Patent ID: 7576956
Filing Date: 2009-08-18
Classification: G01R,G11C,H01L

Abstract:
1. A device, comprising: a substrate; first and second magnetic layers formed over the substrate, wherein the first magnetic layer is located between the substrate and the second magnetic layer; an insulator barrier layer formed between the first and second magnetic layers to effectuate tunneling of electrons between the first and second magnetic layers under a bias voltage applied between the first and second magnetic layers and across the insulator barrier layer; a diffusion stop layer formed between the first magnetic layer and the insulator barrier layer to permit the tunneling and prevent diffusion of particles from the insulator barrier layer into the first magnetic layer, wherein the first magnetic layer is a magnetically pinned ferromagnetic layer whose magnetization is fixed in a first direction, and the second magnetic layer is a free ferromagnetic layer whose magnetization is controllable to be either substantially parallel to or substantially opposite to the fixed magnetization of the first ferromagnetic layer; a second insulator barrier layer formed above the second ferromagnetic layer; a second diffusion stop layer formed between the second ferromagnetic layer and the second insulator barrier layer to prevent diffusion of particles from the second insulator barrier layer into the second ferromagnetic layer; a third ferromagnetic layer formed above the second insulator barrier layer and magnetically pinned, wherein the second insulator barrier layer and the second diffusion stop layer are structured to effectuate tunneling of electrons between the second and the third ferromagnetic layers under a second bias voltage applied between the second and the third ferromagnetic layers; and a third diffusion stop layer formed between the second ferromagnetic layer and the first insulator barrier layer to permit the tunneling and to prevent diffusion of particles from the first insulator baffler layer into the second ferromagnetic layer.