Electrical Properties and Structures of TiAl Alloy Thin Films Prepared by Sputtering from Composite Targets

Ti-Al alloy films were deposited on glass substratesby D.C. sputtering from the Ti-Al composite targets, which have the various aluminium area ratios to obtain different film compositions. Resistivity, temperature coefficient of resistance (TCR), Hall coefficient and structures of films deposited at the different substrate temperatures have bden investigated. The values of resistivity, TCR and Hall coefficient varied with the Al weight ％ in the films and the substrate temperatures. Their curves plotted as a function of the Al weight ％ indicated the same tendency even if the films were deposited at different temperatures. However, the influence of the substrate temperature on the signs of the TCR and Hall coefficient was evidently observed in the films with the aluminium weight of 65％. The films sputtered from the composite targets with the aluminium area ratios 49％ on the substrate at 200℃ and 400℃ have the resistivity of about 260 μΩ-cm and TCR of -130 ppm/℃. These have suitablecharacteristics as a resistor for practical use. The structures of deposited films have been investigated by X-ray and electron transmiting diffraction analysis, and some information, which was available for the interpretation of the electrical properties of the alloy films