A1 Refereed original research article in a scientific journal
Surface doping of GaxIn1−xAs semiconductor crystals with magnesium
Authors: Yasir M, Mäkelä J, Koiva D, Tuominen M, Dahl J, Lehtiö J, Kuzmin M, Rad ZJ, Punkkinen M, Laukkanen P, Kokko K, Polojärvi V, Lyytikäinen J, Tukiainen A, Guina M
Publisher: Elsevier
Publication year: 2018
Journal: Materialia
Journal name in source: Materialia
Volume: 2
First page : 33
Last page: 36
ISSN: 2589-1529
DOI: https://doi.org/10.1016/j.mtla.2018.05.008(external)
Web address : http://www.sciencedirect.com/science/article/pii/S258915291830019X(external)
Abstract
Effects of magnesium (Mg) alloying of GaxIn1−xAs(100) semiconductor surfaces have been investigated by low-energy electron diffraction, scanning tunneling microscopy/spectroscopy, and responsivity analysis of an infrared-detector component. In particular, the formation of an unusual Mg-induced (2 × 1) structure on GaAs(100) surfaces is found when depositing 1–3 monolayers of Mg on a cleaned GaAs(100) surface followed by annealing the sample in vacuum conditions at up to 500 °C. Concomitantly, the spectroscopy data show that the Fermi-level shifts toward valence band at the surface, indicating p-type doping of a surface part of GaAs due to Mg incorporation into the semiconductor. This surface-doping effect is also present in a test GaxIn1−xAs infrared detector, leading to increase in the detector responsivity. This beneficial effect of Mg-induced p-type doping is explained by a band-bending induced transfer of electrons away from a defect-rich top interface.
Effects of magnesium (Mg) alloying of GaxIn1−xAs(100) semiconductor surfaces have been investigated by low-energy electron diffraction, scanning tunneling microscopy/spectroscopy, and responsivity analysis of an infrared-detector component. In particular, the formation of an unusual Mg-induced (2 × 1) structure on GaAs(100) surfaces is found when depositing 1–3 monolayers of Mg on a cleaned GaAs(100) surface followed by annealing the sample in vacuum conditions at up to 500 °C. Concomitantly, the spectroscopy data show that the Fermi-level shifts toward valence band at the surface, indicating p-type doping of a surface part of GaAs due to Mg incorporation into the semiconductor. This surface-doping effect is also present in a test GaxIn1−xAs infrared detector, leading to increase in the detector responsivity. This beneficial effect of Mg-induced p-type doping is explained by a band-bending induced transfer of electrons away from a defect-rich top interface.
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