×

Method and apparatus for detecting aberrations in an optical system

  • US 6,788,400 B2
  • Filed: 12/04/2001
  • Issued: 09/07/2004
  • Est. Priority Date: 12/06/2000
  • Status: Expired due to Term
First Claim
Patent Images

1. A method of detecting aberrations associated with an optical system utilized in a lithographic projection apparatus comprising:

  • a radiation system for supplying a projection beam of radiation;

    a support structure for supporting patterning means, the patterning means serving to pattern the projection beam according to a desired pattern;

    a substrate table for holding a substrate; and

    a projection system for projecting the patterned beam onto a target portion of the substrate, said optical system comprising at least one of the radiation system and projection system, said method comprising the steps of;

    providing said desired pattern to comprise a monitor having a plurality of sub resolution features, where the plurality of sub-resolution features are arranged so as to form a predetermined test pattern when projected on the substrate;

    projecting the monitor onto the substrate using the projection system, and;

    analyzing the position of said predetermined test pattern and the position of the plurality of sub-resolution features in the monitor so as to determine if there is an aberration, wherein none of said plurality of sub-resolution features are individually imaged on said substrate.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×