Berlin 2018 – scientific programme
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DS: Fachverband Dünne Schichten
DS 17: Poster Session I
DS 17.13: Poster
Tuesday, March 13, 2018, 18:15–20:15, Poster B
Investigations of Ge-doped (Al,Ga)2O3 thin films — •A. Werner, H. von Wenckstern, and M. Grundmann — Halbleiterphysik, Universität Leipzig, Leipzig, Germany
Since deep-ultraviolet photo-diodes find wide use in technical applications like flame detection, solar-blind materials like semiconducting Ga2O3 are of peculiar interest. Ga2O3 has a large bandgap of 4.4-4.9 eV which can be enlarged by alloying with Al2O3[1].
The investigated (Al,Ga)2O3 thin films were grown by pulsed laser deposition (PLD) on (00.1) Al2O3. We investigated the influence of the growth parameters such as growth temperature (Tg) and oxygen partial pressures (p(O2)) on the structural, optical and electrical properties of the samples by X-ray diffraction, energy-dispersive X-ray spectroscopy, atomic force microscopy, transmission, and Hall effect measurements, respectively.
The thin films have (2 0 1) orientation and the cation incorporation strongly depends on the deposition parameters.
At a given Tg, the incorporation of Al is favored for lower p(O2) due to higher dissociation energy of the Al-O bond compared to the Ga-O bond. At a given p(O2), the incorporation of Al is favored for higher Tg due to desorption of gallium sub-oxides during growth[2].
Furthermore, we show the influence of Ge-doping on the conductivity.
[1] H. von Wenckstern, Adv. Electron. Mater 3, 1600350 (2017).
[2] P. Vogt and O. Bierwagen, APL Mater. 4, 086112 (2016).