Determination of W-Ti/Al thin-film interaction by sheet resistance measurement

The interaction between an aluminum film and a W-Ti film during annealing was monitored by sheet resistance measurements. The sheet resistance of this thin-film stack is mainly detd. by the thickness and resistivity of the aluminum film. During annealing, interaction takes place between the two films, resulting in an increase in sheet resistance of the thin-film stack. This increase in sheet resistance can be caused by an increase in aluminum resistivity, due to the dissoln. of tungsten and titanium in the aluminum film, and by a decrease in aluminum thickness, owing to the formation of aluminum-tungsten and aluminum-titanium compds. By measuring not only the sheet resistance but also the temp. deriv. of the sheet resistance, the resistivity and the thickness of the aluminum film can be obtained sep. The large increase in sheet resistance during the first stage of the thin-film interaction is mainly caused by the large resistivity increase of the aluminu