Agglomeration Resistant Self-Aligned Silicide Process Using N 2 Implantation into TiSi 2

An agglomeration resistant self-aligned silicide (SALICIDE) process using N 2 implantation into TiSi 2 films has been developed. The film morphology and the film sheet resistance after high-temperature annealing in an Ar ambient were evaluated as a function of implanted nitrogen doses. High implantation doses of 5×10 16 cm -2 or more realized the completely flat film after the annealing; however there is an optimum dose of approximately 1×10 16 cm -2 for maintaining the film sheet resistance at its minimum value. This phenomenon could be explained by the fact that the main composition of the film was changed from TiSi 2 (C54) to TiN with a 5×10 16 cm -2 or more nitrogen implantation and that the TiN film contains Si crystals. A successful application of this technique to a 0.8 µm n-MOS transistor is also presented.