Etch rate and surface morphology of polycrystalline β-silicon carbide using chlorine trifluoride gas

Etch rates of polycrystalline β-silicon carbide (SiC) substrate in a wide range from less than one to more than 10 μm/min are obtained using chlorine trifluoride gas in ambient nitrogen at 673-973 K and atmospheric pressure in a horizontal reactor. Over the chlorine trifluoride gas concentrations of 10-100% used in this study, the etch rate increases at the substrate temperatures between 673 and 773 K. Additionally, the etch rate at temperatures higher than 773 K is independent of the substrate temperature, similar to the one obtained using chlorine trifluoride gas concentration of 100%. The root means square roughness of etched surface tends to be small at high temperatures and high chlorine trifluoride gas concentrations. The polycrystalline β-SiC etch rate can be adjusted using a combination of gas flow rate, chlorine trifluoride gas concentration, and substrate temperature in order to obtain surfaces suitable for various purposes.