DOCKET NO.: 0107945.00235US22
`Filed By: Donald 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 IPR2016-00578
`
`
`
`PETITION FOR INTER PARTES REVIEW OF
`U.S. PATENT NO. 7,786,455
`CLAIMS 20, 21, 24
`
`
`
`
`
`
`
`

`
`U.S. Patent 7,786,455
`Petition for Inter Partes Review
`TABLE OF CONTENTS
`
`
`I. 
`
`B. 
`
`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 ’455 PATENT ............................................................ 5 
`A. 
`Summary of the Prosecution History .................................................... 7 
`VI.  CLAIM CONSTRUCTION ............................................................................ 8 
`A. 
`“High brightness light” .......................................................................... 9 
`B. 
`“Large solid angle” .............................................................................. 12 
`VII.  THE CHALLENGED CLAIMS ARE INVALID ......................................... 14 
`A. 
`Laser Sustained Plasma Light Sources Were Known Long
`Before the Priority Date of the ’455 Patent ......................................... 14 
`Using a dichroic mirror to separate light of different
`wavelengths was well known in the art. .............................................. 17 
`VIII.  GROUNDS FOR FINDING THE CHALLENGED CLAIMS INVALID ... 18 
`A.  Ground 1: Claim 20 is unpatentable over Gärtner in view of
`Ershov .................................................................................................. 18 
`(a)  Gärtner and Ershov are each prior art that was not considered by
`the Patent Office during examination ........................................... 19 
`(b)  Claim 20 is obvious by Gärtner in view of Ershov ...................... 21 
`Ground 2: Claim 21 is unpatentable over Gärtner in view of
`Ershov and further in view of Ito ........................................................ 33 
`
`B. 
`
`i
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`

`
`U.S. Patent 7,786,455
`Petition for Inter Partes Review
`(a)  Gärtner, Ershov and Ito are each prior art that was not considered
`by the Patent Office during examination. ..................................... 33 
`(b)  Claim 21 ....................................................................................... 34 
`Ground 3: Claim 24 is unpatentable over Gärtner in view of
`Silverman ............................................................................................. 42 
`(a)  Gärtner and Silverman are each prior art that was not considered
`by the Patent Office during examination. ..................................... 43 
`(b)  Claim 24 ....................................................................................... 43 
`(c)  Reasons to combine ...................................................................... 48 
`IX.  RESPONSE TO ARGUMENTS RAISED BY PATENT OWNER IN ITS
`PRELIMINARY INJUNCTION MOTION .................................................. 51 
`A. 
`Patent Owner’s Arguments Regarding the Content of the Prior
`Art ........................................................................................................ 51 
`(a)  High Brightness Light .................................................................. 51 
`Patent Owner’s Arguments Regarding Objective Indicia of
`Non-Obviousness ................................................................................ 56 
`CONCLUSION .............................................................................................. 58 
`
`
`X. 
`
`
`C. 
`
`B. 
`
`ii
`
`

`
`U.S. Patent 7,786,455
`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. 7,786,455 (“the ’455 patent,” Ex. 1401) is one member of a
`
`patent family of continuation, continuation in part, and divisional applications.
`
`Exhibit 1402 shows the U.S. members of this patent family and the relationships
`
`among them. Petitioners have already filed petitions seeking inter partes review of
`
`the ’455 patent, and of related U.S. Patent Nos. 7,435,982 (“the ’982 patent”);
`
`8,309,943 (“the ’943 patent”); 8,525,138 (“the ’138 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 7,786,455
`Petition for Inter Partes Review
`Pending
`Instituted on all
`challenged claims
`Pending
`
`Petitioners are also filing additional petitions on the ’455, ’982, ’943, ʼ138,
`
`’841, and ’000 patents, as well as on the related U.S. Patent No. 9,185,786 (“the
`
`’786 patent”). Petitioners request that the inter partes reviews of all the ’455, ’982,
`
`’943, ’138, ’841, ’000, and ’786 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 Tech., Inc. v. ASML Netherlands B.V., et al, Civil
`
`Action 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)
`
`Service Information
`
`D.
`Email: Donald R. Steinberg, don.steinberg@wilmerhale.com
`
`Post and Hand Delivery: WilmerHale, 60 State St., Boston, MA 02109
`
`2
`
`

`
`Telephone: 617-526-6453
`
`
`
`U.S. Patent 7,786,455
`Petition for Inter Partes Review
`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 20-21 and 24 of the ’455 patent (“the challenged claims”) and request that
`
`each challenged claim be cancelled.
`
`A. Grounds for Challenge
`This Petition, supported by the declaration of Dr. Howard Milchberg, a
`
`Professor of Physics and Electrical and Computer Engineering at the University of
`
`Maryland in College Park, Maryland (“Milchberg Decl.,” Ex. 1403), 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. § 314(a). As
`
`detailed in the grounds of unpatentability below, the challenged claims are
`
`unpatentable under 35 U.S.C. § 103.
`
`Prior Art Patents and Printed Publications Relied Upon
`
`B.
`Petitioners rely upon the following patents and printed publications:
`
`3
`
`

`
`U.S. Patent 7,786,455
`Petition for Inter Partes Review
`1. French Patent Publication No. FR2554302A1 (with English Translation),
`
`published May 3, 1985 (“Gärtner,” Ex. 1404), and is prior art to the ʼ455 patent
`
`under 35 U.S.C. § 102(b).
`
`2. Japanese Patent Publication No. JPH04-144053A, (with English Translation),
`
`published May 18, 1992 (“Ito,” Ex. 1405), and is prior art to the ʼ455 patent
`
`under 35 U.S.C. § 102(b).
`
`3. U.S. Patent Publication No. 2006/0192152, filed August 31, 2005, published
`
`August 31, 2006 (“Ershov,” Ex. 1416), and is prior art to the ʼ455 patent under
`
`35 U.S.C. §§ 102(a) and/or 102(e).
`
`4. U.S. Patent Publication No. 2004/0183031, filed March 20, 2003, published
`
`September 23, 2004 (“Silverman,” Ex. 1415), and is prior art to the ’455 patent
`
`under 35 U.S.C. § 102(b).
`
` Relief Requested
`
`C.
`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 ’455
`
`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
`
`4
`
`

`
`U.S. Patent 7,786,455
`Petition for Inter Partes Review
`experience with lasers and plasma. (Milchberg Decl. ¶ 21 (Ex. 1403).)
`
`V. OVERVIEW OF THE ’455 PATENT
`The ’455 patent 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 includes a chamber (green), an ignition
`
`source (blue) for igniting a plasma, and a laser (red) for providing energy to the
`
`plasma to produce light. (’455 patent, 4:25-7:34 (Ex. 1401).) (Milchberg Decl.
`
`¶ 22 (Ex. 1303).)
`
`
`
`’455 patent Fig. 1 (Ex. 1401) (Annotated)
`
`The ’455 patent also describes the use of reflectors for reflecting or
`
`transmitting laser energy and plasma light. For example, as illustrated in Figure 5,
`
`below, reflective surface 540 (purple) can direct laser energy to the plasma in the
`
`chamber and direct emitted light towards the output. (’455 patent, 13:10-29 (Ex.
`
`1401).) Additionally, reflector 512 (orange) reflects the laser beam 520 toward the
`
`5
`
`

`
`U.S. Patent 7,786,455
`Petition for Inter Partes Review
`reflective surface 540 (purple) of the chamber and the reflector 512 (orange) is
`
`substantially transparent to plasma light 536. (’455 patent, 13:10-29 (Ex. 1401).)
`
`(Milchberg Decl. ¶ 23 (Ex. 1503).)
`
`’455 patent Fig. 5 (Ex. 1401) (Annotated)
`
`
`
`According to the ’455 patent, prior art light sources relied upon electrodes to
`
`both generate and sustain the plasma, which resulted in wear and contamination.
`
`(’455 patent, 1:28-44 (Ex. 1401).) Thus, a need allegedly arose for a way to
`
`sustain a plasma without relying on an electrical discharge from electrodes. (’455
`
`patent, 1:45-49 (Ex. 1401).) The purported invention involves using a laser to
`
`provide energy to sustain the plasma to produce a “high brightness” light source.
`
`(See, e.g., ’455 patent, 1:57-59 (Ex. 1401).) Additionally, the purported invention
`
`also involves different configurations of reflectors to direct energy and light. (’455
`
`patent, 4:25-7:34 (Ex. 1401).) (Milchberg Decl. ¶ 24 (Ex. 1403).)
`
`6
`
`

`
`U.S. Patent 7,786,455
`Petition for Inter Partes Review
`As discussed below, sustaining a plasma with a laser to produce high
`
`brightness light and using configurations of reflectors to direct energy and light
`
`was well known prior to the earliest claimed priority date of the ’455 patent.
`
`(Milchberg Decl. ¶ 25 (Ex. 1403).) Prior art references, such as Gärtner, disclosed
`
`a laser-sustained plasma light source with the same elements as the ’455 patent: a
`
`chamber, an ignited plasma, a laser, and reflective surfaces. (Milchberg Decl. ¶ 25
`
`(Ex. 1403).)
`
`Furthermore, there was nothing new about using a dichroic mirror to
`
`separate out (a) light from a laser beam, and (b) light emitted from a target
`
`irradiated by the laser. For example, Ito disclosed using a dichroic mirror to
`
`separate out light in this fashion. (Milchberg Decl. ¶ 26 (Ex. 1403).)
`
`A.
`
`Summary of the Prosecution History
`
`The ’455 patent issued from U.S. Patent Appl. No. 11/695,348, filed on
`
`April 2, 2007. On May 4, 2010, all the claims were allowed without a rejection
`
`based on prior art. The Notice of Allowability provided several reasons for
`
`allowance, including a statement that the invention involved igniting a gas within a
`
`chamber with a reflective surface and providing laser energy to the ionized gas in
`
`the chamber to produce a plasma that generates high brightness light. (Notice of
`
`Allowability, dated May 4, 2010, at 3-4 (Ex. 1406).) The ’455 patent issued on
`
`August 31, 2010.
`
`7
`
`

`
`U.S. Patent 7,786,455
`Petition for Inter Partes Review
`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. IPR2015-01279, slip op. at 12 (PTAB Nov.
`
`30, 2015) (Paper 13).) (Milchberg Decl. ¶ 28 (Ex. 1403).)
`
`VI. CLAIM CONSTRUCTION
`A claim in inter partes review is given the “broadest reasonable construction
`
`in light of the specification of the patent in which it appears.” 37 C.F.R. §
`
`42.100(b); see Office Patent Trial Practice Guide, 77 Fed. Reg. 48,756, at 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
`
`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.
`
`8
`
`

`
`U.S. Patent 7,786,455
`Petition for Inter Partes Review
`
`48,764; 48,766-67 (Aug. 14, 2012).
`
`Consistent with this standard, this section proposes, under the broadest
`
`reasonable construction standard, constructions of terms and provides support for
`
`these proposed constructions. Terms not included in this section have their
`
`broadest reasonable meaning in light of the specification as commonly understood
`
`by those of ordinary skill.
`
`Applying the claim construction standard of Phillips v. AWH Corp., 415
`
`F.3d 1303 (Fed. Cir. 2005) would not change the analysis or conclusions covered
`
`in this petition. The prior art teaches each claim limitation under any reasonable
`
`interpretation of the claim terms, and the analysis is not dependent on application
`
`of the "broadest reasonable interpretation" standard. (Milchberg Decl. ¶ 29 (Ex.
`
`1203).)
`
`A.
` “High brightness light”
`The term “high brightness light”1 is recited in claims 19 (from which the
`
`1 The term “light” is sometimes used more narrowly to refer only to visible light.
`
`However, references to “ultraviolet light” in the ’455 patent make clear that the
`
`broader meaning is intended because ultraviolet light has a wavelength shorter than
`
`that of visible light. (See, e.g., ʼ455 patent, 7:33-34; 8:44-45; 10:19-20; 10:48-50;
`
`12:3-5; 12:11-13; 12:44-46; 13:64-14:4; 14:55-57; 17:3-4 (Ex. 1401).) (See
`
`Milchberg Decl. ¶ 30 n.1 (Ex. 1403).)
`
`9
`
`

`
`U.S. Patent 7,786,455
`Petition for Inter Partes Review
`challenged claims depend), 21, and 24. For purposes of this proceeding, the term
`
`“high brightness light”2 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 system, photoresist curing systems, or endoscopic tools.” (Milchberg
`
`Decl. ¶ 30 (Ex. 1403).)
`
`The ’455 patent defines “brightness”3 as “the power radiated by a source of
`
`2 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” would be invalid under 35 U.S.C. § 112, second
`
`paragraph for indefiniteness because the patent does not specify how bright the
`
`light must be. (Milchberg Decl. ¶ 30 n.2 (Ex. 1403).)
`
`3 Although the ’455 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) per steradian, the unit of solid angle.
`
`(Milchberg Decl. ¶ 31 n.3 (Ex. 1403).)
`
`10
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`

`
`U.S. Patent 7,786,455
`Petition for Inter Partes Review
`light per unit surface area into a unit solid angle.” (’455 patent, 8:27-28 (Ex.
`
`1401).) 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.” (’455 patent, 8:28-32 (Ex. 1401).) (Milchberg Decl. ¶ 31 (Ex. 1403).)
`
`The ’455 patent recognizes that high brightness light has been used for
`
`various purposes long before the ’455 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).” (’455 patent, 1:17-21 (Ex. 1401).) 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. (’455 patent, 1:21-25 (Ex.
`
`1401).) Additionally, 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. (’455 patent, 2:46-50, 3:61-64,
`
`10:15-21, 15:8-14 (Ex. 1401).) More generally, the patent acknowledges that the
`
`brightness and other parameters of the light “vary depending upon the application.”
`
`(’455 patent, 1:25-27 (Ex. 1401).) (Milchberg Decl. ¶ 32 (Ex. 1403).)
`
`The Patent Owner has argued that the term “high brightness light” should be
`
`11
`
`

`
`U.S. Patent 7,786,455
`Petition for Inter Partes Review
`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 applications specifically identified in the ’455 patent. (See Second Smith
`
`Declaration ¶ 20 (Ex. 1408).) (Milchberg Decl. ¶ 33 (Ex. 1403).)
`
`Therefore, for purposes of this proceeding, the term “high brightness light”
`
`should be interpreted 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 endoscopic tools.”4 (Milchberg Decl. ¶ 34 (Ex.
`
`1403).)
`
`“Large solid angle”
`
`B.
`The term “large solid angle” is recited in claim 24. For purposes of this
`
`
`4 The proposed construction for the claim term “high brightness light” was adopted
`
`by the Board in the Decision granting Institution of Inter Partes Review for claims
`
`19 and 39-41. (See Case No. IPR2015-01279 (PTAB Nov. 30, 2015) (Paper 13).)
`
`12
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`

`
`U.S. Patent 7,786,455
`Petition for Inter Partes Review
`proceeding, the term “large solid angle”5 should be construed to mean a solid angle
`
`greater than 3 steradians. Like claim 24 of the ’455 patent, claim 12 recites a
`
`“reflective surface of the chamber is adapted to collect the high brightness light
`
`generated by the plasma over a large solid angle.” (’455 patent, 18:34-36, 19:21-
`
`23 (Ex. 1401).) Claims 13 and 14, which depend from claim 12, recite that the
`
`large solid angle “is greater than about 3 steradians” and “is about 5 steradians.”
`
`(’455 patent, 18:37-40 (Ex. 1401).) The ’455 patent provides no further insight
`
`into what constitutes a “large” solid angle. It provides in the specification
`
`examples of solid angles of 0.012 and 0.048 steradians (’455 patent, 16:65-17:27
`
`(Ex. 1401).), as well as of “larger” solid angles of 5 and 6.28 steradians (’455
`
`patent, 17:28-42 (Ex. 1401).) Therefore, the term “large solid angle” should be
`
`construed to mean a solid angle greater than 3 steradians. (Milchberg Decl. ¶ 35
`
`(Ex. 1403).)
`
`
`5 For purposes of this proceeding, it is sufficient to interpret “large solid angle” as
`
`Petitioners explain above. Petitioners note that in an infringement proceeding in
`
`which the required size of the angle were at issue, claims reciting a “large solid
`
`angle” would be invalid under 35 U.S.C. § 112, second paragraph for
`
`indefiniteness because the patent does not specify how large the solid angle must
`
`be. (Milchberg Decl. ¶ 35 n.5 (Ex. 1403).)
`
`13
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`

`
`U.S. Patent 7,786,455
`Petition for Inter Partes Review
`VII. THE CHALLENGED CLAIMS ARE INVALID
`A. Laser Sustained Plasma Light Sources Were Known Long Before
`the Priority Date of the ’455 Patent
`
`When the application that led to the ’455 patent was filed, there was nothing
`
`new about using an ignition source to generate a plasma in a chamber, a laser to
`
`sustain the plasma to produce high brightness light from the plasma, and reflective
`
`surfaces as described and claimed in the ’455 patent. This concept had been
`
`known and widely used since at least as early as the 1980s, more than two decades
`
`before the application date. (Milchberg Decl. ¶ 35 (Ex. 1403).) 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
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`May 3, 1985 as French Patent Application No. 2554302. (“Gärtner,” Ex. 1404.)
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`As shown in Fig. 1, reproduced below adjacent to Fig. 1 of the ’455 patent, Gärtner
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`disclosed a light source with the same features claimed in the ’455 patent: (1) a
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`chamber 1 (green); (2) an ignition source – pulsed laser 10 (blue), which ionizes a
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`gas; (3) a laser to produce plasma light – laser 9 (red), which provides energy to
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`the plasma 14 and produces light 15; and (4) a reflective surface 12 (purple). Fig.
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`1 of the ’455 patent is also reproduced below. (Gärtner at 4:31-5:9 (Ex. 1404).)
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`(Milchberg Decl. ¶ 36 (Ex. 1403).)
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`14
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`U.S. Patent 7,786,455
`Petition for Inter Partes Review
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`’455 patent Fig. 1 (Ex. 1401) (Annotated)
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`Gärtner, Fig. 1 (Ex. 1404)
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`
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`(Annotated)
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`In addition, on August 31, 2005, Ershov et al. filed U.S. Patent Application
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`No. 2006/0192152, entitled “LPP EUV Light Source Drive Laser System.”
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`(“Ershov,” Ex. 1416). As shown in Figs. 1 and 12, reproduced below, Ershov
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`discloses a light source with features similar to the ’455 patent: (1) a chamber
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`(represented below in green); (2) an ignited plasma at focal point 28 (blue); (3) a
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`laser for providing energy to the plasma – laser light 342 (red); and (4) reflective
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`surface 30 for reflecting laser energy and plasma light (purple). (See Ershov, ¶¶
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`22-23, Fig. 1 (Ex. 1416).) (Milchberg Decl. ¶ 37 (Ex. 1403).)
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`15
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`U.S. Patent 7,786,455
`Petition for Inter Partes Review
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`Ershov, Fig. 1 (Ex. 1416) (Annotated)
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`
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`Ershov, Fig. 12 (Ex. 1416) (Annotated)
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`16
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`U.S. Patent 7,786,455
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`B. Using a dichroic mirror to separate light of different wavelengths
`was well known in the art.
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`Dichroic mirrors are standard optical elements that have been part of the
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`skilled person’s toolkit for building optical systems for decades. (See, e.g., IEEE
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`Standard Dictionary of Electrical and Electronic Terms (1988) (“Dichroic mirror
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`(fiber optics). A mirror designed to reflect light selectively according to
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`wavelength.”) (Ex. 1410).) Dichroic mirrors generally use the known principle of
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`thin film interference, which uses alternating layers of optical coatings with
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`different refractive indexes built upon a transparent substrate, such as glass or
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`quartz. (See, e.g., James Ingle and Stanley Crouch, “Spectrochemical Analysis,” at
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`59 Prentice Hall (1998) (“Another type of beam splitter is a wavelength-selective
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`beam splitter or dichroic mirror. Such mirrors are made from multilayer,
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`nonabsorbing films.”) (Ex. 1411).) One of skill in the art would have known that
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`by controlling the thickness and the number of layers, the frequency (wavelength)
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`of the passband of the filter can be tuned and made as wide or narrow as desired.
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`(Milchberg Decl. ¶ 38 (Ex. 1403).)
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`Furthermore, one of skill in the art would have understood how to use a
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`dichroic mirror that selectively reflects at least one wavelength of light in order to
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`separate out (i) light from a laser beam from (ii) light emitted by a target irradiated
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`by the laser beam. For example Ito describes using a dichroic mirror that reflects a
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`laser beam having a fundamental frequency of 1064 nm onto a target, which causes
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`17
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`U.S. Patent 7,786,455
`Petition for Inter Partes Review
`the target to generate light. (Ito at 3 (Ex. 1405).) The light generated from the
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`target is then passed back to the dichroic mirror. Since the dichroic mirror in this
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`example only reflects light with wavelengths around 1064 nm, the generated light
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`passes through the dichroic mirror without being reflected back toward the laser.
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`(Id.) (Milchberg Decl. ¶ 39 (Ex. 1403).)
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`Thus, the purportedly novel features of the ’455 patent are, in actuality,
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`standard features of laser sustained plasma light sources described in prior art from
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`the 1980s onward. (Milchberg Decl. ¶ 40 (Ex. 1103).)
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`VIII. GROUNDS FOR FINDING THE CHALLENGED CLAIMS INVALID
`Pursuant to Rule 42.104(b)(4)-(5), specific grounds for finding the
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`challenged claims invalid are identified below and discussed in the Milchberg
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`Declaration (Ex. 1403). These grounds demonstrate in detail that claims 20, 21,
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`and 24 are invalid under 35 U.S.C. § 103. (Milchberg Decl. ¶ 41 (Ex. 1403).)
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`A. Ground 1: Claim 20 is unpatentable over Gärtner in view of
`Ershov
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`Claim 20 relates to a method for producing light by ionizing a gas within a
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`chamber comprising a reflective surface and by producing a plasma that generates
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`a high brightness light. Claim 20 is obvious over Gärtner in view of Ershov, as
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`outlined in the chart below. (Milchberg Decl. ¶ 42 (Ex. 1403).)
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`18
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`U.S. Patent 7,786,455
`Petition for Inter Partes Review
`
`’455 Patent Claim 20
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`Prior Art
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`[19p] A method of producing light, comprising:
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`Gärtner, 1:1-4, Figs. 1-4
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`[19a] ionizing with an ignition source a gas within
`a chamber comprising a reflective surface; and
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`Gärtner, 3:20, 4:32, 5:15-16,
`6:9-10, Figs. 1-4
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`Gärtner, 1:1-2, 3:22-24, 5:5-9,
`Figs. 1-4
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`Ershov, ¶ 0051, Fig. 12
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`[19b] providing laser energy to the ionized gas in
`the chamber to produce a plasma that generates a
`high brightness light.
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`[20] The method of claim 19, comprising directing
`the laser energy comprising a first set of
`wavelengths of electromagnetic energy toward the
`reflector, the reflector reflects at least a portion of
`the first wavelengths of electromagnetic energy
`toward the reflective surface of the chamber, the
`reflective surface directs a portion of the first set of
`wavelengths of electromagnetic energy toward the
`plasma.
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`(a) Gärtner and Ershov are each prior art that was not considered by
`the Patent Office during examination
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`Gärtner is prior art under 35 U.S.C. § 102(b) because it published more than
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`a year before the earliest claimed priority date for the ’455 patent, which is March
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`31, 2006. Gärtner was not considered by the Examiner during prosecution of the
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`’455 patent. (Milchberg Decl. ¶ 43 (Ex. 1403).)
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`19
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`U.S. Patent 7,786,455
`Petition for Inter Partes Review
`Ershov is prior art under 35 U.S.C. §§ 102(a)6 and/or 102(e)7 because it was
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`filed August 31, 2005 and published August 31, 2006. Ershov was not considered
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`6 The reflector and reflective surface claimed in challenged claims 20-21 of the
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`’455 patent was first arguably disclosed in the ’455 patent. (See, e.g., ʼ455 patent,
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`13:10-29 (Ex. 1401).) The “reflector reflects at least a portion of the first
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`wavelengths of electromagnetic energy toward the reflective surface of the
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`chamber, [and] the reflective surface directs a portion of the first set of
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`wavelengths of electromagnetic energy toward the plasma” does not appear at all
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`in the ʼ982 patent, the parent of the ʼ455 patent. (See generally ʼ982 patent (Ex.
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`1413).) Thus, challenged claims 20-21 of the ’455 patent can only properly
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`establish a priority date to the ’455 patent filing date of April 2, 2007. Because
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`Ershov was published before April 2, 2007, it is therefore prior art under 35 U.S.C.
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`§ 102(a) to challenged claims 20-21. (Milchberg Decl. ¶ 44, n. 6 (Ex. 1403).)
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`7 The portions of Ershov relied upon in this Petition are supported by Ershov’s
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`parent application, U.S. Patent Application No. 11/174,299 (“the ʼ299
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`application”), which was filed on June 29, 2005 (Ex. 1414). See, e.g., ʼ299
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`application, 15:3-16 (corresponding to Ershov, ¶ [0051]), 1:16-17 (corresponding
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`to Ershov, ¶ [0002]), 10:26-11:20 (corresponding to Ershov, ¶ [0041]), 5:19-6:8
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`(corresponding to Ershov, ¶ [0023]) (Ex. 1414). Accordingly, Ershov is entitled to
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`a prior art date of June 29, 2005.
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`20
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`U.S. Patent 7,786,455
`Petition for Inter Partes Review
`by the Examiner during prosecution of the ’455 patent. (Milchberg Decl. ¶ 44 (Ex.
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`1403).)
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`(b) Claim 20 is obvious by Gärtner in view of Ershov
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`Claim 20 of the ’455 paten