427 単結晶シリコン材料のピエゾ抵抗物性シミュレーション(T09-1 微小機械システムにおけるマイクロ・ナノ力学(1) MEMSにおけるマイクロ・ナノ力学,大会テーマセッション,21世紀地球環境革命の機械工学:人・マイクロナノ・エネルギー・環境)

Abstract

We have simulated the piezoresistivity in single-crystal silicon materials based on the first-principles calculations of model structures. Our novel approach to calculate the piezoresistance coefficients is valid qualitatively for electron transport in the multi-valley conduction band structure of n-type bulk silicon, in particular, the shear piezoresistance coefficient π_<44> can be presented clearly as a negative constant. For p-type bulk silicon, an easy additional procedure for the spin-orbit coupling in the valence bands gives an appropriate hole distribution and piezoresistance coefficients in a qualitative level. The calculation result that p-type <001> silicon nanowire will have a giant piezoresistivity is considered to be reliable.