A spin dependent tunneling ("SDT") junction of a memory cell for a Magnetic Random
Access Memory ("MRAM") device includes a pinned ferromagnetic layer, followed by
an insulating tunnel barrier and a sense ferromagnetic layer. During fabrication
of the MRAM device, after formation of the pinned layer but before formation of
the insulating tunnel barrier, an exposed surface of the pinned layer is flattened.
The exposed surface of the pinned layer may be flattened by an ion etching process.
