Abstract: An analytical non-linear model including surface-state effect is proposed for 4H-SiC power MESFET's with which the impact of suface damage at the ungate recess region caused by the dry-etching process on the output steady-state characterization can be illustrated clearly.The model has the advantage in very simple calculations over the 2D numerical simulations, therefore suitable for process analysis of SiC power MESFET's.