Taiwan Semiconductor Manufacturing Company Limited v. Godo Kaisha IP Bridge 1

1. Case Identification

• Case #: IPR2017-00931
• Patent #: RE41,980
• Filed: February 17, 2017
• Petitioner(s): Taiwan Semiconductor Manufacturing Company Limited
• Patent Owner(s): Godo Kaisha IP Bridge 1
• Challenged Claims: 18, 19, 30-36, and 47-51

2. Patent Overview

• Title: Semiconductor Device and Method of Manufacturing the Same
• Brief Description: The ’980 patent describes semiconductor device structures aimed at preventing moisture absorption. The technology involves a dual-layer surface-protecting film over a metal wire layer, comprising a first dielectric film with a low dielectric constant (e.g., silicon oxide) to reduce parasitic capacitance, and a second, overlying dielectric film with a high moisture-blocking function (e.g., silicon nitride). The invention focuses on the structure of a bonding pad formed in an opening through this protective film, ensuring the pad and the moisture-blocking film completely cover the underlying low-dielectric film to seal it from moisture.

3. Grounds for Unpatentability

Ground 1: Anticipation over Ting - Claims 18, 19, 30-36, and 47-51 are anticipated by Ting under 35 U.S.C. §102.

• Prior Art Relied Upon: Ting (Patent 5,169,680).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Ting, which teaches the fabrication of double-metal VLSI integrated circuits, discloses every limitation of the challenged claims. Independent claim 18 requires a specific multi-layer structure, which Petitioner mapped to Ting's Figure 5. This mapping identifies Ting’s upper dielectric film (26) as the claimed "interlayer insulating film," its second conductive layer (36) and adhesive layer (35) as the "metal wire layer," and its dielectric layer (40) as the "surface protecting film." Crucially, this surface protecting film in Ting comprises a lower section of silicon dioxide (42) as the "first dielectric film" (low-k) and an upper section of silicon nitride (41) as the "second dielectric film" (moisture-blocking). Petitioner argued that Ting’s bonding pad (46), formed in an opening (45), and the silicon nitride film (41) completely cover the underlying silicon oxide film (42), thus meeting the final limitation of claim 18. Arguments for dependent claims followed this mapping, noting that Ting discloses the specific materials (silicon oxide, silicon nitride) and inherent properties (dielectric constant of ~3.9) recited.
  • Key Aspects: Petitioner contended that the inherent properties of the materials disclosed in Ting (silicon nitride being a better moisture barrier than silicon oxide) satisfy the functional limitations of the claims. Since the claims are for a device, Ting need only disclose the structure, and the function is an inherent result.

Ground 2: Obviousness over Ting in view of Jeng - Claims 18, 19, 30-36, and 47-51 are obvious over Ting in view of Jeng under 35 U.S.C. §103.

• Prior Art Relied Upon: Ting (Patent 5,169,680) and Jeng (Patent 5,527,737).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground was presented as an alternative, arguing that to the extent Ting is found not to explicitly disclose every element, Jeng provides the missing teachings. Specifically, if Ting’s disclosure of a single representative interconnect is deemed insufficient to teach "plural metal wires," Jeng rectifies this by teaching that VLSI circuits (the subject of Ting) inherently contain millions of such interconnecting lines. Further, if Ting’s disclosure of silicon dioxide is not considered to explicitly teach a "small dielectric constant," Jeng teaches the desirability of using low-k dielectrics (with constants <3.7) between metal lines to reduce parasitic capacitance and improve performance.
  • Motivation to Combine: A POSITA would combine Ting's fundamental VLSI structure with Jeng's teachings on interconnects for predictable improvements. Both references address improving integrated circuits. A POSITA would have been motivated to apply Jeng's specific teaching—using a low-k dielectric between closely spaced metal wires to reduce capacitance—to the structure in Ting to achieve the known benefits of reduced signal delay and crosstalk.
  • Expectation of Success: The combination involved applying known techniques to a known device architecture to achieve predictable results. A POSITA would have reasonably expected that incorporating a low-k dielectric as taught by Jeng into the inter-wire spaces of Ting’s device would successfully reduce parasitic capacitance, as this was a well-understood principle in the art.

4. Key Claim Construction Positions

• "interlayer insulating film": This term was central to the petition. In a prior, related IPR (IPR2016-01331), the Board construed this term as "an insulating film located between but not within other layers." Petitioner’s previous arguments in that IPR were rejected because its mapping of Ting’s structure did not satisfy this construction. In this petition, Petitioner advanced a new argument specifically tailored to the Board's construction. It argued that Ting’s upper dielectric film 26 alone, as distinct from the entire dual-layer film 25, meets the Board’s construction because it is an insulating film located between conductive layer 36 and dielectric film 27, but is not within either of those layers. This revised mapping was presented as the primary basis for the new petition.

5. Arguments Regarding Discretionary Denial

• Petitioner dedicated a significant portion of the petition to arguing why discretionary denial under §325(d) would be inappropriate, despite this being a follow-on petition to IPR2016-01331 which challenged the same patent with the same prior art. Petitioner argued that it could not have reasonably foreseen the Board’s narrow construction of "interlayer insulating film" at the time of the first filing. The new arguments in this petition were characterized as being responsive to the Board’s institution denial decision, and even addressed a suggestion the Board made in a footnote of that decision. Therefore, Petitioner contended this was not an improper "second bite at the apple" but a good-faith effort to address the specific legal and factual issues raised by the Board’s unanticipated ruling.

6. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 18, 19, 30-36, and 47-51 of the ’980 patent as unpatentable.