Effect of Annealing on the Photoluminescence of Er Doped AlN Thin Films Grown by PVD Magnetron Sputtering (RF)

We report on Er3+luminescence at room temperature in the near infrared regions in amorphous and columnar AlN:Er films prepared by RF magnetron sputtering. The effect of annealing on the room temperature 1.54 μm infra-red photoluminescence intensity of erbium doped AlN films grown by r. f. magnetron sputtering, has been studied. The AlN:Er thin films were deposited on (001) Silicon substrates. The study presents relative photoluminescence intensities of nanocrystallized and columnar samples prepared with identical sputtering parameters for optimum erbium doping levels (1 atomic %). The luminescence due to rare earth ions in Al nitride thin layers can be increased by proper structural tailoring. In this contribution, we report on the photoluminescence of the rare earth ion Er3+ that is contained in films prepared by RF magnetron sputtering of Al targets with additional Er constant sector in a nitrogen atmosphere. These results are typical also for other rare earth ions, such as Eu3+, Sm3+, Tm3+ and Ce3+. Thermal annealing of the samples results in significant improvement of the photoluminescence by factors up to several tens in intensity. The intensity of the Er3+ luminescence at 1.54 μm corresponding to the 4I13/2→ 4I15/2 transition increased after annealing at 1000 °C.