Ge-rich (70%) SiGe nanowire MOSFET fabricated using pattern-dependent Ge-condensation technique

Abstract

A top-down approach of forming SiGe-nanowire (SGNW) MOSFET, with Ge concentration modulated along the source/drain Si0.7 Ge0.3 to channel Si0.3Ge0.7 regions, is presented. Fabricated by utilizing a pattern-size-dependent Ge-condensation technique, the SGNW heterostructure PMOS device exhibits 4.5× enhancement in the drive current and transconductance Gm as compared to the homojunction planar device Si0.3Ge0.7. This large enhancement can be attributed to several factors including Ωgated nanowire structure, enhanced hole injection efficiency (due to valence band offset), and improved hole mobility (due to compressive strain and Ge enrichment in the nanowire channel). © 2008 IEEE.