Multiband quantum transport simulations of ultimate p-type double-gate transistors: Influence of the channel orientation

Abstract

We present a ballistic real-space six-band k.p transport model to study the influence of the channel orientation in double-gate p-type metal-oxide-semiconductor (pMOS) transistors. The six-band k.p Hamiltonian is integrated into a self-consistent two-dimensional ballistic transport simulator based on the nonequilibrium Green’s function formalism. The impact of the transport direction is analyzed as a function of the Si transistor channel length. We show that direct source-drain tunneling strongly degrades the subthreshold behavior in short [110]-oriented transistors. This result contradicts the commonly accepted idea that [110] channel orientation provides the best performances for pMOS devices.