Effects of thermal processes after silicidation on the performanceof TiSi2/polysilicon gate device

The effects of thermal processes after silicidation on the gate depletion, threshold voltage (V_th) shift, drive current, and sheet resistance of TiSi₂/polysilicon (Ti-polycide) gate devices are evaluated. The dopant depletion of the polysilicon film, which is known to increase the V_th and to degrade the drive-current, increases with increasing temperature of the post-thermal process. However, the V_th roll-off characteristic in nMOSFETs is enhanced with increasing temperature. Furthermore, the drive-current is significantly degraded by the gate reoxidation process. The sheet resistance of the Ti-polycide gate increases with gate reoxidation as well as with increased post-thermal processes