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. Atomic force microscopy (AFM) characterization of CaF₂ film on Si/SiO₂ substrate: surface image of the film and its cross-section.
3. PE data:
3.1. PE spectra of CaF₂ films with varying thicknesses, as well as spectra of the bare Si/SiO₂ substrate (Fig.4).
3.2. PE spectra of the bare Si/SiO₂ substrate before and after irradiation with 1.5 keV electrons to analyze electron trapping (Fig.5).
3.3. Normalized integrated PE intensity for CaF₂ films of different thicknesses as a function of electron irradiation dose (Fig.6). The electron irradiation dose was determined by the deposition time of each CaF₂ film.
3.4. 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.7).

本数据集旨在支持对硅/二氧化硅衬底在钙氟化物(CaF₂)薄膜电子束沉积过程中的电荷捕获现象的研究。研究假设提出，电子束沉积会在二氧化硅层的缺陷中心诱导电荷捕获，这在硅/二氧化硅/钙氟化物结构的电子能谱(PE)中表现为独特的光电子(PE)峰。采用高真空条件下的紫外光子(4.2–6.2 eV)收集PE谱，以测量电子发射。结果显示，在二氧化硅衬底中存在明显的电子捕获峰，其强度随钙氟化物薄膜的厚度和电子照射剂量而变化。

数据集包含以下内容：
1. 在掠入射模式下获得的钙氟化物薄膜和二氧化硅/硅衬底的X射线衍射(XRD)图案。
2. 钙氟化物薄膜在硅/二氧化硅衬底上的原子力显微镜(AFM)表征：薄膜的表面图像及其横截面。
3. 光电子(PE)数据：
3.1. 不同厚度的钙氟化物薄膜的PE谱，以及裸露的硅/二氧化硅衬底的PE谱（图4）。
3.2. 裸露的硅/二氧化硅衬底在用1.5 keV电子照射前后的PE谱，以分析电子捕获（图5）。
3.3. 钙氟化物薄膜不同厚度的标准化积分PE强度与电子照射剂量的关系（图6）。电子照射剂量由每个钙氟化物薄膜的沉积时间确定。
3.4. 在硅/二氧化硅衬底上沉积50 nm、125 nm和277 nm厚钙氟化物薄膜后，经过不同剂量额外电子照射的PE谱（图7）。