Gallium distribution and electrical activation in Ga+-implanted Si

Gallium distribution profiles in Ga⁺-implanted silicon have been measured by secondary ion mass spectrometry (SIMS) and differential Hall effect methods. The previously reported penetrating tails are not observed for as-implanted samples. The redistribution of Ga during annealing is affected by ion damage and effects due to recrystallization of the amorphous layer. Electrical carrier profiles indicate that carrier concentration higher than the usual Ga solid solubility can be achieved in Ga-implanted Si recrystallized at 600‡C. However, this large acceptor concentration diminishes after higher temperature annealing. For 900‡C anneals, the carrier concentration is limited by the Ga solid solubility and some compensation due to unannealed ion damage. Work Supported by the Joint Service Electronics Program (U.S. Army, U.S. Navy, U.S. Air Force) under Contracts DAAB-07-72-C-0259 and DAAG-16-78-C-0016, and by the National Science Foundation under Grants DMR-77-22228, DMR-76-01058, and CHE-76-03694.