Characteristics of silicon carbide Schottky diodes

The band gap of silicon carbide is 2.8 times that of silicon (wide bandgap), reaching 3.09 electron volts. Its insulation breakdown field strength is 5.3 times that of silicon, up to 3.2MV/cm, and its thermal conductivity is 3.3 times that of silicon, at 49w/cm • k. It, like silicon semiconductor materials, can be used to make junction devices, field-effect devices, and Schottky diodes in contact with metals and semiconductors. Its characteristics are:

(1) Silicon carbide single carrier devices have thin drift regions and low on state resistance. 100-300 times smaller than silicon devices. Due to its small on resistance, silicon carbide power devices have low forward losses;

(2) Silicon carbide power devices have high breakdown voltage due to their high breakdown electric field. For example, the voltage of commercial silicon Schottky diodes is less than 300V, while the breakdown voltage of the first commercial silicon carbide Schottky diode has reached 600V;

(3) Silicon carbide has high thermal conductivity;

(4) Silicon carbide devices can operate at higher temperatures, while the maximum operating temperature of silicon devices is only 150oC;

(5) Silicon carbide has high radiation resistance;

(6) The forward and reverse characteristics of silicon carbide power devices vary very little with temperature and time, indicating good reliability;

(7) Silicon carbide devices have excellent reverse recovery characteristics, with low reverse recovery current and low switching losses;

(8) Silicon carbide devices can reduce the volume of power devices and lower circuit losses.