TECHNOLOGICAL ASPECTS OF EPITAXIAL COSI2, LAYERS FOR CMOS

The use of consecutively sputtered Ti/Co layers for the silicidation o f 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 la yer, which acts as a diffusion barrier. The use of a Ti/Co bilayer lea ds to the growth of epitaxial CoSi2 layers on implanted silicon with v ery smooth CoSi2/Si interfaces and an excellent thermal stability. In addition, the silicide formation on poly-Si gate lines has been studie d. It has been found that amorphisation of poly-Si prior to metal depo sition prevents the lateral overgrowth of the silicide on the oxide sp acers during silicidation.