Probing structural and chemical evolution in (AlxGa1−x)2O3 using atom probe tomography: A review

(Al_xGa_1−x)₂O₃ is a novel ultra‐wide bandgap semiconductor with the potential to dominate future power electronics industries. High‐performance devices demand high Al content in (Al_xGa_1−x)₂O₃ but are limited by crystallinity degradation resulting from phase separation. Additionally, the solubility limit of Al is still under debate, and conclusive research is in progress. (Al_xGa_1−x)₂O₃ is also limited in high‐frequency applications owing to low carrier mobility and requires n‐type doping. For commercializing this material, the major obstacle is understanding dopant's behavior in the host (Al_xGa_1−x)₂O₃. To investigate these issues, an advanced characterization technique, atom probe tomography (APT), was employed to analyze the structural‐chemical evolution of (Al_xGa_1−x)₂O₃. In this review, we summarized our recent works on the structure‐chemistry investigation of (Al_xGa_1−x)₂O₃ with alloy composition and doping interaction. We introduced machine learning algorithms on APT data to reveal unrivaled knowledge, previously not achievable with conventional methodologies. The outstanding capabilities of APT to study (Al_xGa_1−x)₂O₃ with Al composition and doping will be considered significant for the wide bandgap semiconductors community. [Figure not available: see fulltext.]