In this paper, a new model of surface-channel strained-Si/SiGe NMOSFETs is derived based on the extension of non-quasi-static (NQS) circuit model developed previously for bulk-Si devices. Basic equations of the NQS MOS model have been modified to account for new physical parameters of strained-Si and relaxed-SiGe layers. In addition, the device steady-state self-heating is efficiently included without employing the thermal-flow analog auxiliary sub-circuits. From the comparisons of modelling results with numerical simulations and measurements, it is shown that a modified NQS MOS including steady-state self-heating can accurately predict the DC characteristics of strained-Si/SiGe NMOSFETs. (c) 2006 Elsevier Ltd. All rights reserved.