A Low-Field Mobility Model for Bulk, Ultrathin Body SOI and Double-Gate n-MOSFETs With Different Surface and Channel Orientations—Part I: Fundamental Principles

An easy-to-implement electron mobility model, which accurately predicts low-field mobility in the channel of bulk MOSFETs and UTB-SOI FETs fabricated on different crystal orientations is developed. The model accounts for the influence of surface orientation and in-plane current-flow direction on effective masses, subband repopulation and scattering rates. The paper is divided in two parts. In Part I the general features of the model are presented taking into account phonon, Coulomb and surface roughness scattering. Band and repopulation effects are addressed based on the solution of the Schr¨odinger-Poisson equations. The effects of interface states and ultra-thin body are treated in the accompaning Part II.