TECHNOLOGICAL ASPECTS OF EPITAXIAL COSI2, LAYERS FOR CMOS

The use of consecutively sputtered Ti/Co layers for the silicidation of Si implanted with 2 X 10(15) As or B/cm(2) and for the silicidation of polycrystalline Si has been investigated. It has been observed that the silicidation reaction is slowed down by the presence of the Ti layer, which acts as a diffusion barrier. The use of a Ti/Co bilayer leads to the growth of epitaxial CoSi2 layers on implanted silicon with very smooth CoSi2/Si interfaces and an excellent thermal stability. In addition, the silicide formation on poly-Si gate lines has been studied. It has been found that amorphisation of poly-Si prior to metal deposition prevents the lateral overgrowth of the silicide on the oxide spacers during silicidation.