Surface Properties of a YBa2Cu3O7-δ Thin Film After Photo-Lithographic Treatment

The effect of photolithographic treatments on the surface of a YBa2Cu3O7-δ thin film has been investigated by measuring the electrical contact resistance and performing X-ray photoemission spectroscopy (XPS) experiment. Water plays an important role in increasing the electrical contact resistance of the YBa2Cu3O7-δ thin film, as compared with the developer and photoresist (PR); water removes oxygen from the surface and increases the contact resistance. The chemical interaction with the PR or developer is not a key element in increasing the contact resistance. XPS spectra show that the oxygen concentration of the surface of a YBa2Cu3O7-δ thin film is reduced after the photolithographic process.