Research of p ‐ i ‐ n Junctions Based on 4 H ‐SiC Fabricated by Low‐Temperature Diffusion of Boron

Novel method of boron diffusion at low temperatures between 1150 and 1300°C is used for the formation of both p ‐ i SiC junction and i ‐region in one technological process. As the junction formation conditions in this method are essentially different from those in the conventional diffusion (low temperatures and process of diffusion are accompanied by formation of structure defects), it is of special interest to identify advantages and disadvantages of a new method of diffusion. Developed SiC p ‐ i ‐ n junction diodes have fast switching time, and the duration of the reverse recovery current is less than 10 ns with a breakdown voltage of 120–140 V. Fabricated diodes possess capability to operate at temperatures up to 300°C. As the temperature of diffusion process is lower than the melting temperature of silicon, this new technology allows fabrication of diodes on the base of SiC/Si epitaxial structures.