Patent ID: 7957179

Claim:
A device, comprising: a substrate; a magnetic cell formed over the substrate and comprising: a first ferromagnetic layer exhibiting a first magnetization that is switchable between a first direction and a second substantially opposite direction under a spin-transfer torque effect caused by an electric current; a second ferromagnetic layer having a fixed magnetization along one of the first and second directions; and a non-magnetic spacer layer formed between the first and second ferromagnetic layers to allow for passage of the electric current between the first and second ferromagnetic layers; a magnetic shielding layer formed over the substrate and comprising a magnetic material that exhibits a negative susceptibility, the magnetic shielding layer patterned to comprise an opening that penetrates through the magnetic shielding layer, wherein the magnetic cell is located inside the opening of the magnetic shielding layer to be surrounded by the magnetic material of the magnetic shielding layer; and a circuit electrically coupled to the magnetic cell and operable to supply the electric current flowing through the magnetic cell.