A method for simulating semiconductor devices includes running ensemble Monte Carlo (EMC) simulations of a plurality of semiconductor devices having a first plurality of configurations in a Design of Experiment (DoE) space to produce EMC results. Mobility parameters are extracted across the DoE space from the EMC results. A response-surface mobility model is constructed using the extracted mobility parameters. The response-surface mobility model is used to run a drift-diffusion simulation of a semiconductor device with a different configuration from the first plurality of configurations.