Influence of the anneal conditions on arsenic activation during solid-phase epitaxial regrowth

We investigate the influence of the initial stage of the thermal treatment during solid-phase epitaxial regrowth (SPER) on the electrical activation level of arsenic in self-amorphized silicon, both with respect to heating ramp-up rates and the use of low-temperature preanneals. Enhancement of the electrically-active arsenic concentration by 14% is observed for activation with the fastest ramp-up rates (430°C∕s) compared to the slowest ones (36°C∕s). Around 50% of the 1015at∕cm2, arsenic implant at 5 keV is found to be nonsubstitutional and this fraction reaches even 99% for dose 3×1015at∕cm2. Arsenic clustering in silicon amorphous phase during SPER is recognized to play an important role in the decrease of the active dose.