Original Field Plate to Decrease the Maximum Electric Field Peak for High-Voltage Diamond Schottky Diode

Diamond is a promising material for future high-voltage applications because of its high critical electric field. This property leads to new constraints on the used termination structure, especially in terms of an electric field value. For this reason, new termination architectures based on a field plate are proposed for diamond Schottky diodes. Using the finite-element simulations with the Sentaurus technology computer-aided design software, a new field plate structure has been proposed. Simple variations in the classic field plate architecture were sufficient to increase the breakdown voltage from 1632 to 2141 V at 700 K, but not to reduce the electric field value at the edges of the field plate. Several termination topologies have been proposed to solve this problem. Parametric simulations were used to optimize the geometrical termination structure in order to reduce the electric field peak value at its edge while maintaining a high breakdown voltage. The new solutions have helped to reduce the maximum electric field from 57 down to 22.7 MV/cm.