Title :
A novel process to form cobalt silicided p/sup +/ poly-Si gates by BF/sub 2//sup +/ implantation into bilayered CoSi/a-Si films and subsequent anneal
Author :
Lai, W.K. ; Liu, H.W. ; Juang, M.H. ; Chen, N.C. ; Cheng, H.C.
Author_Institution :
Dept. of Electron. Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan
fDate :
7/1/1998 12:00:00 AM
Abstract :
A novel process that implants BF/sub 2//sup +/ ions into thin bilayered CoSi/a-Si films has been shown to form cobalt silicided p/sup +/ poly-Si gates with excellent gate oxide integrity and very small flatband shift. The effects of not only using the CoSi layer as an implantation barrier but also keeping the a-Si underlayer during the initial silicide formation both significantly suppress the boron penetration through thin gate oxide.
Keywords :
amorphous semiconductors; annealing; boron compounds; chemical interdiffusion; cobalt compounds; diffusion barriers; elemental semiconductors; ion implantation; semiconductor-metal boundaries; silicon; BF/sub 2//sup +/ implantation; CoSi-Si:BF/sub 2/; annealing; bilayered CoSi/a-Si films; boron penetration; cobalt silicided p/sup +/ poly-Si gates; gate oxide integrity; implantation barrier; silicide formation; small flatband shift; thin gate oxide; Boron; Cobalt; Hot carriers; Implants; Impurities; Leakage current; MOSFET circuits; Rapid thermal annealing; Silicides; Threshold voltage;
Journal_Title :
Electron Device Letters, IEEE
