Details

Autor(en) / Beteiligte

• Komninou, Ph
• Gladkov, P.
• Karakostas, Th
• Pangrác, J.
• Pacherová, O.
• Vaniš, J.
• Hulicius, E.

Titel

Structural and photoluminescent properties of low temperature InAs buffer layer grown by MOVPE on GaAs substrates

Ist Teil von

• Journal of crystal growth, 2014-06, Vol.396, p.54-60

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2014

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Epitaxial growth of InAs on semi-insulating GaAs was a subject of various attempts to reduce the influence of the ~7% lattice mismatch on the InAs layer properties. The most cost effective and promising method appears to be the growth of low temperature buffer (LTB) InAs layer at ~400°C followed by a thick InAs layer at ~600°C. There is a scarcity of available information about the structural properties of the LTB layers, their background conductivity type and level of doping. We have found that a predominant part of the threading dislocations generated at the interface annihilate within the first 400nm. The average misfit dislocation spacing is 6.15nm, proving that the LTB InAs/GaAs interface is nearly completely relaxed. XRD measurements have revealed a well pronounced deformation decrease in the LTB layers for thicknesses above 300nm. The LTB InAs layer is n-type with carrier concentration of the order of 5×1016cm−3 and can be additionally doped with Te and hence can serve as a bottom contact layer. The morphology of unintentionally doped InAs layer grown at 600°C upon the LTB shows sub-nanometer flatness and carrier concentration of the order of 5×1015cm−3. •Structural properties of InAs buffer layer grown by MOCVD on GaAs at 400°C were studied.•Electron transmission microscopy and XRD verify that the GaAs/InAs interface is nearly completely relaxed and that the optimized buffer layer thickness for a subsequent InAs growth at 600°C is 0.4μm.•The buffer layer exhibits n-type conductivity with carrier concentration of ~5×1016cm−3.•InAs layer grown at 600°C on top of 0.4μm buffer layer is mirror like with sub-nanometer morphology and carrier concentration of ~5×1015cm−3.