Magnesium-doped GaAs and Alx Ga1−x As by molecular beam epitaxy

Abstract

Molecular beam epitaxy (MBE) of Mg‐doped GaAs and Al_xGa_1−xAs layers was studied in situ by high‐energy electron diffraction and Auger spectrometry. The analysis of the incorporation of Mg into the layers was studied with a Cameca (IMS 300) ion‐sputtering mass spectrometer and by Hall‐effect determination. It has been demonstrated that the sticking coefficient of Mg increases very rapidly (almost 3 orders of magnitude) under the specific conditions of this experiment when x increases from zero to 0.2, and that controlled p‐type doping of GaAs and Al_xGa_1−xAs with Mg during MBE is possible. A new surface structure (001)−2×2‐Mg is observed when a Mg beam impinges on a GaAs or Al_xGa_1−xAs surface.