(Invited) Strained Germanium Nanowire MOSFET with Low-Parasitic Resistance Metal Source/Drain

Abstract

We demonstrate metal S/D nanowire pFETs having a high-mobility strained Ge channel formed by doping-free processes. The large compressive strain as high as -3.9% resulted in a record high hole mobility (μ eff = 1992 cm2/Vs @ N s = 1.7x1012 cm-2) and a low contact resistivity (ρ c ~ 3.8x10-8 Ω cm2). Inserting a plasma-oxide (GeOx) inter-layer between the high-k dielectric and the strained Ge nanowire channel greatly improved not only the mobility but the cut-off characteristics. A low off-current (2.7x10-9 A/μm at V d = -0.5 V) was achieved for the device with the gate length of 45 nm thanks to the reduced interface state density.