UNITED STATES PATENT AND TRADEMARK OFFICE
`
`__________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`__________
`
`CARL ZEISS SMT GMBH
`Petitioner
`
`v.
`
`NIKON CORPORATION
`Patent Owner
`
`__________
`
`Case IPR2013-00362
`
`Patent 7,348,575
`
`__________
`
`PATENT OWNER’S RESPONSE TO THE PETITION
`
`
`
`
`
`
`
`Mail Stop "PATENT BOARD"
`Patent Trial and Appeal Board
`U.S. Patent and Trademark Office
`P.O. Box 1450
`Alexandria, VA 22313-1450
`
`

`

`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
` 
`
`TABLE OF CONTENTS
`
`Introduction ...................................................................................................... 1
`I.
`II. Overview of Catadioptric Projection Optical Systems.................................... 1
`A. Advances in Projection Optical Systems Occur Rapidly but in Small
`Increments .................................................................................................. 1
`B. The Race to Design a Projection Optical System for Immersion
`Lithography ................................................................................................ 5
`C. Zeiss Pursues Dioptric Solutions ................................................................ 5
`D. Nikon Pursues Catadioptric Solutions and Is First to Enable and Patent a
`Catadioptric Projection Optical System for Immersion Lithography ........ 9
`III. The 575 Patent ............................................................................................... 10
`A. Compact Projection Optical System ......................................................... 12
`B. Excellent Imaging Performance (Aberration Correction) ........................ 13
`C. Reflection Loss on Optical Surfaces ........................................................ 14
`D. Optical Beam Separation .......................................................................... 14
`IV. Level of Skill in the Art ................................................................................. 15
`V.
`Claim Construction ........................................................................................ 16
`A. Applicable Law......................................................................................... 16
`B. Boundary lens ........................................................................................... 16
`VI. Prior Art ......................................................................................................... 18
`A. Terasawa ................................................................................................... 18
`B. Immersion References .............................................................................. 19
`i. Suwa .................................................................................................... 19
`ii. Ulrich ................................................................................................... 21
`iii. Switkes ................................................................................................ 22
`iv. Fukami ................................................................................................. 24
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
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`
`
`VII. The Prior Art Does Not Enable the Claimed Invention ................................ 25
`A. An Unpatentability Challenge Fails if Based on Prior Art Combinations
`That Do Not Enable the Claimed Invention ............................................. 25
`B. Terasawa and the Immersion References Fail to Enable the Invention
`Claimed in the 575 Patent......................................................................... 26
`VIII. Mr. Juergens is Not an Expert in Projection Optical Systems ...................... 35
`IX.
`Independent Claim 1 is not Obvious ............................................................. 38
`X.
`Secondary Considerations ............................................................................. 43
`XI. The Dependent Claims Are Not Obvious ...................................................... 47
`XII. Conclusion ..................................................................................................... 47
`
`
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
` 
`
`TABLE OF AUTHORITIES
`
`
`
`
`Beckman Instruments, Inc. v. LKB Produkter AB,
`
`892 F.2d 1547 (Fed. Cir. 1989)) .................................................................... 28
`
`Broadcom Corp. v. Emulex Corp., 732
`
`F.3d 1325 (Fed. Cir. 2013) ............................................................................ 42
`
`Graham v. John Deere Co.,
`
`383 U.S. 1 (1966) ........................................................................................... 46
`
`In re Kumar,
`418 F.3d 1361 (Fed. Cir. 2005) .......................................................................... 28
`
`In re Translogic Tech., Inc.,
`
`504 F.3d 1249 (Fed. Cir. 2007) ..................................................................... 19
`
`
`In re Wands,
`
`858 F.2d 731 (Fed. Cir. 1988) ........................................................... 28, 34, 38
`
`Kinetic Concepts, Inc. v. Smith & Nephew, Inc.,
`
`688 F.3d 1342 (Fed. Cir. 2012) ..................................................................... 46
`
`McGinley v. Franklin Sports, Inc.,
`
`262 F.3d 1339 (Fed. Cir. 2001)) .................................................................... 46
`
`Power Integrations Inc. v. Fairchild Semiconductor Int’l Inc.,
`
`711 F.3d 1348 (Fed. Cir. 2013) ..................................................................... 46
`
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
` 
`
`I.
`
`Introduction
`
`
`
`On December 16, 2013, the Board ordered Inter Partes Review of U.S.
`
`Patent No. 7,348,575 (“the 575 Patent,” Ex. 1001), instituting review on the
`
`following grounds:
`
`1) Claims 1-3, 8-12, 16-20, 23-26, 29, and 31-33 are obvious under 35
`
`U.S.C. §103(a) over Terasawa in view of the Immersion References; and
`
`2) Claim 30 as obvious under §103(a) over Terasawa in view of the
`
`Immersion References, and further in view of Asai. (Decision, Paper 10.)
`
`For at least the reasons described below, the Board should confirm the patentability
`
`of claims 1-3, 8-12, 16-20, 23-26, and 29-33 of the 575 Patent.
`
`II. Overview of Catadioptric Projection Optical Systems
`
`A. Advances in Projection Optical Systems Occur Rapidly but in
`Small Increments
`
`
`
`At the heart of the semiconductor development process is the lithographic
`
`step in which a projection optical system is used to expose a pattern image of a
`
`mask (or reticle) onto a wafer coated with a photo resist layer. In order to keep
`
`pace with the demand for higher and higher integration of semiconductor elements,
`
`the resolution of projection optical systems must improve. Moore’s Law provides
`
`the observation that the number of transistors on integrated circuits doubles
`
`approximately every two years. (Ex. 2002 83.) This phenomenon of increasing
`
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`miniaturization, known long before the 2003 filing date of the 575 patent, is
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
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`charted in the 2003 International Technology Roadmap for Semiconductors. (Ex.
`
`2003, “Technology Roadmap”.) The Technology Roadmap tracked the advances
`
`made in past semiconductor device construction and provided opinions on the
`
`future directions of research for semiconductor development, i.e., post-2003. (Ex.
`
`2003 16.)1 The principles set forth in the Technology Roadmap and Moore’s Law
`
`demonstrate that companies involved in the manufacture of semiconductor devices
`
`constantly strive to improve upon their designs in order to match the rabid demand
`
`for smaller and smaller devices. In the field of projection optical systems, these
`
`principles apply equally to the demand for higher resolution.
`
`
`
`The increments by which resolution is improved in lithography are called
`
`“technology nodes.” They are often referred to by the average half-pitch of the
`
`resulting memory cell generated at that resolution, for example, “the 65 nm node.”
`
`(Ex. 2003 15, Fig. 53.)
`
`
`
`Various patents and published patent applications for catadioptric projection
`
`optical systems are provided as Exhibits 2007 through 2020 and 2027. One of the
`
`                                                            
`1 Unless indicated otherwise, citations are to original page or column number.
`
`Citations to line numbers are preceded by colon, i.e., page:line or column:line.
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`2
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`first catadioptric projection systems is described in Nikon’s U.S. Patent No.
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
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`4,812,028 (Ex. 2007), dated July 23, 1984:
`
`
`
`(Ex. 2007 Fig. 7.)
`
`Such catadioptric projection systems were predominantly multi-axis systems
`
`until the mid-1990’s when SVGL developed technology disclosed in U.S. Patent
`
`No. 5,815,310 (Ex. 2013) directed to a uni-axis catadioptric projection system:
`
`
`
`(Ex. 2013 Fig. 3.)
`
`
`
`Nikon and Zeiss followed up with inline catadioptric systems of their own,
`
`as seen by their patent filings in 1999 and 2000, respectively, shown in the
`
`following table:
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
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`Nikon, Ex. 2014
`Fig. 2
`
`Zeiss, Ex. 2015
`Fig. 3
`
`
`
`Although immersion lithography – the practice of using liquids with higher
`
`
`
`
`
`refractive indices than air to fill the space between the boundary lens of the
`
`projection system and the wafer – was viewed as a possible way to increase
`
`numerical aperture and consequently resolution (See, Ex. 2003 Fig. 53), it was
`
`many years after the first patenting and commercialization of catadioptric
`
`projection systems in the 1980s that companies were able to employ immersion
`
`lithography with projection optical systems, as shown by the Nikon and Zeiss
`
`systems below:
`
`Nikon, Ex. 1001
`Fig. 14
`
`
`
`Zeiss, Ex. 2020
`Fig. 36
`
`
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`4
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
` 
`
`B. The Race to Design a Projection Optical System for Immersion
`Lithography
`
`
`
`By 2003, industry leaders such as Nikon and Zeiss had squeezed most of the
`
`potential they could out of catadioptric uni-axis systems, but the ever-present
`
`customer demand for higher resolution projection optical systems still existed.
`
`(See, e.g., Ex. 2002; Ex. 2003.) By that time, both companies had turned their
`
`sights toward increasing resolution of projection optical systems by using
`
`immersion technology. (See, e.g., Ex. 1011; Ex. 2006.)
`
`
`
`Interestingly, Nikon and Zeiss chose separate paths to the finish line in the
`
`race to enable immersion lithography for projection optics. On one hand, Nikon
`
`pursued the use of immersion techniques with the catadioptric, uni-axis systems
`
`that it had been developing, such as that shown in U.S. Patent No. 7,030,965. (Ex.
`
`2018.) On the other hand, Zeiss, consistent with its earlier efforts, pursued dioptric
`
`projection optical systems (Ex. 1011 159:3-4.) This is also evidenced in retrospect
`
`by a 2005 Zeiss article authored by Zeiss engineers Heiko Feldmann and Wilhelm
`
`Ulrich, among others. (Ex. 2005 “the Zeiss article.”)
`
`C. Zeiss Pursues Dioptric Solutions
`
`
`
`As noted in the Zeiss article, “dioptric lenses started to dominate the
`
`development [in the design history of projection lenses for lithography].” (Ex.
`
`2005 1:13.) But the article acknowledges that dioptric projection systems were not
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
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`feasible for immersion lithography: “[D]uring the first studies on extreme high NA
`
`immersion designs, it became clear that this dioptric concept leads to extremely
`
`large designs beyond approximately NA = 1.1, using an extreme amount of optical
`
`material. So the most important motivation to look for catadioptric systems now is
`
`to find another way to satisfy the Petzval condition and in this way to obtain a
`
`compact system at reasonable costs.” (Ex. 2005 1:29-33.)
`
`
`
`The Zeiss article recognizes that simply introducing immersion techniques in
`
`a catadioptric projection system is not a matter of routine design. “In contrast to
`
`other design means like e.g. aspheres or diffractive elements, mirrors cannot be
`
`introduced smoothly into a design concept: they immediately pose the problem of
`
`separating the incident and the reflective beam.” (Ex. 2005 2:1-2, references
`
`omitted.) Additionally, the authors observed that “When the NA increased further
`
`for immersion lithography, the beam separation became and more and more
`
`difficult issue.” (Ex. 2005 3:6.) In developing a solution to this problem, Zeiss
`
`encountered several surprises:
`
`The recipe to move the folding mirrors as close as possible to a field
`plane seemed to be exhausted. Now the development of an interesting
`twist: A new complete relay system was added to the designs just to
`follow this recipe even more rigorously. Surprisingly, the system
`gained from this step greatly out-balanced the additional effort.
`Today, these folded catadioptric lithography designs reach numerical
`
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
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`apertures higher than NA 1.2 within the same volume that previous
`concepts used around in 0.9.
`
`A second surprise was the attempt to add again one subsystem, this
`time a new catadioptric system on the yet unoccupied side of the
`central folding region. With the second mirror, a better control over
`color, field curvature and higher aberrations rendered the total system
`approximately as advantageous in terms of dimensions and weight as
`the one mirror version.
`
`(Ex. 2005 3:7-15, emphasis added.)
`
`
`
`Figure 3 of the Zeiss article shows that these “surprise” catadioptric
`
`solutions all involved multi-axis systems. Zeiss engineers found the multi-axis
`
`solutions unsatisfactory for a handful of reasons, including the additional effort
`
`required to manufacture an optical system with more than one axis, high incidence
`
`angles resulting from tilted folding mirrors, reflections leading to a degradation of
`
`the polarization behavior which breaks the rotational symmetry of the system, and
`
`the fact that most folded systems have an odd number of mirrors which flips the
`
`image and renders them incompatible with reticles for traditional dioptric lenses.
`
`(Ex. 2005 4:1-11.)
`
`
`
`Accordingly, Zeiss set about to develop an in-line (uni-axis) system. They
`
`recognized the importance of keeping a compact system even though the earliest
`
`catadioptric in-line systems had a relatively small usable section of the field height,
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`which would force designers “to scale up the design by a large factor to obtain an
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
` 
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`image field of sufficient size.” (Ex. 2005 4:29-30.) Thus, a major issue
`
`confronting the Zeiss authors was how to construct a catadioptric in-line system
`
`with better beam separation to allow a larger field size without increasing the
`
`system length. (Ex. 2005 4:36-37.) The Zeiss authors observed that, by adding a
`
`new catadioptric relay system, “four mirrors allow[ed] several combinations of
`
`color correcting means.” (Ex. 2005 5:22-23, attributing this “discovery” to Ex.
`
`1014, Nikon’s EP1336887A1.) Again, the Zeiss authors learned a “surprising”
`
`lesson from catadioptric projection systems. (Ex. 2005 5:28.) They found that
`
`“the introduction of additional intermediate images, which enhances the system
`
`complexity at the first glance, does not increase volume or weight of the lens. In
`
`some cases, the results even surpass the ‘simpler’ designs.” (Ex. 2005 5:28-30.)
`
`
`
`This surprising lesson led to Zeiss’ additional research and experimentation
`
`with intermediate images. In one approach, shown in Figure 7 of the Zeiss article,
`
`the size of the intermediate image is increased to ease vignetting control.
`
`Additionally, the Zeiss authors, recognizing that the two-mirror design in Figure 7
`
`requires large refractive elements to capture the divergent chief rays at the
`
`intermediate image (Ex. 2005 6:4-11), researched four-mirror designs as shown in
`
`Figure 8, for example, because it is easier to produce large diameter lithographic
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`8
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`

`

`quality mirrors than it is large diameter lithographic quality lenses (Ex. 2005 6:10-
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
` 
`
`18).
`
`D. Nikon Pursues Catadioptric Solutions and Is First to Enable and
`Patent a Catadioptric Projection Optical System for Immersion
`Lithography
`
`
`
`As noted above, Nikon chose the catadioptric route in the race to develop
`
`projection optical systems for immersion lithography. In a June 25, 2003 article
`
`written by Nikon engineers, including the inventor of the 575 patent, Nikon
`
`determined that “it is almost impossible for traditional dioptric optics to realize
`
`these specifications [i.e., over 1.0 NA at 193nm lithography by liquid immersion].”
`
`(Ex. 2006 781:5-6). The Nikon authors went on to explain why they chose the
`
`catadioptric route over the dioptric route for immersion lithography:
`
`[A]s long as we persist in the dioptric, its lens diameter will go over a
`practical limit immediately. I would say, “The next breakthrough will
`be brought by Catadioptric”. It will make possible to realize over
`1.2NA optics.
`
`(Ex. 2006 784:4-6.)
`
`
`
`In hindsight, the catadioptric route that Nikon took was the better choice for
`
`high NA immersion lithography. This is evidenced by Zeiss’s own article (Ex.
`
`2005) and the fact that Nikon became the first to both enable and file a patent
`
`application for a catadioptric optical projection system for immersion lithography.
`
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`9
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`

`In fact, the catadioptric designs that Zeiss’ engineers found “surprising” (Ex. 2005
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
` 
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`5:28-30), largely resemble the projection systems shown in the 575 patent.
`
`Nikon 575 Patent (Ex. 1001)
`
`Zeiss’s 2005 Article (Ex. 2005)
`
`
`
`
`
`Fig. 7
`
`Fig. 8
`
`
`
`
`
`Fig. 5
`
`Fig. 9
`
`
`
`III. The 575 Patent
`
` The 575 Patent provides for the first time a complete specification for an
`
`immersed lithographic catadioptric system that is compact, provides high
`
`resolution, off-axis imaging, and is inline. In other words, the 575 Patent provided
`
`a timely, important, and new technology to meet the industry’s needs. (Ex. 2024 ¶
`
`53.)
`
`
`
`While agreeing generally with Zeiss’ description of the 575 Patent in its
`
`Petition, Nikon believes that description fails to recognize some key disclosures in
`
`the 575 Patent that allow a person of ordinary skill in the art (POSITA) to make
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`10
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`and use the claimed catadioptric projection optical system. Thus, Nikon’s
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
` 
`
`description of the 575 Patent below will focus mainly on these disclosures.
`
` In a background section, the 575 Patent confirms that immersion was a known
`
`technology for increasing numerical aperture. (Ex. 1001 1:55-58.) However, it
`
`was not until the invention of the 575 Patent that this known technology was
`
`successfully applied to inline catadioptric projection optical systems. To the
`
`contrary, prior to the invention of the 575 Patent, immersion technology had only
`
`been used with dioptric systems, and it was known that that these immersed
`
`dioptric systems suffered from several disadvantages. For example, the 575 Patent
`
`confirms that with immersed dioptric systems it was difficult to: 1) well correct
`
`for chromatic aberration; 2) satisfy Petzval’s condition to well correct for curvature
`
`of field; 3) reduce the scale of the optical system; and 4) secure a large effective
`
`image-side numerical aperture while well suppressing the reflection loss on optical
`
`surfaces. (Ex. 2024 ¶ 54.) Specifically, the 575 Patent explains that:
`
`However, application of this [immersion] technology to the ordinary
`dioptric projection optical systems caused such disadvantages that it
`was difficult to well correct for chromatic aberration and to satisfy the
`Petzval’s condition to well correct for curvature of field, and that an
`increase in the scale of the optical system was inevitable. In addition,
`there was another disadvantage that it was difficult to secure a large
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
` 
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`effective image-side numerical aperture while well suppressing the
`reflection loss on optical surfaces.
`(Ex. 1001 1:59-67.)
`
`The inventor of the 575 Patent not only recognized that an immersed
`
`catadioptric projection optical system would solve the disadvantages inherent with
`
`an immersed dioptric system, but also provided a relatively compact projection
`
`optical system having excellent imaging performance that is well corrected for
`
`various aberrations, such as chromatic aberration and curvature of field. The
`
`inventor of the 575 patent also disclosed a projection optical system capable of
`
`securing a large effective image-side numerical aperture while well suppressing the
`
`reflection loss on optical surfaces. (Ex. 1001 2:3-9.) An indispensable feature in
`
`the 575 Patent is the manufacturability of the embodiments to suit exposure tools.
`
`(Ex. 2024 ¶ 55.)
`
`A. Compact Projection Optical System
`
`
`
` The 575 Patent includes mirrors that fold the beam of light, thereby
`
`reducing system length, and negative optically powered lenses that allow for a
`
`decrease in projection systems length. The result is a compact system having a
`
`shorter length and diameter that permits practical manufacturing. The selection of
`
`lens element diameter to central thickness are compatible with lenses that can be
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`made, while at the same time minimizing material by minimizing lens diameter
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
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`and number of lenses with large diameter. (Ex. 2024 ¶ 56.)
`
`
`
`A POSITA would understand that a practical projection lens is a part of an
`
`exposure tool that must be transported and installed in a room. Therefore the length
`
`of the projection lens is a critical packaging specification. A POSITA would have
`
`understood that the manufacturing and use of lens elements with diameters larger
`
`than 350 mm presents substantial problems. The 575 patent provides embodiments
`
`with lengths of less than 1500 mm and diameters of about 300 mm. The scale of
`
`the projection lenses is possible due to the mirrors used and the negative optically
`
`powered lenses. (Ex. 2024 ¶ 57.)
`
`
`
`Examples 1 and 2 that are shown in Figures 5 and 7, respectively, of the 575
`
`Patent provide two mirrors that comparatively have a small size and spacing
`
`between them and can be handled as if they were a lens module. Thus, the
`
`projection lens could use the then-existing technology of packaging dioptric lenses,
`
`and therefore be easily manufactured. (Ex. 2024 ¶ 58.)
`
`B. Excellent Imaging Performance (Aberration Correction)
`
`
`
`The projection systems described in the 575 Patent employ mirrors and
`
`lenses positioned to correct for the various optical aberrations and allow excellent
`
`imaging, as confirmed by the aberration curves shown, for example, in Figures 6
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`and 8 of the 575 Patent. Ray deviations from perfection are substantially less than
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
` 
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`one micrometer for the three light wavelengths used. The specific arrangement of
`
`the optical elements in the 575 Patent permits a high degree for correction of
`
`optical aberrations. The inclusion of the boundary lens in combination with an
`
`immersion liquid permits a higher resolution than in previous dry projection lenses.
`
`(Ex. 2024 ¶ 59.)
`
`C. Reflection Loss on Optical Surfaces
`
`
`
`The inclusion of a boundary lens and immersion liquid prevents severe loss
`
`of light for rays that otherwise would be reflected. (Ex. 1001 5:22-31.) The
`
`selection of lens curvatures also contributes to reduce light reflection loss. The
`
`path of the rays throughout all the lenses minimizes ray angle of incidence in order
`
`to not only reduce reflection loss, but also large aberrations. (Ex. 2024 ¶ 60.)
`
`D. Optical Beam Separation
`
`
`
`In providing high resolution, the embodiments of the 575 Patent avoid beam
`
`overlap within the mirrors, and therefore the systems provide an unobscured (un-
`
`shielded) exit pupil. This is achieved by the positioning of intermediate images
`
`and pupils. The cross-section of the most off-axis mirror is kept small which is an
`
`important manufacturing item. The optical design also maintains a small lens
`
`element diameter, and thus a compact projection optical system. (Ex. 2024 ¶ 61.)
`
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`IV. Level of Skill in the Art
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
` 
`
`
`
`Nikon disagrees with level of ordinary skill in the art that has been proposed
`
`by Zeiss’ expert, Mr. Juergens. Photolithography is an extremely specialized area
`
`within the field of optical design. While Nikon agrees that education and
`
`experience in the generalized field of optical design are required, a POSITA at the
`
`time of the invention of the 575 Patent would have additionally been involved for
`
`at least two years in the lithography optics industry and had experience in the
`
`specification of projection optical systems. (Ex. 2024 ¶ 62.)
`
`
`
`To the contrary, the level of ordinary skill proposed by Mr. Juergens in his
`
`expert declaration does not require that a POSITA have any experience with
`
`projection optical system design. Instead, Mr. Juergens posits that a POSITA
`
`“would typically have had two or more years of post-graduate level education or
`
`equivalent experience, with emphasis and experience in the field of optical
`
`design.” (Ex. 1016 ¶ 22.) Additionally, Mr. Juergens only requires that a POSITA
`
`have experience with optical design software to determine the optical design
`
`properties of optical systems, but doesn’t specifically require such experience with
`
`projection optical systems. (Ex. 1016 ¶¶ 22, 23.)
`
`
`
`Because of the highly specialized nature of projection optical systems within
`
`the field of optical design, a POSITA would need more than a general background
`
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
` 
`in optical design and optical design software. Thus, in addition to level of ordinary
`
`skill in the art set forth by to Mr. Juergens, Nikon has shown that a POSITA would
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`additionally have been involved for at least two years in the lithography optics
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`industry and have had experience in the specification of projection optical systems.
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`V. Claim Construction
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`A. Applicable Law
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`In an inter partes review, claim terms in an unexpired patent are interpreted
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`according to their broadest reasonable construction in light of the specification of
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`the patent in which they appear. 37 C.F.R. § 42.100(b). Also, claim terms are
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`given their ordinary and customary meaning, as would be understood by one of
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`ordinary skill in the art in the context of the entire disclosure. In re Translogic
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`Tech., Inc., 504 F.3d 1249, 1257 (Fed. Cir. 2007).
`
`B. Boundary lens
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`
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`In the context of the 575 Patent, a boundary lens is a lens of the projection
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`optical system that has a convex object-side surface and a flat image-side surface
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`to increase effective NA in the presence of the immersion liquid by reducing
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`reflection loss. (Ex. 1001 5:22-31, Tables 1-11; Ex. 2024 ¶ 66.) As opposed to
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`just any lens that happens to be placed in contact with an immersion liquid, a
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`POSITA would understand from the disclosure of the 575 Patent that the term
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`boundary lens has a more particular meaning. As such, Nikon disagrees with
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
` 
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`Zeiss’ construction of the term boundary lens because Zeiss’ construction is overly
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`broad. Likewise, Nikon respectfully disagrees with the Board’s adoption of Zeiss’
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`construction of this term. (Ex. 2024 ¶ 75.)
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`
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`The 575 Patent is directed to a high-resolution catadioptric projection optical
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`system. (Ex. 1001 1:18-23.) As taught by the 575 Patent, the projection optical
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`system includes a boundary lens that is in contact with an immersion fluid. The
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`object-side of the boundary lens has positive refracting power to reduce reflection
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`loss. This in turn allows a large image-side numerical aperture to be obtained.
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`(Ex. 1001 5:22-31; Ex. 2024 ¶ 67.)
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`
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`
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`The 575 Patent teaches a boundary lens Lb having an object-side surface Sb
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`with a positive refracting power and an image-side surface that is planar, and thus,
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`has no refracting power. (Ex. 2024 ¶ 68.) As shown above in reproduced Figure 3
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`of the 575 Patent, the planar wafer-side surface of the boundary lens Lb is in
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
` 
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`contact with an immersion medium Lm. (Ex. 2024 ¶ 68.)
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`
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`In light of the specification, a POSITA would have understood that a
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`boundary lens needed to be designed to not only isolate an atmosphere of the
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`projection optical system, but also stand a higher fluence from the light source and
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`enable higher resolution by reducing reflection losses. (Ex. 2024 ¶¶ 70-75.) Thus,
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`when construed properly, it is apparent that simply placing a dry projection optical
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`system into an immersion medium does not convert the last lens element into a
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`boundary lens. (Ex. 2024 ¶ 75.)
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`VI. Prior Art
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`A. Terasawa
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`
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`Terasawa is directed to a “dry” catadioptric projection system. In light of
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`the fact that the use of immersion technology with a catadioptric projection system
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`had yet to be invented at the time of Terasawa’s filing, it is no surprise that
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`Terasawa fails to include any disclosure about immersion. Further, because
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`Terasawa’s disclosure is only directed to a dry system, Terasawa fails to teach
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`other claim limitations recited in the 575 Patent. For example, Terasawa does not
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`disclose a boundary lens, as recited in independent claim 1. (Ex. 2024 ¶ 76.)
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
` 
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`Again, Terasawa is a dry system, and thus was not concerned with the
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`
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`optical, thermal, and mechanical difficulties associated with the projection optical
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`system interacting with an immersion fluid. Thus, as explained above, Terasawa
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`fails to disclose a boundary lens, as required by independent claim 1 of the 575
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`Patent. For example, while Zeiss concedes (as it must) that Terasawa teaches a dry
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`projection optical system, Zeiss asserts that if Terasawa’s projection optical system
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`were immersed, then the last lens element would become a boundary lens. (Pet.
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`34:9-12; Ex. 1016 ¶ 198). Nikon disagrees because, not only is Terasawa silent
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`with respect to whether its last lens element is designed to stand a higher fluence
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`from the light source and isolate an atmosphere of the projection optical system,
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`but the last lens in Terasawa’s system is not designed to enable higher resolution
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`by reducing reflection losses. (Ex. 2024 ¶¶ 76-77.)
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`B. Immersion References
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`i. Suwa
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`
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`Suwa fails to teach using a catadioptric projection system with immersion,
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`let alone teaching how a POSITA would modify a catadioptric projection system to
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`operate with immersion. In its Petition, Zeiss relies on the disclosure in Suwa for
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`“teach[ing] the immersion limitation that is missing from … Terasawa.” (Pet.
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`44:4-5.) However, Suwa’s disclosure adds nothing more than what is already
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`taught by Nikon in the Background of the 575 patent. Immersion was known, and
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`Patent Owner’s Response to the Petition
`IPR2013-00362
`Patent 7,348,575
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`immersion can be used to increase numerical aperture NA, and thus, increase
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`resolution. (Ex. 1009 3:18-33; Ex. 2024 ¶ 78.)
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`
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`The vast majority of the Suwa disclosure is directed to a projection aligner
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`that performs high precision positioning, such as focus and tilt control, of a
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`workpiece beneath a projection optical system. (Ex. 1009 5:17-23.) As described
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`below, Suwa describes immersion in two places, but in each instance, Suwa i