Characterization of MOCVD-grown InP on [formula omitted]

• Published in: Surface science Vol. 326; no. 3; pp. 209 - 217
• Main Authors: Reaves, C.M., Bressler-Hill, V., Varma, S., Weinberg, W.H., DenBaars, S.P.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.1995
• Subjects: Atomic force microscopy; Chemical vapor deposition; Electron microscopy; Indium phosphide; Self-assembly; Surface structure; Atomic force microscopy; Self-assembly; Electron microscopy; Chemical vapor deposition; Indium phosphide; Surface structure
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(94)00755-1

Atomic force microscopy and transmission electron microscopy have been used to investigate the metalorganic chemical vapor deposition of InP on nominally flat InGaP GaAs(001) substrates. From a detailed structural analysis of the deposited InP, we observe coherent Stranski-Krastanov growth, i.e., after the initial formation of a two-dimensional layer, two types of coherently strained islands appear above a defined thickness. At higher coverages a third type of larger, incoherent and defected island is observed. The two types of coherently strained islands can be characterized by their distinct sizes. For low coverages the coherently strained islands possess irregular dimensions in the plane of the substrate and have a maximum height of 6 nm. At higher coverages the second type of coherently strained islands appears. These are cap-shaped and have a rather narrow distribution of base diameter (120 ± 10 nm) and height (22.5 ± 2.5 nm). An appreciable density of incoherent and defected relaxed islands also becomes evident at increased coverages. These have a hexagonal shape exposing clear facets and are elongated along the [110] crystallographic direction of the substrate.