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The Czochralski method is one of the leading research and industrial crystal growth technologies that enables to obtain large diameter single crystals of high structural quality at low production costs per volume unit. A possibility of obtaining bulk β-Ga2O3 single crystals by the Czochralski method expands the diversity of growth technologies for this compound towards large volumes and high quality suitable for epitaxial growth of layers and device fabrication. Ga2O3 is, however, thermally unstable at high temperatures and tends to decompose that has a high impact on the growth process, size, and structural quality of obtained crystals. Additionally, the growth process is also affected by electrical/optical properties of a growing β-Ga2O3 crystal. Ga2O3 thermodynamics combined with new technical solutions allowed to obtain 2-inch diameter cylindrical single crystals of β-Ga2O3 of high structural quality with further scale-up capabilities. Czochralski-grown bulk β-Ga2O3 single crystals can be easily doped with a diversity of elements to tune their electrical and optical properties. The bulk β-Ga2O3 single crystals can be obtained either as electrical insulators or semiconductors both with a high transparency in the UV and visible spectral regions.
KeywordsCzochralski method Iridium crucible Iridium oxidation Bulk β-Ga2O3 single crystal Structural quality Thermodynamics Thermal stability Decomposition Growth atmosphere Oxygen concentration Free carrier absorption Doping Segregation coefficient Ultra-wide bandgap semiconductor Annealing
I would like to express my gratitude to Dr. Detlef Klimm, Dr. Steffen Ganschow, Dr. Klaus Irmscher for helpful discussions. This work was partly performed in the framework of GraFOx, a Leibniz-Science Campus partially funded by the Leibniz Association, Germany.
- 1.J. Czochralski, Z. Phys. Chem. 92, 219 (1918)Google Scholar
- 4.E. Grüneisen, E. Goens, Phys. Z. 24, 506 (1923)Google Scholar
- 7.J.B. Little, G.K. Teal, Phys. Rev. 78, 647 (1950)Google Scholar
- 10.D.A. Petrov, V.S. Zemskov, Rost Kristallov 1, 262 (1957)Google Scholar
- 11.R. Gremmelmaier, O. Madelung, Z. Naturforsch. 8A, 333 (1953)Google Scholar
- 12.R. Gremmelmaier, Z. Naturforsch. 11A, 511 (1956)Google Scholar
- 17.V.I. Vasil’tsiv, Y. Zakarko, Zh. Prikl. Spektrosk. 39, 423 (1983)Google Scholar
- 21.Z. Galazka, R. Uecker, D. Klimm, M. Bickermann, EP patent 3242965B1, 2019Google Scholar
- 22.Z. Galazka R. Uecker, D. Klimm, K. Irmscher, M. Naumann, M. Pietsch, A. Kwasniewski, R. Bertram, S. Ganschow, M. Bickermann, ECS J. Solid State Sci. Technol. 6, Q3007 (2017)Google Scholar
- 27.Z. Galazka, K. Irmscher, R. Schewski, I. M. Hanke, M. Pietsch, S. Ganschow, D. Klimm, A. Dittmar, A. Fiedler, T. Schroeder, M. Bickermann, J. Cryst. Growth 529, 125297 (2020)Google Scholar
- 28.Z. Galazka, R. Schewski, K. Irmscher, W. Drozdowski, M. E. Witkowski, M. Makowski, A. J. Wojtowicz, I. M. Hanke, M. Pietsch, T. Schulz, D. Klimm, S. Ganschow, A. Dittmar, A. Fiedler, T. Schroeder, M. Bickermann, J. Alloy. Compd. in print, 152842 (2019)Google Scholar