16 kV, 1 cm2, 4H-SiC PiN Diodes for Advanced High-Power and High-Temperature Applications

In this work, we report our recently developed 16 kV, 1 cm(2), 4H-SiC PiN diode results. The SiC PiN diode was built on a 120 mu m, 2x10(14)/cm(3) doped n-type SiC drift layer with a device active area of 0.5175 cm(2). Forward conduction of the PiN diode was characterized at temperatures from 20 degrees C to 200 degrees C. At high injection-current density (J(F)) of 350 similar to 400 A/cm(2), the differential on-resistance (R-ON,R-diff) of the SiC PiN diode decreased from 6.08 m Omega.cm(2) at 20 degrees C to 5.12 m Omega.cm(2) at 200 degrees C, resulting in a very small average temperature coefficient of -5.33 mu Omega.cm(2)/degrees C, while the forward voltage drop (V-F) at 100 A/cm(2) reduced from 4.77 V at 20 degrees C to 4.17 V at 200 degrees C. This is due to an increasing high-level carrier lifetime with an increase in temperature, resulting in reduced forward voltage drop. We also observed lower R-ON,R-diff at higher injection-current densities, suggesting that a higher carrier lifetime is needed in this lightly doped n-type SiC thick epi-layer in order to achieve full conductivity modulation. The anode to cathode reverse blocking leakage current was measured as 0.9 mu A at 16 kV at room temperature.