Research on the Thickness of Silicon Carbide Epitaxial Layer Based on the Geometrical Optics Propagation Model

Abstract

Silicon Carbide (SiC), as a third-generation semiconductor material, is widely used in electronic devices operating in extreme environments such as high temperature and high pressure. The thickness of the epitaxial layer greatly impacts the performance of SiC devices, making its precise measurement crucial. Infrared interferometry is a commonly used non-destructive measurement method, but existing studies often neglect the multi-beam interference effect. This paper proposes an improved method for measuring the epitaxial layer thickness by utilizing data from the 2025 National College Student Mathematical Modeling Competition B-topic, based on a single reflection and refraction model for calculating the epitaxial layer thickness. Data analysis confirmed the existence of multi-beam interference effects and led to the revision of the model, eliminating the impact of this effect on measurement accuracy. The corrected model improves measurement accuracy, with results significantly more accurate than traditional methods, proving the importance of multi-beam interference effects in thickness measurement. This method provides an effective solution for the precise measurement of SiC epitaxial layers and has significant practical application value.