A reproducible design and manufacturing process for SQUID magnetometers
Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2005.
A process was developed to design and manufacture a dc SQUID magnetometer. Superconductor theory is given as a foundation to explain the Josephson junction. This knowledge is applied to explain the ideal and practical dc SQUID. The design of the dc SQUID is done with inductance calculation formulas. Each step of the manufacturing process is discussed in detail. Many improvements have been made to the process to make each step reproducible. The steps in the manufacturing process that were done in-house are: manufacturing an YBa2Cu3O7−d pellet, depositing the thin film with the pulsed laser deposition process, creating a mask with the UV lithography process, wet etching the circuit and depositing silver contact pads with thermal evaporation. The device is packaged on a printed circuit board device holder and shielded with a mu-metal shield. A test setup is developed to test the final device. Each step in the manufacturing process was successful. The final device did not work, due to oxidisation of the YBa2Cu3O7−d thin film.