The process window of a-Si/Ti bilayer metallization for an oxidation-resistant and self-aligned TiSi/sub 2/ process

Abstract

The dependences of both oxidation-resistant and self-aligned silicidation properties on the thicknesses of top amorphous-Si (a-Si) and Ti metal in an a-Si/Ti bilayer process are presented. It is shown that a thin silicide layer formed during the reaction between a-Si and Ti films becomes a stable oxidation and nitridation barrier for oxygen-and nitrogen-related impurities. Moreover, the formation sequence of the silicide phase depends on not only the annealing temperature but also the thickness of Ti film. In addition, the preferential orientation of the silicide phase after annealing at high temperature also shows a strong dependence of the thickness of Ti film, which is attributed to the difference of the grain size in the polycrystalline silicide film. The allowed process window for the a-Si thickness can be determined experimentally and a reproducible and homogeneous self-aligned TiSiz film can be easily obtained by using the a-Si/Ti bilayer process in SALI-CIDE applications despite of high-level contaminations of oxygen impurities in both the as-deposited Ti film and the annealing ambient.

Epitaxial C 49 ‐ TiSi2 Formation on (100)Si Substrate Using TiN x and Its Electrical Characteristics as a Shallow Contact Metallization

“…Electrical properties of TiN/TiSi2 metallization contact-The junction leakage current (Jleak) ofTiN/TiSi2 contacted junctions at the reverse viased at 5 V was measured and the results are shown in Fig. 19, in which the 20 30 TiN/TiSi2 was formed from the TiN/pure-Ti (control wafer) and the TiNX. The control wafer shows more severe dependence of the 1Ieak on the annealing temperature than the TiN1 contacted junction.…”