Dynamic study of the surfaces of (001) gallium arsenide in metal-organic vapor-phase epitaxy during arsenic desorption

被引：0

作者：

Pristovsek, M. ^{[1
]}

Trepk, T. ^{[1
]}

Klein, M. ^{[1
]}

Zettler, J.-T. ^{[1
]}

Richter, W. ^{[1
]}

机构：

[1] Technische Universität Berlin, PN6-1, Inst. für Festkörperphysik, Hardenbergstraße 36, D-10623 Berlin, Germany

来源：

| 1600年 / American Institute of Physics Inc.卷 / 87期

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摘要：

We have investigated by reflectance anisotropy spectroscopy the arsenic desorption from GaAs (001) at various temperatures in metal-organic vapor-phase epitaxy to obtain reaction orders and activation energies. The highest arsenic coverage, found at low temperatures with arsine stabilization, corresponds to a (4×3) reconstruction. Without arsine, arsenic starts to desorb and less arsenic-rich reconstructions are observed, depending on temperature: c(4×4) (below 800 K), β2(2×4) (below 920 K), α(2×4), and only with hydrogen carrier gas finally (4×2) (above 950 K). Above 920 K the reaction order differs in hydrogen and nitrogen atmosphere, probably due to an etching effect of hydrogen radicals. The five different desorption processes show either a first-or zero-order time dependence. First order is related to the desorption from the terraces and zero order to desorption from the steps (or kinks) on the surfaces. The activation energies for all processes are around 2.5 eV. This energy is, therefore, assumed to be the activation energy for the removal of an arsenic dimer from the surface. © 2000 American Institute of Physics.

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