US 7045841

I'll search for authoritative information on US patent 7,045,841.

Let me search more specifically for litigation/docket records and the patent's assignee history.

Let me check for litigation, PTAB, or Federal Circuit activity involving this patent.

US Patent 7,045,841 — Summary

Important caveat up front: I have the full authoritative patent text (source: https://patents.google.com/patent/[US7045841](/patent/US7045841)/en, fetched 2026-09-24). My searches did not return any USPTO litigation docket, PTAB proceeding, or CAFC 2026 docket entry involving patent 7,045,841. I could not directly query PACER/CAFC's docket system or USPTO Patent Public Search in this environment, so I cannot rule out pending activity — I simply found no authoritative record of it. I will not assert a litigation status I can't verify.

Bibliographic data

Because this is a divisional of US 6,974,708, the method claims appear to reside in the parent; this patent's independent claim is drawn to the device.

Abstract (verbatim)

"An MTJ (magnetic tunneling junction) MRAM (magnetic random access memory) has a tunneling barrier layer of substantially uniform and homogeneous Al₂O₃ stoichiometry. The barrier layer is formed by depositing Al on a CoFe layer or a CoFe—NiFe bilayer having an oxygen surfactant layer formed thereon, then oxidizing the Al by radical oxidation. The underlying surfactant layer contributes oxygen to the bottom surface of the Al, forming an initial amorphous Al₂O₃ layer. This layer produces small, uniform grains in the remaining Al layer, which promotes a uniform oxidation of the Al between its upper and lower surfaces by the subsequent radical oxidation. A final annealing process to set a pinned layer magnetization enhances the homogeneous oxidation of the layer."

Plain-language overview of the independent claim (Claim 1)

Claim 1 recites a magnetic tunneling junction (MTJ) device in an MRAM configuration, comprising, in stacked order:

1. A substrate, with a conducting lead layer on it that includes a Ta capping layer whose upper surface has been sputter-etched (the specification says ~20–30 Å removed from an originally 80–100 Å Ta layer to promote smoothness).
2. An NiCr seed layer on the sputter-etched surface (claim 2 specifies 35%–45% Cr by atom number).
3. A bottom electrode on the seed layer, itself comprising (a) an antiferromagnetic pinning layer and (b) a synthetic antiferromagnetic pinned (SyAP) layer made of lower and upper ferromagnetic layers magnetized in antiparallel directions, separated by a coupling layer (claims 4–7 specify CoFe(25%) upper / CoFe(10%) lower / Ru coupling, or a CoFe(10%)–NiFe(60%) composite upper layer).
4. An oxygen surfactant layer (OSL) previously formed on the upper ferromagnetic layer.
5. A smooth, stoichiometrically homogeneous oxidized-aluminum tunneling barrier layer of uniformly small grain size, formed on the OSL and having absorbed the oxygen of the OSL (claim 8: the OSL is "less than a monolayer of oxygen"; claim 11: Al deposited by PVD to ~7–10 Å and oxidized by radical oxidation to Al₂O₃ stoichiometry).
6. A ferromagnetic free layer on the barrier layer (claims 12–13 specify CoFe(25%)–NiFe(20%) or NiFe(60%)–NiFe(20%) bilayers).
7. A capping layer on the free layer.

The core inventive concept captured by claim 1: oxygen is supplied to the aluminum barrier from both sides — the plasma/radical oxidation from above and the pre-formed oxygen surfactant layer from below — yielding a more uniform Al₂O₃ barrier with small, uniform Al grain size, which the patent associates with higher DR/R and higher breakdown voltage.

Note on a discrepancy in the source text (not auto-corrected): The Google Patents "Definitions" extract cites "Gallagher et al. U.S. Pat. No. 5,640,373," while the patent body and the citation list give 5,640,343. I am flagging both as they appear rather than reconciling them.

Uncertainty / limits of this answer

• No litigation or 2026 CAFC docket record for 7,045,841 was found in my searches. I cannot confirm or deny active 2026 proceedings.
• Assignee history is taken from Google Patents' record (Headway → TSMC, 2019); I did not independently verify the assignment reel/frame (048692/0917 is cited in the source).
• Inventor name appears both as "Cheng T. Hong" (Google Patents) and "HORNG, CHENG T." (USPTO assignment records) — I have not auto-corrected either.
• The patent is expired (anticipated 2024-04-08), so any 2026 CAFC appeal would relate to a dispute over past damages/validity rather than an injunction, which is plausible but unverified here.

I'll research litigation involving US patent 7045841 using targeted searches.

Let me try more targeted searches on litigation databases and related parties.

Let me try more specific searches including the patent's litigation portal pages and related family patents.

Summary of Findings

No litigation involving U.S. Patent No. 7,045,841 was found. Based on the searches I was able to run (covering Unified Patents' litigation/PTAB portals, RPX Insight/ litigation documents, CourtListener/RECAP, Docket Alarm, and general web searches for the patent number and its assignees), I could not identify any district court action, ITC investigation, or PTAB proceeding (IPR/PGR/CBM) asserting or challenging this patent.

I want to be explicit about the limits of this conclusion rather than overstate it:

• I was unable to retrieve a Unified Patents litigation-portal page or an RPX/ Docket Alarm page specifically keyed to patent number 7045841. The searches for the number returned unrelated patents (e.g., 6,066,584; 7,534,584; and the Intellectual Ventures "'841" patent, which is a different patent — U.S. Patent No. 8,234,841 — and must not be confused with 7,045,841).
• Absence of a search hit is not proof of absence of litigation. Free/public databases have gaps, and older cases (this patent issued in 2006 and expired in 2024) may be incompletely indexed.

Patent Context (for reference)

Litigation Table

Caveats and Recommended Next Steps

Because the searches I could complete did not confirm any case, and because I am required not to fabricate case numbers or party names, I am reporting no known litigation rather than supplying a case list.

For a definitive answer, I'd recommend confirming directly against paid/complete sources:

1. Unified Patents litigation portal — https://portal.unifiedpatents.com/litigation/caselist (query by patent number 7045841).
2. Docket Alarm and Docket Navigator — search 7045841 across district courts and PTAB.
3. USPTO Patent Trial and Appeal Board (PTAB) endpoint / Patent Public Search "litigation" tab, to catch any IPR/PGR.
4. PACER / CourtListener RECAP — full-text docket search for 7,045,841.
5. RPX Insight — for defensive-aggregator or NPE assertions.

One relevant negative signal: a Stanford NPE-litigation database entry for Headway Technologies shows it primarily as an alleged infringer (e.g., Reiber v. TDK Corp., 2:11-cv-01057, E.D. Cal., Apr. 19, 2011) rather than as an asserting patent owner, and that case does not involve the '841 patent. The Google Patents page for '841 lists cited-by references (later TSMC, Samsung, Headway patents) but no "litigation" entries, consistent with there being no known suits.

Bottom line: On the available evidence, there is no known litigation involving U.S. Patent 7,045,841. This should be verified against a complete commercial litigation database before being relied upon, since my public-source searches were inconclusive as to exhaustive coverage.

I'll start by verifying the structured ODP data against public sources, since the canonical block indicates no AIA trial activity.

The generic searches returned nothing on point. Let me narrow to this patent family and potential litigants.

Let me try a couple more angles, including the PTAB docket style and litigation history.

Proceedings overview

Zero AIA trial proceedings are on file for US 7,045,841. The canonical ODP block supplied in this prompt reports no AIA trial proceedings, and independent web searches (PTAB dockets, USPTO PTACTS, Google Patents/Justia family pages, litigation coverage) surfaced no IPR, PGR, or CBM naming this patent — no petitioner, no institution decision, no FWD, no settlement, no appeal. Because the record is empty, none of the per-proceeding fields below can be populated; I will not invent proceeding numbers or outcomes.

The defensive posture this gives a defendant is unusual and worth stating plainly: the patent was never tested at the PTAB at all, and it is now expired. The ODP legal-status field reads "Expired - Lifetime," with an anticipated expiration of 2024-04-08 (20 years from the 2004-04-08 priority/filing date of parent application 10/820,391). There is no "hardened by two IPRs" narrative here, and there is no "claims canceled" narrative either — the entire claim set 1–13 is untested and un-narrowed by any administrative trial, but the patent's term has run out. See the family and status data at https://patents.google.com/patent/US7045841/en.

No proceedings to report

No AIA trial proceeding of any type (IPR / PGR / CBM) has been identified for US 7,045,841. I decline to list a fabricated "none" entry with invented docket details.

• Type: N/A
• Filed: N/A
• Status: Verbatim from the structured data: no AIA trial proceedings returned by the USPTO Open Data Portal.
• Judge panel: N/A
• Petition grounds: N/A
• Institution decision: N/A — no Director or Board institution decision exists for this patent.
• Final Written Decision: N/A — no claim of this patent has ever been canceled or confirmed in an AIA trial.
• Settlement / termination: N/A
• Appeal: N/A — with no FWD, there is no PTAB appeal to the Federal Circuit. I found no CAFC docket or CourtListener entry involving US 7,045,841.
• Defensive value: A defendant cannot point to any canceled claim, and a patent owner cannot point to any PTAB victory. The decisive fact is the expiration date, not an administrative-trial outcome.

Confidence note: I have high confidence that no IPR/PGR/CBM appears in the ODP structured data, which I treat as authoritative per the task instruction. My web-search corroboration is moderate — public docket aggregators are imperfect, and a very recent or unusually obscurely captioned filing could theoretically evade these searches. I found nothing to suggest one exists. (Also note: PGR was never available against this patent; it is pre-AIA, filed 2004.)

Strategic summary

Claim status. All 13 claims of US 7,045,841 are UNTESTED. Independent claim 1 (the MTJ/MRAM device with a sputter-etched Ta capping layer, NiCr seed layer, SyAP pinned structure, an oxygen surfactant layer, and a radical-oxidation Al barrier of "uniformly small grain size") and dependent claims 2–13 stand exactly as issued. No claim is canceled, none is confirmed by the Board, and none has been construed by the PTAB. The practical corollary matters more than the PTAB column: with expiration on 2024-04-08, the patent can only support past damages within the 35 U.S.C. § 286 six-year lookback measured from the date a complaint is filed. A complaint filed today could at most reach conduct back to 2020-10-01, and only up to 2024-04-08. Note the subsidiary estate for which the same point holds: parent US 6,974,708 (from which this patent is a division) shares the identical 2024-04-08 expiration.

Estoppel landscape. There is no § 315(e)(2) estoppel against anyone, because estoppel attaches only upon a final written decision and no FWD exists. That cuts both ways for a defendant: no one is barred, but there is also no pre-packaged invalidity record to borrow. IPRs against an expired patent are legally permissible (the Board construes expired claims under the Phillips framework and can still cancel claims to eliminate past-damages exposure), so a § 102/§ 103 IPR remains formally available if a demand is backed by a live damages theory. The § 315(b) one-year bar applies only if the defendant has been served with a complaint alleging infringement — a demand letter alone does not start that clock.

Pattern signals. None of the classic signals are present: no petitioner filed (so no repeat petitioner), no general-plastic or follow-on petition dynamics, no defensive aggregator (Unified Patents or similar) is in the chain, and no patent-owner PTAB appeal strategy exists because there was no PTAB case. The chain of title that would matter to a buyer or a troll is documented — the patent moved Headway Technologies / Applied Spintronics → Magic Technologies → Headway → Taiwan Semiconductor Manufacturing Company, Ltd., with the TSMC assignment recorded effective 2019-02-04 (reel 048692/0917). That makes TSMC the current owner of an expired MRAM barrier-layer patent, which plausibly explains the absence of AIA activity: as the practice moved to MgO barriers, this Al₂O₃/oxygen-surfactant disclosure simply aged out of commercial relevance. Also relevant to any future filing: the proposed PTAB rules published 2025-10-15 would bar an IPR where the patent already survived a validity challenge elsewhere and would add a "settled expectations" discretionary factor disfavoring institution on long-lived patents — an expired 2004 patent would sit at the far end of both considerations.

Recommended next steps

• If you are a defendant and no AIA trial exists, do not manufacture one in your narrative. Say so plainly: "No IPR, PGR, or CBM has ever been filed against US 7,045,841; the claim set is untested." The absence is itself a signal — well-asserted, commercially valuable patents eventually attract IPRs, and this one never did.
• Lead with expiration, not with PTAB. The strongest, cheapest defense is the calendar: the patent expired 2024-04-08, so demand recovery is capped by 35 U.S.C. § 286 and confined to the pre-expiration window. Verify the term calculation against the parent (application 10/820,391, filed 2004-04-08, U.S. Pat. No. 6,974,708) and confirm no terminal disclaimer, PTA, or reissue altered the date. Confirm ownership current at TSMC via the assignment records before negotiating.
• If a live past-damages theory is asserted, an IPR is still available. Use the patent's own cited art as the starting corpus — the eight references of record, including Gallagher US 5,640,343, IBM's US 2002/0081753, Infineon's US 6,864,175, and Headway's own US 6,703,654, plus the non-patent literature (Parkin 1999; Ando, J. Phys. D 35:2415 (2002); Shim, Appl. Phys. Lett. 83:4583 (2003); Nakashio, IEEE Trans. Mag. 36:2812 (2000); Egelhoff, J. Appl. Phys. 82:6142 (1997)). The oxygen-surfactant concept was already in the literature (Egelhoff), which is a natural § 103 attack vector. But weigh the cost: median electrical/computer IPR spend runs to roughly $350K through hearing and $500K+ through appeal, against a shrinking damages window.
• Watch § 315(b). If your client has been served with a complaint on this patent, the one-year IPR bar is running; if only a demand letter has arrived, it is not, and the patent's expired status means there is little to gain by filing preemptively.
• Monitor for anything ODP may have missed. I found nothing, but if you want a belt-and-suspenders check, search the PTAB E2E docket and PTACTS for the patent number and the "7,045,841"/"7045841" strings, and CourtListener for any CAFC appeal. To date, both return blank for this patent.

I'll research the assignment record for this patent. Let me start with targeted searches.

Let me dig into the corporate identities and the trustee/assignment details.

US 7,045,841 B2 — Ownership Chain Reconstruction

Data-integrity note up front: The four US assignments below are taken from the Google Patents legal-events record (fetched from the authoritative patent text). I was not able to retrieve the USPTO Assignment Center abstract pages themselves, and none of the sources I could obtain expose the "correspondent of record" field (the recording attorney/firm). I therefore cannot report correspondents without fabricating them — that field is flagged as a data gap rather than filled. Reel/frame numbers below are as recorded.

Inventors

• Both inventors assigned their rights jointly to Headway Technologies, Inc. and Applied Spintronics, Inc., per assignment effective 2004-03-17 (recorded 2018-10-25, Reel 047321/0485). This confirms the two companies as co-employers/co-owners at the time of filing.
• Unusual pattern — late inventor recording, not inventor departure. The notable anomaly is recording latency, not attrition: the inventor→company assignment was executed on 2004-03-17 but not recorded until 2018-10-25 — ~14.5 years later, in the same week as the downstream Applied Spintronics/Magic/Headway recordings. All four links in the chain were "cleaned up" on paper in a 5-month window (Oct 2018 – Mar 2019), immediately before the company-to-TSMC transfer. That is a classic pre-acquisition title-curative pattern.
• No evidence found of either inventor departing the original assignee within 12 months of filing, and no evidence either became a named principal in any downstream assignee (Horng and Tong continue to appear as Headway/Magic inventors on later MRAM filings — e.g., US 7,838,436 and US 8,273,666, per Patent Leaderboard). No fire-sale precursor signal from inventors.

Original assignee

Headway Technologies, Inc. (678 S. Hillview Drive, Milpitas, CA 95035) and Applied Spintronics, Inc. (Suite 100, 830 Hillview Court, Milpitas, CA 95035) — jointly, per the issued patent and the Reel 047321/0485 assignment.

• Headway Technologies — Milpitas magnetic-recording-head manufacturer; wholly owned subsidiary of TDK Corp. TDK's own annual reports list Headway under "Magnetic Application Products" with 100% (100%) voting rights. Headway was not bankrupt and did not dissolve; it continued to operate under TDK well after the 2019 patent transfer.
• Applied Spintronics, Inc. — a Milpitas MRAM technology/holding house. CB Insights describes it as "Provider of MRAM technology products… owns many important patents in MRAM device and technology." Note that two similarly named co-located entities exist: "Applied Spintronics, Inc." and "Applied Spintronics Technology, Inc.", both at 830 Hillview Court, Milpitas — a naming inconsistency that matters for the chain (see timeline link 2).
• Product embodying the claims? Unclear. US 7,045,841 claims a fabricated MTJ/MRAM structure and its method; neither Headway (heads) nor Applied Spintronics/Magic Technologies demonstrated a confirmed commercial MRAM product on the record I could obtain. This is an MRAM IP/design portfolio, not evidence of a shipping product.
• Current status: Headway remains an operating TDK subsidiary; the MRAM patent portfolio transferred to TSMC in 2019 (Reel 048692/0917).

Assignment timeline

All four recorded assignments post-issuance, in chronological order by effective date:

• 2004-03-17 (executed) / recorded 2018-10-25 — Reel 047321/0485

  • Conveyance: Assignment
  • Assignor: Horng, Cheng T.; Tong, Ru-Ying
  • Assignee: Applied Spintronics, Inc. (California) and Headway Technologies, Inc. (California)
  • Correspondent: not available — the Google Patents legal-events record does not expose the recording correspondent, and the Assignment Center abstract pages could not be retrieved. (Repeat-player check: cannot be performed — data gap.)
  • Context: Original inventor employment/JSA assignment, belatedly recorded 14.5 years later as part of a title-curative effort ahead of the TSMC deal.

• 2007-10-19 (effective) / recorded 2018-11-02 — Reel 047391/0493

  • Conveyance: Assignment
  • Assignor: Applied Spintronics Technology, Inc.
  • Assignee: Magic Technologies, Inc. (California; 463-471 S. Milpitas Blvd.)
  • Correspondent: not available (data gap)
  • Context: Internal corporate consolidation — an Applied Spintronics entity folded into Magic Technologies. ⚠️ Name mismatch to flag: the assignor here is "Applied Spintronics Technology, Inc.", whereas the original co-assignee was "Applied Spintronics, Inc." — same street address, different legal name; a title examiner should confirm they are the same (or linked) entity.

• 2018-11-13 (effective) / recorded 2018-11-20 — Reel 047604/0081

  • Conveyance: Assignment
  • Assignor: Magic Technologies, Inc.
  • Assignee: Headway Technologies, Inc. (California)
  • Correspondent: not available (data gap)
  • Context: Internal reorg/consolidation — Magic Technologies reabsorbed into Headway. (Corroborated on the EP side for the sibling family member EP1801810, whose register records Headway substituted for Applied Spintronics + Magic Technologies "by virtue of deed of assignment.")

• 2019-02-04 (effective) / recorded 2019-03-25 — Reel 048692/0917

  • Conveyance: Assignment
  • Assignor: Headway Technologies, Inc.
  • Assignee: Taiwan Semiconductor Manufacturing Company, Ltd. (Taiwan)
  • Correspondent: not available (data gap)
  • Context: Portfolio acquisition by a large operating foundry — TSMC acquiring Headway's MRAM patent family (the MRAM group was ramping at TSMC in this period).

Single weak, non-dispositive correspondent lead (NOT a US recording correspondent): the UK/EP register for sibling patent EP1801810 shows address-for-service changes handled by Cabinet Thierry Schuffenecker, F06800 Cagnes-sur-Mer, France, for Magic Technologies in 2010. This is a European representative, not the US assignment correspondent, and appears only once — not a repeat-correspondent finding.

Timeline diagram

timeline
    title Ownership of US 7045841
    2004 : Priority application filed
    2005 : Divisional application filed
    2006 : Issued to Headway and Applied Spintronics
    2018 : Inventor assignment recorded
         : Applied Spintronics moves to Magic
         : Magic Technologies moves to Headway
    2019 : Headway Technologies to TSMC
    2024 : Patent expires

NPE / troll-pattern signals

Verdict

Defensive / non-asserting (closest available fit — see caveat)

The chain contains zero NPE signals: the patent moved inventors → Headway (a solvent TDK subsidiary) / Applied Spintronics → internal Milpitas consolidations → back to Headway → TSMC (Reels 047321/0485, 047391/0493, 047604/0081, 048692/0917), with no shell LLC, no known asserter, no litigation, and no bankruptcy. The only notable pattern is the five-month late-recording cluster (Oct 2018 – Mar 2019) that cleaned up title immediately before the TSMC acquisition — a title-curative/pre-acquisition signature, not a troll signature. The patent expired 2024-04-08 and is not being asserted.

Caveat: TSMC is a large practicing operating company, not a textbook defensive aggregator, so "Defensive / non-asserting" fits the substance (non-asserting, held by an operating company) rather than the letter of the category. It is the correct anti-NPE call; "Operating-company assertion" would be wrong because there is no documented suit against a competitor.

Verification: USPTO Patent Assignment Search — https://assignmentcenter.uspto.gov/ (or https://assignment.uspto.gov/patent/index.html) — search patent number 7045841; reels to pull: 047321/0485, 047391/0493, 047604/0081, 048692/0917. Recommended next step: pull those four abstract pages to capture the recording correspondent, which is the one field needed to complete signal #3 and confirm whether a single attorney handled the 2018–2019 cluster.

I'll research the prior art citations for US 7,045,841, starting with targeted searches on the patent and its cited references.

Let me gather details on the IBM references and the two Headway application publications cited.

Prior-Art Analysis — US 7,045,841 B2

Scope note: I searched for the patent number 7045841 and confirmed a single clean hit on US 7,045,841 B2 (Google Patents, fetched 2026-09-24). No similar-number conflation occurred in the results, and the earlier "Definitions" typo (Gallagher "5,640,373") is confirmed — the real, verified reference is US 5,640,343. The citation sets below are taken from the '841 front page ("Patent Citations (8)" and "Non-Patent Citations (8)") and were spot-verified for several references.

Legal framework used: The '841 application was filed 2005-11-07 (pre-AIA), claiming benefit of 2004-04-08 (parent 10/820,391). Pre-AIA 35 U.S.C. §102 therefore governs. Because it is a divisional, the effective date and the §102(b) one-year critical date run from the earliest US filing in the chain (2003-04-08 for §102(b); 2004-04-08 for §102(a)/invention-date and §102(e) analysis). A reference anticipates a claim only if it discloses every element of that claim in a single reference (no reliance on a second reference for missing elements).

Key structural threshold for claim 1 (from the previously generated summary): (a) substrate; (b) conducting lead w/ sputter-etched Ta capping layer; (c) NiCr seed; (d) bottom electrode = AFM pinning + SyAP (lower/upper FM separated by coupling); (e) oxygen surfactant layer (OSL); (f) smooth, stoichiometrically homogeneous oxidized-Al barrier of uniformly small grain size, "having absorbed the oxygen" of the OSL; (g) free layer; (h) capping. No single cited reference has all eight.

A. The eight patent citations — availability and description

B. Reference-by-reference §102 analysis

1. US 5,640,343 A — Gallagher et al. (IBM), 1997-06-17 — §102(b)

Description: Foundational MRAM patent. An array of MTJ cells, each = pinned layer / insulating tunnel barrier / free layer, with the barrier formed of e.g. oxidized Al (Al₂O₃ appears among its materials). Discloses the generic MTJ-MRAM "device in an MRAM configuration."
§102 analysis: This is background that anticipates nothing in the '841 claims. It lacks the sputter-etched Ta capping layer (claim 1 element b), the NiCr seed (c), the SyAP with a coupling layer (d), the OSL (e), and the small-grain, homogeneity-limiting barrier "having absorbed the oxygen" of the OSL (f). No claim anticipated. Its relevance is confined to the claim-1 preamble ("MTJ device in an MRAM configuration") and to demonstrating the state of the art.

2. US 2002/0081753 A1 — IBM, 2002-06-27 — §102(b)

Description: "Formation of arrays of microelectronic elements" — array/integration subject matter, not MTJ barrier chemistry or bottom-electrode structure.
§102 analysis: Discloses none of the distinguishing elements of claim 1 (no OSL, no SyAP, no NiCr seed, no sputter-etched Ta). No claim anticipated. Background only.

3. US 6,331,944 B1 — Parkin/Monsma et al. (IBM), 2001-12-18 — §102(b)

Description: MRAM using a series tunnel-element select mechanism — again an array/circuit-architecture reference.
§102 analysis: Does not disclose the claimed stacked-layer barrier structure or OSL. No claim anticipated.

4. US 6,864,175 B2 — Infineon, 2005-03-08 — §102(e) (US filing 2001-09-20)

Description: Fabrication of tunnel-contact elements in which the barrier/contact layers are formed by electrochemical deposition / anodic oxidation, with mask-layer processing (mask overlap, reentrant sidewalls) — a very different manufacturing route from PVD Al + radical oxidation.
§102 analysis: Even setting aside its different field, it does not disclose the PVD-Al-then-radical-oxidation barrier of claim 11, nor the OSL, SyAP, NiCr seed, or sputter-etched Ta of claim 1. No claim anticipated. Relevant at most as §102(a)/(b)-type evidence that tunnel barriers were generally known.

5. US 6,703,654 B1 — Tong & Horng (Headway), 2004-03-09 — most structurally relevant, but same inventive entity

Description: A bottom conductor electrode for an MTJ built on a NiCr seed layer, with an MTJ stack of MnPt pinning layer / CoFe–Ru–CoFe pinned layer / AlOx tunneling layer / CoFe/NiFe free layer. It expressly discloses the NiCr seed and a synthetic (CoFe–Ru–CoFe) pinned layer — i.e., it maps onto claim 1 elements (c) and (d), and to claims 3, 4, 6.
§102 analysis — important nuance: This reference is very close structurally to claims 1/3/4/6, and if it disclosed the OSL it would be the strongest anticipation candidate. However:

• It does not disclose the OSL (element e) or the barrier "having absorbed the oxygen" of an OSL (element f), nor the sputter-etched Ta capping layer (element b). So it does not anticipate claim 1 (or its dependents, which incorporate all claim-1 elements).
• Its inventors (Tong, Horng) are the same inventive entity as the '841 inventors. As such it is not available as §102(e) art (which requires "by another"), and its same-entity status also complicates any §102(a) "by others" theory.
• Its real value is as §102(a)/(b) or §103 evidence of the then-known bottom-electrode/SyAP architecture — not as an anticipatory reference.

6. US 2005/0057863 A1 — Headway, 2005-03-17 — §102(e) (US filing 2003-09-12)

Description: Spin-valve head fabrication. Per the '841 specification, the corresponding Headway work (HT 03-006) discloses sputter-depositing a layer with oxygen-doped argon so that the incorporated oxygen migrates to the surface to form an OSL — the alternative OSL-formation route recited in the '841 disclosure.
§102 analysis: It is directed to GMR/spin-valve read sensors, not an MTJ-MRAM device; it does not disclose claim 1's NiCr seed, sputter-etched Ta capping, SyAP, or the homogeneous oxidized-Al barrier. No claim anticipated. Relevant to the method of forming the OSL (claim 8 subject matter) and as §103 art.

7. US 2005/0170532 A1 — Headway, 2005-08-04 — §102(e) (US filing 2004-01-30)

Description: "Novel oxidation method to fabricate low resistance TMR read head" — an oxidation/OSL method aimed at low-RA barriers (this corresponds to related Ser. No. 10/768,917 listed in the '841 body). Its subject matter overlaps the OSL → Al-oxidation → homogeneous barrier core of claims 8 and 11.
§102 analysis: Its title and framing place it in the TMR read-head context, and it does not disclose the full MRAM stack of claim 1 (sputter-etched Ta capping, NiCr seed, SyAP-with-coupling structure). No claim anticipated. Because it is co-owned common-assignee work, any §103 combination with it would also implicate the common-ownership disqualification — worth noting, but it is unavailable as anticipation.

8. US 6,960,480 B1 — Headway, 2005-11-01 — NOT §102 prior art against '841

Description: An MTJ-MRAM/TMR method using a novel seed layer to obtain a smooth ultra-thin barrier; its stack includes a Ta seed, NiFe/CoFe free layer, CoFe/Ru/CoFe pinned layer, AFM (PtMn) pinning layer, Ta capping, and a barrier discussed as oxidized NiCr (NiCrOx).
§102 analysis: This reference is structurally close and would otherwise be a strong §103 candidate. But its US filing date is 2004-05-19, i.e., after the '841 priority date of 2004-04-08. A pre-AIA §102(e) reference must predate the applicant's invention; a reference patented/published after the critical date cannot be §102(a)/(b) art either. It is therefore not prior art to the '841 claims and anticipates nothing. Its appearance in the front-page citation list should not be read as making it anticipatory. (It also lacks the OSL.)

C. Non-patent citations — the most relevant of the "other" prior art

These are frequently the references of greatest substantive relevance, even though they are printed publications rather than patents:

D. Bottom line — most relevant prior art and §102 conclusions

1. No cited reference anticipates any claim of US 7,045,841. Anticipation requires a single reference disclosing all elements of the claim. Claim 1 requires the combination of a sputter-etched Ta capping layer, an NiCr seed, an SyAP pinned layer with a coupling layer, an OSL, and a smooth, stoichiometrically homogeneous oxidized-Al barrier of uniformly small grain size that "absorbed the oxygen" of the OSL. No one reference has this combination; the dependent claims inherit the same deficiency.

2. The most relevant prior art, in order:

   • Egelhoff (1997) — the oxygen-surfactant concept (NPL); the closest conceptual teaching for the OSL that distinguishes the claims. Best §103 material.
   • US 6,703,654 B1 (Tong/Horng, Headway) — closest structural reference (NiCr seed + MnPt + CoFe/Ru/CoFe + AlOx + CoFe/NiFe), but same inventive entity and lacking the OSL. §102(a)/(b)/§103 weight only.
   • US 2005/0170532 A1 and US 2005/0057863 A1 (Headway) — the OSL/oxidation method references (claims 8, 11 subject matter); §102(e)-eligible but no full-stack teaching.
   • Nakashio (2000) — CoFe(25%)/Al-oxide/CoFe magnetoresistance (claims 4, 9).
   • Gallagher '343, Parkin '944, and Parkin/Tehrani/Fujikata NPL — general MTJ-MRAM background only (preamble-level).

3. Two citations on the '841 front page are not prior art at all:

   • US 6,960,480 B1 — filed 2004-05-19, after the 2004-04-08 priority date.
   • U.S. Appl. No. 10/844,171 (listed as NPL) — filed 2004-05-12, also after the priority date.
     Neither can anticipate or otherwise qualify under §102.

4. §102 subsection availability summary: the only cleanly §102(b)-qualified references are Gallagher '343, IBM '753, Parkin '944, Infineon '175 (via §102(e)), US 2005/0057863 and US 2005/0170532 (via §102(e)), and the pre-April-2003 NPL (Parkin 1999, Nakashio 2000, Fujikata 2001, Tehrani 1999, Ando 2002, Egelhoff 1997). Shim (2003-12-01) is at best §102(a). US 6,703,654 raises same-inventive-entity concerns for §102(e).

Caveat / limits: I confirmed the citation lists and several individual references via web search and the authoritative patent text, but I could not run a live USPTO Patent Public Search / PatentCenter "references cited" query in this environment. The §102 subsection/date classifications above are my analytical assignments from the dates shown and should be confirmed against the '841 file wrapper (IDS and examiner's cited-reference list) before being relied on. I did not locate any reference that anticipates the claims, and I am not asserting one exists among these citations.

I'll analyze obviousness under § 103 using the prior art cited on this page. Let me first verify the content of the key references.

Obviousness Analysis — U.S. Patent 7,045,841 under 35 U.S.C. § 103

Building on the earlier summary and litigation sections; I do not repeat the bibliographic/claim overview except where needed for cross-reference.

1. Governing legal framework and critical date

• Statute: This patent issued 2006-05-16 from App. No. 11/268,352 (filed 2005-11-07), a divisional of 10/820,391 (filed 2004-04-08). It is therefore governed by pre-AIA § 103, with an effective filing/invention date presumptively of 2004-04-08.
• Standard: Graham v. John Deere factors — scope/content of the prior art, differences, PHOSITA level, and objective evidence. Because the analysis is performed today, KSR Int'l v. Teleflex also applies: motivation to combine may be found in the references, in the problem itself, or in common knowledge; an explicit teaching-suggestion-motivation is not required, and a predictable solution from a finite set of identified options is obvious.
• PHOSITA: a person with an advanced degree or equivalent experience in magnetic thin-film devices / spintronics, familiar with MTJ/TMR stack design, PVD, plasma/radical oxidation, and MRAM integration.

§ 102 threshold note: One listed citation — US 6,960,480 B1 (Headway; priority 2004-05-19, granted 2005-11-01) — post-dates the 2004-04-08 priority date and therefore is not § 102 prior art to the claim-1 subject matter (it is, at most, an integrity/"family" citation). Similarly, the related Headway application HT 03-022 / Ser. No. 10/844,171 (filed 2004-05-12), is not prior art on its face. I flag these so they are not miscited as prior art in a § 103 rejection.

2. The prior art of record (from the page's Prior Art section)

Applicant-Admitted Prior Art (AAPA): The '841 specification itself admits that (i) ROX is "normally used for the oxidation method," (ii) "the MRAM film stack [is] thermally annealed," (iii) "CoFe with 25% Fe … yields a higher DR/R than CoFe with 10% Fe," and — critically — that the oxygen surfactant layer (OSL) "is discussed in related Applications HT 02-032 and HT 03-006, both of which are fully incorporated herein by reference," describing it as "a sub-monolayer of oxygen adsorbed on the surface of a deposited layer." AAPA is usable in § 103. This is a significant admission: the OSL concept is not, on the applicant's own account, novel per se.

3. Claim 1 mapped to the references

Claim 1 is the only independent claim and covers a device. Mapping (element ⇒ reference):

No single reference discloses every element (especially the combination of sputter-etched Ta + NiCr seed + SyAP + OSL-under-Al + ROX), so this is a § 103, not § 102, case. The dependent claims (2–13) recite only conventional parameters (Cr content of NiCr 35–45 at.%; MnPt/IrMn; CoFe(25%)/Ru/CoFe; layer thickness ranges; free-layer bilayers) — all squarely within the cited art.

4. Combinations that render claim 1 obvious

Combination I — Primary: Parkin/Tehrani/Gallagher + Egelhoff + Ando/Shim (+ Nakashio)

• Parkin (1999) and Gallagher '343/Tehrani supply the entire MTJ-MRAM cell architecture: an AFM-pinned ferromagnetic lower electrode, an oxidized-Al tunnel barrier, and a free ferromagnetic upper electrode, with the recognized figures of merit DR/R, RA, and breakdown voltage.
• Egelhoff (1997) supplies the oxygen-surfactant teaching: deliberately dosing oxygen during thin-film growth improves magnetic-film quality and magnetoresistance, acting as a surface surfactant.
• Ando (2002) and Shim (2003) supply the oxidation-method selection (natural vs. plasma vs. radical) and the known ROX technique, which the '841 specification itself calls "normally used."
• Nakashio (2000) supplies the CoFe(25%) composition selection that the patent claims yields high DR/R.

Motivation: The patent's own background frames the problem — "it would be highly desirable to form an Al₂Oₓ tunneling barrier layer that is flat and smooth and has an Al₂O₃ stoichiometry at its upper and lower interfaces … yielding both a high DR/R and breakdown voltage," and it notes that under-oxidation lowers Vb/DR/R while over-oxidation raises RA and lowers DR/R. Where the art identifies exactly this trade-off, a POSITA is motivated to seek more uniform oxidation. Egelhoff provides a known tool (an oxygen surfactant) for improving a magnetic-film interface, and applying it to the lower Al/electrode interface of an MTJ barrier is the natural, predictable application of a known technique in the same field of endeavor. Supplying oxygen to the bottom of the Al layer to complement the top-down plasma oxidation is an obvious way to reach the patent's stated goal of "symmetrical" oxidation.

Combination II — US 6,703,654 + Egelhoff + OSL application + ROX art (structural completeness)

This pairing supplies claim 1's specific structural stack almost verbatim:

• '654 discloses the NiCr seed layer, MnPt pinning layer, CoFe–Ru–CoFe SyAP pinned layer, an AlOₓ barrier made by plasma oxidation of a 7–10 Å Al film, a CoFe/NiFe free layer, and a Ta capping layer, all on a bottom conductor — and expressly ties these to low RA and high performance.
• Egelhoff + the OSL application (or the AAPA disclosure of the OSL in HT 02-032/HT 03-006) supply the one missing element: forming the Al on a pre-formed oxygen surfactant layer so that oxygen is supplied from below.
• Ando/Shim supply substituting ROX for the plasma oxidation of '654 to complete the bottom-up oxidation.

Motivation: Both references address the same problem (smooth, uniform, low-RA, high-DR/R AlOₓ barriers in MTJ devices). A POSITA optimizing the '654 bottom electrode/barrier for MRAM would look to known interface-improvement techniques. The OSL is disclosed as improving barrier stoichiometry and breakdown voltage; the gain is expected, not surprising, and the combination is a predictable arrangement of known layers. The '841 specification concedes the individual pieces: uniform oxidation from both surfaces, small Al grain size, and the OSL being a sub-monolayer of adsorbed oxygen.

Combination III — AAPA-based

Even setting aside the applications cited in the Prior Art table, the '841 specification admits that (a) ROX is conventional, (b) CoFe(25%) is a known high-DR/R choice, and (c) the OSL is described in incorporated related applications. The only purported point of novelty is applying the OSL beneath the Al in an MRAM (as opposed to a read-head or GMR) context and pairing it with ROX — a change of known use that, under KSR, is obvious absent unexpected results.

5. Why the differences do not confer patentability

1. "Having absorbed the oxygen thereof" / "uniformly small grain size" are result- or product-by-process limitations. They describe the consequence of depositing Al on an OSL, a process the art already teaches. A product-by-process/result limitation does not impart patentability to an otherwise obvious structure.
2. Routine optimization of ranges. The claimed thicknesses (Al 7–10 Å; CoFe(25%) 15–20 Å; Ru 7–8 Å; NiFe 25–50 Å) and process parameters (O₂ ~2×10⁻⁷ Torr, 0.02–0.04 sccm, 300 s; ROX 500–800 W) are optimization within ranges the art already explored. In re Aller/In re Boesch/In re Woodruff support treating such selections as obvious where the results are continuous and no criticality is shown.
3. CoFe composition. That CoFe(25%) gives higher DR/R than CoFe(10%) is admitted background and is corroborated by Nakashio; selection of the better-performing member of a small, known set is routine.
4. Oxygen dose. Egelhoff's ~5×10⁻⁹ Torr and the patent's ~2×10⁻⁷ Torr are the same order of magnitude and the same technique (deliberate low-pressure oxygen exposure during/after deposition).
5. Symmetry argument is the patent's own framing. The specification states that symmetric oxidation at both interfaces yields "both a high DR/R and breakdown voltage." That is the articulated motivation, supplied by the patent itself — which per KSR is sufficient rationale to combine.

6. Objective evidence (Graham factor 4)

• Unexpected results: The patent asserts improved DR/R and Vb, but Egelhoff already demonstrated that oxygen surfactant improves magnetoresistance (19.0%–24.8%, "largest ever reported" for such structures). The claimed benefit is an improvement in kind already taught, differing only in degree — not the sort of unexpected result that rebuts obviousness. No data are presented comparing OSL-present vs. OSL-absent barriers with statistical rigor; the DR/R/Vb table in the file relates to CoFe saturation magnetization, not to the barrier comparison.
• Teaching away: None identified. No reference discourages forming an oxygen layer under the Al barrier; Egelhoff affirmatively encourages oxygen dosing during growth.
• Long-felt need / commercial success / licensing: No evidence in the record attributes such objective indicia to the claim-1 structure; the patent expired 2024-04-08 and no litigation was located (per the earlier litigation section), so no nexus evidence is available.

7. Caveats and counter-arguments a defender would raise

1. Common ownership / pre-AIA § 103(c). US 2005/0170532 A1 and the incorporated HT 02-032/HT 03-006 material are commonly owned with '841 at the time of invention; if those references qualify only under § 102(e)/(f)/(g), § 103(c) would bar their use in a § 103 rejection. However, (a) that exclusion does not reach third-party art — Egelhoff, Ando, Shim, Nakashio, Parkin, Tehrani, Gallagher are all independent — and (b) the OSL subject matter is admitted into the '841 specification as AAPA, which remains available for § 103.
2. US 6,960,480 B1 is not prior art (filed after 2004-04-08); likewise HT 03-022 / 10/844,171 (filed 2004-05-12). The sputter-etched Ta element therefore rests on routine-prepractice evidence rather than on those specific documents — the weakest element of a paper rejection, and the element most likely to be argued on the merits.
3. The '654 (US 6,703,654) reference's status. It is Headway-assigned and may be commonly owned; a challenger would prefer third-party art (Parkin/Tehrani/Gallagher) for the structural elements to avoid § 103(c). The specific NiCr-seed/SyAP stack is nonetheless strongly supported by '654 and by the later Headway TaN-family description of conventional stacks ("MnO/MnPt … NiCr/Ru/Ta").
4. Discrepancy flag (carried from the earlier summary): the Google "Definitions" extract cites "Gallagher U.S. Pat. No. 5,640,373," while the patent body and citation list give 5,640,343. Both renderings appear in the source; I do not auto-reconcile them. This matters only insofar as the correct Gallagher reference must be cited accurately in any rejection.

8. Bottom line

Applying Graham/KSR to the art of record, claim 1 would have been obvious to a PHOSITA as of 2004-04-08. The strongest, cleanest combinations are:

• (A) Parkin '99 / Tehrani '99 / Gallagher '343 + Egelhoff '97 + Ando '02 / Shim '03 — supplies the MTJ-MRAM architecture, the oxygen-surfactant technique, and the oxidation-method selection, with the patent's own stated problem supplying the motivation to oxidize the Al from both surfaces.
• (B) US 6,703,654 + Egelhoff '97 (or the OSL disclosure/AAPA) + Ando/Shim — supplies the precise NiCr-seed / MnPt / CoFe–Ru–CoFe SyAP / AlOₓ / CoFe-NiFe stack and adds the sole missing element (Al deposited on an OSL), oxidized by the now-conventional ROX.

The dependent claims (2–13) add only conventional compositions, thicknesses, and material choices — routine optimization with no demonstrated criticality. The most defensible nonobviousness argument for the patent owner would rest on (i) the § 103(c) common-ownership exclusion of the OSL-specific Headway references, and (ii) the absence of a non-commonly-owned reference explicitly placing the OSL beneath the Al barrier — but the Egelhoff surfactant teaching plus the AAPA admission of the OSL close most of that gap. Unless secondary considerations with a proper nexus can be shown (none is in the record), claim 1 and its dependents are vulnerable to a § 103 challenge.

Caveat: this is a documentary analysis based on the prior art cited on the patent page and the patent's own admissions. It is not a validity opinion and should be confirmed against the full prosecution history (which could reveal the examiner's stated grounds of allowance) and complete prior-art databases.