Crystallinity control of SiC grown on Si by sputtering method

Abstract

We investigated a method of controlling the crystallinity of an n-type SiC (n-SiC) layer grown on a p-type 4°-off-axis Si(111) (p-Si) substrate by our sputtering method for use as SiC/Si devices. An n-SiC layer grown on p-Si at 810°C exhibits columnar 3C-SiC(111) crystal growth. However, it contains many defects near the n-SiC/p-Si interface. We then propose a method in which a 10-nm-thick nondoped SiC (i-SiC) interlayer is grown at a low temperature of 640°C prior to the growth of the n-SiC layer at 810°C, which results in a decrease in the number of defects at the SiC/p-Si interface and an intensive increase in the crystallinity of the n-SiC, compared with that of n-SiC grown at 810°C without the interlayer, probably via effective interlayer reconstruction and an enhancement in the crystallinity of the i-SiC interlayer itself during the n-SiC growth. Furthermore, the n-SiC/i-SiC-interlayer/p-Si structure was applied as a Si-based solar cell and the energy conversion efficiency of the n-SiC/p-Si solar cell effectively increased with the insertion of the i-SiC interlayer.