Title :
Improved NiSi salicide process using presilicide N/sub 2//sup +/ implant for MOSFETs
Author :
Lee, P.S. ; Pey, K.L. ; Mangelinck, D. ; Ding, J. ; Wee, A.T.S. ; Chan, L.
Author_Institution :
Dept. of Mater. Sci., Nat. Univ. of Singapore, Singapore
Abstract :
An improved Ni salicide process has been developed by incorporating nitrogen (N/sub 2//sup +/) 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/spl deg/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 NiSi/sub 2/ phase was delayed, likely due to a change in the interfacial energy. The electrical results of N/sub 2//sup +/ implanted Ni-salicided PMOSFETs show higher drive current and lower junction leakage as compared to devices with no N/sub 2//sup +/ implant.
Keywords :
MOSFET; nickel alloys; silicon alloys; surface energy; thermal stability; 700 to 750 C; MOSFETs; NiSi; NiSi salicide process; higher drive current; interfacial energy; low sheet resistance; lower junction leakage; presilicide N/sub 2//sup +/ implant; thermal stability; CMOS technology; Conductivity; Delay; Electric resistance; Implants; MOSFETs; Nitrogen; Silicides; Temperature; Thermal resistance;
Journal_Title :
Electron Device Letters, IEEE
