To Develop a Process for the Fabrication of Thin Film Copper RF Coils on Glass by Sputter Deposition.
Date of Award
Masters of Science (Research)
Applied Physics & Instrumentation
Mr. Eamonn Butler
A fabrication process was developed to produce thin film probe coils for use in high resolution NMR spectroscopy. Sputter deposited thin film copper coils in the micron range were investigated as a potential replacement for the traditional 1mm diameter copper wire coils currently used.
In NMR spectroscopy higher resolution may be achieved by employing higher field strength magnets which increases the intensity of the inherently weak NMR signal. A reduction in the mass of the copper probe coil through thin film deposition was anticipated to reduce the disturbance to the homogeneity of the magnetic field at higher field strengths. This would have the effect of improving the resolution of the detected NMR signal.
The planar magnetron sputtering system used in this work was new to the laboratory and required comprehensive characterisation and design modifications at the commencement of this work. Adhesion experiments were performed to assess the adhesion of sputtered copper to the glass substrates. 20pm planar copper coils on 50mm X 50mm glass were deposited. Wobble tests performed showed little disturbance of the magnetic field when tested at 500MHz and Q tests yielded a Q factor of 140. A number of well-defined coils of thickness 10-20pm were sputtered onto 6mm diameter cylindrical NMR glass tubes coated with Si02 as an adhesion promoter. Q tests perfoiTned on these saddle coils gave disappointing results. The inadequate adhesion of the copper to the glass substrate, the geometry of the coils and the thickness of copper may all have contributed to the low Q factor values (25, 46).
The suitability of the magnetron sputtering deposition system for the formation of copper coils has been established. Furthermore it has been shown that a reduction in the mass of copper does indeed dramatically reduce the inhomogeneity caused by the presence of the copper.
Baldwin, Eleanor Maria, "To Develop a Process for the Fabrication of Thin Film Copper RF Coils on Glass by Sputter Deposition." (2005). Theses [online].
Available at: https://sword.cit.ie/allthe/153
Presented by Eleanor Maria Baldwin, BSc.(Applied Physics).
Submitted to the Higher Education and Training Awards Council, September, 2005.