MICROGRAIN STRUCTURE INFLUENCE ON ELECTRICAL CHARACTERISTICS OF SPUTTERED INDIUM TIN OXIDE-FILMS

The relationship between micrograin structures and electrical characte ristics of sputtered indium tin oxide (ITO) films was investigated. Mi crograin structures were observed by a high resolution scanning electr on microscope. Electrical characteristics were evaluated by four point probe resistance measurement and Hall effect measurement. Low resisti vity ITO films had domain structures. One domain consisted of many spu tter grains having the same orientation. The resistivity decreased wit h increasing domain size. The domain boundary might cause scattering f or conduction electrons. Therefore, larger domain ITO films had a high er Hall mobility. The minimum resistivity was 1.8 X 10(-4) OMEGA Cm, d epo-sited at a sputtering voltage of -250 V and a 250-degrees-C deposi tion temperature. The electron conduction mechanism in domain structur ed ITO films was taken into consideration.