Abstract: A true random number generator (TRNG) device having a magnetic tunnel junction (MTJ) structure coupled to a domain wall wire. The MTJ structure is formed of a free layer (FL) and a reference layer (RL) that sandwiches a tunnel barrier layer. The free layer has anisotropy energy sufficiently low to provide stochastic fluctuation in the orientation of the magnetic state of the free layer via thermal energy. The domain wall wire is coupled to the MTJ structure. The domain wall wire has a domain wall. Movement of the domain wall tunes a probability distribution of the fluctuation in the orientation of the magnetic state of the free layer. The domain wall can be moved by application of a suitable current through the wire to tune the probability distribution of 1's and 0's generated by a readout circuit of the TRNG device.

Abstract: A true random number generator (TRNG) device having a magnetic tunnel junction (MTJ) structure coupled to a domain wall wire. The MTJ structure is formed of a free layer (FL) and a reference layer (RL) that sandwiches a tunnel barrier layer. The free layer has anisotropy energy sufficiently low to provide stochastic fluctuation in the orientation of the magnetic state of the free layer via thermal energy. The domain wall wire is coupled to the MTJ structure. The domain wall wire has a domain wall. Movement of the domain wall tunes a probability distribution of the fluctuation in the orientation of the magnetic state of the free layer. The domain wall can be moved by application of a suitable current through the wire to tune the probability distribution of 1's and 0's generated by a readout circuit the TRNG device.

Abstract: A top pinned magnetic tunnel junction (MTJ) stack for use in spin-transfer torque magnetoresistive random access memory (STT MRAM) is provided. The top pinned MTJ stack contains a synthetic anti-ferromagnetic magnetic free layer stack that is formed on an insulating aluminum nitride (AlN) seed layer having hexagonal symmetry. For such a top pinned MTJ stack, the symmetry requirements for the tunnel barrier layer do not conflict anymore with the symmetry requirements for strong anti-ferromagnetic exchange. Further, and compared to using only a metallic seed, the insulating AlN seed layer limits spin pumping from the magnetic free layer into the metallic seed layer and therefore lowers the switching current, while only making a small contribution to the resistance of a STT MRAM.

Abstract: A top pinned magnetic tunnel junction (MTJ) stack for use in spin-transfer torque magnetoresistive random access memory (STT MRAM) is provided. The top pinned MTJ stack contains a synthetic anti-ferromagnetic magnetic free layer stack that is formed on an insulating aluminum nitride (AlN) seed layer having hexagonal symmetry. For such a top pinned MTJ stack, the symmetry requirements for the tunnel barrier layer do not conflict anymore with the symmetry requirements for strong anti-ferromagnetic exchange. Further, and compared to using only a metallic seed, the insulating AlN seed layer limits spin pumping from the magnetic free layer into the metallic seed layer and therefore lowers the switching current, while only making a small contribution to the resistance of a STT MRAM.

Abstract: A double magnetic tunnel junction (MTJ) stack for use in spin-transfer torque magnetoresistive random access memory (STT MRAM) is provided. The double MTJ stack includes a bottom tunnel barrier layer having hexagonal symmetry and composed of AlN, a magnetic free layer stack containing a synthetic anti-ferromagnetic coupling layer, and a top tunnel barrier layer having cubic symmetry. For such a double MTJ stack, the symmetry requirements for the tunnel barrier layers do not conflict anymore with the symmetry requirements for strong anti-ferromagnetic exchange. Thus, such a double MTJ stack can be used to provide performance enhancement such as faster switching times and lower write errors to a STT MRAM.

Abstract: A double magnetic tunnel junction (DMTJ) device includes a fixed reference layer of a first magnetic material having a perpendicular magnetic anisotropy with a magnetic moment that is fixed. The device also includes a free layer of a second magnetic material having a perpendicular magnetic anisotropy with a magnetic moment that is changeable based on a current. A dynamic reference layer of a third magnetic material has an in-plane magnetic anisotropy and a changeable magnetic moment. The free layer is disposed between the fixed reference layer and the dynamic reference layer.

Abstract: A double magnetic tunnel junction (DMTJ) device includes a fixed reference layer of a first magnetic material having a perpendicular magnetic anisotropy with a magnetic moment that is fixed. The device also includes a free layer of a second magnetic material having a perpendicular magnetic anisotropy with a magnetic moment that is changeable based on a current. A dynamic reference layer of a third magnetic material has an in-plane magnetic anisotropy and a changeable magnetic moment. The free layer is disposed between the fixed reference layer and the dynamic reference layer.