  UV laser annealing (UV-LA) enables surface-localized high-temperature thermal
processing to form abrupt junctions in emerging monolithically stacked devices,
where the applicable thermal budget is restricted. In this work, UV-LA is
performed to regrow a silicon-on-insulator wafer partially amorphized by
arsenic ion implantation as well as to activate the dopants. In a microsecond
scale ( 10^-6 s to 10^-5 s) UV-LA process, monocrystalline solid phase
recrystallization and dopant activation without junction deepening are
evidenced, thus opening various applications in low thermal budget integration
flows. However, some concerns remain. First, the surface morphology is degraded
after the regrowth, possibly because of the non-perfect uniformity of the used
laser beam and/or the formation of defects near the surface involving the
excess dopants. Second, many of the dopants are inactive and seem to form deep
levels in the Si band gap, suggesting a further optimization of the ion
implantation condition to manage the initial crystal damage and the heating
profile to better accommodate the dopants into the substitutional sites.
