THE EFFECT OF ANNEALING ATMOSPHERES ON STRUCTURAL, ELECTRICAL AND OPTICAL PROPERTIES OF THE ATO FILMS PREPARED BY RF MAGNETRON SPUTTERING

Antimony-doped tin oxide (SnO2: Sb, ATO) films were deposited on 7059 corning glass substrate by radio frequency magnetron sputtering method using a commercial ceramic target with a mixture of SnO2 and Sb (6 wt.%) for application to transparent electrodes. The ATO film was deposited at working pressure of 5 mTorr and RF power of 175 W without substrate heating. The thickness of the deposited ATO films was about 150 nm using a surface profiler (alpha-step). The films were annealed at temperatures ranging from 300 to 600 degrees C in step of 100 degrees C using RTA equipment in vacuum and oxygen atmosphere, respectively. We investigated the effects of the post-annealing atmospheres on structural, electrical and optical properties of the ATO films. The results show that the increase of the annealing temperature improved the crystallinity of the ATO films, increased the grain size and improved electrical and optical properties, regardless of annealing atmospheres. The resistivity of the ATO films decreased significantly with higher annealing temperatures in vacuum and oxygen atmosphere. In the visible range from 400 to 800 nm, the optical transmittance of the ATO films increased over 90% at higher annealing temperature.