III-nitride semiconductors have garnered significant attention due to their diverse applications in the fields of optics and electronics. As GaN-based visible light-emitting diodes (LEDs) and laser technologies continue to
advance, there has been a surge of interest in the development of ultraviolet (UV) devices. In order to explore the UV range, extensive research has been conducted on BN-based materials and their alloys with conventional III-nitrides, driven by the quest for materials exhibiting larger bandgaps and enhanced refractive index contrast. Additionally, the incorporation of boron into III-nitrides through alloying provides a promising avenue for effectively modulating lattice parameters and manipulating the crystalline structure. This offers a novel approach for strain engineering, lattice matching, and structural manipulation, facilitating the optimization of device performance and expanding the capabilities of III-nitride semiconductors in the realm of UV device development.
In this work, we optimize and investigate the epitaxial growth of BGaN using metalorganic chemical vapor deposition, and characterize the physical and electronic properties of the grown films using several techniques such as X-ray diffraction, atomic force microscopy, UV-Visible spectroscopy, X-ray Photoelectron Spectroscopy (XPS), electron energy loss spectroscopy (EELS) and more.
We have explored different metalorganic chemical vapor deposition techniques —such as continuous growth and pulsed-flow modulation, high temperature and low temperature growths, hydrogen-containing and hydrogen-free growths, trimethylgallium (TMG) and triethylgallium (TEG) sourced growths, Triethylborane (TEB) and borazine (BRZN) sourced growths— to grow BGaN alloys. Samples grown using continuous-flow method, low temperatures, TEG source and hydrogen-free carrier gas show higher boron content and better crystalline quality when having TEB as a boron source. BRZN is used to reduce carbon impurities for the purpose of film doping. With BRZN, TMG was found as a preferred gallium source.
Additionally, we have characterized the electronic properties of the grown films in details using XPS, EELS and other related techniques. We have studied the band offset of BGaN with AlN using traditional methods. Furthermore, we have developed a statistical technique to find small offsets at interfaces at the precision of the measuring instrument.
| Identifer | oai:union.ndltd.org:kaust.edu.sa/oai:repository.kaust.edu.sa:10754/693432 |
| Date | 02 May 2023 |
| Creators | AlQatari, Feras S. |
| Contributors | Li, Xiaohang, Physical Science and Engineering (PSE) Division, Roqan, Iman S., Elatab, Nazek, Parbrook, Peter |
| Source Sets | King Abdullah University of Science and Technology |
| Language | English |
| Detected Language | English |
| Type | Dissertation |
| Relation | N/A |
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