Luminescence of insulator layers on silicon excited by electrons
Keywords:cathodoluminescence, electroluminescence, molecular layer deposition, spectral distribution, electronic structure, luminescence centers
We present a comparative analysis of cathodoluminescence (CL) and electroluminescence (EL) spectra measured on Si–SiO2 and Si–Ta2O5 structures with various thicknesses of insulator layers. Spectral distribution of luminescence depends on how the insulator layer was formed, its thickness and type of excitation. The analysis indicates that CL and EL spectra of Si–SiO2 structures, grown by thermal oxidation of silicon in “dry” oxygen, are almost identical in spectral composition. Based on the dependence of intensity of the luminescence band with a maximum at energy of 2.2 eV, it was concluded that the corresponding luminescence centers are uniformly distributed over the oxide layer thickness in the range of 30–200 nm. It is assumed that these luminescence centers are oxygen vacancies formed during the thermal oxidation of silicon. In the case of Ta2O5 layers on silicon, the presence of defects (luminescence centers) in the oxide layer leads to the formation of a set of energy levels in the band gap of the Ta2O5 layers obtained by ALD. They appear in the luminescence spectra regardless of the excitation method.
Babaran, A. P., Bulavinov, V. V., Troshikhin, A. G. (1993) Changes in the state of Si-SiO2 structures studied by the method of field cycling in a system with electrolytic contacts. Technical Physics Letters, 19 (9), 577–578. (In English)
Baraban, A.P., Denisov, E. A., Dmitriev, V. A. et al. (2020) Features of SiO2 layers synthesized on silicon by molecular layer deposition. Semiconductors, 54 (4), 506–510. https://www.doi.org/10.1134/S106378262004003X (In English) Baraban, A. P., Dmitriev, V. A., Petrov, Yu. V. (2009) Elektrolyuminestsentsiya tverdotel’nykh sloistykh struktur na osnove kremniya [Electroluminescence in silicon-based solid-state layered structures]. Saint Petersburg: Saint Petersburg State University Press, 195 p. (In Russian) Baraban, A. P., Dmitriev, V. A., Petrov, Yu. V., Timofeeva, K. A. (2012) Electron-excited luminescence of SiO2 layers on silicon. Physics of the Solid State, 54 (6), 1149–1152. https://www.doi.org/10.1134/S1063783412060066 (In English)
Baraban, A. P., Dmitriev, V. A., Prokof’ev, V. A. et al. (2016) Photoluminescence of Ta2O5 films formed by the molecular layer deposition method. Technical Physics Letters, 42 (4), 341–343. https://www.doi.org/10.1134/ S1063785016040040 (In English)
Baraban, A. P., Selivanov, A. A., Dmitriev, V. A. et al. (2019) Cathodoluminescence of TiO2 films formed by molecular layer deposition. Technical Physics Letters, 45 (3), 256–258. https://www.doi.org/10.1134/S1063785019030210 (In English)
Baraban, A. P., Samarin, S. N., Prokofiev, V. A. et al. (2019) Luminescence of SiO2 layers on silicon at various types of excitation. Journal of Luminescence, 205, 102–108. https://www.doi.org/10.1016/j.jlumin.2018.09.009 (In English)
Coenen, T., Haegel, N. M. (2017) Cathodoluminescence for the 21st century: Learning more from light. Applied Physics Reviews, 4 (3), article 031103. https://www.doi.org/10.1063/1.4985767 (In English)
Drouin, D. (2006) CASINO a powerful simulation tool for cathodoluminescence applications, Microscopy and Microanalysis, 12 (S02), 1512–1513. https://www.doi.org/10.1017/S1431927606069686 (In English)
Yacobi, B. G., Holt, D. B. (1990) Cathodoluminescence. In: Cathodoluminescencemicroscopy of inorganic solids. Boston: Springer Publ., pp. 55–88. https://www.doi.org/10.1007/978-1-4757-9595-0_4 (In English)
Zamoryanskaya, M. V., Sokolov, V. I. (1998) Structural study of thermal-oxide films on silicon by cathodoluminescence. Physics of the Solid State, 40 (11), 1797–1801. https://www.doi.org/10.1134/1.1130659 (In English)
Copyright (c) 2021 Alexander P. Baraban, Valentin A. Dmitriev
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
The work is provided under the terms of the Public Offer and of Creative Commons public license Attribution-NonCommercial 4.0 International (CC BY-NC 4.0). This license allows an unlimited number of persons to reproduce and share the Licensed Material in all media and formats. Any use of the Licensed Material shall contain an identification of its Creator(s) and must be for non-commercial purposes only.