Characterization of inverted pyramidal hollow cathode microplasma devices operating in reactive gases for maskless scanning plasma etching

In the cantilever-based microplasma etching system proposed by our group, the stable discharge characteristics of microplasma device in reactive gases is the foundation of the maskless scanning etching of material. In this paper, the cantilever probe integrated with 100 μm2 inverted pyramidal hollow cathode microplasma device and nano-aperture at the hollow tip is successfully fabricated. The electrical and optical characteristics of the dc-driven microplasma devices operating in SF6, CHF3 reactive gases and their mixtures with Ar at different gas pressure are investigated. The etching profile and etching rate for silicon in SF6 microplasma exported from the nano-aperture are simulated to predict the etching effect under maskless microplasma etching system. The results of this paper may lay a foundation for upcoming experiments of maskless scanning plasma etching of silicon and its compounds, and also have implications in microplasma material processing in reactive gases using other devices configuration.