Charge Trapping in SiO₂ Substrate during Electron Beam Deposition of CaF₂ Thin Films

This dataset supports the study of charge trapping phenomena in Si/SiO₂ substrates during the electron beam deposition of CaF₂ thin films of varying thicknesses (50-277 nm). The research hypothesis suggests that electron beam deposition induces charge trapping in the defect centers of the SiO₂ layer which is observed as distinct photoelectron (PE) peaks in the PE spectra of Si/SiO₂/CaF₂ structures. PE spectra were collected under high vacuum conditions using ultraviolet photons (4.2–6.2 eV) to measure electron emission. The results reveal distinct electron trapping peaks in the SiO₂ substrate, with their intensity varying depending on the thickness of the CaF₂ films and the electron irradiation dose.

The dataset includes:
1. X-Ray diffraction (XRD) patterns of CaF₂ films and SiO₂/Si substrate obtained in the grazing incidence mode.
2. X-Ray photoelectron spectroscopy (XPS) of CaF₂ film on on Si/SiO₂ substrate.
3. Atomic force microscopy (AFM) characterization of CaF₂ film on Si/SiO₂ substrate: surface image of the film and its cross-section.
4. PE data:
4.1. PE spectra of CaF₂ films with varying thicknesses, as well as spectra of the bare Si/SiO₂ substrate (Fig.5).
4.2. PE spectra of the bare Si/SiO₂ substrate before and after irradiation with 1.5 keV electrons to analyze electron trapping (Fig.6).
4.3. Normalized integrated PE intensity for CaF₂ films of different thicknesses as a function of electron irradiation dose (Fig.7). The electron irradiation dose was determined by the deposition time of each CaF₂ film.
4.4. PE spectra of 50 nm, 125 nm, and 277 nm thick CaF₂ films on Si/SiO₂ substrates after additional electron irradiation with varying doses (Fig.8).