Piezoelectric and structural properties of c-axis textured aluminium scandium nitride thin films up to high scandium content
| Autor: | Marc Dubois, Gabriel Christmann, Oliver Rattunde, Stefan Mertin, Paul Muralt, Sylvain Nicolay, Bernd Heinz |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Scanning electron microscope C-axis texture chemistry.chemical_element Piezoelectric thin films 02 engineering and technology 01 natural sciences Reactive magnetron sputtering chemistry.chemical_compound Aluminium Sputtering 0103 physical sciences Materials Chemistry Electron microscopy Scandium Composite material Thin film Aluminium scandium nitride Wurtzite crystal structure 010302 applied physics Aluminium nitride Surfaces and Interfaces General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Piezoelectricity Surfaces Coatings and Films X-ray diffraction chemistry 0210 nano-technology |
| Zdroj: | Mertin, S, Heinz, B, Rattunde, O, Christmann, G, Dubois, M A, Nicolay, S & Muralt, P 2018, ' Piezoelectric and structural properties of c-axis textured aluminium scandium nitride thin films up to high scandium content ', Surface and Coatings Technology, vol. 343, pp. 2-6 . https://doi.org/10.1016/j.surfcoat.2018.01.046 |
| ISSN: | 1879-3347 0257-8972 |
| DOI: | 10.1016/j.surfcoat.2018.01.046 |
| Popis: | Partial substitution of aluminium by scandium in the wurtzite structure of aluminium nitride (AlN) leads to a large increase of the piezoelectric response by more than a factor of 2. Therefore, aluminium scandium nitride (ASN) thin films attracted much attention to improve piezoelectric MEMS devices such as RF filters, sensors, micro actuators and energy harvesting devices. In this work, process-microstructure-property relationships of ASN thin films containing up to 42% Sc were investigated. Like AlN thin films, ASN films are sputter deposited at 300–350°C with pulsed DC powered magnetrons. The influence of the process parameters on the film structure, the intrinsic stress and the piezoelectric response was investigated in order to achieve optimal piezoelectric coefficients up to high Sc concentrations. X-Ray diffraction (XRD) and transmission electron microscopy (TEM) were used to analyse the quality of c-axis texture. The films showed exclusively (002) texture with rocking-curve widths in the range of 1.3–2° (FHWM). The films were further analysed by scanning electron microscopy (SEM). The Sc content was determined by energy-dispersive X-ray spectroscopy (EDX). A good compositional homogeneity in the range of 0.5–1 at.% was achieved between border and centre of 200-mm wafers. So far, we obtained ASN films with transversal piezoelectric coefficients of up to e31,f = −2.77 C/m2, which is a factor 2.6 higher than in pure AlN thin films. |
| Databáze: | OpenAIRE |
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