INFLUENCE OF CONTINUOUS AND DISCONTINUOUSDEPOSITIONS ON PROPERTIES OF ITO FILMS PREPAREDBY DC MAGNETRON SPUTTERING

摘要

Indium tin oxide (ITO) films were deposited on glass substrate without external heatingby DC magnetron sputtering with continuous deposition of 800 s (S1) and discontinuousdepositions of 400 s x 2 times (S2), 200 s x 4 times (S3) and 100 s x 8 times (S4). Thestructural, surface morphology, optical transmittance and electrical resistivity of ITOfilms were measured by X-ray diffraction, atomic force microscope, spectrophotometerand four-point probe, respectively. The deposition process of the S1 condition shows thehighest target voltage due to more target poisoning occurrence. The substrate temper-ature of the S1 condition increases with the saturation curve of the RC charging circuitwhile other conditions increase and decrease due to deposition steps as DC power turnson and off. Target voltage and substrate temperature of ITO films decrease when chang-ing the deposition conditions from S1 to S2, S3 and S4, respectively. The preferentialorientation of ITO films were changed from dominate (222) plane to (400) plane withthe increasing number of deposition steps. The ITO film for the S4 condition shows thelowest electrical resistivity of 1.44 x 10-3 Ω.cm with the highest energy gap of 4.09 eVand the highest surface roughness of 3.43 nm. These results were discussed from thepoint of different oxygen occurring on the surface ITO target between the sputteringprocesses which affected the properties of ITO films.