Preparation of YBaCuO Thin Film dc SQUID

This paper discusses the preparation of thin oxide film dc SQUIDs (Superconducting Quantum Interference Devices). A c-axis oriented, 600 nm-thick polycrystalline as-grown superconducting Y-Ba-Cu-O thin film, which was deposited on a (100) SrTiO3 single crystal, was used. An Ar ion milling technique has successfully been applied for patterning the 5∼20 µm wide microbridge without causing damage to the film. The modulation of the critical current has been clearly observed from 4.2 K to slightly higher than 40 K.