EFG 법으로 성장시킨 β-Ga₂O₃ 단결정의 다양한 결정면, off-angle에 따른 epitaxial layer의 특성 분석
Characterization of epitaxial layers on beta-gallium oxide single crystals grown by EFG method as a function of different crystal faces and off-angle
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초록
β-Ga₂O₃는 4.9 eV의 넓은 밴드갭과 8 MV/cm의 높은 항복전압으로 전력 소자 응용 분야에서 많은 관심을 받고 있는 대표적인 UWBG(Ultra-wide Band-gap) 반도체이다. 또한 용액 성장이 가능하기 때문에 SiC, GaN에 비해 성장 속도가 빠르고 생산 비용이 저렴하다는 장점이 있다 [1,2]. 본 연구에서는 EFG(Edge-defined Film-fed Growth) 법을 통해 Si 도핑된 β-Ga₂O₃ 단결정을 성장시키는 데에 성공하였다. 성장 방향과 성장 주 면은 각각 [010] / (001)로 설정하였으며 성장속도는 7~20 mm/h이다. 성장시킨 β-Ga₂O₃ 단결정은 다양한 결정 면 방향 (001, 100, 201)과 off-angle(1°, 3°, 4°)에 따라 절단하여 표면 가공을 진행하였고, 가공 후 HVPE(Halide vapor phase epitaxy) 법을 이용해 epi-ready 기판 위에 homoepitaxial층을 성장시켰다. 가공 후의 샘플과 epi-layer를 성장시킨 샘플을 XRD, AFM, OM, Etching 등의 분석을 통해 결정면과 off-angle에 따른 표면 특성을 비교하였다.
Abstract
β-Ga₂O₃ is a representative ultra-wide bandgap (UWBG) semiconductor that has attracted much attention for power device applications due to its wide-bandgap of 4.9 eV and high-breakdown voltage of 8 MV/cm. In addition, because solution growth is possible, it has advantages such as fast growth rate and lower roduction cost compared to SiC and GaN [1-2]. In this study, we have successfully grown Si-doped 10 mm thick Si-doped β-Ga₂O₃ single crystals by the EFG (Edge-defined Film-fed Growth) method. The growth direction and growth principal plane were set to [010] / (010), respectively, and the growth speed was 7~20 mm/h. The as-grown β-Ga₂O₃ single crystal was cut into various crystal planes (001, 100, 201) and off-angles (1°, 3°, 4°), and then surface processed. After processed, the homoepitaxial layer was grown on the epi-ready substrate using the HVPE(Halide vapor phase epitaxy) method. The processed samples and the epi-layer grown samples were analyzed by XRD, AFM, OM, and Etching to compare the surface properties according to the crystal plane and off-angle.
참고문헌 (22)
- M. Higashiwaki, "Guest editorial : The dawn of gallium oxide microelectronics", Appl. Phys. Lett, 112, pp.060401~ (2018)
- S. Zhang, "Growth and characterization of 2-inch high quality β-Ga2O3 single crystals grown by EFG method", J. Semicond, 39, pp.083003~ (2018)
- J. B. Varley, "Hydrogenated cation vacancies in semiconducting oxides : Origin of doping asymmetry", J. Phys. : Condens. Matter, 23, pp.334212~ (2011)
- K. Sasaki, "Device-quality β-Ga2O3 epitaxial films fabricated by ozone molecular beam epitaxy", Appl. Phys. Express, 5, pp.035502~ (2012)
- A. Kuramata, "High-quality β-Ga2O3 single crystals grown by edge-defined film-fed growth", Jpn. J. Appl. Phys, 55, pp.1202A2~ (2016)
- H. W. Xue, "An overview of the ultrawide bandgap Ga2O3 semiconductorbased Schottky barrier diode for power electronics application", Nanoscale Research Letters, 13, pp.1~ (2018)
- M. Higashiwaki, "Gallium Oxide:Materials Properties, Crystal Growth, and Devices" (2020), Springer International Publishing
- P. Vogt, "Reaction kinetics and growth window for plasma-assisted molecular beam epitaxy of Ga2O3 : Incorporation of Ga vs. Ga2O desorption", Appl. Phys. Lett, 108, pp.072101~ (2016)
- P. Vogt, "Kinetics versus thermodynamics of the metal incorporation in molecular beam epitaxy of(InxGa1-x)2O3", APL Mater, 4, pp.086112~ (2016)
- K. Sasaki, "Growth temperature dependences of structural and electrical properties of Ga2O3 epitaxial films grown on -Ga2O3(010)substrates by molecular beam epitaxy", J. Cryst. Growth, 392, pp.30~ (2014)
- G. Wagner, "Homoepitaxial growth of β-Ga2O3 layers by metal-organic vapor phase epitaxy", Physica Status Solidi(a), 211, pp.27~ (2014)
- X. Du, "Characterization of homoepitaxial β-Ga2O3 films prepared by metal-organic chemical vapor deposition", J. Cryst. Growth, 404, pp.75~ (2014)
- M. Orita, "Deepultraviolet transparent conductive β-Ga2O3 thin films", Appl. Phys. Lett, 77, pp.4166~ (2000)
- T. Oshima, "Epitaxial growth of β-Ga2O3 films by mist chemical vapor deposition", J. Cryst. Growth, 359, pp.60~ (2012)
- H. Murakami, "Homoepitaxial growth of β-Ga2O3 layers by halide vapor phase epitaxy", Appl. Phys. Express, 8, pp.015503~ (2014)
- Y. Oshima, "Halide vapor phase epitaxy of twin-free β-Ga2O3 on sapphire(0001)substrates", Appl. Phys. Express, 8, pp.055501~ (2015)
- Y. Oshima, "Quasi-heteroepitaxial growth of β-Ga2O3 on off-angled sapphire(0001)substrates by halide vapor phase epitaxy", J. Cryst. Growth, 410, pp.53~ (2015)
- K. Goto, "Effect of substrate orientation on homoepitaxial growth of β-Ga2O3 by halide vapor phase epitaxy", Appl. Phys. Lett, 120, pp.102102~ (2022)
- K. Ogawa, "AFM observation of etch-pit shapes on β-Ga2O3 (001) surface formed by molten alkali etching, MSF 1004", 512~ (2020)
- S. Sdoeung, "Characterization of dislocation of halide vapor phase epitaxial (001) β-Ga2O3 by ultrahigh sensitive emission microscopy and synchrotron X-ray topography and its influence on Schottky barrier diodes", Jpn. J. Appl. Phys, 62(SF), pp.SF1001~ (2023)
- A. A. Zarichny, "The analysis of the etch pits parameters in the(201)plane of the β-Ga2O3 substrate crystals", Materials Physics and Mechanics, 51, pp.174~ (2023)
- Y. Liu, "Two types of etching pits in(100)β-Ga2O3 single crystals grown by casting method", Micro and Nanostructures, 176, pp.207541~ (2023)