PTAB

IPR2016-01512

Samsung Electronics Co Ltd v. Flamm Daniel

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method for Etching a Substrate
  • Brief Description: The ’264 patent describes methods for etching a substrate, such as a semiconductor wafer, during device manufacturing. The invention focuses on precisely controlling the temperature of the substrate and substrate holder through multiple processing steps, including changing the substrate temperature from a first selected temperature to a second selected temperature within a preselected time interval.

3. Grounds for Unpatentability

Ground 1: Obviousness over Kadomura and Matsumura - Claims 27, 32, 37, and 40 are obvious over Kadomura in view of Matsumura.

  • Prior Art Relied Upon: Kadomura (Patent 6,063,710) and Matsumura (Patent 5,151,871).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Kadomura taught a multi-step dry etching method where a semiconductor specimen is processed at a first temperature and then a second, different temperature. For example, Kadomura disclosed a main etching step at -30°C followed by an overetching step at 50°C. While Kadomura disclosed changing the temperature and using a temperature sensor for the specimen, Petitioner contended it did not explicitly teach performing this change within a "preselected time interval" as required by independent claims 27 and 37. To supply this limitation, Petitioner pointed to Matsumura, which disclosed a method for heat-processing semiconductor devices according to a pre-programmed "recipe." Matsumura’s recipes explicitly defined temperature changes over preselected time intervals (e.g., 20°C to 90°C within 60 seconds) based on feedback from a temperature detecting signal to accurately control the device's thermal history.
    • Motivation to Combine: Petitioner asserted that a person of ordinary skill in the art (POSITA) would combine the teachings of these references to improve the etching process. A POSITA would be motivated to implement Matsumura's precise, recipe-based temperature control into Kadomura's multi-step etching process to achieve better process control, repeatability, and flexibility. This combination would allow for predictable and controlled temperature ramps between different etching steps, a known goal in semiconductor manufacturing.
    • Expectation of Success: A POSITA would have a high expectation of success because both references related to temperature control in semiconductor processing, used conventional components like heaters and sensors, and applying a pre-programmed time-temperature profile (Matsumura) to a multi-temperature etching process (Kadomura) was a straightforward application of known control principles.

Ground 2: Obviousness over Kadomura, Matsumura, and Narita - Claims 31 and 50 are obvious over Kadomura and Matsumura in view of Narita.

  • Prior Art Relied Upon: Kadomura (Patent 6,063,710), Matsumura (Patent 5,151,871), and Narita (Patent 4,913,790).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground built upon the Kadomura and Matsumura combination to address dependent claims 31 and 50, which required changing the substrate temperature by "transferring energy using at least radiation." Petitioner argued that while the primary combination disclosed using a "heater" to change the temperature, it did not specify the type of heat transfer. Narita cured this deficiency by explicitly teaching a method for accurately controlling workpiece temperature using radiative heating, such as from an "infrared ray lamp, halogen lamp or a normal heater," and stated its invention was applicable to plasma etching.
    • Motivation to Combine: A POSITA seeking to implement the combined Kadomura-Matsumura system would have been motivated to look to references like Narita for known heating methods. Incorporating Narita's radiative heating would provide the system with alternative and flexible heat source options. Petitioner argued this was an obvious design choice, allowing a process designer to select from various well-known heating technologies to best suit a particular application.
    • Expectation of Success: The combination was asserted to be predictable. Modifying the heater in the Kadomura system to be a radiative heater as taught by Narita was a simple substitution of one known type of heater for another within a well-understood technological field.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including:

    • Ground 3: Claims 27, 34, 37, 41, and 44 are obvious over Kadomura and Matsumura in view of Wang I (Patent 5,219,485). This combination used Wang I’s teaching that increasing substrate temperature increases the etch rate of silicides to motivate performing one of Kadomura's etching steps at a temperature above room temperature.
    • Ground 4: Claims 47 and 48 are obvious over Kadomura, Matsumura, and Wang I in view of Wang II (European Patent Application No. 87311193.4). This ground added Wang II to teach that a film treatment step could comprise chemical vapor deposition (CVD), a well-known technique for depositing SiO₂ films.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 27, 31-32, 34, 37, 40-41, 44, 47-48, and 50 of the ’264 patent as unpatentable.