APPLICATION OF ALUMINUM FILMS AS TEMPERATURE SENSORS FOR THE COMPENSATION OF OUTPUT THERMAL SHIFT OF SILICON PIEZORESISTIVE PRESSURE SENSORS

Aluminum thin film resistors are proposed for use as temperature senso rs for the compensation of the thermal sensitivity and offset shift of pressure sensor output. An experimental investigation of Al films wit h different thicknesses and heat treatment was carried out in order to optimize the electric parameters of such temperature resistors. It wa s found that films with a thickness 1.2 mu m and thermal etched at 330 degrees C for 72 h have good long-time stability, a specific resistan ce of 2.85 mu Omega cm and a temperature coefficient of resistance of 4.33 x 10(-3)/degrees C. Th, obtained results indicate that Al resisto rs can be used in an electrical circuit for the passive temperature co mpensation of the thermal shift of pressure sensor output within a tem perature range of up to 125 degrees C. (C) 1998 Elsevier Science S.A. All rights reserved.