Photo-injection study of SIMOX structures with supplemental oxygen implant

Previous photo-injection studies of SIMOX structures have shown that there are electron traps and amphoteric photo-sensitive defects in the buried oxide (BOX) layer; the latter ones appeared to be amorphous Si clusters rather than network point defects. It was also observed that heat treatment in argon at 1100°C of “pseudoSIMOX” sample (top Si layer removed) almost completely eliminated the Si clusters; this effect was attributed to modifying the properties of the Si-cluster/oxide interface, but another possibility is that oxygen contamination in the argon oxidized the clusters. It was further shown by photo-current measurements that supplemental implantation of 10¹⁷ O/cm² into single-implanted samples resulted in about 1/10 reduction in the density of trapped electrons (injected at the 10¹⁵ e/cm² level). The purpose of this work was to study the effects of supplemental oxygen implantation in greater detail by using single and triple implanted SIMOX structures with nominally 400 nm thick BOX layers. A so-called equilibrium-oxide sample, prepared with such a high dose of oxygen that no superficial Si layer is present at all and annealed as regular SIMOX samples, was also studied