DEPOSITION OF EPITAXIAL BETA-SIC FILMS ON POROUS SI(1OO) FROM MTS IN A HOT-WALL LPCVD REACTOR

Epitaxial beta-SiC thin films were grown on modified Si(100) substrates from methyltrichlorosilane (CH3SiCl3 or MTS) in a hot wall reactor by using low pressure chemical vapor deposition (LPCVD). At 1150 degrees C, the growth rate of the beta-SiC films was 120 Angstrom/min. Epitaxial beta-SiC(100) thin films were deposited after the deposition time of 12.5 min. However, the crystallinity of the deposited films was influenced by the deposition time. For example, the occurrence of rotational beta-SiC(100) crystals and polycrystalline beta-SiC with a highly preferred orientation of (100) planes was obtained for the deposition time of 50 min. XRD and TEM showed the appearance of polycrystalline beta-SiC films with a preferred orientation of beta-SiC(111) after further increasing the deposition times (time greater than or equal to 75 min). At 1100 degrees C, polycrystalline beta-SiC films with poor surface morphology were observed even though the film had a preferred orientation of beta-SiC(100) for short deposition time (e,g., 12.5 min). Polycrystalline beta-SiC(111) film was obtained for the deposition time of 200 min at this temperature.