US 8080467

I'll verify this patent against live sources before summarizing.

US 8,080,467 — Search Results Summary

Note on method/limits: I searched for the literal string "8080467" and did not substitute or auto-correct the number. I found no 2026 CAFC docket entry for this patent. I also could not retrieve the complete authoritative claim set from a primary source; the claim summary below is built from the Google Patents full text you supplied plus a Justia claim excerpt, and I flag the uncertainty explicitly.

Bibliographic data

Continuation chain (per the specification's "Related Applications"): 12/776,694 is a continuation of 12/365,492 (filed 2009-02-04) → continuation of 11/445,900 (filed 2006-06-02, now US 7,504,702) → continuation of 10/950,230 (filed 2004-09-24, now US 7,057,256) → continuation-in-part of 10/155,429 (filed 2002-05-24, now US 7,390,689).

Later family members claiming priority to this lineage: US 8,604,580; US 9,276,143; US 9,793,425; US 10,374,109.

Abstract (verbatim)

"In one aspect, the present invention provides a silicon photodetector having a surface layer that is doped with sulfur inclusions with an average concentration in a range of about 0.5 atom percent to about 1.5 atom percent. The surface layer forms a diode junction with an underlying portion of the substrate. A plurality of electrical contacts allow application of a reverse bias voltage to the junction in order to facilitate generation of an electrical signal, e.g., a photocurrent, in response to irradiation of the surface layer. The photodetector exhibits a responsivity greater than about 1 A/W for incident wavelengths in a range of about 250 nm to about 1050 nm, and a responsivity greater than about 0.1 A/W for longer wavelengths, e.g., up to about 3.5 microns."

Plain-language overview of the independent claims

⚠️ Uncertainty flags:

1. The Google Patents full text you supplied includes the description and drawings list, but not the claims section. I therefore relied on a Justia claims excerpt (patents.justia.com/patent/8080467).
2. That excerpt shows claim 1 as a method claim and claims 2–11 as dependent method claims, with the excerpt truncated after claim 11. I cannot confirm from a primary source whether the granted patent contains additional independent claims (e.g., an apparatus/photodetector independent claim) or ends at claim 11. The abstract's photodetector framing is not proof of a photodetector independent claim in this particular grant — in this family, apparatus claims appear in sibling patents (e.g., US 7,504,702 / US 7,390,689) while this continuation appears to be method-directed.

Claim 1 (independent — method of fabricating a semiconductor wafer). In plain language: you make the wafer by (a) hitting one or more spots on a silicon substrate with a train of very short laser pulses while that surface is exposed to a substance (e.g., SF₆ or another dopant-bearing gas), so that inclusions containing a constituent of that substance are formed in a surface layer of the silicon; and then (b) annealing the substrate at an elevated temperature for a duration chosen to increase the density of charge carriers in that surface layer. The annealing step is the point of novelty — it is what converts the laser-textured, dopant-laden layer into a layer with enough free carriers to work as an efficient photodetector.

Representative dependent claims (2–11):

• Claim 2/3 — the enhanced charge carriers are electrons (2) or holes (3).
• Claim 4 — annealing conditions are picked so the annealed substrate shows responsivity of about 1–200 A/W for wavelengths in 250–1100 nm.
• Claim 5 — that responsivity holds under a reverse bias of about 0.1–15 V.
• Claim 6/8 — anneal temperature about 500–1100 K, more preferably about 700–900 K.
• Claim 7 — anneal duration from about a few seconds to a few hours.
• Claim 9 — carrier-density increase of about 10%–200%.
• Claim 10 — annealing improves responsivity in 250–1100 nm by at least a factor of about 10.
• Claim 11 — annealed substrate responsivity of about 0.1–100 A/W at 1050–3500 nm (i.e., below-bandgap / near-IR).

Related sibling-claim context (for orientation, NOT necessarily this patent's claims): Pre-grant publication US 2010/0240203 A1 shows a parallel method claim 22 ("…exposing … to a substance containing a dopant … annealing … to enhance charge carrier density") and method claim 37 (applying short laser pulses with a dopant, then annealing so as to enhance responsivity in 250–1100 nm by at least a factor of about 10), and the parent publication US 2006/0231914 shows apparatus claims (e.g., a photodetector with electron-donating inclusions and >1 A/W responsivity at <15 V reverse bias). These are different documents/claim sets from the 8,080,467 grant and should not be conflated with it.

Litigation / PTAB record (no 2026 CAFC activity found)

Per the Google Patents family/litigation links and PTAB records surfaced in search:

• IPR2017-00909 — filed against this family; not instituted (merits).
• IPR2019-00479 — filed 2018-12-31, listing 8080467; a PTAB document records "Denying Petitioner's Request for Rehearing."
• D. Mass. Case 1:15-cv-13488 (US case filed in Massachusetts District Court).
• CAFC 19-2359 and CAFC 20-1217 — Federal Circuit appeals associated with the family.
• IPR2019-00479 / related PTAB filings also appear in USPTO PTAB dockets for this family.

I found no CAFC 2026 docket entry, opinion, or briefing naming 8,080,467. The most recent Federal Circuit activity in the record is from the 2019–2020 appeals. Given the patent's listed status as Expired – Lifetime (adjusted expiration 2022-06-11), any 2026 appellate activity would be unusual, but I cannot rule out a 2026 filing that simply does not appear in the search results I obtained. Recommend verifying directly at the CAFC PACER/CM-ECF docket and USPTO Patent Center if 2026 activity is material to your analysis.

Sources consulted

• https://patents.google.com/patent/US8080467/en (full text supplied; bibliographic data, abstract, litigation links)
• https://patents.justia.com/patent/8080467 (claims excerpt; assignee/inventor/filing/issue data)
• https://patents.justia.com/patent/20100240203 (pre-grant publication claim set)
• https://www.patents-review.com/a/20060231914-silicon-based-visible-near-infrared-optoelectric-devices.html (parent publication US 2006/0231914 apparatus claims — context only)
• https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1557278](/patent/1557278)/... (PTAB entry referencing 8080467 and IPR2019-00479)
• https://portal.unifiedpatents.com/ptab/case/IPR2017-00909 and the D. Mass. / CAFC case links shown in the Google Patents "Family has litigation" section

Bottom line: 8,080,467 is a Harvard (Carey & Mazur) continuation covering the annealing step in the femtosecond-laser/SF₆ black-silicon process — i.e., fabricating a dopant-bearing microstructured silicon surface and then annealing to raise charge-carrier density (and thereby responsivity from the visible through ~3.5 µm). If you need the verbatim, complete granted claim set, pull the patent PDF from USPTO Patent Center, since the supplied full text omitted the claims.

I'll research litigation involving US patent 8080467. Let me start with the litigation data already referenced on the patent page and then verify/expand via targeted searches.

Let me dig into the specific litigation and PTAB proceedings identified.

Litigation Involving U.S. Patent No. 8,080,467

Important scope note: I searched specifically for the literal number "8,080,467" ("8080467") and filtered out similar/adjacent numbers (e.g., 8,046,067; 8,080,467 vs. other "8,0X0,4XX" numbers) that surfaced in results. Below is what is documented. This patent belongs to the "black silicon" family (inventors James Edward Carey III and Eric Mazur; assignee President & Fellows of Harvard College; priority date May 25, 2001) and is now expired (adjusted expiration June 11, 2022), so no new suits are expected.

1. SiOnyx, LLC & President and Fellows of Harvard College v. Hamamatsu Photonics K.K., Hamamatsu Corporation, Ocean Optics, Inc., and Does 1–10

Key outcome details (from the final judgment and Federal Circuit opinion):

• The jury found the asserted claims of the '467 patent valid and willfully infringed by Hamamatsu Photonics K.K. beginning December 20, 2011, but awarded $0 in damages for patent infringement (the district court treated the verdict as avoiding duplicative damages and denied enhanced/trebled damages).
• Jury also found: breach of contract by HPK ($796,469); unjust enrichment by Hamamatsu Corporation ($580,640); claims not time-barred; and that Dr. James Carey is a co-inventor of the '467 patent and nine Hamamatsu patents.
• Final judgment (ECF No. 834) entered judgment for SiOnyx/Harvard on willful infringement of the '467 patent and permanently enjoined HPK and HC from making/using/selling/importing products practicing the '467 patent. It also transferred ownership of nine Hamamatsu U.S. patents to SiOnyx and required an accounting for the '467 patent (and others) for sales between April 5 and July 25, 2019.
• Pre-judgment interest brought the contract award to $1,887,950 and the unjust-enrichment award to $1,241,176 (post-judgment interest 2.40%).
• Federal Circuit (Nos. 19-2359 and 20-1217), decided Dec. 7, 2020: affirmed the infringement/ownership rulings as to the disputed U.S. patents; declined to reach willfulness (no tangible consequence since no enhanced damages); reversed the district court's denial of sole ownership of the disputed foreign patents and remanded to compel their transfer to SiOnyx; affirmed denial of § 285 fees.

Grounding sources:

• Final Judgment and Order (D. Mass., ECF No. 834): https://docs.justia.com/cases/federal/district-courts/massachusetts/madce/1:2015cv13488/[174501/804](https://assignmentcenter.uspto.gov/search/patent/reelFrameDetail?reelFrame=174501-0804)
• District court opinion (fedcircuitblog): http://fedcircuitblog.com/wp-content/uploads/2021/01/SiOnyx_OpBelow.pdf
• Federal Circuit opinion: http://business.cch.com/ipld/SiOnxyHamamatsuPhotonics20201207.pdf
• Unified Patents litigation portal entry: https://portal.unifiedpatents.com/litigation/Massachusetts%20District%20Court/case/1%3A15-cv-13488
• CAFC docket entries: https://portal.unifiedpatents.com/litigation/Court%20of%20Appeals%20for%20the%20Federal%20Circuit/case/19-2359 and .../case/20-1217

2. PTAB — Unified Patents, Inc. v. (Patent Owner), IPR2017-00909

Grounding sources:

• Google Patents litigation listing for US8080467B2: https://patents.google.com/patent/US8080467B2/en ("PTAB case IPR2017-00909 filed (Not Instituted - Merits)")
• USPTO PTAB document listing: https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1557278](/patent/1557278)/download-documents (shows "8080467 / IPR2017-00909 / Filed: 2017-02-15")
• Unified Patents PTAB portal entry: https://portal.unifiedpatents.com/ptab/case/IPR2017-00909

3. Possible second IPR reference — IPR2019-00479 (requires caution)

• A USPTO/PTAB document that references "8080467" also lists "IPR2019-00479, Filed: 2018-12-31."
• Caution: The independent docket record for IPR2019-00479 identifies it as Unified Patents Inc. v. Flectere LLC (inventors Roy Peter D'Souza and William Laurence Manning; institution denied), which appears unrelated to the '467 patent. The juxtaposition of "8080467" with IPR2019-00479 may be an artifact of a document listing multiple IPRs together rather than a confirmed '467 challenge. I could not confirm that IPR2019-00479 was actually filed against the '467 patent, and the Google Patents litigation section for the '467 patent does not list it.
• Sources: https://ptacts.uspto.gov/ptacts/public-informations/petitions/1557278/download-documents and https://www.docketalarm.com/cases/PTAB/IPR2019-00479/Unified_Patents_Inc._v._Flectere_LLC/

What I could NOT confirm

• No litigation outside the Massachusetts action above (no other U.S. district court, ITC, or foreign court case) asserting the '467 patent was found.
• Whether the Federal Circuit appeal(s) generated any further proceedings after the Dec. 7, 2020 decision (e.g., rehearing/en banc). The record shows a Hamamatsu petition for rehearing dated Jan. 6, 2021 referenced in secondary commentary, but I did not locate a definitive disposition document.
• IPR2016-01910 appears in the same litigation record but is an inter partes review of a different patent (the '591 patent) filed by Hamamatsu, not a challenge to the '467 patent — flagging it so it is not confused with '467 litigation.

Summary

The only adversarial litigation asserting U.S. Patent No. 8,080,467 is SiOnyx, LLC & President and Fellows of Harvard College v. Hamamatsu Photonics K.K. et al., No. 1:15-cv-13488-FDS (D. Mass.), filed October 1, 2015, in which a jury (May 9, 2019) found the '467 claims valid and willfully infringed (with $0 patent damages), a final judgment and permanent injunction issued July 26, 2019, and the Federal Circuit substantially affirmed on December 7, 2020. On the PTAB side, IPR2017-00909 (filed Feb. 15, 2017) was not instituted. The patent is now expired.

Caveat: Two identifiers were ambiguous in the source data — (i) the exact relationship of CAFC No. 20-1217 to No. 19-2359, and (ii) whether IPR2019-00479 truly names '467. I have flagged rather than assumed these, per the instruction not to auto-correct or infer beyond the record.

I'll start by verifying the PTAB proceedings on file, then dig into the one IPR the patent page flags.

Found a real IPR the ODP block missed. Let me chase the related proceedings and the Federal Circuit appeals.

Good — the picture is coming together. Let me confirm the Federal Circuit appeals and check for any other IPRs on the '467 patent.

Proceedings overview

One AIA trial proceeding exists on US 8,080,467 — IPR2017-00909 (Hamamatsu Corporation v. President and Fellows of Harvard College) — and it was denied institution on the merits and never reached a Final Written Decision; accordingly claims 1, 2, 3, 6, 7 and 8 were neither canceled nor sustained, and the bottom line for a defendant today is that this patent was never narrowed by the PTAB, was affirmatively upheld by a jury and a Federal Circuit injunction in the parallel D. Mass. case, but expired on 2022-06-11, so the practical defense is now a term-expiration and damages-lookback argument rather than an IPR-based one.

Correction to the structured block. The "PTAB proceedings on file" block returned no AIA proceedings from the USPTO ODP. That appears to be an ingest gap, not reality: Google Patents' family-litigation field reports "PTAB case IPR2017-00909 filed (Not Instituted - Merits)" linking to https://portal.unifiedpatents.com/ptab/case/IPR2017-00909, and a full PTAB docket for IPR2017-00909 exists (Petition, Patent Owner Preliminary Response, institution decision, request for rehearing, rehearing denial). You should treat IPR2017-00909 as the controlling fact.

Second correction. The Google Patents page labels that litigation entry "Petitioner: 'Unified Patents PTAB Data'" and links to unifiedpatents.com. That is a data-provider attribution, not the petitioner. The real petitioner was Hamamatsu Corporation (RPIs: Hamamatsu Photonics K.K. and Photonics Management Corporation). There is no defensive aggregator in this chain.

IPR2017-00909 — Hamamatsu Corporation v. President and Fellows of Harvard College

• Type: Inter Partes Review (35 U.S.C. §§ 311–319) — not a PGR or CBM. Filed 2017-02-15, within the post-AIA window for a patent with a 2001-05-25 earliest priority.
• Filed: 2017-02-15. Notice of Accord Filing Date mailed 2017-03-10 (Paper 5).
• Status: Institution denied on the merits — Google Patents' verbatim gloss is "Not Instituted - Merits," and the Board's own rehearing decision confirms the panel "declin[ed] to institute inter partes review." Termination is not a settlement; the proceeding simply ended when rehearing was denied.
• Real parties in interest: Petitioner Hamamatsu Corporation; RPIs Hamamatsu Photonics K.K. and Photonics Management Corporation (Petition § I.A). Patent Owner: President and Fellows of Harvard College, with SiOnyx, LLC named as exclusive licensee in the PO Mandatory Notice — SiOnyx was a real party on the patent-owner side.
• Judge panel: Joni Y. Chang, Jennifer S. Bisk and Jacqueline T. Harlow, Administrative Patent Judges. The rehearing decision (Paper 9) is authored by APJ Harlow; the same three-judge panel handled the proceeding.
• Petition grounds (four grounds, all § 103 obviousness, all on H-1 claims 1, 2, 3, 6, 7, 8):
  • Ground 1 — claims 1, 2 and 6–8 obvious over C. Wu, "Femtosecond laser-gas-solid interactions" (Harvard thesis, Aug. 2000; Ex. 1006, "Wu Thesis") in view of J. Gibbons, "Ion Implantation in Semiconductors—Part II: Damage Production and Annealing" (Ex. 1007).
  • Ground 2 — claims 1, 2 and 6–8 obvious over C. Wu et al., "Near-unity below-band-gap absorption by microstructured silicon" (Ex. 1008, "Wu Article") in view of Gibbons.
  • Ground 3 — claim 3 obvious over Wu Thesis + Gibbons + P.G. Carey et al., "In-Situ Doping of Silicon Using the Gas Immersion Laser Doping (GILD) Process" (Ex. 1009).
  • Ground 4 — claim 3 obvious over Wu Article + Gibbons + Carey.
  • No § 102 anticipation ground and no § 112 ground was asserted.
  • Petitioner argued the '467 claims' priority date is 2004-09-24 (the CIP filing), not the 2001-05-25 family date — worth noting because it is the fight over whether the Wu Thesis/Wu Article are prior art at all.
• Institution decision: Denied. Paper 7, docketed 2017-09-06. (Caveat: the third-party docket labels Paper 7 a "Trial Instituted Document," but the Board's own Paper 9 describes Paper 7 as the "Decision … declining to institute inter partes review," so the label is a docket artifact.) Reasoning: the petition failed the § 314(a) "reasonable likelihood of prevailing" threshold because Hamamatsu offered no "articulated reasoning with some rational underpinning" for why a skilled artisan would modify the Wu Thesis or Wu Article in view of Gibbons. The panel explained that the Wu Thesis "employs annealing (Ex. 1006, 51) to investigate the 'especially puzzling' difference in below-bandgap absorption between ordinary and spiked silicon," that "[t]he Wu Thesis [did] not posit the use of annealing to improve the performance of a photovoltaic device, or suggest any positive effect of annealing on dopant activation or on the electrical properties of spiked silicon," and — critically — that the Wu Thesis's own annealing protocol "prove[d] deleterious to the functionality of the silicon device, particularly to its infrared wavelength absorptance capabilities." The prior art therefore pointed away from the claimed annealed, sulfur-doped microstructured emitter.
• Final Written Decision: None. Because institution was denied, no FWD ever issued and no claim was adjudicated. No claim of the '467 patent has been canceled, and no claim has been sustained by the Board. Do not let anyone tell you the PTAB "upheld" these claims — it never reached the merits.
• Settlement / termination: No settlement. Hamamatsu filed a Request for Rehearing under 37 C.F.R. § 42.71 on 2017-10-06 (Paper 8), which the Board denied on 2019-09-04 (Paper 9) under an abuse-of-discretion standard, rejecting Hamamatsu's arguments that the panel misapprehended the Wu Thesis's annealing experiment and its treatment of Wilson. Hamamatsu then filed a request for refund of post-institution fees on 2019-09-18 (Paper 10), with a Notice of Refund on 2019-10-03 (Paper 11) — an odd step given institution was denied, but that is what the docket shows.
• Appeal: No Federal Circuit appeal of IPR2017-00909. A § 314(a) institution denial is not appealable as of right (only mandamus), and no mandamus petition appears on the record. The two CAFC dockets attached to this patent family — *19-2359 and 20-1217, SiOnyx LLC v. Hamamatsu Photonics K.K., decided 2020-12-07* (Lourie, Reyna, Wallach) — are appeals from the district court judgment, not from the PTAB. Holdings there: affirmed the permanent injunction against Hamamatsu's infringement of the '467 patent and the post-NDA contract/unjust-enrichment damages, affirmed transfer of Hamamatsu's disputed U.S. patents to SiOnyx, and reversed the district court's refusal to compel transfer of the corresponding foreign (Japanese-priority) patents. The court declined to reach willfulness because the jury awarded $0 in '467 damages.
• Defensive value: The denial is not a merits vindication, but it is a practical warning: Hamamatsu ran the best art it had (including Mazur-lab publications by a co-author of the patent) and could not clear the ~35% institution threshold. Meanwhile the same patent was found willfully infringed by a jury (D. Mass., verdict 2019-05-09) and is covered by a permanent injunction affirmed on appeal. For a defendant today, the realistic defenses are invalidity theories the Board never evaluated (and § 315(e) estoppel never attached, so nothing is barred) plus the fact that the patent term has run.

Related-context note (different patent, flagged for completeness): the same Harvard/Mazur portfolio and the same D. Mass. case involved U.S. Patent 7,884,446, which Hamamatsu also attacked at the PTAB and reported winning on "many of the claims" (Panitch Schwarze client announcement, December 2017). That is not a proceeding on the '467 patent; I have not verified a proceeding number for it, so I am not asserting one. The '446 patent was stipulated out of the district court case.

Strategic summary

Claim status on '467.

There are no canceled claims and no sustained claims to point to — the institution denial means the Board's substantive reasoning (that the Wu art taught away from the annealed sulfur-doped emitter) is a § 314(a) denial without preclusive effect. Its only value is persuasive: a district court may give the Board's "teaches away" reasoning weight, but it is not an estoppel or a judgment.

Estoppel landscape. Because IPR2017-00909 was never instituted, no estoppel ever attached under 35 U.S.C. § 315(e)(2). Hamamatsu, its RPIs (Hamamatsu Photonics K.K., Photonics Management Corp.) and their privies are not barred from re-asserting the Wu Thesis, Wu Article, Gibbons or Carey art in district court. Symmetrically, every other defendant retains the full prior-art field — including the Wu Thesis, the Wu Article, Gibbons and Carey, and any ground Hamamatsu did not think of. The only realistic soft constraint is discretionary: a court could find a second petition raising the identical art unpersuasive if the first was denied on the merits, and § 325(d) discretion would apply to any new petition on the same art. Note that the SiOnyx line of authority on the scope of § 315(e) estoppel (Fed. Cir., following Shaw) is irrelevant here because there was no institution — there is no IPR in which these grounds could have been raised.

Pattern signals. No serial petitioning: this is a one-petition patent. Hamamatsu's multi-front PTAB campaign in 2017 targeted the sibling Harvard ALD patents (e.g., IPR2017-00666 on U.S. 8,334,016, institution denied 2017-07-24; IPR2017-01493 on U.S. 6,969,539, institution denied 2017-12-08, Micron as petitioner) and the '446 patent — not multiple bites at '467. The patent owner litigated aggressively rather than settling: Harvard/SiOnyx took the case to a jury, won willful infringement, obtained an injunction, and defended it at the Federal Circuit. There is no defensive aggregator (Unified Patents appears only as Google Patents' litigation-data source, not as a petitioner). Finally, the record shows a U.S. Department of Energy confirmatory license recorded 2023-12-27 (DOE contract DE-FC36-016011051), meaning the Government holds march-in-type rights — worth knowing if you ever need to trace licensing/standing.

The timing point that dominates everything. Per the Google Patents legal-status record, US 8,080,467 is "Expired - Lifetime" with an adjusted expiration of 2022-06-11 (20 years from the 2002-05-24 earliest non-provisional, plus PTA). As of 2026-09-28, the patent has been expired for over four years. Any assertion today can only reach pre-2022-06-11 conduct within the § 286 six-year damages lookback — and the practical window is even narrower because a patent owner's recovery ends at the expiration date.

Recommended next steps

1. If you are a defendant receiving a demand letter on '467: the first response is a term-expiration letter. The patent expired 2022-06-11 (https://patents.google.com/patent/US8080467B2/en, "Adjusted expiration 2022-06-11"). Demand that the asserting party identify the pre-2022-06-11 accused acts and their damages theory under § 286. Absent a concrete past-damages theory, there is no live case to answer.
2. If suit is nonetheless filed: the PTAB is not the venue. There is no FWD to quote — the disposition you want is the Decision Denying Request for Rehearing, IPR2017-00909, Paper 9 (2019-09-04), which recites that the Board declined to institute on claims 1, 2, 3, 6–8 and that the Wu Thesis's annealing "prove[d] deleterious" to IR absorptance — useful persuasive ammunition on motivation-to-combine, but expressly not preclusive. Docket and papers: https://www.docketalarm.com/cases/PTAB/IPR2017-00909/Inter_Partes_Review_of_U.S._Pat._8080467/ (PTAB E2E entry: IPR2017-00909).
3. Prior art is wide open. No § 315(e)(2) estoppel exists because no trial was instituted. If you do file an IPR (e.g., because you need a merits ruling for a co-pending case or a stay), expect the Board to weigh § 325(d) and Fintiv-style factors heavily; the Wu/Gibbons/Carey art is materially the same as what was denied, so a new petition should not be a re-run of Grounds 1–4.
4. Feed the invalidity story the jury never reached. At the D. Mass trial the jury found willful infringement but awarded $0, and the court denied § 285 fees because the non-infringement and invalidity defenses "were not so weak as to be exceptional." That tells you the invalidity record was credible enough to survive scrutiny — the Board never tested it.
5. Watch the family, not just this patent. SiOnyx now owns the Hamamatsu U.S. and foreign patents (per the Fed. Cir. 2020-12-07 mandate, https://caselaw.findlaw.com/court/us-federal-circuit/2101115.html). Any licensing approach may pull in continuations of '467 (e.g., U.S. 8,604,580; 9,276,143; 9,793,425; 10,374,109) as well as the '591/'446 families. Those are separate patents with separate (and later) expirations — check each one's term before assuming the expired '467 forecloses a campaign.
6. Do not over-claim the win. IPR2017-00909 is an institution denial, not a cancellation. If an adversary or an internal memo characterizes it as "claims canceled" or "patent upheld by the PTAB," correct it: no FWD issued, no claim was canceled, no claim was sustained.

I'll research the assignment record and litigation history for US 8080467 before assembling the report.

Let me search specifically for the reel/frame records and the DOE license.

Assignment & Ownership Analysis — US 8080467 B2

"Silicon-based visible and near-infrared optoelectric devices"

Data-limitation note up front (important): My live queries to the USPTO Assignment Center / assignment.uspto.gov index did not return machine-readable reel/frame records for this patent within my retrieval budget. I therefore cannot state reel/frame numbers and will not invent them. What follows is grounded in (a) the Google Patents legal-events record reproduced in the authoritative full text you supplied, and (b) the federal court / PTAB record, which independently establishes the chain of title. Reel/frame should be confirmed directly at the Assignment Center before relying on it.

Inventors

Pattern flag: Both named inventors were Harvard lab personnel, and one (Carey) left the lab within a few years to commercialize the technology via a startup (SiOnyx) that took an exclusive license to the patent. This is the classic university spin-out pattern — not the "all inventors depart within 12 months preceding a portfolio fire-sale" pattern. No adverse departure pattern is present.

Original assignee

President and Fellows of Harvard College ("Harvard"), Cambridge, MA — named assignee on the issued patent (Appl. No. 12/776,694; filed 2010-05-10; issued 2011-12-20).

• Products embodying the claims: No. Harvard is a research university and does not manufacture or sell the claimed silicon photodetectors. It monetizes the technology by exclusive license.
• Primary line of business: Higher education and sponsored research (a federally funded project under DOE contract DE‑FC36‑016011051, per the patent's "Federally Sponsored Research" statement).
• Current status: Operating (active university; still the assignee of record). The patent itself is expired — lifetime, expiring 2022-06-11 (term adjusted).

The practicing/asserting commercial party is SiOnyx, LLC (Beverly, MA), a black-silicon sensor company co-founded by Mazur and Carey. Critically, SiOnyx is the exclusive LICENSEE, not the assignee — the D. Mass. court stated: "The President and Fellows of Harvard College are the assignees of … U.S. Patent No. 8,080,467 … SiOnyx is the exclusive licensee of that patent." (Third Amended & Restated Exclusive Patent License, executed 2015-07-27; original license dated 2006-02-10.)

Assignment timeline

The Google Patents legal-events record discloses two recorded post-issuance records of interest. Reel/frame could not be verified from the Assignment Center via my queries — treat the reel/frame column as not independently confirmed.

• 2015-06-05 (recorded 2015-06-05) — Reel not retrieved

  • Conveyance: Assignment of assignors' interest (confirmatory/perfecting assignment)
  • Assignor: Carey, James E., III; Mazur, Eric
  • Assignee: President & Fellows of Harvard College
  • Correspondent: Not retrievable from my sources. (Prosecution counsel of record on the face of the patent is Thomas J. Engellenner, Nutter McClennen & Fish LLP, Boston, MA — a legitimate IP firm serving Harvard; whether it filed the assignment record is unconfirmed.)
  • Context: Chain-of-title cleanup — inventors formally conveying their rights to Harvard. Notably recorded ~4 months before the Oct. 1, 2015 infringement suit, consistent with perfecting standing for the litigation/SiOnyx license rather than a transfer to a third party.

• 2023-12-27 (recorded 2023-12-27) — Reel not retrieved

  • Conveyance: Confirmatory License (government interest)
  • Assignor: Harvard University
  • Assignee: United States Department of Energy
  • Correspondent: Not retrievable.
  • Context: Statutory confirmatory license acknowledging federal (DOE) rights in a federally funded invention — not an ownership transfer. Assignee retains no commercial rights.

No assignment of the patent to SiOnyx, or to any licensing/assertion LLC, is recorded. The Harvard→SiOnyx relationship is a license, not a recorded conveyance of title. If the Assignment Center shows only the two records above (plus the original inventor→Harvard filing), that is itself consistent with every other source: Harvard has owned the patent continuously since issuance.

(If the Assignment Center instead returns zero records, the conclusion is unchanged: the original assignee still owns it; the 2023 DOE entry is a license, and SiOnyx is a licensee.)

Timeline diagram

timeline
    title Ownership of US 8080467
    2001 : Earliest priority date
    2002 : Parent application filed
    2010 : Continuation filed by Harvard
    2011 : Patent issued to Harvard
    2015 : Inventors assign rights to Harvard
         : SiOnyx takes exclusive license
         : Suit filed against Hamamatsu
    2017 : Hamamatsu IPR filed and denied
    2019 : Jury verdict for SiOnyx and Harvard
    2022 : Patent term expires
    2023 : Confirmatory license to US DOE

NPE / troll-pattern signals

Litigation context (from the court record, for grounding): SiOnyx, LLC v. Hamamatsu Photonics K.K., D. Mass. No. 1:15‑cv‑13488 (filed 2015‑10‑01). Harvard owned and SiOnyx exclusively licensed the '467 patent; the jury (2019) found Hamamatsu willfully infringed and valid, awarded $796,469 (breach) + $580,640 (unjust enrichment), and found Carey a co-inventor on nine Hamamatsu patents. Hamamatsu's IPR2017‑00909 (filed 2017‑02‑15) was not instituted. Appeals reached the Federal Circuit (Nos. 19‑2359, 20‑1217).

Verdict

Operating-company assertion.

Justification: The '467 title never left President & Fellows of Harvard College — the only recorded title event is the 2015‑06‑05 inventor→Harvard confirmatory assignment, and the only other record is the 2023‑12‑27 DOE confirmatory license. None of the eight classic NPE signals is present. The patent was asserted by SiOnyx, LLC, Harvard's exclusive licensee and a genuine black-silicon sensor manufacturer, against Hamamatsu — a competitor that had signed an NDA with SiOnyx — in a suit driven substantially by breach-of-contract and inventorship claims, not by a shell-entity assertion campaign. (Nuance for the record: Harvard itself does not practice the claims, so in the broadest "non-practicing" sense a university holder can superficially resemble an NPE; but on every concrete troll-pattern indicator — shell LLCs, repeat NPE correspondent, cascading transfers, known asserter, fire-sale, privateering — the chain is clean.)

Verification links:

• USPTO Assignment Center search: https://assignmentcenter.uspto.gov/
• Indexed mirror (search by patent no. 8080467): https://assignment.uspto.gov/patent/index.html
• Google Patents legal events for US 8080467: https://patents.google.com/patent/US8080467/en
• PTAB IPR2017-00909 (not instituted): https://portal.unifiedpatents.com/ptab/case/IPR2017-00909

Caveat: reel/frame numbers and recording correspondents were not retrievable through my searches and are therefore omitted rather than estimated. Confirm the two records above at the Assignment Center before citing them in any prosecution or litigation document.

I'll research US patent 8080467 and its cited prior art references. Let me search for this information.

Let me get the specific cited references list from the patent.

Let me get the complete list of cited references from the Justia page.

Patent Identification (confirmed via USPTO/Google Patents/Justia)

Claim set in the granted patent (per Justia's listing of the granted document): method claims directed to fabricating a semiconductor wafer — claim 1 = irradiating one or more surface locations of a silicon substrate with a plurality of temporally short laser pulses while exposing the locations to a substance to generate surface inclusions containing a constituent of the substance in a surface layer, then annealing the substrate at elevated temperature for a duration selected to enhance charge‑carrier density in that layer (dependents 2–11 recite electrons/holes, responsivity ranges of 1–200 A/W at 250–1100 nm, reverse bias 0.1–15 V, anneal 500–1100 K or 700–900 K, a few seconds–a few hours, 10–200 % carrier increase, ≥10× responsivity gain, and 0.1–100 A/W at 1050–3500 nm).

Important Research-Standing Caveat

The USPTO full-text databases are not directly queryable here; I retrieved bibliographic and citation data through the indexed Google Patents / Justia / DOE-OSTI records. The complete, itemized "U.S. Patent Documents – Referenced Cited" list for US 8,080,467 was only partially returned by the search tools. I confirmed the first entries but not the full list. Per your instruction not to fabricate identifiers, I am reporting below only what I could positively confirm, and I flag explicitly where data is incomplete rather than filling gaps with plausible-looking numbers.

What I positively confirmed as cited in the patent's "Referenced Cited" section:

• US 4,181,538 — Narayan et al. — January 1, 1980
• US 4,201,450 — Trapani — May 6, 1980
• A further entry whose number begins "4,277…" (rendered cut‑off in the source; I will not guess the suffix)

Additional citations certainly exist in the document but I could not retrieve their numbers verbatim. I recommend pulling the definitive list directly from the USPTO PatentCenter / Global Dossier "References Cited" tab or the front page of the granted PDF for US 8,080,467 to obtain the complete enumeration.

Confirmed Cited References — Analysis

1. US 4,181,538 — Narayan et al.

• Full citation: US 4,181,538, "Method for making defect‑free zone by laser‑annealing of doped silicon," Narayan et al., granted January 1, 1980; assignee United States of America (Oak Ridge National Laboratory / DOE). (OSTI ID 863479 confirms the number, title and assignee.)
• Disclosure: A method of improving electrical properties of silicon by irradiating a selected surface layer with high‑power laser pulses at a specified wavelength/energy/duration combination that melts the layer without degrading minority‑carrier diffusion length; expressly applied to n‑ and p‑type silicon "which is to be doped to form an electrical junction therein," and to removing doping‑induced defects from ion‑implanted or diffusion‑doped silicon.
• Potential § 102 relevance: This is the most structurally on‑point citation because it teaches laser irradiation of a doped silicon surface layer followed by/with annealing to restore or improve electrical (carrier) properties. It could be argued to bear on the laser‑irradiate‑then‑improve‑carrier‑properties concept underlying claim 1, and on the elevated‑temperature processing recited in claims 6–8. However, it does not disclose irradiating while exposing the surface to an electron‑donating substance (e.g., SF₆) to form sulfur inclusions, nor the responsivity ranges of claims 4, 5, 10, 11. It therefore appears to be § 102 background rather than a full anticipatory reference for any granted claim — consistent with the claims having issued over it.

2. US 4,201,450 — Trapani

• Full citation: US 4,201,450, Trapani, granted May 6, 1980.
• Disclosure / relevance: A 1980 optical/electro‑optic device patent cited as background art. It is not directed to sulfur‑hyperdoped laser‑microstructured silicon, so its § 102 exposure is limited to the most generic structural concepts (contact‑bearing optical/semiconductor devices) if any. It does not appear to anticipate any of the granted method claims 1–11.

(The remaining cited documents could not be enumerated from the available search results; they should be verified from the granted patent's front page before any § 102 conclusion is drawn about them.)

Highly Relevant Art in the Same Family / Cited in Sibling Patents

Although I could not confirm these appear on the 8,080,467 face, the following appear as cited references in closely related Harvard "black silicon" patents (e.g., US 10,371,579) and are the empirically most dangerous § 102/§ 103 art. I flag them as lead candidates for verification, not as confirmed citations of 8,080,467:

• Wu, C. et al., "Near‑unity below‑band gap absorption by microstructured silicon," Appl. Phys. Lett. 78, 1850–1852 (2001) — applicant‑authored, published before the 2002 priority filing; describes femtosecond‑laser microstructured silicon with strong sub‑bandgap absorption. Directly relevant to the microstructured‑silicon aspect of claim 1.
• "Back silicon, a new light absorber," Wu et al., APS Centennial Meeting, Mar. 23, 1999.
• Carey, J.E. et al., "Field Emission from Silicon Microstructures Formed by Femtosecond Laser Assisted Etching," CLEO 2001 (Baltimore), 555–556.
• Family members cited against/with it: US 7,057,256 (Carey III et al.), US 7,390,689 (Mazur et al.), US 7,504,702 (Mazur et al.), US 7,781,856 (Mazur et al.) — these are the parent/related patents, not anticipatory against 8,080,467 under § 102 (same inventive entity/family).

Bottom Line for a § 102 Assessment

1. The granted claims of US 8,080,467 are method claims whose novel element is the combination of (a) short‑pulse laser irradiation while exposing the silicon to an electron‑donating substance to create surface inclusions, and (b) annealing selected to enhance charge‑carrier density while preserving responsivity.
2. Of the references I could confirm, US 4,181,538 (Narayan et al.) is the closest on the laser‑irradiation/annealing‑of‑doped‑silicon axis and is the best § 102 candidate to argue against claim 1 — but it lacks the sulfur‑exposure feature and the specific responsivity/annealing‑range limitations of claims 4–11.
3. US 4,201,450 (Trapani) is generic optical‑device background and does not appear to anticipate any granted claim.
4. I could not retrieve the complete "Referenced Cited" list; any definitive anticipation opinion must first recover the full front‑page citation list (and any foreign/Non‑Patent Literature citations) from the USPTO PatentCenter record for US 8,080,467, which I am not able to enumerate in full from the sources reachable here.

Confidence note: The identification of the patent, its bibliographic data, and the two confirmed cited references (US 4,181,538; US 4,201,450) is high confidence. The completeness of the cited-reference list is low confidence due to the truncated search results; I have deliberately not reconstructed the missing entries to avoid fabricating identifiers.

I'll verify the key prior-art references before building the § 103 analysis.

Now let me verify the foundational microstructuring art and the PTAB reasoning, plus early sulfur-in-silicon annealing art.

Obviousness Analysis — U.S. Patent No. 8,080,467 B2 under 35 U.S.C. § 103

Building on: the claim summary, litigation/PTAB sections, and prior-art section already generated. I do not re-derive the bibliographic record, the IPR2017-00909 timeline, or the family chain; where those matter I cross-reference them and flag where I add information.

Scope/method note. I treated prior-art references as literally identified and did not auto-correct any number or citation. Where a reference's date is decisive (for § 102(b) status) I say so and flag unverified assumptions. I add several references beyond the two the prior-art section could positively confirm (US 4,181,538 and US 4,201,450), because a § 103 combination requires secondary art that teaches the annealing result, which neither of those supplies by itself.

1. The § 103 legal frame and the controlling claim

Pre-AIA § 103 governs (earliest priority 2001-05-25). The analysis is the Graham v. John Deere inquiry: scope/content of the prior art, differences between the claims and the art, PHOSITA level, and secondary considerations — with KSR Int'l v. Teleflex supplying the rationales (combining known elements; predictable use of prior-art elements; "a finite number of identified, predictable solutions"; design incentives; "obvious to try").

Claim 1 (independent, method). As summarized in the prior-art section, claim 1 requires only:

This is the pivotal observation for § 103. Claim 1 is not limited to a photodetector, a diode junction, an A/W responsivity, or a wavelength range. Its only recited effect of the anneal is increased carrier density in the surface layer. Every numeric window the specification touts (1–200 A/W; 250–1100 nm; 0.1–100 A/W at 1050–3500 nm; 0.5–5 at% S; conical microstructures; 700–900 K) lives in the dependent claims or the spec, not claim 1. That asymmetry drives the validity picture: claim 1 is the broadest and the most exposed; claims 4, 10 and 11 carry the real load.

2. The priority-date gateway (do this first — it decides whether the best art counts)

Hamamatsu argued in IPR2017-00909 that the '467 claims' effective date is the 2004-09-24 CIP filing, not 2001-05-25 — precisely because the Mazur-lab publications would then be unambiguous prior art. This is not a formality; it determines whether the closest art is § 102(b) art or only § 102(a)/(e) art subject to § 103(c) disqualification:

Consequence. Even if the Patent Owner wins the 2001-05-25 date, Her 1998, Carey/Sigmon 1989, Gibbons 1972 and Narayan 1980 remain unqualified § 102(b) prior art (>1 year before the 2002-05-24 filing), and Her 1998 alone discloses most of step (a). Only the Wu 2001 APL paper and the Wu thesis authorship issue are date-sensitive — and note that Wu 2001 lists Carey and Mazur as co-authors, i.e., the inventors, which raises the "by others" and § 103(c) common-ownership questions for that reference specifically. I flag rather than resolve this: the exact number of co-inventors and the common-ownership facts at the time of invention are not in the materials I have.

3. The reference set — element-by-element mapping

Caveat on the sulfur-silicon literature: the Forman/NBS paper is indexed with a 2011 online date, and Lynch is 2013 — i.e., on their face later than the 2001/2004 priority. I could not establish the original publication year of the Forman work from the sources I retrieved; the "550 °C" anneal content and the oxygen-donor comparison strongly suggest 1970s–80s NBS work, but that must be verified before using it as § 102(b) art. It is offered here as (i) evidence of the state of the art/PHOSITA knowledge about sulfur-in-silicon annealing if the original date checks out, and (ii) powerful later corroboration of what the art understood about anneal effects on sulfur centers.

4. The combinations and their motivation rationales

Combination A (the primary case): Her 1998 + Wu 2001 + Gibbons 1972

Where each limitation is met.

• Step (a): Her — 100-fs pulses at multiple locations, SF₆ ambient, conical microstructures (sulfur incorporated from SF₆). The claim's "temporally short" is fully met; the plurality of locations is met by Her's translated 500-pulse exposures. Wu supplies the sulfur/impurity-and-defect characterization and, critically, the photodetection purpose (enhanced below-bandgap photocurrent at 1.06/1.31 µm in microstructured APDs).
• Step (b): Gibbons — annealing introduced dopants so their "chemical effects … dominate," i.e., increasing the electrically active dopant (carrier) concentration. That is verbatim the recited function.

Why a PHOSITA would combine. This is a textbook KSR rational combination, not hindsight:

1. Known problem, known fix. A PHOSITA in 2001–2004 making a photodetector from Wu's material would immediately see Wu's own diagnosis: the below-bandgap response comes from "impurities and structural defects." Defects in a photodetector's active region mean recombination/G-R current and noise. The single most standard remedial step in silicon processing for a damaged/implanted/amorphized layer is a thermal anneal (Gibbons).
2. Same field, same art, overlapping authors. Both the microstructuring art and the anneal art are silicon optoelectronic processing; Her/Wu and Gibbons are all in the same technology of controlling a doped, damaged silicon surface layer.
3. Express teaching, not silence. Gibbons does not merely imply annealing; it states the rule — anneal if you want the dopant's chemical (electrical) effect to control the material rather than residual damage. That is an articulated reason with a rational underpinning, which is exactly what the Board found lacking in Hamamatsu's petition.
4. Actually making a device. Wu's APD results (photocurrent at 1.06/1.31 µm) create the design incentive to convert a laboratory absorption curiosity into a junction-coupled detector; the natural next steps are contact formation and a junction-quality anneal — the point at which Carey/Sigmon GILD (Combination B) reinforces the "laser + dopant gas → junction" teaching.

Combination B: Carey/Sigmon GILD (1989) + Her 1998/Wu 2001 [+ Gibbons]

Where: GILD teaches the genus "pulsed-laser irradiation of silicon in a dopant-containing gas to incorporate dopant into the surface." Her/Wu teach the species where the dopant gas is SF₆ and the result is a microstructured, below-bandgap-absorbing layer. GILD also teaches the melt-and-regrow mechanism that inherently activates dopant.

Why combine: In re the substitution-of-known-elements rationale — swapping one dopant gas (B₂H₆/AsH₃) for another known dopant gas (SF₆) in a known laser-doping process is the kind of "predictable variation" KSR endorses, especially where the art already used SF₆ for fs-laser microstructuring (Her). And GILD's melt/regrowth is the enabling teaching for why a laser-doped surface layer ends up electrically active. The Board itself entertained this pairing only as to claim 3 (Grounds 3–4), so it is not the ground that was denied on the merits — a point of some significance for anyone contemplating a fresh proceeding.

Combination C: Narayan (US 4,181,538) + Her 1998/Wu 2001

Narayan teaches laser annealing of doped silicon specifically to improve electrical properties without degrading minority-carrier diffusion length — i.e., it pairs the laser and the anneal-to-improve-electrical-quality ideas in one document, and it expressly contemplates forming an "electrical junction therein." Combine with Her/Wu (which supply the dopant-bearing gas and the microstructured absorber) and you get claim 1. Narayan is the most structurally on-point patent citation — exactly the opposite of what the Board considered, since Hamamatsu's grounds rested on Gibbons+NPL and never put Narayan's laser-anneal-of-doped-silicon teaching at the center.

Combination D: Forman et al. (sulfur-center anneal) + Her/Wu

If the original NBS publication date establishes it as prior art, this is the most dangerous reference for the Patent Owner, because it is sulfur-specific: it establishes that the electrical and optical properties of sulfur centers in silicon, and the relative densities of sulfur donor states, are governed by annealing. That supplies the missing link the Board criticized Hamamatsu for omitting — an articulated reason to anneal a sulfur-doped silicon layer (not generically an implanted layer) in order to change its carrier/electrical character. It maps directly onto the specification's own theory of the invention (§ "sulfur … before annealing … donor electrons do not substantially contribute to conduction … annealing causes atomic bond rearrangements … to free up donor electrons").

Combination D's internal irony is the strongest § 103 argument against the patent: the '467 specification states that the sulfur is already present after laser irradiation and that annealing merely releases the donor electrons. Framed that way, the invention is the activation of a known dopant in a known matrix by a known technique — the paradigm of § 103, tempered only by whether the optical outcome was predictable (see § 5).

5. The obviousness headwind, head-on: teaching away and unexpected results

This is where the prior-art section's caution and the PTAB section's detailed findings must be reconciled — and they point the same direction as the art itself.

5.1 The established "teaches away" evidence

• IPR2017-00909 (Paper 9, 2019-09-04) records the Board's reasoning: the Wu Thesis "does not posit the use of annealing to improve the performance of a photovoltaic device, or suggest any positive effect of annealing on dopant activation or on the electrical properties of spiked silicon," and its own annealing protocol "prove[d] deleterious to the functionality of the silicon device, particularly to its infrared wavelength absorptance capabilities."
• Independent, post-dating confirmation from the modern literature I retrieved: thermal annealing of sulfur-hyperdoped monocrystalline silicon (from ion implantation or fs-laser irradiation) "usually decreases" sub-bandgap infrared absorption, via deactivation — S atoms migrating from substitutional (active) to interstitial/precipitate (inactive) sites (Materials Science in Semiconductor Processing, 2022). The Harvard-area thesis work likewise concludes that attempts "to thermally anneal the laser-implanted layer were misguided, as the sulfur dopants will simply precipitate out in equilibrium configurations" (pub_648.pdf).
• So the art did not merely fail to suggest the anneal — it affirmatively taught that the anneal would destroy the very below-bandgap absorption the '467 claims exploit. That is classic In re Gurley/DePuy teaching-away (a critical limitation — preservation of below-bandgap responsivity — is disclosed as inoperable by the prior art).

5.2 But the teaching-away is partially blunted

The Board's "deleterious" finding is about IR absorptance. Claim 1, however, requires only enhanced carrier density — and the same modern literature reports that annealing first increases carrier concentration by ~60% before it later collapses (Harvard Dash thesis: "n_s first increases by about 60% and then decreases to about 10% of its initial value"). A ~60% increase sits squarely inside claim 9's "10%–200%" window and inside claim 1's bare "enhance the charge-carrier density" limitation.

This produces a legal asymmetry worth stating plainly:

Bottom line on the headwind: the teaching-away argument defeats any attempt to invalidate the photodetector-performance claims (10, 11, and to a lesser degree 4) on the Her/Wu + Gibbons/GILD/Narayan axis. It does not rescue claim 1, because claim 1's only recited consequence of annealing — greater carrier density — is what the very references relied on by the Patent Owner (Gibbons; and even the "deleterious" literature, which shows an initial ~60% rise) say annealing does.

6. Secondary considerations (Graham factor 4)

Caution on nexus. All the favorable secondary evidence attaches to the performance of the annealed material/device (claims 4, 10, 11). Harvard/SiOnyx's problem is that the commercial story is about imaging sensors (the later Sionyx patents cited in the "Cited By" table of US 7,847,253), which is a different claimed invention from claim 1's process. A defendant can therefore concede the unexpected IR results while still arguing claim 1 is obvious — those results are recited in claims 10–11, not claim 1.

7. Assessment summary

Direct answer to the question posed. The claims of US 8,080,467 that recite only the process and its carrier-density effect (claim 1, and the anneal/parameter dependents 5–9) are, on this record, vulnerable to § 103 as a combination of (i) Her 1998 / Wu 2001 (laser irradiation in SF₆ producing a sulfur-incorporated, microstructured silicon surface), and (ii) Gibbons 1972 and/or GILD 1989 and/or Narayan '538 / Forman (annealing to activate the introduced dopant and raise carrier density), with the motivation supplied expressly by Gibbons ("the crystal must be carefully annealed if the chemical effects of the implanted ions are to dominate") and by Wu's own defect-based explanation of the below-bandgap response (defect repair + dopant activation are the standard remedies). The claims that recite preserved below-bandgap responsivity — principally claims 10 and 11, and arguably 4 — are materially stronger, because the very art one would combine expressly taught away from annealing sulfur-hyperdoped silicon for infrared purposes, and post-2004 literature confirms annealing ordinarily deactivates sulfur and suppresses sub-bandgap absorption.

8. What I could not verify (stated rather than assumed)

1. Verbatim granted claim text. As flagged in the prior sections, the supplied full text omits the claims; I relied on the Justia excerpt. If the grant contains an apparatus/photodetector independent claim not reflected in that excerpt, the § 103 picture for that claim is different (and stronger for the Patent Owner). Pull the PDF from PatentCenter.
2. Original publication year of the Forman/NBS sulfur-center paper. Indexed with a 2011 online date; content implies 1970s–80s NBS work. Not confirmed as pre-2001/2004 art. Do not assert § 102(b) status without checking.
3. The complete "Referenced Cited" list on the '467 face (the prior-art section could confirm only US 4,181,538 and US 4,201,450, with a third cut off at "4,277…"). I did not fabricate the remainder.
4. Whether the PTAB's full institution-denial and rehearing-denial texts are quoted accurately here. My quote of the "deleterious … infrared wavelength absorptance" language and the "no positive effect of annealing on dopant activation" language is taken from the PTAB section of this analysis, which cites IPR2017-00909 Paper 9 (2019-09-04). I did not independently re-fetch Papers 7 and 9 in this step; verify against PTAB E2E if the quotes will appear in a filing.
5. Whether claim 11's "0.1–100 A/W at 1050–3500 nm" and claim 4's ranges are as summarized (from the Justia excerpt) — confirm against the grant.

Key sources for this analysis: Her 1998 (doi:10.1063/1.122241); Wu 2001 (doi:10.1063/1.1358846); Gibbons 1972 (doi:10.1109/PROC.1972.8854); Carey & Sigmon GILD 1989 (doi:10.1016/0169-4332(89)90234-1); Forman et al., MRS Proc.; Lynch et al. 2013; annealing deactivation of S-hyperdoped Si (2022); Harvard thesis on deactivation kinetics.