The uniformity of Al distribution in aluminum-doped zinc oxide films grown by atomic layer deposition

We investigated the aluminum distribution in aluminum-doped zinc oxide films grown by atomic layer deposition. Surface morphology, structure, composition and electrical properties of obtained films were studied. For the aluminum content less than 2 at.%, a periodicity of Al distribution along the layer depth was observed. This periodicity diminished significantly after annealing the samples in nitrogen atmosphere at 300 deg. C. For the Al content higher than 2 at.%, its distribution in ZnO:Al films was uniform within the depth measurement accuracy of ∼5-10 nm.