The growth and structure of RF sputtered indium tin oxide thin films

Indium tin oxide films have been grown by reactively sputtering an indium/tin metallic alloy target in argon-oxygen mixtures. Growth parameters and annealing conditions have been optimized at low temperatures. Reactively sputtered oxide films were highly insulating and did require a post-deposition annealing treatment in a reducing ambient, to become highly transparent and conducting. A new annealing ambient, cracked ammonia, has been found to be very effective and economical. Films have been characterized for their structure and morphology by electron diffraction and scanning electron microscopy respectively. Relative advantages of annealing in cracked ammonia over nitrogen-hydrogen mixtures employed by other workers have been discussed. Films with preferred orientation, high optical transmission (∼ 95%) and low electrical resistivity (3 × 10⁻⁴ ω cm) have been obtained.