CHARACTERIZATION OF INDIUM TIN OXIDE AND AL-DOPED ZINC OXIDE THIN FILMS DEPOSITED BY CONFOCAL RF MAGNETRON SPUTTER DEPOSITION

Thin film properties (resistivity, sheet resistance, optical transmissivity, stability testing under RH85/85C conditions and film stress) were measured for indium tin oxide (ITO) and Al-doped Zinc Oxide (ZnO) (2 wt.% Al doped target) films deposited using a confocal RF magnetron sputtering system. A comparison was made between sample biasing and high temperature conditions with respect to these properties. The sample bias was applied by RF power (0 60 W) to the sample. For the high temperature runs, the samples were heated to temperatures of as high as 250 C. ITO was deposited with argon as the process gas; Al-ZnO was deposited with a small amount of hydrogen (from 0 to 1%) added to argon. We find that comparable qualities of films can be obtained by either sample biasing or high temperature processes for ITO and Al-ZnO in terms of sheet resistance and transmission. However, sample biasing resulted in significantly higher compressive stress. The sheet resistance of Al-ZnO was affected by addition of hydrogen. The optimal concentration of hydrogen was 0.33% for sample biasing and 0.5% for high temperature runs under the deposition conditions considered.