UNITED STATES PATENT AND TRADEMARK OFFICE
`
`_________________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`_________________
`
`HAMAMATSU CORPORATION
`Petitioner,
`
`v.
`
`PRESIDENT AND FELLOWS OF HARVARD COLLEGE
`Patent Owner.
`
`_________________
`
`Case No. To Be Assigned
`Patent No. 8,080,467 B2
`_________________
`
`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 8,080,467
`UNDER 35 U.S.C. §§ 311-319 AND 37 CFR §§ 42.100 et seq.
`
`

`

`Docket No.: 685399-18IPR
`
`TABLE OF CONTENTS
`
`I.
`
`page
`MANDATORY NOTICES (37 C.F.R. § 42.8(a)(1))......................................1
`A. Real Party-In-Interest (37 C.F.R. § 42.8(b)(1)) ...............................................1
`B. Related Matters (37 C.F.R. § 42.8(b)(2)).........................................................1
`C. Lead and Backup Counsel (37 C.F.R. § 42.8(b)(3))........................................1
`D. Service Information (37 C.F.R. § 42.8(b)(4)) ..................................................2
`II.
`GROUNDS FOR STANDING (37 C.F.R. § 42.104(a)).................................2
`III.
`STATEMENT OF PRECISE RELIEF REQUESTED (37 C.F.R.
`§ 42.104(b)) .....................................................................................................2
`THE (cid:145)467 PATENT.........................................................................................2
`IV.
`A. Overview of the (cid:145)467 Patent.............................................................................2
`B. The Priority Date of the (cid:145)467 Patent Claims is September 24, 2004...............6
`C. Prosecution History of the (cid:145)467 Patent ............................................................9
`D. One of Ordinary Skill in the Art.....................................................................11
`E. Claim Construction.........................................................................................11
`V.
`THERE IS A REASONABLE LIKELIHOOD THAT PETITIONER
`WILL PREVAIL WITH RESPECT TO AT LEAST ONE
`CHALLENGED CLAIM OF THE (cid:145)467 PATENT.......................................12
`A. Prior Art..........................................................................................................12
`1. Wu Thesis....................................................................................................12
`a. Wu Thesis is at Least a June 2001 Printed Publication Under
`35 U.S.C. § 102(b) ..................................................................................12
`b. The Teachings of Wu Thesis ...................................................................14
`2. Gibbons .......................................................................................................16
`3. Wu Article...................................................................................................18
`4. Carey ...........................................................................................................20
`
`i
`
`

`

`Docket No.: 685399-18IPR
`
`B. Ground I: Claims 1-2 and 6-8 are Obvious Under 35 U.S.C.
`§ 103(a) Over Wu Thesis in View of Gibbons..............................................21
`1. Claim 1 ........................................................................................................21
`a. Preamble...................................................................................................24
`b. Doping Step..............................................................................................24
`c. Annealing Step.........................................................................................25
`2. Claim 2 ........................................................................................................27
`3. Claim 6 ........................................................................................................27
`4. Claim 7 ........................................................................................................28
`5. Claim 8 ........................................................................................................29
`C. Ground II: Claims 1-2 and 6-8 are Obvious Under 35 U.S.C.
`§ 103(a) Over Wu Article in View of Gibbons.............................................30
`1. Claim 1 ........................................................................................................30
`a. Preamble...................................................................................................33
`b. Doping Step..............................................................................................33
`c. Annealing Step.........................................................................................34
`2. Claim 2 ........................................................................................................35
`3. Claim 6 ........................................................................................................36
`4. Claim 7 ........................................................................................................36
`5. Claim 8 ........................................................................................................37
`D. Ground III: Claim 3 is Obvious Under 35 U.S.C. § 103(a) Over
`Wu Thesis in View of Gibbons and Carey....................................................38
`E. Ground IV: Claim 3 is Obvious Under 35 U.S.C. § 103(a) Over
`Wu Article in View of Gibbons and Carey...................................................39
`VI. CONCLUSION .............................................................................................41
`
`ii
`
`

`

`Docket No.: 685399-18IPR
`
`Description
`
`EXHIBIT LIST
`Exhibit
`No.
`1001
`1002
`1003
`1004
`1005
`1006
`
`U.S. Pat. No. 8,080,467 B2
`File History for U.S. Pat. No. 8,080,467 B2
`U.S. Prov. Pat. App. No. 60/293,590
`U.S. Pat. App. No. 10/155,429
`U.S. Pat. App. No. 10/950,230
`(cid:147)Femtosecond laser-gas-solid interactions,(cid:148) Thesis presented by Claudia
`Wu to Dept. of Physics of Harvard University, August 2000 ((cid:147)Wu
`Thesis(cid:148))
`(cid:147)Ion Implantation in Semiconductors(cid:151)Part II: Damage Production and
`Annealing,(cid:148) James F. Gibbons, Proceedings of the IEEE vol. 60, no. 9,
`pp. 1062 (cid:150) 1096 (1972) ((cid:147)Gibbons(cid:148))
`(cid:147)Near-unity below-band-gap absorption by microstructured silicon,(cid:148) C.
`Wu, et al., App. Phys. Letters, V.78, No. 13 (2001) ((cid:147)Wu Article(cid:148))
`(cid:147)In-situ Doping of Silicon Using the Gas Immersion Laser Doping
`(GILD) Process,(cid:148) P.G. Carey, et al., Appl. Surf. Sci. 43, 325-332 (1989)
`Excerpts from Dissertations Abstracts Int(cid:146)l Section B, Vol. 61, No. 12
`(June 2001)
`Harvard Library On-Line Record for Wu Thesis
`Declaration of Shukri J. Souri, Ph.D.
`
`1007
`
`1008
`
`1009
`
`1010
`
`1011
`1012
`
`iii
`
`

`

`Docket No.: 685399-18IPR
`
`I.
`
`MANDATORY NOTICES (37 C.F.R. § 42.8(a)(1))
`
`A.
`
`Real Party-In-Interest (37 C.F.R. § 42.8(b)(1))
`
`The petitioner is Hamamatsu Corporation ((cid:147)Petitioner(cid:148)). The real parties-in-
`
`interest in addition to Petitioner are: Hamamatsu Photonics K.K. and Photonics
`
`Management Corporation.
`
`B.
`
`Related Matters (37 C.F.R. § 42.8(b)(2))
`
`USPTO records indicate that U.S. Pat. App. No. 15/003,210 is currently
`
`pending and claims priority to U.S. Pat. No. 8,080,467 ((cid:147)the (cid:145)467 Patent(cid:148)), which
`
`is the subject of the present Petition. The (cid:145)467 Patent has been asserted against
`
`Petitioner and HPK in a complaint filed October 1, 2015 in the U.S. District Court
`
`for the District of Massachusetts (SiOnyx LLC, et al. v. Hamamatsu Photonics
`
`K.K., et al., Civil Action No. 1:2015-cv-13488), which was superseded by an
`
`amended complaint filed December 18, 2015, which added one of Petitioner(cid:146)s
`
`customers as a defendant. Petitioner was not served with the original complaint,
`
`but accepted service of the amended complaint on February 26, 2016. HPK was
`
`finally served on September 30, 2016.
`
`C.
`
`Lead and Backup Counsel (37 C.F.R. § 42.8(b)(3))
`
`Lead counsel is John D. Simmons (Reg. No. 52,225). Backup counsel are
`
`Stephen E. Murray (Reg. No. 63,206) and Keith A. Jones (Reg. No. 67,781).
`
`1
`
`

`

`Docket No.: 685399-18IPR
`
`D.
`
`Service Information (37 C.F.R. § 42.8(b)(4))
`
`Service information for Petitioner is as follows: John D. Simmons, Panitch
`
`Schwarze Belisario & Nadel LLP, 2005 Market St., Suite 2200, Philadelphia, PA
`
`19103-7013, Tel: 215-965-1330, Fax: 215-965-1331. Petitioner consents to email
`
`service at uspto@panitchlaw.com with copy to jsimmons@panitchlaw.com,
`
`smurray@panitchlaw.com, and kjones@panitchlaw.com.
`
`II. GROUNDS FOR STANDING (37 C.F.R. § 42.104(a))
`Petitioner hereby certifies that the (cid:145)467 patent is available for Inter Partes
`
`Review and that Petitioner is not barred or estopped from requesting an Inter
`
`Partes Review challenging the patent claims on the grounds identified in this
`
`Petition.
`
`III.
`
`STATEMENT OF PRECISE RELIEF REQUESTED (37 C.F.R.
`§ 42.104(b))
`Petitioner respectfully requests Inter Partes Review, under 35 U.S.C.
`
`§§ 311-319 and 37 C.F.R. § 42.100, et seq. of claims 1-3 and 6-8 of the (cid:145)467
`
`Patent, and cancellation of each of these claims as being unpatentable for the
`
`reasons set forth in detail in section V., below.
`
`IV. THE (cid:145)467 PATENT
`
`A.
`
`Overview of the (cid:145)467 Patent
`
`The (cid:145)467 Patent is directed to a method of fabricating a semiconductor
`
`wafer, particularly a silicon wafer, for use in a photodetector. (Ex. 1001 at
`
`2
`
`

`

`Docket No.: 685399-18IPR
`
`Abstract; cl. 1; Ex. 1012 at ¶ 26). A pulsed laser, in conjunction with a selected
`
`gas ambient, is used to microstructure a surface of the wafer with the aim of
`
`enhancing the material(cid:146)s ability to detect light, especially at longer wavelengths
`
`(e.g., in the infrared range). (Ex. 1001 at 1:27-52; 3:62-64; Ex. 1012 at ¶¶ 26-27).
`
`The claimed method essentially combines two well-known semiconductor
`
`manufacturing processes: doping and annealing. (Ex. 1012 at ¶ 10). The attached
`
`Declaration of Shukri J. Souri, Ph.D. (Ex. 1012) briefly provides a background
`
`discussion of conventional techniques for manufacturing semiconductor devices,
`
`including photodetectors, at paragraphs 10-22 thereof. This description explains
`
`various well-known doping processes, such as gas immersion laser doping, which
`
`uses a pulsed laser to introduce charge carriers into the surface of a semiconductor
`
`material and create surface defects. (Id.). The description also explains the
`
`various purposes and effects of annealing that have been used for decades in the
`
`industry. (Id.). Finally, the description provides the basic architecture of a silicon
`
`photodetector, and the various factors which determine the photodetector(cid:146)s ability
`
`to absorb and convert light. (Id.).
`
`Briefly, doping involves the introduction of impurity or (cid:147)dopant(cid:148) atoms into
`
`a material such as silicon, in order to change its electronic properties. (Id. at ¶ 11).
`
`Common methods of doping include, for example, ion implantation, which
`
`involves bombarding the silicon surface with ionized dopant atoms that become
`
`3
`
`

`

`Docket No.: 685399-18IPR
`
`embedded below the surface, and the use of a pulsed laser, which rapidly diffuses
`
`atoms from an ambient solid or gas into the silicon surface. (Id. at ¶ 12).
`
`Annealing is a process involving the exposure of the silicon substrate to elevated
`
`temperatures in a controlled manner for a predetermined period of time. (Id. at
`
`¶ 11). Annealing typically occurs after a doping process, because the annealing is
`
`used to repair damage caused by the doping process, and to (cid:147)activate(cid:148) the dopant
`
`material in the silicon. (Id. at ¶¶ 14-15).
`
`Referring now to the alleged invention of the (cid:145)467 Patent, in the first step,
`
`the semiconductor surface is irradiated with (cid:147)a plurality of temporally short laser
`
`pulses(cid:148) while the surface is exposed to an electron donating substance (cid:147)so as to
`
`generate a plurality of surface inclusions containing at least a constituent of said
`
`substance(cid:148) in the substrate(cid:146)s surface layer. (Ex. 1001 at cl. 1; Fig. 1; Ex. 1012 at
`
`¶ 27). The dopant impurities add energy levels that enable increased absorption of
`
`lower energy (higher wavelength) photons by the silicon. (Ex. 1012 at ¶ 27). The
`
`(cid:145)467 Patent provides several ranges of parameters for the laser utilized in the
`
`process. For example, the laser has a central wavelength between 200-1200 nm, a
`
`pulse width between tens of femtoseconds and hundreds of nanoseconds, a
`
`repetition rate of 1 kHz-50 MHz, and a fluence between 1-12 kJ/m2. (Ex. 1001 at
`
`5:66-6:12). However, the (cid:145)467 Patent describes at least one exemplary laser
`
`arrangement, which is a regeneratively amplified, Ti:Sapphire laser system
`
`4
`
`

`

`Docket No.: 685399-18IPR
`
`providing 100 fs laser pulses with a central wavelength of 800 nm and a repetition
`
`rate of 1 kHz. (Id. at 6:64-67).
`
`The (cid:145)467 Patent describes the electron donating substance as primarily a gas
`
`or liquid, and more particularly as a sulfur-containing gas, such as SF6 or H2S. For
`
`the bulk of the specification, the (cid:145)467 Patent utilizes SF6 as the ambient for the
`
`creation of n-type electron donating impurities in the silicon. (Id. at 6:13-30; Ex.
`
`1012 at ¶ 28). This particular ambient gas results in the formation of a (cid:147)sulfur-rich
`
`layer(cid:148) in the silicon, having a sulfur concentration of 0.1-5 atom percent and
`
`exhibiting an undulating morphology with micron-sized surface height variations.
`
`(Ex. 1001 at 7:35-54; Fig. 3). The (cid:145)467 Patent does suggest other ambient gases,
`
`including Cl2, N2, and air. However, the (cid:145)467 Patent does not explain the purpose
`
`of inert gases, such as N2, which do not easily react chemically with other
`
`substances. (Id. at 6:18-21; 9:29-55; Ex. 1012 at ¶ 28). One of ordinary skill in the
`
`art would tend to use other nitrogen-containing gasses, such as NH3, for the
`
`purpose of doping. (Ex. 1012 at ¶ 28).
`
`Once the silicon substrate surface has been doped, the (cid:145)467 Patent calls for a
`
`step of annealing the substrate (cid:147)at an elevated temperature and for a duration
`
`selected to enhance a density of charge carriers in said surface layer.(cid:148) (Ex. 1001 at
`
`cl. 1; Fig. 1; Ex. 1012 at ¶ 29). Specifically, the (cid:145)467 Patent cautions that both the
`
`annealing temperature and duration must be carefully selected to optimize the
`
`5
`
`

`

`Docket No.: 685399-18IPR
`
`responsivity over a wide range of wavelengths, including infrared. (Ex. 1001 at
`
`11:13-27; 16:9-19; 17:9-55; Ex. 1012 at ¶ 29). In one embodiment, the annealing
`
`temperature and duration are preferably selected to increase the concentration of
`
`carrier electrons in the surface layer in the range of 10-200% while ensuring the
`
`finished wafer exhibits a responsivity greater than 20 A/W. (Ex. 1001 at 17:33-51;
`
`Ex. 1012 at ¶ 30). The (cid:145)467 Patent particularly recites annealing temperatures of
`
`between 500-1100 K (preferably between 500-900 K) for a time period between (cid:147)a
`
`few minutes(cid:148) and (cid:147)a few hours.(cid:148) (Ex. 1001 at 10:54-65).
`
`In sum, the alleged novelty of the (cid:145)467 Patent claims is directed to the
`
`combination of doping, for purposes of enhancing the optical absorption of silicon
`
`across a broad wavelength spectrum, and annealing, for the purpose of enhancing
`
`charge carrier density to alter the electrical properties of the detector. (Ex. 1012 at
`
`¶ 31). As explained below, this combination of steps would have been
`
`unsurprising and routine to one of ordinary skill in the art at the time of the
`
`invention.
`
`B.
`
`The Priority Date of the (cid:145)467 Patent Claims is September 24, 2004
`
`A claim is entitled to the benefit of an earlier application(cid:146)s filing date only if
`
`the claimed invention is fully supported by the earlier application. 35 U.S.C.
`
`§ 120. The earlier application must contain a description that one skilled in the art
`
`would understand as demonstrating that the inventor was (cid:147)in possession(cid:148) of the
`
`6
`
`

`

`Docket No.: 685399-18IPR
`
`entire claimed invention as of the priority date sought. See e.g., Arkema Inc. v.
`
`Honeywell Int(cid:146)l Inc., PGR2016-00012, Paper No. 13 at 16 (quoting Lockwood v.
`
`Am. Airlines, Inc., 107 F.3d 1565, 1571(cid:150)72 (Fed. Cir. 1997)). A description that
`
`merely renders the claimed invention obvious is insufficient. Id.
`
`The (cid:145)467 Patent claims priority through a chain of applications back to U.S.
`
`Provisional Patent Application No. 60/293,590 (Ex. 1003 (cid:150) (cid:147)the provisional
`
`application(cid:148)) filed on May 25, 2001. However, one of the applications in the
`
`priority chain, U.S. Patent Application No. 10/950,230 (Ex. 1005 (cid:150) (cid:147)the CIP(cid:148)), was
`
`filed on September 24, 2004 as a continuation-in-part of its predecessor, and was
`
`the first application to actually support the entire subject matter claimed in the (cid:145)467
`
`Patent.
`
`Specifically, independent claim 1 (from which all other claims in the (cid:145)467
`
`Patent depend) recites a step of (cid:147)annealing said substrate at an elevated
`
`temperature and for a duration selected to enhance a density of charge carriers in
`
`said surface layer.(cid:148) (Ex. 1001 at cl. 1) (emphasis added). This feature is not
`
`found in the provisional application. The only annealing discussed in the
`
`provisional application is performed on a single, photoluminescent silicon sample,
`
`laser processed in air, at a temperature of 1300 K (Ex. 1003 at 16:9-16, 17:12-13;
`
`18:12-19; Ex. 1012 at ¶ 33). This annealing procedure is not done for the purpose
`
`of enhancing the charge carrier density, and thereby the silicon(cid:146)s electrical
`
`7
`
`

`

`Docket No.: 685399-18IPR
`
`properties, but instead focuses on manipulating its optical properties to achieve a
`
`designed luminescence wavelength. (Ex. 1012 at ¶ 33). There is no suggestion of
`
`charge carrier density enhancement intended to increase electrical performance,
`
`optical absorption, or any combination of these factors in photodetectors. (Id.).
`
`Moreover, the single temperature disclosed in the provisional application
`
`(1300 K) is higher than any temperature disclosed in the (cid:145)467 Patent (Ex. 1001 at
`
`10:54-65; Ex. 1012 at ¶ 34). In fact, the proposed temperature is inconsistent with
`
`the (cid:145)467 patent, which states that (cid:147)annealing a microstructured silicon wafer for a
`
`significant duration at a very elevated temperature can lead to a degradation of the
`
`below-band gap absorptance, and hence a degradation in the performance of a
`
`photodetector(cid:148) and (cid:147)annealing at too high a temperature and duration can lower
`
`the wafer(cid:146)s response to both visible and infrared wavelengths.(cid:148) (Ex. 1001 at 16:4-
`
`8; 17:42-44 (emphasis added); Ex. 1012 at ¶ 34).
`
`There is no suggestion in the provisional application to perform an annealing
`
`step that selects a time and temperature for the express purpose of enhancing
`
`charge carrier density consistent with the stated goals of the (cid:145)467 Patent, nor is
`
`there any teaching to vary the anneal temperature, which in the provisional
`
`application lies entirely outside of the optimal range taught by the (cid:145)467 Patent.
`
`(Ex. 1012 at ¶ 35). The first application claiming priority to the provisional
`
`application, U.S. Patent Application No. 10/155,429 (Ex. 1004), also confines
`
`8
`
`

`

`Docket No.: 685399-18IPR
`
`annealing to a single, high temperature of 1300 K and a study of
`
`photoluminescence properties. (Ex. 1004 at 16:7-14; 19:10-20:5; Ex. 1012 at
`
`¶ 36). No annealing procedure is described that enhances charge carrier density to
`
`improve the electrical properties of the substrate. (Ex. 1012 at ¶ 36).
`
`The concept of selective annealing for the stated purpose of enhancing
`
`charge carrier density to improve electrical properties of the substrate does not
`
`appear until the CIP, filed in September 2004, the disclosure of which is nearly
`
`identical to that of the (cid:145)467 Patent. (See e.g., Ex. 1005 at ¶¶ [68]-[70], [74], [92];
`
`Fig. 6; Ex. 1012 at ¶¶ 37-39). Indeed, one of the main purposes for filing the CIP
`
`appears to have been the introduction of the selective annealing step, particularly
`
`for light absorption. Accordingly, claim 1 of the (cid:145)467 Patent, and all of the claims
`
`depending therefrom, are entitled to an earliest effective filing date of September
`
`24, 2004. (Ex. 1012 at ¶¶ 40-41).
`
`C.
`
`Prosecution History of the (cid:145)467 Patent
`
`The application that led to the (cid:145)467 Patent was filed on May 10, 2010 and
`
`included twenty-one (21) claims (two independent). (Ex. 1002 at 69-71). A
`
`preliminary amendment was filed that same day cancelling the original claims and
`
`introducing new claims 22-50. (Id. at 1-6). Independent claim 43 corresponds to
`
`issued claim 1 of the (cid:145)467 Patent. In response to a restriction requirement, the
`
`9
`
`

`

`Docket No.: 685399-18IPR
`
`applicant elected claims 43-50, and added three additional dependent claims. (Id.
`
`at 107-110). The claims were allowed without a rejection. (Id. at 114-120).
`
`Both Wu Thesis and Wu Article were cited to the Examiner in an August 13,
`
`2010 information disclosure statement by the applicant, although no copies were
`
`submitted. (Id. at 87-88). While Wu Thesis and Wu Article are deemed to have
`
`been considered by the Examiner, both documents are presented herein in a new
`
`light. First, there is no evidence that the Examiner considered Wu Thesis or Wu
`
`Article to qualify as prior art to the (cid:145)467 Patent because there is no explicit
`
`determination of a priority date for the examined claims. In the present Petition,
`
`Wu Thesis and Wu Article are both presented as prior art references under 35
`
`U.S.C. § 102(b), which would not have been possible during the original
`
`examination without an express finding that the claims were unsupported by the
`
`provisional application.
`
`Second, Wu Thesis and Wu Article are each being combined herein with
`
`references which were not previously before the Examiner. For example, as
`
`explained in more detail below, Gibbons is presented for its teachings regarding
`
`the effects of annealing on charge carrier density in doped silicon. There is no
`
`evidence that any reference qualifying as prior art before the Examiner specifically
`
`taught annealing for the purpose of charge carrier density enhancement to improve
`
`10
`
`

`

`Docket No.: 685399-18IPR
`
`electrical properties. Thus, the grounds of rejection presented herein are not the
`
`same or substantially the same as any ground previously considered by the Office.
`
`D.
`
`One of Ordinary Skill in the Art
`
`A person of ordinary skill in the art of the (cid:145)467 Patent at the time of the
`
`alleged invention (which, as described above, would have had a priority date of
`
`September 24, 2004) would have had at least a bachelor(cid:146)s degree in material
`
`science, physics, electrical engineering, or a similar degree, or equivalent training
`
`and experience, and have at least one year of work experience in the fields of
`
`optoelectronic devices or semiconductor processing. (Ex. 1012 at ¶¶ 23-24).
`
`E.
`
`Claim Construction
`
`The terms of claims in the (cid:145)467 Patent are to be given their broadest
`
`reasonable interpretation in light of the specification, as understood by one of
`
`ordinary skill in the art. 37 C.F.R. § 42.100(b). For purposes of this Petition only,
`
`Petitioner submits that the terms and phrases in the challenged claims are entitled
`
`to their plain and ordinary meaning, and as such, no detailed constructions are
`
`proposed therefor. Petitioner(cid:146)s positions herein are without prejudice to any other
`
`claim construction Petitioner may advance in this or another administrative
`
`proceeding before the Patent Trial and Appeal Board or other agency, or before the
`
`district court.
`
`11
`
`

`

`Docket No.: 685399-18IPR
`
`V.
`
`THERE IS A REASONABLE LIKELIHOOD THAT PETITIONER
`WILL PREVAIL WITH RESPECT TO AT LEAST ONE
`CHALLENGED CLAIM OF THE (cid:145)467 PATENT
`
`The subject matter of the challenged claims of the (cid:145)467 Patent is disclosed
`
`and taught in the prior art as explained below. The references and combinations
`
`utilized in the below grounds of rejection render obvious each of claims 1-3 and 6-
`
`8, and provide a reasonable likelihood that the Petitioner will prevail with respect
`
`to at least one claim. 35 U.S.C. § 314(a).
`
`A.
`
`Prior Art
`
`1. Wu Thesis
`
`a. Wu Thesis is at Least a June 2001 Printed Publication
`Under 35 U.S.C. § 102(b)
`To qualify as a prior art printed publication, a document must have been
`
`(cid:147)disseminated or otherwise made available to the extent that persons interested and
`
`ordinarily skilled in the subject matter or art exercising reasonable diligence, can
`
`locate it.(cid:148) Kyocera Wireless Corp. v. Int(cid:146)l Trade Comm(cid:146)n, 545 F.3d 1340, 1350
`
`(Fed. Cir. 2008) (internal quotations and citations omitted). Unlike circumstances
`
`in which a thesis is only found through a single university library, Wu Thesis was
`
`made widely publicly available at least as early as June 2001 through a commercial
`
`storage and publication service that specializes in distributing dissertations to
`
`researchers in the relevant field.
`
`12
`
`

`

`Docket No.: 685399-18IPR
`
`(cid:147)Dissertation Abstracts International(cid:148) ((cid:147)DAI(cid:148)) is a monthly publication that
`
`includes abstracts of doctoral dissertations submitted to UMI Company by
`
`participating institutions, one of which is Harvard University. (Ex. 1010 at 6, 14).
`
`UMI(cid:146)s (cid:147)Dissertation Services(cid:148) is provided as a (cid:147)program of publishing,
`
`bibliographic, and copy services which enables the researcher to locate doctoral
`
`dissertations, and to acquire copies of those manuscripts published by UMI.(cid:148) (Id.
`
`at 7). Entries are grouped alphabetically by author in subject categories. (Id. at 6).
`
`In Section B, which includes dissertations within (cid:147)The Sciences and Engineering,(cid:148)
`
`there is a category listing of Physical Sciences/Physics/Optics. (Id. at 6, 11).
`
`Critically, the DAI provides detailed instructions on how to order copies of
`
`dissertations. (Id. at 9). (cid:147)Dissertations and master(cid:146)s theses available from UMI
`
`Company are indicated by an order number at the end of the entry.(cid:148) (Id.). Copies
`
`are printed on-demand in response to an order and payment. (Id.).
`
`In the June 2001 edition of DAI Section B, an abstract for Wu Thesis
`
`appears under the Physics, Optics category. (Id. at 20). Directly beneath the title
`
`and author information for Wu Thesis, (cid:147)Order Number DA9999758(cid:148) appears in
`
`bold print. (Id.). Accordingly, Wu Thesis was available for purchase from the
`
`UMI Company at least as early as June 2001. This is further confirmed by Patent
`
`Owner(cid:146)s own admission in Harvard(cid:146)s on-line library catalog entry for Wu Thesis,
`
`which lists (cid:147)2001(cid:148) as the year published. (Ex. 1011). For at least these reasons,
`
`13
`
`

`

`Docket No.: 685399-18IPR
`
`Wu Thesis is a printed publication under 35 U.S.C. § 102(b), with a publication
`
`date at least as early as June 2001, well over a year before the actual September 24,
`
`2004 priority date of the (cid:145)467 Patent.
`
`The Teachings of Wu Thesis
`b.
`Wu Thesis is directed generally to two sets of experiments involving the
`
`irradiation of material by femtosecond laser pulses. Of interest to this proceeding
`
`are the first set of experiments, which examine (cid:147)the interaction of femtosecond
`
`laser pulses with silicon in the environment of a halogen-containing gas.(cid:148) (Ex.
`
`1006 at exhibit p. 4 (Abstract); Ex. 1012 at ¶ 43). Wu Thesis teaches the same
`
`laser-irradiation methodology for creating microstructures on a silicon surface as
`
`the (cid:145)467 Patent. For example, Wu Thesis utilizes a regeneratively amplified
`
`titanium-sapphire ((cid:147)Ti:sapphire(cid:148)) laser system that produces 100-femtosecond
`
`laser pulses of 800 nm wavelength at a rate of 1 kHz. (Compare Ex. 1006 at 5 with
`
`Ex. 1001 at 6:64-67; Ex. 1012 at ¶ 44). Also consistent with the (cid:145)467 Patent, Wu
`
`Thesis teaches the effects of varying laser parameters and ambient gas on the
`
`resulting morphology of the silicon microstructures. For example, Wu Thesis finds
`
`that sharp spikes are formed only in SF6 and Cl2, and that spike heights and
`
`distances are impacted by variations in pulse duration and fluence. (See Ex. 1006
`
`at 7, 10-12; Ex. 1001 at 8:41-44; 9:6-10, 29-34; Ex. 1012 at ¶ 45).
`
`14
`
`

`

`Docket No.: 685399-18IPR
`
`More critically, Wu Thesis describes various chemical analyses, including
`
`Secondary Ion Mass Spectrometry ((cid:147)SIMS(cid:148)), on spikes formed in SF6 gas. SIMS
`
`is used to analyze the composition of a surface, enabling one to identify elements
`
`present therein and identify a doping profile. (Ex. 1012 at ¶ 13). Wu Thesis notes
`
`that while certain element concentrations, such as that of oxygen, are comparable
`
`to that of untreated silicon, the spikes exhibit (cid:147)very high concentrations of sulfur
`
`and fluorine.(cid:148) (Ex. 1006 at 17; Ex. 1012 at ¶ 46). Wu Thesis theorizes that these
`
`results may be from a dissociation of the SF6 gas present during the laser
`
`irradiation. (Ex. 1006 at 17-18; Ex. 1012 at ¶ 46).
`
`The gas plays an essential role in forming sharp spikes.
`Without a gas that etches silicon, blunt irregular structures are
`formed. The addition of a plasma etchant such as SF6 sharpens
`the structures and creates a more regular pattern. Therefore, the
`gas must be involved in sharpening the spikes.
`
`(Ex. 1006 at 35).
`
`Wu Thesis thereafter recognizes that, although the spikes may aid in the
`
`increased absorption observed in the microstructured silicon, the introduction of
`
`these sulfur impurities can also act as (cid:147)infrared absorbing centers.(cid:148) (Ex. 1006 at
`
`50-51; Ex. 1012 at ¶ 46). To test this theory, Wu Thesis describes a vacuum
`
`anneal of the sample having 10-12 (cid:181)m high spikes at 1210 K for three hours.
`
`Chemical analysis shows that the sulfur content in the spikes is decreased after the
`
`15
`
`

`

`Docket No.: 685399-18IPR
`
`anneal procedure. (Ex. 1006 at 52). The result is a decrease in the absorptance of
`
`the silicon in the infrared range to near the levels of untreated silicon, while visible
`
`wavelength absorption remained relatively unchanged. (Id. at 55).
`
`Wu Thesis concludes that the enhanced absorption properties in both visible
`
`and infrared spectra (cid:147)could have important technological applications.(cid:148) (Id. at 60).
`
`For example, Wu Thesis proclaims that the techniques applied to the silicon
`
`samples therein could serve to (cid:147)enhance the efficiency of existing photovoltaic
`
`devices in the visible range,(cid:148) and further (cid:147)extend the wavelength range of existing
`
`photovoltaic devices.(cid:148) (Id. at 126; Ex. 1012 at ¶ 47). Thus, Wu Thesis and the
`
`(cid:145)467 Patent share this common goal (cid:150) i.e., improvement in the ability of a silicon
`
`photodetector to detect radiation in a wide wavelength range through the
`
`incorporation of dopants into the silicon surface through pulsed laser processing.
`
`(Ex. 1001 at 1:27-31; Ex. 1012 at ¶ 47).
`
`2.
`
`Gibbons
`
`Gibbons was published in September 1972 as part of volume 60 of the
`
`Proceedings of the IEEE. Accordingly, Gibbons was published more than one year
`
`before the proper September 24, 2004 priority date of the (cid:145)467 patent, and is
`
`therefore prior art under 35 U.S.C. § 102(b). Gibbons is directed to the use of
`
`annealing to repair damage to semiconductor material and to activate dopant
`
`16
`
`

`

`Docket No.: 685399-18IPR
`
`materials following an ion implantation process (which is an alternative form of
`
`doping). (Ex. 1007 at 1083; Ex. 1012 at ¶¶ 12, 48).
`
`Gibbons examines the effects of several parameters, including implant dose,
`
`anneal time, and anneal temperature, that affect the electrical characteristics of
`
`semiconductor material after ion implantation and annealing. (Ex. 1007 at 1089-
`
`92; Ex. 1012 at ¶ 49). While the discussion is primarily directed to the
`
`implantation of boron, a p-type dopant in silicon, the conclusions are generally
`
`applicable for practical a