The effect of hydrogen etching on 6H-SiC studied by temperature-dependent current-voltage and atomic force microscopy

6 H – SiC was etched with hydrogen at temperatures between 1000 and 1450°C. The etched Si-terminated face for the 6H-SiC wafer was investigated by atomic force microscopy and temperature-dependent current–voltage (I–V–T) measurements. Mechanical polishing damage was effectively removed by hydrogen etching at temperatures above 1250°C. Atomic force microscopy images revealed that very good surface morphology, atomic layer flatness, and large and large step width were achieved. Schottky diode characteristics were investigated in detail by current–voltage and temperature-dependent current–voltage measurements, and the results showed a transition from defect assisted tunneling to thermionic emission as the annealing temperature was increased from 1250 to 1450°C.