Patent ID: 9041903
Filing Date: 2015-05-26
Classification: G03F

Abstract:
1. A system comprising: a first detector located at a first Fourier plane and configured to detect a first portion of a first patterned light produced by a first section of a first mask; a first dynamic Fourier filter; a first controller configured to control the first dynamic Fourier filter based on the first portion of the first patterned light; a second detector configured to detect a second portion of the patterned light produced by the first section of the first mask after the second portion of the first patterned light transmits through the first dynamic Fourier filter; a first baffle located along a first optical path between the first mask and the first detector; a second baffle located along a second optical path between the first mask and the first dynamic Fourier filter, wherein the first baffle and the second baffle are configured to be adjusted to compensate for time delays in detection of the first portion of the first patterned light by the first detector and control of the first dynamic Fourier filter by the first controller; and a data analysis device configured to compare the second portion of the first patterned light with another patterned light.