SOI and Bulk FinFET Alternatives from the Perspective of Strain Engineering

Abstract

The mechanical stresses in the channels of strain-engineered SOI and bulk FinFETs have been studied. The dependency of the charge carrier mobility on the channel geometries and crystal orientations was analyzed using a computer modeling based on a specially developed 2D FEM algorithm that enabled fast turnaround in conducting numerous iterative simulation experiments. It is shown that embedded SiGe stressors (eSiGe) formed in Source/Drain regions of FinFETs are the key element for enhancing drive currents of PFETs to the level comparable with NFETs. eSiGe stress-induced change of the hole mobility in SOI FinFETs is about half of what can be achieved in bulk FinFETs. To compensate this deficiency, SOI FinFET designers may consider alternative crystal orientations for Fins, strained SOI, and high quality Ge or III-V semiconductors on insulator.