Patent ID: 7598597
Filing Date: 2009-10-06
Classification: G11C,H01L

Abstract:
1. An effective magnetic shielding structure for a segmented MRAM array, having a top surface, comprising: a number of bit slice segments each of which contains a number of bit lines; a number of word lines, each such word line being independently addressable whereby it can interact with one and only one of said bit slice segments at any given time; a first dielectric layer on said array top surface; on said first dielectric layer, a plurality of soft magnetic segmented shields, each of which fully covers and overlaps one of said bit slice segments, said segmented shields being spaced a distance apart from one another; at each end of each of said segmented shields, a pad of magnetic material that applies a permanent longitudinal magnetic bias to its associated segmented shield, each such pad overlapping its associated segmented shield without overlapping any part of its associated bit slice segment, whereby each segmented shield is a single magnetic domain; a second dielectric layer that fully covers said MRAM array and said segmented shields and pads; and a master magnetic shield layer on said second dielectric layer.