16 kV, 1 cm~2, 4H-SiC PiN Diodes for Advanced High-Power and High-Temperature Applications

摘要

In this work, we report our recently developed 16 kV, 1 cm2,4H-SiC PiN diode results. The SiC PiN diode was built on a 120 urn, 2×10~(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℃ to 200℃. At high injection-current density (J_F) of 350 ~ 400 A/cm~2, the differential on-resistance (R_(ON,diff)) of the SiC PiN diode decreased from 6.08 mΩ-cm~2 at 20℃ to 5.12 mQ-cm2 at 200℃, resulting in a very small average temperature coefficient of -5.33 μΩ·cm2/℃, while the forward voltage drop (V_F) at 100 A/cm2 reduced from 4.77 V at 20℃ to 4.17 V at 200℃. 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,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 μA at 16 kV at room temperature.