Patent ID: 6207960
Filing Date: 2001-03-27
Classification: B01J,C12Q,G01N,G02B

Abstract:
A system for detecting marked regions on a surface of a substrate, the system comprising:an excitation radiation source;a focusing system for focusing radiation from said excitation radiation source onto a selected region of said surface of said substrate, said focusing system including an objective lens having a ratio of scanning field diameter to focused spot diameter of greater than about 2000, and a numerical aperture greater than about 0.2;a reciprocating radiation direction system comprising a mirror selected from the group consisting of a galvanometric mirror, angularly oscillating mirror or a rotating polyhedral mirror for scanning said focused excitation radiation across said surface of said substrate at a rate of at least 20 image lines/second;a detector for detecting an emission from said surface of said substrate in response to said excitation radiation, wherein said objective lens receives said emission and transmits the emission to the detector; anda data acquisition system for recording an amount of said emission detected as a function of a position on said surface of said substrate from which said emission was emitted.