Analysis of the potential distribution in the channel region of a platinum silicided source drain metal oxide semiconductor field effect transistor

An analysis of the effect of the source and drain Schottky diodes on the drain characteristics (I-drain vs V-drain) of a platinum silicided metal oxide semiconductor field effect transistor is presented. A back to back Schottky diode model is used to explained the "diode like" feature observed in the small V-drain regime. For two-dimensional device simulations indicate an abrupt voltage drop across the source Schottky diode which can be a significant fraction of the applied drain bias. The resulting virtual source potential (V-source', different from the applied source potential V-source) has been quantified as a function of applied drain bias, temperature, and channel length, based on simulations that have been calibrated with experimentally measured data. The physical basis for V-source' is described as the reverse breakdown mechanism of the source Schottky diode and as such is a strong function of source electrode tip sharpness, poly edge to silicide edge gap distance, and temperature. The implications of this effect on device performance is briefly discussed. (C) 1999 American Institute of Physics. [S0003-6951(99)01419-9].