AlN thin film structures have many useful and practical piezoelectric and pyroelectric properties. The potential enhancement of the AlN piezo- and pyroelectric constants allows it to compete with more commonly used materials. For example, combination of AlN with ScN leads to new structural, electronic, and mechanical characteristics, which have been reported to substantially enhance the piezoelectric coefficients in solid-solution AlN-ScN compounds, compared to a pure AlN-phase material.
In our work, we demonstrate that an analogous alloying approach results in considerable enhancement of the pyroelectric properties of AlN - ScN composites. Thin films of ScN, AlN and Al
ScxN (x = 0 – 1.0) were deposited on silicon (004) substrates using dual reactive sputtering in Ar/N2 atmosphere from Sc and Al targets. The deposited films were studied and compared using x-ray diffraction, XPS, SEM, and pyroelectric characterization. An up to 25% enhancement was observed in the pyroelectric coefficient (Pc = 0.9 µC /m2K) for Sc
N thin films structures in comparison to pure AlN thin films (Pc = 0.71 µC/m2K). The obtained results suggest that Al
ScxN films could be a promising novel pyroelectric material and might be suitable for use in uncooled IR detectors.