THERMOELECTRIC STUDY OF THE TRENCH-GATE POWER VDMOS TRANSISTOR

In this paper, the 2-D numerical analysis is used to investigate the e lectro-thermal performance of a trench power VDMOS transistor having a much reduced quasi-saturation effect over the conventional VDMOS stru cture. Taking into account all the appropriate physical mechanisms, th e analysis self-consistently solves Poisson's equation, the electron c ontinuity equation and the heat flow equation. The results show that t he trench structure introduced enables the device to operate at higher current levels due to a favorable change in current density distribut ion within the device. However, these two effects can increase the sel f-heating of the device, decrease the forward current and degrade the thermal stability of the new structure. Nevertheless the new device is still found to provide a higher quasisaturation current than the conv entional VDMOS device even when thermal effects are taken into account .