Total dose radiation effects of pressure sensors fabricated on Unibond－SOI materials
摘要
Piezoresistive pressure sensors with a twin-island structure were suc cessfully fabricated using high quality Unibond-SOI (On Insulator) materials. Since the piezoresistors were structured by the single crystalline silicon overlayer of the SOI wafer and were totally isolated by the buried SiO2, the sensors are radiation-hard. The sensitivity and the linearity of the pressure sensors keep their original values after being irradiated by 60Co γ-rays up to 2.3 × 104 Gy (H2O). However, the offset voltage of the sensor has a slight drift, increasing with the radiation dose. The absolute walue of the offset voltage deviation depends on the pressure sensor itself. For comparison, corresponding polysilicon pressure sensors were fabricated using the similar process and irradiated at the same condition.