This paper presents benchmark test results of various surface potential based charge-sheet models. Compared with the results from the Pao-Sah model, most charge-sheet models produce certain degree difference in different operation regions. In some cases the simplified approximations even result in an incorrect trend in the inversion charge prediction. In order to model the channel current, a semi-empirical channel current equation in the surface potential based charge-sheet models is used and this leads to inconsistency between the channel current and channel charge, and some channel current errors. The benchmark tests indicate that these charge sheet models require some improvements to maintain the inherent device physics and high accuracy of the Pao-Sah model. (c) 2005 Elsevier Ltd. All rights reserved.