On a simple and accurate quantum correction for Monte Carlo simulation

Abstract

We investigate a quantum-correction method for Monte Carlo device simulation. The method consists of reproducing quantum mechanical density-gradient simulation by classical drift-diffusion simulation with modified effective oxide thickness and work function and using these modifications subsequently in Monte Carlo simulation. This approach is found to be highly accurate and can be used fully automatically in a technology computer-aided design (TCAD) workbench project. As an example, the methodology is applied to the Monte Carlo simulation of the on-current scaling in p- and n-type MOSFETs corresponding to a 65 nm node technology. In particular, it turns out that considering only the total threshold voltage shift still involves a significant difference to a Monte Carlo simulation based on the combined correction of oxide thickness and work function. Ultimately, this quantum correction permits to consider surface scattering as a combination of specular and diffusive scattering where the conservation of energy and parallel wave vector in the specular part takes stress-induced band structure modifications and hence the corresponding surface mobility changes on a physical basis into account.