Silicide formation for Ni and Pd bilayers on Si(100) substrates

摘要

The silicide formation for Ni/Pd and Pd/Ni bilayers on Si(100) substrates was investigated.X-ray diffraction and photoelectron spectroscopy (XPS) depth profiling have been applied to study the phase formation of the silicide.We found that with addition of Pd into Ni/Si,uniform layer of termary Ni_(1-x)Pd_xSi layer formed and kept stable for a wide temperature range.The lattice parameter of Ni_(1-x)Pd_xSi as a function of Pd addition was calculated.The nucleation temperature of NiSi_2 was delayed due to the addition of Pd.The higher the Pd addition,the larger the increase in NiSi_2 nucleation temperature.We also studied the effect on the addition of Ni to the Pd/Si reaction.For pure Pd/Si reaction PdSi nucleated from Pd_2Si at 750degC or above.For Ni/Pd/Si reation,Pd_2Si phenomena were explained by classic nucleation theory taking into account the effect of mixing entropy effect.