Intensity variations of reflection high-energy electron diffraction during atomic layer epitaxial growth and sublimation of Zn chalcogenides

Abstract

Intensity variations of reflection high-energy electron diffraction (RHEED) patterns during atomic layer epitaxy (ALE) growth of Zn chalcogenides have been investigated. The specular beam intensity has been found to vary exponentially with growth time. It is shown that these variations correspond to changes from the Zn to the Se surface reconstruction, and using the exponential time constant, the adsorption time of a monolayer is calculated. The specular beam intensity also varies exponentially with time during the sublimation process of the surface chalcogen layer at rather higher substrate temperatures. The adsorption time constants are investigated as a function of K-cell and substrate temperature, and the desorption time constants are investigated as a function of substrate temperature. It is possible to investigate the growth dynamics of ALE of Zn chalcogenides from the RHEED intensity variations.