Examination method for cpp-type magnetoresistance effect element having two free layers

Abstract

An examination method is structured, with respect to a magnetization direction of an orthogonalizing bias function part formed on a posterior part of an magnetoresistance (MR) effect element, of changing the magnetization direction of the orthogonalizing bias function part between a first magnetization forming mode, wherein the magnetization direction is from the anterior side of the element to the posterior side thereof, and a second magnetization forming mode, wherein the magnetization direction is from the posterior side of the element to the anterior side thereof, measuring the output waveform of the element in response to an external magnetic field for each magnetization forming mode and checking the state of the output waveforms of both modes in order to examine whether or not the magnetization directions of the first magnetic layer and the second magnetic layer, both of which functions as free layers, are antiparallel to each other in the track width direction before the orthogonalizing bias function part starts functioning. With the structure, it is realized to easily examine whether or not the magnetization directions of two free layers have surely been made antiparallel to each other before operating the orthogonalizing bias function part of an element.

Description

technical field [0001] The present invention relates to an inspection method of a CPP type magnetoresistance effect element having two free layers, and particularly relates to an inspection method as follows: In the element of the orthogonal bias functional part that is affected by the substantially orthogonal action, check whether the magnetization directions of the two free layers are reliably antiparallel in the state before the orthogonal bias functional part functions state. Background technique [0002] In recent years, along with the high recording density of hard disks (HDDs), it is required to improve the performance of thin-film magnetic heads. As a thin-film magnetic head, a compound-type thin-film magnetic head is widely used. This composite-type thin-film magnetic head adopts a reproduction head with a magnetoresistive effect element (hereinafter also referred to as MR (Magneto-resistive) element exclusively for reading) and a write-only magnetic head. A struc...

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Problems solved by technology

Due to the narrow track of the regenerative element and the accompanying shortening of the element height, the area of ​​the element is reduced. However, in the existing structure, since the heat dissipation efficiency decreases with the reduction of the area, there are problems as follows: from reliability point of view, the operating current is limited

[0018] However, the actual situation is that there is no inspection method that can reliably ensure that the magnetization directions of the two ferromagnetic layers (free layers) become antiparallel along the track width direction.

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