HIGH-MOBILITY BETA-SIC EPILAYER PREPARED BY LOW-PRESSURE RAPID THERMAL CHEMICAL-VAPOR-DEPOSITION ON A (100)SILICON SUBSTRATE

The mobility of beta-SiC thin films grown on (100) Si substrates by lo w-pressure rapid thermal chemical vapor deposition (LP-RTCVD) has been found to have a 200% improvement over that prepared by conventional l ow-pressure CVD. The SiC growth is achieved using a C3H8-SiH4-H-2 reac tion gas system at a reduced pressure of 2.5 Torr. Both X-ray and tran smission electron microscopy patterns show that the grown layer is sin gle-crystal beta-SiC. The influence of the growth conditions on the el ectrical properties of the SiC layer was also investigated. It was fou nd that the maximum electron mobility can reach 254 cm(2) V-1 s(-1) fo r carrier concentrations of ( 1-4) x 10(17) cm- (3) and at substrate t emperature of 1150 degrees C. The electron mobility is the highest one reported to date for the low-pressure heteroepitaxial SiC films on Si substrates.