Reduced carrier backscattering in heterojunction SiGe nanowire channels.

In this work, we investigate the effect of energy band profile modulation on carrier backscattering in SiGe nanowire (SGNW) heterojunction p-channel field effect transistors. The energy band profile is modulated by increasing the Ge mole fraction in nanowire channels as compared to source/drain regions using the pattern-dependent Ge condensation technique. The carrier backscattering characteristics of the fabricated heterojunction p-type SGNW transistors, extracted using a temperature-dependent analytical model, exhibited a decrease of 19% in hole backscattering coefficient in comparison to the reference planar devices with uniform Ge concentration. The reduction in backscattering coefficient is attributed to KT/q barrier layer thinning of the source-to-channel barrier for the holes as a result of the modulation in energy band profile caused by variation in Ge concentration. [ABSTRACT FROM AUTHOR]