Suppression of electron emission from cathode in photoemission-assisted Ar plasma

In order to improve the efficiency of the surface flattening process using photoemission-assisted plasma ion source, current-bias voltage characteristic and Ar⁺ ions/Ar atoms ratio in the plasma was investigated. The glow discharge starting voltage decreases by UV irradiation and a great number of Ar⁺ ions were irradiated to the substrate. On the other hand in PA Townsend discharge, the number of Ar⁺ ions reached at the substrate is smaller than that in glow discharge due to space charges near the cathode substrate.