Anna K. Benton
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The purpose of this investigation is to control the formation of atomically thin metal films of transition metals on silicon wafers with a 200 nm oxide layer. Metals have physical characteristics that are dependent on the thickness and structure of the material. The thickness and the structure of the material change depending on the conditions of metal deposition. By varying the metal deposition conditions, the desired physical characteristics, such as roughness and crystalline domain size, can be attained. This project focuses on depositing a transition metal film using a sputtering chamber at different growth conditions using low power, medium power, and high power. Film thickness and structure were observed using an atomic force microscope (AFM). Surface features were observed using a scanning electron microscope (SEM). Conductivity data was used to indicate film structure. The metal films will then be exposed to a vapor containing sulfur or selenium to create thin heterostructures of transition metal dichalcogenides (TMDs). The heterostructure films will then be characterized using an AFM, SEM and Raman Spectroscopy. Once the relationship between metal film structure and reactivity with chalcogen vapors is understood, different transition metal films will be deposited sequentially to form a bilayer of two transition metals. After film growth, the bilayers will be observed using an AFM and SEM. Conductivity data will indicate film structure. The bilayer films will be exposed to vapor containing sulfur or selenium to create two layers of TMDs. One of the applications of this project is to be able to tune the electronic and optical properties of semiconductors by varying the stacking pattern of many TMD layers. This will allow desirable band gaps to be achieved for transistors and sensors. Stacking two layers is the first step in understanding how effective this novel approach for development of synthetic superlattices can be.
Primary Advisor's Department
Chemical and Materials Engineering
Stander Symposium project, School of Engineering
"Metal Layer Architectures for 2D TMD Heterostructures" (2020). Stander Symposium Projects. 1898.