The two- to three-dimensional growth transition of InAs/GaAs epitaxy layer studied by reflectance difference spectroscopy

Abstract

In this work, we have adopted reflectance difference spectroscopy to study the evolution of InAs layer grown at different temperatures in GaAs matrix. Associated with the two- to three-dimensional growth transition of InAs layer, the transition energies and the in-plane optical anisotropy of InAs wetting layer exhibit abrupt changes. This provides a new way to decide the critical thickness hc for the growth transition. The obtained hcs are compared with those determined by atomic force microscope measurement, and discrepancy is found at high temperatures. The origin of the difference is clarified and the variations in hc with temperature are further discussed.