Demonstration of single-phase wurtzite BAlN with over 20% boron content by metalorganic chemical vapor deposition
Type
ArticleKAUST Department
Advanced Semiconductor LaboratoryComputer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division
Electrical Engineering Program
Material Science and Engineering Program
Physical Science and Engineering (PSE) Division
Date
2020-08-27Online Publication Date
2020-08-27Print Publication Date
2020-08-24Submitted Date
2020-06-26Permanent link to this record
http://hdl.handle.net/10754/664931
Metadata
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Wurtzite BAlN alloys are emerging ultrawide bandgap III-nitride semiconductors promising for optical and electronic devices. Yet the boron compositions of the grown alloys have been limited. In this Letter, we report on the demonstration of a thick single-phase wurtzite BAlN film with a boron composition over 20%. The growth was conducted at 1010 C and 150 Torr with continuous flows of group-III precursors and ammonia with a growth rate of 2.2 lm/h by metalorganic chemical vapor deposition. The boron composition was studied by x-ray diffraction (XRD), secondary neutral mass spectrometry (SNMS), and Rutherford backscattering spectrometry (RBS). The XRD 2h scan exhibited the clear wurtzite BAlN peak 1.82 larger than the AlN peak, indicating the boron composition of 30.9% based on the lattice constants of wurtzite AlN and BN. The SNMS and RBS experiments, independent of strain and defects, revealed that the boron content was 22%. The microstructures of the wurtzite BAlN film were further studied by transmission electron microscopy, showing an initial 5 nm thick layer free of crystal twinning followed by widespread crystal twinning with lattice rotations of 60 clockwise and anti-clockwise. The optical transmission experiment manifested that the bandgap of the smaller-lattice BAlN film was 5.1 eV, smaller than that of larger-lattice AlN. This trend was the opposite of the conventional InGaAlN but consistent with theoretical predictions. This study would greatly facilitate the research of material, physics, and devices incorporating the wurtzite BAlN alloys.Citation
Tran, T. B., Liao, C.-H., AlQatari, F., & Li, X. (2020). Demonstration of single-phase wurtzite BAlN with over 20% boron content by metalorganic chemical vapor deposition. Applied Physics Letters, 117(8), 082102. doi:10.1063/5.0019881Publisher
AIP PublishingJournal
Applied Physics LettersAdditional Links
http://aip.scitation.org/doi/10.1063/5.0019881ae974a485f413a2113503eed53cd6c53
10.1063/5.0019881