An investigation was made of the room-temperature migration of ion-generated defects in crystalline samples. The defects were injected into the bulk of a pure epitaxial layer via 40keV Si implantation and were monitored by using a pre-existing defect distribution that had been produced, as a marker, by means of high-energy He implantation. The depth of this marker defect layer was fixed by choosing an He implantation energy of between 1 and 3MeV. The use of spreading resistance measurements showed that the injected defects produced a partial annihilation of the pre-existing damage. The magnitude of this annihilation depended strongly upon the depth of the defective marker. It was very large when the marker was confined to within 5 of the surface, and was negligible when it lay below a depth of about 10. Detailed information was obtained, from these results, concerning the nature of the ion-generated defects which were injected and concerning their migration behavior. It was found that the observed phenomena were due to the annihilation of di-vacancies and P-vacancy defect complexes (generated by the He implantation) by the Si self-interstitials which were injected by the shallow Si implantation.

V.Privitera, S.Coffa, F.Priolo, K.K.Larsen, G.Mannino: Applied Physics Letters, 1996, 68[24], 3422-4