SIC/SI HETEROJUNCTION DIODES FABRICATED BY SELF-SELECTIVE AND BY BLANKET RAPID THERMAL CHEMICAL-VAPOR-DEPOSITION

SiC/Si heterojunction diodes have been fabricated by two different rapid thermal chemical vapor deposition (RTCVD) processes: a localized self-selective growth and blanket growth. The self-selective growth of crystalline cubic (beta) SiC was obtained by propane carbonization of the Si substrate in regions unprotected by an SiO2 layer, producing planar diodes. Mesa diodes were fabricated using the blanket growth of polycrystalline beta-SiC produced by the decomposition of methylsilane (CH3SiH3). The SiC/Si heterojunction diodes show good rectifying properties for both device structures. Reverse breakdown voltage of 50 V was obtained with the self-selective SiC/Si diode. The mesa diodes exhibited even higher breakdown voltages (V-br) of 150 V and excellent ideality factors of 1.06 at 25 degrees C. The high V-br and good forward rectifying characteristics indicate that the SiC/Si heterojunction diode represents a promising approach for the fabrication of wide-gap emitter SiC/Si heterojunction bipolar transistors.