A synchronized emissive probe for time-resolved plasma potential measurements of pulsed discharges

作者：Sanders Jason M^*; Rauch Albert; Mendel**erg Rueben J; Anders Andre

来源：Review of Scientific Instruments, 2011, 82(9): 093505.

DOI：10.1063/1.3640408

• discharges (electric)
• plasma materials processing
• plasma probes
• plasma transport processes
• sputtering

A pulsed emissive probe technique is presented for measuring the plasma potential of pulsed plasma discharges. The technique provides time-resolved data and features minimal disturbance of the plasma achieved by alternating probe heating with the generation of plasma. Time resolution of about 20 ns is demonstrated for high power impulse magnetron sputtering ( HIPIMS) plasma of niobium in argon. Spatial resolution of about 1 mm is achieved by using a miniature tungsten filament mounted on a precision translational stage. Repeated measurements for the same discharge conditions show that the standard deviation of the measurements is about 1-2 V, corresponding to 4%-8% of the maximum plasma potential relative to ground. The principle is demonstrated for measurements at a distance of 30 mm from the target, for different radial positions, at an argon pressure of 0.3 Pa, a cathode voltage of -420 V, and a discharge current of about 60 A in the steady-state phase of the HIPIMS pulse.

• 出版日期2011-9