DOCKET NO.: 0107945-00246US29
`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 US, Inc., Excelitas Technologies Corp., and
`Qioptiq Photonics GmbH & Co. KG,
`Petitioners
`
`v.
`
`Energetiq Technology, Inc.,
`Patent Owner.
`
`Case IPR2016-00776
`
`
`
`PETITION FOR INTER PARTES REVIEW OF
`U.S. PATENT NO. 9,185,786
`CLAIMS 15, 20, 21, AND 25
`
`
`
`
`
`

`
`TABLE OF CONTENTS
`
`U.S. Patent 9,185,786
`Petition for Inter Partes Review
`
`
`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 .................................. 2 
`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 ’786 PATENT ............................................................ 5 
`A. 
`Summary of the Prosecution History .................................................... 7 
`VI.  CLAIM CONSTRUCTION .......................................................................... 10 
`A. 
`“light” .................................................................................................. 11 
`B. 
`“substantially continuous laser energy” .............................................. 13 
`VII.  THE CHALLENGED CLAIMS ARE UNPATENTABLE .......................... 14 
`A. 
`Laser Sustained Plasma Light Sources Were Known Long
`Before the Priority Date of the ’786 Patent ......................................... 14 
`Sustaining a plasma with a laser at various wavelengths,
`including those up to about 2000 nm, was well known in the art ....... 15 
`C.  Maintaining a plasma in an elongated form was well known in
`the art ................................................................................................... 23 
`VIII.  GROUNDS FOR FINDING THE CHALLENGED CLAIMS INVALID ... 26 
`A.  Ground 1: Claims 15, 20, and 21 Are Unpatentable Over
`Gärtner in View of Mourou and Silfvast ............................................. 27 
`1. 
`Independent Claim 15 .................................................................. 27 
`2.  Dependent Claim 20 ..................................................................... 43 
`
`B. 
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`

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`B. 
`
`U.S. Patent 9,185,786
`Petition for Inter Partes Review
`
`3.  Dependent Claim 21 ..................................................................... 44 
`4.  Reasons to Combine for Claims 20 and 21 .................................. 45 
`Ground 2: Claim 25 is Unpatentable Over Gärtner in view of
`Mourou, Silfvast, and Uhlenbusch ...................................................... 46 
`1.  Dependent Claim 25 ..................................................................... 46 
`Ground 3: Claims 15, 20, and 21 Are Unpatentable Over
`Gärtner in View of Kensuke and Silfvast ........................................... 49 
`1. 
`Independent Claim 15 .................................................................. 50 
`2.  Dependent Claim 20 ..................................................................... 57 
`3.  Dependent Claim 21 ..................................................................... 57 
`4.  Reasons to Combine for Claims 20 and 21 .................................. 57 
`D.  Ground 4: Claim 25 is Unpatentable over Gärtner in view of
`Kensuke, Silfvast, and Uhlenbusch ..................................................... 58 
`1.  Dependent Claim 25 ..................................................................... 58 
`IX.  RESPONSE TO ARGUMENTS RAISED BY PATENT OWNER
`REGARDING OBJECTIVE INDICIA OF NON-OBVIOUSNESS ............ 59 
`CONCLUSION .............................................................................................. 60 
`
`C. 
`
`X. 
`
`
`ii
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`

`
`U.S. Patent 9,185,786
`Petition for Inter Partes Review
`
`I. MANDATORY NOTICES
`A. Real Parties-in-Interest
`ASML Netherlands B.V., ASML US, Inc., Excelitas Technologies Corp.,
`
`and Qioptiq Photonics GmbH & Co. KG (“Petitioners”) are the real parties-in-
`
`interest.
`
`B. Related Matters
`U.S. Patent No. 9,185,786 (“the ’786 patent,” Ex. 1101) is one member of a
`
`patent family of continuation and continuation-in-part applications. Exhibit 1102
`
`shows the members of this patent family and the relationships among them.
`
`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”); 8,969,841 (“the ’841 patent”) and
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`9,048,000 (“the ’000 patent”) in Case Nos. IPR2015-01300, IPR2015-01303,
`
`IPR2015-01377, IPR2016-00583, IPR2016-00584, IPR2016-00585, IPR2015-
`
`01279, IPR2016-00570, IPR2016-00575, IPR2015-00576, IPR2016-00578,
`
`IPR2016-00579, IPR2015-01277, IPR2016-00554, IPR2016-00556, IPR2016-
`
`00555, IPR2015-01368, IPR2016-00565, IPR2016-00566, IPR2015-01362,
`
`IPR2016-00127, IPR2015-01375, and IPR2016-00126. The status of the other
`
`proceedings is summarized in Ex. 1112.
`
`Petitioners are also filing additional petitions on the ’841, ’000, and ’786
`
`1
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`

`
`U.S. Patent 9,185,786
`Petition for Inter Partes Review
`patents. 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
`
`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.
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`2
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`

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`U.S. Patent 9,185,786
`Petition for Inter Partes Review
`III. OVERVIEW OF CHALLENGE AND RELIEF REQUESTED
`Pursuant to Rules 42.22(a)(1) and 42.104 (b)(1)-(2), Petitioners challenge
`
`claims 15, 20, 21, and 25 of the ’786 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. 1103),
`
`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
`
`(“Gärtner,” Ex. 1104), with English Translation, and is prior art to the ʼ786
`
`patent under 35 U.S.C. § 102(b).
`
`2. International Publication WO-2004097520, published November 11, 2004
`
`(“Mourou,” Ex. 1114), and is prior art to the ʼ786 patent under 35 U.S.C. §
`
`102(b).
`
`3. Japanese Patent Publication No. 2006010675A, published January 12, 2006
`
`(“Kensuke,” Ex. 1105), with English Translation, and is prior art to the ʼ786
`
`3
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`

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`U.S. Patent 9,185,786
`Petition for Inter Partes Review
`
`patent under 35 U.S.C. § 102(a) and 102(b).
`
`4. William T. Silfvast, Laser Fundamentals, 2d ed., published in 2004 (“Silfvast,”
`
`Ex. 1106) and is prior art to the ʼ786 patent under 35 U.S.C. § 102(b).
`
`C. Relief Requested
`Petitioners request that the Patent Trial and Appeal Board cancel the
`
`challenged claims because they are unpatentable under 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 ’786 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. ¶ 25 (Ex. 1103).)
`
`The ’786 patent is entitled “Laser-Driven Light Source.” The patent states
`
`that the alleged “invention relates to methods and apparatus for providing a laser-
`
`driven light source.” (’786 patent, 1:20-24 (Ex. 1101).) That 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. ¶ 26 (Ex. 1103).)
`
`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
`
`4
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`

`
`U.S. Patent 9,185,786
`Petition for Inter Partes Review
`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 ’786 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. ¶ 27 (Ex. 1103).)
`
`V. OVERVIEW OF THE ’786 PATENT
`The ’786 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 Fig. 1 below, the light source includes a sealed pressurized chamber
`
`containing gas (green), an ignition source for ionizing the gas (blue), and a laser
`
`(red) that sustains a light-generating plasma. (’786 patent, 14:40-18:11 (Ex.
`
`1101).) The ’786 continuation adds claims that require that the laser operate within
`
`a wavelength of up to about 2000 nm and that the plasma be maintained in an
`
`elongated form. (Eden Decl. ¶ 28 (Ex. 1103).)
`
`5
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`

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`U.S. Patent 9,185,786
`Petition for Inter Partes Review
`
`ʼ786 Patent, Figure 1 (Ex. 1101)
`
`
`
`As discussed below, there was nothing new in 2006 about 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 less than about 2000 nm, nor was there anything new about
`
`maintaining the plasma in an elongated form with a length less than about 2mm.
`
`As the patent admits, efficient, cost effective, and high power lasers in the claimed
`
`wavelength range were “recently available.” (’786 patent, 16:6-14 (Ex. 1101).)
`
`Mourou and Kensuke provide examples of systems that provide energy to a plasma
`
`with a laser operating within the claimed wavelength range, while Gärtner provides
`
`an example of a system that maintains a plasma in an elongated form. Uhlenbusch
`
`provides an example of a system that maintains an elongated plasma with a plasma
`
`length of less than about 2 mm. Furthermore, Silfvast shows that the laser used by
`
`6
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`

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`U.S. Patent 9,185,786
`Petition for Inter Partes Review
`Mourou and Kensuke could be operated as a continuous wave laser. It would have
`
`been obvious to combine (i) Mourou, Silfvast and Uhlenbusch, or (ii) Kensuke,
`
`Silfvast and Uhlenbusch with Gärtner to arrive at the claimed invention. (Eden
`
`Decl. ¶ 30 (Ex. 1103).)
`
`A.
`
`Summary of the Prosecution History
`
`The ’786 patent (Ex. 1101) issued from U.S. Patent Appl. No. 14/448,258,
`
`filed on July 31, 2014. The ’786 patent is a continuation of the ’000 patent, which
`
`is a continuation of the ’138 patent, which is a continuation-in-part of U.S. Patent
`
`No. 7,989,786 (“the ’9786 patent”), which is a continuation-in-part of the ’455
`
`patent, which is a continuation-in-part of the ’982 patent, filed March 31, 2006.
`
`(See Chart of Related Patents (Ex. 1102).)
`
`During prosecution, the Examiner rejected claims 1, 8, 15, and 21 as being
`
`anticipated by Hertz (Ex. 1126), which disclosed an “elongated EUV emitting
`
`plasma.” (December 15, 2014 Non-Final Office Action, 2-3 (Ex. 1108).) The
`
`Examiner also rejected other claims over Hertz in view of Ahmad (Ex. 1127),
`
`which disclosed a light source that “forms a plasma column 71 of high density
`
`(with a length from 1 mm to 50 mm and a diameter from 0.2 to 4 mm).” (Non-
`
`Final Office Action, 6-7 (Ex. 1108).) The Examiner also rejected the challenged
`
`claims 1, 6, 8, and 13 as being “not patentably distinct” from claims in other
`
`7
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`

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`U.S. Patent 9,185,786
`Petition for Inter Partes Review
`Energetiq patents and patent applications.1 (Id. at 22-39.)
`
`On June 15, 2015, the Patent Owner amended the independent claims to
`
`incorporate three additional features: (i) that the pressurized chamber be
`
`configured to contain an ionized gas “at a pressure greater than 10 atmospheres
`
`during operation;” (ii) that the laser be a “substantially continuous” laser that
`
`provides a beam of laser energy “within a wavelength range of up to about 2000
`
`nm;” and (iii) that the light generated by the plasma have “wavelengths of at least
`
`than 50 nm. [sic].” (Jun. 15, 2015 Patent Owner Response, 2 (Ex. 1109).) The
`
`Patent Owner argued that these features, which also appear in claim 1 of the ’841
`
`patent and claims 1, 15, and 18 of the ’000 patent for which IPRs have been
`
`instituted, distinguished the prior art, but did not address the elongated plasma
`
`limitations. (See id. at 6-9 (Ex. 1109); Case No. IPR2015-01362 at 3-4 (PTAB
`
`Nov. 30, 2015) (Paper 12) (instituting claim 1 of the ’841 patent); Case No.
`
`IPR2015-01375 at 3-4 (PTAB Nov. 30, 2015) (Paper 13) (instituting claims 1, 15,
`
`and 18 of the ’000 patent).) As part of this amendment, Patent Owner also added
`
`claim 25, which recites a plasma having a length of no more than about 2 mm, but
`
`did not argue that this feature made claim 25 separately patentable. The Patent
`
`1 These other Energetiq patents and patent applications include patents for which
`
`the Board has already instituted IPR petitions filed by Petitioners, such as the ’982,
`
`’455, ’841, ’000, and ’138 patents. (See supra § I.B.)
`
`8
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`

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`U.S. Patent 9,185,786
`Petition for Inter Partes Review
`Owner also filed a terminal disclaimer, which terminally disclaimed the ’786
`
`patent over the ’982 patent, the ’455 patent, the ’9786 patent, the ’841 patent, the
`
`’000 patent, and the ’138 patent. (July 31, 2014 Terminal Disclaimer (Ex. 1118).)
`
`On June 30, 2015, the Examiner allowed the claims. (Jun. 30, 2015 Notice
`
`of Allowability (Ex. 1110).) In allowing the claims, the Examiner noted that the
`
`prior art, such as Hertz, disclosed “maintain[ing] the plasma in an elongated form[]
`
`having a plasma length that is greater than that of a plasma diameter.” (Id. at 2.)
`
`The Examiner, however, did not consider Silfvast, nor was the Examiner provided
`
`a complete English translation of Kensuke.2 The prosecution history of the ’786
`
`patent provides no indication that the Examiner appreciated the significance of
`
`Gärtner (submitted on March 11, 2015, only three months before the claims were
`
`allowed), or Mourou (submitted on August 6, 2015, months after the claims were
`
`allowed). None of these references were cited by the Examiner.
`
`2 Kensuke was included in an Information Disclosure Statement filed by applicant
`
`on July 31, 2014. 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
`
`of less than 2000 nm to create a plasma that produces a light with a wavelength
`
`greater than 50 nm, but the abstract does not provide this disclosure. (See infra §
`
`Error! Reference source not found..)
`
`9
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`U.S. Patent 9,185,786
`Petition for Inter Partes Review
`As discussed below, Gärtner in view of Mourou and Silfvast, and Gärtner in
`
`view of Kensuke and Silfvast (plus Uhlenbusch for claim 25) each render the
`
`challenged claims unpatentable as obvious.
`
`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
`
`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
`
`10
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`U.S. Patent 9,185,786
`Petition for Inter Partes Review
`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. ¶ 36 (Ex.
`
`1103).)
`
`“light”
`
`A.
` The term “light” is recited in challenged claim 15, from which all other
`
`challenged claims 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.3 (Case No.
`
`IPR2015-01375 at 6 (PTAB Nov. 30, 2015) (Paper 13).) (Eden Decl. ¶ 37 (Ex.
`
`1103).) This construction is equivalent to the Petitioners’ proposed construction
`
`for the term “light” in that proceeding.
`
`The ordinary and customary meaning of “light”4 is electromagnetic radiation
`
`
`3 The ’786 patent is a continuation of the ’000 patent.
`
`4 The term “light” is sometimes used more narrowly to refer only to visible light.
`
`However, references to “ultraviolet light” in the ’786 patent make clear that the
`
`broader meaning is intended because ultraviolet light has a wavelength shorter than
`
`11
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`

`
`U.S. Patent 9,185,786
`Petition for Inter Partes Review
`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
`
`(700 nm to 1,000 nm (1µm)), middle infrared (1 µm to 10 µm), or far infrared (10
`
`µm to 1,000 µm) regions of the spectrum. (See, e.g., Silfvast, 4 (Ex. 1106).) 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. 1107).) (Eden Decl.
`
`¶ 38 (Ex. 1103).)
`
`The ’786 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 ’786 patent states that
`
`parameters such as the wavelength of the light from a light source “vary depending
`
`upon the application.” (’786 patent, 1:36-38 (Ex. 1101).) The specification
`
`describes “ultraviolet light” as an example of the type of light that can be
`
`generated. (See, e.g., id. at 18:34-36, 17:12-14.) (Eden Decl. ¶ 39 (Ex. 1103).)
`
`Therefore, the term “light” should be construed to mean “electromagnetic
`
`radiation in the ultraviolet (“UV”), extreme UV, vacuum UV, visible, near
`
`that of visible light. (See, e.g., ’786 patent, 2:26; 3:44; 8:12; 16:46; 19:55; 21:18)
`
`(Ex. 1101).) (See Eden Decl. ¶ 38 n.4 (Ex. 1103).)
`
`12
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`U.S. Patent 9,185,786
`Petition for Inter Partes Review
`infrared, middle infrared, or far infrared regions of the spectrum, having
`
`wavelengths within the range of 10 nm to 1,000 µm.” (Eden Decl. ¶ 40 (Ex.
`
`1103).)
`
`“substantially continuous laser energy”
`
`B.
`The term “substantially continuous laser energy” is recited in challenged
`
`claim 15, from which all other challenged claims depend. This term should be
`
`construed to encompass laser energy from a continuous wave laser as well as a
`
`high pulse rate laser, similar to how the Board construed the term “substantially
`
`continuous laser” in its Decision on Institution in an IPR directed to the related
`
`’841 patent. (Case No. IPR2015-01362 at 6-7 (PTAB Nov. 30, 2015) (Paper 12).)
`
`(Eden Decl. ¶ 41 (Ex. 1103).)
`
`The specification of the ’786 patent indicates that substantially continuous
`
`laser energy can encompass laser energy from a continuous wave laser as well as a
`
`high pulse rate laser. (’786 patent, 15:60-62 (high pulse rate laser or continuous
`
`wave laser); 16:15-18 (“high pulse rate laser source that provides substantially
`
`continuous laser energy”); 4:53-55 (a “continuous-wave laser emits radiation
`
`continuously or substantially continuously rather than in short bursts, as in a pulsed
`
`laser.”) (Ex. 1101).) (Eden Decl. ¶ 42 (Ex. 1103).)
`
`13
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`U.S. Patent 9,185,786
`Petition for Inter Partes Review
`VII. THE CHALLENGED CLAIMS ARE UNPATENTABLE
`The challenged claims recite and claim features that were known in the art
`
`prior to the earliest priority date, and are obvious in view of the prior art.
`
`A. Laser Sustained Plasma Light Sources Were Known Long Before
`the Priority Date of the ’786 Patent
`
`When the application that led to the ’786 patent was filed, there was nothing
`
`new or inventive about a light source using a laser operating at certain wavelengths
`
`to 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. ¶ 44
`
`(Ex. 1103).)
`
`For example, Gärtner, which published in 1985, discloses a light source with
`
`the same features claimed in the ’786 patent: (1) a sealed chamber and (2) a laser
`
`that sustains a light-generating plasma . (Compare Gärtner, 4:31-35, 5:1-9, Fig. 1
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`(Ex. 1104) with ’786 patent, 2:8-15, Fig. 1 (Ex. 1101).) For example, Figure 1 of
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`Gärtner below depicts a “gas-tight chamber 1” (green); “laser 10” (blue) for
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`generating the plasma 14; and a “laser 9” (red) for sustaining the plasma (yellow)
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`and producing a light. (Gärtner, 4-5, Fig. 1 (Ex. 1104).) (Eden Decl. ¶ 45 (Ex.
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`1103).)
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`’786 patent, Fig. 1 (Ex. 1101)
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`Gärtner, Fig. 1 (Ex. 1104)
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`B.
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`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, 5:3-5 (Ex. 1104).) CO2 lasers,
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`which generally operate at a wavelength of 10.6 µm, were commonly used during
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`the 1970s and 1980s because they provided high power and were cost-effective at
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`the time. (See, e.g., Cross, 5:44-47 (“Carbon dioxide lasers have been used since
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`the output therefrom is readily absorbed by plasmas and they are available with
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`very high power in both pulsed and cw operating modes.”) (Ex. 1115).) However,
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`it was recognized around the time of Gärtner that shorter wavelength lasers could
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`also be used. (See, e.g., id. at 5:40-53 (“[L]asers other than carbon dioxide may be
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`used for the initiation and the sustaining of the continuous optical discharge
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`plasma. For example, a Nd-YAG laser has been used for the initiation step. . . .
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`Moreover, laser heating of a plasma via the inverse Bremsstrahlung process varies
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`as λ2, so that cw-laser sources having shorter wavelengths such as Nd:Yag, for
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`U.S. Patent 9,185,786
`Petition for Inter Partes Review
`example, are absorbed less effectively, and would require substantially greater cw-
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`laser output power levels to sustain the plasma.”)) (Eden Decl. ¶ 46 (Ex. 1103).)
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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 range5. 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.” (Digonnet, 148 (citations
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`5 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 at
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`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 to
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`the appearance of high-efficiency near-IR lasers, in particular diode lasers and
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`ytterbium fiber lasers.” (Zimakov, 68 (citing papers from 2006 and later) (Ex.
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`1138).) (Eden Decl. ¶ 47 n.5 (Ex. 1103).)
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`omitted) (Ex. 1121).) The ytterbium-doped glass fiber laser typically operates at a
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`wavelength of 1030 nm. By 2004, titanium-doped lasers were available that
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`produced at least 50 watts of power over a broad range of wavelengths in the near-
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`infrared and middle infrared regions (660-1180 nm). (Silfvast, 567 (Ex. 1106).)
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`Also by 2004, 1,000 W (1 kW) could be obtained from a ytterbium-doped fiber
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`laser. (Jeong, 1 (disclosing a “[y]tterbium-doped large-core fibre laser with 1 kW
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`of continuous-wave output power”) (Ex. 1124).) Furthermore, it was known by the
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`1990s that such high power fiber lasers could be tuned to wavelengths between 970
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`nm and 1200 nm (see Pask, 2, 12 (Ex. 1125).) As a result, several compact and
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`efficient near infrared lasers became viable for sustaining plasma by the priority
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`date for the ’786 patent. (Eden Decl. ¶ 47 (Ex. 1103).)
`
` Lasers operating in the shorter wavelength range (up to about 2000 nm)
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`were known to have several advantages relative to longer wavelength lasers. For
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`example, “Nd:YAG light [at 1060 nm] can travel through glass (CO2 light cannot).
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`This means that high-quality glass lenses can be used to focus the beam down to a
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`minimum spot size.” (Handbook of Laser Tech., 1601 (Ex. 1116).) Shorter
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`wavelength light can also be focused to a smaller spot size compared to longer
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`wavelength light, which leads to increased absorption of laser energy into the
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`plasma. (See Melnychuk, 15:21-31 (“In a laser-produce[d] plasma light source the
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`laser energy is absorbed by the inverse Bremsstrahlung mechanism. Due to their
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`shorter wavelength, excimer lasers can couple energy more efficiently to the target
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`plasma than near infrared or visible laser radiation from…solid state lasers…. Due
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`to their shorter wavelength, excimer lasers can (if desired) be focused more tightly
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`to 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. 1113).)6 Additionally,
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`“quartz optical fibres can be employed to carry the beam [from Nd:YAG laser light
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`at 1060 nm] relatively long distances (hundreds of metres) . . . .” (Handbook of
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`Laser Tech., 1601 (Ex. 1016).) (Eden Decl. ¶¶ 48-51 (Ex. 1103).)
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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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`6 Patent Owner alleges that it was commonly accepted at the time of the alleged
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`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 24).)
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`However, Patent Owner ignores the fact that shorter wavelength lasers can be
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`focused into a smaller spot size, which leads to increased absorption. A person of
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`ordinary skill in the art would have known to take into account all factors related to
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`absorption of laser energy, instead of focusing on a single factor as Patent Owner
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`has done. (Eden Decl. ¶ 48 n.6 (Ex. 1103).)
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`produce hundreds of watts of average power at an efficiency of 10%.” (Kuhn, 385
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`(Ex. 1122).) Therefore, in 1998 even a “small” CO2 laser was 2 to 3 feet in length
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`and these numbers do not include the laser’s power supply. In contrast, fiber lasers
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`also produced hundreds of watts by 2004, and did so in a much smaller package.
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`(See, e.g., Jeong, 1 (Ex. 1124).) Furthermore, since the laser is a fiber, it is a
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`simple matter to direct the beam to the chamber of the light source. It is also not
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`unusual for the efficiency of a diode laser-pumped fiber laser to exceed 50%. In
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`fact, the ’786 patent acknowledges that shorter wavelength lasers with these known
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`advantages were “recently available.” (’786 patent, 16:6-14 (Ex. 1101).) (Eden
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`Decl. ¶ 52 (Ex. 1103).)
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`Furthermore, it was known that “practically complete absorption of the