Magnetoresistive detector for flat domain propagation shift register

A magnetoresistance read out station for a flat domain shift register has been optimized. The structure consists of a 4μm wide folded stripe of a 2500 Å thick NiFe film electro deposited on a thin electroless copper, above a polyimid insulating layer. Although the precise magnetization dis tribution in the magnetoresistor is unknown, the efficiency of detection can be analysed when considering the magnetic field level at each point of the magnetoresistive stripe which can be computed, and the corresponding slope of the experimental characteristic curve . When the maximum slope occurs at the average total applied field of 20 Oe, a usable signal of 1 mV is obtained for an excitation current of 4.5 mA. In these conditions a signal to noise ratio of 28 is obtained in a sense amplifier accepting for input a bridge linking eight sense lines of 32 stations each The corresponding error rate due to the detection is negligible before the expected error rate of 10^-12for the shifting mechanism. The fabrication process is described in terms of optimizing for the important parameters.