Silicon carbide is considered as a more suitable material for piezoresistive pressure sensors in a high-temperature environment due to its excellent characteristics. In this paper, fundamental research on the structural design of SiC piezoresistive pressure sensors was carried out through the finite element method (FEM) to accurately estimate the optimal output characteristics. The effects of various boundary conditions on the deflection and stress distribution of SiC circular diaphragm were analyzed to determine the difference between the edge-clamped structure in traditional theory and the bottom-fixed structure in actual pressure sensors. Furthermore, on the basis of appropriate boundary conditions, the design considerations for SiC piezoresistors were discussed in detail to study the influence of different parameters on the sensitivity and nonlinearity of pressure sensors, including the shape, placement, dimension, and connection methods with metal lines. Both simulation results and theoretical analysis indicated that the suitable piezoresistor design can achieve larger resistance variations in both longitudinal and transverse piezoresistors and less difference between them, which is beneficial to the performance optimization of SiC piezoresistive pressure sensors.

碳化硅由于其优异的特性，被认为是高温环境下压阻式压力传感器的更合适材料。本文通过有限元方法（FEM）对SiC压阻式压力传感器的结构设计进行了基础研究，以准确估算最佳输出特性。分析了各种边界条件对SiC圆形膜片挠曲和应力分布的影响，以确定传统理论中的边缘固定结构与实际压力传感器中的底部固定结构之间的差异。此外，在适当的边界条件的基础上，详细讨论了SiC压敏电阻的设计注意事项，以研究不同参数对压力传感器的灵敏度和非线性的影响，包括形状，位置，尺寸以及与金属线的连接方法。仿真结果和理论分析均表明，合适的压敏电阻设计可以在纵向和横向压敏电阻中实现较大的电阻变化，并且两者之间的差异较小，这有利于SiC压阻式压力传感器的性能优化。