`Filed By: Donald R. Steinberg, Reg. No. 37,241
`David L. Cavanaugh, Reg. No. 36,476
`Michael H. Smith, Reg. No. 71,190
`60 State Street
`Boston, Massachusetts 02109
`Tel: (617) 526-6000
`Email: Don.Steinberg@wilmerhale.com
`
` David.Cavanaugh@wilmerhale.com
`
` MichaelH.Smith@wilmerhale.com
`
`
`
`
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`____________________________________________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`____________________________________________
`
`
`
`
`
`ASML Netherlands B.V., ASML U.S., Inc., Excelitas Technologies Corp., and
`Qioptiq Photonics GmbH & Co. KG,
`Petitioners
`
`v.
`
`Energetiq Technology, Inc.,
`Patent Owner.
`
`Case IPR2016-00775
`
`
`
`PETITION FOR INTER PARTES REVIEW OF
`U.S. PATENT NO. 9,048,000
`CLAIMS 16, 17
`
`
`
`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`TABLE OF CONTENTS
`
`Page
`
`I.
`
`MANDATORY NOTICES ............................................................................. 1
`A.
`Real Parties-in-Interest .......................................................................... 1
`B.
`Related Matters ...................................................................................... 1
`C.
`Counsel .................................................................................................. 2
`D.
`Service Information ............................................................................... 2
`CERTIFICATION OF GROUNDS FOR STANDING .................................. 3
`II.
`III. OVERVIEW OF CHALLENGE AND RELIEF REQUESTED .................... 3
`A. Grounds for Challenge .......................................................................... 3
`B.
`Prior Art Patents and Printed Publications Relied Upon ...................... 3
`C.
`Relief Requested .................................................................................... 4
`IV. PERSON OF ORDINARY SKILL IN THE ART .......................................... 4
`V. OVERVIEW OF THE ’000 PATENT ............................................................ 5
`A.
`Summary of the Prosecution History .................................................... 7
`VI. CLAIM CONSTRUCTION ............................................................................ 9
`A.
`“light” .................................................................................................. 11
`VII. THE CHALLENGED CLAIMS ARE UNPATENTABLE .......................... 13
`A.
`Laser Sustained Plasma Light Sources Were Known Long
`Before the Priority Date of the ’000 Patent ......................................... 13
`High pressure plasma light sources were well-known in the art. ....... 14
`Sustaining a plasma with a laser at various wavelengths,
`including those up to about 2000 nm, was well known in the art ....... 14
`VIII. GROUNDS FOR FINDING THE CHALLENGED CLAIMS INVALID ... 24
`A. Ground 1: Claims 16 and 17 Are Unpatentable Over Gärtner in
`View of Mourou and Silfvast .............................................................. 24
`1. Claim 15 ....................................................................................... 25
`2. Claim 15 – Reasons to Combine .................................................. 36
`3. Claim 16 ....................................................................................... 41
`4. Claim 17 ....................................................................................... 44
`
`B.
`C.
`
`i
`
`
`
`B.
`
`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`5. Claims 16 and 17 – Reasons to Combine ..................................... 46
`Ground 2: Claims 16 and 17 Are Unpatentable Over Gärtner in
`View of Kensuke and Silfvast ............................................................. 46
`1. Claim 15 ....................................................................................... 47
`2. Claim 15 – Reasons to Combine .................................................. 52
`3. Claim 16 ....................................................................................... 54
`4. Claim 17 ....................................................................................... 55
`5. Claims 16 and 17 – Reasons to Combine ..................................... 55
`IX. RESPONSE TO ARGUMENTS RAISED BY PATENT OWNER
`REGARDING OBJECTIVE INDICIA OF NON-OBVIOUSNESS ............ 55
`CONCLUSION .............................................................................................. 57
`
`X.
`
`ii
`
`
`
`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`
`I. MANDATORY NOTICES
`A. Real Parties-in-Interest
`ASML Netherlands B.V., ASML U.S., Inc., Excelitas Technologies Corp.,
`
`and Qioptiq Photonics GmbH & Co. KG (“Petitioners”) are the real parties-in-
`
`interest.
`
`B. Related Matters
`U.S. Patent No. 9,048,000 (the “’000 patent,” Ex. 1301) is one member of a
`
`patent family of continuation and continuation-in-part (CIP) applications. Exhibit
`
`1302 shows the members of this patent family and the relationships among them.
`
`Petitioners already filed a petition seeking inter partes review of claims 1, 15, and
`
`18 of the ’000 patent, which the Board instituted on November 30, 2015 on all
`
`challenged claims. (See Case No. IPR2015-01375 (PTAB Nov. 30, 2015) (Paper
`
`13).) Petitioners also filed a petition seeking inter partes review of claims 7-10 of
`
`the ’000 patent, which is currently pending. (See Case No. IPR2016-00126 (PTAB
`
`Nov. 4, 2015) (Paper 4).) Petitioners are also seeking inter partes review of related
`
`U.S. Patent Nos. 7,435,982 (“the ’982 patent”); 7,786,455 (“the ’455 patent”);
`
`8,309,943 (“the ’943 patent”); 8,525,138 (“the ’138 patent”); and 8,969,841 (“the
`
`’841 patent”) in Case Nos. IPR2015-01300, IPR2015-01303, IPR2015-01377,
`
`IPR2016-00583, IPR2016-00584, IPR2016-00585, IPR2015-01279, IPR2016-
`
`00570, IPR2016-00575, IPR2016-00576, IPR2016-00578, IPR2016-00579,
`
`1
`
`
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`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`IPR2015-01277, IPR2016-00554, IPR2016-00556, IPR2016-00555, IPR2015-
`
`01368, IPR2016-00565, IPR2016-00566, IPR2015-01362, and IPR2016-00127.
`
`The status of the other proceedings is summarized in Exhibit 1326.
`
`Petitioners are also filing additional petitions on the ’841 and ’000 patents,
`
`as well as on related U.S. Patent No. 9,185,786 (“the ’786 patent”). Petitioners
`
`request that all these inter partes reviews be assigned to the same Panel for
`
`administrative efficiency.
`
`The following litigation matters would affect or be affected by a decision in
`
`this proceeding: Energetiq Tech., Inc. v. ASML Netherlands B.V., No. 1:15-cv-
`
`10240-LTS (D. Mass.) and In the Matter of Certain Laser-Driven Light Sources,
`
`Subsystems Containing Laser-Driven Light Sources, and Products Containing
`
`Same, Inv. 337-TA-983 (U.S. International Trade Commission).
`
`C. Counsel
`Lead Counsel: Donald R. Steinberg (Registration No. 37,241)
`
`Backup Counsel: David L. Cavanaugh (Registration No. 36,476)
`
`Second Backup Counsel: Michael H. Smith (Registration No. 71,190)
`
`Service Information
`
`D.
`Email: Donald R. Steinberg, don.steinberg@wilmerhale.com
`
`Post and Hand Delivery: WilmerHale, 60 State St., Boston MA 02109
`
`Telephone: 617-526-6453
`
`
`
`Facsimile: 617-526-5000
`
`2
`
`
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`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`Petitioners consent to service by email on lead and backup counsel.
`
`II. CERTIFICATION OF GROUNDS FOR STANDING
`Petitioners certify pursuant to Rule 42.104(a) that the patent for which
`
`review is sought is available for inter partes review and that Petitioners are not
`
`barred or estopped from requesting an inter partes review challenging the patent
`
`claims on the grounds identified in this Petition.
`
`III. OVERVIEW OF CHALLENGE AND RELIEF REQUESTED
`Pursuant to Rules 42.22(a)(1) and 42.104 (b)(1)-(2), Petitioners challenge
`
`claims 16 and 17 of the ’000 patent (“the challenged claims”) and request that each
`
`challenged claim be cancelled.
`
`A. Grounds for Challenge
`This Petition, supported by the declaration of Dr. J. Gary Eden, a Professor
`
`of Electrical Engineering at the University of Illinois (“Eden Decl.,” Ex. 1303),
`
`demonstrates that there is a reasonable likelihood that Petitioners will prevail with
`
`respect to at least one of the challenged claims and that each of the challenged
`
`claims is unpatentable for the reasons cited in this petition. 35 U.S.C. § 314(a).
`
`Prior Art Patents and Printed Publications Relied Upon
`
`B.
`Petitioners rely upon the following patents and printed publications:
`
`1. French Patent Publication No. FR2554302A1, published May 3, 1985, with
`
`English Translation (“Gärtner,” Ex. 1304), which is prior art to the ’000 patent
`
`under 35 U.S.C. § 102(b).
`
`3
`
`
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`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`2. International Publication WO-2004097520, published November 11, 2004
`
`(“Mourou,” Ex. 1305), which is prior art to the ’000 patent under 35 U.S.C. §
`
`102(b).
`
`3. William T. Silfvast, Laser Fundamentals, (2d ed.), published in 2004
`
`(“Silfvast,” Ex. 1309), which is prior art to the ’000 patent under 35 U.S.C. §
`
`102(b).
`
`4. Japanese Patent Pub. No. 2006010675A, filed on February 24, 2005 and
`
`published January 12, 2006, with English Translation (“Kensuke,” Ex. 1306),
`
`which is prior art to the ’000 patent under 35 U.S.C. § 102(a) and (b).
`
`C. Relief Requested
`Petitioners request that the Patent Trial and Appeal Board cancel the
`
`challenged claims because they are unpatentable under at least 35 U.S.C. § 103.
`
`IV. PERSON OF ORDINARY SKILL IN THE ART
`A person of ordinary skill in the art at the time of the alleged invention of
`
`the ’000 patent would have had a Ph.D. in physics, electrical engineering, or an
`
`equivalent field and 2-4 years of work experience with lasers and plasmas, or a
`
`master’s degree in physics, electrical engineering, or an equivalent field and 4-5
`
`years of work experience with lasers and plasmas. (Eden Decl. at ¶ 25 (Ex. 1303).)
`
`The ’000 patent is entitled “High Brightness Laser-Driven Light Source.”
`
`The patent states that the alleged “invention relates to methods and apparatus for
`
`4
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`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`providing a laser-driven light source.” (’000 patent at 1:20-24 (Ex. 1301).) The
`
`laser maintains a plasma. Accordingly, the problem and solution are directly tied
`
`to lasers and plasmas and a person of ordinary skill would be expected to have
`
`experience in both of these areas. (Eden Decl. at ¶ 26 (Ex. 1303).)
`
`Consistent with this, Dr. Eden’s graduate students in 2005 (as well as before
`
`that time and since) normally took graduate level courses in both lasers and plasma
`
`physics, and routinely worked with plasmas, many of which were produced with
`
`lasers. Lasers sufficiently powerful to generate and/or sustain a plasma are a
`
`potential safety hazard, and safety concerns require those working with laser-
`
`sustained plasmas to both understand and acquire experience working with such
`
`lasers. By the time Dr. Eden’s graduate students obtained their Ph.D. degrees, they
`
`would have had at least 4-5 years of experience with both plasmas and lasers.
`
`Thus, the problem and solution to which the ’000 patent is directed, and the
`
`experience of those who typically would work on developing laser-generated
`
`plasmas demonstrate that a person of ordinary skill would have the above
`
`experience with lasers and plasmas. (Eden Decl. at ¶ 27 (Ex. 1303).)
`
`V. OVERVIEW OF THE ’000 PATENT
`The ’000 patent family is directed to a laser sustained plasma light source for
`
`use in, for example, testing and inspection for semiconductor manufacturing. As
`
`depicted in Figure 1, shown below, the light source includes a pressurized chamber
`
`5
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`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`(green) containing gas, an ignition source (blue) for ionizing a gas, and a laser
`
`(red) for providing energy to the plasma (yellow) to produce light. (’000 patent,
`
`claim 1 (Ex. 1301).) The ’000 continuation adds claims that require a pressurized
`
`chamber, the plasma-generated light having wavelengths greater than 50 nm, and
`
`providing laser energy having a wavelength range of up to about 2000 nm. (Eden
`
`Decl. at ¶ 28 (Ex. 1303).)
`
`
`
`’000 Patent, Fig. 1 (Annotated) (Ex. 1301)
`
`As discussed below, there was nothing new in 2006 about generating or
`
`sustaining a plasma with a laser to produce light. Multiple prior art references,
`
`including Gärtner, Mourou, and Kensuke, disclosed laser-sustained plasma light
`
`sources. Moreover, there was nothing new about providing energy to a plasma
`
`with a laser having a wavelength in the range of up to about 2000 nm. As the
`
`patent admits, efficient, cost effective, and high power lasers in the claimed
`
`wavelength range were “recently available.” (’000 patent at 16:6-7 (Ex. 1301)
`
`6
`
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`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`(emphasis added).) Gärtner provides an example of a system that maintains a
`
`plasma, and Mourou and Kensuke provide examples of systems that provide
`
`energy to a plasma with a laser operating within the claimed wavelength range.
`
`Silfvast shows that the use of titanium-doped sapphire (Ti:sapphire) lasers, such as
`
`those disclosed by Mourou and Kensuke, were among the most widely used
`
`tunable solid-state laser. It would have been obvious to combine Mourou and
`
`Silfvast or Kensuke and Silfvast with Gärtner to arrive at the claimed invention.
`
`(Eden Decl. at ¶ 29 (Ex. 1303).)
`
`A.
`
`Summary of the Prosecution History
`
`The ’000 patent issued from U.S. Patent Application No. 13/964,938, which
`
`was filed on August 12, 2013. The ’000 patent is a continuation of the ’138 patent,
`
`which is a CIP of the ’786 patent, which is a CIP of the ’455 patent, which is a CIP
`
`of the ’982 patent, filed March 31, 2006. (See Chart of Related Patents (Ex.
`
`1302).) During prosecution, the Examiner repeatedly rejected the pending claims
`
`and Applicant’s arguments that features such as a “pressurized chamber”
`
`distinguished over the prior art. (See, e.g., Office Action dated July 17, 2014 at 2-3
`
`(Ex. 1310).)
`
`On January 6, 2015, the applicant further amended some, but not all, of the
`
`claims to require a laser having a wavelength “of up to about 2000 nm.”
`
`(Applicant’s Amendment and Response dated Jan. 6, 2015 at 2-6 (Ex. 1311).)
`
`7
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`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`On February 27, 2015, the Examiner indicated that claims reciting “at least
`
`one substantially continuous laser for providing energy within a wavelength in the
`
`range of about 700 nm to 2000 nm to an ionized gas to sustain a plasma within a
`
`chamber having greater than atmospheric pressure to produce a plasma-generated
`
`light having wavelengths greater than 50 nm” contained allowable subject matter.1
`
`(Office Action dated Feb. 27, 2015 at 7 (Ex. 1312).)
`
`On March 25, 2015, the amended claims were allowed after the applicant
`
`filed a terminal disclaimer and amended the claims to overcome a section 112
`
`rejection. (Notice of Allowability dated Mar. 25, 2015 (Ex. 1316); Applicant’s
`
`Amendment and Response dated Mar. 5, 2015 (Ex. 1317).) The Examiner noted
`
`that, “[r]egarding dependent claims 2-4, 8, 9, 14-20, 27-28, and 31, 33-39; these
`
`claims are allowable at least for their dependence, either directly or indirectly upon
`
`independent claims 1, 13, 26, and 32.” (Notice of Allowability dated Mar. 25,
`
`2015 at 4 (Ex. 1316).)
`
`The prosecution history of the ’000 patent provides no indication that the
`
`examiner appreciated the significance of Gärtner (submitted on March 11, 2015,
`
`several weeks after the Examiner had indicated the claims recite allowable subject
`
`1 Unlike independent claim 1, independent claim 15 of the ’000 patent, from which
`
`the challenge claims depend, does not recite “substantially continuous” laser
`
`energy.
`
`8
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`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`matter). (See Information Disclosure Statement dated March 11, 2015 (Ex. 1319).)
`
`The Examiner also failed to consider Mourou and Silfvast. Neither was the
`
`Examiner provided with a complete English translation of Kensuke.2
`
`As discussed below, Gärtner in view of Mourou and Silfvast, and Gärtner in
`
`view of Kensuke and Silfvast, each render the challenged claims unpatentable as
`
`obvious. The claimed features are present in the prior art used in the proposed
`
`grounds of unpatentability, as the Board recognized in its Decision on Institution in
`
`an IPR directed to the same patent. (Case No. IPR2015-01375 at 20-21 (PTAB
`
`Nov. 30, 2015) (Paper 13) (instituting on claims including independent claim 15).)
`
`VI. CLAIM CONSTRUCTION
`A claim in inter partes review is given the “broadest reasonable construction
`
`in light of the specification.” 37 C.F.R. § 42.100(b). Any claim term which lacks
`
`2 Kensuke (JP 2006-10675) was included in an Information Disclosure Statement
`
`filed by Applicant on March 11, 2014. (See Information Disclosure Statement
`
`submitted on March 11, 2014 (Ex. 1322).) However, Applicant only submitted an
`
`English translation for the abstract and Kensuke was not used in any of the
`
`Examiner’s rejections. Notably, as described further below, Kensuke discloses the
`
`use of a laser with a wavelength range of up to about 2000 nm to create a plasma
`
`that produced a light with a wavelength greater than 50 nm, but the abstract does
`
`not provide this disclosure (see infra).
`
`9
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`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`a definition in the specification is also given a broad interpretation. In re ICON
`
`Health & Fitness, Inc., 496 F.3d 1374, 1379 (Fed. Cir. 2007).
`
`Should the Patent Owner, seeking to avoid the prior art, contend that the
`
`claims have a construction different from their broadest reasonable construction,
`
`the appropriate course is for the Patent Owner to seek to amend the claims to
`
`expressly correspond to its contentions in this proceeding. See 77 Fed. Reg.
`
`48,756, 48,766-67 (Aug. 14, 2012).
`
`Consistent with this standard, this section proposes, under the broadest
`
`reasonable construction standard, constructions of terms and provides support for
`
`these proposed constructions. Terms not included in this section have their
`
`broadest reasonable meaning in light of the specification as commonly understood
`
`by those of ordinary skill.
`
`Applying the claim construction standard of Phillips v. AWH Corp., 415
`
`F.3d 1303 (Fed. Cir. 2005) would not change the analysis or conclusions covered
`
`in this petition. The prior art teaches each claim limitation under any reasonable
`
`interpretation of the claim terms, and the analysis is not dependent on application
`
`of the “broadest reasonable interpretation” standard. (See Eden Decl. at ¶ 36 (Ex.
`
`1303).)
`
`10
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`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`
`“light”
`
`A.
`The term “light” is recited in claim 15, from which challenged claims 16 and
`
`17 depend. “Light” should be construed to mean “electromagnetic radiation in the
`
`ultraviolet (“UV”), extreme UV, vacuum UV, visible, near infrared, middle
`
`infrared, or far infrared regions of the spectrum, having wavelengths within the
`
`range of 10 nm to 1,000 µm,” as the Board construed the term in its Decision on
`
`Institution in an IPR directed to the ’000 patent. (Case No. IPR2015-01375 at 6
`
`(PTAB Nov. 30, 2015) (Paper 13).) (Eden Decl. at ¶ 37 (Ex. 1303).) This
`
`construction is equivalent to the Petitioners’ proposed construction for the term
`
`“light” in that proceeding.
`
`The ordinary and customary meaning of “light”3 is electromagnetic radiation
`
`in the extreme ultraviolet (EUV) (10 nm to 100 nm), vacuum ultraviolet (100 nm
`
`to 200 nm), ultraviolet (200 nm to 400 nm), visible (400 to 700 nm), near-infrared
`
`3 The term “light” is sometimes used more narrowly to refer only to visible light.
`
`However, references to “ultraviolet light” in the ’000 patent make clear that the
`
`broader meaning is intended because ultraviolet light has a wavelength shorter than
`
`that of visible light. (See, e.g., ’000 patent at 1:51-54, 7:49-51, 12:25-29, 15:6-9,
`
`16:46-52, 16:65-67, 17:12-14, 18:34-36, 18:42-44, 19:8-10, 19:51-55, 20:26-35,
`
`21:15-20, 22:5-8, 23:28-29, 25:60-64, 26:32-36, 27:21-24, 31:41-46, 32:32-34,
`
`33:17-19, 45:20-35 (Ex. 1301).) (See Eden Decl. at ¶ 38 n.2 (Ex. 1303).)
`
`11
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`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`(700 nm to 1,000 nm (1 µm)), middle infrared (1 µm to 10 µm), or far infrared (10
`
`µm to 1,000 µm) regions of the spectrum. (See, e.g., Silfvast at 4 (2 Ed., 2004))
`
`(Ex. 1309).) The Patent Owner publishes a data sheet which is consistent with the
`
`ordinary and customary meaning in recognizing that “light source” includes EUV
`
`wavelengths. (See, e.g., Energetiq EQ-10M Data Sheet at 2 (describing
`
`Energetiq’s EQ-10M product operating at 13.5 nm as an “EUV Light Source”)
`
`(Ex. 1308).) (Eden Decl. at ¶ 38 (Ex. 1303).)
`
`The ’000 patent does not provide a definition of the term “light” and uses the
`
`term consistent with the ordinary and customary meaning of the term. Consistent
`
`with the ordinary and customary meaning of “light,” the ’000 patent states that
`
`parameters such as the wavelength of the light from a light source “vary depending
`
`upon the application.” (’000 patent at 1:35-37 (Ex. 1301).) The specification
`
`describes “ultraviolet light” as an example of the type of light that can be
`
`generated. (See, e.g., ’000 patent at 18:34-36 (Ex. 1301); see also id. at 17:12-14
`
`(Ex. 1301).) (Eden Decl. at ¶ 39 (Ex. 1303).)
`
`Therefore, the term “light” should be construed to mean “electromagnetic
`
`radiation in the ultraviolet (“UV”), extreme UV, vacuum UV, visible, near
`
`infrared, middle infrared, or far infrared regions of the spectrum, having
`
`wavelengths within the range of 10 nm to 1,000 µm.” (Eden Decl. at ¶ 40 (Ex.
`
`1303).)
`
`12
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`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`VII. THE CHALLENGED CLAIMS ARE UNPATENTABLE
`Challenged claims 16 and 17 recite and claim features that were known in
`
`the art prior to the earliest priority date of the ’000 patent, and are obvious in view
`
`of the prior art.
`
`A. Laser Sustained Plasma Light Sources Were Known Long Before
`the Priority Date of the ’000 Patent
`
`When the application that led to the ’000 patent was filed, there was nothing
`
`new or inventive about a light source ionizing a gas in a pressurized chamber and a
`
`laser operating at certain wavelengths to generate or sustain a plasma in a
`
`pressurized chamber to produce light at certain wavelengths. This concept had
`
`been known and widely used since at least as early as the 1980s, more than two
`
`decades before the application date. (Eden Decl. at ¶ 42 (Ex. 1303).)
`
`For example, Gärtner, which published in 1985, discloses a light source with
`
`the same features claimed in the ’000 patent: (1) a pressurized chamber 1 (green);
`
`(2) an ignition source – pulsed laser 10 (blue); (3) a laser 9 (red), which provides
`
`energy to the plasma 14 (yellow) and produces light 15 having a wavelength
`
`greater than 50 nm; and (4) a transparent region of the chamber that allows the
`
`produced light to exit the chamber. (Gärtner at 4:31-5:9, Fig. 1 (Ex. 1304).) (Eden
`
`Decl. at ¶ 43 (Ex. 1303).)
`
`13
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`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`
`
`
`
`
`’000 patent at Fig. 1 (Ex. 1301)
`
`
`
`Gärtner at Fig. 1 (Ex. 1304)
`
`B. High pressure plasma light sources were well-known in the art.
`Plasma light sources with operating pressures of greater than 10 atmospheres
`
`(atm) (as recited in claim 15 from which claims 16 and 17 depend) were also well-
`
`known in the art. As discussed below, Gärtner teaches pressures of greater than 10
`
`atm. Also, a 1989 textbook notes that “[l]aser-sustained plasmas have been
`
`operated in a variety of molecular and rare gases at pressures from 1 to more than
`
`200 atm.” (D. Keefer, “Laser Sustained Plasmas,” Chapter 4, in Radziemski et al.,
`
`“Laser-Induced Plasmas and Applications,” CRC Press (1989) (“Keefer”) at 177
`
`(Ex. 1315).) (Eden Decl. at ¶ 44 (Ex. 1303).)
`
`C.
`
`Sustaining a plasma with a laser at various wavelengths, including
`those up to about 2000 nm, was well known in the art
`Gärtner’s laser 9 is a CO2 laser. (Gärtner at 5:3-5 (Ex. 1304).) CO2 lasers,
`
`14
`
`
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`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`which generally operate at a wavelength of 10.6 µm, were commonly used during
`
`the 1970s and 1980s because they provided high power and were cost-effective at
`
`the time. (See, e.g., U.S. Patent No. 4,780,608 to Cross at 5:44-47 (“[c]arbon
`
`dioxide lasers have been used since the output therefrom is readily absorbed by
`
`plasmas and they are available with very high power in both pulsed and cw
`
`operating modes”) (Ex. 1313).) However, it was recognized around the time of
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`Gärtner that shorter wavelength lasers could also be used. (See, e.g., Cross at 5:40-
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`52 (“lasers other than carbon dioxide may be used for the initiation and the
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`sustaining of the continuous optical discharge plasma. For example, a Nd-YAG
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`laser has been used for the initiation step. . . . Moreover, laser heating of a plasma
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`via the inverse Bremsstrahlung process varies as λ2, so that cw-laser sources
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`having shorter wavelengths such as Nd:Yag, for example, are absorbed less
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`effectively, and would require substantially greater cw-laser output power levels to
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`sustain the plasma.”) (Ex. 1313).) (Eden Decl. at ¶ 45 (Ex. 1303).)
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`By the mid-2000s, laser technology for shorter wavelengths (i.e., those up to
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`about 2000 nm) had improved significantly because of the development of
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`titanium-doped sapphire and rare earth-doped glass fiber lasers, making it easier
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`and more desirable to sustain plasmas with lasers in this wavelength range.4 For
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`example, “[s]ince the mid-1990s, high-power Yb-doped fiber lasers have
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`progressed rapidly, from 2 W in 1995, to 20 W and 35 W in 1997, and 110 W in
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`1999, the published record at the time of this writing.” (Michel Digonnet, Rare-
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`Earth-Doped Fiber Lasers and Amplifiers, 2d ed. (2001) (“Digonnet”) at 148
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`(citations omitted) (Ex. 1320).) The ytterbium-doped glass fiber laser typically
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`operates at a wavelength of approximately 1030 nm. (Eden Decl. at ¶ 46 (Ex.
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`1303).)
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`4 Patent Owner alleges that suitable commercial short wavelength lasers were
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`available for more than 20 years before the invention. (Case No. IPR2015-01362
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`at 3, 37, 50-52 (PTAB Mar. 1, 2016) (Paper 24).) However, the lasers that Patent
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`Owner cites as examples were generally bulky, extremely expensive, inefficient,
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`and exhibited low beam quality, which made them less suitable for use in
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`commercial light source products. Indeed, Zimakov (cited by Patent Owner in
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`IPR2015-01375, which is directed to the ’841 patent), acknowledges that “plasma-
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`based light source[s]” that are “used in microelectronics . . . became possible due
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`to the appearance of high-efficiency near-IR lasers, in particular diode lasers and
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`ytterbium fiber lasers.” (Zimakov at 68 (citing papers from 2006 and later) (Ex.
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`1337).) (Eden Decl. at ¶ 46 n.3 (Ex. 1303).)
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`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`By 2004, titanium-doped lasers were available that also produced at least 50
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`watts of power over a broad range of wavelengths in the near-infrared and middle
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`infrared regions (660-1180 nm). (Silfvast at 567 (Ex. 1309).) Also by 2004, 1,000
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`W (1 kW) could be obtained from a ytterbium-doped fiber laser. (See, e.g., Y.
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`Jeong et al., Ytterbium-doped large-core fibre laser with 1 kW of continuous-wave
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`output power, Electron. Lett. 40 (“Jeong”) at 1 (disclosing a “[y]tterbium-doped
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`large-core fibre laser with 1 kW of continuous-wave output power”) (Ex. 1327).)
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`Furthermore, it was known by the 1990’s that such high power fiber lasers could
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`be tuned to wavelengths between 970 nm and 1200 nm. (See, e.g., H.M. Pask et
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`al., IEEE J. Selected Topics in Quantum Electronics, vol. 1, at pp. 2, 12 (1995)
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`(Ex. 1328).) As a result, several compact and efficient near infrared lasers became
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`viable for sustaining plasma by the priority date for the ’000 patent. (Eden Decl. at
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`¶ 47 (Ex. 1303).)
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`Lasers with wavelengths of up to about 2000 nm were known to have
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`several advantages relative to longer wavelength lasers. For example, “Nd:YAG
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`light [at 1060 nm] can travel through glass (CO2 light cannot). This means that
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`high-quality glass lenses can be used to focus the beam down to a minimum spot
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`size.” (Handbook of Laser Technology and Applications, Vol. III (“Handbook of
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`Laser Tech.”) at 1601 (Ex. 1314).) Shorter wavelength light can also be focused to
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`a smaller spot size compared to longer wavelength light, which leads to increased
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`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`absorption of laser energy by the plasma. (See U.S. Patent No. 6,972,421 to
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`Melnychuk at 15:21-31 (“[i]n a laser-produce[d] plasma light source the laser
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`energy is absorbed by the inverse Bremsstrahlung mechanism. Due to their shorter
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`wavelength, excimer lasers can couple energy more efficiently to the target plasma
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`than near infrared or visible laser radiation from . . . solid state lasers. . . . Due to
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`their shorter wavelength, excimer lasers can (if desired) be focused more tightly to
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`a (diffraction-limited) spot size than longer wavelength (e.g., solid-state) lasers.
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`This increases the power density of the source.”) (Ex. 1331).)5 Additionally,
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`“quartz optical fibres can be employed to carry the beam [from Nd:YAG laser light
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`5 Patent Owner alleges that it was commonly accepted at the time of the alleged
`
`invention that optical energy absorbed by the plasma by the “inverse
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`bremsstrahlung” absorption mechanism decreased with wavelength, and so a
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`person of skill in the art would not have been inclined to use a shorter wavelength
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`laser. (See, e.g., Case No. IPR2015-01362 at 7-8 (PTAB Mar. 1, 2016) (Paper
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`24).) However, Patent Owner ignores the fact that shorter wavelength lasers can
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`be focused into a smaller spot size, which leads to increased absorption. A person
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`of ordinary skill in the art would have known to take into account all factors related
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`to absorption of laser energy, instead of focusing on a single factor as Patent
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`Owner has done. (Eden Decl. at ¶ 48 n.4 (Ex. 1303).)
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`U.S. Patent 9,048,000
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`at 1060 nm] relatively long distances (hundreds of metres).” (Handbook of Laser
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`Tech. at 1601 (Ex. 1314).) (Eden Decl. ¶¶ 48-51 (Ex. 1303).)
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`Shorter wavelength lasers can also be considerably smaller and more
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`efficient than CO2 lasers. For example, “[s]mall (2 to 3 feet long) CO2 lasers can
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`produce hundreds of watts of average power at an efficiency of 10%.” (Kelin
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`Kuhn, Laser Engineering, at 385 (1998) (Ex. 1321).) Therefore, in 1998 even a
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`“small” CO2 laser was 2 to 3 feet in length and these numbers do not include the
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`laser’s power supply. In contrast, fiber lasers also produced hundreds of watts by
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`2004, and did so in a much smaller package. (See, e.g., Jeong at 1 (Ex. 1327).)
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`Furthermore, since the laser is a fiber, it is a simple matter to direct the beam to the
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`chamber of the light source. It is also not unusual for the efficiency of a diode
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`laser-pumped fiber laser to exceed 50%. In fact, the ’000 patent acknowledges that
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`shorter wavelength lasers with these known advantages were “recently available.”
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`(’000 patent at 16:6-14) (Ex. 1301).) (Eden Decl. at ¶ 52 (Ex. 1303).)
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`Furthermore, it was known that “practically complete absorption of the laser
`
`radiation” could be achieved by tuning a laser to an atomic resonance transition,
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`and that such resonance transitions (such as the 823 nm line of xenon) can have
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`wavelengths less than 2000 nm. (See, e.g., I.M. Beterov et al., “Resonance
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`Radiation Plasma (Photoresonance Plasma),” Sov. Phys. Usp. 31 (6) at 539 (1988)
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`(“Beterov”) (“[t]he laser was tuned . . . to the resonance transition. . . .
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`U.S. Patent 9,048,000
`Petition for Inter Partes Review
`[P]ractically complete absorption of the laser radiation was attained. . . . This arises
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`fro