专利详情

专利名称	Method for detecting focus plane based on Hartmann wavefront detection principle
申请号	US201514857320	专利类型	US
公开（公告）号	US9400220(B2)	公开（授权）日	2016.07.26
申请（专利权）人	中国科学院光电技术研究所	发明（设计）人	Zhu Xianchang;Hu Song;Zhao Lixin
主分类号	G02B21/00	IPC主分类号	G02B21/00;G01J9/00;G03F1/00;G03F7/20
专利有效期	Method for detecting focus plane based on Hartmann wavefront detection principle 至Method for detecting focus plane based on Hartmann wavefront detection principle	法律状态
说明书摘要	The present disclosure relates to a method for detecting focus plane based on Hartmann wavefront detection principle, the function of which is to detect the position of a silicon wafer in a photolithograph machine in real time so as to accomplish adjustment of the leveling and focus of the silicon wafer. By utilizing microlens array to detect the wavefront carrying information about the position of the silicon wafer based on the Hartmann wavefront detection principle, the spherical wavefront is divided by the respective subunits of the microlens array and is imaged on the respective focus planes of the subunits. If the silicon wafer is located on the focal plane, the incident wavefront for the microlens array is a planar wavefront so that the diffraction light spots are on the focus of the respective subunits of the microlens array; and if the silicon wafer is defocused, the incident wavefront for the microlens array is a spherical wavefront so that the diffraction light spots are shifted on the focus plane of the microlens array. Based on Hartmann wavefront detection principle, the detection of the spherical wavefront may be implemented by the microlens array shifting the imaged light spots for the plane wavefront and the spherical wavefront, so as to accomplish the defocusing measurement for the silicon wafer. The system for detecting focus plane has a simple configuration, a higher accuracy and efficiency, so it is applied to measurement for detecting the focus plane in various types of photolithography machines in a high accuracy and in real time.