Comparison spectrum system and measurement method for realizing high depth-to-width ratio micro-groove depth measurement

Abstract

The invention discloses a comparison spectrum system and a measurement method for realizing high depth-to-width ratio micro-groove depth measurement. The comparison spectrum system comprises a light source module (100), a beam splitter (200), a sample measurement module (300), a reference substance measurement module (400) and a spectrum acquisition module (500), wherein the light source module (100) outputs an illumination light beam with a set diameter, and the beam splitter (200) splits the illumination light beam into two light beams which respectively enter the sample measurement module (300) and the reference substance measurement module (400); the sample measurement module (300) and the reference substance measurement module (400) return a sample spectrum and a reference substance spectrum respectively; and the spectrum acquisition module is used for collecting spectrums of the sample and the reference substance, transmitting the spectrums to the computer for calculating a comparison spectrum, and analyzing the depth value of the groove with the high depth-to-width ratio by utilizing a spectral Fourier analysis method and a spectral fitting method. According to the invention, the influence of sample chromatic aberration on the depth measurement range and the analysis accuracy is avoided; and the understanding calculation efficiency and precision are improved.

Description

technical field [0001] The invention relates to the technical field of non-destructive measurement of depth values ​​of high aspect ratio microstructures, in particular to a system and method for contrast spectrum measurement of the depth of microgrooves with high aspect ratio. Background technique [0002] With the continuous improvement of MEMS process technology and application level, the high aspect ratio micro-trench structure can significantly improve the charge storage capacity and increase the interdigital capacitance and sensor sensitivity due to its narrow and vertical air gap and large specific surface area. , Therefore, it has a wide range of applications in the fields of comb-shaped microelectrode arrays, supercapacitors, acceleration sensors, gyroscopes, gratings, and micro-nano resonators. In order to improve the quality of MEMS trench manufacturing and ensure device yield, it is necessary to measure and analyze its three-dimensional characteristic dimensions ...

AI Technical Summary

Problems solved by technology

However, this method is limited by the frequency resolution of Fourier analysis, resulting in a large error in the depth value obtained by analysis.

At the same time, the chromatic aberration of the sample and the optical system also affects the depth measurement range of the spectroscopic analysis method

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