Isothermal current-voltage characteristics of high-voltage silicon carbide rectifier p-i-n diodes at very high current densities

摘要

It is shown that, at high current densities corresponding to current surges, the isothermal current-voltage characteristics of high-voltage silicon carbide diodes cannot, in principle, be measured experimentally if the lifetime of nonequilibrium carriers is high enough for effective modulation of the base resistance. In such cases, isothermal current-voltage characteristics must be 'reconstructed' from experimental pulse current-voltage curves by comparison with an adequate analytical or numerical model. A procedure of this kind is performed for high-voltage 4H-SiC rectifier diodes with a record-breaking high carrier lifetime τ of 3.7 μs at room temperature.