Performance enhancement of uniaxially-tensile strained Si NW-nFETs fabricated by lateral strain relaxation of SSOI

We present experimental results on mobility enhancement and on-current gain in Si NW-FETs fabricated on SOI and biaxially strained SOI. In SSOI long channel devices a 2.3 times larger mobility and similar on-current improvement compared to SOI are measured. Measurements on SSOI NW-FETs with different length to width ratio highlight that mobility enhancement due to lateral strain relaxation sensitively depends on the device geometry due to the size dependence of lateral strain relaxation. For maximum performance enhancement due to lateral strain relaxation SSOI devices must have a large length to width ratio. Furthermore, the geometry dependence of lateral strain relaxation to achieve uniaxial tensile strain is investigated with finite element simulations.