Oxygen annealing for deuterium-doped indium tin oxide thin films

Deuterium-doped indium tin oxide films, fabricated by dc plasma deposition in sputter gas consisting of deuterium and argon, were annealed at 300 degrees C for 40 min in flowing oxygen gas by using tubular gold image furnace. On oxygen annealing, the optical transparency of the film deposited at the gas pressure ratio of deuterium to argon of 3.6% increased from approximate to 30 to 60% at the wavelength of 600 nm, although that of the films deposited at the ratios of 1 and 1.5% slightly decreased from 88 to 80% and from 85 to 77%, respectively. The resistivity of the films at room temperature, ranged from 2 x 10(-4) to 1.4 x 10(-3) Omega cm corresponding to the gas pressure ratio from 1 to 3.6%, was almost the same before and after the annealing for each film. A change in morphology toward a smoother surface by the oxygen annealing was apparent especially for the film with the gas pressure ratio of 3.6%. Agglomeration of randomly oriented grains with diameters of < 100-200 nm observed before the annealing disappeared on annealing. A smoother surface is responsible for higher transparency of the annealed films that contained densely populated hydroxyl bond before the annealing. [GRAPHICS] Oxygen annealing at 300 degrees C enlarged the optical transmittance (left panel) but decreased the population of hydrogen-bonded oxygen (right panel) of the indium tin oxide thin film fabricated by dc plasma deposition in sputter gas containing deuterium of 3.6%. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim