Low temperature growth of high quality indium tin oxide thin films by ultraviolet-assisted pulsed laser deposition

Indium tin oxide (ITO) films were grown on (100) Si and Coming glass substrates by an in situ ultraviolet-assisted pulsed laser deposition (UVPLD) technique. The most important deposition parameter for the growth of high transparent and conductive ITO films was found to be the oxygen pressure used during the deposition. Films grown under low oxygen pressure were brown and exhibited low optical transmittance and high resistivity. For a target-substrate distance of 10.5 cm, which ensured an uniform film across 2.5 cm, the optimum oxygen pressure to obtain the lowest electrical resistivity was found to be around 10 mTorr. For higher oxygen pressures, the optical transmittance was a little bit higher but a significant increase of the electrical resistivity was noticed. X-ray photoelectron spectroscopy showed that ITO films grown in the 5-20 mTorr range were fully oxidized, without any measurable metallic content. Films grown at room temperature were amorphous regardless of the oxygen pressure used.