Structure of interfaces in GaN/AlN and Ge/Si multilayered heterosystems by XAFS spectroscopy

31st International Conference on Equations of State for Matter

Erenburg, S.B.^1,2 ; Trubina, S.V.^1 ; Zhuravlev, K.S.^3,4 ; Malin, T.V.^3 ; Zinovyev, V.A.^3 ; Dvurechenskii, A.V.^3,4 ; Kuchinskaya, P.A.^3 ; Kvashnina, K.O.^5,6

Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentyev Avenue 3, Novosibirsk

630090, Russia^1

Budker Institute of Nuclear Physics, Siberian Branch, Russian Academy of Sciences, Lavrentyev Avenue 11, Novosibirsk

630090, Russia^2

Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Lavrentyev Avenue 13, Novosibirsk

630090, Russia^3

Novosibirsk State University, Pirogova Street 2, Novosibirsk

630090, Russia^4

European Synchrotron Radiation Facilities, Avenue des Martyrs 71, Grenoble

38043, France^5

Helmholtzzentrum Dresden-Rossendorf, Institute of Resource Ecology, P.O. Box 510119, Dresden

01314, Germany^6

关键词: Coordination number;    Debye Waller factor;    Degree of intermixing;    Ge concentrations;    Hetero interfaces;    Inter-atomic distances;    Local structure;    Microstructural parameters;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/774/1/012128/pdf
DOI  :  10.1088/1742-6596/774/1/012128

来源: IOP

【 摘 要 】

III-nitride heterostructures in the form of multilayered quantum wells (MQWs) or quantum dots (QDs) and interacting Ge QDs ("quantum molecules") are promising candidates for high-speed intersubband (ISB) optical devices relying on the quantum confinement of electrons. Microstructural parameters (interatomic distances, coordination numbers, and Debye-Waller factors) were determined by means of EXAFS spectroscopy based on the Synchrotron Radiation, and the relationship between the variations in these parameters and the morphology of superlattices and symmetric assembles of QDs were established. The EXAFS technique has been used to study the local structure of thin hexagonal GaN/AlN MQWs grown by ammonia MBE at different temperatures. It is shown that the heterointerface intermixing leads to a decrease in the Ga-Al interatomic distance and the Ga-Ga coordination number in MQWs. The degree of intermixing in the boundary layers rises from 30% to 40% with increase of the growth temperature from 795 to 895 °C. It was found that in the first phase of quantum molecules growth Ge atoms concentration is 25%. With further growth (deposition of the base layers) Ge concentration increases up to 35-45%, depending on the temperature (from 610 to 550 °C) of deposition.