Magnetoresistance element and semiconductor memory device

A magnetoresistance element comprising:

• a first free magnetization layer;
• a first tunnel insulating layer formed on the first free magnetization layer;
• a first fixed magnetization layer formed on the first tunnel insulating layer;
• an antiferromagnetic layer formed on the first fixed magnetization layer;
• a second fixed magnetization layer formed on the antiferromagnetic layer;
• a second tunnel insulating layer formed on the second fixed magnetization layer;
• and
• a second free magnetization layer formed on the second tunnel insulating layer.

A semiconductor memory device comprising:

• a magnetoresistance element;
• and
• a MOS transistor having either of source/drain regions electrically connected to the magnetoresistance element, wherein
• the magnetoresistance element comprises:
• a first magnetoresistance subelement including a first free magnetization layer, a first tunnel insulating layer and a first fixed magnetization layer, the first tunnel insulating layer interposed between the first free magnetization layer and the first fixed magnetization layer, a magnetization direction of the first free magnetization layer changing according to an electric current flowing in a thickness direction of the first magnetoresistance subelement, and a resistance of the first magnetoresistance subelement changing between a low resistance state and a high resistance state according to the magnetization direction of the first free magnetization layer;
• and
• a second magnetoresistance subelement including a second free magnetization layer, a second tunnel insulating layer and a second fixed magnetization layer, the second tunnel insulating layer interposed between the second free magnetization layer and the second fixed magnetization layer, a magnetization direction of the second free magnetization layer changing according to an electric current flowing in a thickness direction of the second magnetoresistance subelement, and a resistance of the second magnetoresistance subelement changing between a low resistance state and a high resistance state according to the magnetization direction of the second free magnetization layer, and wherein
• the first and second magnetoresistance subelements are stacked each other, and
• an order of the first free magnetization layer and the first fixed magnetization layer is opposite to an order of the second free magnetization layer and the second fixed magnetization layer in a thickness direction of the magnetoresistance element.