Liquid-Nitrogen-Cooled Dry Etching of YBaCuO Thin Films

Abstract
A new dry etching method has been developed for patterning YBaCuO thin films with less damage, wherein samples are cooled by liquid nitrogen. It is found that the critical current density J c of films etched by this cooling method is significantly improved, more than one order of magnitude higher than that for the films etched at 5°C. Furthermore, it is found that this technique causes less damage to the surface of the YBaCuO films, compared to the etching at 5°C. This result suggests that the dry etching process with liquid nitrogen cooling is a promising method for the fabrication of high-T c superconducting electronic devices of small dimensions.