Optimization of SiC Schottky diode using linear p-top for edge termination

Abstract

The trade-off between on-state and off-state characteristics of 4H-SiC Schottky diode has been optimized using linear p-top in the edge termination structure. The advantage of linear p-top has been illustrated by comparing results of 4H-SiC Schottky diode with planar structure using Silvaco Atlas Technology-computer-aided-design (TCAD) simulation tool. The breakdown-voltage characteristic of the SiC Schottky diode is significantly improved with the linear p-top edge termination. The planar SiC Schottky diode shows less than 300-V breakdown voltage, while the linear p-top structure shows breakdown voltage greater than 800-V with forward voltage <;1.5-V. The pronounced improvement in the breakdown-voltage characteristics is attributed to the reduction of electric field at the Schottky contact edge well by the linear p-top edge termination. The change in forward voltage and breakdown voltage with the variation in length of P-top mask in the termination region is observed.