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Title: The diagnosis of electronegative magnetron plasmas
Author: Scribbins, Steven
ISNI:       0000 0004 5351 3264
Awarding Body: University of Liverpool
Current Institution: University of Liverpool
Date of Award: 2014
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The magnetron sputter tool has been employed for many years to manufacture engineering-quality thin films and coatings. While many aspects of magnetron plasmas have been extensively studied, much is still unknown. This project aims to develop a more complete picture of the magnetron sputtering plasma by performing laser-assisted electron photodetachment diagnostics to measure the density of negative ion species in these plasmas. Concentrations of negative oxygen ions were measured in oxygen/argon mixtures, and negative hydrogen ions in hydrogen discharges. Concentrations were plotted spatially across the midplane of the discharge to determine the 2-dimensional distribution of negative ions. The evolution of concentration with time is also measured. Negative ions were found to follow a spatial distribution pattern which appears to be independent of the discharge gas type, and are at maximum concentration in the diffuse region of the discharge above the magnetic field trap and off the central axis. Regions of moderately high plasma electronegativity were observed, with concentrations of negative ions exceeding the local electron density at some locations. Hydrogen discharges were shown to follow a similar pattern, however the overall proportion of negative ions within the hydrogen discharge was seen to be at lest a factor of ten lower than in the oxygen case.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available