Effect of reactive gas composition on properties of Si/LiNbO3 heterojunctions grown by radio-frequency magnetron sputtering
| Autor: | A. Grebennikov, D. Serikov, V. M. Ievlev, M. Sumets, D. Goloshchapov, P. Seredin, V. Dybov, E. K. Belonogov |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Silicon Band gap Materials Science (miscellaneous) Analytical chemistry chemistry.chemical_element 02 engineering and technology Dielectric LiNbO3 010402 general chemistry 01 natural sciences law.invention Annealing Biomaterials law lcsh:TA401-492 Crystallization Heterojunction Sputter deposition Lithium niobate 021001 nanoscience & nanotechnology 0104 chemical sciences Electronic Optical and Magnetic Materials Amorphous solid chemistry Ceramics and Composites lcsh:Materials of engineering and construction. Mechanics of materials Crystallite 0210 nano-technology Magnetron sputtering |
| Zdroj: | Journal of Science: Advanced Materials and Devices, Vol 5, Iss 4, Pp 512-519 (2020) |
| ISSN: | 2468-2179 |
| Popis: | Amorphous lithium niobate (LiNbO3) films were deposited onto silicon substrates by the radio-frequency magnetron sputtering method in a pure Ar environment and an Ar + O2 gas mixture with various oxygen contents. The oxide charge existing in as-grown films has two components: the positive +Qox distributed in the bulk of a film and the negative −Qox located at the film/substrate interface with a maximum magnitude corresponding to an Ar (80%) + O2 (20%) gas mixture. The potential barrier height, φ, at the LiNbO3/Si interface correlates with Qox. The lowest φ value is attributed to the LiNbO3/Si heterostructures fabricated under an Ar/O2 = 60/40 gas ratio. The electron traps, affecting the charge transport are distributed exponentially in the bandgap of as-grown amorphous LN films with the “smoothest” distribution, corresponding to the films deposited in an Ar (60%) + O2 (40%) gas mixture. Thermal annealing (TA) leads to the crystallization of as-grown films, decreasing the −Qox value greatly in heterostructures fabricated in an Ar + O2 environment, and declining the φ value. The φ value is insensitive to the crystallization of LN films deposited in a pure Ar environment. The recrystallization process occurring under TA turns the trap distribution into uniform one. The dielectric constant of polycrystalline LiNbO3 films, fabricated in both (Ar (80%) + O2 (20%) and Ar (60%) + O2 (40%)) gas mixtures and annealed at 550 °C, is higher than that of the films deposited in a pure Ar atmosphere. |
| Databáze: | OpenAIRE |
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