Magnetic random access memory

A magneto resistive element comprising:

• a first magnetic layer whose magnetized state changes in accordance with data;
• a nonmagnetic layer disposed on the first magnetic layer;
• and
• a second magnetic layer which is disposed on the nonmagnetic layer and whose magnetized state is fixed,
• wherein a ratio (L1/L2) of a maximum length L1 of a first direction to a maximum length L2 of a second direction crossing the first direction at right angles in the first magnetic layer is smaller than a ratio (L3/L4) of a maximum length L3 of the first direction to a maximum length L4 of the second direction in the second magnetic layer, and L2>L4.

A magnetic random access memory comprising:

• a magneto resistive element comprising a first magnetic layer whose magnetized state changes in accordance with data, a second magnetic layer whose magnetized state is fixed, and a nonmagnetic layer disposed between the first and second magnetic layers;
• a conductive line disposed above the magneto resistive element;
• and
• a contact pillar which connects the magneto resistive element to the conductive line,
• wherein at least the first magnetic layer of the magneto resistive element has a cross shape in which a maximum length of a first direction is L1 and a maximum length of a second direction crossing the first direction at right angles is L2, and the contact pillar has a tetragonal shape in which the maximum length of the first direction is D1 (≦L1) and the maximum length of the second direction is D2 (<L2).

A magnetic random access memory comprising:

• a magneto resistive element comprising a first magnetic layer whose magnetized state changes in accordance with data, a second magnetic layer whose magnetized state is fixed, and a nonmagnetic layer disposed between the first and second magnetic layers;
• a conductive line disposed above the magneto resistive element;
• and
• a contact pillar which connects the magneto resistive element to the conductive line,
• wherein a ratio (L1/L2) of a maximum length L1 of a first direction to a maximum length L2 of a second direction crossing the first direction at right angles in at least the first magnetic layer of the magneto resistive element is smaller than a ratio (D1/D2) of a maximum length D1 of the first direction to a maximum length D2 of the second direction in the contact pillar, and L2>D2.

A magnetic resistive element comprising:

• a first magnetic layer;
• a nonmagnetic layer disposed on the first magnetic layer;
• and
• a second magnetic layer which is disposed on the nonmagnetic layer and whose magnetized state changes in accordance with data,
• wherein the second magnetic layer has a cross shape in which a maximum length of a first direction is L1 and a maximum length of a second direction crossing the first direction at right angles is L2, and the first magnetic layer has a tetragonal shape in which the maximum length of the first direction is L1.