Second-order analytical modeling of thin-film SOI MOSFETs

Summary form only given. The authors discuss the importance and the modeling of some characteristics of thin-film SOI MOSFETs related to second-order physical effects. To assess the importance of these second-order effects, they have been incorporated in an analytical model developed for long channel SOI MOSFETs in linear operation. The model remains valid whether the SOI film is fully or partially depleted. The derivation of the model is presented. Comparisons with experimental measurements clearly demonstrate the larger range of applicability and the improved physical accuracy of the model. The influence of the second-order effects are determined by comparing theoretical results of first-order analyses and of the improved model; both analyses were realized using the same set of model parameters. The analysis clearly shows that a thin-film SOI MOSFET cannot be considered a fully depleted device over its whole range of operation. Such an approximation could also lead to dramatic mismodelings of the overall physical behavior of the device