Spectroscopic Analysis of Aluminum Plasma Produced by DC Magnetron Sputtering Technique

Abstract

This study explores the influence of argon pressure and applied voltage on plasma characteristics in a DC magnetron sputtering system. The discharge was created at working vacuum pressures ranging from 0.05 to 0.4 mbar using different applied voltages from 400 to 1200 V to investigate the relations between these parameters and emission intensities to predict the optimum point of sputtering efficiency of aluminum. The optimal working pressure was 0.3 mbar at the highest emission intensities of both sputtering gas and metal atoms, indicating maximum sputtering rate. Increasing the applied voltage caused higher emission intensity due to increasing energy delivered to the charged particles, leading to more ionization and excitation collisions. Plasma parameters comprising electron number density, electron temperature, plasma frequency, Debye length, and Debye number appeared to be related to working pressure and voltage. These study outcomes offer a valuable strategy for adjusting sputtering processes by fine-tuning working pressure and applied voltage while observing the characteristics of induced plasma.