Abstract

Effect of substrate temperature on whisker growth of electron-beam-evaporated indium tin oxide

Author(s): S.N.Alamri

Thin films of indiumtin oxide (ITO) were deposited on soda-lime glass with the electron beam technique at substrate temperatures between 50oC and 300oC. Properties that were characterised include structure, surface morphology, resistivity,mobility, transmittance, reflectance, and optical band gap. Structural characterization was performed using scanning electron microscopy andX-ray diffraction. Elevating the substrate temperatures from 50oC to 300oC, increased the thickness of ITOfilmsmore than three times by increasing the grain size. The microstructure of the ITO film changed from amorphous to polycrystalline as a function of increasing substrate temperature. The transmittance of the filmincreased, despite the increasing thickness, and the reflectance was reduced. The optical band gap, Eg, increased from3.8 eV for the filmdeposited at 150oC to 3.94 eV for the film deposited at 300oC. The resistivities and mobilities of the fabricated films decreased and increased, respectively, up to 2500C and then deteriorated at 3000C, which could be due to the formation of the observed whiskers.