An MTJ pattern layout for a memory device is disclosed that includes two
CMP assist features outside active MTJ device blocks. A first plurality
of dummy MTJ devices is located in two dummy bands formed around an
active MTJ device block. The inner dummy band is separated from the outer
dummy band by the MTJ ILD layer and has a MTJ device density essentially
the same as the MTJ device block. The outer dummy band has a MTJ device
density at least 10% greater than the inner dummy band. The inner dummy
band serves to minimize CMP edge effect in the MTJ device block while the
outer dummy band improves planarization. A second plurality of dummy MTJ
devices is employed in contact pads outside the outer dummy band and is
formed between a WL ILD layer and a BIT ILD layer thereby minimizing
delamination of the MTJ ILD layer.