High-quality β-(Al x Ga 1- x ) 2 O 3 heteroepitaxy grown on (010) Ga 2 O 3 via MOCVD and transistor demonstration

Abstract This work demonstrates the heteroepitaxial growth of single-phase β -(Al x Ga 1− x ) 2 O 3 on (010) β -Ga₂O₃ substrates via metalorganic chemical vapor deposition, achieving an aluminum composition of up to 22.6% with no phase segregation characterized by x-ray diffractometer. The surface morphology of epitaxial layer becomes rougher initially and then smoother with the increase of Al composition, suggesting that the rising Al composition leads to changes in the epitaxial growth mode. The fabricated MOSFETs based on β -(Al 0.09 Ga 0.91 ) 2 O 3 epitaxial film achieve an ultra-high breakdown voltage over 3000 V and a high average breakdown field of 2.3 MV cm −1 . This work underscores the potential of β -(Al x Ga 1− x ) 2 O 3 heteroepitaxy technique and showcases its suitability for high-voltage power device applications.