PROPERTIES OF TITANIUM LAYERS DEPOSITED BY COLLIMATION SPUTTERING

Properties of titanium (Ti) films deposited by collimation sputtering are studied. In Ti film deposition at the 0.5 mum ohmic contact area (aspect ratio: 3.6), conformality, y/x, defined by the thickness on the bottom, y, to the surface, x, is as low as 6% in conventional sputtering. However, it can be improved to 21% by employing collimation sputtering. Strongly (002)-oriented Ti film is deposited by conventional sputtering. Weakly (002)- and (011)-oriented grains, however, are grown in collimation film. with annealing at 650-degrees-C of the Ti film deposited on Si, different solid phase silicidation reactions occur at the Ti/Si. That is, metastable C49 TiSi2 grains are grown in conventional Ti film at 625-650-degrees-C. In collimation film, C54 TiSi2 grains are preferentially grown at this temperature. This result indicates the formation of a stable C54 TiSi2 layer with lower sheet resistance.