Seminumerical simulation of dispersive transport in the oxide of metal-oxide semiconductor devices

Abstract

Understanding and modeling of the device degradation mechanism in a metal-oxide field-effect transistor either due to hot carriers or ionizing radiation require simulation of hole /H⁺ ion transport in oxides. Because of its dispersive nature continuous-time random-walk-based techniques are used for such simulations. A numerical technique to simulate dispersive transport of holes and H⁺ ions in amorphous SiO₂ is described. Normalized flatband voltage shift and interface-state density were computed as a function of time and compared with published experimental data. Simulation results show that numerical approach is accurate. Numerical simulation results also show that choice of trial functions for arbitrary value of dispersive parameter a is in general accurate; however, compared to trial function solutions, the numerical approach could be easily extended to two dimensions and integrated with conventional device simulators.