The diffusion of In in both the top Si and the buried oxide (BOX) layers in separation by implantation of O (SIMOX) was investigated. For all In-implanted samples, there was a significant redistribution of In atoms from the top Si/BOX interface towards the bottom BOX/Si interface, thereby affecting the In concentrations in the two Si/BOX interfaces. In the case of relatively high-dose and high-energy In implantation (1014/cm2 at 200keV), an anomalous segregation of In was observed in both the bulk Si and the SIMOX substrates. However, there was a notable transportation of In atoms from the top Si layer towards the bottom BOX/Si interface in the SIMOX; thus affecting not only the In concentrations in the two Si/BOX interfaces but also the In distribution in the top Si layer. The unique In-diffusion behavior in the SIMOX was believed to be a composite effect of In-trapping by the two Si/BOX interfaces, with In atoms being drawn away from the top Si layer by the buried oxide, as well as implant damage in the top Si. The asymmetrical structure of the BOX layer, with Si islands accumulating at the bottom BOX/Si interface, and the abundance of O-related defects in the BOX layer were also believed to be responsible for the In-diffusion behavior in the BOX layer.

Effects of Buried Oxide Layer on Indium Diffusion in Separation by Implantation of Oxygen. P.Chen, M.Zhu, R.K.Y.Fu, P.K.Chu, Z.An, W.Liu, N.Montgomery, S.Biswas: Journal of Applied Physics, 2004, 96[6], 3217-20