Chemical etching of Y-Cu-Ba-O thin films

Thin films of Y-Ba-Cu-O have been deposited by rf sputtering using a stoichiometric target on alumina, zirconia, and Y2O3 coated silicon substrates. After a brief heat treatment in oxygen, a resistive transition was observed with an onset temperature from 89 to 94.6 K. Etching experiments of the as-deposited films have been made to determine the etching rates of the compound. It was found that reproducible results can be readily obtained using the following solutions: H3PO4/H2O, HNO3/H2O, and HCl/H2O. Using a positive photoresist technology, 3 μm lines have been successfully produced by etching in these solutions. The present patterning process was found to have no deleterious effect on the superconducting characteristics of the Y-Ba-Cu-O films.