Various Properties of sputtered Ta_xAl_t-x films

Films of TaxAlt-x have been prepared by diode sputtering from a target consisting of an Al mask placed on the face of a Ta target. The Ta target was 8 inches in diameter while the Al mask was 0.125 inches thick and machined with a grid-like shape. Films were deposited for a range of pressure, at a power of 300 watts, onto oxidized 100 mm diameter Si substrates that were placed on a planetary table beneath the target. The results show that such films oxidize at temperatures in the 300 to 600 °C range via a diffusion-controlled process with an activation energy of 0.98 eV. Such films are substantially more oxidation-resistant than either α or β tantalum.