Langmuir probe study of a titanium pulsed filtered cathodic arc discharge

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, n_e, and effective electron temperature, T_eff, 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 νs) of the pulse, the electron energy distribution is Maxwellian with T_eff ≤ T_e ≤ (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 n_e ≤ (3.0-6.0 0.5) × 10¹⁷ m ^-3.