Experimental Demonstration and Analysis of a 1.35-kV 0.92-m Ω · cm² SiC Superjunction Schottky Diode

This paper presents the fabrication, experimental analysis and electrical characterization of the first functional SiC superjunction (SJ) device. A trench-etching-and-sidewall-implant method has been developed to implement the SJ principle on a SiC Schottky diode. Several key process steps, including deep trench etching, ion implantation, and high-temperature annealing, are found to have noticeable influences on the device performances. The corresponding influences are studied by both simulation-aided theoretical analysis and experimental measurements. The highest measured cell blocking voltage was 1350 V, which achieves 95% of the simulated blocking voltage for the perfectly charge-balanced SJ structure. The measured device specific on-resistance was 0.92 mΩ · cm2. The SJ drift region specific on-resistance as low as 0.32 mΩ · cm2was obtained after subtracting the substrate resistance. This result successfully breaks the SiC 1-D unipolar limit.