Titanium dioxide thin films deposition by direct current hollow cathode magnetron sputtering

Abstract

Cylindrical hollow cathode magnetron sputtering (HCMS) system was used to deposit crystalline titanium dioxide thin films on p-Si (100) substrates. For a fixed pressure of 0.6 Pa total gas flow rate of 20 sccm and power of 55 W, the influence of the oxygen percentage in the Ar+O 2 gas mixture on the structural and surface properties of the films was studied by profilometry, XRD and AFM. The substrates were placed inside the hollow cathode at different positions along its symmetrical axis. Numerical simulations of cathode ion collection probability (CICP) were done in order to compare calculated data with the deposition process characteristics. The results indicate that the deposition rate and the surface roughness gradually decrease with the distance from the bottom of the cathode, due to the decrease of the CICP. The increase of the oxygen percentage in the gas discharge influences directly the deposition rate and decrease the surface roughness. The XRD analyses show that all the films are crystalline with predominant anatase (101) and rutile (110) orientations.