Reactive ion etching of monocrystalline, polycrystalline, and amorphous silicon carbide in CF4/O2 mixtures

Reactive ion etching of monocrystalline and polycrystalline β-SiC and hydrogenated amorphous a-SiC:H in CF4/O2 mixtures was investigated. The a-SiC:H films, deposited by plasma-enhanced chemical vapor deposition, had the highest etch rate while monocrystalline β-SiC had the lowest etch rate at all compositions of the CF4/O2 mixture. The etch rates for the three materials increased with the addition of oxygen to CF4 and reached a maximum, but the maxima occurred at different compositions due to different rates of oxide formation.