A new experimental method of studying shifts between concentration-versus-depth profiles of vacancy-type and interstitial-type defects in ion-implanted Si was demonstrated. The concept was based on deep level transient spectroscopy measurements utilizing the filling pulse variation technique. The vacancy profile, represented by the vacancy-O center and the interstitial profile, represented by the substitutional C-interstitial C pair, were obtained at the same sample temperature by varying the duration of the filling pulse. Thus the two profiles could be recorded with a high relative depth resolution. Point defects were introduced in low doped float zone n-type Si by implantation with 6MeV B ions and 1.3MeV protons at room temperature, using low doses. For each implantation condition the peak of the interstitial profile was shown to be displaced by about 0.5μm towards larger depths compared to that of the vacancy profile. This shift was primarily attributed to the preferential forward momentum of recoiling Si atoms, in accordance with theoretical predictions.

Separation of Vacancy and Interstitial Depth Profiles in Proton- and Boron-Implanted Silicon. P.Pellegrino, P.Lévêque, H.Kortegaard-Nielsen, A.Hallén, J.Wong-Leung, C.Jagadish, B.G.Svensson: Nuclear Instruments and Methods in Physics Research B, 2002, 186[1-4], 334-8