LOW-TEMPERATURE PROCESSING OF SHALLOW JUNCTIONS USING EPITAXIAL AND POLYCRYSTALLINE COSI2

Cobalt disilicide is grown epitaxially on (100) Si from a 15 nm Co/2 nm Ti bilayer by rapid thermal annealing (RTA) at 900 degrees C. Polycrystalline CoSi2 is grown on (100) Si using a 15 nm Co layer and the same annealing condition. Silicide/p(+)-Si/n-Si diodes are made using the silicide as dopant source: B-11(+) ions are implanted at 3.5-7.5 kV and activated by RTA at 600-900 degrees C. Shallow junctions with total junction depth (silicide plus p(+) region) measured by high-resolution secondary ion mass spectroscopy of 100 nm are fabricated. Areal leakage current densities of 13 nA/cm(2) and 2 nA/cm(2) at a reverse bias of-SV are obtained for the epitaxial silicide and polycrystalline silicide junctions, respectively, after 700 degrees C post-implant annealing.