VARIATIONS IN MICROSTRUCTURE AND COMPOSITION OF INDIUM TIN OXIDE-FILMS WITH THE DEPOSITION TECHNIQUE

Indium tin oxide (ITO) films have been deposited by reactive d.c.-sput tering and also by the reactive thermal evaporation technique onto gla ss substrates. The relationship between the microstructure and composi tion of the ITO films was found to strongly depend on the deposition t echnique. In addition the application of pure water vapour as the reac tive sputtering atmosphere and its influence on the structural and com positional properties of the ITO films has been studied. X-ray diffrac tion investigations showed that all the films exhibited the bixbite st ructure of ln(2)O(3). No other crystalline phases were observed. Highl y crystallized ITO films have been obtained using the reactive thermal evaporation technique. These films show a large average grain size of about 80 nm and a very homogeneous morphology. In contrast the d.c.-s puttered ITO films have a smaller average grain size and a characteris tic texture. All deposited ITO films show an enlarged lattice constant compared to that of ln(2)O(3), A strong dependence of the chemical co mposition of the ITO films on the deposition technique and parameters was detected.