Atmospheric pressure plasma etching of silicon dioxide using diffuse coplanar surface barrier discharge generated in pure hydrogen

Abstract

We report on the method of dry etching of silicon dioxide (SiO2) layers by cold plasma treatment at atmospheric pressure in pure hydrogen using Diffuse Coplanar Surface Barrier Discharge (DCSBD). The SiO2 etching rate was estimated at ~1nm/min. The studied plasma process was found to be the composition of plasma induced reduction and etching. The changes in surface morphology of etched samples were observed by scanning electron microscopy. X-ray photoelectron spectroscopy analysis was applied to identify the surface chemical changes due to the reduction processes. Two regimes of plasma treatment were examined. While the dynamic treatment, where the treated surface was moved relative to the plasma source, led to a homogeneous process, the treatment in static conditions resulted in a stripe-type pattern on the surface of the samples reflecting the electrode structure of the plasma source. The results provide a basis for a new and simple way to prepare clean, native oxide free silicon surfaces in dry plasma process at atmospheric pressure.