Langmuir probe study of a titanium pulsed filtered cathodic arc discharge

Abstract

A Langmuir probe has been used to make measurements of plasma parameters as a function of time at the substrate position in a magnetically-filtered pulsed cathodic arc discharge. Electron density, ne, and effective electron temperature, Teff, were calculated as a function of time from the I–V curves. The Druyvesteyn method was used to determine the electron energy distribution. Ion density was calculated using the assumption of plasma quasi-neutrality and an average ion charge state. Results show that over the plateau region (350–600 µs) of the pulse, the electron energy distribution is Maxwellian with Teff = Te = (10 ± 1) eV. During the rise and fall times of the pulse, the electron energy distribution is non-Maxwellian with an effective temperature of up to 15 to 20 eV during the rise time and ∼7 eV during the fall time. The electron density during the plateau is ne = (3.0–6.0 ± 0.5) × 1017 m−3.