Blue-cathodoluminescent layers synthesis by high-dose N, C and B SiO2 implantation

Thermal silicon oxide layers have been implanted at 600 °C with N⁺+C⁺, N⁺+B⁺ and N⁺+C⁺+B⁺ ions. Two different implantation doses have been chosen in order to introduce peak concentrations at the projected range comparable to the SiO₂ density. Some pieces of the samples have been annealed in conventional furnace at 1200 °C for 3 h. After annealing, cathodoluminescence measurements show in all cases a main broad band centered at 460 nm (2.7 eV). High doses of C implantation give rise to an intensity attenuation. Phases formed in the oxides have been investigated by Fourier transform infrared spectroscopy before and after annealing. The spectra suggest that N incorporates as BN and probably as a ternary BCN phase in the triply implanted samples, while C seems to bond mainly with B. Boron is also bonded to O in B-O-Si configuration. Depth structure and quantitative composition of the films were deduced from fittings of the spectroscopic ellipsometry measurements.