Modeling and Optimal Device Design for 4H-SiC Super-Junction Devices

In this paper, a new and easy-to-implement analytical model is developed for the breakdown voltage and on-resistance of 4H-SiC superjunction devices. By considering the 2-D charge compensation effects, electric field distribution along the critical path has been modeled, and the device breakdown voltage has been calculated. Charge imbalance effects have also been accounted for. Results from the model have been validated by extensive numerical simulation for a large variety of device dimensions and doping concentrations. The proposed model is simple yet accurate for a relatively complicated and challenging structure. Through a device design example with a given set of constraints, it has been demonstrated that the proposed model can quickly provide an optimum structure for what might take weeks through numerical simulation. It can therefore provide useful guidelines for future developments of superjunction devices on 4H-SiC.