DOCKET NO.: 0107495.00235US14
`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 IPR2016-00565
`
`
`
`PETITION FOR INTER PARTES REVIEW OF
`U.S. PATENT NO. 8,525,138
`CLAIMS 6, 7, AND 10
`
`

`
`U.S. Patent 8,525,138
`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 ’138 PATENT ............................................................ 5 
`A. 
`Summary of the Prosecution History .................................................... 9 
`VI.  CLAIM CONSTRUCTION .......................................................................... 11 
`A. 
`“Light source” ..................................................................................... 12 
`VII.  THE CHALLENGED CLAIMS ARE INVALID ......................................... 15 
`A. 
`Laser-Sustained Light Sources Were Known Long Before the
`Priority Date of the ’138 Patent........................................................... 15 
`Sustaining a plasma with a laser operating within 10 nm of a
`strong absorption line was well known in the art. ............................... 16 
`VIII.  GROUNDS FOR FINDING THE CHALLENGED CLAIMS INVALID ... 22 
`A.  Ground 1: Claims 6 and 7 Are Unpatentable Over Gärtner in
`View of Beterov .................................................................................. 23 
`(a)  Gärtner and Beterov are each prior art that was not considered by
`the Patent Office during examination. .......................................... 23 
`(b)  Independent Claim 1 from which Claims 6 and 7 Depend is
`Unpatentable Over Gärtner in View of Beterov .......................... 24 
`(c)  Dependent Claims 6 and 7 are Unpatentable over Gärtner in view
`of Beterov ..................................................................................... 38 
`
`B. 
`
`i
`
`

`
`B. 
`
`C. 
`
`U.S. Patent 8,525,138
`Petition for Inter Partes Review
`Ground 2: Claims 6 and 7 Are Unpatentable Over Gärtner in
`View of Wolfram ................................................................................. 40 
`(a)  Gärtner and Wolfram are each prior art that was not considered
`by the Patent Office during examination. ..................................... 40 
`(b)  Independent Claim 1 from which claims 6 and 7 depend is
`Unpatentable Over Gärtner in View of Wolfram ......................... 41 
`(c)  Dependent Claims 6 and 7 are Unpatentable over Gärtner in view
`of Wolfram ................................................................................... 44 
`Ground 3: Claim 10 is obvious over Gärtner in view of Beterov
`and Keefer ........................................................................................... 45 
`(a)  Gärtner, Beterov, and Keefer are each prior art that was not
`considered by the Patent Office during examination. .................. 45 
`(b)  Claim 10 is Unpatentable over Gärtner in view of Beterov and
`Keefer ........................................................................................... 46 
`(c)  Reasons to Combine ..................................................................... 49 
`D.  Ground 4: Claim 10 is obvious over Gärtner in view of
`Wolfram and Keefer ............................................................................ 53 
`(a)  Gärtner and Wolfram are each prior art that was not considered
`by the Patent Office during examination. ..................................... 54 
`(b)  Claim 10 is Unpatentable over Gärtner in view of Wolfram and
`Keefer ........................................................................................... 54 
`(c)  Reasons to Combine ..................................................................... 55 
`IX.  RESPONSE TO ARGUMENTS RAISED BY PATENT OWNER IN ITS
`PRELIMINARY INJUNCTION MOTION .................................................. 55 
`A. 
`Patent Owner’s Arguments Regarding the Content of the Prior
`Art ........................................................................................................ 55 
`Patent Owner’s Arguments Regarding Objective Indicia of
`Non-Obviousness ................................................................................ 57 
`CONCLUSION .............................................................................................. 59 
`
`X. 
`
`B. 
`
`ii
`
`

`
`U.S. Patent 8,525,138
`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. 8,525,138 (“the ’138 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 have already filed a petition seeking inter partes review of the ’138
`
`patent and of related U.S. Patent Nos. 7,435,982 (“the ’982 patent”); 7,786,455
`
`(“the ’455 patent”); 8,309,943 (“the ’943 patent”); 8,969,841 (“the ’841 patent”);
`
`and 9,048,000 (“the ’000 patent”), as summarized below:
`
`IPR No.
`
`Challenged Claims
`
`Status
`
`Patent
`No.
`7,435,982
`
`IPR2015-01300
`IPR2015-01303
`
`1, 3-4, 10, 16, 21, 24-
`27, 30, 31, 34, 37, 42-
`43, 49, 55, 61-64, 67,
`68, 71, 72, 74, and 78
`23 and 60
`
`7,435,982
`
`IPR2015-01377
`
`7,786,455
`
`IPR2015-01279
`
`19, 39-41
`
`8,309,943
`
`IPR2015-01277
`
`1, 3, 13, and 16
`
`8,525,138
`
`IPR2015-01368
`
`1-5
`
`8,969,841
`
`IPR2015-01362
`
`1, 2, 3, and 7
`
`1
`
`Instituted on all
`challenged claims
`
`Instituted on all
`challenged claims
`Instituted on all
`challenged claims
`Instituted on all
`challenged claims
`Instituted on all
`challenged claims
`Instituted on all
`challenged claims
`
`

`
`8,969,841
`9,048,000
`
`IPR2016-00127
`IPR2015-01375
`
`10, 13, 14
`1, 15, and 18
`
`9,048,000
`
`
`IPR2016-00126
`
`7-10
`
`U.S. Patent 8,525,138
`Petition for Inter Partes Review
`Pending
`Instituted on all
`challenged claims
`Pending
`
`Petitioners are also filing additional petitions on the ʼ138, ’982, ’455, ’943,
`
`’841, and ’000 patents, as well as on the related U.S. Patent No. 9,185,786 (“the
`
`’5786 patent”)1. Petitioners request that the inter partes reviews of the ʼ138, ’982,
`
`’455, ’943, ’841, ’000, and ’5786 patents 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 Technology, 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. No. 337-TA-983.
`
`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)
`
`D.
`Service Information
`
`1 The use of the ’5786 shortened form is to distinguish this patent from another
`
`Energetiq patent in the family, U.S. Patent No. 7,989,786 (“the ’9786 patent”).
`
`2
`
`

`
`U.S. Patent 8,525,138
`Petition for Inter Partes Review
`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 6, 7, and 10 of the ’138 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 under 35 U.S.C. § 103 for the reasons cited in this petition.
`
`See 35 U.S.C. § 314(a).
`
`Prior Art Patents and Printed Publications Relied Upon
`
`B.
`Petitioners rely upon the following patents and printed publications:
`
`3
`
`

`
`U.S. Patent 8,525,138
`Petition for Inter Partes Review
`1. French Patent Publication No. FR2554302A1, published May 3, 1985 with
`
`English Translation (“Gärtner,” Ex. 1104), which is prior art 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. 1106), which is prior art
`
`under 35 U.S.C. § 102(a) and (b).
`
`3. U.S. Patent No. 4,901,330, filed July 20, 1988 (“Wolfram,” Ex. 1117), issued
`
`Feb. 13, 1990, which is prior art under 35 U.S.C. § 102(a) and (b).
`
`4. D. R. Keefer, “Laser-Sustained Plasmas,” Laser-Induced Plasmas and
`
`Applications, Marcel Dekker, edited by Radiemski et al, p. 169-206 (1989)
`
`(“Keefer”), which is prior art 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 skill in the art at the time of the alleged invention of the ’138
`
`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. ¶ 25 (Ex. 1103).)
`
`4
`
`

`
`U.S. Patent 8,525,138
`Petition for Inter Partes Review
`
`V. OVERVIEW OF THE ’138 PATENT
`The ’138 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, shown below, the light source claimed in the ’138 patent
`
`includes a pressurized chamber (green) containing gas, an ignition source (blue)
`
`for igniting a plasma, and a laser (red) for providing energy to the plasma (yellow)
`
`to produce light. (’138 patent, claim 1 (Ex. 1101).) (Eden Decl. ¶ 26 (Ex. 1103).)
`
`
`
`’138 Patent, Fig. 1 (Annotated)
`
`According to the ’138 patent, prior products relied upon the electrodes used
`
`for ignition to also sustain the plasma, which resulted in wear and contamination.
`
`(’138 patent, 1:33-49 (Ex. 1101).) Thus, a need allegedly arose for a way to
`
`sustain plasma without relying on an electrical discharge. (Id. at 1:50-54 (Eden
`
`Decl. ¶ 27 (Ex. 1103).)
`
`With respect to igniting the plasma, the specification of the ’138 patent
`
`5
`
`

`
`U.S. Patent 8,525,138
`Petition for Inter Partes Review
`states that the “ignition source can be or can include electrodes, an ultraviolet
`
`ignition source, a capacitive ignition source, an inductive ignition source, an RF
`
`ignition source, a microwave ignition source, a flash lamp, a pulsed laser, or a
`
`pulsed lamp.” (’138 patent, 2:48-51 (Ex. 1101).) The claims were limited by
`
`amendment to embodiments in which the ignition source comprises electrodes.
`
`(Infra V.) However, the specification does not identify any purported advantages
`
`of electrodes as compared with other ignition sources, nor does the patent identify
`
`anything inventive about using electrodes as an ignition source as compared with
`
`other types of ignition sources. (Eden Decl. ¶ 28 (Ex. 1103).)
`
`The alleged invention involves using a laser to provide energy to sustain the
`
`plasma for a light source. The ’138 patent is a continuation-in-part that adds the
`
`requirement that the laser be configured to operate at a wavelength within 10 nm of
`
`a “strong absorption line.” (’138 patent, 10:47-60 (Ex. 1101).) The ’138 patent
`
`does not define the term “strong absorption line.”2 Rather, it identifies “980 nm,
`
`895 nm, 882 nm, or 823 nm” as examples of strong absorption lines. (Id. at 34:23-
`
`25.) Table 1 below shows the 823 nm (8232 Å), 882 nm (8819 Å), and 980 nm
`
`2 Petitioners note that in an infringement proceeding in which the required strength
`
`of the absorption line were at issue, claims reciting “strong absorption line” would
`
`be invalid under 35 U.S.C. § 112, second paragraph for indefiniteness because the
`
`patent does not specify how strong the absorption must be.
`
`6
`
`

`
`U.S. Patent 8,525,138
`Petition for Inter Partes Review
`(9800 Å) absorption lines of xenon, which the ’138 patent identifies as strong
`
`absorption lines. The 992 nm line is also a strong absorption line of xenon because
`
`it is listed in Table 1 of the ’138 patent with a higher absorption than either the 823
`
`or 980 lines. (Id. at Table 1.) As noted in the table, these measurements of
`
`absorption lines of xenon were published by Lothar Klein in 1968. (See Lothar
`
`Klein, “Measurements of Spectral Emission and Absorption of a High Pressure
`
`Xenon Arc in the Stationary and the Flashed Modes,” Applied Optics, Vol. 7, No.
`
`4, 677, 683 (1968) (Ex. 1122).) (Eden Decl. ¶ 29 (Ex. 1103).)
`
`
`
`The ’138 patent notes that the strong absorption lines at 980 nm and 882 nm
`
`in xenon are based on transitions between the 6s energy levels and the 6p energy
`
`levels. (’138 patent, 35:28-32 (Ex. 1101).) The other “strong absorption lines” of
`
`xenon identified in Table 1 (823 nm and 992 nm) are also based on transitions
`
`7
`
`

`
`U.S. Patent 8,525,138
`Petition for Inter Partes Review
`from the 6s energy levels to the 6p energy levels. (See, e.g., E. B. Saloman,
`
`“Energy Levels and Observed Spectral Lines of Xenon, XeI through XeLIV,” J.
`
`Phys. Chem. Ref. Data, Vol. 33, No. 3 (2004) at 789-90 (Ex. 1120).) A person of
`
`skill in the art would understand that an atomic transition from the 6s energy levels
`
`to the 6p energy levels of a xenon atom involves moving an electron of the xenon
`
`atom from one of the lowest two excited states of the atom to the third lowest
`
`group of excited states. (Eden Decl. ¶ 30 (Ex. 1103).)
`
`As discussed below, sustaining a plasma with a laser to produce light was
`
`not new at the time of the alleged invention of the ’138 patent. Multiple prior art
`
`references, including Gärtner, Beterov, and Wolfram disclosed laser-sustained
`
`plasma light sources with the same elements as the ’138 patent: a chamber, an
`
`ignited plasma, and a laser providing energy to a plasma to produce light. (Eden
`
`Decl. ¶ 31 (Ex. 1103).)
`
`Additionally, there was nothing new or inventive about operating the laser at
`
`a wavelength near a strong absorption line. For example, Beterov disclosed tuning
`
`a laser onto or near a wavelength corresponding to a strong absorption line of a
`
`gas. Similarly, Wolfram disclosed tuning a laser to a wavelength within 2 nm of a
`
`strong absorption line of the peak of an active medium or lasant material such as
`
`ions of chromium, titanium, or one of the rare earth elements. (Eden Decl. ¶ 32
`
`(Ex. 1103).)
`
`8
`
`

`
`U.S. Patent 8,525,138
`Petition for Inter Partes Review
`Summary of the Prosecution History
`
`A.
`
`The ’138 patent issued from U.S. Patent Appl. No. 13/024,027, filed on
`
`February 9, 2011. The ’138 patent 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.
`
`On July 10, 2012, the PTO issued an office action in which the claims were
`
`rejected. Claim 1 was rejected under 35 U.S.C. § 112, second paragraph, as being
`
`indefinite because the term “high” (in the phrase “high brightness light”) was a
`
`relative term and not defined. (Office Action, dated July 10, 2012, at 2 (Ex.
`
`1109).) Claims 1-8 were rejected under 35 U.S.C. § 102(b) as being anticipated by
`
`Cheymol U.S. Patent Application No. 2006/039435 (“Cheymol”) and Kusunose
`
`U.S. Patent Application No. 2002/0080834 (“Kusunose”). (Id. at 2-5).
`
`On November 8, 2012, the applicant submitted a response. In response to
`
`the 35 U.S.C. § 112 rejection, the applicant argued that “high” was not indefinite
`
`based on examples in the specification. (Response to Non-Final Office Action,
`
`dated Nov. 8, 2012, at 2-3 (Ex. 1110).) In response to the 35 U.S.C. § 102
`
`rejections, applicant tried unsuccessfully to distinguish Cheymol and Kusunose
`
`based on their use of an extreme ultraviolet light source, among other purported
`
`distinctions. (Id. at 3-10.)
`
`On December 12, 2012, the PTO issued a final office action in which the
`
`9
`
`

`
`U.S. Patent 8,525,138
`Petition for Inter Partes Review
`Examiner maintained the 35 U.S.C § 112 rejection, stating that “there is no explicit
`
`definition of how bright is a high brightness light source.” (Office Action
`
`Summary, dated Dec. 12, 2012, at 2 (Ex. 1111).) The Examiner also maintained
`
`the 35 U.S.C. § 102 rejections in light of Cheymol and Kusunose, noting that there
`
`was no reason why an extreme ultraviolet light could not be a high brightness light
`
`and that both references disclosed ignition sources. (Id. at 4-7).
`
`On April 12, 2013, the applicant filed an amendment in which claim 1 was
`
`amended, the other claims were withdrawn, and new claims were added.
`
`(Amendment After Final Office Action, dated April 12, 2013, at 2 (Ex. 1112).)
`
`The applicant removed the high brightness light language. The applicant also
`
`added language requiring a laser at a wavelength within 10 nm of a strong
`
`absorption line for producing a substantially continuous, plasma-generated light,
`
`as well as the chamber being pressurized, and an ignition source comprising
`
`electrodes. Amended claim 1 is shown below:
`
`(Id. at 2). The applicant then sought to distinguish the newly amended claims from
`
`
`
`10
`
`

`
`U.S. Patent 8,525,138
`Petition for Inter Partes Review
`
`the prior art. (Id. at 7-9).
`
`On May 6, 2013, the newly amended claims were allowed. The Notice of
`
`Allowance stated that the prior art did not disclose a continuously sustained plasma
`
`and a wavelength within 10 nm of a strong absorption line. (Notice of
`
`Allowability dated May 6, 2013, at 4-5 (Ex. 1113).) The Examiner Initiated
`
`Interview Summary also noted that the claims were allowed after removal of the
`
`“high brightness” light language, to overcome the 35 U.S.C. § 112 rejection.
`
`(Examiner-Initiated Interview Summary, dated April 29, 2013 (Ex. 1125).) The
`
`’138 patent issued on September 3, 2013 (’138 patent (Ex. 1101).)
`
`The independent claim features identified in the Notice of Allowability as
`
`missing from the prior art 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. IPR2015-01368 at 11 (PTAB Nov. 30,
`
`2015) (Paper 11) (instituting on claims including independent claim 1).)
`
`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
`
`11
`
`

`
`U.S. Patent 8,525,138
`Petition for Inter Partes Review
`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.
`
`48,764, 48,766-67 (Aug. 14, 2012).
`
`Consistent with this standard, this section proposes, under the broadest
`
`reasonable construction standard, constructions of terms that lack a definition in
`
`the specification 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. ¶ 40 (Ex. 1103).)
`
`“Light source”
`
`A.
`“Light source” should be construed to mean “a source of 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 same patent. (Case No.
`
`12
`
`

`
`U.S. Patent 8,525,138
`Petition for Inter Partes Review
`IPR2015-01368 at 5 (PTAB Nov. 30, 2015) (Paper 11).) (Eden Decl. ¶ 41 (Ex.
`
`1103).)
`
`The ordinary and customary meaning of “light source”3 is 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 1,000 µm) regions of the spectrum. (See, e.g., William T.
`
`Silfvast, Laser Fundamentals, at 4 (2d ed. 2003) (“Silfvast”) (Ex. 1108).) The
`
`Patent Owner publishes a data sheet which is consistent with the ordinary and
`
`customary meaning in that it includes extreme ultraviolet within the meaning of
`
`“light source.” (See, e.g., EQ-10M Data Sheet (describing Energetiq’s EQ-10
`
`“EUV [Extreme Ultraviolet] Light Source” product operating at 13.5 nm, which is
`
`in the ultraviolet range) (Ex. 1107).) (Eden Decl. ¶ 42 (Ex. 1103).)
`
`Consistent with the ordinary and customary meaning of “light source,” the
`
`’138 patent states that parameters such as the wavelength of the light from a light
`
`source vary depending upon the application. (’138 patent, 1:30-32 (Ex. 1101).)
`
`3 The term “light” is sometimes used more narrowly to refer only to visible light.
`
`However, references to “ultraviolet light” in the ’138 patent make clear that the
`
`broader meaning is intended. (See, e.g., ʼ138 patent, 7:40-43; 17:2; 18:25, 32;
`
`21:7; 23:22; 26:27 (Ex. 1101).) (See Eden Decl. ¶ 42 n.2 (Ex. 1103).)
`
`13
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`

`
`U.S. Patent 8,525,138
`Petition for Inter Partes Review
`The specification describes “ultraviolet light” as an example of the type of light
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`that can be generated: “In some embodiments, the high brightness light 636
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`includes ultraviolet light.” (’138 patent, 20:20-21 (Ex. 1101); see also id. at 17:1-4
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`(discussing the ultraviolet light 136 generated by the plasma 132 of the light
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`source).) (Eden Decl. ¶ 43 (Ex. 1103).)
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`Notably, during prosecution, the Examiner concluded that high brightness
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`light includes extreme ultraviolet (EUV) light. (Office Action Summary, dated
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`December 12, 2012, at 2 (“[A]pplicant has failed to distinguish in either the claims,
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`or in the specification (for the reasons stated above) that EUV is not a high
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`brightness light source.”) (Ex. 1111).) (Eden Decl. ¶ 44 (Ex. 1103).)
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`Therefore, the term “light source” should be construed to mean “a source of
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`electromagnetic radiation in the ultraviolet (“UV”), extreme UV, vacuum UV,
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`visible, near infrared, middle infrared, or far infrared regions of the spectrum,
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`having wavelengths within the range of 10 nm to 1,000 μm.”4 (Eden Decl. ¶ 45
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`(Ex. 1103).)
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`4 The construction for the claim term “light source” was adopted by the Board in
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`the Decision granting Institution of Inter Partes Review for claims 1-5 of the ‘138
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`patent. (Case No. IPR2015-01368 at 5 (PTAB Nov. 30, 2015) (Paper 11).) This
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`construction is equivalent to the Petitioner’s proposed construction for the term
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`“light source” in that proceeding.
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`U.S. Patent 8,525,138
`Petition for Inter Partes Review
`VII. THE CHALLENGED CLAIMS ARE INVALID
`A. Laser-Sustained Light Sources Were Known Long Before the
`Priority Date of the ’138 Patent
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`The concept of using a laser to sustain a plasma for a light source had been
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`known at least as early as the 1980’s, several decades before the application date.
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`(See Eden Decl. ¶ 46 (Ex. 1103).)
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`For example, in 1983, Gärtner filed a patent application entitled “Radiation
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`source for optical devices, notably for photolithographic reproduction systems,”
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`which published on May 3, 1985 as French Patent Application No. 2554302.
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`(“Gärtner,” Ex. 1104.) As shown in Fig. 1, reproduced below, Gärtner disclosed a
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`light source with the same features claimed in the ’138 patent: (1) a chamber 1
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`(green); (2) an ignition source – pulsed laser 10 (blue), which generates a plasma
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`14 (yellow); and (3) a laser to produce light – laser 9 (red), which provides energy
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`to the plasma 14 and produces light 15. (Id. at 4:31-5:9.) (Eden Decl. ¶ 47 (Ex.
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`1103).)
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`15
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`U.S. Patent 8,525,138
`Petition for Inter Partes Review
`
`Gärtner, Fig. 1 (Annotated) (Ex. 1104)
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`B.
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`Sustaining a plasma with a laser operating within 10 nm of a
`strong absorption line was well known in the art.
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`There was nothing new or inventive about operating a laser within 10 nm of
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`a strong absorption line. Two well understood mechanisms for sustaining plasmas
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`with an external optical source such as a laser are: 1) resonant or near-resonant
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`excitation of the plasma, which involves supplying optical energy at a wavelength
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`on or near an absorption line, and 2) excitation of collective motions in plasmas
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`(such as the absorption of laser light by inverse bremsstrahlung), which does not
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`require the laser energy be at or near an absorption line. (Beterov, 536 (“[A]
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`photoresonance plasma whose properties are determined by elementary collision-
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`radiation processes, is naturally distinguish[able] from a laser plasma, in which the
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`transformation of the energy of the laser radiation into the energy of plasma
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`U.S. Patent 8,525,138
`Petition for Inter Partes Review
`particles results from the excitation of collective motions in the plasma”) (Ex.
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`1106).) In other words, Beterov explains that the laser radiation required to ignite
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`or sustain the plasma can have a wavelength at or near an atomic transition (the
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`first mechanism); however, the laser can also drive other processes that do not
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`require a wavelength that matches an atomic transition (the second mechanism).
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`(Eden Decl. ¶ 48 (Ex. 1103).)
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`Gärtner operates primarily through the second of these mechanisms. The
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`CO2 laser 9 in Gärtner sustains (and is capable of igniting) the plasma primarily
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`through the process of inverse bremsstrahlung, which is simply the absorption of
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`light (a laser photon) by an electron in the plasma. This absorption of laser light by
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`the “free” electrons in the plasma leads to the “collective oscillations” to which
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`Beterov refers when describing the second mechanism. (Eden Decl. ¶ 49 (Ex.
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`1103).)
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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 strong absorption line of a gas or vapor. Beterov
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`states, “One of the methods of creating a plasma involves the action of optical
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`U.S. Patent 8,525,138
`Petition for Inter Partes Review
`resonance radiation on a gas.” (Beterov, 535 (Ex. 1106).) (Eden Decl. ¶ 50 (Ex.
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`1103).)
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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 strong absorption line. Figure 10 shows: 1) a chamber (green);
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`2) an ignited plasma (yellow); and 3) a continuous dye laser (red) tuned to a strong
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`absorption line of the plasma to sustain a plasma that emits light. (Beterov, 540,
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`Fig. 10 (Ex. 1106).) (Eden Decl. ¶ 51 (Ex. 1103).)
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`Beterov, Fig. 10 (Ex. 1106)
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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, 540 (Ex. 1106).) A person of skill in the art would
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`understand that the absorption line based on the 3p-4d transition is a “strong
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`absorption line” because all of the alkali atoms (lithium (Li), sodium (Na),
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`potassium (K), rubidium (Rb), and cesium (Cs)) are “one electron” atoms and the
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`strengths of alkali atomic transitions are known to be among the strongest of all
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`atomic lines. Therefore, the Na 3p-4d atomic transition would absorb at least as
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`U.S. Patent 8,525,138
`Petition for Inter Partes Review
`strongly as the ’138 patent’s exemplary strong absorption lines of xenon which are
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`based on 6s to 6p transitions. (Eden Decl. ¶ 52 (Ex. 1103).)
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`This approach of supplying energy to a plasma at a laser wavelength that
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`coincides with, or is near, a strong absorption line became more feasible with the
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`commercial development of tunable lasers. Beterov explains that the
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`“potentialities of study of photoresonance plasmas, as well as the set of their
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`applications, have been expanded by the invention of frequency-tunable lasers.”
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`(Beterov, 535 (Ex. 1106).) (Eden Decl. ¶ 53 (Ex. 1103).)
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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,” discloses a further example of
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`operating a laser within 10 nm of a strong absorption line of a target material.
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`Wolfram teaches that the lasers “can be tuned for the appropriate output radiation
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`wavelength” such that they provide energy at the absorption peak of the target
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`material, which results in more efficient light emission by the target material.
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`(Wolfram, 4:39-40 (Ex. 1117).) Wolfram teaches that the target material can be
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`excited by a laser, resulting in “the creation of a population inversion through the
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`absorption of light,” and that the laser energy provided “must be of a very precise
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`character as within the absorption band of the lasant material. In particular, the
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`pumping radiation must be of a wavelength which is absorbed by the lasant
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`material to produce the required populatio