Subthreshold current in thick and thin-film SOI MOSFET transistors

Summary form only given. The subthreshold conduction regime in thick- and thin-film inversion-type SOI MOSFETs is studied in detail. Using the depletion approximation, a 1-dimensional analytical expression for the subthreshold slope is derived. The model accounts for the influence of the front and back interface properties (D_it ) on the subthreshold swing in the thin-film regime. The coupling between front and back surface potential, and the role of backside conduction on the front interface characteristics, are accounted for. The analysis covers the case where the front-channel conduction dominates and there is full depletion of the SOI film; the classical formula still holds. However, when the SOI film is fully depleted from the front side but accumulation holds at the back side (depending on the back-gate bias), the back-channel conduction dominates