STEP-CONTROLLED EPITAXIAL-GROWTH OF ALPHA-SIC AND APPLICATION TO HIGH-VOLTAGE SCHOTTKY RECTIFIERS

6H- and 4H-SiC were homoepitaxially grown by step-controlled epitaxy. N-type 6H- and 4H-SiC epilayers with a carrier concentration of 10(16)cm(-3) showed mobilities of 351 and 724cm(2)/Vs at room temperature, 6050 and 11000cm(2)/Vs at 77K, respectively. Isothermal capacitance transient spectroscopy (ICTS) measurements revealed that the epilayers have very few electron traps (<10(13)cm(-3)). Schottky rectifiers with 10 mu m-thick epilayers demonstrated high breakdown voltages of 600 similar to 1100V. Very low specific on-resistances of 1.2 similar to 1.7m Omega cm(2) were achieved utilizing 4H-SiC which has higher mobilities than 6H-SiC.