engleski

Thermal Stability of Al-W Amorphous Thin Films

The Al-W thin films, with composition in the range from Al80W20 to Al66W34, were prepared by simultaneous d.c. sputtering of both aluminium and pure tungsten (on glass, fused quartz, alumina or sapphire as substrates) in a multiple source sputtering apparatus. The prepared films are investigating by XRD using a Philips PW 1820 vertical goniometer with monochromatized Cu Ka radiation and by measuring electrical resistivity. Thin films were found completely amorphous and the negative temperature coefficient of the electrical resistivity confirmed the amorphous state. Using annealing procedure it was found that amorphous films did not crystallize up to 4000C. However, at 5000C and higher temperatures, the W2Si phase and some unidentified lines were detected on XRD patterns on films deposited on quartz substrate, showing the reaction of films with substrate. As-deposited films on alumina substrates were also amorphous and stable up to 5000C. Investigation of the crystallization behaviour of the amorphous films, on temperatures between 5300C and 6900C, are now in progress and the preliminary results will be reported at the Conference.

Al-W alloys; Thin Films

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