BIO

Aloha, my name is Thomas Lockhart, I am from Hilo, Hawaii, and I am currently a sophomore at Florida State University as a chemical engineering major. Through the UROP program, I was able to take part in a research project as a research assistant to Kylie E. Van Meter and was exposed to the numerous components of research from experimenting, data processing, and presenting. This experience inspired me to continue participating in undergraduate research and pursue a future graduate degree in chemical engineering. I enjoy exploring what Tallahassee and Florida have to offer in my future in both education and career. Although Florida is far from home, the beaches and the outdoors have never ceased to remind me of home.

The Effects of Substrate Bias Voltage on the Tribological Properties of Plasma-Enhanced Atomic Layer-Deposited Nitride Thin Films

Abstract

Plasma Enhanced-Atomic Layer deposition (PE-ALD) is a method of creating thin films (<100 nm) through self-limiting chemical surface reactions. During the deposition process, parameters such as substrate bias voltage can have a significant impact on the material properties of the films. The purpose of this project is to determine the correlation between the radiofrequency voltage applied to the substrate during deposition and the films’ tribological properties. The samples used in this project are Titanium Vanadium Nitride films (TiVN) layered onto a silicon wafer substrate. It was predicted that the higher the voltage used, the smaller the wear rate up until the properties plateau, as seen in other material systems. The samples were created using radiofrequency plasma at 5, 10, 20, 30, and 40 Volts. These samples were tested in a linearly reciprocating tribometer in a Nitrogen gas environment to limit any potential chemical reactions with the atmosphere. Friction data was recorded via tribometer, while the wear rate was calculated using surface scans. The data reflects that the 5V and 10V samples had fairly high wear rates and friction coefficients, while the 20V sample had the lowest steady-state wear rate and the second-lowest friction coefficient, the 30V sample reflected slightly higher properties than the 20V, the 40V sample had the highest steady-state wear rate yet the lowest friction coefficient. While this result does align with earlier predictions further research is required to determine why radiofrequency voltages above 20V negatively affect the friction coefficient and wear rates of PE-ALD TiVN thin films.

Keywords: Thin Films, Tribology, Material Science