Reliability of field programmable magnetic logic gate arrays

In concepts for logic circuits using hysteretic magnetoresistive effects, one gains advantages of magnetic thin-film elements, e.g., nonvolatility, radiation hardness and nondestructive readout. The requirements concerning reproducibility of resistance and magnetoresistance, however, are much more stringent than for memory applications. Using experimental data of magnetic logic circuits, we show that the variances of resistance and magnetoresistance, and the amplitude of the magnetoresistance, determine the yield of working logic gates. The current magnetoresistance of 75% for CoFeB/Al2O3 junctions is close to the minimum required value. More than 250% obtained with MgO barriers, however, will allow a fault tolerant production. (c) 2006 American Institute of Physics.