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 that 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 into 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 Schrödinger-Poisson equations. The effects of interface states and ultrathin body are treated in Part II.