EFFECTS OF AL3TA TAN BILAYERED DIFFUSION-BARRIERS IN THE AL/SI CONTACT SYSTEMS/

A thermally stable contact system of Al/Al3Ta/TaN/Si, which tolerates post-metallization annealing even at 600 degrees C for 1 h, was succes sfully prepared by achieving a state of chemical pseudo-equilibrium at the interface of Al/Al3Ta and that of Al3Ta/TaN. No solid-phase react ions took place at these interfaces due to the realization of minimum free energy states. The thermal stability of the interfaces in the con tact system was discussed from the point of view of the solid-phase re action of thin films. It was also revealed by X-ray diffraction analys is that the absence of structural change due to grain growth in both t he TaN and Al3Ta layers by annealing is effective for the total stabil ity of the contact system. We have been successfully able to demonstra te the validity of realizing the chemical pseudo-equilibrium interface s for preparing thermally stable contact systems.