Semiconductor Devices and Modeling

For grid-connected power electronics applications, there is a need for power switches that can operate at high voltage, at high temperature, and at high switching frequencies. A power switch device realized using a wide bandgap material, such as SiC or GaN, can provide superior performance as compared to a conventional silicon device, due to its material property advantages. One barrier to widespread adoption of wide bandgap semiconductor devices is the availability of high fidelity compact models for circuit simulation. Without a model to accurately portray the behavior of the devices, circuit designers are unable to predict the performance advantages seen by using these materials and thus are not likely to insist on their use over traditional silicon devices.

The project goal is to develop a high-performance compact model for GaN semiconductor devices. A compact model is a nonlinear ordinary differential equation-based representation of the semiconductor device behavior. If this behavior is that of the charge movement and current flow within the device as a function of externally applied voltages and currents, then we refer to it as a physics-based model. Often the physical equations used to describe the device behavior must be approximations to partial differential equations in two or three dimensions. The challenge that faces all compact modelers is to make rational approximations while simultaneously faithfully reproducing device characteristics and formulating the model so that it executes fast with no convergence problems.