Magnetic random access memory with selective toggle memory cells

A method of selectively writing to a toggle MTJ cell formed between a bit line and word line in a crossover region in a MRAM array wherein the word line and bit line are aligned at the same 45° to 60° angle relative to an easy axis of a SAF free layer in said toggle MTJ cell, said SAF free layer has a plurality of “n” magnetic sub-layers including an inner sub-layer and an outer sub-layer with equal magnetic moments wherein “n” is an even integer and the inner sub-layer or the outer sub-layer has a greater anisotropy than the other sub-layers, and an anti-parallel coupling layer between adjacent magnetic sub-layers, comprising:

• (a) applying a word line current pulse and a matching bit line current pulse during a first time interval wherein the sum of the magnetic fields generated by said pulses is parallel to the easy axis and is larger than the spin-flop field of the SAF free layer with sufficient margin to write a memory state;
• and
• (b) reducing the word line current pulse and the bit line current pulse in a matching manner to zero with a falling edge design during a second time interval.

A magnetic random access memory (MRAM) structure having a toggle MTJ cell wherein a synthetic anti-ferromagnetic (SAF) free layer formed adjacent to a tunnel barrier layer is comprised of a stack that has a first magnetic sub-layer disposed on the tunnel barrier layer, a coupling layer on the first magnetic sub-layer, and a second magnetic sub-layer on the coupling layer, said magnetic sub-layers have the same magnetic moment but the first magnetic sub-layer has a greater anisotropy than the second magnetic sub-layer.