Monte Carlo simulation of remote-Coulomb-scattering-limited mobility in metal–oxide–semiconductor transistors

An improved theory for remote-charge-scattering-limited mobility in silicon inversion layers is developed. The model takes into account the effects of image charges, screening, inversion layer quantization, the contribution of different subbands, oxide thickness, the actual distribution of charged centers inside the structure, the actual distribution of carriers in the inversion layer, the correlation of charged centers, and the charged centers sign. The model is implemented in a Monte Carlo simulator, where the effects of the ionized impurities charge, the interface trapped charge, and the contribution of other scattering mechanisms are taken into account simultaneously. Our results show that remote Coulomb scattering cannot be neglected for oxide thicknesses below 2 nm, but that its effects for tox>5 nm are negligible. Good agreement with experimental results has been obtained.