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

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°-90° rosette design. This rosette requires the application of only uniaxial stress for measurement of the three individual piezoresistive coefficients of silicon: π₁₁, π₁₂, and π₄₄. Of even greater potential import, this rosette yields inherently temperature compensated values of the coefficients π₄₄ and π_D=(π₁₁ -π₁₂). P-type off-axis rosettes have been characterized as a function of temperature, and values for the temperature dependencies of π₄₄ and π_D are reported. The coefficients π₄₄ in p-type silicon and π _D in n-type silicon are needed for an optimized stress sensor on (100) silicon