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Title: Al Incorporation up to 99% in Metalorganic Chemical Vapor Deposition‐Grown Monoclinic (Al x Ga 1–x ) 2 O 3 Films Using Trimethylgallium

Growths of monoclinic (AlxGa1−x)2O3thin films up to 99% Al contents are demonstrated via metalorganic chemical vapor deposition (MOCVD) using trimethylgallium (TMGa) as the Ga precursor. The utilization of TMGa, rather than triethylgallium, enables a significant improvement of the growth rates (>2.5 μm h−1) of β‐(AlxGa1−x)2O3thin films on (010), (100), and (01) β‐Ga2O3substrates. By systematically tuning the precursor molar flow rates, growth of coherently strained phase pure β‐(AlxGa1−x)2O3films is demonstrated by comprehensive material characterizations via high‐resolution X‐ray diffraction (XRD) and atomic‐resolution scanning transmission electron microscopy (STEM) imaging. Monoclinic (AlxGa1−x)2O3films with Al contents up to 99, 29, and 16% are achieved on (100), (010), and (01) β‐Ga2O3substrates, respectively. Beyond 29% of Al incorporation, the (010) (AlxGa1−x)2O3films exhibit β‐ to γ‐phase segregation. β‐(AlxGa1−x)2O3films grown on (01) β‐Ga2O3show local segregation of Al along (100) plane. Record‐high Al incorporations up to 99% in monoclinic (AlxGa1−x)2O3grown on (100) Ga2O3are confirmed from XRD, STEM, electron nanodiffraction, and X‐ray photoelectron spectroscopy measurements. These results indicate great promises of MOCVD development of β‐(AlxGa1−x)2O3films and heterostructures with high Al content and growth rates using TMGa for next‐generation high‐power and high‐frequency electronic devices.

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Author(s) / Creator(s):
 ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
physica status solidi (RRL) – Rapid Research Letters
Medium: X
Sponsoring Org:
National Science Foundation
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