Nec Corporation

Eizo Fukami

Kazuhiko Hayashi

Masafumi Nakada

Nobuyuki Ishiwata

Kiyokazu Nagahara

Keishi Ohashi

Hiroaki Honjo

Hiroaki Honjou

Shinsaku Saitoh

Atsushi Kamijo

Kunihiko Ishihara

Hisanao Tsuge

Junichi Fujikata

Shigeru Mori

Tamaki Toba

A magnetoresistive effect sensor uses a shielded-type magnetoresistive effect element using a magnetoresistive effect film formed by a basic configuration of a combination of a free layer, a barrier layer formed on the free layer, and a fixed layer formed on the barrier layer, wherein a sensing current flows substantially perpendicular to the magnetoresistive effect film, and wherein an amorphous material or a microcrystalline material is used in a lower shield.

Magnetoresistive effect sensor with barrier layer smoothed by composition of lower shield layer

A magnetoresistive effect element which is easy to manufacture and in which a sense current is prevented from bypassing a barrier layer is provided. Also provided are a method for manufacturing the element and a magnetic recording apparatus utilizing the element. This magnetoresistive effect element utilizes an MTJ film which comprises, for forming its basic structure, a free layer, a barrier layer, a pinned layer and a pinning layer, wherein an oxide or a nitride layer is formed by oxidizing or nitriding metallic materials constituting the pinned layer and pinning layer.

Magnetoresistive effect element having a ferromagnetic tunnel junction film with an oxide or nitride of a metallic material

In a production process of an MR head using the tunnel junction film basically consisting of a free layer, a barrier layer, and a pinned layer, the resistance between the free layer and the pined layer reduced beforehand and increased afterward up to a resistance value necessary when actually used. While the resistance between the free layer and the pinned layer is low, current can easily flow, suppressing charge up, thus preventing insulation destruction of the barrier layer. This significantly increases a production yield of a recording/reproduction head using a ferromagnetic tunnel junction element.

Magnetoresistive head production method

A magnetoresistive effect head which is easy to manufacture and in which a sense current is prevented from bypassing a barrier layer is provided. Also provided are a method for manufacturing the head and a magnetic recording apparatus utilizing the head. This magnetoresistive effect head utilizes an MTJ film which comprises, for forming its basic structure, a free layer, a barrier layer, a pinned layer and a pinning layer, wherein an oxide or a nitride layer is formed by oxidizing or nitriding metallic materials constituting the pinned layer and pinning layer.

Magnetic head with a tunnel junction including metallic material sandwiched between one of an oxide and a nitride of the metallic material

A magnetoresistive head whose operation depends on a magnetoresistive effect is configured using a ferromagnetic tunnel junction (MTJ) film, which is arranged between a lower electrode and an upper electrode. The ferromagnetic tunnel junction film is basically configured using a set of a free layer, a barrier layer and a fixing layer, which are sequentially formed and laminated on the lower electrode. Herein, the ferromagnetic tunnel junction film is designed to avoid electrostatic destruction in manufacture by prescribed measures. For example, the barrier layer is reduced in thickness at a terminal portion as compared with a center portion. Or, the barrier layer has a defect at the terminal portion. In addition, it is possible to provide a conductor in connection with the barrier layer in proximity to its terminal portion. Further, it is possible to attach re-adhesive substance, which is produced by milling for patterning of the ferromagnetic tunnel junction film, to a specific terminal surface of the ferromagnetic tunnel junction film which is opposite to an ABS plane. Those measures provide a bypass allowing overcurrent release between the free layer and fixing layer. Moreover, adjustment milling or plasma oxidation is employed to control an amount of the re-adhesive substance being attached to the terminal surface of the ferromagnetic tunnel junction film. Thus, by adequately optimizing the amount of the re-adhesive substance, it is possible to improve yield in manufacturing the magnetoresistive heads.

MAGNETORESISTIVE HEAD HAVING FERROMAGNETIC TUNNEL JUNCTION FILM WITH A SMALLER RESISTANCE AT A TERMINAL PORTION THAN A CENTRAL PORTION, MAGNETIC RESISTANCE DETECTION SYSTEM WITH THE MAGNETORESISTIVE HEAD AND A MAGNETIC STORAGE SYSTEM USING IT

A magnetoresistance element includes a lower electrode layer, a magnetoresistance effect layer, an upper electrode layer and a lower electrode anti-erosion/flaking layer. The lower electrode anti-erosion/flaking layer, which is formed before a photoresist layer remaining on the patterned lower electrode layer is removed, is formed around the lower electrode layer so that its edge facing the lower electrode layer will be in contact with the edge of the lower electrode layer. By use of the lower electrode anti-erosion/flaking layer, the edge of the lower electrode layer is protected from being exposed to a release agent containing a dissolved photoresist in a photoresist layer removal step (when the photoresist layer remaining on the patterned lower electrode layer is removed), thereby the increase of roughness of the edge of the lower electrode layer due to erosion/flaking of the edge in the photoresist removal step can be avoided, and thereby electrical shorts between the upper electrode layer and the lower electrode layer can be eliminated, and thereby a magnetoresistance element of high sensitivity and high performance can be obtained and manufacturing yield of the magnetoresistance elements can be improved.

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Tokyo, Japan

Eizo Fukami