Low-temperature synthesis of $\alpha$-SiC nanocrystals

Thick SiC$_ x$ films have been deposited on a $c$-Si surface by radiofrequency (rf) magnetron sputtering (150 W, 13.56 MHz, Ar flow 2.4 L/h, 0.4 Pa) of graphite and silicon targets. The X-ray diffraction study shows that fast annealing of the SiC$_ x$ film deposited on the $c$-Si surface for 3 h leads to the low-temperature (970$^{\circ}$C) formation of hexagonal structural phases $\alpha$-SiC (6 $H$-SiC and other) along with the cubic modification of silicon carbide $\beta$-SiC. The IR spectroscopy has shown the formation of SiC nanocrystal nuclei due to the energy action of the rf plasma ions on the upper layer of the SiC film during its growth. The data of X-ray reflectometry demonstrate a high density of the films up to 3.59 g/cm$^2$ as a result of formation of dense C and SiC clusters in the layers under action of the rf plasma.