Magnetic tunnel junction based anti-fuses with cascoded transistors

A method for protecting an unselected magnetic tunnel junction in an array of magnetic tunnel junctions from being accidentally blown by antifuse programming voltage applied to a selected magnetic tunnel junction wired in parallel therewith, the method comprising:

• connecting said selected magnetic tunnel junction serially with a first field effect transistor and a second field effect transistor, the first field effect transistor having its gate connected to an unswitchable positive supply voltage while the gate of the second field effect transistor is switchably connected to a programming voltage of 1.5 to 2 volts;
• connecting a first electrode of the selected magnetic tunnel junction to a bias line and connecting a second electrode of the selected magnetic tunnel junction to an electrode of the first field effect transistor;
• switching the second field effect transistor of the selected magnetic tunnel junction to direct the programming voltage to program the selected magnetic tunnel junction while the unselected magnetic tunnel junction is unswitched, and the unswitched magnetic tunnel junction and the second field effect transistor do not experience a voltage drop across the gates thereof sufficient to degrade an oxide of a transistor associated with the unswitched magnetic tunnel junction;
• and
• wherein the selected magnetic tunnel junction has a resistance of 10 kΩ to 20 kΩ prior to application of the programming voltage and wherein the selected magnetic tunnel junction, upon application of the programming voltage, is shorted across a tunnel dielectric layer so as to have a resistance of 10 Ω to 1 kΩ.