Patent ID: 7522389

Claim:
A magnetoresistance effect element comprising: a first ferromagnetic layer; a second ferromagnetic layer; and at least one nano-contact portion formed between said first and second ferromagnetic layers on a same plane, wherein said nano-contact portion has a maximum dimension of not more than Fermi length of a material constituting the nano-contact portion and the nano-contact portion is made of a same material as that of the first and second ferromagnetic layers, and further wherein said first ferromagnetic layer, said at least one nano-contact portion, and said second ferromagnetic layer are formed as a single layer using a deposition process, further comprising an in-stack bias layer disposed on the first ferromagnetic layer so as to control the magnetization direction of the first ferromagnetic layer, and wherein the first ferromagnetic layer is formed at a predetermined contracting angle of θ 1 towards the nano-contact portion and the second ferromagnetic layer is also formed at a predetermined contracting angle of θ 2 towards the nano-contact portion, said contracting angles each being in a range of 10 to 90° selected so as to make maximum or substantially maximum a magnetic resistance change rate of an obtained magnetoresistance effect element, and wherein said second ferromagnetic layer forms a pinned layer having magnetization which is fixed in a direction apart from the nano-contact portion, and wherein said in-stack bias layer is composed of a non-magnetic layer, a ferromagnetic layer and an anti-ferromagnetic layer disposed on the first ferromagnetic layer in this order.