AN ANALYTICAL MODEL OF PUNCHTHROUGH VOLTAGE OF SHORT-CHANNEL MOSFETS WITH NONUNIFORMLY DOPED CHANNELS

A simple and analytical model of the OFF state punchthrough voltage of MOSFETs with nonuniformly doped channels is presented. The model is based on geometrical analysis and uses the concept of punchthrough depth. The model accepts nearly exact doping profiles, instead of the step profile, which has limited application. Gaussian profiles and Pearson-IV type boron implantation profiles have been considered in this paper. The variation of punchthrough voltage with effective channel length, substrate bias, channel doping concentration, source-drain junction depth and gate-oxide thickness have been computed and good agreement with experimental results is obtained. Unlike analytical models presented earlier, this model correctly simulates the effect of substrate bias on punchthrough voltage. © 1990.