DOCKET NO.: 0107945.00235US7
`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., EXCELITAS TECHNOLOGIES CORP., AND QIOPTIQ
`PHOTONICS GMBH & CO. KG,
`Petitioners
`
`v.
`
`ENERGETIQ TECHNOLOGY, INC.,
`Patent Owner.
`
`Case IPR2015-01377
`
`
`PETITION FOR INTER PARTES REVIEW OF
`U.S. PATENT NO. 7,435,982
`CLAIMS 23 AND 60
`
`
`
`
`
`
`
`
`

`

`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`TABLE OF CONTENTS
`
`Page
`
`I. 
`
`IV. 
`V. 
`
`MANDATORY NOTICES ............................................................................. 1 
`A. 
`Real Parties-in-Interest .......................................................................... 1 
`B. 
`Related Matters ...................................................................................... 1 
`C. 
`Counsel .................................................................................................. 1 
`D. 
`Service Information ............................................................................... 2 
`CERTIFICATION OF GROUNDS FOR STANDING .................................. 2 
`II. 
`III.  OVERVIEW OF CHALLENGE AND RELIEF REQUESTED .................... 2 
`A.  Grounds for Challenge .......................................................................... 2 
`B. 
`Prior Art Patents and Printed Publications Relied Upon ...................... 3 
`C. 
`Relief Requested .................................................................................... 3 
`PERSON OF ORDINARY SKILL IN THE ART .......................................... 3 
`OVERVIEW OF THE ’982 PATENT ............................................................ 4 
`A. 
`Summary of the Prosecution History .................................................... 6 
`VI.  CLAIM CONSTRUCTION ............................................................................ 7 
`A. 
`“Light source” ....................................................................................... 8 
`B. 
`“High brightness light” ........................................................................ 10 
`VII.  THE CHALLENGED CLAIMS ARE INVALID ......................................... 13 
`A. 
`Laser Sustained Plasma Light Sources Were Known Long
`Before the Priority Date of the ’982 Patent ......................................... 13 
`Sustaining a plasma with a laser emitting at least one
`wavelength of electromagnetic energy that is strongly absorbed
`by the ionized medium was well known in the art .............................. 14 
`VIII.  GROUNDS FOR FINDING THE CHALLENGED CLAIMS INVALID ... 20 
`A.  Ground 1: Claims 23 and 60 Are Obvious Over Gärtner in
`View of Beterov .................................................................................. 20 
`1.  Gärtner and Beterov are prior art references that were not
`considered by the Patent Office during examination ................... 20 
`2.  Overview of Gärtner ..................................................................... 21 
`3.  Overview of Beterov .................................................................... 24 
`
`B. 
`
`i
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`

`

`B. 
`
`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`4.  Claim 23 ....................................................................................... 28 
`5.  Claim 60 ....................................................................................... 40 
`Ground 2: Claims 23 and 60 Are Obvious Over Gärtner in
`View of Wolfram ................................................................................. 43 
`1.  Gärtner and Wolfram are prior art references that were not
`considered by the Patent Office during examination ................... 43 
`2.  Claim 23 ....................................................................................... 44 
`3.  Claim 60 ....................................................................................... 51 
`IX.  RESPONSE TO ARGUMENTS RAISED BY PATENT OWNER IN ITS
`PRELIMINARY INJUNCTION MOTION .................................................. 53 
`A. 
`Patent Owner’s Arguments Regarding ”High Brightness Light” ....... 53 
`B. 
`Patent Owner’s Arguments Regarding Objective Indicia of
`Non-Obviousness ................................................................................ 58 
`CONCLUSION .............................................................................................. 60 
`
`X. 
`
`
`
`ii
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`

`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`
`I. MANDATORY NOTICES
`A. Real Parties-in-Interest
`ASML Netherlands B.V., Excelitas Technologies Corp., and Qioptiq
`
`Photonics GmbH & Co. KG (“Petitioners”) are the real parties-in-interest.
`
`B. Related Matters
`U.S. Patent No. 7,435,982 (“the ’982 patent,” Ex. 1201) is one member of a
`
`patent family of continuation and continuation in part applications. Exhibit 1202
`
`shows the members of this patent family and the relationships among them.
`
`Petitioners are also seeking inter partes review of additional claims of the ’982
`
`patent and of related U.S. Patent Nos. 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 9,048,000 (“the ʼ000 patent”). Petitioners request that the inter partes reviews
`
`of the ’982, ’455, ’943,’138, ʼ841, and ʼ000 patents be assigned to the same Panel
`
`for administrative efficiency.
`
`The following litigation matter would affect or be affected by a decision in
`
`this proceeding: Energetiq Technology, Inc. v. ASML Netherlands B.V., et al, Civil
`
`Action No. 1:15-cv-10240-LTS (D. Mass.).
`
`C. Counsel
`Lead Counsel: Donald R. Steinberg (Registration No. 37,241)
`
`First Backup Counsel: David L. Cavanaugh (Registration No. 36,476)
`
`Second Backup Counsel: Michael H. Smith (Registration No. 71,190)
`
`1
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`

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`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`
`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.
`
`III. OVERVIEW OF CHALLENGE AND RELIEF REQUESTED
`Pursuant to Rules 42.22(a)(1) and 42.104(b)(1)-(2), Petitioners challenge
`
`claims 23 and 60 of the ’982 patent (“the challenged claims”) and request that each
`
`challenged claim be cancelled. Petitioners have separately challenged claims 1 and
`
`37, from which claims 23 and 60 depend, in IPR Nos. 2015-01300 and 2015-
`
`01303.
`
`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. 1203),
`
`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. See 35 U.S.C. §
`
`2
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`

`

`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`
`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. 1204), and is prior art to the ʼ982 patent
`
`under 35 U.S.C. § 102(a) and (b).
`
`2. I.M. Beterov et al., Resonance radiation plasma (photoresonance plasma), Sov.
`
`Phys. Usp. 31 (6), 535 (1988) (“Beterov,” Ex. 1216), and is prior art to the ’138
`
`patent under 35 U.S.C. § 102(a) and (b).
`
`3. U.S. Patent No. 4,901,330, filed July 20, 1988 (“Wolfram,” Ex. 1215), and is
`
`prior art to the ʼ138 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 35 U.S.C. § 103.
`
`IV. PERSON OF ORDINARY SKILL IN THE ART
`A person of skill in the art at the time of the alleged invention of the ’982
`
`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 plasma, or a master’s degree
`
`in physics, electrical engineering, or an equivalent field and 4-5 years of work
`
`experience with lasers and plasma. (Eden Decl. ¶ 23 (Ex. 1203).)
`
`3
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`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`
`V.
`
` OVERVIEW OF THE ’982 PATENT
`
`The ’982 patent 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, reproduced below, the light source includes: (1) a chamber 128
`
`(green), (2) an ignition source 140 (blue) for generating a plasma 132, and (3) a
`
`laser 104 (red) for providing energy to the plasma 132 to produce a high brightness
`
`light 136. (’982 patent, 1:46-50 (Ex. 1201).) (Eden Decl. ¶ 24 (Ex. 1203).) The
`
`’982 patent identifies several types of “ignition sources,” such as “electrodes”
`
`(shown below) and “pulsed lasers” (not shown). (’982 Patent, 7:7-24 (Ex. 1201).)
`
`(Eden Decl. ¶ 24 (Ex. 1203).)
`
`According to the ’982 patent, prior art light sources relied upon electrodes to
`
`both generate and sustain the plasma, which resulted in wear and contamination.
`
`(’982 patent, 1:20-40 (Ex. 1201).) Thus, a need allegedly arose for a way to
`
`sustain plasma without relying on an electrical discharge from electrodes. (’982
`
`
`
`4
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`

`

`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`patent, 1:20-40 (Ex. 1201).) The alleged invention involves using a laser to
`
`provide energy to sustain the plasma to produce a “high brightness” light. (See,
`
`e.g., ’982 patent, 1:46-50 (Ex. 1201).) (Eden Decl. ¶ 25 (Ex. 1203).)
`
`The alleged invention also involves using a laser to emit a wavelength that is
`
`“strongly absorbed” by the ionized medium. (’982 patent, 2:20-23, 3:33-35, 4:40-
`
`43 (Ex. 1001).) However, the ’982 patent does not define the term “strongly
`
`absorbed.”1 (Eden Decl. ¶ 26 (Ex. 1203).)
`
`As discussed below, there was nothing new about sustaining a plasma with a
`
`laser to produce high brightness light. Multiple prior art references, including
`
`Gärtner, disclosed laser-sustained plasma light sources with the same elements as
`
`the ’982 patent: a chamber, an ignition source, and a laser. (Eden Decl. ¶ 27 (Ex.
`
`1203).)
`
`Additionally, there was nothing new about operating the laser at a
`
`wavelength that is strongly absorbed. For example, Beterov disclosed tuning a
`
`laser onto or near a wavelength corresponding to a resonance at which the laser
`
`energy is strongly absorbed. Similarly, Wolfram disclosed tuning a laser at a
`
`1 Petitioners note that in an infringement proceeding in which the required strength
`
`of absorption were at issue, claims reciting “strongly absorbed” could be invalid
`
`under 35 U.S.C. § 112, second paragraph for indefiniteness because the patent does
`
`not specify how strong the absorption must be.
`
`5
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`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`wavelength within 2 nm or less of an absorption peak that is strongly absorbed by
`
`an active medium or lasant material such as ions of chromium, titanium, or one of
`
`the rare earth elements. (Eden Decl. ¶ 28 (Ex. 1203).)
`
`A.
`
`Summary of the Prosecution History
`
`The ’982 patent issued from U.S. Patent Appl. No. 11/395,523, filed on
`
`March 31, 2006. On August 25, 2008, all the claims were allowed without
`
`rejection. The ’982 patent issued on October 14, 2008. (’982 Patent (Ex. 1201).)
`
`(Eden Decl. ¶ 29 (Ex. 1203).)
`
`In the Notice of Allowability, the Examiner explained that prior art to
`
`Hoshino disclosed “a light source which has a laser that generates a plasma,” and
`
`prior art to Sato disclosed a “light source where a laser beam excites gas (for
`
`emitting UV and EUV light) that is sealed in a bulb tube.” (Notice of Allowability
`
`dated Aug. 28, 2008 at 3 (Ex. 1207).) Thus, the Examiner recognized that using a
`
`laser to generate a plasma light source was not inventive. (Eden Decl. ¶ 30 (Ex.
`
`1203).)
`
`The Examiner nonetheless allowed the claims because the Examiner was not
`
`aware of prior art that disclosed the combination of an ignition source that
`
`generates the plasma and a laser beam that sustains the plasma. (Notice of
`
`Allowability dated Aug. 28, 2008 at 3 (Ex. 1207).) (Eden Decl. ¶ 31 (Ex. 1203).)
`
`The Examiner did not consider Gärtner, which was not of record during the
`
`6
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`

`

`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`prosecution of the ’982 patent. Gärtner discloses an ignition source that generates
`
`the plasma and a laser beam that sustains the plasma to produce a high brightness
`
`light. In fact, as further discussed below, high brightness light sources with
`
`ignition sources that generate the plasma and laser beams that sustain the plasma
`
`were well-known long before the priority date of the ’982 patent. (Eden Decl. ¶ 32
`
`(Ex. 1203).)
`
`VI. CLAIM CONSTRUCTION
`Claim terms in inter partes review are given the “broadest reasonable
`
`construction in light of the specification of the patent in which [they] appear[].” 37
`
`C.F.R. § 42.100(b); see Office Patent Trial Practice Guide, 77 Fed. Reg. 48,756,
`
`48,764, 48,766 (Aug. 14, 2012). Claim terms are given their ordinary and
`
`customary meaning as would be understood by a person of ordinary skill in the art
`
`at the time of the invention and in the context of the entire patent disclosure. In re
`
`Translogic Tech., Inc., 504 F.3d 1249, 1257 (Fed. Cir. 2007). If the specification
`
`sets forth an alternate definition of a term with reasonable clarity, deliberateness,
`
`and precision, the patentee’s lexicography governs. In re Paulsen, 30 F.3d 1475,
`
`1480 (Fed. Cir. 1994).
`
`Should the Patent Owner, seeking to avoid the prior art, contend that the
`
`claim terms have a construction different from their broadest reasonable
`
`construction, the appropriate course is for the Patent Owner to seek to amend the
`
`7
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`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`claims to expressly correspond to its contentions in this proceeding. See 77 Fed.
`
`Reg. 48,764, 48,766-67.
`
`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.
`
`“Light source”
`
`A.
`The term “light source” appears in claims 23 and 60. “Light source” should
`
`be construed to mean “a source of electromagnetic radiation in the extreme
`
`ultraviolet (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 (1
`
`µm)), middle infrared (1 µm to 10 µm), or far infrared (10 µm to 1000 µm) regions
`
`of the spectrum.” (Eden Decl. ¶ 33 (Ex. 1203).)
`
`The ordinary and customary meaning of “light source”2 is a source of
`
`2 The term “light” is sometimes used more narrowly to refer only to visible light.
`
`However, references to “ultraviolet light” in the ’982 patent make clear that the
`
`broader meaning is intended because ultraviolet light has a wavelength shorter than
`
`that of visible light. (See, e.g., ’982 patent, 6:47-49; 7:65-67; 8:6-9; 8:37-39 (Ex.
`
`1201).) (See Eden Decl. ¶ 34 n.1 (Ex. 1203).)
`
`8
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`

`

`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`electromagnetic radiation in the extreme ultraviolet (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 (1 µm)), middle infrared (1 µm to 10 µm),
`
`or far infrared (10 µm to 1000 µm) regions of the spectrum. (See, e.g., William T.
`
`Silfvast, “Laser Fundamentals” at 4 (“Silfvast”) (Ex. 1209).) The Patent Owner
`
`publishes a data sheet which is consistent with the ordinary and customary
`
`meaning in referring to EUV wavelength as within the meaning of “light source.”
`
`(See, e.g., Energetiq EQ-10M Data Sheet at 2 (describing Energetiq’s EQ-10
`
`product operating at 13.5 nm as an “EUV [Extreme Ultraviolet] Light Source”)
`
`(Ex. 1208).) (Eden Decl. ¶ 34 (Ex. 1203).)
`
`The ’982 patent does not provide a definition of the term “light source” and
`
`uses the term consistent with the ordinary and customary meaning of the term. The
`
`’982 patent states that parameters such as the wavelength of the light from a light
`
`source will vary depending upon the application. (’982 patent, 1:18-20 (Ex.
`
`1201).) The specification describes “ultraviolet light” as an example of the type of
`
`light that can be generated: “emitted light 136 (e.g., at least one or more
`
`wavelengths of ultraviolet light).” (’982 patent, 7:65-67 (Ex. 1201); see also id. at
`
`6:47-49 (discussing the ultraviolet light 136 generated by the plasma 132 of the
`
`light source 100), 8:6-9, 8:37-39.) (Eden Decl. ¶ 35 (Ex. 1203).)
`
`Therefore, the term “light source” should be construed to mean “a source of
`
`9
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`

`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`electromagnetic radiation in the extreme ultraviolet (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 1000 µm) regions of the spectrum.” (Eden Decl. ¶ 36
`
`(Ex. 1203).)
`
` “High brightness light”
`
`B.
`All the challenged claims recite the term “high brightness light.” For
`
`purposes of this proceeding, the term “high brightness light”3 should be construed
`
`to include “light sufficiently bright to be useful for inspection, testing or measuring
`
`properties associated with semiconductor wafers or materials used in the
`
`fabrication of wafers, or as a source of illumination in a lithography system used in
`
`the fabrication of wafers, microscopy systems, photoresist curing systems, or
`
`3 For purposes of this proceeding, it is sufficient to interpret “high brightness light”
`
`as Petitioners explain above and each prior art reference used in the grounds of
`
`unpatentability is directed to providing light with sufficient brightness for purposes
`
`identified in the challenged patent. Petitioners note that in an infringement
`
`proceeding in which the required brightness of the light were at issue, claims
`
`reciting “high brightness light” could be invalid under 35 U.S.C. § 112, second
`
`paragraph for indefiniteness because the patent does not specify how bright the
`
`light must be.
`
`10
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`

`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`
`endoscopic tools.” (Eden Decl. ¶ 37 (Ex. 1203).)
`
`The ’982 patent defines “brightness”4 as “the power radiated by a source of
`
`light per unit surface area onto a unit solid angle.” (’982 patent, 4:46-47 (Ex.
`
`1201).) The brightness of the light produced by a light source “determines” the
`
`ability of a system or operator to “see or measure things [] with adequate
`
`resolution.” (Id. 4:47-51.) Accordingly, the brightness of a light is associated with
`
`the ability to see or measure properties of a surface. (Eden Decl. ¶ 38 (Ex. 1203).)
`
`The ’982 patent recognizes that various uses for high brightness light existed
`
`before the ’982 patent was filed. The patent recognizes in the Background of the
`
`Invention that, “[f]or example, a high brightness light source can be used for
`
`inspection, testing or measuring properties associated with semiconductor wafers
`
`or materials used in the fabrication of wafers (e.g., reticles and photomasks).”
`
`(’982 patent, 1:11-14 (Ex. 1201).) It also identifies light sources that can be used
`
`“as a source of illumination in a lithography system used in the fabrication of
`
`wafers, a microscopy system[], or a photoresist curing system” as further examples
`
`of high brightness light sources. (’982 patent, 1:11-17 (Ex. 1201).) Additionally,
`
`4 Although the ’982 patent uses the term “brightness,” “spectral brightness” is the
`
`more common term in optics and lasers. “Spectral brightness” refers to the optical
`
`power radiated per unit of wavelength (nm) into steradians, the unit of slid angle.
`
`(See Eden Decl. ¶ 38 n.2 (Ex. 1203).)
`
`11
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`

`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`it describes and claims “a wafer inspection tool, a microscope, a metrology tool, a
`
`lithography tool, [and] an endoscopic tool” as tools for which the high brightness
`
`light is produced. (’982 patent, 2:33-38, 10:11-14 (Ex. 1201).) More generally,
`
`the patent acknowledges that the brightness and other parameters of the light “vary
`
`depending upon the application.” (’982 patent, 1:18-20 (Ex. 1201).) (Eden Decl.
`
`¶ 39 (Ex. 1203).)
`
`The Patent Owner has argued that the term “high brightness light” should be
`
`understood as “bright enough to be used for inspection, testing, or measuring
`
`properties associated with semiconductor wafers or materials used in the
`
`fabrication of wafers, or in lithography systems used in the fabrication of wafers,
`
`microscopy systems, or photoresist curing systems—i.e., at least as bright as xenon
`
`or mercury arc lamps,” which is similar to the construction proposed below but
`
`omits some of the applications for high brightness light specifically described in
`
`the ’982 patent. See Second Declaration of Donald K. Smith, Ph.D. in Support of
`
`Energetiq’s Reply Brief in Support of its Motion for Preliminary Injunction, dated
`
`March 17, 2015 (“Second Smith Decl.”) ¶ 20 (Ex. 1211).) (Eden Decl. ¶ 40 (Ex.
`
`1203).)
`
`Therefore, for purposes of this proceeding, the term “high brightness light”
`
`should be interpreted to include “light sufficiently bright to be used for inspection,
`
`testing or measuring properties associated with semiconductor wafers or materials
`
`12
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`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`used in the fabrication of wafers, or as a source of illumination in a lithography
`
`system used in the fabrication of wafers, a microscopy system, a photoresist curing
`
`system, or an endoscopic tool.” (Eden Decl. ¶ 41 (Ex. 1203).)
`
`VII. THE CHALLENGED CLAIMS ARE INVALID
`A. Laser Sustained Plasma Light Sources Were Known Long Before
`the Priority Date of the ’982 Patent
`
`When the application that led to the ’982 patent was filed, there was nothing
`
`new about a light source using an ignition source to generate a plasma in a
`
`chamber and a laser to sustain the plasma to produce high brightness light from the
`
`plasma. This concept had been known and widely used since at least as early as
`
`the 1980s, more than two decades before the application date. For example, in
`
`1983, Gärtner et al. filed a patent application entitled “Radiation source for optical
`
`devices, notably for photolithographic reproduction systems,” which published on
`
`May 3, 1985 as French Patent Application No. 2554302 (“Gärtner,” Ex. 1204).
`
`Gärtner discloses a light source with the same features claimed in the ’982 patent:
`
`(1) a sealed chamber 1 (green); (2) an ignition source – pulsed laser 10 (blue),
`
`which generates a plasma 14; and (3) a laser to produce light – laser 9 (red), which
`
`provides energy to the plasma 14 and produces light 15. (Eden Decl. ¶ 42 (Ex.
`
`1203).)
`
`13
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`

`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`
`’982 patent, Fig. 1 (Ex. 1201)
`
`
`
`
`
`
`
`
`
`Gärtner, Fig. 1 (Ex. 1204)
`
`By the late 1980’s, this concept was already being taught in textbooks. (See
`
`D. Keefer, “Laser-Sustained Plasmas,” Chapter 4, in Radziemski et al., Laser-
`
`Induced Plasmas and Applications, CRC Press (1989) (Ex. 1206).) (Eden Decl.
`
`¶ 43 (Ex. 1203).)
`
`Thus, the purportedly novel features of the ’982 patent are nothing more
`
`than the standard features of laser sustained plasma light sources across several
`
`generations of technology from the 1980’s to the early 2000’s. (Eden Decl. ¶ 44
`
`(Ex. 1203).)
`
`B.
`
`Sustaining a plasma with a laser emitting at least one wavelength
`of electromagnetic energy that is strongly absorbed by the ionized
`medium was well known in the art
`
`There was nothing new about operating a laser that emits at least one
`
`wavelength of electromagnetic energy that is strongly absorbed by the ionized
`
`14
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`

`

`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`medium. Two well understood mechanisms for sustaining plasmas are 1) through
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`elementary collision-radiation processes, which involves supplying energy at or
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`near an absorption line and 2) through excitation of collective motions in plasmas,
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`which does not require the laser energy be at or near an absorption line. (Beterov
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`at 536 (Ex. 1216) (“[A] photoresonance plasma whose properties are determined
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`by elementary collision-radiation processes, is naturally distinguished from a laser
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`plasma, in which the transformation of the energy of the laser radiation into the
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`energy of the plasma particles results from the excitation of collective motions in
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`the plasma”).) In other words, Beterov explains that the laser radiation required to
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`ignite or sustain the plasma can be at or near an atomic transition (the first
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`mechanism) or can operate through other processes that need not have a
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`wavelength that matches an atomic transition (the second mechanism). (Eden
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`Decl. ¶ 45 (Ex. 1203).)
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`Gärtner operates primarily through the second of these mechanisms. In
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`particular, Gärtner’s laser 9 is a CO2 laser. (Gärtner at 5:3-5 (Ex. 1204).) CO2
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`lasers, which generally operate at a wavelength of 10.6 µm, were commonly used
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`during the 1970s and 1980s because they provided high power and were cost-
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`effective at the time. (See, e.g., U.S. Patent No. 4,780,608 to Cross at 5:44-47
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`(“Carbon dioxide lasers have been used since the output therefrom is readily
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`absorbed by plasmas and they are available with very high power in both pulsed
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`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`and cw operating modes.”) (Ex. 1210).) The CO2 laser 9 in Gärtner sustains (and
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`is capable of igniting) the plasma primarily through the process of inverse
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`bremsstrahlung, which is simply the absorption of light (a laser photon) by an
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`electron in the plasma. This absorption of laser light by the “free” electrons in the
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`plasma leads to the “collective oscillations” to which Beterov refers when
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`describing the second mechanism. (Eden Decl. at ¶ 46 (Ex. 1203).)
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`The first mechanism occurs in plasmas referred to by Beterov as
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`“photoresonance” and “quasi-photoresonance” plasmas, where the laser supplies
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`energy at or near an absorption line. For example, Beterov, which was published
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`in June 1988 in the journal “Soviet Physics Uspekhi” and titled “Resonance
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`radiation plasma (photoresonance plasma),” discloses generating a plasma by
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`tuning a laser wavelength to a resonance transition line that is strongly absorbed by
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`a gas or vapor. Beterov states, “One of the methods of creating a plasma involves
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`the action of optical resonance radiation on a gas.” (Beterov at 535 (Ex. 1216).)
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`(Eden Decl. ¶ 47 (Ex. 1203).)
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`Figure 10 of Beterov provides an example of a light source in which the
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`laser is tuned to a resonance transition line that is strongly absorbed. Figure 10
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`shows: 1) a chamber (green); (2) an ignited plasma (yellow); (3) a continuous dye
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`laser (red) tuned to a wavelength that is strongly absorbed to sustain a plasma that
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`emits light. (Beterov at 540, Fig. 10 (Ex. 1216).) (Eden Decl. ¶ 48 (Ex. 1203).)
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`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`
`Beterov, Fig. 10 (Ex. 1216)
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`
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`In this example, the chamber contains sodium (Na) vapor and the continuous
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`dye laser is “tuned in resonance with the 3p-4d transitions (λ = 568.8 or 568.2 nm)
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`of the Na atom.” (Beterov at 540 (Ex. 1216).) Beterov discusses the 3p-4d
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`transition as an example because it was understood to be a transition having
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`wavelength that is strongly absorbed. In particular, a person of skill in the art
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`would understand that the wavelength based on the 3p-4d transition is strongly
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`absorbed because all of the alkali atoms (lithium (Li), sodium (Na), potassium (K),
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`rubidium (Rb), and cesium (Cs)) are what is known in physics as “one electron”
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`atoms and the strengths of alkali atomic transitions are renown as being among the
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`strongest of all atomic lines. Therefore, the laser emitting energy at a wavelength
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`corresponding to the Na 3p-4d atomic transition would be strongly absorbed by the
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`sodium vapor. (Eden Decl. at ¶ 48 (Ex. 1203).)
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`This approach of supplying energy at a wavelength that is strongly absorbed
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`became more feasible with the invention of tunable lasers. Beterov explains that
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`U.S. Patent 7,435,982
`Petition for Inter Partes Review
`the “potentialities of study of photoresonance plasmas, as well as the set of their
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`application, have been expanded by the invention of frequency-tunable lasers.”
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`(Beterov at 535 (Ex. 1216).) (Eden Decl. ¶ 49 (Ex. 1203).)
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`Wolfram, which was granted on February 13, 1990 as U.S. Patent No.
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`4,901,330 and titled “Optically Pumped Laser,” (“Wolfram,” (Ex. 1215)), discloses
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`a further example of operating a laser emitting at least one wavelength of
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`electromagnetic energy that is strongly absorbed by the ionized medium. (Eden
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`Decl. ¶ 50 (Ex. 1203).) Wolfram teaches that lasers “can be tuned for the
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`appropriate output radiation wavelength” such that they provide energy at an
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`absorption peak that is strongly absorbed by the target material, which results in
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`more efficient light emission by the target material. (Wolfram, 4:36-51 (Ex.
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`1215).) Wolfram teaches that the target material can be excited by “the creation of
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`a population inversion through the absorption of light” and that the laser energy
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`provided “must be of a very precise character as within the absorption band of the
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`lasant material. In particular, the pumping radiation must be of a wavelength
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`which is absorbed by the lasant material to produce the required population
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`inversion.” (Wolfram, 1:36-41, 1:45-51 (Ex. 1215).) Specifically, Wolfram
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`discloses a laser that “emits light at a wavelength of about 2 nm or less above the
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`absorption peak at the lasant material 18.” (Wolfram, 4:34-52 (Ex. 1215).) (Eden
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`Decl. ¶ 50 (Ex. 1203).)
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`U.S. Patent 7,435,982
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`By 2004, tunable lasers such as 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 infrared regions (660-1180 nm). Silfvast states, for example, that the
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`output power of the tunable Ti:sapphire laser was “up to 50 W (cw)” and the laser
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`wavelengths are “660-1180 nm.” (Silfvast, at 567 (Ex. 1209).) In other words,
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`lasers were available that could be tuned to wavelengths that are strongly absorbed
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`by xenon and that could provide at least 50 watts of continuous power. (Eden
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`Decl. ¶ 51 (Ex. 1203).)
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`Tunable lasers have several other advantages. For example, they were
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`considerably smaller and more efficient than CO2 lasers. For example,
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`“Commercially available cw CO2 lasers range in power from 6 watts to 10,000
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`watts, and custom lasers are available at even higher powers. Small (2 to 3 feet
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`long) CO2 lasers can produce hundreds of watts of average power at an efficiency
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`of 10%.” (Kelin Kuhn, Laser Engineering, at 385 (1998) (Ex. 1217).) Therefore,
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`even a “small” CO2 laser was 2 to 3 feet in length and these numbers do not
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`include the laser’s power supply. In contrast, rare earth-doped fiber lasers also
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`produced hundreds of watts by 2004, and did so in a much smaller package.
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`Furthermore, since