Spectroscopic Diagnostics of AC Discharge in Magnetron Sputtering System

Abstract

This paper investigates the effect of the AC discharge frequency, and the magnetic field on the discharge characteristics of a cylindrical magnetron sputtering device operating at constant argon pressure. The AC argon discharge was produced by applied high voltage alternating 10 kV with frequencies 7 and 9 kHz. The optical emission spectroscopy technique was used to determine the effect of source frequency and magnetic field on emission spectra, glow discharge regions and other discharge parameters (such as T_e, n_e, λ_D and N_D). The emission spectra of an argon discharge at both source frequencies indicate that the emission intensity of Ar I and Ar II increases as the coil current increases. The emission intensities of the peak lines of Ar I and Ar II increase with increasing source frequency. An optical emission spectrometer was used to diagnose the effect of source frequency and magnetic field on the AC discharge properties using the Boltzmann plot method, the electron temperature was determined. The electron number density was calculated using Stark broadening. The data showed that the electron temperature, electron density, Debye length, and plasma parameters increased with increases in the coil current at both source frequencies. Moreover, the increase in source frequency causes increases in all discharge parameters.