Electrical, and compositional properties of TaSi2 films

Tantalum silicide (TaSi2) thin films were sputter deposited on p- and n-type silicon substrates using ultrapure TaSi2 targets. The TaSi2/Si samples were annealed in nitrogen or forming gas or oxygen containing steam at temperatures in the range of 400-900degreesC. The sheet resistances of TaSi2/Si were measured by four-point, probe before. and after anneal. The structure of these films was investigated using x-ray diffraction (XRD) methods. It has been found that the sheet resistance decreases with the increase in annealing temperature and also with the increase in film thickness. X-ray diffraction patterns show changes in the morphological structure of the films. Oxidation characteristics of the films have been investigated in the temperature range of 400-900degreesC in oxygen containing steam ambient. The oxidation time ranged from 0.5 to 1.5 h. No oxide formation of the tantalum silicide films was observed in this investigation. This has been attributed, to the high purity of TaSi2 sputter targets used in the preparation of the films.