Date of Award
12-4-2015
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Applied Science
First Advisor
Hye Won Seo
Abstract
Gallium nitride (GaN) nanorods have been grown on Silicon substrate by plasma-assisted molecular beam epitaxy (PAMBE). An amorphous and inhomogeneous interfacial silicon nitride (SixNy) layer is unintentionally formed at the initial stage of the GaN growth due to the high affinity between Si and N. The GaN cluster formation on uncontrolled SixNy layer occurs not only tilted but also defect-included such as stacking faults and threading dislocations. These defects mostly would be kept and carried throughout the growth. In this work, we studied the effect of crystal properties of SixNy layer on GaN nanorod quality by varying the nitridation parameters such as temperature, plasma power, post annealing conditions during the PAMBE growth. The morphological, crystalline and optical properties of SixNy layer was investigated by scanning electron microscopy (SEM), reflection high energy electron diffraction (RHEED), atomic force microscopy (AFM), x-ray photoelectron spectroscopy (XPS), photoluminescence (PL) methods. By optimizing nitridation conditions, we have achieved the GaN nanorods much more aligned relative to the substrate normal with better crystal and optical properties. It is because the initial growth on this SixNy layer was under-controlled and starts with less defects.
Recommended Citation
Keles, Filiz, "Silicon Nitride Interfacial Layer Effect on Gallium Nitride Nanorod Growth" (2015). Theses and Dissertations. 653.
https://research.ualr.edu/etd/653
