INFLUENCE OF ANNEALING TREATMENT ON THE PHYSICAL PROPERTIES OF InAlN FILMS

Abstract

In this work, pure indium and aluminum targets were co-sputtered in a reactive argon-nitrogen environment at 200 C to deposit InAlN¯lm on the GaAs substrate in the presence of a ZnO bu®er layer. The as-grown¯lm was annealed at 750 C for 1 h in a high temperature furnace under nitrogen ambient. XRD pattern of the as-grown¯lm did not display any di®raction peak relating to the InAlN due to its poor structural crystallinity, however, the annealed¯lm exhibited InAlN di®raction peaks corresponding to (002), (101) and (102) planes. A signi¯cant increase in the grain size and the surface roughness was observed after the¯lms' annealing. Raman spectroscopy revealed A 1 (LO) and E 2 (high) phonon modes whereas the PL analysis showed a luminescence peak at 2 eV in the annealed¯lm. The Hall measurements indicated an increase in the carrier concentration and electron mobility after the annealing which was accompanied by a decrease in electrical resistivity of thē lm. The dark current-voltage (I-V ) characteristics of the as-grown and the annealed¯lms were also recorded to investigate the barrier height and the ideality factor.