Strained Si channel MOSFETs with embedded silicon carbon formed by solid phase epitaxy

Abstract

Current drive enhancement is demonstrated in sub-40 nm NFETs with strained silicon carbon (Si:C) source and drain using a novel solid-phase epitaxy (SPE) technique for the first time. The very simple process uses no recess etch or epi deposition steps, adds minimal process cost, and can be easily integrated into a standard CMOS process. With a record high 1.65 at% substitutional C concentration in source and drain, 615 MPa uniaxial tensile stress was introduced in the channel, leading to a 35% improvement in electron mobility and 6% and 15% current drive increase in sub-40 and 200 nm channel length devices respectively. (Keywords: silicon carbon, MOSFET, strained Si, mobility and solid phase epitaxy).