Measurement of Plasma Parameters in Low Temperature High Density Hollow Cathode Plasma Jet Working in Magnetic Field

Abstract

Low temperature low pressure hollow cathode plasma jet system working in static magnetic field was investigated by means of time resolved Langmuir probe technique. The hollow cathode discharge was excited in a cylindrical nozzle fabricated from Ti by continuous DC, pulsed DC, continuous wave radio-frequency (RF) and pulse-modulated RF power. Pure Ar was used as working gas. Electron distribution, electron density, and effective electron temperature were measured and compared between the different plasma jet excitation modes. Time evolution of plasma parameters was studied and compared with time evolution of power absorbed in the discharge in pulsed DC and pulse-modulated RF discharge excitation modes.

Ion current to a substrate in the pulsed dc hollow cathode plasma jet deposition system

“…The existence of slightly positive plasma potential in a DC driven hollow cathode plasma jet at a certain distance from the nozzle and similar experimental conditions was recently found in [12]. It was also found earlier [8] that the electron temperature in the active phase of the DC driven HCPJ is comparatively low. Hence the electron current to the grounded probe can be reduced down to the level of the ion current by even only small retarding voltage and the positive ion current component to the grounded probe cannot be neglected.…”

“…The first term on the right-hand side of ( 2) is assumed to be proportional to the mean discharge current during the pulse. This assumption is based on the fact that j i is directly proportional to the density of the charged particles that is in turn proportional to the discharge current in the HCPJ under the studied conditions [8]. The discharge current is further assumed to be zero in the afterglow region, which is well satisfied, see figure 2(a).…”

“…The hollow cathode plasma jet (HCPJ) [7,8,9] is a low-temperature sputtering device working at pressures approximately from 0.1 Pa to 100 Pa. Its deposition rate is comparable to the usual deposition rate of magnetrons. It is favourable for depositions on substrates with complicated shapes or into holes because of the jet-like character of the discharge.…”

“…The aim of this work is to study the ion current to a negatively biased substrate in a pulsed direct current (dc) hollow cathode plasma jet system for deposition of thin films. The hollow cathode plasma jet (HCPJ) [7][8][9] is a low-temperature sputtering device working at pressures approximately from 0.1 to 100 Pa. Its deposition rate is comparable to the usual deposition rate of magnetrons. It is favourable for depositions on substrates with complicated shapes or into holes because of the jet-like character of the discharge.…”

Electrical Probe Diagnostics of the Hollow Cathode Plasma Jet System for Deposition of TiOx Thin Films

“…Grounded poles of static electromagnet are placed close to the nozzle outlet for higher intensity and better stability of the discharge. The discharge can be operated in a continuous DC, a pulsed DC, an RF, or a pulse-modulated RF mode [10]. A continuous DC mode of discharge excitation was used, with titanium nozzle of internal diameter d n = 5 mm, and with argon flowing through the nozzle as the working gas.…”