Senior Theses


This thesis has been designated as Linfield Access only. It is available only to members of the Linfield community with a valid CatNet ID and password. We apologize for any inconvenience this might cause.

Off-campus Linfield users: To download this thesis, please click the button for Off-Campus Download (Linfield users only).

Non-Linfield University users: Please talk to your local librarian about requesting this thesis through interlibrary loan.

Publication Date

5-2020

Document Type

Thesis (Linfield Access)

Degree Name

Bachelor of Science in Physics

Department

Physics

Faculty Advisor(s)

Jennifer Heath (Thesis Advisor)
Joelle Murray & Michael Crosser (Committee Members)

Subject Categories

Electrical and Computer Engineering | Electronic Devices and Semiconductor Manufacturing | Engineering Physics | Materials Science and Engineering | Physics | Power and Energy | Semiconductor and Optical Materials

Abstract

In a 2D field effect transistor (FET), the electrical properties of the channel are modulated using a gate voltage. The electrostatic doping of the channel and the contact resistance of the interacting layers both contribute to the overall device conductivity, which plateaus above a certain gate voltage. Other factors, such as surface cleanliness and microscopic details of the films, also influence the conductivity as can be deduced from variations between multiple devices. In this study, we explore the ability of Kelvin probe force microscopy (KPFM) to separate the different factors influencing overall device conductivity. By applying a potential bias to a simple device, we build confidence in the linear response and reproducibility of the KPFM technique. We then directly visualize the uniformity of the surfaces, the potential barriers between layers, and the characteristics of the WSe2 film as a function of the applied voltage. These data deepen our understanding of device potentials and conduction in 2D FETs.

Share

COinS