Structural and surface analysis of AlInN thin films synthesized by elemental stacks annealing

This paper presents the synthesis of AlInN thin films on Si (100) substrates using elemental stacks annealing (ESA) process. Single stack InN films were grown on Si (100) substrates by reactive radiofrequency (RF) magnetron sputtering using pure indium target in Ar–N₂ environment and then an Al stack layer was deposited on the InN films by direct current (dc) sputtering of pure aluminum target in Ar atmosphere at room temperature. Annealing of the deposited films was carried out at 400 °C for 2, 4 and 6 h in a tube furnace under N₂ atmosphere. X-ray diffraction (XRD) results reveal that annealing for 2 h does not produce a well-defined AlInN film, however, with the increase of annealing time to 4 h and to 6 h, (002) and (103) oriented highly crystalline AlInN films are formed with wurtzite structures. Field emission scanning electron microscopy (FESEM) results indicate a uniform film structure with grains growth by increasing the annealing time. Energy dispersive x-ray (EDX) analysis shows higher Al (atomic %) in the film as compared to In and N. Atomic force microscopy (AFM) results show a decrease in the surface roughness with increase of the annealing time. (papers)