Effects of N-induced heterogeneous nucleation and growth of cavities at the CoSi2/polycrystalline-silicon interface

N-induced cavity nucleation at the CoSi2/Si interface has been investigated for different doses and its influence on improving the thermal stability of the silicide layer up to 1075 degreesC has been detailed. The N-implant energy and doses have been chosen in such a way that the projected range (R-p) was near the interface and the underlying polycrystalline silicon substrate was completely amorphized. After a thermal treatment of 975 degreesC, it has been found that the cavity density depends on the dose, but the cavity size is dose independent. The cavity density should be enough to saturate the silicide grain boundaries but not so high to neglect ripening and coalescence. A density of 2.5x10(10) cavities/cm(2) has been measured at a nitrogen dose of 7x10(15)/cm(2) corresponding to a partial saturation of the silicide grain boundaries and to the higher stability gain (150 degreesC). (C) 2002 American Institute of Physics.