Magnetoresistive memory device

A magnetoresistive memory device comprising:

• first to n-th layer stacks, where n is a natural number equal to or greater than 2, wherein
• a X-th layer stack is positioned above a (X−1)-th layer stack for all cases of X, where X is every natural number from 2 to n,
• each of the first to n-th layer stacks includes:
• a first ferromagnetic layer having a magnetization directed in a first direction;
• a non-magnetic first conductive layer above the first ferromagnetic layer,
• a second ferromagnetic layer provided above the first conductive layer and having a magnetization directed in a second direction different from the first direction,
• a first insulating layer on an upper surface of the second ferromagnetic layer, and
• a third ferromagnetic layer above the first insulating layer, and
• for each of all cases of X being 2 to n, the second ferromagnetic layer of the X-th layer stack is thicker than the second ferromagnetic layer of the (X−1)-th layer stack.

A magnetoresistive memory device comprising:

• a first layer stack and a second layer stack, wherein
• each of the first layer stack and the second layer stack includes:
• a first ferromagnetic layer having a magnetization directed in a first direction;
• a non-magnetic first conductive layer above the first ferromagnetic layer,
• a second ferromagnetic layer provided above the first conductive layer and having a magnetization directed in a second direction different from the first direction,
• a first insulating layer on an upper surface of the second ferromagnetic layer, and
• a third ferromagnetic layer above the first insulating layer, and
• the first conductive layer of the second layer stack has a thickness different from the first conductive layer of the first layer stack.

A magnetoresistive memory device comprising:

• first to n-th layer stacks, where n is a natural number equal to or greater than 2, wherein
• a X-th layer stack is positioned above a (X−1)-th layer stack for all cases of X, where X is every natural number from 2 to n,
• each of the first to n-th layer stacks includes:
• a first ferromagnetic layer having a magnetization directed in a first direction;
• a non-magnetic first conductive layer above the first ferromagnetic layer,
• a second ferromagnetic layer provided above the first conductive layer and having a magnetization directed in a second direction different from the first direction,
• a first insulating layer on an upper surface of the second ferromagnetic layer, and
• a third ferromagnetic layer above the first insulating layer, and
• for each of all cases of X being 2 to n, the first conductive layer of the X-th layer stack is thicker than the first conductive layer of the (X−1)-th layer stack, or
• for each of all cases of X being 2 to n, the first conductive layer of the X-th layer stack is thinner than the first conductive layer of the (X−1)-th layer stack.