New and versatile minature microwave plasma source

Miniature Microwave Inductively Coupled Plasma (MMWICP) source is characterized by means of Optical Emission Spectroscopy (OES) in nitrogen gas flow, which gives the information on basic plasma properties. Depending on the incident power the discharge runs in E-mode or in more efficient H-mode. The high resolution radial images of the source reveal different morphologies of different discharge modes. The measurements show an unexpected limitation in dissipated power, accompanied by spontaneous transition from H- to E-mode. The efficiency of the source is high: about 67% of incident power (P0) is deposited in the discharge, which is estimated from OES