An asymmetric cell and bit design for an MRAM device. The design is
asymmetrical with respect to the easy-axis of the cell and has a centroid
displaced from bit center along the hard-axis of the cell. This asymmetry
is large enough so that manufacturing process variations do not
substantially change the switching fields of the bits. In addition, the
asymmetry causes the ends of the bits to align in opposite directions in
small half-select fields and parallel to each other at large half-select
fields, which increases the difference in the switching fields between
selected and unselected bits. The combined effect of these two
characteristics results in increased bit yield (relative to similarly
sized symmetric bits) due to a smaller overlap between selected and
unselected bit switching distributions.