Investigation of a Hybrid Discharge Mode of a Pin-to-Plate DBD in Ar-Hexamethyldisilane and Its Influence on Thin Film Deposition

Abstract

The study reports on a hybrid discharge mode found by experiment and modelling in a pin-to-plate atmospheric-pressure dielectric-barrier discharge using argon with small admixtures of hexamethyldisilane (HMDS). Optical observations in the early stages of discharge operation reveal a unique discharge structure with a diffusive part and a strongly contracted, bright region in front of the grounded substrate. To investigate the observed discharge characteristics, fluid modelling of the plasma evolution during the ignition phase is performed. Modelling results reproduce the discharge behaviour, uncover the discharge dynamics, and reveal the role of relevant plasma-chemical processes. Surfaces of films deposited in the hybrid mode are covered by flat hillocks indicating a close relationship to filaments observed with the bare eye and in modelling.