We have investigated sputter-deposited TaSi(x), TaSi(x)N(y), and TaSi(
x)N(y)/TaSi(x) thin films as the diffusion barrier between aluminum an
d silicon. The sheet resistance of the films was measured. The structu
re of the films was determined by transmission electron micrographs an
d X-ray diffraction patterns. A thermal stability study was performed
by measuring the reverse bias leakage current on n +-p Si junction dio
des and the specific contact resistance on n + Si after various sinter
ing conditions. We found that the TaSi(x) film in the TaSi(x)N(y)/TaSi
(x) bilayer structure showed the advantage of low sheet resistance and
low specific contact resistance. The existence of TaSi(x)N(y) in the
bilayer structure gives a high resistance to the Al-Si interdiffusion.
The bilayer structure is thermally stable up to 530-degrees-C.