Low temperature chemical vapor deposition growth of beta-SiC on (100) Si using methylsilane and device characteristics

The growth properties of beta-SiC on (100) Si grown by rapid thermal chemical vapor deposition, using a single precursor (methylsilane) without an initial surface carbonization step, were investigated. An optimun growth temperature at 800 degrees C was found to grow single crystalline materials. A simple Al Schottky barrier fabricated on n-type SiC grown on Si substrates exhibited a ''hard'' reverse breakdown of 13 V with a positive temperature coefficient of 2 X 10(-5)degrees C-1 up to 120 degrees C, indicating an avalanche mechanism. A Pt Schottky barrier fabricated on n-type SiC grown on tilted Si substrates to improve the surface morphology exhibited a breakdown voltage of 59 V, with a negative temperature coefficient. From the analysis of the electrical field distribution, the breakdown probably occurred at interface defects between SiC and Si, as suggested by Raman spectroscopy. To investigate minority transport behavior, SiC/Si heterojunction bipolar transistors (HBTs) were fabricated and compared to Si bipolar junction transistors. The collector currents of the SiC/Si HBTs were similar to those of Si control transistors, because both devices had the same base structures. Compared to Si control transistors, the base currents of SiC/Si HBTs increased. It seems that the interface defects between Si and SiC act as recombination centers to deplete back-injected holes, instead of being the barrier to stop hole currents, and thus to increase the base currents of SiC/Si HBTs. (C) 1997 American Institute of Physics. [S0021-8979(97)03921-2].