Semiconductor pressure sensor

Abstract

Abstract PURPOSE:To suppress a mutual thermal interference between a piezoresistance element and a temperature-sensing element thanks to an action by a low thermal-conductivity part to reduce the thermal interference by a method wherein the low thermal- conductivity part is installed between a diaphragm part and the temperature-sensing element. CONSTITUTION:A groove 9 is formed at the rear surface of an Si substrate 1 between a diaphragm part 2 and a third-layer part 8 where a temperature-sensing element 7 is formed. Because the groove 9 functions as a low thermal-conductivity part, a thermal influence by the temperature-sensing element 7 as a heat source installed on the thick-layer part 8 to be remote from the groove 9 becomes small with reference to piezoresistance elements 3-6 which are installed on the surface of the diaphragm part 2 acting as a distortion-causing part. In addition, the groove functions in such a way that an influence by the heat generated at the distortion-causing part or by the distortion due to the impressed pressure is hardly transmitted to the temperature- sensing element 7 formed at the thick-layer part 7. Thanks to an action by the groove 9 to reduce a thermal interference a change in temperature at a zero point of a bridge constituted by the piezoresistance elements 3-6 does not cause any hysteresis; a characteristic corresponding to a change in the external temperature is obtained.

Inventors

• 👤 Satoru Ohata
• 👤 覚 大畠

Bibliographic Details