Disturb mechanisms in coupled-film bulk memory elements

Performance of magnetic film memory arrays is limited by various disturb mechanisms that can completely erode written information if the array design inadequately provides for process variations, strip line attenuation, power supply variations, etc. This paper reports on several particularly relevant disturb mechanisms in coupled-film closed-easy-axis (CFCEA) arrays [1] intended for large capacity NDRO multiple-write bulk memory application. Two new design guidelines for densities bit/in²are presented: 1) minimization of creep sensitivity to alternating interrogate and bit disturbs and 2) prevention of the formation of uncoupled interbit domains. Both can be achieved by mismatching the effective coercive fields of the coupled films in the same ratio as the applied easy-axis fields.