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Alignment system for exposure apparatus

  • US 4,962,318 A
  • Filed: 08/17/1989
  • Issued: 10/09/1990
  • Est. Priority Date: 08/19/1988
  • Status: Expired due to Term
First Claim
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1. An exposure apparatus for transferring a mask pattern to a wafer having a surface photoresist layer sensitive to a predetermined wavelength range, comprising:

  • first mark position detection means for illuminating said wafer with single wavelength or quasi monochromatic light as first light, detecting a first mark on said wafer illuminated by said first light and providing first position data concerning the position of said first mark according to the result of said first mark detection;

    second mark position detection means for illuminating said wafer with light having a wider wavelength distribution than said first light as second light, detecting a second mark on said wafer illuminated by said second light and providing second position data concerning the position of said second mark according to the result of said second mark detection; and

    position determination means for determining relative positions of said wafer and said mark according to both said first and second position data.

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