A novel clean Ti salicide process using grooved gate structure

It is demonstrated that dry etching and Ar sputtering for Si surface cleani ng cause phase transition failures of TiSi2 and degradation of the resistiv ity. We propose a Ti self-aligned-silicide (salicide) process using a groov ed gate structure. In this technique, poly-Si is patterned by an oxide mask . The ox:ide layer protects the gate surface from contamination by dry etch ing for sidewall formation. Before Ti deposition, the poly-Si surface is no t sputtered by Ar to clean the surface. As a result, TiSi2 agglomeration wa s suppressed drastically in comparison with the conventional gate structure .