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.
| Identifer | oai:union.ndltd.org:GATECH/oai:smartech.gatech.edu:1853/5279 |
| Date | 25 November 2003 |
| Creators | Brown, Terence D. |
| Publisher | Georgia Institute of Technology |
| Source Sets | Georgia Tech Electronic Thesis and Dissertation Archive |
| Language | en_US |
| Detected Language | English |
| Type | Dissertation |
| Format | 6934067 bytes, application/pdf |
Page generated in 0.0016 seconds