Bromine Etching of Patterned YBa₂Cu₃O_6+x Nanoscale Thin Films for High-Temperature Superconducting Devices

Abstract

Cuprate high-temperature superconducting (HTS) thin films like YBa 2 Cu 3 O 6+x (YBCO) are subject to reduction reactions with CO 2 and H 2 O. This poses a challenge for processing and storing nanoscale devices made from these films. A 1% bromine−ethanol etchant solution was investigated as a facile processing method for thin 50 nm films of patterned YBCO. Raman scattering, EDS, AFM, and HIM imaging show changes in the surface morphology and composition. RT measurements show electrical changes to a depth of ∼3 nm after bromination and a slight reduction in T c (86.5 to 86.4 K). We conclude that bromination of YBCO has minimal electrical consequences.