Creep behavior of SiO2 films treated at elevated temperatures for SiC capacitive pressure sensors using nanoindentation technique and FE analysis

Abstract

As both the operating temperature and duration of SiC capacitive pressure sensors escalate, the creep characteristics of the SiO₂ thin film structure significantly impact the sensor's performance and reliability. This study aims to evaluate the creep characteristics of 2.2 μm-thick SiO₂ thin films subjected to different conditions. Firstly, we utilized nanoindentation technique and microscopic methods to perform creep analysis on SiO₂/SiC samples. Then, through curve fitting and numerical calculations, we determined the stress exponent of SiO₂ to range from 2.73 to 12.47 after high-temperature treatments, and derived the creep power-law model for the steady state. Finally, we imported the material parameters from tests and calculations into finite element (FE) analysis software to establish a nanoindentation creep model and simulate the testing process. The maximum relative error between the simulation and the experiment was 5.52%, validating the accuracy of the proposed model and the creep parameters obtained from the nanoindentation technique.