Impact of LT-GaAs layers on crystalline properties of the epitaxial GaAs films grown by MBE on Si substrates

• Published in: Journal of physics. Conference series 2016-08, Vol.741 (1), p.12020
• Main Authors: Petrushkov, M O, Putyato, M A, Gutakovsky, A K, Preobrazhenskii, V V, Loshkarev, I D, Emelyanov, E A, Semyagin, B R, Vasev, A V
• Format: Article
• Language: English
• Subjects: Clusters; Crystal structure; Crystallinity; Electron diffraction; Epitaxial growth; Epitaxial layers; Gallium arsenide; High energy electrons; Low temperature; Molecular beam epitaxy; Nucleation; Physics; Silicon substrates; Thickness; Threading dislocations
• ISSN: 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/741/1/012020

GaAs films with low-temperature GaAs (LT-GaAs) layers were grown by molecular beam epitaxy (MBE) method on vicinal (001) Si substrates oriented 6° off towards [110]. The grown structures were different with the thickness of LT-GaAs layers and its arrangement in the film. The processes of epitaxial layers nucleation and growth were controlled by reflection high energy electron diffraction (RHEED) method. Investigations of crystalline properties of the grown structures were carried out by the methods of X-ray diffraction (XRD) and transmission electron microscopy (TEM). The crystalline perfection of the GaAs films with LT-GaAs layers and the GaAs films without ones was comparable. It was found that in the LT- GaAs Si layers the arsenic clusters are formed, as it occurs in the LT-GaAs GaAs system without dislocation. It is shown that large clusters are formed mainly on the dislocations. However, the clusters have practically no effect on the density and the propagation path of threading dislocations. With increasing thickness of LT-GaAs layer the dislocations are partly bent along the LT-GaAs GaAs interface due to the presence of stresses.