Anion exchange at the interfaces of mixed anion III-V heterostructures grown by molecular beam epitaxy

Anion exchange;Segregation;Diffusion

Brown, Terence D. ; Electrical and Computer Engineering

University:Georgia Institute of Technology

Department:Electrical and Computer Engineering

关键词: Anion exchange;    Segregation;    Diffusion;   

Others  :  https://smartech.gatech.edu/bitstream/1853/5279/1/brown_terence_d_200312_phd.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

The objective of this research was to investigate the microscopic processes occurring at the interfaces of mixed anion III-V heterostructures grown by molecular beam epitaxy (MBE).In particular, efforts were made to characterize the dominant chemical and physical mechanisms that lead to anion exchange and to develop semi-empirical models capable of predicting the atomic scale structure and composition at the interfaces of mixed anion heterostructures for the As/P and Sb/As material systems.This research considers the MBE growth of 20-period superlattices (SLs) formed by allowing a dissimilar anion flux to impinge on a static group-V stabilized surface.Statistical experimental design was used to determine the effects of substrate temperature, V/III growth flux ratio, and anion exposure time on the anion exchange process.The superlattice structures were analyzed via high resolution x-ray diffraction (HRXRD) and simulation, RHEED analysis, x-ray photoelectron spectroscopy (XPS), and other techniques, which allowed for the determination of both chemical composition and atomic structure at the interfaces.Finally, a semi-empirical hybrid neural network was developed that quantifies the effects of MBE growth processes at the interfaces of mixed anion III-V heterostructures by incorporating a first principles kinetic model with back-propagation neural networks.