Monocrystalline silicon was implanted with boron (32keV, 1.3 x 1015/cm2), post-annealed (740C, 600s, N2) and further analyzed at the atomic scale by atom probe tomography. A comparison between the as-implanted and annealed samples demonstrated the presence of large B–Si clusters after annealing which were associated with the well-known boron interstitial clusters. The cluster density (up to 5 x 1017/cm3) and the number of B atoms per cluster (up to 50) were found to vary with the boron concentration. Only 8% of the B atoms were found trapped in those clusters, suggesting the presence of a majority of very small B–Si aggregates in correlation with simulations.

Atomic Scale Study of Boron Interstitial Clusters in Ion-Implanted Silicon. M.Ngamo, S.Duguay, F.Cristiano, K.Daoud-Ketata, P.Pareige: Journal of Applied Physics, 2009, 105[10], 104904