Effect of DC power on the AlN plasma of magnetron sputtered thin film

AlN thin films deposited at room temperature by reactive DC magnetron sputtering of Al target in pure argon and nitrogen atmosphere. Thin films were deposited on glass and silicon (Si) substrate at different DC power. The variation of DC power on the structural, electrical and optical properties of the films were investigated. Enhancement of crystallinity and conductivity was observed with increase in DC power. The optical characteristics of films, such as refractive index, extinction coefficient, and average thickness, were calculated by Swanepoel’s method using transmittance measurements. The refractive index and average roughness value of the films increased with film thickness. Film deposited on Si substrates at an DC power of 100W showed a minimum resistivity of 1.27x10Ωcm. The electrochemical behavior of the films was studied in 3.5% NaCl solutions using potentiodynamic techniques. The results indicate that AlN films grown at a higher power performed with a better electrochemical behavior compared to the lower deposition power. It has been observed that the film properties are greatly influenced by the plasma conditions during sputtering. DC plasma was studied using Langmuir Probe and Optical Emission Spectroscopy (OES). The plasma parameters such as ion density and electron temperature were determined and their dependence on properties of thin film deposited under similar plasma conditions were studied. Plasma parameters were determined for different DC powers keeping the constant distance.