Refractory metal silicide/N+ polysilicon in CMOS/SOS

Dual layer gate structure of refractory metal silicides, namely tantalum silicide and molybdenum silicide over the N⁺doped polysilicon were investigated. The processing technique related to deposition of the metals, silicide film anealing, oxidation, and etching of the films will be reported in this paper. Established techniques were applied in the CMOS/SOS N⁺gate process. Excellent transistor characteristics of 2um gate length were obtained, and circuits with 4um gate dimensions had speed advantages over those fabricated with polysilicon. The final sheet resistance of this composite structure is approximately 4ohms/.