Quantitative evolution of vacancy-type defects in high-energy ion-implanted Si: Au labeling and the vacancy implanter

In ion implantation related research in Si, the role of interstitial clusters in dopant diffusion is fairly well understood. But there is relatively poor understanding of vacancy clusters, mainly due to the inadequacy of present techniques to profile and especially to count vacancy defects. Recently, two important steps have been taken in the direction of understanding the vacancy-type defects. The first is the demonstration that high-energy ion implantation (HEI) can be used as a vacancy implanter to introduce vacancies (V) in Si that are separated from the interstitials (I) by relying on spatial separation of the Frenkel pairs due to the average forward momentum of the recoils. The second is the development of two techniques, Au labeling and cross-section X-ray microbeam diffuse scattering which permit quantitative measurements of the vacancy-type defect clusters and their depth distribution. In this work we highlight the Au labeling technique and use the vacancy implanter in conjunction with Au labeling to study the evolution of excess vacancy defects (V-ex) created by HEI of Si+ in Si(1 0 0) as a function of fluence and temperature. We show that a precise injection of V-ex is possible by controlling implanted fluence. We also show that the V-ex clusters formed by the HEI are extremely stable and their annihilation is governed by interstitial injection rather than vacancy emission in the temperature range of 800-900 degreesC. (C) 2001 Elsevier Science B.V. All rights reserved.