Thermal stability of nickel silicide on silicon on insulator (SOI) material

The growth of Ni monosilicide layers on As doped silicon on insulator (SOI) substrates has been studied in the temperature range between 450 and 950degreesC. Sheet resistance measurements (R-s) and X-ray diffraction (XRD) analyses have shown a remarkable improvement of the thermal stability mainly due to the use of spike annealing processes. TEM analyses have indicated that NiSi film maintains a columnar structure and a flat interface with the substrate as the temperature increases up to 900degreesC. Above this temperature, morphological and structural changes like agglomeration phenomena, hole formation and nucleation of the silicon rich phase, have caused an abrupt increase of the sheet resistance of the layer.