The Reasearch On Power MOS Device Model

Power MOS is a novel power electronic switching devices, which is developed on the basis of integrated circuit technology. LDMOS and VDMOS are typical representatives of the Power MOS, and they are also the main devices for PIC. But there is not an effective equivalent circuit model for Power MOS. Therefore, it is very important to establish the Power MOS (LDMOS and VDMOS) model for the circuit simulation.Firstly, after studying physical characteristics of Power MOS in dedail, both a physical model in the channel region and a physical model in the drift region for Power MOS (LDMOS and VDMOS) are proposed in the dissertation. In this dissertation, for the double diffused channel region of LDMOS, where the channel dopping is a variable, so the relationship between current and voltage of channel region is obtained by analytical method. Then a more accurate and effective model for channle region is obtained. For the drift region of LDMOS, a differential equation concerning the electric field of the drift region, which is based on the electric field distribution and electric field’s influence on eletron mobility. Moreover, it can be solved by analytical method, so a more accurate and effective model for drift region is obtained.Secondly, a physical model of channel region for VDMOS is also obtained. According to the differential equation concerning the electric field of the drift region, the physical model of drift region is also obtained. Compared with the simulation results of MEDICI, a more accurate and effective model for LDMOS and VDMOS is established.Lastly, base on the physical model, an equivalent circuit model for Power LDMOS and Power VDMOS is proposed. In order to apply the model to the PIC design, all kinds of circuit simulation software are investigated in detail. Finally, the equivalent circuit model are embedded into SABER successfully. According to the simulation results, accuracy and effectiveness of the model is validated.