Silicides have been widely used as contacts in an ultra-large scale integration (ULSI) technology to reduce the contact and series resistance of the device [1]. Nickel silicide is one of the leading candidates for sub-90 ULSI shallow junction metallization due to its low resistively, good diffusion barrier property, low process temperature and low Si consumption [2] .In this work we describe a novel method to form NiSi contacts using electroless plating of Nickel on Pd activated silica-organic monolayer on Si. Electroless plating on Pd activated self assembled monolayer (SAM) allows uniform deposition of very thin, less than 30 nm, of Ni or Ni alloys. We propose electroless deposition of Ni alloys directly on Si modified by SAM for a better adhesion and uniformity of the layers. SAM provides a method for creating surface with controllable chemical functionality. Amino terminated group (-NH2) silane has been used for Si functionalization in this case study. After silanization process formation of NiP and NiPW thin films by electroless deposition on SAM/p-Si (100) has been studied. The samples were annealed at temperatures of up to 400-500oC for up to 1 hour forming a thin silicide layer. The material and electrical properties of the silicides were characterized using SEM analysis, XRD, XPS profiling and EBSD. XRD measurement of the sample confirmed the presence of NiSi phase after annealing at 400-500oC for 1 h in vacuum (~ 10-6 Torr).
List of References
[1] J.P. Gambino, E.G. Colgan, Materials Chemistry and Physics, 52 (1998), pp.99-146.
[2] T.Morimoto, T.Ohguro, H.S. Momose, T.Iinuma, I.Kunishima, K.Suguro, I.Katakabe, H.Nakajima, M.Tsuchiaki, M.Ohno, Y.Katsumata, H.Iwai, IEEE Tran.Electron.Dev,42(1995), 915-922.
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