Investigation of deep implanted carbon and oxygen channeling profiles in [110] silicon, using d-NRA and SEM

Abstract

Ion implantation is one of the most important techniques used in the silicon-based semiconductor industry. Using the ion axial channeling effect, which occurs when an ion beam is oriented along a crystallographic axis, it is theoretically possible to implant ions deeper in the crystal, in comparison with the random ion beam-solid orientation, while - at the same time - minimizing the induced crystal lattice damage. In the present work, 4 MeV C-12(2+) and 5 MeV O-16(2+) ions were implanted in high-purity [1 1 0] Si crystal wafers at fluences of the order of similar to 10(17) particles/cm(2), in both the channeling and random orientations. The resulting profiles were measured using d-NRA, i.e. implementing the C-12(d,p(0)) and O-16(d,p(0),alpha(0)) reactions respectively, at E-d,E-lab = 1.2-1.4 MeV. The results were validated using SEM (Scanning Electron Microscopy), while the extent of crystalline damage was monitored during the implantation via RBS/C (Rutherford Backscattering Spectrometry/Channeling) spectra. The resulting profiles seem to be in good agreement with those obtained in the past for fluorine and nitrogen ions implanted in silicon, and clearly demonstrate the capabilities of high-energy channeling implantations, as well as, the accuracy of d-NRA (Nuclear Reaction Analysis) profiling measurements.