Method for detecting focus plane based on Hartmann

专利名称：Method for detecting focus plane based on

Hartmann wavefront detection principle

发明人：Xianchang Zhu,Song Hu,Lixin Zhao申请号：US14857320申请日：20150917公开号：US09400220B2公开日：20160726

专利附图：

摘要：The present disclosure relates to a method for detecting focus plane based onHartmann wavefront detection principle, the function of which is to detect the position ofa 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 thewavefront carrying information about the position of the silicon wafer based on theHartmann wavefront detection principle, the spherical wavefront is divided by therespective subunits of the microlens array and is imaged on the respective focus planesof the subunits. If the silicon wafer is located on the focal plane, the incident wavefrontfor the microlens array is a planar wavefront so that the diffraction light spots are on thefocus 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 thatthe diffraction light spots are shifted on the focus plane of the microlens array. Based onHartmann wavefront detection principle, the detection of the spherical wavefront may beimplemented by the microlens array shifting the imaged light spots for the planewavefront and the spherical wavefront, so as to accomplish the defocusing measurementfor the silicon wafer. The system for detecting focus plane has a simple configuration, ahigher accuracy and efficiency, so it is applied to measurement for detecting the focusplane in various types of photolithography machines in a high accuracy and in real time.

申请人：The Institute of Optics and Electronics, The Chinese Academy of Sciences

地址：Chengdu, Sichuan CN

国籍：CN

代理机构：Merchant & Gould P.C.

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