Engineering Commons^™

Application Of In Situ And Ex Situ Characterization Of Atomic Layer Deposition Processes For Gallium Phosphide And Sodium Fluoride, Sara Rose Kuraitis

Boise State University Theses and Dissertations

Atomic layer deposition (ALD) is a vapor deposition technique for synthesizing thin films with nanometer thickness control. ALD films are deposited on a substrate surface in a cyclic layer-by-layer fashion utilizing alternating doses of highly reactive chemical precursors. Precursors are selected to undergo self-limiting chemical reactions with the surface, and desired film thickness is achieved by varying the number of ALD cycles accordingly. Optimization of ALD process parameters and precursor chemistry enables conformal coating of arbitrary substrate geometries, including high aspect ratio features such as trenches. In the decades since its introduction, ALD has been used for applications across many …

First-Principles Studies Of Nucleation Of Atomic-Layered Molybdenum Disulfide By Atomic Layer Deposition, Matthew Lawson

Boise State University Theses and Dissertations

This dissertation implements first-principles calculations to understand the nucleation mechanisms for atomic layer deposition (ALD) of molybdenum disulfide (MoS₂) using MoF₆ and H₂S precursors. ALD is a self-limiting process that can deposit a range of materials at the nanoscale, while maintaining chemical stoichiometry, atomic scale thickness control, and can conform to high-aspect ratio substrate designs. ALD is extremely sensitive to surface chemistry and morphology; therefore, it is critical to understand how these factors control deposition.

Density functional theory (DFT) was used to understand what factors can control the nucleation for ALD of MoS₂ using …

Molybdenum Sulfide Prepared By Atomic Layer Deposition: Synthesis And Characterization, Steven Payonk Letourneau

Boise State University Theses and Dissertations

Molybdenum disulfide (MoS₂) is the prototypical two-dimensional (2D) semiconductor. Like graphite, it has a layered structure containing weak van der Waals bonding between layers, while exhibiting strong covalent bonding within layers. The weak secondary bonding allows for isolation of these 2D materials to single layers, like graphene. While bulk MoS₂ is an indirect band gap semiconductor with a band gap of ~1.3 eV, monolayer MoS₂ exhibits a direct band gap of ~1.8 eV, which is an attractive property for many opto-electronic applications. Atomic layer deposition (ALD) has been used to grow amorphous films of MoS_{2 …}