Evaluation of Ballistic Transport in III–V-Based p-Channel MOSFETs

Ballistic transport in III-V semiconductors-based p-channel double-gate MOSFETs is theoretically evaluated. The valence band structure is calculated by solving the eight-band k · p Schrödinger and the Poisson equations self-consistently. A semiclassical ballistic model is employed to assess the hole transport properties. Ballistic characteristics are analyzed as a function of channel material, crystal orientation, and strain effect. The results indicate that Sb-based III-V materials can provide comparable drive current with the Ge counterpart. In addition, (110)/[1̅10] oriented devices exhibit better performance than other surface and transport directions whatever considered material. We also demonstrate that compressively strained GaSb devices outperform relaxed Ge in terms of ballistic current. According to our simulations, as effective oxide thicknessscales down to 0.5 nm, both the group IV and III-V p-channel devices can be assumed to operate in the classical capacitance limits, where the I
_D
-V
_G
characteristics are basically governed by the transport effective mass. As a consequence,I
_ON
enhancement is owing to the reduced transport effective mass whether it results from alternative materials, optimized transport directions, and strain effects.