Effect of substrate temperature on the electrical and optical properties of dc reactive magnetron sputtered indium oxide films

Thin films of indium oxide (In2O3) were deposited onto glass substrates held at temperatures in the range 373-673 K using the de reactive magnetron sputtering technique. The dependence of electrical and optical properties of the films on the substrate temperature was studied. The films formed at 373 K were amorphous, whereas those prepared at greater than or equal to 473 K were polycrystalline in nature. The electrical resistivity of the films decreased from 2.4 x 10(-2) to 1.3 x 10(-3) Omega cm and the Hall mobility increased from 2.5 to 18 cm(2) V-1 s(-1) with the increase of substrate temperature from 373 to 673 K, respectively due to improvement in the crystallinity of the films. The temperature dependence of the Hall mobility revealed that the grain boundary scattering of the charge carriers predominated in the films. The optical transmittance (at lambda = 600 nm) increased from 68% to 85% and the optical band gap increased from 3.64 to 3.78 eV with the increase of substrate temperature from 373 to 673 K, respectively. (C) 2000 Elsevier Science B.V. All rights reserved.