  Three-dimensional (3D) CMOS technology encourages the use of UV laser
annealing (UV-LA) because the shallow absorption of UV light into materials and
the process timescale typically from nanoseconds (ns) to microseconds (us)
strongly limit the vertical heat diffusion. In this work, us UV-LA solid phase
epitaxial regrowth (SPER) demonstrated an active carrier concentration
surpassing 1 x 10^21 at./cm^-3 in an arsenic ion-implanted silicon-on-insulator
substrate. After the subsequent ns UV-LA known for improving CMOS interconnect,
only a slight (about 5%) sheet resistance increase was observed. The results
open a possibility to integrate UV-LA at different stages of 3D-stacked CMOS.
