Growth of nanocrystalline 3C-SiC a on Si substrate by Plasma-enhanced Chemical Vapor Deposition

Abstract

3C-SiC films were deposited on a silicon (100) substrate by a plasma-enhanced chemical vapor deposition (PECVD) technique using a gas mixture of SiCl4/CH4/H2/Ar in the temperature range between 1170oC and 1335oC. The Crystallinity of deposited films was investigated by varying the deposition temperature, input gas ratio, Rx [=CH4/(CH4+H2)], and r.f. power. The PECVD method effectively enhanced the deposition rate compared with TCVD (thermal chemical vapor deposition). The highest preferred orientation of deposited 3C-SiC layers was found to be the (111) plane. The crystallinity of 3C-SiC on the Si substrate was significantly influenced by the Rx value and improved with decreasing Rx. The free silicon was co-deposited with 3C-SiC. The content of free silicon was decreased with increasing the deposition temperature and decreasing the Rx value. 3C-SiC films which had a relatively good crystallinity were obtained at a deposition temperature of 1270oC, an input gas ratio of Rx=0.04, and an r.f. power of 60 Watt.