Topology Optimization of Power Semiconductor Devices

Abstract

In this paper, topology optimization is applied to the design of power semiconductor devices. The doping density distribution of power semiconductor devices is optimized using a density-based topology optimization method. The density method is suitable for the design of power semiconductor devices because doping density can take on continuous values and is intrinsically free from the gray-scale problem. To verify the effectiveness of topology optimization, optimization was conducted for two types of two-dimensional design problems. At first, optimization of a p-n diode was performed to improve the trade-off between the breakdown voltage and on-resistance. This is formulated as a single-objective optimization problem with the Kreisselmeier-Steinhauser (KS) objective function of the electric field, which indicates the breakdown voltage characteristics, under the constraint of the on-resistance. By optimization, a p-i-n diode, which is a well-known diode structure, is obtained and the trade-off is improved. Next, optimization of an edge termination structure was performed to improve the breakdown voltage characteristics with the consideration of ion implantation, which is one of the fabrication processes used for semiconductor devices, under the process variation. The optimized structure obtained is ensured to be manufacturable and more robust with respect to the dose amount variation of ion implantation than the initial structure. These results demonstrate the effectiveness of topology optimization for the design of power semiconductor devices.