Electron mobility in silicon under high uniaxial strain

Abstract

In the pursuit of improving the performance of semiconductor devices, the manipulation of material properties through strain engineering has emerged as a promising avenue. In this work, the enhancement of the electron mobility in silicon has been experimentally investigated for uniaxial strain up to almost 1% along the [100] crystal direction. The experimental data have been obtained from n-doped silicon beams strained using four-point bending scheme. To complement the experimental measurements that present a mobility enhancement of about 65%, first-principles calculations have been conducted to determine the splitting of the conduction bands and the changes in the effective masses induced by the strain. A semi-empirical model is finally used to predict the undoped behavior, which forecast a mobility increase close to 1000 cm${}^2$V⁻¹s⁻¹ for a strain of about 1%.