Room-temperature growth of crystalline indium tin oxide films on glass using low-energy oxygen-ion-beam assisted deposition

One of the long-standing problems to improve the resolution of organic electroluminescence devices has been related to the fabrication of very smooth, high-quality indium tin oxide (ITO) layers at room temperature. It seems that this problem could be solved by low-energy oxygen-ion-beam assisted electron-beam evaporation of ITO bulk material in vacuum. The oxygen ions were produced in an electron cyclotron resonance source with energies varied between 50 and 1000 eV. The growth rate changes from 0.04 to 0.23 nm/s. The structural, electrical and optical properties were characterized by x-ray diffraction, Rutherford backscattering, atomic force microscopy, Hall-effect and optical transmittance measurements. Crystalline structure, which depends only on the thickness of the deposited ITO films, can be easily obtained at room temperature. A very smooth surface of only 0.6 nm roughness (root mean square), almost one order smaller than that prepared by other methods, low resistivity of 7.0x10(-4) Omega cm, high carrier density of 6.1x10(20) cm(-3), and high optical transmittance of 85% at wavelength 550 nm (including the glass substrate) could be repeatedly achieved at room temperature. (C) 2003 American Institute of Physics.