Fully Self-Consistent Schrödinger Monte Carlo Transport Modeling of p-Channel Strained SiGe MOSFETs

S. Krishnan and D. Vasileska
CSSER, Arizona State University, US

Keywords: MOSFET device simulation, strained SiGe, quantum transport

Abstract:
Strained SiGe MOSFETs offer enhanced hole mobilities by reducing the in plane effective hole masses. Furthermore, the presence of a buried SiGe layer causes hole confinement therein, primarily due to the valence band offsets (which split due to strain), and surface roughness is not a big factor. Alloy scattering dominates instead. We investigate the transport in a 50 nm strained SiGe p-channel MOSFET (Fig. 1-left panel) using a fully self-consistent Schrödinger Monte Carlo transport model. The 2D eigenstates are constructed from a set of 1D eigenstates obtained by solving the Schrödinger equation along the depth in slices along the length direction. Real space transfer of holes into the Si cap region under high bias conditions is also modeled. Under such conditions, carriers begin to experience greater surface roughness scattering and the device essentially behaves as a conventional Si MOSFET and mobility degradation sets in. In the source and drain regions we treat the holes classically. Our low-field mobility data for this device structure are in excellent agreement with the experimental findings1 (Figure 1-right panel). Device simulations as described are currently in progress and the device transfer and output IV-characteristics will be presented at the conference.

Nanotech 2004 Conference Technical Program Abstract