Carrier removal rates in 1.1 MeV proton irradiated α-Ga 2 O 3 (Sn)

• Published in: Journal of physics. D, Applied physics Applied physics, 2023-07, Vol.56 (30), p.305103
• Main Authors: Polyakov, A Y, Nikolaev, V I, Pechnikov, A I, Lagov, P B, Shchemerov, I V, Vasilev, A A, Chernykh, A V, Kochkova, A I, Guzilova, L, Pavlov, Yu S, Kulevoy, T V, Doroshkevich, A S, Isaev, R Sh, Panichkin, A V, Pearton, S J
• Format: Article
• Language: English
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/1361-6463/acd06b

Films of α -Ga 2 O 3 (Sn) grown by halide vapor phase epitaxy on sapphire with donor densities in the range 5 × 10 15 –8.4 × 10 19 cm −3 were irradiated at 25 °C with 1.1 MeV protons to fluences from 10 13 to 10 16 cm −2 . For the lowest doped samples, the carrier removal rate was ∼35 cm −1 at 10 14 cm −2 and ∼1.3 cm −1 for 10 15 cm −2 proton fluence. The observed removal rate could be accounted for by introduction of deep acceptors with optical ionization energies of 2 eV, 2.8 eV and 3.1 eV. For samples doped at 4 × 10 18 cm −3 , the initial electron removal rate was 5 × 10 3 cm −1 for 10 15 cm −2 fluence and ∼300 cm −1 for 10 16 cm −2 fluence. The same deep acceptors were observed in photocapacitance spectra, but their introduction rate was orders of magnitude lower than the carrier removal rate. For the heaviest doped samples, the electron removal rate was close to that for the 4 × 10 18 cm −3 sample. The radiation tolerance of lightly doped α -Ga 2 O 3 is higher than for similarly doped β -Ga 2 O 3 layers.