Low Temperature and Large-Area Deposition of 3C-SiC Films on Si by AC Plasma-Assisted CVD.

采用改进的等离子体电极在Si衬底上大面积沉积3C-SiC薄膜。为了使等离子体更宽，将等离子体的压力从原来的170 Torr降低到100 Torr，并对等离子体电极进行了改进。在900-1000 ℃的衬底上形成的碳化层为单晶SiC薄膜，除衬底边缘外，表面光滑平整。衬底温度为950 ℃时，生长层的薄膜接近单晶，随着SiH_4流量的增加，生长层中有多晶相和SiC球形颗粒的趋势。当SiH_4喷嘴与衬底的距离增大时，生长层相对光滑平整，没有SiC球形颗粒。但它们都是多晶SiC薄膜，Si源在生长表面的过量供给使生长层为多晶相。也就是说，通过适当地供给SiH_4气体和直流偏压，可以在较低的衬底温度下形成完整的SiC单晶生长层。

Large area depositions of 3C-SiC films on Si have been investigated by modified plasma electrode. To make the plasma wider, the pressure was reduced from 170 Torr of the previous pressure to 100 Torr and plasma electrodes were modified.SiC thin films were deposited on 60x40 mm^2 Si (100) wafer by AC plasma-assisted CVD technique. Carbonization layrs formed at the substrate of 900-1000ﾟC were monocrystalline SiC films with smooth and flat surfaces except of substrate edges. Nearly monocrystalline films of grown layrs were obtained at the substrate temperature of 950ﾟC.The grown layr had a tendency to include a polycrystalline phase and SiC spherical particles with increasing the flow rate of SiH_4. When making a distance of the SiH_4 nozzle and the substrate wider, The grown layrs were relatively smooth and flat without SiC spherical particles. However they were polycrystalline SiC films.The excess supply of Si sources onto the growing surface make growth layr polycrystalline phase. In other words, it is suggested that perfect monocrystalline SiC growth layr can be formed at low substrate temperature by supplying the SiH_4 gas and DC bias adequately.