SIMULATION OF THE TRANSIENT CHARACTERISTICS OF PARTIALLY-DEPLETED ANDFULLY-DEPLETED SOI MOSFETS

We present a numerical technique which employs a local-in-time initial guess for the transient simulation of SOI MOSFETs. Specifically, the goal of this work is to compute the transient drain current which exhi bits overshoot. A critical factor in such computations is the choice o f the initial guess at each time point after the gate ramp. Our numeri cal simulations have shown that the use of the previous time point sol ution as an initial guess in the Gummel iterations fails to predict th e decay in the drain current from its maximum overshoot value. This di fficulty is circumvented when the steady-state solution is used as a l ocal-in-time initial guess. We use the diagonally implicit Runge-Kutta method for the time domain descretization. A fixed-point iteration te chnique is employed for the space domain iterations. To demonstrate th e usefulness of the local-in-time method, numerical results of the tra nsient drain current for various device parameters, such as the silico n film doping, silicon film thickness and back-gate bias are presented .