LOWER-SUBMICRON PATTERNING PROCESS FOR BISRCACUO HIGH-TC SUPERCONDUCTING THIN-FILMS

Ion bombardment enhanced etching (IBEE) has been successfully applied to BiSrCaCuO high-T(c) superconducting thin films using nonaqueous Br2 solution. It was found that the etch rate of the damaged region which was formed by the ion irradiation with a 200 keV Si++ focused ion beam was enhanced with the Br2 treatment. The critical dose of the IBEE process was about 1 X 10(14) ions/cm2, which is roughly the same as the dose which destroys the superconductivity of the film. Bridge structures with a width of 0.2 mum were successfully fabricated with little degradation in T(c) and J(c). The 0.2-mum bridge had a J(c) value of more than 10(5) A/cm2 below 20 K.