Finnegan, Henderson, Farabow, Garrett & Dunner, L.L.P.
Multi-lens array of a wavefront sensor for reducing optical interference and method thereof
A wavefront sensor is provided to determine characteristics of an incoming distorted energy beam. The sensor includes a plurality of multi-lens array and a beam detector, such as a CCD camera. The multi-lens array focuses the energy beam to a multiple focal spots forming a diffraction pattern on the CCD camera. The invention teaches a method to eliminate or substantially reduce a cross talk or interference in measuring the intensity of the focal spots. The beam detector or CCD detects the resulted focal spots and determines the characteristics of the incoming energy beam. The method and wavefront sensor according to this invention can be used in combination with an exposure apparatus in a semiconductor wafer manufacturing process.
Nikon Corporation
G G
G03F G01J
inventional inventional
Chia-Yu Takeshi
Ai Asami