Anisotropic etching of silicon in SF6 plasma

Abstract

The reactive ion etching of silicon in SF6 plasma is considered. During the experiment, silicon substrates are etched in SF6 plasma at different pressures and energies of incident ions. High etching anisotropy is achieved decreasing the pressure in the reactor and increasing the energy of the bombarding ions. The obtained experimental measurements are compared with theoretical calculations. It is determined that the temperature of the sidewalls decreases with the decrease of concentration of F atoms due to suppressed plasmochemical etching of silicon. The etching anisotropy increases with the decrease of concentration of F atoms due to decreased desorption of SiF4 molecules.