Device and method for detecting optical surface profile

Abstract

The invention discloses a device and a method for detecting an optical surface profile. Light which is emitted by a laser is reflected by a beam splitter, a collimation optical system, a reflective mirror and a reference surface to form reference light; the reference plane is interfered with a plane to be detected; interference light returns through an optical path, passes through the beam splitter and is collected to a charge coupled device (CCD) detector by a collecting mirror set to be received; a phase shifter is used for generating phase shift; a rotary table is used for controlling the rotation of the reference plane; a translation table is used for controlling the movement of the plane to be detected; the plane to be detected is moved by the translation table so as to measure different sub apertures on the plane to be detected; the rotary table is used for controlling the rotation of the reference plane; and surface profile information of two planes is solved by using two planes in the splicing process of the sub-apertures on the basis of the original three-plane measurement algorithm. By the method and the device, detection accuracy is improved, mirrors are not needed to be detected in the detection process, the absolute measurement can be finished by two planes, and the repeatability and the reproducibility of the detection are improved.

Description

technical field [0001] The invention belongs to the technical field of optical detection, and relates to an optical surface shape detection device and a detection method. Background technique [0002] High-precision interferometric surface measurements are becoming more and more important, not only in the traditional field of optical manufacturing, but also in new fields such as the surface of optical discs or the surface of semiconductor crystals. There are more and more requirements for the detection accuracy of pv value in the sub-nanometer range. With the rapid development of modern industry and science and technology, especially the continuous improvement of modern large-scale integrated circuit technology, the requirements for system precision are increasing day by day. In lithography systems, shorter and shorter wavelengths require us to use higher precision lithography objectives. Before that, we need higher precision detection technology to meet the needs of proce...

AI Technical Summary

Problems solved by technology

Absolute measurement can remove the error of the reference plane during the measurement process. The usual absolute measurement requires three-plane mutual inspection, and the mirror needs to be replaced during the detection process. The process of replacing the mirror will introduce repeatability errors and reproducibility during the measurement process. error

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