Ex-situ AlN seed layer for (0001)-textured Al0.84Sc0.16N thin films grown on SiO2 substrates
| Autor: | Stefan Mertin, Pascal Nicolay, Cosmin S. Sandu, Vladimir Pashchenko, Nicolas Kurz, Paul Muralt, Fazel Parsapour |
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| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Materials science Oxide Analytical chemistry Nanotechnology 02 engineering and technology 021001 nanoscience & nanotechnology Epitaxy 01 natural sciences chemistry.chemical_compound Electron diffraction chemistry Etching (microfabrication) 0103 physical sciences Texture (crystalline) Thin film 0210 nano-technology Layer (electronics) Deposition (law) |
| Zdroj: | 2017 IEEE International Ultrasonics Symposium (IUS). |
| DOI: | 10.1109/ultsym.2017.8091524 |
| Popis: | It is more difficult to nucleate AlN-ScN alloy thin films (AlScN) in pure (0001)-texture than it is with pure AlN thin films. AlN thus can serve as seed layer for AlScN. Equipment limitations may lead to the problem of a vacuum break between AlN and AlScN deposition, as it leads to oxidation of the AlN surface. This issue was studied with high resolution TEM and electron diffraction. The formed oxide layer disturbed a lot the epitaxial growth, leading to additional grain orientations. A mild RF etching step introduced before AlScN deposition was able to remove the oxide layer, and allowed for growing Al 0.84 Sc 0.16 N in local epitaxy on AlN, as shown by Hyper map EDX images. The resulting AlScN films show a pure (0001) texture. Double beam laser interferometry and finite element modeling were used to determine d 33, f of both layers together as 6.6 pm/V, and of 6.85 pm/V for AlScN alone when using the standard value of 3.9 pm/V for pure AlN. At the same time, the relative dielectric constant of Al 0.84 Sc 0.16 N was determined as 14.1. |
| Databáze: | OpenAIRE |
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