Taiwan Semiconductor Mfg Co Ltd v. Marlin Semiconductor Ltd

1. Case Identification

• Case #: IPR2025-00864
• Patent #: 9,184,292
• Filed: April 17, 2025
• Petitioner(s): Taiwan Semiconductor Manufacturing Company, Ltd., and Apple, Inc.
• Patent Owner(s): Marlin Semiconductor Limited
• Challenged Claims: 1-20

2. Patent Overview

• Title: Semiconductor Fin Structure and Method of Fabricating Same
• Brief Description: The ’292 patent relates to a semiconductor structure for forming FinFETs. The disclosed technology involves a substrate with a plurality of "odd fins" and a plurality of "even fins," where the even fins are located between the odd fins and are different from the odd fins in at least one of width, material, or height.

3. Grounds for Unpatentability

Ground 1: Claims 1, 3-9, 11-15, and 17-20 are obvious over Basker and Hill

• Prior Art Relied Upon: Basker (Application # 2011/0108920) and Hill (Patent 7,297,581).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Basker taught a FinFET structure for integrated circuits (ICs) using silicon (Si) fins for nFinFETs and silicon-germanium (SiGe) fins for pFinFETs to improve performance. The SiGe fins were formed by incorporating epitaxially-deposited material. Hill taught a method for fabricating tightly spaced FinFETs for high-density SRAM cells using an angled implantation process that results in an alternating n-type and p-type (n-p-n-p) fin pattern. The combination of Basker's different materials for n-type and p-type fins with Hill's alternating pattern for a high-density SRAM allegedly taught all limitations of the independent claims, including odd/first fins of one material (Si) and even/second fins of a different material (epitaxial SiGe).
  • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine Basker's teachings on performance-enhancing fin materials with Hill's method for creating high-density SRAM. The motivation was to produce a high-density, high-performance SRAM device, which was a well-known application for FinFETs. Hill’s reduction in SRAM cell size and Basker’s performance improvements were complementary and sought-after goals.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success as both references operate in the same field of FinFET fabrication for ICs. The combination involved applying known materials (Si/SiGe fins) to a known device structure (SRAM) using a known fabrication pattern (alternating n-p) to achieve the predictable result of a compact, high-performance memory cell.

Ground 2: Claims 2, 10, and 16 are obvious over Basker, Hill, and Yu

• Prior Art Relied Upon: Basker (Application # 2011/0108920), Hill (Patent 7,297,581), and Yu (Application # 2008/0230852).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground added Yu to the Basker and Hill combination to teach the limitation that the even/second fins are further different from the odd/first fins in height. Petitioner asserted that Yu explicitly taught forming FinFETs with customized, different fin heights on the same chip to achieve customized performance by modifying the channel width.
  • Motivation to Combine: A POSITA would have been motivated to incorporate Yu’s teachings to optimize the performance of the SRAM cell from the Basker-Hill combination. SRAM performance, specifically the static noise margin, was known to depend on the pull-up ratio (PR) of the transistors, which is a function of their dimensions. Adjusting fin height, as taught by Yu, was a known method to tune the effective channel width and thereby optimize the PR and overall SRAM performance.
  • Expectation of Success: Yu taught that customizing fin height was a "result-effective variable" for tuning FinFET performance. A POSITA would have reasonably expected to successfully apply this known optimization technique to the SRAM of Basker-Hill to achieve a predictable improvement in device function.

Ground 3A/3B: Claims 1, 5, 7-9, 13, 15, and 19 are anticipated by or obvious over Inaba

• Prior Art Relied Upon: Inaba (Application # 2008/0308848).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground was argued under the Patent Owner’s alleged litigation claim construction. Petitioner argued that Inaba, which disclosed a FinFET-based SRAM cell, anticipated or rendered obvious the challenged claims. Inaba's layout showed groups of nFinFETs and pFinFETs. Petitioner mapped the groups of nFinFET fins (e.g., fins 5a, 5b, 5x) as the "plurality of odd fins" and the group of pFinFET fins (e.g., fins 2A, 3) as the "plurality of even fins." Inaba's pFinFET fins were located between the nFinFET groups and were explicitly disclosed as having a greater width than the nFinFET fins, thus meeting the limitation of being different in at least width.
  • Key Aspects: This argument relied on interpreting "plurality of odd fins" not as single, alternating fins but as a group of two or more similar fins, which Petitioner contended was consistent with the Patent Owner’s infringement theory in parallel litigation.

• Additional Grounds: Petitioner asserted additional obviousness challenges based on combinations including Inaba and Basker; Inaba and Yu; Liaw (Patent 8,942,030) and Basker; and Liaw, Basker, and Yu, relying on similar technology substitution and design optimization rationales.

4. Key Claim Construction Positions

• Petitioner argued that the grounds for unpatentability were established under two different interpretations of the claim terms "a plurality of odd [or first] fins" and "a plurality of even [or second] fins."
• Plain and Ordinary Meaning: Consistent with the ’292 patent’s specification and figures, this interpretation requires a structure with a single odd fin alternating with a single even fin (e.g., an odd-even-odd-even pattern). Grounds 1 and 2 were argued to invalidate the claims under this construction.
• Patent Owner's Litigation Position: Petitioner asserted that in parallel litigation, the Patent Owner advanced a broader construction where "a plurality of odd fins" could be a group of similar fins (e.g., two NMOS fins) and "a plurality of even fins" could be an adjacent group of different fins (e.g., two PMOS fins). Grounds 3 through 7 were argued to invalidate the claims under this alternative construction.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §314(a) would be inappropriate. The key reasons asserted were:
  • The petition was filed expeditiously, just 23 days after a parallel ITC investigation was instituted, and the ITC had not yet set a schedule or issued substantive orders.
  • The merits of the petition are strong, addressing all claims under two different claim construction theories.
  • The IPR presents a more efficient path to finality, as the ITC lacks the authority to invalidate the challenged claims.

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-20 of the ’292 patent as unpatentable.