Arsenic shallow junction using titanium silicide as a diffusion source

n+/p shallow junctions were obtained by implantation of 1x1016 As+ / cm2 at 25 keV into a 57 nm thick TiSi2 layer and by a subsequent diffusion into silicon. The drive-in was performed using either a rapid thermal annealing system or a traditional furnace. Before the diffusion process the damage introduced by the arsenic implantation into TiSi2 was thermally annealed. This step was necessary to improve the silicide resistivity. Carrier concentration and mobility profiles were obtained by Van der Pauw measurements. Arsenic concentrations of 1x1020 cm-3, activated diffused amounts per unit area of 1x1015 cm-2 and mobilities of 80 cm2/(V,s) were achieved with junction depths lower than 50 nm. The segregation coefficient at the TiSi2/Si interface was obtained for the total amount of diffused arsenic atoms and for the substitutional fraction by Rutherford backscattering analysis in combination with channeling technique.