A 400 °C silicon Hall sensor

Abstract

The maximum operating temperature of conventional silicon sensors is limited to about 200 °C, due to excessive thermal generation of carriers at higher temperatures. The minority-carrier exclusion effect can be exploited to reduce the number of thermally generated carriers, ultimately maintaining extrinsic carrier concentrations at intrinsic temperatures. Based on this effect, a silicon magnetic-field sensor with a maximum operating temperature of about 400 °C is presented. The sensitivity has been improved by about 500% with respect to a previously reported version, and now measures about 60 V (A T)-1 at room temperature. Additionally, the theoretical support of the exclusion effect has been improved with a more accurate analytical model.