Electrical properties of Mg‐doped GaN and Al x Ga 1–x N

Autor: Boris Ya. Ber, V. N. Jmerik, Nataliya M. Shmidt, A. M. Mizerov, Stefan Ivanov, Dmitry Yu. Kasantsev, T. A. Komissarova
Rok vydání: 2009
Předmět:
Zdroj: physica status solidi c. 6
ISSN: 1610-1642
1862-6351
DOI: 10.1002/pssc.200880939
Popis: We report on plasma-assisted molecular beam epitaxy (PA MBE) growth of Mg-doped GaN and AlxGa1–xN (x = 0.15 and 0.42) layers on c-sapphire (N-polarity) and studies of their electrical properties as functions of growth temperature, Mg flux and alloy composition. P-type conductivity was examined to follow the general trends defined for MOVPE and Ga-polar GaN layers grown by metal-organic vapor phase epitaxy and MBE. The achieved hole concentration in the GaN:Mg layers measured by Hall effect and C-V is in the range of (0.3 – 2)×1018 cm–3 at Mg BEP changing within (2 – 7)×10–9 Torr. Hall hole concentration p = 4×1017 cm–3 and mobility μ = 1.4 cm2/Vs at 250 K have been measured for the first time in AlxGa1–xN with x > 0.4 grown by PA MBE. Acceptor activation energies for GaN:Mg and Al0.15Ga0.85N:Mg epilayers were determined from temperature dependences of resistivity at T ≥ 300 K to be EA ∼ 100 meV and 220 meV, respectively. Hopping mechanism of conductivity was confirmed for AlxGa1–xN:Mg layers studied at T ≤ 300 K. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Databáze: OpenAIRE
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