A magnetic data track used in a magnetic shift register memory system may
be fabricated by forming a multilayered stack of alternating dielectric
and/or silicon layers. Vias of approximately 10 microns tall with a
cross-section on the order of 100 nm.times.100 nm are etched in this
multilayered stack of alternating layers. Vias may be etched form smooth
or notched walls. Vias are filled by electroplating layers of alternating
types of ferromagnetic or ferrimagnetic metals. The alternating
ferromagnetic or ferrimagnetic layers are comprised of magnetic materials
with different magnetization or magnetic exchange or magnetic
anisotropies. These different magnetic characteristics allow the pinning
of magnetic domain walls at the boundaries between these layers.
Alternatively, vias are filled with a homogeneous ferromagnetic material.
Magnetic domain walls are formed by the discontinuity in the
ferromagnetic or ferromagnetic material that occurs at the notches or at
the protuberances along the via walls.