INITIAL SILICIDE FORMATION PROCESS OF SINGLE ORIENTED (002)HF FILM ONSI AND ITS DIFFUSION BARRIER PROPERTY

We have investigated the initial silicide formation process of the sin gle oriented (002) Hf fim on (001) Si and compared it with that of the polycrystalline Hf film. From the results of Xray diffraction analysi s, we found that the first nucleation phase of Hf silicide is the mult iphase silicides of Hf3Si2 containing a small amount of Hf5Si3 and the silicidation temperature is 420 degrees C which is much lower than th e values reported so far. The chemical nature of the silicide phase fo rmed was evaluated by means of Auger electron spectroscopy ans X-ray p hotoelectron spectroscopy. It is seen from these analyses that the che mical bonding state is the same as that of Hf3Si2, which has the lowes t contact resistivity. Furthermore, it is also revealed that the diffu sion barrier property of the single oriented (002) Hf film is superior to that of the polycrystalline Hf film, in which a rapid out-diffusio n of Si occurs.