Enhanced stability of Ni monosilicide on MOSFETs poly-Si gate stack
Lee, Pooi See
Pey, Kin Leong
Chi, Dong Zhi
Dai, J. Y.
Date of Issue2002
School of Materials Science and Engineering
The formation and stability of Ni(Pt)Si on metal oxide semiconductor field effect transistor (MOSFETs) polycrystalline-Si (poly-Si) gate stack was investigated. Poly-Si and partial amorphous Si (a-Si) structures were grown using LPCVD and RTCVD techniques. For pure Ni silicidation, nucleation of NiSi2 was found at 700°C, which is slightly lower than that on monocrystalline Si (about 750°C). With Pt addition, Ni(Pt)Si was found up to 800°C, implying the important role of Gibbs free energy changes in enhancing the monosilicide stability. The extent of layer inversion of Ni(Pt)Si on RTCVD-Si is less than that on LPCVD-Si and thus results in a slower sheet resistance degradation.
© 2002 Elsevier B.V.