Migration of ion-implanted krypton in silicon during anneal

Helium backscattering and 85Kr radiotracer techniques have been used to study the movement of implanted krypton in silicon during subsequent vacuum anneal at 650, 750, and 900°C. Doses from 5×1013 to 1×1016 cm−2 and implantation energies of 25, 50, 100, and 500 keV were used in the study. Within the dose range 1014–1015 ions cm−2, a large outward migration of 85Kr is observed during the anneal and, except in the 500-keV case, most of the Kr escapes from the target. At still higher implant doses (i.e.,≳2×1015 cm−2), this outward migration is reduced, and no loss of 85Kr is detected except at 25 keV. In all cases, at implant doses ≲1014 cm−2, no migration or loss of Kr is observed. Helium backscattering measurements on the 500-keV implants indicate that in the dose range 1014–1015 cm−2 reordering of the amorphous silicon formed by the implantation is associated with some outward Kr movement.

Migration of ion-implanted krypton in silicon during anneal Journal Articles