A channeling/RBS study of SOI structures by SIMOX using MeV ions

Abstract

Silicon-on-insulator (SOI) structures, formed by implanting n-type 〈100〉 silicon substrates with 3 × 10 17, 6 × 10 17 and 8 × 10 17 O 2+ ions cm −2 at 6 MeV, have been characterized by channeling/Rutherford backscattering spectroscopy (RBS). An amorphous buried layer was formed about 4 μm from the surface. In the as-implanted samples, the Si overlayer was damaged from the surface to the buried layer, but still monocrystalline. After annealing at 1300°C for 2 h, the crystal structure is restored from the surface to a depth around 3.2 μm. RBS spectra showed that samples annealed at 1300°C for 6 h exhibited narrower oxygen distributions than those annealed at 1240°C for longer time (13 h). For the largest dose (8 × 10 17 ions cm −2), a nearly stoichiometric oxide layer was formed after annealing at 1300°C for 6 h.