RHEED oscillations at special diffraction conditions

• Published in: Surface science 1993-12, Vol.298 (2), p.293-298
• Main Authors: Maksym, P.A., Mitura, Z., Knibb, M.G.
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Physics; Solid surfaces and solid-solid interfaces; Surface structure and topography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(93)90041-H

It is suggested that analysis of RHEED intensity oscillations can be simplified when diffraction conditions are chosen appropriately and two cases are presented as supporting evidence. The first is an out-of-phase condition where the specular reflection from the substrate is very weak. At this condition the oscillations can be described by a kinematic calculation which is modified to take account of refraction. The second case occurs when electrons are incident at glancing angles less than about 1°. Under this condition the oscillations can have a double-minimum structure with one minimum at very small coverages of the growing layer and a second minimum at higher coverages. The minima occur because the growing layer becomes near-transparent at certain critical strengths of the laterally averaged scattering potential. This is illustrated with numerical results for lead and silver.