Off-axis sensor rosettes for measurement of the piezoresistive coefficients of silicon

Abstract

Experimental calibration results for the piezoresistive coefficients of silicon as a function of temperatures are presented. Measurements have been performed using a test chip incorporating a new off-axis 0-45 degrees -90 degrees rosette design. This rosette requires the application of only uniaxial stress for measurement of the three individual piezoresistive coefficients of silicon: pi /sub 11/, pi /sub 12/, and pi /sub 44/. Of even greater potential import, this rosette yields inherently temperature compensated values of the coefficients pi /sub 44/ and pi /sub D/=( pi /sub 11/- pi /sub 12/). P-type off-axis rosettes have been characterized as a function of temperature, and values for the temperature dependencies of pi /sub 44/ and pi /sub D/ are reported. The coefficients pi /sub 44/ in p-type silicon and pi /sub D/ in n-type silicon are needed for an optimized stress sensor on