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.