Electrical and structural characterization of YAlN at high alloy concentrations

Abstract

YxAl1−xN in its wurtzite phase has been identified as a prospective wide bandgap semiconductor and a promising competitor of ScxAl1−xN in application devices. Notwithstanding theoretical predictions of the high stability of YxAl1−xN in the wurtzite structure even at high alloy concentrations, experimental studies have revealed significant challenges in achieving the requisite high concentration films. This study demonstrates that strain is an effective parameter on the growth of wurtzite YxAl1−xN, which can be tuned by engineering growth methods, such as the introduction of different buffer layers. Conversely, difficulties have been encountered in achieving Y concentrations above x = 0.4, despite the incorporation of Y atoms into the layers, with the formation of amorphous structures occurring prior to the predicted structural phase transition to the rock salt crystal. A comprehensive grasp of the structural characteristics of YxAl1−xN thin films offers invaluable insight that will prove to be beneficial for future research on this material system.