Bilateral Fizeau interferometer detection device

Abstract

A bilateral Fizeau interferometer detection device comprises a light source module, a first interferometer host, a second interferometer host, a first standard lens, a second standard lens and a detected non-transparent plane. The first interferometer host and the second interferometer host are both Fizeau interferometers. The point light source is located on the focal plane of the collimating mirror but not on the focal point, so that an included angle is formed between the emergent light transmitted by the collimating mirror and the optical axis of the interferometer, and through cooperation with the diaphragm, the emergent light of the interferometer at the opposite side enters the interferometer at the local side and then converges at the shading area of the diaphragm, and the receiving of an interferogram of the interferometer at the local side is not influenced; or the optical switch is used for enabling the first interferometer host and the second interferometer host to work independently. The device effectively improves the quality of an interference pattern, and has the advantages of simple structure, convenience in operation and high measurement precision.

Description

technical field [0001] The invention relates to the field of interferometry, 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 influence of silicon wafer surface topography on lithography performance is becoming more and more significant. As a special non-transparent planar optical element, through the detection of the surface flatness, shape and other parameters of the silicon wafer, the influence of the silicon wafer shape on the lithography focus depth can be calculated, and the surface stress of the silicon wafer can be calculated to realize the Detection of in-plane distortion of lithographic patterns reduces overlay errors caused by other processes other than lithography. [0003] Therefore, in order ...

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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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