Improved NiSi salicide process using presilicide N2+ implant for MOSFETs
Lee, Pooi See
Pey, Kin Leong
Wee, A. T. S.
Date of Issue2000
School of Materials Science and Engineering
An improved Ni salicide process has been developed by incorporating nitrogen (N+ 2 ) implant prior to Ni deposition to widen the salicide processing temperature window. Salicided poly-Si gate and active regions of different linewidths show improved thermal stability with low sheet resistance up to a salicidation temperature of 700 and 750 °C, respectively. Nitrogen was found to be confined within the NiSi layer and reduced agglomeration of the silicide. Phase transformation to the undesirable high resistivity NiSi2 phase was delayed, likely due to a change in the interfacial energy. The electrical results of N+2 implanted Ni-salicided PMOSFETs show higher drive current and lower junction leakage as compared to devices with no N+2 implant.
IEEE electron device letters
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