A Guideline for electron mobility enhancement in uniaxially-strained (100)/(100) and (110)/(110) fin field effect transistors

Abstract

In this study, we analyze the stress effect in uniaxially strained (100)-And (110)-oriented fin field effect transistors (FinFETs) and determine which stress condition can effectively enhance electron mobility. Electron mobility is accurately calculated using a self-consistent Schrödinger-Poisson solver; thus, our simulation results show excellent agreement with the experimental data. The stress-induced mobility as a function of inversion density (Ninv) is calculated in the (100) and (110) orientations. The results show that the stress-induced mobility exhibits considerably different behavior for various stress conditions. In the (110) case, longitudinal tensile and transverse compressive stresses are very effective in increasing the mobility, and stress over 0.5 GPa can cause the (110) mobility to be larger than the (100) mobility. An in-depth analysis reveals that this phenomenon results from differences in the occupancy, momentum relaxation time (t) and conductivity mass changes as a consequence of different orientations and stress conditions. © Copyright 2017 American Scientific Publishers.