKI   v. CHIANG                                    11



First, this claim language uses the term “etch” as part of
its description of “net etching” for the bottom of the plu-
rality of vias. Second, this very same claim requires an
etch to deposition ratio less than 1 on the field. If the
term “etching” required “net etching,” then an etch to
deposition ratio less than 1 would not make any sense, or
at least be redundant. Accordingly, this claim language
supports the PTAB’s broader construction of the term
“etching.” Furthermore, despite the ability to include the
term “net etching” or an etch to deposition ratio greater
than 1 in the text of its claims, Rozbicki chose to include
only the term “etching” in its independent claims. Chiang
then copied this broad language into his own claims.
Rozbicki, while attempting to obtain the broadest claim
language possible during prosecution, cannot now im-
properly narrow its language by importing limitations not
supported by the claim language or written description.
For the reasons above, we affirm the PTAB’s claim con-
struction of “etching.”
             B. Written Description Requirement
                         1. Etching
    Rozbicki disputes whether the Chiang Application
provides written description support for the claims-at-
issue. The written description requirement is found in 35
U.S.C. § 112 (2012), which states:
   The specification shall contain a written descrip-
   tion of the invention, and of the manner and pro-
   cess of making and using it, in such full, clear,
   concise, and exact terms as to enable any person
   skilled in the art to which it pertains, or with
   which it is most nearly connected, to make and
   use the same, and shall set forth the best mode
   contemplated by the inventor or joint inventor of
   carrying out the invention.
12                                       ROZBICKI   v. CHIANG



    To satisfy the written description requirement, the
specification must “convey with reasonable clarity to
those skilled in the art that, as of the filing date sought,
he or she was in possession of the [claimed] invention.”
Vas-Cath, Inc. v. Mahurkar, 935 F.2d 1555, 1563–64 (Fed.
Cir. 1991). The properly construed claim must be sup-
ported by the originating specification. Agilent, 567 F.3d
at 1378–79. Satisfying the written description require-
ment is a question of fact that we review for substantial
evidence. Harari v. Lee, 656 F.3d 1331, 1341 (Fed. Cir.
2011) (citing Chen v. Bouchard, 347 F.3d 1299, 1304 (Fed.
Cir. 2003)).
    In light of its claim construction of “etching,” the
PTAB concluded that the Chiang Application sufficiently
described this limitation, which is recited in Chiang
independent claims 31 and 66. Specifically, the PTAB
found the Chiang Application’s discussion of the sputter-
ing/resputtering process, which removes barrier material
at the bottom of the via, satisfied the written description
requirement for “etching.” In support, it looked to Exam-
ple 3 in light of Examples 1 and 2 from the Chiang Appli-
cation. The PTAB explained that the three examples “are
sufficient to indicate to one of ordinary skill that, more
likely than not, the third example achieves its purported
result by offsetting the results of method steps similar to
example 2 with the results of method steps similar to
example 1.” J.A. 11. The PTAB also relied on the testi-
mony of Chiang’s expert, Dr. Cuomo, who explained that
etching results from the biasing substrate, which creates
an electrical field, causing ions to impact on the silicon
substrate and silicon dioxide sidewall, resulting in simul-
taneous sputtering of the surfaces such as through the
second step of Example 3.
    Rozbicki argues that the Chiang Application does not
satisfy the written description requirement. According to
Rozbicki, the written description does not make clear that
etching occurs at the bottom of the via, and Example 3
ROZBICKI   v. CHIANG                                    13



does not necessarily show etching. Chiang responds that
substantial evidence exists based on Example 3 and Dr.
Cuomo’s expert testimony, which the PTAB found more
credible than that of Rozbicki’s expert. Since we agree
with the PTAB’s claim construction, we look to see if the
PTAB’s finding that the Chiang Application sufficiently
described the “etching” limitation is supported by sub-
stantial evidence. We find that it is, and do not find
Rozbicki’s arguments persuasive.
    The Chiang Application generally discloses the re-
moval of material through sputtering/resputtering. It
then provides a step for “applying a subsequent portion of
said sculptured layer using ion deposition sputtering,
with sufficiently high substrate bias to sculpture a shape
from said first portion, while depositing additional layer
material.” J.A. 1188. During this step, “[t]he application
of increased bias voltage results in the resputtering
(sculpturing) of the first portion of barrier layer.” J.A.
1190; see also J.A. 1201. Consequently, the barrier layer
from the first deposition period, which includes the barri-
er layer at the bottom of the via, is resputtered. This
resputtering meets the “etching” requirement.
    Chiang’s expert, Dr. Cuomo, testified that the sputter-
ing/resputtering removes sections of the initially deposit-
ed barrier layer from the bottom of the via. In particular,
he pointed to Example 3 as reproduced from Figure 5 of
the Chiang Application.
14                                      ROZBICKI   v. CHIANG




    Dr. Cuomo testified that Example 3 discloses the
claimed invention, and essentially performs the steps of
Example 2 and then Example 1 consecutively, in that
order. J.A. 2635–40. Example 1 discloses etching as seen
by the breakthrough in the barrier level when sputtering
with a substrate bias. Example 2 discloses sputtering
with no substrate bias, resulting in the deposit of a large
quantity of barrier material at the bottom of the via with
no breakthrough. By performing a first step similar to
Example 2 prior to the step of Example 1, Chiang’s expert
testified that Example 3 prevents breakthrough into the
lower level when etching occurs during the second step
similar to Example 1. J.A. 2639. Furthermore, the
Chiang Application explains that the first deposit layer
“protects the substrate surface . . . during the sputtering
deposition at higher bias voltage” and “avoids break-
through.” J.A. 1190. This concern exists only if the
second step causes etching. Based on the specification of
the Chiang Application and the expert testimony, there is
ROZBICKI   v. CHIANG                                     15



substantial evidence to support the conclusion that the
Chiang Application discloses etching.
    Rozbicki also argues that the Chiang Application only
employs two sequential deposition steps, not an etching
step of the layer at the bottom of the via. In support, he
points to language in the Chiang Application stating that
the steps listed are described as depositing steps for a
barrier layer substance. 4 Chiang disagrees, stating that
the second step in its application inherently includes
etching within the depositing step. As explained by the
PTAB and Chiang’s expert, although the Chiang Applica-
tion lists its steps as depositing steps, this does not
change the fact that the second step in the Chiang Appli-
cation also performs etching.
    Rozbicki contends that the PTAB erred because the
disclosure of sputtering/resputtering does not provide
support for the full scope of the term “etching” in Chiang’s
claims. In Rozbicki’s first motion, he requested “judgment
that Chiang’s involved claims are unpatentable to Chiang
under 35 U.S.C. § 112, first paragraph, as lacking ade-
quate written description.” J.A. 412. The PTAB found
that Rozbicki did not advance a scope argument, instead
arguing only that the Chiang Application failed to de-
scribe a particular embodiment. J.A. 22. The PTAB
addressed this point again in its decision on request for
rehearing. It stated that, “[w]hile the statute encom-
passes a scope argument, it does not follow that Rozbicki
necessarily made a scope argument. As the decision
noted, case law distinguishes scope as a distinct type of


   4    The specific claim language for the second step
states: “applying a subsequent portion of said sculptured
layer using ion deposition sputtering, with sufficiently
high substrate bias to sculpture a shape from said first
portion, while depositing additional layer material.” J.A.
1188.
16                                        ROZBICKI   v. CHIANG



written description problem.” J.A. 40. It further stated
that, “[a]s a matter of due process, Chiang need not
address every theory that Rozbicki could have argued, but
only the argument Rozbicki actually made.” J.A. 40
(footnote omitted). We agree with the PTAB that Rozbicki
did not properly raise a scope argument before the PTAB,
and thus, we find that the PTAB did not err in failing to
address this argument.
    Because substantial evidence supports the PTAB’s
finding that the Chiang Application adequately describes
the “etching” limitation, we affirm the PTAB’s finding
that Chiang claims 31 and 66 meet the written descrip-
tion requirement.      Additionally, since Rozbicki only
argues that Chiang dependent claims 32–39, 46, 59–61,
63, 64, 67–71, 83, and 84 do not meet the written descrip-
tion requirement because the Chiang Application fails to
disclose the “etching” limitation—the same argument we
just rejected—we also affirm the PTAB’s findings as to
these claims. Furthermore, because Rozbicki’s arguments
that Chiang is not entitled to the benefit of each of its
earlier-filed priority application hinges on the written
description challenge, we affirm the PTAB’s finding that
Chiang is entitled to the benefit of each of its earlier-filed
applications for Chiang claims 31–39, 46, 59–61, 63, 64,
66–71, 83, and 84.
                       2. Net Etching
    We do not find, however, that the PTAB adequately
addressed the extent to which the Chiang Application
discloses “an etch to deposition ratio greater than 1 in the
bottom of the plurality of vias,” a limitation which ap-
pears in the remaining claims at issue.
    First, the PTAB did not consider Rozbicki’s expert tes-
timony regarding “net etching.” The only explanation the
PTAB provided as to why it rejected the testimony of
Rozbicki’s expert on this issue was that it did not agree
with his definition of the term “etching.” See J.A. 15 (“Dr.
ROZBICKI   v. CHIANG                                     17



Ruzic’s testimony is entitled to little weight because it is
based on an untenable interpretation of the contested
claim language.”). As such, the PTAB simply ignored Dr.
Ruzic’s testimony regarding what “net etching” is, and the
existence of “etch to deposition ratio greater than 1 in the
bottom of the plurality of vias” solely based on his “unten-
able interpretation” of “etching.” Although the PTAB
stated in its decision on rehearing that it did not overlook
Rozbicki’s expert testimony, which showed that Chiang’s
examples could not result in “an etch to deposition rates
greater than 1,” solely based on its disagreement with his
claim construction position, that is, in fact, what the
PTAB did in its initial decision. J.A. 15, 39. And it did
not cure this problem in its order on reconsideration.
    Second, in addressing the “net etching” limitation, the
PTAB failed to adequately explain how Chiang disclosed
this limitation. The PTAB conceded that “Chiang’s dis-
closure does not describe an . . . etch-to-deposition (E/D)
ratio.” J.A. 18. But it concluded that Chiang discloses the
E/D ratio limitation, because the claim language is, in the
PTAB’s opinion, so broad that Chiang’s general discussion
of “etching at the via bottom while material is deposited
elsewhere, including the field,” sufficiently describes the
contested limitation. J.A. 18. This bare assertion alone,
however, does not suffice as adequate support. Without
any analysis as to how a brief discussion about “etching,”
which can occur without an “etch to deposition ratio
greater than 1 in the bottom of the plurality of vias,” also
discloses this limitation, the PTAB’s conclusion is un-
founded. Therefore, the PTAB’s explanation does not
adequately support the finding that the Chiang Applica-
tion meets the written description requirement for the
limitation of an “etch to deposition ratio greater than 1 in
the bottom of the plurality of vias.”
    Therefore, we vacate the PTAB’s decision regarding
Chiang claims 47, 49, 51, 53, 55, 57, 76–82, 85, 87, 88, and
90 and remand for the PTAB to provide a more detailed
18                                        ROZBICKI   v. CHIANG



explanation of how the Chiang Application’s written
description supports an “etch to deposition ratio greater
than 1 in the bottom of the plurality of via,” including a
discussion of the expert testimony from both parties.
                       CONCLUSION
     For the reasons above, and because we find that
Rozbicki’s remaining arguments are without merit, we
affirm the PTAB’s claim construction, and consequently,
affirm its finding of written description support and
priority for Chiang claims 31–39, 46, 59–61, 63, 64, 66–71,
83, and 84 as it is supported by substantial evidence. We
vacate and remand the PTAB’s decision for Chiang claims
47, 49, 51, 53, 55, 57, 76–82, 85, 87, 88, and 90 for further
proceedings consistent with this opinion.
     AFFIRMED-IN-PART, VACATED-IN-PART, AND
                   REMANDED
