Quantitative Measurements of Vacancy Defects in High-Energy Ion-Implanted Si

摘要

This paper details the quantitative measurement of excess vacancy (V~(ex)) defects created in Si via high-energy ion implantation. Qualitative evidence for the existence of these defects is predicted by Monte Carlo simulation codes like SPIM and has been confirmed experimentally. These excess defects arise due to the net displacement of the interstitials with respect to vacancies from the Frenkel pairs produced in implant damage cascades. Until recently, the quantitative measurement of vacancies (V), as compared to interstitials (I) in Si has proved to be extremely difficulty. In this work, we present recent experiments that calibrate the Au labeling technique, which can be used to profile vacancy cluster type defects in Si. The calibration, given in terms of the calibration factor, k, gives the relation between the number of vacancies and Au atoms, as obtained to be 1.2 ± 0.2. Using k, we have performed unique measurements of the dependence of excess vacancy production on implant ion dose and mass in float zone (FZ) Si(100). These preliminary experiments were compared with simulation using the Monte Carlo code SPIM. The experimental results show that the efficiency of V~(ex) production increases with increasing mass. The number of V~(ex) produced per implanted ion is ～0.0056 for B, 0.048 for Si and 0.19 for Ge. This ability to quantitatively measure vacancies in clusters via the Au labeling technique will further the understanding of damage production and its subsequent evolution under various conditions in ion-implanted Si.