Abstract

Ubiquitous in the modern world, the epitaxial thin film offers a wide range of practical applications in the field of microelectronics, solar industries, optical devices, and catalysis. This thesis deals with studying the growth and characterization of molybdenum nitride (MoN) and various dielectric encapsulated Ru(0001) thin films on single-crystal substrates. The phase-specific and single-crystalline MoN film was grown epitaxially on pre-nitrogen-covered Ru(0001) via physical vapor deposition and characterized by UHV based surface science analytical techniques, including X-ray photoelectron spectroscopy, helium ion scattering spectroscopy, auger electron spectroscopy, and low energy electron diffraction (LEED). The annealing temperature of 700 K was found to result in well-ordered hexagonal films that appear to grow layer-by-layer initially and in registry with the Ru(0001) support. The MoN film starts to decompose via a presumptive N2 recombinative desorption mechanism upon annealing above T = 700 K, which leaves the film in a purely metallic Mo-Ru configuration by T = 1100 K. The oxidation kinetics of hexagonal MoN at ambient conditions predict the complete oxidation of single layer of MoN in ~30 days. Enhanced scattering of electrons at surfaces is a critical factor for the resistivity size-effect observed in single-crystalline nanoscale metals. In this work, we have investigated the surface-dependent effects on resistivity for oxide-capped Ru(0001) films with thickness in the nanometer regime utilizing XPS and LEED to monitor the change in the chemistry and structure of the Ru(0001) interface. The variation in resistivities resulting from presumptive changes in surface structure and chemistry were related to the changes in the Ru surface's specularity (p) for electron scattering in the context of the Fuchs-Sondheimer semi-classical model. In this context, we have demonstrated a fully (reversibly) tunable specularity at the metal interface (from fully specular to fully diffuse), buried under the amorphous oxide dielectrics.

Notes

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Graduation Date

2020

Semester

Fall

Advisor

Kaden, William

Degree

Doctor of Philosophy (Ph.D.)

College

College of Sciences

Department

Physics

Degree Program

Physics

Format

application/pdf

Identifier

CFE0008778;DP0025509

URL

https://purls.library.ucf.edu/go/DP0025509

Language

English

Release Date

6-15-2021

Length of Campus-only Access

None

Access Status

Doctoral Dissertation (Open Access)

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Physics Commons

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