Properties of ITO thin films deposited by RF magnetron sputtering at elevated substrate temperature

Indium tin oxide films have been deposited by RF magnetron sputtering techn ique. Discharge power density has been varied from 0.36 to 2 W cm(-2) and p ure argon or argon/oxygen mixture have been utilised as sputtering gas. Sub strate temperature has been kept at 250 degrees C for all the samples. Film 's crystallisation behaviour has been investigated as a function of RF powe r density. XRD analysis revealed a change in preferential orientation of po lycrystalline crystalline structure from (222) to (400) plane with the incr ease in RF power. Crystallite size was found to increase with the RF power. EPMA analysis revealed a higher O/In ratio in the [111] oriented samples t han in the [100] oriented ones. In/Sn ratio, evaluated by ICP analysis, dec reased with the increase in RF power and with the change of sputtering gas from pure Ar to Ar/O-2 mixture. Optical band gap was found continuously dec reasing with the increase in RF power. Hall effect measurement showed the i nfluence of high deposition power on the electron mobility degradation. A v ery low electrical resistivity of 8.6 x 10(-5) Ohm cm(-1) was achieved duri ng this investigation. A close correlation between the preferential orienta tion and film properties has been pointed out. (C) 2000 Elsevier Science S. A. All rights reserved.