摘要
The 8 μm thick single-crystalline α-Ga2O3 epilayers have been heteroepitaxially grown on sapphire(0001) substrates via mist chemical vapor deposition technique. High resolution X-ray diffraction measurements show that the full-widths-at-halfmaximum(FWHM) of rocking curves for the(0006) and(10-14) planes are 0.024° and 0.24°, and the corresponding densities of screw and edge dislocations are 2.24 × 106 and 1.63 × 109 cm-2, respectively, indicative of high single crystallinity. The out-ofplane and in-plane epitaxial relationships are [0001] α-Ga2O3//[0001] α-Al2O3 and [11-20] α-Ga2O3//[11-20] α-Al2O3, respectively.The lateral domain size is in micron scale and the indirect bandgap is determined as 5.03 eV by transmittance spectra. Raman measurement indicates that the lattice-mismatch induced compressive residual strain cannot be ruled out despite the large thickness of the α-Ga2O3 epilayer. The achieved high quality α-Ga2O3 may provide an alternative material platform for developing high performance power devices and solar-blind photodetectors.
The 8 μm thick single-crystalline α-Ga2O3 epilayers have been heteroepitaxially grown on sapphire(0001) substrates via mist chemical vapor deposition technique. High resolution X-ray diffraction measurements show that the full-widths-at-halfmaximum(FWHM) of rocking curves for the(0006) and(10-14) planes are 0.024° and 0.24°, and the corresponding densities of screw and edge dislocations are 2.24 × 106 and 1.63 × 109 cm-2, respectively, indicative of high single crystallinity. The out-ofplane and in-plane epitaxial relationships are [0001] α-Ga2O3//[0001] α-Al2O3 and [11-20] α-Ga2O3//[11-20] α-Al2O3, respectively.The lateral domain size is in micron scale and the indirect bandgap is determined as 5.03 eV by transmittance spectra. Raman measurement indicates that the lattice-mismatch induced compressive residual strain cannot be ruled out despite the large thickness of the α-Ga2O3 epilayer. The achieved high quality α-Ga2O3 may provide an alternative material platform for developing high performance power devices and solar-blind photodetectors.
基金
supported by the National Key Research and Development Project(No.2017YFB0403003)
Shenzhen Fundamental Research Project(Nos.201773239,201888588)
the National Natural Science Foundation of China(Nos.61774081,61322403)
State Key Laboratory of Wide-Bandgap Semiconductor Power Electric Devices(No.2017KF001)
the Natural Science Foundation of Jiangsu Province(No.BK20161401)
the Six Talent Peaks Project in Jiangsu Province(Mo.2014XXRJ001)
the Fundamental Research Funds for the C entral Universities(Nos.021014380093,021014380085)
