A1 Journal article – refereed
Surface doping of GaxIn1−xAs semiconductor crystals with magnesium

List of 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 name in source: Materialia
Volume number: 2
ISSN: 2589-1529

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.

Last updated on 2019-29-01 at 13:22