PTAB

IPR2016-00126

ASML Netherlands BV v. Energetiq Technology Inc

Log In
Key Events
Petition
petition Intelligence

1. Case Identification

2. Patent Overview

  • Title: Laser Sustained Plasma Light Source
  • Brief Description: The ’000 patent discloses a laser-driven light source that uses a laser to sustain a plasma within a pressurized, sealed chamber containing a gas. The technology is intended to provide a high-brightness light source, particularly for semiconductor manufacturing, while avoiding the wear and contamination associated with prior art systems that relied on electrodes to sustain the plasma.

3. Grounds for Unpatentability

Ground 1: Claims 7-10 are obvious over Sato in view of Gärtner.

  • Prior Art Relied Upon: Sato (Japanese Patent Publication No. JPS61-193358) and Gärtner (French Patent Publication No. FR2554302A1).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Sato taught a laser-sustained plasma light source that addressed the same problem as the ’000 patent: creating a long-service-life light source without electrodes. Sato disclosed a sealed, gas-filled "tube bulb" (chamber) made of sapphire, a laser to both ignite and sustain the plasma, and the production of ultraviolet light (>50 nm). However, Sato did not explicitly teach operating at pressures greater than 10 atmospheres. Gärtner was introduced to supply this missing element. Gärtner taught a similar laser-driven plasma light source for photolithography that operated at a working pressure of approximately 9.9 atmospheres and explicitly taught that increasing the pressure would increase the brightness of the light source. Gärtner also disclosed using a separate ignition source (e.g., a pulsed laser) when the sustaining laser's power was insufficient for ignition.
    • Motivation to Combine: Petitioner contended a person of ordinary skill in the art (POSITA) would combine these references to create a brighter, more efficient light source for photolithography, an application common to both references. A POSITA would have been motivated to apply Gärtner’s teaching of increasing pressure to increase brightness to Sato’s system. Sato’s use of a sapphire chamber would have been recognized as capable of withstanding the higher pressures taught by Gärtner. The combination would have been a predictable optimization of known elements to achieve a known goal (increased brightness).
    • Expectation of Success: A POSITA would have had a high expectation of success because the combination involved applying the well-understood principle that higher gas pressures in plasma lamps yield greater brightness. Modifying Sato’s system to operate at the higher pressures taught by Gärtner was presented as a matter of routine skill, yielding the expected result of an improved light source.

Ground 2: Claims 7-10 are obvious over Gärtner in view of Arp.

  • Prior Art Relied Upon: Gärtner (French Patent Publication No. FR2554302A1) and Arp (a 2004 journal article titled Feasibility of generating a useful laser-induced breakdown spectroscopy plasma on rocks at high pressure).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground used Gärtner as the primary reference, establishing the basic laser-sustained plasma light source in a pressurized chamber with an ignition source. Gärtner, however, disclosed using quartz windows. Petitioner asserted that the key claimed element of a "sapphire window" was not taught by Gärtner but was explicitly disclosed by Arp. Arp described a high-pressure (operating at 90 atm, rated for 204 atm) laser-induced plasma system that used thick sapphire windows precisely because of their ability to withstand high pressures and transmit a broad spectrum of light. Arp also taught a configuration where the laser energy enters and the plasma light exits through the same sapphire window.
    • Motivation to Combine: Petitioner argued that a POSITA seeking to optimize Gärtner's high-pressure light source would have been motivated to replace Gärtner’s quartz windows with the superior sapphire windows taught by Arp. The advantages of sapphire for high-pressure applications—including greater tensile strength, higher thermal conductivity, and broader transmission range—were widely known. As Gärtner taught increasing pressure to increase brightness, substituting a stronger window material like sapphire would be an obvious and logical improvement to allow for even higher pressures and greater reliability.
    • Expectation of Success: A POSITA would have reasonably expected success in this combination. It represented a simple substitution of a known, superior component (sapphire window) for a conventional one (quartz window) to enhance the performance of Gärtner's system in a predictable manner. The physical principles of transmitting light through a window are the same, and the known superior properties of sapphire provided a clear path to an improved, more robust device.

4. Key Claim Construction Positions

  • "Ignition source for ionizing a gas within the chamber": Petitioner argued that, based on the language of dependent claim 9 (which recites that the ignition source can comprise "the laser"), this term should be construed broadly to include embodiments where the same laser that sustains the plasma also serves as the ignition source. This construction was central to mapping Sato, which used a single laser oscillator for ignition, onto the claims.
  • "Light source": Petitioner proposed construing "light source" to mean a source of electromagnetic radiation across a broad spectrum, from extreme ultraviolet to far infrared. This construction was based on the specification's references to "ultraviolet light" and was intended to ensure that the light produced by the prior art references (e.g., UV light in Sato and Gärtner) fell within the scope of the claims.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 7-10 of the ’000 patent as unpatentable under 35 U.S.C. §103.