The effect of 130keV Ar ion implantation, to doses of up to 3.2 x 1016/cm2, upon defect generation in Si/oxide structures was studied by using electroluminescence techniques which involved charge injection into electrolyte/Si/SiO2 systems and which were capable of detecting defects that approached the detection limits of infra-red spectrometry. Bands at 1.9, 2.7 and 4.3eV were identified, and each band was related to various intrinsic defects in the oxide. Implantation produced an increase in the intensity of the 1.9 and 4.3eV bands (which were also present in control samples) and led to the growth of the band at 2.7eV. In general, all of the band intensities increased with increasing implantation dose. The differences between non-implanted and implanted spectra were attributed to damage which was introduced by the implantation. A structural analysis of irradiated SiO2 films, which was performed using infra-red spectroscopy, revealed that atomic displacements and broken Si-O bonds were introduced. It was suggested that the bands at 1.9, 2.7 and 4.3eV were associated with H-related defects, O vacancies and interfacial disorder, respectively. No bands were observed which were associated with impurities such as Cl or F. It was noted that the degrees of compaction and disorder of the structure were unable to explain large shifts and broadenings of the infra-red bands. It was concluded that the predominant effect of the implantation was to create point defects, such as broken bonds and atomic displacements.

S.Bota, B.Garrido, J.R.Morante, A.Baraban, P.P.Konorov: Solid-State Electronics, 1996, 39[3], 355-9