Experimental Study of the Discharge in the Low Pressure Plasma Jet Sputtering System

Abstract

This article reports on experimental study of the discharge in the low pressure plasma jet sputtering system operated in the continuous DC regime of the discharge excitation. Presented measurements were focused on the description of the working pressure impact on the basic discharge characteristics. The pressure dependence of the gas flow velocity from the nozzle was examined by means of Pitot tube. Further an approximate measurement of the discharge current spatial distribution was realized as well. The second half of the article presents results from Langmuir probe measurements under the conditions of low pressures in the range of units of pascals. These conditions are of special importance in some particular applications especially in preparation of thin layers with high crystallinity. Used experimental setup enabled to perform Langmuir probe diagnostic with spatial resolution both in the plasma jet axis direction and in the direction perpendicular to it.

The deposition of titanium dioxide nanoparticles by means of a hollow cathode plasma jet in dc regime

“…The low electron temperature is typical for this discharge type because almost the whole cathode fall is located inside or in the vicinity of the cathode. These values are in agreement with [16] and [24], but in the second reference much higher oxygen to argon ratios were used. The plasma potential is slightly negative when the probe is used in pure argon as in [16,24].…”

“…These values are in agreement with [16] and [24], but in the second reference much higher oxygen to argon ratios were used. The plasma potential is slightly negative when the probe is used in pure argon as in [16,24]. The negative value of the plasma potential can be explained by the low radial diffusion to the chamber walls at the working pressure of 100 Pa and the low electron temperature.…”

“…To achieve this with a magnetron an aggregation chamber provided by differential pumping is necessary [15]. Moreover, the velocity of a working buffer gas can be adjusted via its flow rate [16,17]. This influences the resident time of nanoparticles inside and outside of the hollow cathode and, consequently, influences the size of the nanoparticles deposited on the substrate.…”