Perpendicular magnetic tunnel junction device with precessional spin current layer having a modulated moment density

A magnetic device, comprising:

• a magnetic reference layer in a first plane, the magnetic reference layer having a magnetization vector that is perpendicular to the first plane and having a fixed magnetization direction;
• a non-magnetic tunnel barrier layer in a second plane and disposed over the magnetic reference layer;
• a free magnetic layer disposed in a third plane over the non-magnetic tunnel barrier layer, the free magnetic layer having a magnetization vector that is perpendicular to the third plane and having a magnetization direction that can switch between a first magnetization direction to a second magnetization direction, the magnetic reference layer, the non-magnetic tunnel barrier layer and the free magnetic layer forming a magnetic tunnel junction;
• and
• a precessional spin current magnetic layer having a non-uniform moment density, the precessional spin current magnetic layer disposed in a fourth plane that is physically separated from the free magnetic layer and coupled to the free magnetic layer by a filter coupling layer that may induce ferromagnetic or antiferromagnetic coupling between the free magnetic layer and the filter layer.

A method for manufacturing a magnetic device comprising the steps of:

• providing a magnetic tunnel junction including a magnetic reference layer, a non-magnetic tunnel barrier layer, and a free magnetic layer;
• depositing a filter coupling layer over the free magnetic layer;
• depositing a first material to form a precessional spin current magnetic layer over the filter coupling layer;
• forming a partial pillar that includes the precessional spin current magnetic layer;
• depositing a second material to further form the precessional spin current magnetic layer, the second material having a moment density that is less than a moment density of the first material;
• depositing a hard mask layer over the precessional spin current magnetic layer;
• forming a pillar that includes the precessional spin current magnetic layer, the filter coupling layer, the free magnetic layer, the non-magnetic tunnel barrier layer, and the magnetic reference layer such that the precessional spin current magnetic layer has a diameter that is different from a diameter of the free magnetic layer;
• and
• depositing an electrical contact layer over the precessional spin current layer.