| This work details the analysis and development of a 4H-SiC power diode for use in a high frequency solid state transformer. A detailed theoretical analysis of previous work in the field of power diode development is provided, and a set of criteria is developed to select an optimal device for a SST application. Device physics for PiN, MPS, and JBS diodes are examined and evaluated based on these criteria. Based on the developed criteria, 4H-SiC diodes utilizing an ion-implanted anode were designed with the aid of 2-D numerical simulations, and fabricated using a developed process flow. The resulting diodes were characterized, and the results analyzed to explain the resulting electrical behavior. Based on the observed results, a second iteration of the ion-implanted planar MPS was designed to improve the electrical characteristics of the devices compared to the first run, and achieve higher breakdown voltage. The resulting diodes showed good forward and reverse performance, achieving a breakdown voltage of more than 10 kV. To further improve upon the device on-state performance, and to simplify the manufacturing process, a 2-mask high voltage 4H-SiC SPEED diode process is proposed, and the critical processes necessary for its implementation are detailed. |
