Magnetic random access memory, magnetic random access memory manufacturing method, and magnetic random access memory write method

A magnetic random access memory comprising:

• a first write wiring which runs in a first direction;
• a second write wiring which runs in a second direction different from the first direction and has a first crossing angle and second crossing angle formed by crossing the first write wiring, the first crossing angle and second crossing angle being located on both sides of the first write wiring serving as a boundary;
• a first magnetoresistive element which is arranged at an intersection of the first write wiring and the second write wiring between the first write wiring and the second write wiring, has a first axis of easy magnetization directed to a side of the first crossing angle, and has a first fixed layer, a first recording layer, and a first tunnel barrier layer sandwiched between the first fixed layer and the first recording layer, the first recording layer including a first ferromagnetic layer located on a side of the first fixed layer, a second ferromagnetic layer, and a first nonmagnetic layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer;
• and
• a second magnetoresistive element which is arranged at the intersection of the first write wiring and the second write wiring between the first write wiring and the second write wiring and electrically connected to the first magnetoresistive element, has a second axis of easy magnetization directed to a side of the second crossing angle, and has a second fixed layer, a second recording layer, and a second tunnel barrier layer sandwiched between the second fixed layer and the second recording layer.

A write method of a magnetic random access memory which includes

• a first write wiring which runs in a first direction,
• a second write wiring which runs in a second direction different from the first direction and has a first crossing angle and second crossing angle formed by crossing the first write wiring, the first crossing angle and second crossing angle being located on both sides of the first write wiring serving as a boundary,
• a first magnetoresistive element which is arranged at an intersection of the first write wiring and the second write wiring between the first write wiring and the second write wiring, has a first axis of easy magnetization directed to a side of the first crossing angle, and has a first fixed layer, a first recording layer, and a first tunnel barrier layer sandwiched between the first fixed layer and the first recording layer, the first recording layer including a first ferromagnetic layer located on a side of the first fixed layer, a second ferromagnetic layer, and a first nonmagnetic layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, and
• a second magnetoresistive element which is arranged at the intersection of the first write wiring and the second write wiring between the first write wiring and the second write wiring and electrically connected to the first magnetoresistive element, has a second axis of easy magnetization directed to a side of the second crossing angle, and has a second fixed layer, a second recording layer, and a second tunnel barrier layer sandwiched between the second fixed layer and the second recording layer, the second recording layer including a third ferromagnetic layer located on a side of the second fixed layer, a fourth ferromagnetic layer, and a second nonmagnetic layer sandwiched between the third ferromagnetic layer and the fourth ferromagnetic layer,
• the write method writing binary information in the first magnetoresistive element and second magnetoresistive element by supplying a first write current to the first write wiring and a second write current to the second write wiring, comprising:
• starting supplying one current of one of the first write current and second write current earlier than the other current of the other of the first write current and second write current;
• supplying the other current in addition to the one current;
• reducing a current value of the one current to not more than a write threshold value earlier than the other current;
• and
• reducing a current value of the other current to not more than the write threshold value,
• wherein an order of starting or ending supply of the first write current and second write current and directions in which the first write current and second write current are supplied are changed to selectively cause one of the first magnetoresistive element and second magnetoresistive element to execute a toggle operation.

A write method of a magnetic random access memory which includes

• a first write wiring which runs in a first direction,
• a second write wiring which runs in a second direction different from the first direction and has a first crossing angle and second crossing angle formed by crossing the first write wiring, the first crossing angle and second crossing angle being located on both sides of the first write wiring serving as a boundary,
• a first magnetoresistive element which is arranged at an intersection of the first write wiring and the second write wiring between the first write wiring and the second write wiring, has a first axis of easy magnetization directed to a side of the first crossing angle, and has a first fixed layer, a first recording layer, and a first tunnel barrier layer sandwiched between the first fixed layer and the first recording layer, the first recording layer including a first ferromagnetic layer located on a side of the first fixed layer, a second ferromagnetic layer, and a first nonmagnetic layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, and
• a second magnetoresistive element which is arranged at the intersection of the first write wiring and the second write wiring between the first write wiring and the second write wiring and electrically connected to the first magnetoresistive element, has a second axis of easy magnetization directed to a side of the second crossing angle, and has a second fixed layer, a second recording layer, and a second tunnel barrier layer sandwiched between the second fixed layer and the second recording layer,
• the write method writing binary information in the first magnetoresistive element and second magnetoresistive element by supplying a first write current to the first write wiring and a second write current to the second write wiring, comprising:
• starting supplying one current of one of the first write current and second write current earlier than the other current of the other of the first write current and second write current;
• supplying the other current in addition to the one current;
• reducing a current value of the one current to not more than a write threshold value earlier than the other current;
• and
• reducing a current value of the other current to not more than the write threshold value,
• wherein an order of starting or ending supply of the first write current and second write current and directions in which the first write current and second write current are supplied are changed to selectively independently execute a first operation and second operation,
• the first operation is causing or not causing the first magnetoresistive element to execute a toggle operation, and
• the second operation is reversing magnetization in the second recording layer of the second magnetoresistive element.

A magnetic random access memory manufacturing method comprising:

• forming a first write wiring;
• forming a first electrode above the first write wiring;
• forming a first material layer on the first electrode;
• processing the first material layer to form a first magnetoresistive element having a first axis of easy magnetization directed in a first direction;
• forming a interlayer around the first magnetoresistive element;
• forming a second electrode on the first magnetoresistive element;
• forming a second material layer on the second electrode;
• processing the second material layer to form a second magnetoresistive element having a second axis of easy magnetization directed in a second direction different from the first direction;
• and
• forming a second write wiring above the second magnetoresistive element.

A magnetic random access memory manufacturing method comprising:

• forming a first write wiring;
• forming a first electrode above the first write wiring;
• forming a first material layer, a contact layer, and a second material layer sequentially on the first electrode;
• processing the first material layer, the contact layer, and the second material layer at once to form a first magnetoresistive element, a contact, and a second magnetoresistive element;
• and
• forming a second write wiring above the second magnetoresistive element.

A magnetic random access memory manufacturing method comprising:

• forming a first write wiring and a first magnetoresistive element above a first substrate;
• forming a contact connected to the first magnetoresistive element;
• forming a second write wiring and a second magnetoresistive element above a second substrate different from the first substrate;
• and
• bonding the first substrate and second substrate to electrically connect the first magnetoresistive element and second magnetoresistive element through the contact.