Prediction of Temperature‐Dependent Stress in 4H‐SiC Using In Situ Nondestructive Raman Spectroscopy Characterization

Abstract 4H‐SiC is widely used in power electronics owing to its superior physical properties. However, temperature‐induced stresses compromise the reliability of 4H‐SiC power devices in high‐temperature applications, warranting precise, and nondestructive stress characterization responsive to temperature variations. Herein, a temperature‐dependent predictive model is proposed for analyzing the Raman shift–stress in 4H‐SiC. The 4H‐SiC epitaxial samples prepared via chemical vapor deposition are characterized using in situ variable‐temperature Raman spectroscopy, resulting in a temperature correction factor of approximately −0.021 cm−1 K−1, which is integrated into the conventional Raman shift–stress relationship to assess stress variations induced by temperature variations. The elastic modulus tensor of 4H‐SiC at various temperatures determined using molecular dynamics simulations indicates a linear reduction in modulus with increasing temperature. This variable temperature modulus is incorporated into the Raman shift–stress relationship. Furthermore, a finite element method is used for model simplification to perform stress calculations in three axial directions. The experimental results confirm the consistency between calculated and experimental values with a 10% error range under the uniaxial stress condition. The study findings provide valuable insights into assessing stress evolution in 4H‐SiC under temperature variations based on Raman spectroscopy, thereby advancing the application of spectroscopic techniques in material stress detection.