A double-sided Fizeau interferometer detection device

Abstract

A double-sided Fizeau interferometer detection device, comprising a light source module, a first interferometer host, a second interferometer host, a first standard mirror, a second standard mirror, and a non-transparent plane to be measured; the first interferometer The host and the second interferometer host are both Fizeau interferometers. In the invention, the point light source is located on the focal plane of the collimating mirror but not on the focal point, so that the outgoing light transmitted by the collimating mirror and the optical axis of the interferometer have an included angle. After entering the interferometer on this side, it converges in the light-shielding area of ​​the diaphragm, which does not affect the reception of the interferometer on the side of the interferometer; or use an optical switch to make the first interferometer host and the second interferometer host work independently. The invention effectively improves the quality of the interferogram, and has the advantages of simple device structure, convenient operation and high measurement accuracy.

Description

technical field [0001] The invention relates to the field of interferometric measurement, in particular to a double-sided Fizeau interferometer detection device for measuring the surface topography of a non-transparent plane. Background technique [0002] Integrated circuits are the key technology to promote the continuous reform of the industry. With the continuous reduction of lithography feature size, the impact of silicon wafer surface topography on lithography performance is becoming more and more significant. As a special non-transparent plane optical element, the influence of the silicon wafer topography on the lithography focus depth can be calculated by detecting the surface flatness, shape and other parameters of the silicon wafer, and the surface stress of the silicon wafer can be calculated at the same time. The detection of in-plane distortion of lithography patterns reduces overlay errors caused by other processes other than lithography. [0003] Therefore, in...

AI Technical Summary

Problems solved by technology

However, according to the above-mentioned double-sided Fizeau interferometer spectroscopic device, when calibrating the central cavity of the first standard mirror and the second standard mirror, a large amount of outgoing light from the interferometer enters the opposite side interferometer, which affects the detection of the interference signal. The measurement of the surface topography of the measured surface brings errors

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