Electrical characterization of Ω-gated uniaxial tensile strained Si nanowire-array metal-oxide-semiconductor field effect transistors with - and channel orientations

Abstract

Nanowire-array metal-oxide-semiconductor field effect transistors (MOSFETs) were fabricated along <110> and <100> crystal directions on (001) un-/strained silicon-on-insulator substrates. Lateral strain relaxation through patterning was employed to transform biaxial tensile strain into uniaxial tensile strain along the nanowire. Devices feature ideal subthreshold swings and maximum on-current/off-current ratios of 1011 for n and p-type transistors on both substrates. Electron and hole mobilities were extracted by split C–V method. For p-MOSFETs an increased mobility is observed for <110> channel direction devices compared to <100> devices. The <100>n-MOSFETs showed a 45% increased electron mobility compared to <110> devices. The comparison of strained and unstrained n-MOSFETs along <110> and <100> clearly demonstrates improved electron mobilities for strained channels of both channel orientations.