Heteroepitaxial growth of Ga2O3 on 4H-SiC by liquid-injection MOCVD for improved thermal management of Ga2O3 power devices

Fedor Hrubišák, Kristína Hušeková, Xiang Zheng*, Alica Rosová, Edmund Dobročka, Milan Ťapajna, Matej Mičušík, Peter Nádaždy, Fridrich Egyenes, Javad Keshtkar, Eva Kováčová, James W Pomeroy, Martin Kuball, Filip Gucmann*

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

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We report on the growth of monoclinic β- and orthorhombic κ-phase Ga2O3 thin films using liquid-injection metal-organic chemical vapor deposition on highly thermally conductive 4H-SiC substrates using gallium (III) acetylacetonate or tris(2,2,6,6-tetramethyl-3,5-heptanedionato) gallium (III). Both gallium precursors produced the β phase, while only the use of the latter led to growth of κ-Ga2O3. Regardless of the used precursor, best results for β-Ga2O3 were achieved at a growth temperature of 700 °C and O2 flows in the range of 600–800 SCCM. A relatively narrow growth window was found for κ-Ga2O3, and best results were achieved for growth temperatures of 600 °C and the O2 flow of 800 SCCM. While phase-pure β-Ga2O3 was prepared, κ-Ga2O3 showed various degrees of parasitic β phase inclusions. X-ray diffraction and transmission electron microscopy confirmed a highly textured structure of β- and κ-Ga2O3 layers resulting from the presence of multiple in-plane domain orientations. Thermal conductivities of 53 nm-thick β-Ga2O3 (2.13 + 0.29/−0.51 W/m K) and 45 nm-thick κ-Ga2O3 (1.23 + 0.22/−0.26 W/m K) were determined by transient thermoreflectance and implications for device applications were assessed. Presented results suggest great potential of heterointegration of Ga2O3 and SiC for improved thermal management and reliability of future Ga2O3-based high power devices.
Original languageEnglish
Article number042708
Number of pages12
JournalJournal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
Issue number4
Early online date8 Jun 2023
Publication statusPublished - 1 Jul 2023

Bibliographical note

Funding Information:
We acknowledge the funding from Slovak Research and Development Agency (Grant Nos. APVV-20-0220 and SK-CN-21-0013), from Slovak Grant Agency VEGA (Grant No. 2/0100/21), and from Slovak Academy of Sciences Dokto Grant No. APP0424. This work was performed during the implementation of the project Building-up Centre for advanced materials application of the Slovak Academy of Sciences, ITMS project code 313021T081 supported by Research & Innovation Operational Programme funded by the ERDF. M.K. was supported by the Royal Academy of Engineering through the Chair in Emerging Technologies Scheme. The thermal characterization was supported as part of the ULTRA, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences at the University of Bristol under Award No. DE-SC0021230.

Publisher Copyright:
© 2023 Author(s).

Structured keywords

  • CDTR


  • Thermal conductivity
  • Field effect transistors
  • Semiconductor growth
  • Crystal structure
  • Epitaxy
  • Thin films
  • Transmission electron microscopy
  • X-ray diffraction
  • Chemical vapor deposition
  • Oxides


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