Indium tin oxide thin films deposited by RF-magnetron sputtering for organic electro-luminescence devices

Abstract

Indium tin oxide (ITO) thin films for organic electro-luminescence (EL) devices were deposited by radio frequency (RF) magnetron sputtering at low temperature. Process parameters such as working pressure, RF power, deposition time, Ar flow rate and target-to-substrate distance are tuned to optimize ITO properties. Transmittance is strongly dependent on the film thickness: Overall transmittance was slightly decreased with the thickness while local fluctuations of a sinusoidal shape occurred. Transmittance of the crystalline films is generally lower than that of amorphous films due to high scattering on the rough surface of the crystalline film. However, sheet resistance was relatively insensitive to crystallinity and orientation of the film. An ITO thin film deposited under the condition of 7 mTorr, 100W and 6minutes had a sheet resistance of similar to22 Ohm/sq., transmittance of 89% and the rms (root-mean-square) value of 0.46 nm.