Study And Application Of The Radiation Effect On Silicon VDMOS

As a basic power device, the power switch VDMOS is widely used in the applications of power integrated circuits and power integrated system, such as switched-model power converters, automotive electronics, motor control, and so on, with its high switch speed, high breakdown voltage, low conduct resistance, and good thermal stability. Therefore, it is very important to study the physical and electrical characteristic of VDMOS. VDMOS is massively used in nuclear radiation and space radiation environments, so the research on the radiation model and the radiation characteristics of VDMOS is very important. The equivalent circuit models of the VDMOS in without radiation and radiation conditions are studied in this thesis.First, the equivalent circuit of the VDMOS is proposed based on the effect of physical structure and parasitic elements on the characteristics of the device. The device parameters of the equivalent circuit are extracted by the Model Editor program of the PSpice. This Spice model is suitable for modeling the static and dynamic switching characteristics. The simulation results with this model are in excellent agreement with the experiment data. The sub-circuit module used in PSpice for VDMOS is also proposed, which is useful for analysis and design of circuits of power VDMOSFET'sSecond, the radiation characteristics of the VDMOS and the total dose effect of the radiation on the VDMOS have been investigated. The radiation characteristics model of the VDMOS is proposed based on the total dose radiation effects on the MOS'electrical parameters. This model can be embedded in PSpice for simulating the radiation characteristics of VDMOS. It has been used in the switched-model power converters and the total dose radiation effect on the switched-model power converter circuit has been studied. This model is useful as a computer-aided design tool for analysis and design of VDMOS circuits which work in the radiation environments.