Глубокая рентгеновская рефлектометрия сверхмногопериодных A3B5-структур с квантовыми ямами, выращиваемых методом молекулярно-пучковой эпитаксии

Abstract

We studied the elastically strained AlGaAs/GaAs super-multiperiod (SMP – 100–1000 periods) superlattices with different degrees of doping and a small difference in the period thickness. The proposed characterization technique, consisting of the matched application of the deep X-ray reflectometry method, based on a rigorous calculation method, as well as the well-known high-resolution X-ray reflectometry method, made it possible to study 100-period structures with 2-nm wide Al0.3Ga0.7As barriers and 10-nm wide GaAs wells and to determine the layer thicknesses and the blurring of interfaces with high accuracy. It can be considered as the first step in the further analysis of thick structures using bright sources of synchrotron radiation. The difference between the expected and obtained, as a result of restoration by the proposed method, values of the layer thicknesses was several percent, including for samples with a high degree of doping (up to 10^18 cm^−3). All SMP structures are characterized by sharp interfaces with a standard deviation of the order of 0.1 nm. Based on the thickness data obtained, it is possible to accurately determine the composition of the layers using high-resolution X-ray diffractometry.