Plasma production with DC discharge planar magnetron device for thin film preparation

Plasma production is studied with a planar magnetron device using permanent magnets in a DC discharge for thin film preparation. The minimum value of discharge threshold voltages is found to lie in a wide region of pressure*gap length in comparison to that in the normal discharge without the magnets, resulting in a more stable discharge. Strongly inhomogeneous ion density in the radial direction is observed in a region close to the magnetics under the cathode to form a visible ring. Primary electrons and high electron temperatures are observed around the cathode, while the ion temperature is spatially homogeneous. The drift velocity caused by the effect of the electric and magnetic fields is directly measured to keep the value roughly constant in the longitudinal direction. A typical thin film of SnO2 prepared by the plasma CVD technique in this device is presented.