US 10345246

I'll verify the current status of this patent against live sources before summarizing.

Verification and scope of search

I checked live sources for litigation and appellate activity on US 10,345,246 before summarizing.

• USPTO / Google Patents record: found and consistent with the full text supplied — https://patents.google.com/patent/[US10345246B2](/patent/US10345246B2)/en
• CAFC 2026 dockets: I found no Court of Appeals for the Federal Circuit docket, appeal, or argued case involving this patent number in my searches. A targeted query for a 2026 Federal Circuit appeal returned no results.
• IPR / PTO trial proceedings: no IPR, PGR, or reexamination record surfaced for this patent.
• District court litigation: no infringement action naming US 10,345,246 surfaced.

Uncertainty note: absence of search hits is not proof of absence. My searches were general web searches, not a direct Docket Navigator / PACER / CAFC case-management-system query, so I cannot state with high confidence that no 2026 appellate or district-court activity exists. Treat "no litigation found" as a search-result finding, not a legal conclusion.

I interpreted the number literally as 10,345,246 (US 10,345,246 B2) and did not substitute or auto-correct any similar number.

Bibliographic data

Classification: G01N 21/88 (first), G01N 21/49, G01N 21/95, G01N 21/47; CPC G01N 21/9501, G01N 21/8806, G01N 2021/4735, G01N 2021/8822, G01N 2201/06113. Notably, the CPC slot G01N2021/8822 — "Dark field detection" and G01N2201/06113 — "Coherent sources; lasers" align directly with the claimed subject matter.

International family (7 jurisdictions): JP 7134096 B2, KR 102357638 B1, CN 109196336 B, SG 11201810682P A, TW I738788 B, WO 2017/210281 A1 (PCT/US2017/035187). The WO record shows the PCT as Ceased/not_active, while the US, JP, KR, CN, and TW members are recorded as active.

Abstract (as granted)

Provided is a method, system, and apparatus for inspecting a substrate. The method comprises illuminating the substrate with a singular laser beam, the singular laser beam forming an illuminated spot on the substrate and a bright fringe at a surface of the substrate, the bright fringe extending over at least a portion of the illuminated spot, and detecting, by an optical detection system, scattered light from nano-defects present on the substrate within the illuminated spot.

Plain-language overview of the independent claims

Claim 1 — Method

Shine a laser beam that has a spatial phase singularity onto the wafer. The beam produces (a) an illuminated spot and (b) a standing wave above the wafer that contains at least one bright fringe and at least one dark fringe, with the bright fringe overlapping at least part of the spot. Then detect, using a dark-field detection system, light scattered by nano-defects located inside the illuminated spot.

Plainly: the invention's core trick is that when a collimated beam reflects off a wafer at oblique incidence, the incident and reflected wavefronts interfere into a standing wave. With ordinary (Gaussian) light the physics locks a dark node at the wafer surface, so a 5–20 nm particle sitting right on the surface is barely illuminated and scatters almost nothing. By imposing a spatial phase singularity on the beam — the description's worked example is a π phase jump across the beam centerline — the standing-wave pattern flips, so a bright fringe sits at the surface. Surface nano-defects then see substantially more light and scatter more light, improving signal-to-noise.

Claim 15 — System

A system comprising: a substrate stage that receives the wafer; a laser light source; illumination optics that direct the source light onto the substrate and are configured to form a laser beam having a spatial phase singularity so as to form an illuminated spot and a standing wave with bright/dark fringes on the substrate; and a dark-field optical detection system that detects illuminated nano-defects by detecting their scattered light.

Plainly: the hardware/equipment counterpart to claim 1 — stage + laser + beam-shaping optics producing the singularity beam + dark-field collector.

Claim 20 — Apparatus

An illumination system that forms a laser beam having a spatial phase singularity from a laser light source and directs it to the substrate (the beam forming an illuminated spot and a standing wave with at least one bright fringe and at least one dark fringe on the substrate), plus a dark-field optical detection system that detects illuminated nano-defects by detecting scattered light from them.

Plainly: drafted as an apparatus-only framing (illumination subsystem + dark-field detection subsystem), which overlaps substantially in substance with claim 15 but omits the recitation of the substrate stage as an element of the claimed apparatus.

Support in the specification for the independent claims

• Standing-wave physics: fringe spacing h = λ/2 cos(θ); Gaussian-illumination surface amplitude I(x,θ) = I_t sin((2π/λ)x)cosθ with I_t = 4I_i (eq. 3); singular-beam surface amplitude I(x,θ) = I_t cos((2π/λ)x)cosθ (eq. 4).
• The numerical payoff: intensity ratio I_singular/I_Gaussian = cot((2π/λ)x), so the singular beam wins for x < λ/8 and loses for x > λ/8. Worked example: a 17 nm particle illuminated by a 355 nm collimated beam receives ~3× the intensity from the singular beam versus a Gaussian beam.
• Detection target: the specification states the system "can detect nodes ranging from 20 nm to 5 nm."
• Beam generation: a flat-top beam shaping stage followed by a phase mask with a π phase jump at the centerline; alternately, a phase plate of step height d = λ/(2(n−1)) inserted into a Gaussian beam; multiple phase jumps (FIG. 9) are disclosed as a further-sensitivity variant via time-integrated scattered signal at the detector.

Claim-drafting observations (flagged, not legal conclusions)

1. Terminology shift between specification and claims. The specification defines the operative beam as a "singular beam," described as "a combination of Gauss-Laguerre beams or modified forms of Gauss-Laguerre beams," and consistently describes it operationally as at least two beam portions separated by a phase difference (π radians). The granted independent claims instead recite "a laser beam having a spatial phase singularity." A π-step across a centerline is a phase dislocation; a canonical Gauss-Laguerre/vortex singularity is an azimuthal phase ramp with a dark core. Whether the claim term reads on the disclosed π-step embodiment is a potential claim-construction question, not something I can resolve here.

2. Antecedent basis. Claim 6 recites "an angle of incidence of the singular laser beam" although claim 1 introduced the beam as "a laser beam having a spatial phase singularity." This is an apparent antecedent-basis inconsistency on the face of the granted text. A certificate of correction was recorded 2020-04-21, but I could not retrieve its contents, so I cannot say whether this was corrected. Do not assume the text I have reflects post-correction claim wording.

3. Claim 15 typographical issues. Claim 15 opens "A system for inspection a substrate" (rather than "inspecting"), and recites "directing light from the laser light source on the substrate." Claim 17 omits a comma after "a bandpass filter." These read as clerical rather than substantive, but again — an unretrieved certificate of correction means I cannot confirm the current official text.

4. Claim 1 is a method with a "dark field" detection limitation, and dependent claim 8 narrows detection to "a direction substantially perpendicular to the substrate" — i.e., a normal-incidence collection path. Dependence structure: claims 2–14 depend on 1; claims 16–19 depend variously on 15 and 17.

Prior art of record (selected, as cited)

US patents/publications: US 6,288,780 B1 and US 7,554,655 B2 (KLA-Tencor, high-throughput brightfield/darkfield wafer inspection); US 9,194,811 B1 (KLA-Tencor, improving defect detection sensitivity); US 7,705,331 B1 (KLA-Tencor, illumination for specimen processing); US 8,912,495 B2 (KLA-Tencor, multi-spectral defect inspection for 3D wafers); US 2015/0226676 A1 (KLA-Tencor, combined brightfield/darkfield/photothermal inspection); US 9,753,379 B2 (ASML, inspection apparatus and methods); US 4,893,932 A (Particle Measuring Systems, surface analysis); US 5,781,294 A (Hitachi, photoacoustic surface/subsurface detection); US 2007/0070336 A1 (Maeda, defect inspection of patterns).

Non-patent literature:

• A. S. van de Nes et al., "Rigorous Analysis of Spheres in Gauss-Laguerre Beams," Optics Express, Oct. 1, 2007, vol. 15, no. 20 (15 pages) — the Gauss-Laguerre scattering reference most directly on point for the "singular beam" concept.
• Evyatar Hemo et al., "Scattering of Singular Beams by Subwavelength Objects," Applied Optics, Jan. 1, 2011, vol. 50, no. 1, pp. 33–42.
• International Search Report and Written Opinion dated Aug. 11, 2017 in PCT/US2017/035187.

Forward citations trend (13 examiner/third-party + related): concentrated in metasurface/metalens optics (Metalenz, Harvard, Columbia) and particle-measurement instrumentation (Particle Measuring Systems), rather than in wafer-inspection art — suggesting limited subsequent citation by direct semiconductor-inspection competitors on the face of the record.

Bottom line

US 10,345,246 is a Tokyo Electron–owned, still-active patent (filed 2017-06-01, issued 2019-07-09, priority 2016-06-02) covering the use of a laser beam bearing a spatial phase singularity to place a bright standing-wave fringe at a wafer surface so that sub-20 nm dark-field nano-defects scatter measurably more light. Its three independent claims are a method (claim 1), a system (claim 15), and an apparatus (claim 20). I found no recorded CAFC, district court, or PTAB activity, but my search was not a direct docket-database query, and I could not retrieve the 2020 certificate of correction — both caveats should be resolved against authoritative records before relying on the claim text or the litigation-free status.

I'll search for litigation involving US patent 10345246 across patent litigation databases and court records.

Let me search more targeted litigation databases for this specific patent.

Let me try litigation-specific databases and additional targeted searches.

Findings: Litigation Involving U.S. Patent No. 10,345,246

No litigation involving U.S. Patent No. 10,345,246 was found.

I searched Google Patents, PubChem patent records, USPTO.report, Justia Patents, Unified Patents-related results, and general litigation/docket coverage for the patent number, its title, and its assignee (Tokyo Electron Limited). None of the searched sources identified any federal district court case, ITC investigation, PTAB proceeding, or Federal Circuit appeal in which U.S. Patent No. 10,345,246 was asserted, challenged, or otherwise at issue.

Important caveat on search limitations

My tool access returned mostly patent-document aggregators and prosecution materials rather than a comprehensive litigation docket. I was not able to complete a direct query of PACER, the Unified Patents litigation caselist (https://portal.unifiedpatents.com/litigation/caselist), or Docket Navigator/Lex Machina before exhausting my search steps. A negative result here is therefore not a guarantee that no litigation exists — it means no litigation surfaced in the sources I could reach. To be fully certain, a direct PACER/Unified Patents/Docket Navigator query on patent number 10,345,246 would be needed.

What the searches did surface (contextual only — NOT litigation of this patent)

• Patent bibliographic data: US 10,345,246 B2, "Dark field wafer nano-defect inspection system with a singular beam"; inventors Xinkang Tian, Ching-Ling Meng, Yan Sun; assignee Tokyo Electron Limited; priority date 2016-06-02; filed 2017-06-01; granted 2019-07-09; application no. 15/611,290.
• Prosecution/post-grant events (from the patent's legal-events record): a Certificate of Correction (2020-04-21) and a 4th-year maintenance fee payment (2022-12-28, large entity). These are prosecution/maintenance events, not litigation.
• Unrelated litigation that appeared in results but does not involve this patent: Tegal Corp. v. Tokyo Electron America, Inc. (E.D. Va., No. 3:98CV318, re: the '223 patent — a 1990s etching-technology case, captioned in 257 F.3d) and various Applied Materials/Semitool/Bosch cases. None concern US 10,345,246.
• The patent's "Cited By" and foreign-family listings (e.g., JP7134096B2, KR102357638B1, CN109196336B, TWI738788B, WO2017210281A1) are patent-family/citation records, not litigation.

Bottom line

Based on the sources reachable in this search: no known litigation is associated with U.S. Patent No. 10,345,246. If you require a definitive litigation clearance, I recommend a direct PACER docket search and a Unified Patents / Docket Navigator query on the exact number 10,345,246 (not 10,345,246-family members or similar numbers).

I'll verify the structured block's "no proceedings" default against live sources before writing.

Let me run a couple more targeted checks on PTAB docket aggregators before concluding.

PTAB Proceedings Report — U.S. Patent No. 10,345,246

Proceedings overview

There are zero (0) AIA trial proceedings on file against U.S. Patent No. 10,345,246. The structured USPTO Open Data Portal "PTAB proceedings on file" block returns no IPR, PGR, or CBM for this patent, and my independent searches (Google Patents litigation/PTAB tabs, general PTAB docket searches, and petitioner-side queries naming Tokyo Electron) surfaced no proceeding number, no petition, and no institution decision. I found no proceeding to report, and I am not going to manufacture one.

Bottom-line defensive posture: untested, not hardened. This is important framing, because the two available narratives in the prompt both misfire here. The patent has not "survived two IPRs" — it has never been to the Board at all. And no claims have been canceled, so there is no dead-claim shortcut for a defendant. All 20 claims stand exactly as granted (subject to a 2020-04-21 certificate of correction whose substance I could not verify from the sources available to me). A defendant facing assertion today is looking at a clean-slate validity fight, not an estoppel-bound mop-up.

One further correction to the prompt's framing: the "troll has no case" scenario presupposes a non-practicing entity. The assignee here is Tokyo Electron Limited, a large operating semiconductor-equipment manufacturer. The absence of IPRs against a TEL patent is a plausible signal of a well-defended, unasserted portfolio rather than of a patent nobody cared about — but it is an inference, not evidence, and I flag it as such.

Per-proceeding detail

None. No AIA trial proceeding has been instituted, filed, or terminated against this patent on the record available to me.

For completeness, the closest things in the public record that might be mistaken for PTAB activity — and which are not PTAB activity — are:

• Foreign family members (prosecution, not trials): JP7134096B2, KR102357638B1, CN109196336B, SG11201810682PA, TWI738788B, WO2017210281A1.
• Forward citations by later third parties (Google Patents "Cited By" / "Families Citing this family"): Metalenz, Particle Measuring Systems, Harvard, Intel, 深圳中科飞测, (주)넥스틴, and others cite this patent as prior art or in later filings. Citation ≠ challenge. Two of these — KR102946366B1 ("Dark-field inspection device with real time variable function," NexTIN) and CN113125456B (中科飞测) — are in the same dark-field inspection space and are worth monitoring as competitor art, not as proceedings.

Strategic summary

Claim status: every claim is UNTESTED. Claims 1–20 of 10,345,246 have never been construed by the PTAB, never been the subject of an institution decision, and never been canceled. Independent claims are 1 (method), 15 (system), and 20 (apparatus); each carries dependents addressing the same concepts — a spatial phase singularity / at-least-two-beams-separated-by-a-phase-difference (§ claims 2–4), π-radian phase difference (claim 3), phase mask or phase retarder (claim 4), s- or p-polarization (claim 5), AOI 1°–90° (claim 6), EUV/DUV/UV/visible wavelength (claim 7), perpendicular detection (claim 8), and the objective-aperture-relay-bandpass-detector-array stack with PMT/TDI-CCD, chromatic-aberration correction, autofocus, and image computer (claims 9–13). Note the prosecution-era language "singular laser beam" in the specification versus the granted claim language "laser beam having a spatial phase singularity" — that gap between spec and claim is the kind of thing that drives claim-construction fights, but no tribunal has yet picked a side.

Estoppel landscape: there is none to worry about — yet. Because no IPR or PGR has been filed, 35 U.S.C. § 315(e)(2) estoppel has not attached against anyone, and there are no privies of prior petitioners to worry about. This cuts both ways for a defendant:

• In your favor: you are not boxed in by someone else's clumsy petition. You can run your best § 102/§ 103 grounds de novo, in the forum of your choosing, with your own expert and your own claim constructions.
• Against you: you get one bite, and § 315(e)(2) will attach to your petition the moment an FWD issues. If you file an IPR on weak art and lose, you have burned your best grounds and handed the patent owner a validated patent to wave at the jury.

Statutory clock facts that matter. The patent issued 2019-07-09. The PGR window closed 2020-04-09 (§ 321(c), nine months post-grant). Only IPR remains available as an AIA vehicle. Critically, § 311(b) limits IPR to "prior art consisting of patents or printed publications." For an optical inspection system of this type, the most damaging art is often a prior public use, sale, or on-sale bar (§ 102(a)(1)) — a shipped inspection tool, a conference demo, a product brochure that is a printed publication only if you can prove public accessibility. Public-use and on-sale art cannot be raised in an IPR at all. If your best invalidity theory is a prior machine rather than a prior document, an IPR is the wrong vehicle and you should be thinking about § 282 district-court invalidity, an early SJ posture, or a strong § 112 indefiniteness/enablement attack on the "spatial phase singularity" and "bright fringe … extending over at least a portion of the illuminated spot" limitations.

Pattern signals. No repeat-petitioner pattern exists because there are no petitioners. No defensive aggregator (Unified Patents, RPX, Open Invention Network) appears anywhere in the record for this patent. The patent owner has not pursued PTAB appeals, for the obvious reason that it has never been in a PTAB trial. The portfolio has a strikingly international footprint for a US-issued patent — active counterparts in JP, KR, CN, SG, TW, and a PCT — which is consistent with a deliberate, well-funded filing strategy around a commercially valuable inspection technology rather than a patent monetization play.

Recommended next steps

1. Do not build a defense on a PTAB record that does not exist. Any argument of the form "the PTAB already invalidated these claims" is unsupported and should not appear in a client memo or a stay motion. If you have seen such a claim in an internal document, it is an error.

2. Establish the § 315(b) clock immediately. IPR is barred if the petition is filed more than one year after the petitioner is served with a complaint alleging infringement of this patent. Confirm service dates for your client and for any privies (parent/subsidiary, real party in interest). If no complaint has been served, there is no bar and no deadline — which is the best possible position from which to prepare a petition carefully rather than hastily.

3. Sanity-check the patent's family before investing. Verify against USPTO Patent Center whether 10,345,246 has continuations, divisionals, or provisionals in the same family beyond provisional 62/344,575. A narrow IPR win on this patent is worth little if a continuation with overlapping claims exists, or conversely, if you can invalidate claim 1 with art that also kills the family, the investment multiplies. Note the 2020-04-21 certificate of correction — obtain the corrected text before charting claims, since a correction can move claim scope.

4. Decide forum by art type, not by reflex. If your art is patents and printed publications, an IPR is efficient and the PTAB's Phillips-style construction (§ 42.100(b)) now tracks district court. If your art is a prior tool, a public demo, or a sale, skip the PTAB entirely and run § 102(a)(1) in the district court, backed by corroborating documentary evidence.

5. Monitor for the first filing. Because this patent is untested, the first IPR — whoever files it — will function as free claim-construction and validity discovery for every later defendant. Set a docket alert.

Sources and verification links

• Patent record (Google Patents, incl. litigation/PTAB tabs): https://patents.google.com/patent/[US10345246B2](/patent/US10345246B2)/en
• USPTO PTAB E2E / PTAB Center case search: https://ptacts.uspto.gov/ptacts/
• USPTO Patent Center (family, certificate of correction, assignment): https://patentcenter.uspto.gov/
• CourtListener, for any district-court or Federal Circuit activity: https://www.courtlistener.com/

Verification caveat, stated plainly: I searched and found nothing. I did not have direct access to the USPTO ODP API, to PTAB E2E behind authentication, or to a full district-court docket sweep for this patent. It is possible a very recently filed petition is not yet indexed in the sources I can reach. Before relying on "no PTAB activity" for a stay motion or an IPR strategy memo, confirm directly against PTAB E2E and the Patent Center litigation tab on the day you file.

I'll verify the assignment record against the sources before writing it up.

Inventors

Pattern note — no distressed-inventor signal. The assignment-inventory data shows the opposite of the fire-sale tell: Tian and Meng continue filing TEL applications well past this patent, e.g. US 10,978,278 (2021-04-13), US 11,961,721 (2024-04-16), US 12,261,030 (2025-03-25), all assigned to Tokyo Electron Limited. Continuity of the same inventor team on the same corporate docket ~8 years after this filing is evidence of a live, funded internal program, not an abandoned portfolio. I found no evidence of any inventor departing TEL, and I state plainly that I did not verify employment agreements or departure dates from any primary HR source — no such record is public.

One bibliographic discrepancy worth flagging rather than smoothing over: the PCT publication WO2017210281A1 (US/2017/035187) is indexed by at least one aggregator (patentguru) as naming only Meng and Tian, while the granted US patent names three inventors including Sun. That is an indexing artifact I could not resolve; the authoritative US claim of inventorship is the three-inventor set.

Original assignee

Tokyo Electron Limited (Tokyo, JP) — the entity on the face of US 10,345,246 and the applicant of record on the parent PCT.

• Primary line of business: semiconductor and flat-panel-display production equipment (coaters/developers, etch, deposition, cleaning, wafer probers, and process-monitoring/inspection sensors). The patent's own disclosure (dark-field wafer nano-defect inspection, 5–20 nm node sensitivity, PMT/TDI-CCD detection) reads directly on TEL's in-chamber and stand-alone metrology product lines, and flows from the same Silicon Valley team that produced TEL's "normal-incidence in-situ process monitor sensor" family.
• Product embodying the claims: TEL is unambiguously an operating company that ships semiconductor process and metrology equipment. I did not find a published product datasheet that expressly claims the singular-beam standing-wave illumination of claim 1; that specific mapping is unverified. Say it plainly: this is an operating-company R&D portfolio patent, with product embodiment highly plausible but not documented here.
• Current status: operating, publicly listed on the Tokyo Stock Exchange (TSE: 8035). No Chapter 7/11, no receivership, no dissolution. No change of name or merger affecting the assignee appears in the chain. (The abandoned 2013–2014 Tokyo Electron–Applied Materials combination never closed and produced no assignment of this portfolio.)

Assignment timeline

The USPTO assignment record for this patent contains exactly one recorded assignment — the original inventor-to-company transfer. There are no post-issuance transfers of any kind. I verified this against the Google Patents legal-events record for US10345246B2; I did not successfully retrieve a live Assignment Center result page (see caveat below), so treat the single-link finding as high-confidence but not Assignment-Center-confirmed.

• 2019-02-12 (executed) / recorded 2019-02-25 — Reel 048430/0552
  • Conveyance: Assignment (Assignment of Assignors' Interest)
  • Assignor: Xinkang Tian; Ching-Ling Meng; Yan Sun — each signing individually as inventor
  • Assignee: Tokyo Electron Limited, Japan
  • Correspondent: Not available in the sources I could access. The Google Patents legal-events entry for reel 048430/0552 publishes the owner name and reel/frame but not the recording correspondent. I did not fabricate one, and I did not obtain the Assignment Center abstract, which is where the filing attorney/agent of record would appear. Treat the correspondent field for this patent as unretrieved, not as "none."
  • Context: Confirmatory / chain-of-title perfection, not a commercial transfer. The execution date (2019-02-12) lands ~2.5 years after the 2017-06-01 filing and days after the notice of allowance was mailed (2019-02-21 STPP event), i.e. a signature-ready formality executed to clean up title before the 2019-07-09 grant — the normal pattern for a foreign corporate applicant whose US-filed application was prosecuted company-first.

Adjacent legal events that are NOT assignments (do not misread these as ownership changes):

• 2019-02-21 — Notice of allowance mailed (STPP).
• 2019-07-09 — Patent granted (STCF).
• 2020-04-21 — Certificate of correction (CC). A correction is not a conveyance.
• 2022-12-28 — Maintenance fee, 4th year, large entity. Payment by TEL confirms the assignee was still the fee-paying owner as of 2022-12-28.

Family-level note: the same invention is recorded in JP7134096B2, KR102357638B1, CN109196336B, TWI738788B and SG11201810682PA, all still shown under Tokyo Electron. Those jurisdictions each carry their own recordal; I did not fetch them, and a non-US transfer there would not change the US chain.

Correspondent-recurrence analysis is not performable here. Signal 3 requires at least two recorded links to detect recurrence. This chain has one. A single appearance by any firm is expressly not a finding under the brief, so no correspondent call can be made in either direction.

Timeline diagram

timeline
    title Ownership of US 10345246
    2016 : Provisional filed by Tokyo Electron
    2017 : Non-provisional filed Jun 1
         : PCT published Dec 7
    2019 : Inventors assign to Tokyo Electron
         : Patent issued Jul 9
    2020 : Certificate of correction
    2022 : 4th year maintenance fee paid

NPE / troll-pattern signals

1. Shell-entity transfer — not present. The sole recorded conveyance (reel 048430/0552, recorded 2019-02-25) moves title into the operating parent, Tokyo Electron Limited, and never out of it. No IP-holding LLC, no "Holdings/Ventures/Licensing" suffix, no registered-agent service address anywhere in the chain. There is no downstream assignee to test.

2. Known asserter in the chain — not present. Assignee is Tokyo Electron Limited; no Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Conversant/Mosaid, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, or Spangenberg-linked entity appears at any point on reel 048430/0552 or in the legal-events record.

3. Repeat correspondent across the chain — not present / not determinable. With one recorded link, recurrence is mathematically impossible, and the correspondent of record was not retrievable from the sources available to me for reel 048430/0552. Recorded as unclear due to missing data, explicitly not as a clean negative.

4. Cascading transfers — not present. Zero assignments after the 2019-02-25 recordal. No chained LLC hops, no shared correspondent addresses, no common-principal pattern — the sequence stops at one.

5. Pre-litigation transfer — not present. The 2019-02-12 execution predates grant (2019-07-09) and is a title-perfection step; it is not within 6 months before any infringement suit, because I found no infringement suit naming this patent and no TEL assertion campaign against competitors on this family.

6. Bankruptcy fire-sale — not present. TEL is a solvent, TSE-listed operating company; no Chapter 7/11 proceeding is associated with this assignee or this patent, and the 2022-12-28 maintenance-fee payment (large entity) is inconsistent with abandonment economics.

7. Privateering — not present. No operating company → NPE transfer exists here; TEL retained title and pays its own maintenance fees. There is no evidence of a proxy asserter acting on TEL's behalf.

8. Defensive aggregator — not present. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN. So there is no "neutralization" inverse signal either — this patent is simply still held by its corporate owner.

Net: all eight signals resolve to negative or (one) undeterminable-for-lack-of-data. Not a single affirmative NPE indicator.

Verdict

Insufficient data — applying the rubric literally: this patent has only the original assignment (reel 048430/0552, executed 2019-02-12, recorded 2019-02-25, inventors → Tokyo Electron Limited), so the record is exactly the case the rubric assigns to this category.

Substantively, every datapoint points the same way: an operating-company-held, never-transferred portfolio patent. The chain terminates at Tokyo Electron Limited — a TSE-listed equipment maker that paid the 4th-year maintenance fee on 2022-12-28 — and the same three inventors were still filing TEL applications as late as 2025. There is no NPE, no troll, no assertion and no shell entity anywhere in this record; the only "unusual" feature is the late execution date of the confirmatory assignment four days after the notice of allowance, which is administrative, not commercial.

Verify the single record and check for any 2019–2026 entries I could not retrieve by searching this patent number at https://assignmentcenter.uspto.gov/ (and the legacy index at https://assignment.uspto.gov/patent/index.html). If that search surfaces a second reel/frame, the correspondent-recurrence and cascading-transfer signals (3 and 4) would need to be re-run — they are the two that a single additional link could flip.

I'll research this patent and its cited prior art. Let me start with searches on the patent and key references.

Let me research the most relevant patent references in the citation list.

Prior-Art Analysis — US 10,345,246 B2

Patent: US 10,345,246 B2 — "Dark field wafer nano-defect inspection system with a singular beam"
Assignee: Tokyo Electron Ltd.
Inventors: Xinkang Tian, Ching-Ling Meng, Yan Sun
Priority date: 2016-06-02 (US provisional 62/344,575) · Filed: 2017-06-01 · Granted: 2019-07-09

Method/scope note: I retrieved the patent's own citation records (the authoritative "Citations," "Family Cites Families," and "Non-Patent Citations" lists) and verified several references (US 4,893,932; US 6,288,780; and the two NPL articles) via live search. The remaining entries below draw on the citation metadata in the patent text plus my knowledge of the references. Where I am not fully confident of a reference's technical content, I flag it explicitly rather than assert it.

1. The claims that prior art must meet

Everything hinges on claim 1, which requires all of:

1. illuminating the substrate with a laser beam having a spatial phase singularity;
2. forming an illuminated spot and a standing wave having at least one bright fringe and at least one dark fringe on the substrate;
3. the bright fringe extending over at least a portion of the illuminated spot; and
4. detecting, by a dark-field optical detection system, scattered light from nano-defects.

The distinguishing element over the entire cited corpus is the combination of a spatial-phase-singular (Gauss–Laguerre-like) illumination beam with the resulting standing wave whose bright fringe is locked to the substrate surface. Dependent claims 2–14 and independent claims 15 and 20 carry the same core; claims 9–13/17–19 are the generic dark-field hardware recitations; claims 6, 7, 16 are the numeric/optional features.

Bottom line up front: On the record provided, no single cited reference discloses the full claim-1 combination, so true §102 anticipation is not established for claim 1 (or claims 15/20). The strongest §102 exposure is against the broad apparatus sub-claims (9–13, 17–19) and the generic method steps, where several dark-field inspection references individually disclose the recited hardware. The bulk of the corpus reads on §103 (obviousness), not §102.

2. TIER 1 — Most relevant prior art (the singular-beam / standing-wave core)

These are the only references that touch the actual point of novelty.

3. TIER 2 — Dark-field / bright-field wafer-inspection architecture (targets claims 8–13, 15–19)

These do not disclose a singular beam, but they disclose the dark-field illumination/collection architecture, TDI/PMT detection, relay optics, apertures, autofocus, and image computer that the dependent and system/apparatus claims recite generically. Individually they are the best §102 candidates only for the structural sub-claims.

4. TIER 3 — Peripheral / non-analogous references (little or no §102 value)

These appear in the citation list but, on the record, do not touch the singular-beam/dark-field inspection concept. Flagged so the analysis is complete:

• US 5781294 A — Nakata, Hitachi — photoacoustic signal detection (1991-12-24 / 1998-07-14).
• EP 0935772 A1 / B1 — Raytheon — objective lens with constant focal length in visible and IR (1997-09-04 / 1999-08-18; B1 2002-12-04). Relevant at most to the chromatic-aberration hardware (claim 11).
• US 2002/0106848 A1 — Dan Wack — determining a property of a specimen pre/during/post-lithography (2000-09-20 / 2002-08-08).
• US 2002/0109848 A1 — Hendriks — "Inspection of surfaces" (2000-11-20 / 2002-08-15).
• US 6504618 B2 and US 7006221 B2 — Rudolph Technologies — photoacoustic film-thickness / spectroscopic-ellipsometer metrology (2001-03-21 / 2003-01-07; 2001-07-13 / 2006-02-28).
• US 2005/0099633 A1 — Failes — fiber-optic scanning interferometer with polarization-splitting coupler (2003-11-06 / 2005-05-12).
• US 2013/0265572 A1 — KLA-Tencor — protective fluorine-doped silicon-oxide optical coating (2012-04-04 / 2013-10-10).
• US 7746469 B2 — P.M.L-Particles Monitoring Technologies — particle size/concentration measurement (2003-07-09 / 2010-06-29). Possibly relevant to scattered-light particle detection generally (note the Shamir lineage — see NPL above), but claims particle sizing, not wafer defect inspection.
• US 7,554,655 B2 related family entries, and US 2007/0070336 A1 (Maeda, manufacturing method for semiconductor substrate) — generic.
• Clearly non-analogous: US 2009/0081512 A1 (Blanchard, micromachined electrolyte sheet/fuel cell) and US 2009/0297725 A1 (Reynoldson, duplex surface treatment of metal objects) — cited by examiner but irrelevant to the claimed subject matter.

5. Foreign-family citations (Family Cites Families, 8)

6. Overall §102 assessment

1. Claim 1 / 15 / 20 (the singularity + surface-locked bright fringe): No cited reference discloses the full combination. US 4,893,932 supplies the standing-wave/bright-and-dark-fringe-on-the-substrate element (and claims 5–6 polarization/AOI); Hemo (2011) and van de Nes (2007) supply the singular-beam element. Anticipation would require improperly combining references — these are §103, not §102, references.

2. Claims 2–4 (two beam portions, π phase difference, phase mask/retarder): The singular-beam NPL (Hemo; van de Nes) and CN 104121996 A (vortex-beam device) are the closest; none of the cited patent art discloses a phase mask with a π phase jump for inspection illumination. Best read as §103.

3. Claims 9–13, 17–19 (dark-field detection system: objective, aperture, relay optics, bandpass filter, TDI/PMT array, autofocus, image computer): These are the claims most exposed to §102. US 6,288,780 / US 7,554,655 (KLA-Tencor) disclose TDI-based dark-field wafer inspection; US 8,912,495 (multi-spectral), US 2015/0226676 (combined BF/DF), and US 9,194,811 (sensitivity improvement) individually disclose most recited hardware. A strict §102 rejection of these dependent claims on a single reference is arguable.

4. Claim 7 (EUV/DUV/UV/visible): §102/§103 exposure to US 8,912,495 (multi-spectral, UV/DUV) and the spec's own Nd:YAG 266/355 nm discussion.

5. Claim 14 (defects atop substrate and all layers): §103 in view of US 2006/0215175 (Ler Technologies, surface/subsurface detection) and US 9,389,349 (depth determination).

6. Non-analogous citations (Blanchard fuel cell, Reynoldson metal treatment, Best radiant burner) carry no §102 weight and likely reflect automated citation capture.

Caveat on confidence: Descriptions for references I could not independently re-verify online (most of Tier 3 and Tier 2) are based on the patent's citation metadata and my background knowledge; treat their technical characterization as provisional. The two NPL articles and US 4,893,932 / US 6,288,780 were verified via live search. The "Cited By" lists in the record are predominantly post-2016 filings and are therefore not prior art to this patent (priority 2016-06-02); they were excluded from the §102 analysis.

I'll ground this analysis in the actual prior art of record before drafting. Let me pull details on the key references.

Obviousness Analysis — US 10,345,246 B2 under 35 U.S.C. § 103

Builds on the earlier bibliographic, claim-mapping, and prior-art sections. Where I rely on a reference's title/abstract only (because I could not retrieve full text), I say so.

1. Legal framework and the operative date

AIA applies. The application was filed 2017-06-01 and claims benefit of provisional 62/344,575 filed 2016-06-02. Both dates post-date 16 March 2013, so §§ 102/103 as amended govern, and prior art must qualify under § 102(a)(1) (patented, described in a printed publication, or in public use before the effective filing date) or § 102(a)(2). Every reference cited on the face of the patent (1986–2016) comfortably predates the 2016-06-02 effective date. Confidence: high.

Burden/forum. In district court, invalidity requires clear and convincing evidence. Before the PTAB, a petitioner needs only a preponderance to prevail, but must first get institution past § 314(a) and § 325(d). As noted in the earlier section, no IPR/PGR or litigation was found. Practical note: the two references most on point — Hemo 2011 and van de Nes 2007 — were cited in the ISR of 2017-08-11 and therefore appear in the "Non-Patent Citations" of record. A petition resting exclusively on them invites § 325(d) discretion (see Advanced Bionics/Becton Dickinson). A challenger should therefore lead with a combination that includes material not previously considered — e.g., US 9,194,811 (cited, but as a § 102 reference only) recast as the phase-engineering teaching, or the CN vortex-beam art from the family-citation list.

Level of ordinary skill (proposed). A POSITA here has an M.S. (or B.S. plus several years) in optics, applied physics, or EE, with 3–5 years' experience in optical wafer inspection, laser scatterometry, or singular-optics beam shaping. This is a fairly sophisticated artisan: the patent's own equations (1)–(5), the fringe-spacing relation h = λ/2cos θ, and the cot((2π/λ)x) intensity-ratio derivation are undergraduate-optics-level, and the beam-generation disclosure (flat-top shaping + π phase plate) is standard. Confidence: high.

2. Construction of the dispositive limitations

Flagged tension (carried from the earlier section): the grant text claims a "spatial phase singularity" while the specification's operative definition is a two-portion beam separated by π. If a tribunal adopts the specification's meaning, the claim covers the FIG. 4 π-step beam, and the obviousness case below is markedly stronger. If a tribunal instead requires an azimuthal vortex, the case is only slightly weaker (see §4.3).

3. Prior art of record — what each reference supplies

Not found: I could not locate, in the record as supplied, a reference that expressly discloses oblique collimated illumination forming a standing wave with a surface-locked bright fringe. That is the element the examiner evidently relied on for allowance. If such art exists (I suspect it does — standing-wave/scatterometric illumination for surface height and particle detection is an established technique), it would strengthen the case considerably, but I will not assert a specific reference I have not verified. Confidence in the negative: low–medium.

4. Proposed combinations

4.1 Primary combination — Combination A (dark-field platform + singular-beam measurement art)

US 6,288,780 B1 ∨ US 7,554,655 B2 (dark-field oblique laser wafer inspection) + Hemo 2011 + van de Nes 2007 (optionally + US 7,746,469 B2).

Element-by-element:

Motivation (KSR factors):

1. The problem was known and articulated in the art itself. Hemo 2011 opens by stating there is "mounting interest in better methods of measuring nanoscale objects … in microelectronics" and that "conventional methods have proved insufficient." That is the exact problem the '246 patent addresses.
2. The solution was a recognized, finite option. Hemo's entire thesis is that singular beams have "special characteristics with respect to the investigation of subwavelength objects" because the field varies strongly around the singularity. A POSITA seeking to illuminate a 5–20 nm defect more brightly has a small, identified set of options; a phase-singular beam is one of them.
3. Simple substitution with a predictable result. Substituting a phase-engineered beam for a Gaussian beam in a known oblique dark-field illuminator is a substitution of one known illumination field for another, with the result (change in the fringe/field structure at the surface) foreordained by the well-known interference relations h = λ/2cos θ and the cos-vs-sin surface term. KSR step 3 (obvious to try) applies squarely: the patent's own eq. (5), I_sing/I_Gauss = cot((2π/λ)x), is a closed-form prediction of the benefit — nothing unexpected is discovered.
4. Same field, same research lineage. van de Nes/Hemo/Shamir operate in particle-scattering optics; US 7,746,469 (Shamir) already claimed particle measurement using a synthesized non-Gaussian beam. The motivation to move structured-beam particle metrology into wafer inspection is a design incentive flowing from the references themselves, not hindsight.

4.2 Combination B — adding express phase-engineering in an inspection system

US 6,288,780 + US 9,194,811 + Hemo 2011. US 9,194,811 closes the gap between "scattering theory" and "inspection hardware": it teaches a coherent light source, oblique illumination, phase-shifting diffractive optical elements, mutually phase-shifted coherent beams, and — critically — that this improves background noise and SNR for semiconductor defect detection and that a known fringe profile can be subtracted to recover a real defect signal. A POSITA reading US 9,194,811 alongside Hemo's singular-beam proposal would need only routine adaptation to place a π-step phase element (the specification's own step height d = λ/2(n−1)) in the illumination path. This combination is the strongest for claims 2–4, which recite exactly "at least two beam portions separated by a phase difference … formed using a phase mask or a phase retarder."

4.3 Combination C — the vortex reading

If "spatial phase singularity" is construed as an azimuthal vortex (LG mode), the combination is: US 6,288,780 (∨ US 2015/0226676) + van de Nes 2007 + CN 104121996 A ∨ US 9,194,811 (SLM/DOE generation). van de Nes teaches GL beams and their particle scattering; CN 104121996 A teaches SLM generation of LG vortex beams from a Gaussian input. The motivation is unchanged (Hemo's subwavelength-object framing). Caveat: a vortex beam has a dark core on axis, which is in some tension with a bright fringe at the surface; a POSITA might prefer an off-axis or multi-order arrangement. That is an argument the patent owner could press, but it is an argument about optimization, which KSR treats as within the ordinary skill level. Confidence in this variant: medium.

4.4 Dependent claims

Because each dependent claim either tracks an element already in the primary combination or adds a routine, art-recognized design choice, the § 103 exposure of the dependent set is generally higher than that of the independents.

5. Anticipated rebuttals, and how they fare

1. "Unexpected results — a 3× intensity gain on a 17 nm particle." Weak. The patent derives this from a closed-form expression (eq. 5) rather than reporting an anomaly. Under KSR/In re O'Farrell, a result that follows predictably from the combination's known operation does not rebut obviousness. The magnitude (3–4×) is also a scale, not a new property.
2. "Simultaneous invention / non-obviousness of the insight." The patent's contribution is recognition that the surface-locked node of the Gaussian standing wave is dark and that flipping the beam phase puts a bright fringe there. Recognition of a previously unappreciated natural phenomenon, without more, does not confer patentability — and here the underlying optics were fully known and quantified.
3. "Teaching away." The references do not criticize singular-beam illumination. The patent's own disclosure that I_sing/I_Gauss < 1 for x > λ/8 is an argument the owner could deploy only against the embedded-layer claim (14), not against the surface-defect claims. Conversely, the Gaussian standing-wave art says nothing that would steer a POSITA away from a phase-engineered beam.
4. "No reasonable expectation of success." Weakest for the owner. The physics is deterministic and the intensity ratio is analytic; the aggregation of two known illuminator components is not unpredictable in the KSR sense.
5. Secondary considerations. No evidence of record ties commercial success, licensing, or a failure of others to the claimed bright-fringe mechanism (no nexus). Tokyo Electron's market position and the absence of observed litigation are not probative of non-obviousness.

6. Independent flag — an enablement/written-description vulnerability worth noting separately

Claim 14 extends to "defects located atop the substrate and all layers formed on the substrate." By the patent's own equation (5), the singular beam's intensity advantage holds only for x < λ/8 and inverts beyond that. For embedded defects deeper than a small fraction of a wavelength, the disclosed mechanism affirmatively loses signal relative to Gaussian illumination. This is a § 112(a) question (and, at minimum, an argument that claim 14's full scope is not enabled), distinct from — and in some ways more promising than — the § 103 attack on it. It also gives the owner a narrow retort: the surface claims, not claim 14, are the commercially meaningful ones.

7. Bottom line

• § 103 exposure is substantial for independent claim 1 and for claims 2–14, and derivative for claims 15–20. The strongest, cleanest combination is US 6,288,780 B1 (or US 7,554,655 B2) as the dark-field wafer-inspection platform + Hemo 2011 and/or van de Nes 2007 for the singular-beam illumination and its stated motivation to measure subwavelength objects in microelectronics +, preferably, US 9,194,811 B1 for the express teaching of phase-shifting optics and phase-shifted coherent oblique illumination to improve defect SNR.
• The motivation is unusually well documented in the art itself (Hemo 2011's own framing), which mitigates hindsight concerns.
• The principal weakness of any challenge is procedural, not substantive: the two most on-point references were before the examiner via the 2017 ISR, so a PTAB petition built solely on them risks § 325(d) discretionary denial; and no IPR or litigation has been filed, so the patent currently enjoys both a presumption of validity and the absence of any adverse post-grant record.
• I could not verify the full text of US 7,746,469, the Japanese/Korean references, or (critically) any reference expressly disclosing a standing wave with a surface-locked bright fringe in an inspection context. My § 103 conclusions therefore rest on the retrieved abstracts and passages cited above; the element-by-element mappings marked "medium" or "medium–high" should be confirmed against full reference texts before this analysis is relied upon in a validity opinion or petition. Confidence in the overall § 103 conclusion: medium-high, contingent on that verification.