Effects of hydrogen gas on properties of tin-doped indium oxide films deposited by radio frequency magnetron sputtering method

Tin-doped indium oxide (ITO) films were deposited at similar to 70 degrees C of substrate temperature by radio frequency magnetron sputtering method using an In2O3-10% SnO2 target. The effect of hydrogen gas ratio [H-2/(H-2+Ar)] on the electrical, optical and mechanical properties was investigated. With increasing the amount of hydrogen gas, the resistivity of the samples showed the lowest value of 3.5 x 10(-4) Omega center dot cm at the range of 0.8-1.7% of hydrogen gas ratio, while the resistivity increases over than 2.5% of hydrogen gas ratio. Hall effect measurements explained that carrier concentration and its mobility are strongly related with the resistivity of ITO films. The supplement of hydrogen gas also reduced the residual stress of ITO films up to the stress level of 110 Wa. The surface roughness and the crystallinity of the samples were investigated by using atomic force microscopy and x-ray diffraction, respectively. (C) 2007 Elsevier B.V. All rights reserved.