Formation of NiSi-silicided p(+)n shallow junctions using implant-through-silicide and low-temperature furnace annealing

Abstract

NiSi-silicided p(+)n shallow junctions are fabricated using BF2+ implantation into/through thin NiSi silicide layer (implant-through-silicide technology) followed by low-temperature furnace annealing (from 550 to 800degreesC). The NiSi film agglomerates following a thermal annealing at 600degreesC and may result in the formation of discontinuous islands at a higher temperature. The incorporation of fluorine atoms in the NiSi film can retard the formation of film agglomeration and thus improving the film's thermal stability. The forward ideality factor of about 1.02 and the reverse current density of about 1 nA/cm(2) can be attained for the NiSi (310 Angstrom)/p(+)n junctions fabricated by BF2+ implantation at 35 keV to a dose of 5x10(15) cm(-2) followed by a 650degreesC thermal annealing; the junction formed is about 60 nm measured from the NiSi/Si interface. Activation energy measurement indicates that the reverse bias junction currents are dominated by the diffusion current, indicating that most of the implanted damages can be recovered after annealing at a temperature as low as 650degreesC. (C) 2003 The Electrochemical Society.