ULTRA-STABLE, HIGH-TEMPERATURE PRESSURE SENSORS USING SILICON FUSION BONDING

Piezoresistive silicon-based pressure sensors have been fabricated which are capable of high-precision operation at temperatures as high as 250°C. These devices are fabricated by a unique silicon fusion bonding process in which resistors from one wafer are bonded to the oxidized surface of a second wafer. The intermediate oxide layer electrically isolates the resistors from each other, thereby providing the high-temperature capability. Chip performance is excellent, especially linearity and the stability of offset voltage and pressure sensitivity. © 1990.