Impact of supplemental implantation of oxygen on defect centers in the separation by implantation of oxygen structure

Abstract

The influence of supplemental O+ implantation on standard separation-by-implantation of oxygen (SIMOX) structures in terms of inherent defects has been analyzed by electron spin resonance. The monitored defects include the Eγ′ and Eδ′ variants of the oxygen-deficiency centers in the buried oxide layer (BOX), and the likely O-related, shallow donor (UL1) centers in buried interfacial Si layers. E′ generation sensitivity depth profiles were mapped using etch back in combination with E′ generation by exposure to a dc Ar glow discharge. A major finding is that supplemental O implantation significantly reduces the E′ generation sensitivity (precursor sites) quite uniformly all over the BOX layer. The reduction, though, is about two times greater for Eδ′ as compared to Eγ′. The UL1 centers, by contrast, are seen to increase by up to a factor 6. Apparently these defects, inherent to the SIMOX formation process, are insufficiently removed by the postsupplemental O+ implantation anneal performed at 1100 °C.

Spectroscopic features of dimer and dangling bondE′ centres in amorphous silica

“…On the basis of their experimental data Griscom and Frieble [4] proposed a model in which the unpaired spin is delocalized over the tetrahedral bonds of four equivalent but different Si atoms. Another model proposed by Vanheusden and Stesmans [8] and by Warren et al [9] involved the delocalization of the unpaired electron spin over four equivalent Si atoms connected to a central tetrahedral Si atom (five-Si-atom model). A more recent model proposed by Zhang and Leisure [10] involves delocalization of the electron spin over four equivalent Si atoms around a SiO 4 vacancy (four-Si-atom model).…”

Structural inhomogeneity and silicon enrichment of buried SiO2 layers formed by oxygen ion implantation in silicon

“…The generation of the oxygen deficiency centers ͑E ␥ Ј , E ␦ Ј centers͒ caused by low energy Ar ion bombardment of bare BOX surfaces was also studied. 71,72 The damage introduced by the argon ions exhibits a strong sensitivity to the BOX processing: supplemental implantation of oxygen reduces the efficiency of the E ␥ Ј production, 72 while the reoxidation of the BOX inhibits E ␦ Ј-center generation, thus making the oxide more like thermal SiO 2 . 71 We believe that the tendency of the oxide network to create oxygen vacancy complexes during the exposure to low energy ions is related to its oxygen deficiency.…”