A high temperature pressure sensor with β-SiC piezoresistors on SOI substrates

Abstract

This paper reports about the first piezoresistive pressure sensor for high operating temperatures using single crystalline, n-type /spl beta/-SiC piezoresistors on Silicon On Insulator (SOI) substrates. The new Silicon Carbide On Insulator (SiCOI) layer structure prevents a leakage current flow through the substrate at high temperatures up to 723 K. The sensor was tested in the temperature range between room temperature and 573 K. The sensitivity of the device at room temperature is approximately 20.2 /spl mu/V/VkPa. This corresponds to a longitudinal gauge factor of -32 in the [100]-direction. The Temperature Coefficient of Sensitivity (TCS) is -0.16 %K/sup -1/ at 573 K.