Spatial resolution and cathodoluminescence intensity dependence on acceleration voltage in electron beam excitation assisted optical microscopy using Y2O3:Eu3+ film.

This study presents relationship between acceleration voltage and spatial resolution of electron-beam assisted (EXA) optical microscope. The nanometric illumination light sources of the present EXA microscope was red-emitting cathodoluminescence (CL) in the Y2O3:Eu3+ thin film excited by focused electron beam. Our experimental results demonstrated that the spatial resolutions of the EXA microscope were higher as the acceleration voltage was higher. We managed to make images of the scattered gold particles with approximately 90 nm-resolutions at the voltages higher than 20 kV. The dependence of the spatial resolution on the acceleration voltage was explained by the distribution of simulated electron scattering trajectories in the luminescent thin film.

Fabrication of bright and thin Zn2SiO4 luminescent film for electron beam excitation-assisted optical microscope.

We fabricated a bright and thin Zn2SiO4 luminescent film to serve as a nanometric light source for high-spatial-resolution optical microscopy based on electron beam excitation. The Zn2SiO4 luminescent thin film was fabricated by annealing a ZnO film on a Si3N4 substrate at 1000 °C in N2. The annealed film emitted bright cathodoluminescence compared with the as-deposited film. The film is promising for nano-imaging with electron beam excitation-assisted optical microscopy. We evaluated the spatial resolution of a microscope developed using this Zn2SiO4 luminescent thin film. This is the first report of the investigation and application of ZnO/Si3N4 annealed at a high temperature (1000 °C). The fabricated Zn2SiO4 film is expected to enable high-frame-rate dynamic observation with ultra-high resolution using our electron beam excitation-assisted optical microscopy.