Mechanics Analysis of Semiconductor Nanotube Formation Driven By Residual Mismatch Strain
The intent of this thesis is to investigate the formation mechanics of bi-layer semiconductor nanotubes (SNTs). SNTs are a promising architecture for use in a variety of applications from quantum structures to building blocks in micro- and nano-electro-mechanical systems. Bi-layer SNTs are manufactured using a thin film bending process which relies on the residual stress in the system due to a lattice mismatch between each layer as the driving force for formation from a flat plate into a tube. A recent technique utilizing a photolithographic patterning process has allowed for large scale manufacturability of these tubes. However, when large scale arrays are constructed using this patterning method, inconsistencies can arise in the direction along which tubes form. This investigation centers on identifying key parameters controlling SNT formation in order to identify the source of these inconsistencies. The first objective pursues determining the energetics associated with tube formation and seeks to identify which formation states are thermodynamically preferential. The second objective discusses whether or not the history dependence affects the formation process. It was found that while the enegetics of the process largely dictates the formation characteristics, under special conditions the history dependence in the process may be the source of the inconsistencies seen.
Microtube, Nanotube, Microtube Formaton, Nanotube Formation, Epitaxial Mismatch Strain, Bilayer Nanotube, Bilayer Microtube
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign