Light spot layout structure, surface shape measurement method and exposure field control value calculation method

Abstract

The invention discloses a light spot layout structure, a surface shape measurement method and an exposure field control value calculation method. The light spot layout structure comprises a plurality of measurement light spots, wherein the plurality of measurement light spots at least form a group of orthogonal straight lines, the measurement light spots on the orthogonal straight lines are scattered to outside from the center, at least four measurement light spots are arranged on each straight line, and the measurement light spots are used for measuring a surface shape of a plane. With the technical scheme provided by the invention, the light spot layout structure at least comprising one group of orthogonal straight lines scattered to outside from the center is employed, a plurality of light spot reading numbers can be measured in real time, the surface shape of a substrate is obtained by planar fitting for focusing, leveling and exposure in real time, the light spot reading numbers can also be effectively read by scanning movement of a workpiece table and are converted to original surface shape data of the substrate, and the original surface shape data is processed to obtain an exposure field control value of the workpiece table for performing focusing, leveling and exposure.

Description

technical field [0001] The invention relates to a light spot layout structure, a surface shape measurement method and a calculation method for a control value of an exposure field of view, which are applied in the field of photolithography technology. Background technique [0002] A projection lithography machine is a device that projects the pattern on the mask onto the surface of a silicon wafer through a projection objective lens. During the exposure process of the lithography machine, if the silicon wafer is defocused or tilted relative to the focal plane of the objective lens so that some areas in the exposure field of view are outside the effective focal depth, it will seriously affect the quality of lithography. Therefore, it is necessary to use focus adjustment The flat system is precisely controlled. There are two commonly used focusing and leveling methods, one is to measure the height and inclination of the workpiece table in real time by using a specific layout ...

AI Technical Summary

Problems solved by technology

This processing method is not suitable for situations where the depth of focus is small and the shape of the edge surface is quite different from the shape of the interior surface, such as the case where the edge of the substrate is warped. This method will often cause defocus at the edge of the substrate and cannot be used.

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