中圖分類號：TN304.2 文獻標志碼：A DOI: 10.16157/j.issn.0258-7998.267931
中文引用格式： 彭沖沖，張樂玉，柳楊浩，等. 基于光學干涉模型的碳化硅外延層厚度測量研究[J]. 電子技術(shù)應用，2026，52(6)：58-63.
英文引用格式： Peng Chongchong，Zhang Leyu，Liu Yanghao，et al. Research on the measurement of silicon carbide epitaxial layer thickness based on optical interference model[J]. Application of Electronic Technique，2026，52(6)：58-63.

Research on the measurement of silicon carbide epitaxial layer thickness based on optical interference model

Abstract： The accurate measurement of silicon carbide epilayer thickness is the key to the fabrication of semiconductor devices. This paper conducts research based on the measured data of Problem B in the 2025 National Undergraduate Mathematical Modeling Competition. Firstly, Savitzky-Golay smoothing filtering, wavelength window function and Huber Loss robust loss function are used to preprocess high-frequency noise, baseline drift and outliers in the original data. Secondly, a dual-beam interference model is constructed. Combined with the Sellmeier dispersion equation, the quantitative relationship between thickness and related parameters is derived. High-precision inversion is achieved through initial estimation by Fast Fourier Transform (FFT), iterative optimization by nonlinear least squares and inverse variance weighted average, and its effectiveness is verified by back-injection test. Thirdly, a multi-beam interference model is established. Thickness inversion is realized based on the transfer matrix method, and a method of oscillation component extraction and baseline recovery correction is proposed to reduce interference.

Key words : silicon carbide epilayer；thickness measurement；optical interference model；Sellmeier dispersion equation；iterative inversion algorithm