Regensburg 2022 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 25: Poster 1
HL 25.33: Poster
Wednesday, September 7, 2022, 18:00–20:00, P2
Phonon Transport in Thin Homoepitaxial β-Ga2O3 Films — •Robin Ahrling1, Olivio Chiatti1, Rüdiger Mitdank1, Zbigniew Galazka2, Andreas Popp2, and Saskia F. Fischer1 — 1Novel Materials Group, Humboldt-Universität zu Berlin, 10099 Berlin, Germany — 2Leibniz Institute for Crystal Growth, 12489 Berlin, Germany
As a wide-band gap semiconductor with a high breakthrough field, gallium oxide (Ga2O3) has shown to be a promising material for applications in high power electronics. However, due to the materials low thermal conductivity [1,2] heat dissipation is a challenge for future device applications. By photolithography, magnetron sputtering and subsequent liftoff we prepare structures for investigating the thermal transport in the bulk Ga2O3 substrate and the thin homoepitaxial β-Ga2O3 films by applying the 2-ω and 3-ω measurement techniques.
For the substrate, we observe a dominance of phonon-phonon Umklapp scattering for high temperatures (>90 K) and a combination of point defect scattering and boundary effects for low temperatures. The phonon mean free path reaches a limit for low temperatures that can be explained with the crystal thickness. We aim to investigate the thermal transport exclusively in the thin films by producing sub-µm heater widths using electron beam lithography and performing measurements at higher frequencies.
[1] M. Handwerg et al., Semicond. Sci. Technol. 30, (2015) 024006
[2] M. Handwerg et al., Semicond. Sci. Technol. 31, (2016) 125006