Optical surface shape detection device and method

Abstract

The invention discloses an optical surface shape detection device and an optical surface shape detection method. The emitted light of a laser of the device is processed by a beam splitter and a collimation optical unit to generate illumination light; planes to be detected on a first clamping frame and a second clamping frame generate interference lights which return through a light path and then are collected to a CCD detector by the beam splitter through a convergence optical unit; a phase shifter is used for generating phase shift; and an angle measurement unit is used for measuring angle difference between the planes to be detected on the first and second clamping frames. The method comprises the following steps: putting the first and second planes to be detected on the second and first clamping frames respectively, and performing interferometry on the optical path difference between the first and second planes to be detected; rotating the first plane to be detected for a certain specific angle relative to the initial position and measuring the optical path difference between the first and second planes to be detected; rotating the first plane to be detected for 180 degrees, putting a third plane to be detected on the first clamping frame, and measuring the optical path difference between the first and third planes to be detected; and putting the second plane to be detected on the second clamping frame and measuring the optical path difference between the second and third planes to be detected.

Description

technical field [0001] The invention belongs to the technical field of optical surface shape detection, and relates to a seven-step absolute measurement optical detection method and a realization device. 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, ever-shorter wavelength requirements require us to use higher precision lithography objectives. Before that, we need higher precision detection...

AI Technical Summary

Problems solved by technology

[0014] The traditional technology mainly rotates the first plane to be measured

The angular rotation error during the rotation of the first plane to be measured will have a greater impact

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