Silicon Diffused-Element Piezoresistive Diaphragms

Abstract

The properties of a pressure transducer consisting of a single-crystal silicon diaphragm having stress-sensitive piezoresistive regions formed by the localized diffusion of impurities have been theoretically and experimentally investigated. The longitudinal and transverse piezoresistance effects are discussed and the results are applied to the stress pattern of a deformed diaphragm. The conditions under which the stress in the diaphragm varies linearly with applied pressure are discussed and good agreement between the predicted and measured sensitivity is found in both the linear and nonlinear cases.