Structural and surface characterization of magnetron sputtered In1−xAlxN films grown on GaAs substrates

• In1−xAlxN films were grown on ZnO/GaAs substrates using magnetron sputtering.
• Al power was varied between 100 W and 300 W to obtain different film compositions.
• Intensity of the films decreased with increase of the Al contents in film.
• The compact film structure was changed to relatively loose one at higher Al power.

This paper reports the structural and surface features of In1−xAlxN films grown on GaAs substrates with ZnO buffer layer by using reactive magnetron co-sputtering of Al and In targets in Ar–N2 at 100 °C. The Al sputtering power was varied between 100 W and 300 W with respect to the fixed In power (50 W) to obtain different compositions of the films. X-ray diffraction (XRD) studies revealed the formation of nanostructured In1−xAlxN films along (0002) and (101¯1) planes with composition ‘x’ ranging from 0.4 to 0.9. Intensity of the diffraction peaks and crystallite size were decreased with increase of the Al contents in the film. Field emission scanning electron microscopy (FESEM) results indicated that a compact film structure changes into a relatively loose structure by increasing the Al power.