Vortex magnetic random access memory

An MRAM structure formed on a substrate, comprising:

• (a) an array of first conductive lines formed on a first horizontal plane;
• (b) an array of parallel second conductive lines oriented in a direction orthogonal to the first conductive lines and in a second horizontal plane that is parallel to and formed above the first horizontal plane;
• and
• (c) an array of MTJs disposed between said first horizontal plane and said second horizontal plane wherein an MTJ is formed at each location where a second conductive line crosses over a first conductive line, said MTJs are comprised of:
• (1) a free layer having a dopant for lowering the exchange coupling constant therein, said free layer has a vortex magnetization with a rotational direction;
• (2) a reference layer having a dopant for lowering the exchange coupling constant therein, said reference layer has a vortex magnetization with a rotational direction that is pinned by an adjacent anti-ferromagnetic (AFM) layer;
• and
• (3) a tunnel barrier layer formed between said free layer and reference layer.

A method of forming a vortex magnetization state in a magnetic layer in an MTJ, comprising:

• (a) providing a substrate on which a first conductive line is formed along a first axis;
• (b) forming an MTJ on said first conductive line, said MTJ has an elliptically shaped sidewall, top and bottom surfaces, a length and a width, and is comprised of a reference magnetic layer and a free magnetic layer in which a remnant magnetization is aligned in a first direction;
• (c) forming a second conductive line that contacts the top surface of said MTJ and is formed along a second axis orthogonal to said first axis;
• (d) generating currents in said first and second conductive lines that produce a reverse magnetic field in a second direction opposite to the first direction, said reverse magnetic field induces a vortex magnetization state in said free magnetic layer;
• and
• (e) removing said reverse magnetic field.

A method of switching a vortex magnetization state from a first rotational direction to a second rotational direction in a free magnetic layer of an MTJ, comprising:

• (a) providing a substrate on which a first conductive line is formed, a second conductive line is formed above and orthogonal to said first conductive line, and an MTJ is formed therebetween, said MTJ has an elliptically shaped sidewall, top and bottom surfaces, a length and a width, and is comprised of a free magnetic layer that has a vortex magnetization formed in a first rotational direction;
• (b) applying a first magnetic field with sufficient magnitude in a first direction along a first axis to break the vortex magnetization and generate a remnant magnetization within the free layer in said first direction;
• (c) removing said first magnetic field;
• (d) applying a second magnetic field in a second direction opposite to said first direction, said second magnetic field has a magnitude that induces a vortex magnetization in a second rotational direction opposite to said first rotational direction;
• and
• (e) removing said second magnetic field.