Origin of the Linear and Nonlinear Piezoresistance Effects in p-Type Silicon

Origin of the longitudinal and transverse piezoresistance of p-type silicon diffused layers as measured and analyzed by Yamada, Nishihara, Shimada, Tanabe, Shimazoe and Matsuoka is explored theoretically. A model of stress decoupling of the degenerate valence band into two bands of prolate and oblate ellipsoidal energy surface is shown to explain the qualitative feature of anisotropy, temperature dependence and the order of magnitude of the linear coefficients. On this basis, a further comparison is proposed between the model and the nonlinearity for conductivity, so as to establish the origin.