System innovations for aerosol MOCVD of YBCO superconducting thin films |
Posted on:1998-03-22 | Degree:Ph.D | Type:Dissertation |
University:University of Arkansas | Candidate:Nelms, David Martin | Full Text:PDF |
GTID:1462390014476401 | Subject:Engineering |
Abstract/Summary: | |
System innovations were developed for metallo-organic chemical vapor deposition (MOCVD) in order to achieve two main objectives: to fully characterize a novel feed system while and to demonstrate uniform, superconducting thin films over a 2 inch diameter.;The novel aerosol feed system was fully characterized and improved by performing solubility and carbon tests with different metallo-organic solvents and by thermally mapping the heating section. The gas flow profiles in the reactor chamber were modeled with a finite-element software package called Fluent. This enabled us to study different nozzles for improving the uniformity of the velocity near the substrate and the uniformity of the depositions.;Depositions were then performed to test the validity of the computer model and to determine correct molar feed ratios. The uniformity was measured with a scanning electron microscope (SEM) while the film compositions were analyzed with a X-Ray photoelectron spectroscopy system (XPS). Once the correct feed compositions were determined, this ratio was used along with the feed nozzle designed to deposit uniform, superconducting thin films. |
Keywords/Search Tags: | Superconducting thin, System, Feed |
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