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`Paper 28
`Entered: January 21, 2015
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`Trials@uspto.gov
`571-272-7822
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`UNITED STATES PATENT AND TRADEMARK OFFICE
`____________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`____________
`
`OSRAM GMBH,
`Petitioner,
`
`v.
`
`E. FRED SCHUBERT,
`Patent Owner.
`____________
`
`Case IPR2013-00459
`Patent 6,294,475 B1
`
`____________
`
`
`
`Before JENNIFER S. BISK, GREGG I. ANDERSON, and
`MATTHEW R. CLEMENTS, Administrative Patent Judges.
`
`ANDERSON, Administrative Patent Judge.
`
`FINAL WRITTEN DECISION
`35 U.S.C. § 318(a) and 37 C.F.R. § 42.73
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`I. BACKGROUND
`A. Introduction
`On July 19, 2013, OSRAM GmbH (“Petitioner”) filed a petition
`requesting inter partes review of claims 1, 2, 4, 11–14, and 16 of
`U.S. Patent No. 6,294,475 B1 (Ex. 1001, “the ’475 patent”). Paper 3
`(“Pet.”). We instituted trial on all challenged claims 1, 2, 4, 11–14, and 16
`of the ’475 patent on certain grounds of unpatentability alleged in the
`Petition. Paper 11 (“Dec. Inst.”).
`After institution of trial, E. Fred Schubert (“Patent Owner”) filed a
`Patent Owner Response. Paper 18 (”PO Resp.”). Petitioner filed a Reply.
`Paper 21 (“Pet. Reply”). An oral hearing was held on October 15, 2014.
`The transcript of the hearing has been entered into the record. Paper 27
`(“Tr.”).
`We have jurisdiction under 35 U.S.C. § 6(c). This final written
`decision is issued pursuant to 35 U.S.C. § 318(a). We have considered all
`the evidence of record, including arguments made at the oral hearing. We
`conclude that Petitioner has failed to show by a preponderance of the
`evidence that claims 1, 2, 4, 11–14, and 16 of the ’475 patent are
`unpatentable.
`
`B. Related Proceedings
`The ’475 Patent is involved in co-pending cases captioned E. Fred
`Schubert v. OSRAM GmbH., Case No. 12-cv-923-GMS (D. Del) and E. Fred
`Schubert v. Koninklijke Philips Electronics N.V., Case No. 12-cv-924-GMS
`(D. Del). Pet. 1.
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`C. The ’475 Patent
`The ’475 Patent relates to a method for processing a III-Nitride
`epitaxial layer system on a substrate. Ex. 1001, Abstract. III-Nitride
`epitaxial layer systems include gallium nitride (“GaN”). Id. III-Nitrides are
`used for producing light-emitting devices including light-emitting diodes
`(“LEDs”) and lasers. Id. at 1:24–27.
`GaN has a hexagonal crystalline structure (“HCP”) where the top
`surface is the c-plane or <0001>.1 Ex. 1001, 3:9–17. The layer of atoms
`that lies parallel to a basal plane is the c-plane of the crystal. Ex. 1003 ¶ 31.
`GaN may be grown on a c-plane sapphire substrate. Ex. 1001, 3:9–17.
`The ’475 Patent discloses that the c-plane of GaN was impervious to
`all of the chemicals with which etching had been attempted. Id. at 3:21–23.
`The ’475 patent describes that by employing an initial processing step, non-
`c-planes could be etched crystallographically by molten potassium
`hydroxide (“KOH”). Id. at 3:19–21.
`The ’475 Patent discloses a two-step process to achieve
`crystallographic etching on non-c-plane surfaces. Ex. 1001, 2:17–23; 3:52–
`64. The process is disclosed in Figure 3, which is reproduced below.
`
`
`1 According to the testimony of Professor James R. Shealy (“Shealy
`Declaration,” Ex. 2002), the various brackets associated with the four Miller
`indices are interpreted as follows: parentheses ( ) denote a specific plane;
`curly brackets { } denote a set of planes with equivalent symmetry; square
`brackets [ ] denote a specific crystal direction; and angle brackets < > denote
`a set of crystal directions normal to planes with equivalent symmetry. Ex.
`2002 ¶ 36.
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`Figure 3 shows at first block 300 an exposing step, which step
`removes material to expose the non-c-plane surfaces of a GaN epitaxial layer
`system. Ex. 1001, 3:52–59. The exposing step uses a known method, such
`as reactive ion etching in chlorine-based plasma, photoelectrochemical
`(“PEC”) etching in a KOH solution, or cleaving. Id. Crystallographic
`etching step 302 includes immersing the epitaxial layer system in a wet
`chemical etch, such as phosphoric acid, molten KOH, KOH dissolved in
`ethylene glycol, sodium hydroxide dissolved in ethylene glycol, tetraethyl
`ammonium hydroxide, or tetramethyl ammonium hydroxide. Id. at 2:27–33.
`Step 302 produces a smooth crystallographic surface. Id. at 3:59–62.
`Figures 9A–9C show how the process is used to make a laser diode.
`Figures 9A–9C are reproduced below.
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`As shown in Figures 9A–9C, mask 900 is deposited initially on III-
`Nitride device structure 902, which is configured on sapphire substrate 904.
`Ex. 1001, 5:3–5, Fig. 9A. A reactive ion etch is performed, leaving rough,
`non-vertical facets 906 in the structure. Id. at 5:5–6, Fig. 9B. Then a
`crystallographic etch produces atomically smooth vertical facets 908, 910.
`Id. at 5:6–7, Fig. 9C.
`
`D. Illustrative Claims
`Claims 1, 11, and 13 are the three independent claims of the
`challenged claims that illustrate the claimed subject matter. Claims 1, 11,
`and 13 are reproduced below:
`1. A method of processing a III-Nitride epitaxial layer system
`provided on a substrate, comprising:
`exposing non-c-plane surfaces of said III-Nitride
`epitaxial layer system; and
`crystallographically etching said epitaxial layer system in
`order to obtain crystallographic plane surfaces.
`11. A method of processing a III-Nitride epitaxial layer system
`comprising:
`providing a III-Nitride epitaxial layer system on a
`substrate; and
`wet chemical crystallographic etching said epitaxial
`system along non-c-plane crystal directions.
`13. A method of processing a III-Nitride epitaxial layer system
`comprising:
`providing a III-Nitride epitaxial layer system on a
`substrate; and
`crystallographically etching said epitaxial layer system
`by immersing said epitaxial layer system into a liquid chemical.
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`Reference
`Akasaki
`
`Sonobe3
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`E. Prior Art References Supporting Unpatentability
`Description
`Publication Date Exhibit No.
`Japanese Published
`Feb. 13, 1998
`Ex. 1005
`Application H10-41585
`Akasaki2 Translation of Akasaki
`Sonobe
`Japanese Published
`Application No. H8-
`255952
`Translation of Sonobe
`
`
`
`F. The Pending Grounds of Unpatentability
`Claims
`Grounds
`Reference[s]
`1, 2, 4, 11–14, and 16
`§ 102(a)
`Akasaki
`
`Feb. 13, 1998
`Oct. 1, 1996
`
`Ex. 1006
`Ex. 1008
`
`Oct. 1, 1996
`
`Ex. 1009
`
`1, 2, 4, 11–14, and 16
`
`
`§ 102(b)
`
`Sonobe
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`II. ANALYSIS
`A. Claim Construction
`1. Principals of Law
`We interpret claims of an unexpired patent using the broadest
`reasonable construction in light of the specification of the patent in which
`they appear. See 37 C.F.R. § 42.100(b); Office Patent Trial Practice Guide,
`77 Fed. Reg. 48,756, 48,766 (Aug. 14, 2012).
`
`
`2 All references in this decision to “Akasaki” are to the English translation
`(Ex. 1006) of the Japanese Published Application.
`3 All references in this decision to “Sonobe” are to the English translation
`(Ex. 1009) of the Japanese Published Application.
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`2. “substrate”
`The term “substrate” is recited in all three independent claims 1, 11,
`and 13. Substrate appears in the preamble of claim 1 and as part of claimed
`steps of claims 11 and 13. For example, claim 11 recites: “providing a III-
`Nitride epitaxial layer system on a substrate.” As used in claim 1,
`“substrate” does not provide antecedent basis for any ensuing claim terms
`and is not a limitation. See, e.g., C.R. Bard, Inc. v. M3 Sys., Inc., 157 F.3d
`1340, 1350 (Fed.Cir. 1998).
`Patent Owner argued in its Preliminary Response that “substrate” had
`a meaning to the person of ordinary skill as the substrate upon which
`epitaxial layers are supported. Prelim. Resp. 7–11 (citing Ex. 20024 ¶¶ 19–
`25). We adopted Patent Owner’s proposed construction in the Decision to
`Institute. Dec. Inst. 9–10.
`Neither party objects to the construction of “substrate” from the
`Decision to Institute. The ’475 patent does not define the term “substrate.”
`On this record, we are not presented with any reason to change our
`construction of “substrate” from the Decision to Institute and we find that
`“substrate” has its ordinary and customary meaning as would be understood
`by one with ordinary skill. Accordingly, “substrate” means “support
`material for epitaxial layers.” Id.
`3. “epitaxial layer system”
`The term “epitaxial layer system” is recited in all three independent
`claims. For example, claim 1 recites: “exposing non-c-plane surfaces of
`said III-Nitride epitaxial layer system.”
`
`
`4 Dr. Shealy’s Declaration, Exhibit 2002, was created for and submitted in
`the related district court action between the parties.
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`Neither party objects to our construction of “epitaxial layer system”
`from the Decision to Institute. Dec. Inst. 10–11. The McGraw-Hill
`Dictionary of Scientific & Technical Terms 690 (5th ed. 1994) defines
`“epitaxial layer” as “[a] semiconductor layer having the same crystalline
`orientation as the substrate on which it is grown.” Ex. 1028. The
`Specification is consistent with the dictionary definition. See Ex. 1001,
`3:15–17. On this record, we are not presented with any reason to change our
`construction of “epitaxial layer system” substrate” from the Decision to
`Institute and thus we construe “epitaxial layer system” as “at least one
`semiconductor layer having a crystalline relationship to the substrate on
`which it is grown.” See Dec. Inst. 10–11.
`4. “non-c-plane”
`The term “non-c-plane” is recited in independent claims 1 and 11, but
`not claim 13. For example, claim 1 recites: “exposing non-c-plane surfaces
`of said III-Nitride epitaxial layer system.”
`Neither party objects to our construction of “non-c-plane” from the
`Decision to Institute. Dec. Inst. 13–14. According to the testimony from the
`Declaration of Dr. Christian M. Wetzel, Petitioner’s witness (“Wetzel
`Declaration,” Exhibit 1003), a person of ordinary skill with knowledge of
`the GaN crystal structure would have understood non-c-plane as something
`other than two c-planes, which are a positive c-plane (0001) (on the top
`surface) and a negative c-plane (000͞1) on the bottom surface). Ex. 1003 ¶
`62. The file history of the ’475 patent also describes non-c-planes as passing
`“vertically through the c[-]plane.” Ex. 1002, 116–117. The ’475 patent
`describes the c-plane as the “top surface of the GaN crystal.” Ex. 1001,
`3:21–23. The ’475 patent also uses the Miller indices nomenclature {0001}
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`in describing the c-plane. Id. at 4:6–8. Dr. Shealy testifies that, in the case
`of GaN, the nomenclature {0001} limits the designated plane to the positive
`c-plane. Ex. 2002 ¶ 48.
`We are not presented with any reason to change our construction of
`“epitaxial layer system” substrate” from the Decision to Institute and thus
`construe “non-c-plane” as “a plane other than the positive c-plane (0001).”
`Dec. Inst. 13–14.
`5. “crystallographic etching/crystallographically etching”
`The terms “crystallographic etching” or “crystallographically etching”
`are recited in all three independent claims. For example, claim 1 recites:
`“crystallographically etching said epitaxial layer system.”
`In the Decision to Institute, we construed “crystallographic
`etching/crystallographically etching” as “etching that proceeds in directions
`dictated by the crystallographic planes of the material being etched.” Dec.
`Inst. 11–12. Both parties cited Donnelly (Exhibit 1019) as describing the
`interaction between an etchant and “III-IV material” as “differential
`crystallographic etching, i.e., etching that proceeds in directions dictated by
`the crystallographic planes of the material being etched at a rate which
`strongly depends on the particular plane.” See Pet. 14–15 (citing Ex. 1019,
`3:7–12); Prelim. Resp. 14.
`In its Response, Patent Owner states it is “essentially in agreement
`with the Board’s construction.” PO Resp. 15. Nonetheless, Patent Owner
`proposes a different construction as follows: “etching (removal of material)
`that proceeds in directions dictated by the crystallographic planes of the
`material being etched at a rate which depends on the particular plane
`(defect-revealing etching is not crystallographic etching).” Id. (Board
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`construction from Decision to Institute in bold and italics). Patent Owner’s
`construction offers additional clarifications to our construction from the
`Decision to Institute. Id. at 15–18.
`Petitioner contends that the ’475 patent discloses in Figure 2 “etching
`that proceeds in directions dictated by the crystallographic planes of GaN at
`defect sites.” Pet. Reply 2. Petitioner contends that “crystallographic
`etching” includes what is shown in Figure 2, the etching of defects. Id. at 3.
`Thus, Petitioner argues that “crystallographic etching” does not require
`“pristine crystal” and etching of defect pits which include the crystal
`symmetry of GaN are encompassed by “crystallographic etching.” Id. at 4.
`The ’475 patent does not explicitly define “crystallographic etching.”
`Patent Owner’s clarifications are extraneous limitations unnecessary for the
`purpose of making sense of the claim. See, e.g., In re Paulsen, 30 F.3d
`1475, 1480 (Fed. Cir. 1994). Neither do we accept Petitioner’s proposal that
`defect etching should be specifically included in our construction because
`defect etching could be, but is not necessarily, “crystallographic etching.”
`On this record, we are not presented with any reason to change our
`construction of “crystallographic etching” from the Decision to Institute and
`construe “crystallographic etching/crystallographically etching” as “etching
`that proceeds in directions dictated by the crystallographic planes of the
`material being etched.” Dec. Inst. 11–12.
`6. “crystallographic plane surfaces”
`We have not previously considered nor provided a construction for
`“crystallographic plane surfaces.” The term “crystallographic plane
`surfaces” is present in claim 1, which recites “crystallographically etching
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`said epitaxial layer system in order to obtain crystallographic plane
`surfaces.”
`When asked for a construction of “crystallographic plane
`surfaces” at final hearing, Petitioner stated the term means “the
`smooth surfaces that are crystallographic planes that are yielded in the
`-- in both Akasaki and in Sonobe.” Tr. 8:12–15. Patent Owner, in
`response to the same question, said, “a crystallographic plane surface
`is one that is, first of all, produced by crystallographic etching. And it
`refers to, in that particular plane, a smooth plane surface that reflects
`the intrinsic planes in the crystal.” Tr. 31:16–20. The language of
`claim 1 requires that “crystallographic plane surfaces” result from
`crystallographic etching.
`We thus construe “crystallographic plane surfaces” to mean “a
`smooth plane surface resulting from crystallographic etching.”
`B. Issues for Review
`1. Summary of Remaining Issues
`We instituted trial on claims 1, 2, 4, 11–14, and 16 on two grounds.
`Based on the information provided in the Petition, we determined that
`Petitioner had demonstrated a reasonable likelihood of showing that the
`claims were anticipated under 35 U.S.C. § 102(a) by Akasaki, and under 35
`U.S.C. § 102(b) by Sonobe. Dec. Inst. 23.
`Patent Owner does not dispute that the vertical dry etch used in both
`Akasaki and Sonobe exposed non-c-planes of GaN. PO Resp. 3. Patent
`Owner states the critical issue is whether the wet etching of Akasaki and
`Sonobe discloses, expressly or inherently, crystallographic etching of the
`subject epitaxial layer system. Id. at 3, 12; Tr. 53:1–4. Petitioner agrees that
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`the critical issue in this case is whether Akasaki and Sonobe disclose
`crystallographic etching under the broadest reasonable claim interpretation.
`Pet. Reply 1; Tr. 5:4–8.
`We have reviewed the Petition, Petitioner’s evidence, Patent Owner’s
`Response and its evidence and have determined that the record supports that
`both Akasaki and Sonobe disclose the dry etching and wet etching of a GaN
`epitaxial layer as claimed in claims 1, 11, and 13 of the ’475 patent.
`Therefore, the only issue before us is whether or not either Akasaki or
`Sonobe disclose “crystallographic etching”5 as we have construed the terms.
`2. Anticipation by Akasaki
`Petitioner contends that claims 1, 2, 4, 11–14, and 16 of the ’475
`Patent are anticipated under 35 U.S.C. § 102(a) by Akasaki. Pet. 18–25. To
`support this position, Petitioner presents the Wetzel Declaration. Ex. 1003
`¶¶ 72–76. In light of the arguments and evidence submitted by both parties,
`for the reasons discussed below, Petitioner has not shown by a
`preponderance of the evidence that claims 1, 2, 4, 11–14, and 16 of the ’475
`patent are anticipated by Akasaki.
`a. Akasaki Overview
`Akasaki is directed to a method of manufacturing a group III nitride
`semiconductor. Ex. 1006, Title. According to Akasaki, there were “known
`blue light-emitting diodes (LEDs) and blue laser diodes (LDs), formed from
`individual layers made of a gallium nitride compound semiconductor
`(AlGaInN) on a sapphire substrate.” Id. ¶ 2.
`
`
`5 Hereafter we will refer to “crystallographic etching” understanding that
`“crystallographically etching” is encompassed by that reference.
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`In an embodiment of Akasaki, “a p layer and a n layer are formed
`from a group III nitride semiconductor on the substrate, where the individual
`layers are formed from group III nitride semiconductors on the substrate.”
`Id. ¶ 4. Each layer is dry-etched in order to form end faces of a resonator.
`Id. After dry etching, the end faces that have been dry-etched are wet-etched
`through an etching solution. Id. The result of the wet etching is that the
`damage caused to the end faces of the resonator by dry etching is removed,
`improving the degree of mirror surfacing of the end faces. Id.
`Figure 2 of Akasaki is reproduced below:
`
`
`Figure 2 illustrates the first manufacturing step of the method of the
`present invention. Substrate 1 is sapphire. Id. ¶ 7. Individual layers are
`formed sequentially on substrate 1. Id. ¶ 8. An n conductivity-type clad
`layer 4 is made from aluminum gallium nitride (Al0.08Ga0.92N). Id. ¶ 11.
`Layer 5 is an active layer of Al0.08Ga0.92N. Id. ¶ 12. Layer 61 is a p
`conductivity-type clad layer of magnesium-doped Al0.08Ga0.92N. Id. ¶ 13.
`Contact layer 62 is formed from magnesium doped GaN. Id. ¶ 14.
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`Figure 7 of Akasaki is reproduced below:
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`FIG. 7 is a perspective cross section of a structure for a laser diode
`after the dry etching and wet etching steps. Resonator end faces S, with
`“high levels of squareness relative to the substrate 1 and with high levels of
`parallel between the end faces were obtained in the active layer 5.” Ex.
`1006 ¶ 21.
`
`b. Whether Akasaki Discloses “crystallographic etching”
`All three independent claims recite either “crystallographic etching”
`or “crystallographically etching.” Akasaki discloses performing “wet
`etching of the end faces that had been dry-etched.” Ex. 1006 ¶ 0021.
`Relying on Dr. Wetzel’s Declaration, Petitioner alleges that the wet etching
`of Akasaki is “crystallographic,” as recited in claim 1. Pet. 20 (citing Ex.
`1003 ¶¶ 74–75).
`Akasaki further specifies the result obtained by wet etching is a
`resonator end face S with “high levels of squareness” and “high levels of
`parallel between the end faces.” Ex. 1006 ¶ 21; see Fig. 7. The wet etching
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`results in “improving the degree of mirror surfacing.” Id. ¶ 5, Fig. 1.
`Petitioner cites to the preceding language regarding wet etching as additional
`support for contending Akasaki discloses “crystallographically etching” the
`epitaxial layer system. Pet. 20–21.
`Patent Owner argues neither Akasaki nor Sonobe discloses
`“crystallographic etching.” PO Resp. 3, 23–30. Patent Owner further notes
`that neither reference mentions “crystallographic etching” nor identifies any
`specific crystal plane. Id. Thus, Patent Owner contends there is no express
`disclosure of “crystallographic etching.” Id. at 4, 23–30. Patent Owner also
`argues there is no inherent disclosure of the limitation. Id. at 4, 30–60.
`In illustrating its primary argument, that defect etching shown in
`Akasaki and Sonobe is not “crystallographic etching,” Patent Owner labels
`the GaN epitaxial layer of the etched material as layer B. PO Resp. 4–5.
`Conversely, layer A is denominated as the layer of damage and
`contamination left after the dry etch. Id. Patent Owner cites to the
`Declaration of Professor James R. Shealy (“Shealy Declaration,” Ex. 2014)
`as evidence that reactive ion beam etching is known to create a layer of
`amorphous damage, i.e., Material A. Id. at 5–6, see Ex. 2014 ¶ 79.
`Patent Owner argues the ’475 patent distinguishes between defect
`etching and crystallographic etching. PO Resp. 17. Specifically, Patent
`Owner states defect etching is known to etch pits at defect sites. Id. (citing
`Ex. 1001, 3:33–35). By contrast, the ’475 patent discloses that “non-c
`planes can be crystallographically etched by molten KOH.” Id. (citing Ex.
`1001, 3:18–21). As a result, Patent Owner contends one of ordinary skill in
`the art would distinguish crystallographic etching from defect-revealing
`etching. Id. (citing Ex. 2014 ¶ 36).
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`As to Akasaki specifically, Patent Owner notes that the dry etching
`step produces defects “due to the end faces being damaged by the ions.” PO
`Resp. 24 (citing Ex. 1006 ¶ 3). The damage is removed by wet etching,
`“thus improving the degree of mirror surfacing of the end faces.” Id. (citing
`Ex. 1006 ¶ 5). Patent Owner concludes that Akasaki does nothing through
`the wet etching step other than remove damage. Id. at 26. Patent Owner
`cites to Dr. Shealy for his conclusion that the “high levels of squareness
`relative to the substrate” and the “high levels of parallel between the end
`faces” in Akasaki were produced by the vertical dry etching. Id. (citing Ex.
`2014 ¶¶ 53–55). Thus Patent Owner argues Akasaki does not expressly
`disclose “crystallographically etching.” Id.
`Patent Owner makes several additional arguments that neither
`Akasaki nor Sonobe expressly or inherently disclose “crystallographic
`etching.” PO Resp. 30–60. The arguments include: neither discloses
`aligning the mask with an appropriate crystal plane (PO Resp. 31–38);
`etching damage and contaminants is not “crystallographic etching” (PO
`Resp. 38–44); no etching beyond the defect layer is disclosed (PO Resp. 44–
`45); there is insufficient information on reagents or conditions to conclude
`“crystallographic etching” takes place (PO Resp. 46–47); “crystallographic
`etching” cannot be inferred from Akasaki’s laser performance data (PO
`Resp. 47–54); Akasaki’s and Sonobe’s drawings are not evidence of
`“crystallographic etching” (PO Resp. 54–56); and descriptions of etching
`results are not evidence of “crystallographic etching” (PO Resp. 56–59).
`In its Reply, Petitioner argues Figure 2 of the ’475 patent, which
`shows defect pits, discloses etching that proceeds in directions dictated by
`the crystallographic planes of GaN. Pet. Reply 2. Petitioner notes that the
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`discovery of the ’475 patent is that etching proceeds in directions dictated by
`the crystallographic planes, i.e., crystallographic etching. Id.
`Petitioner concludes that the “broadest reasonable construction of
`‘crystallographic etching’ must include the Figure 2 embodiment.” Id. at 3.
`Petitioner notes that other references of record disclose etch pits in GaN that
`are “hexagonal pyramids, which reflect the crystal symmetry of GaN.” Pet.
`Reply 4 (citing Ex. 1011, Abstract). Further, this prior art disclosure,
`according to Petitioner, identifies the non-c-plane crystal facets of the
`pyramids. Id. (citing Reply Declaration of Dr. Christian M. Wetzel, “Wetzel
`Reply Declaration,” Ex. 1041 ¶¶ 17–18).
`Petitioner relies on Akasaki and Sonobe as expressly, or at a minimum
`inherently, disclosing “crystallographic etching.” Tr. 55:14–16. However,
`neither the Petition nor any evidence provided in its Reply identifies any
`basis for concluding that “crystallographic etching” is expressly disclosed.
`Indeed, Dr. Wetzel does not state any facts that support a conclusion that the
`references etch the gallium nitride layer, the so called B layer. See Ex. 1041,
`160–180.
`We are not persuaded that Figure 2 of the ’475 patent discloses an
`“embodiment” that includes defect etching as “crystallographic etching,” as
`we have construed that term above in section II.A.5. The ’475 patent does
`differentiate defect etching from “crystallographic etching.” See Ex. 1001,
`3:17–31. For example the ’475 patent acknowledges that “[M]olten KOH is
`known to form pits at dislocations in the c-plane of GaN.” Id. at 3:18–19.
`Further, exposing a defect pit that has planar surfaces by wet etching is not
`“etching that proceeds in directions dictated by the crystallographic planes
`of the material being etched.” Dec. Inst. 11–12.
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`Petitioner points to Figure 2 as showing that the faces produced in the
`defect pits are “two or more competing etch planes.” Pet. Reply 2–3 (citing
`Ex. 1001, 3:40–44; see also Ex. 1041 ¶¶ 7–9). However, this disclosure
`does not support the position that Figure 2 is an example of
`“crystallographic etching.” “Crystallographic etching” is directed to
`creating a “crystallographic plane surface” (see claim 1) and not multiple
`“competing etch planes.” Dr. Shealy also testifies that Figure 2 shows
`“many, many crystal planes” and is not “crystallographic etching.”
`Deposition of James R. Shealy, Ex. 1040, 48:13–22. Dr. Wetzel’s Reply
`Declaration does not dictate a different result. Ex. 1041 ¶¶ 7–9.
`As discussed above, Petitioner argues Akasaki expressly, or at least
`inherently, discloses “crystallographic etching.” Petitioner argues the
`smooth mirror faces which result from the wet etching in Akasaki are
`evidence that “crystallographic etching” necessarily results. Tr. 59:14–18;
`see Ex. 1006 ¶ 4. However, Akasaki states clearly that the wet etch step
`removes damage caused by the dry etch, “thus improving the degree of
`mirror surfacing of the end faces.” Ex. 1006 ¶ 5. Smooth surfaces alone do
`not necessarily imply “crystallographic etching” because the smooth surface
`may result from only the removal of damage caused by the dry etch.
`Petitioner has produced no evidence that would lead us to conclude
`that the wet etch in Akasaki goes beyond the damage produced by the dry
`etch—i.e., the amorphous layer (Patent Owner’s Layer A)—to actually etch
`the epitaxial layer system (Patent Owner’s Layer B). “Crystallographic
`etching” might possibly then occur, but Petitioner has not shown that it
`necessarily occurs.
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`c. Summary of Akasaki
`Petitioner has not shown by a preponderance of the evidence that
`Akasaki expressly or inherently discloses “crystallographic etching.”
`Independent claims 1, 11, and 13 all recite “crystallographic etching” or
`“crystallographically etching.” The remaining dependent claims 2, 4, 12, 14,
`and 16 necessarily require the limitation. Petitioner has failed to show by a
`preponderance of the evidence that claims 1, 2, 4, 11–14, and 16 of the ’475
`patent are anticipated by Akasaki.
`2. Anticipation by Sonobe
`Petitioner contends that claims 1, 2, 4, 11–14, and 16 of the ’475
`Patent are anticipated under 35 U.S.C. § 102(b) by Sonobe. Pet. 25–31. To
`support this position, Petitioner relies, in part, on the testimony of Dr.
`Wetzel. Ex. 1003 ¶¶ 77–80. In light of the arguments and evidence
`submitted by both parties, for the reasons discussed below, Petitioner has not
`shown by a preponderance of the evidence that claims 1, 2, 4, 11–14, and 16
`of the ’475 patent are anticipated by Sonobe.
`a. Sonobe Overview
`Sonobe discloses a “Method of Manufacturing Semiconductor Light-
`Emitting Element.” Ex. 1009, Title. Sonobe’s method is directed to etching
`of a gallium nitride group semiconductor layer by first dry etching the
`semiconductor layer and then carrying out wet etching. Id. at Abstract. The
`result of the method is a light emitting-diode which is etched vertically so
`that light is emitted from the side surface exposed by etching. Id. ¶¶ 1, 3.
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`Figure 2(d) is reproduced below.
`
`
`Figure 2(d) is a cross section of the laminate layers of the
`semiconductor during one step of the manufacturing process. As shown in
`Figure 2(d), the laminate layers include substrate 1, low temperature buffer
`layer 2, high temperature buffer layer 3, n-type cladded layer 4, activated
`layer 5, p-type cladded layer 6, and cap layer 7. Ex. 1009 ¶ 21. Dry etching
`of the laminated semiconductor layers using reactive ion etching is
`performed. Id. ¶ 24. Wet etching is performed using an etching solution.
`Id. As a result, the etched surface is not damaged, and the perpendicularity
`of the lateral surface of the semiconductor, which had been etched relative to
`the surface of the semiconductor layer, is maintained as indicated in Figure
`2(d). Id.
`
`b. Whether Sonobe Discloses “crystallographic etching”
`Sonobe discloses that, after dry etching, wet etching is performed.
`Ex. 1009 ¶ 16. Petitioner argues this portion of Sonobe6 meets the
`“crystallographically etching” limitation of claim 1 and forms
`crystallographic plane surfaces. Pet. 27 (citing Ex. 1003 ¶¶ 79–80). Sonobe
`also discloses perpendicular lateral semiconductor surfaces, which Petitioner
`
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`6 Petitioner mistakenly cites to Ex. 1010 (Certification of the Translation of
`Sonobe) instead of Ex. 1009 (Sonobe Translation).
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`interprets as “crystallographic plane surfaces” from wet etching. Pet. 27
`(citing Ex. 1009 ¶¶ 24, 31).
`Patent Owner’s arguments described above in the discussion of
`Akasaki apply generally to both Akasaki and Sonobe. Specific to Sonobe,
`Patent Owner contends Sonobe does not purport to disclose crystallographic
`etching at all, but instead discloses using the wet etch to “clean” the surface
`after dry etching. PO Resp. 5, 27–30; see Ex. 1009 ¶¶ 11, 15.
`Further, Patent Owner offers evidence that “crystallographic etching”
`proceeds at different rates depending on the particular plane involved. Id. at
`6 (citing Ex. 2014 ¶ 60). Etching at different rates for different
`crystallographic planes is anisotropic. Id. (citing Ex. 2014 ¶ 60). Etching
`that proceeds equally in all directions is called isotropic etching. Id. (citing
`Ex. 2014 ¶ 60). Patent Owner’s expert concludes that Sonobe describes
`isotropic etching based, in part on descriptions of a “round part.” Id.
`(citing Ex. 2014 ¶ 60).
`Patent Owner further notes that the “perpendicularity of the lateral
`surface of the semiconductor” is created by Sonobe in the first instance by
`dry etching and “is maintained” after wet etching. PO Resp. 27 (citing Ex.
`1009 ¶ 24). Patent Owner argues that Sonobe describes dry etching as
`resulting in “approximately 90 to 95% of the entire etching amount.” Id. at
`27 (citing Ex. 1009 ¶ 25).
`Petitioner’s arguments in response include those made in regard to
`Akasaki. As to Sonobe specifically, Petitioner argues that the etching that is
`“carried out evenly” on the sidewalls to maintain “[t]he perpendicularity of
`the lateral surface” is “crystallographic etching.” Pet. Reply 11 (citing Ex.
`1009 ¶ 24; see also Ex. 1041 ¶ 46).
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