Method for improving measurement precision of ellipsometer

Abstract

The invention belongs to the technical field of optical and electronic devices and discloses a method for improving a measurement precision of an ellipsometer. The ellipsometer comprises a light source, a fixed polarizer, a rotary polarizer, a sample, an analyzer and a detector connected orderly, wherein the rotary polarizer and the analyzer rotate synchronously in a ratio of 1:2 at an angular velocity. The ellipsometer can acquire ellipsometry parameters by two self-consistent methods thereby acquiring various optical parameters of a test sample. Traditionally, ellipsometry parameters can be obtained by one of the two self-consistent methods, or ellipsometry parameters obtained by the two self-consistent methods are subjected to averaging. The method provided by the invention is a novel data processing method, realizes combination of the two self-consistent methods and can obviously improve a measurement precision.

Description

technical field [0001] The invention belongs to the technical field of optical and electronic devices, in particular to a method for improving the measurement accuracy of an ellipsometer. Background technique [0002] Spectroscopic ellipsometry is a spectroscopic measuring instrument, which is one of the most effective and reliable methods to obtain various information about the optical properties, optical constants and film thickness of functional materials. A variety of ellipsometry modes have been developed, such as extinction and photometry. In the photometric ellipsometer, the ellipsometer (RPAE) with rotating polarizer and analyzer at the same time does not need to measure the DC component of the signal, and can use two sets of equations to solve the ellipsometric parameters independently for self-consistent comparison , has superior performance and wider application range than rotating analyzer type ellipsometer (RAE) and rotating polarizer type ellipsometer (RPE). ...

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Problems solved by technology

But in fact, this approach is not necessarily correct, because although the two sets of equations themselves do not introduce any systematic error or random error, they are an intermediate step in obtaining ellipsometric parameters after all, and they introduce The systematic error of the system error, even the system error introduced by the component defect of the previous stage and the deviation of the instrument calibration before the measurement has a different response; in addition, a certain light intensity noise may also affect the ellipsometric parameter during the calculation process of the two sets of equations. The results have different degrees of magnification

Therefore, we cannot simply select one or two groups of methods to calculate the final result.

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