Physical operation and device design of short-channel tunnel field-effect transistors with graded silicon-germanium heterojunctions

Abstract

Using graded silicon-germanium heterojunctions, the green tunnel field-effect transistor (TFET) can be scaled down into sub-10 nm regimes without short-channel effects. This work elucidates numerically the physical operation and device design of extremely short-channel TFETs with graded silicon-germanium heterojunctions for future low-power and high-performance applications. Critical device factors, such as the drain profile and bandgap engineering, were examined to generate favorable characteristics in the on-current, on-off switching, and off-leakage of very short TFETs. A mildly doped drain with a pure Ge source is preferred in designing the graded TFETs to optimize a desirable green transistor for low-power integrated circuits.