Berlin 2005 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 13: III-V Halbleiter II

HL 13.4: Vortrag

Freitag, 4. März 2005, 15:45–16:00, TU P-N202

Exchange reactions of As and N on GaAs surfaces — •R. Ehlert¹, S.J. Simon¹, F. Poser¹, N. Esser², P. Vogt¹, and W. Richter¹ — ¹Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin — ²Institute for Analytical Science, Dept. Berlin, Albert-Einstein Str. 9, 12489 Berlin

GaAs_1−xN_x is a promising material for light emitting devices operating in a spectral range from 1.3 -1.55 µm . Understanding the nitrogen incorporation mechanisms in GaAs_1−xN_x is crucial for optimization of growth conditions.

We present comparative in-situ RAS studies of GaAs_1−xN_x under MOVPE condition and in UHV for samples with a nitrogen content of up to 5 % . Samples are grown in MOVPE by using TMGa, TBAs and TBHy as precursors or prepared by nitridation of GaAs surfaces. Upon nitridation a change of RAS spectra from the GaAs(2×4) to the GaAsN (3×3)-like is observed. After growth the samples are capped with an amorphous As-capping layer, transferred to UHV and decapped by annealing. Alternatively, samples were prepared by nitridation of clean GaAs(001) surfaces using ammonia as a nitrogen source. RHEED, RAS, STM and SXPS are used to measure surface properties.