Fabrication of microstructured magnetic tunneling valve junction

A microstructured magnetic tunneling valve junction was fabricated with a photolithographic technique. The base and counter electrodes of 78Ni-Fe and Co were deposited by conventional rf sputtering. Rf sputter oxidation was applied to form the tunneling barrier on the intermediate Al surface; typical sputtering parameters used in the experiments were rf power of 0.4 w/cm/sup 2/ and oxygen pressure of 50 mTorr. The magnetoresistance ratio of 0.2% (resistance R=4.1 /spl Omega/, /spl Delta/R=8 m/spl Omega/) was observed at room temperature in the microstructured 40/spl times/40 /spl mu/m/sup 2/ junction.