Properties of lift-off structured high T/sub c/ microbridges

Abstract
Microbridges and dc-SQUIDS were fabricated in lift-off technique from rf sputtered YBaCuO films on MgO single crystal substrates. Microwave measurements at 9GHz on microbridges and the magnetic field depen- dence of their critical current reveal wide bridge be- havior up to temperatures near the maximum operating temperature of the bridge. Mostly a linear dependence of the critical current on the temperature is found, which is connected to high intrinsic l/f-noise if the bridge is constant current biased slightly above the critical current. In some bridges and dc-SQUIDS regimes with a temperature dependence proportional to (1- TIT )I.' are found. In this case the l/f noise level is muck smaller and SQUID modulation can be follswed to about 65K.