JPH10222817A

JPH10222817A - Magneto-resistive sensor

Info

Publication number: JPH10222817A
Application number: JP2384097A
Authority: JP
Inventors: Katsuro Watanabe; 克朗渡辺; Yoshio Suzuki; 良夫鈴木; Yoshihiro Hamakawa; 佳弘濱川
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 1997-02-06
Filing date: 1997-02-06
Publication date: 1998-08-21

Abstract

PROBLEM TO BE SOLVED: To provide a magneto-resistive sensor capable of stably obtaining a regenerative waveform with large sensitivity and excellent symmetry. SOLUTION: A first magnetic sensor film 21 and a second magnetic sensor film 22 are laminated films respectively provided with first ferromagnetic layers 13, 16 rotating magnetization according to a magnetic field from a recording medium, second ferromagnetic layers 11, 18 fixing the magnetization and non- magnetic layers 12, 19 arranged between them. At this time, the magnetization of the second ferromagnetic layers 11, 18 are fixed oppositely to each other beforehand. Electrode pairs 37, 39 are arranged on respective magnetic sensor films 21, 22. The electric resistance changes of the magnetic sensor films 21, 22 are detected by circuits 504, 504, and by obtaining their difference by the circuit 505, the anisotropic magneto-resistive effects of the magnetic sensor films 21, 22 are canceled, and the symmetry of output waveforms by a giant magneto-resistive effect is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は磁気的に記録された
情報を再生する磁気トランスデューサに係り、特に線形
性に優れ、感度が高い磁気抵抗センサに関するものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic transducer for reproducing magnetically recorded information, and more particularly to a magnetoresistive sensor having excellent linearity and high sensitivity.

【０００２】[0002]

【従来の技術】磁気ディスク装置のダウンサイジング化
に伴い、面記録密度が急速に向上し、高い記録密度の磁
気記録面からでも情報を読出すことができる磁気抵抗セ
ンサ、すなわち磁気抵抗効果型ヘッド（ＭＲヘッド）が
実用化されている。現在使われているＭＲヘッドは、19
75年出版のアイイーイーイートランザクションオン
マグネティクス MAG-11巻の1039ページに詳細に説明さ
れている異方性磁気抵抗効果に基づき作動するものであ
り、その電気抵抗は、磁気抵抗センサ膜内の磁化の方向
と電流の方向のなす角度θの余弦の２乗（cos²θ）で変
化することが知られている。2. Description of the Related Art With downsizing of a magnetic disk drive, the areal recording density is rapidly improved, and a magnetoresistive sensor capable of reading information from a magnetic recording surface having a high recording density, that is, a magnetoresistive head. (MR head) has been put to practical use. Currently used MR heads are 19
It operates based on the anisotropic magnetoresistance effect described in detail on page 1039 of IAI Transaction on Magnetics MAG-11, published in 1975, and its electrical resistance is determined by the resistance within the magnetoresistive sensor film. It is known that it changes by the square of the cosine of the angle θ between the direction of magnetization and the direction of current (cos ² θ).

【０００３】数Ｇb/in² 以上の面記録密度になると、異
方性磁気抵抗効果を用いた磁気抵抗センサでは感度不足
が予想されるため、1989年出版のフィジカルレビュー
ビー 39巻の4828ページに紹介されているような、非
磁性導電層を介して積層された２層の強磁性薄膜層の互
いの磁化の方向のなす角度によって電気抵抗が変化する
巨大磁気抵抗効果を用いた磁気抵抗センサの研究開発が
盛んに行われている。At an areal recording density of several Gb / in ² or more, the sensitivity of a magnetoresistive sensor using the anisotropic magnetoresistance effect is expected to be insufficient. Therefore, Physical Review Be published in 1989, Vol. As introduced, a magnetoresistive sensor using the giant magnetoresistance effect in which the electric resistance changes depending on the angle between the directions of magnetization of two ferromagnetic thin film layers stacked via a nonmagnetic conductive layer. R & D is actively conducted.

【０００４】巨大磁気抵抗効果を用いた磁気抵抗センサ
の一つとして、特開平４−３５８３１０号公報には、ス
ピンバルブ構造と呼ばれる構造が記されている。これ
は、反強磁性薄膜層によって磁化が特定の方向に固定さ
れた第１の強磁性薄膜層と、非磁性導電層を介して第１
の強磁性薄膜層に積層された第２の強磁性薄膜層とで構
成されており、第１の強磁性薄膜層の磁化と第２の強磁
性薄膜層の磁化の相対的な角度によって電気抵抗が変化
するものである。As one of the magnetoresistive sensors using the giant magnetoresistive effect, a structure called a spin valve structure is described in Japanese Patent Application Laid-Open No. 4-358310. This is because the first ferromagnetic thin film layer whose magnetization is fixed in a specific direction by the antiferromagnetic thin film layer and the first ferromagnetic thin film layer via the nonmagnetic conductive layer.
And a second ferromagnetic thin film layer laminated on the first ferromagnetic thin film layer. The electric resistance is determined by the relative angle between the magnetization of the first ferromagnetic thin film layer and the magnetization of the second ferromagnetic thin film layer. Changes.

【０００５】また、特開平６−２６７０２９および特開
平７−８５４２６号公報には、バルクハウゼンノイズを
低減するために、反強磁性膜を挟んで、２つの巨大磁気
抵抗効果素子を積層し、これに一対の電極から電流を流
すことにより、２つの巨大磁気抵抗効果素子の合成抵抗
を検出する磁気抵抗効果型ヘッドが記載されている。こ
の磁気抵抗効果型ヘッドでは、一方の巨大磁気抵抗効果
素子に記録媒体から印加される磁界と、他方の巨大磁気
抵抗効果素子に記録媒体から印加される磁界とが、互い
に同極性である場合には、両者の電気抵抗変化は相殺し
あうため、出力は得られないが、記録媒体の磁化が反転
している領域では、２つの巨大磁気抵抗効果素子に印加
される磁界が互いに逆極性になり、両者の抵抗変化が強
め合って出力が得られる構成である。In order to reduce Barkhausen noise, JP-A-6-267029 and JP-A-7-85426 disclose two giant magnetoresistive elements with an antiferromagnetic film interposed therebetween. Describes a magnetoresistive head for detecting the combined resistance of two giant magnetoresistive elements by passing a current from a pair of electrodes. In this magnetoresistive head, a magnetic field applied to one giant magnetoresistive element from the recording medium and a magnetic field applied to the other giant magnetoresistive element from the recording medium have the same polarity. Does not produce an output because the electrical resistance changes of the two cancel each other out, but in the region where the magnetization of the recording medium is reversed, the magnetic fields applied to the two giant magnetoresistive elements have opposite polarities. In this configuration, an output is obtained by strengthening the resistance changes between the two.

【０００６】[0006]

【発明が解決しようとする課題】従来の特開平４−３５
８３１０公報の磁気抵抗センサの構成は、再生波形を測
定すると、対称性のよい再生波形が得られないという問
題がある。ここで、対称性のよい再生波形とは、符号の
異なる情報を読出したときに、正負の波形のピーク値が
等しい波形のことを言う。このように、再生波形の対称
性を損なう原因は、巨大磁気抵抗効果に異方性磁気抵抗
効果が重畳しているためであると考えられる。SUMMARY OF THE INVENTION Conventional Japanese Patent Application Laid-Open No. 4-35
The configuration of the magnetoresistive sensor disclosed in the 8310 publication has a problem that when a reproduced waveform is measured, a reproduced waveform with good symmetry cannot be obtained. Here, a reproduced waveform having good symmetry means a waveform having the same peak value of positive and negative waveforms when information having different signs is read. It is considered that the reason why the symmetry of the reproduced waveform is lost is that the giant magnetoresistance effect is superimposed on the anisotropic magnetoresistance effect.

【０００７】また、特開平６−２６７０２９および特開
平７−８５４２６号公報記載の磁気抵抗効果型ヘッド
は、バルクハウゼンノイズを減少させることを目的とし
た構成であるため、異方性磁気抵抗効果が重畳すること
による再生波形の対称性の改善については考慮されてい
ない。このため、差動動作ではあるが、２つの磁気抵抗
効果素子の合成抵抗を１組の電極で検出する構成である
ため、異方性磁気抵抗効果を相殺することはできず、異
方性磁気抵抗効果が重畳した巨大磁気抵抗効果の出力を
そのまま単純に倍にした再生出力となる。また、この構
成では、記録媒体の磁化が反転している領域のみで再生
出力が得られる。Further, the magnetoresistive head described in JP-A-6-267029 and JP-A-7-85426 is designed to reduce Barkhausen noise. No consideration is given to improving the symmetry of the reproduced waveform due to the superposition. For this reason, although the operation is a differential operation, the combined resistance of the two magnetoresistive elements is detected by one set of electrodes. The output of the giant magnetoresistive effect on which the resistance effect is superimposed is simply a doubled reproduction output. Further, in this configuration, a reproduction output can be obtained only in the region of the recording medium where the magnetization is reversed.

【０００８】本発明の目的は、巨大磁気抵抗効果を用い
た磁気抵抗センサであって、異方性磁気抵抗効果の影響
を取り除き、対称性の良い再生波形が安定して得られる
磁気抵抗センサを提供することにある。An object of the present invention is to provide a magnetoresistive sensor using a giant magnetoresistive effect, which eliminates the effects of the anisotropic magnetoresistive effect and can stably produce a reproduced waveform with good symmetry. To provide.

【０００９】[0009]

【課題を解決するための手段】上記目的を達成するため
に、本発明によれば以下のような磁気抵抗センサが提供
される。According to the present invention, there is provided the following magnetoresistive sensor.

【００１０】すなわち、記録媒体からの磁界によって電
気抵抗変化の生じる第１の磁気センサ膜および第２の磁
気センサ膜と、前記第１の磁気センサ膜の電気抵抗変化
を検出するための第１の電極対と、前記第２の磁気セン
サ膜の電気抵抗変化を検出するための第２の電極対と、
前記第１の電極対から検出された電気抵抗変化と第２の
電極対から検出された電気抵抗変化との差を求める電気
回路とを有し、第１の磁気センサ膜および第２の磁気セ
ンサ膜は、それぞれ、記録媒体からの磁界に応じて磁化
の回転する第１の強磁性層と、磁化の固定された第２の
強磁性層と、前記第１の強磁性層と第２の強磁性層との
間に配置された非磁性層とを有する積層膜であり、前記
第１の磁気センサ膜の第２の強磁性層の磁化は、前記第
２の磁気センサ膜の第２の強磁性層の磁化が固定されて
いる方向とは異なる向きに固定されている磁気抵抗セン
サである。That is, a first magnetic sensor film and a second magnetic sensor film whose electric resistance changes due to a magnetic field from a recording medium, and a first magnetic sensor film for detecting the electric resistance change of the first magnetic sensor film. An electrode pair, a second electrode pair for detecting a change in electrical resistance of the second magnetic sensor film,
An electric circuit for obtaining a difference between the electric resistance change detected from the first electrode pair and the electric resistance change detected from the second electrode pair, the first magnetic sensor film and the second magnetic sensor The films are a first ferromagnetic layer whose magnetization rotates in response to a magnetic field from a recording medium, a second ferromagnetic layer having a fixed magnetization, and a first ferromagnetic layer and a second ferromagnetic layer, respectively. And a non-magnetic layer disposed between the magnetic layer and a non-magnetic layer, wherein the magnetization of the second ferromagnetic layer of the first magnetic sensor film is the second strong magnetic layer of the second magnetic sensor film. The magnetoresistive sensor is fixed in a direction different from the direction in which the magnetization of the magnetic layer is fixed.

【００１１】[0011]

【発明の実施の形態】巨大磁気抵抗効果を利用する磁気
抵抗センサにおいて、再生波形の対称性を損なう原因
は、巨大磁気抵抗効果に異方性磁気抵抗効果が重畳して
いることにある。よって、大きな感度と対称性の良い再
生波形を安定して得るためには、大きな磁気抵抗変化率
が得られる巨大磁気抵抗効果を活かすとともに、異方性
磁気抵抗効果の影響を小さくすることが必要となる。DESCRIPTION OF THE PREFERRED EMBODIMENTS In a magnetoresistive sensor utilizing the giant magnetoresistance effect, the cause of impairing the symmetry of the reproduced waveform is that the giant magnetoresistance effect is superimposed on the anisotropic magnetoresistance effect. Therefore, in order to stably obtain a reproduced waveform with high sensitivity and symmetry, it is necessary to utilize the giant magnetoresistance effect that provides a large magnetoresistance change rate and reduce the influence of the anisotropic magnetoresistance effect. Becomes

【００１２】一般的な、図１０のようなスピンバルブ構
造の磁気抵抗センサにおいて、第１の強磁性薄膜層１１
の磁化の方向を素子高さ方向２８に固定し、外部磁界に
対して自由に回転する第２の強磁性薄膜層１３の誘導異
方性の方向を、第１の強磁性薄膜層１１の磁化の方向と
は直交するトラック幅方向２９とした場合、巨大磁気抵
抗効果のみを考えると、外部磁界がゼロのときの出力
は、最大出力の１／２になる。しかも、外部磁界に対す
る応答の線形性が良いため、対称性の良い再生波形が得
られる。In a general magnetoresistive sensor having a spin valve structure as shown in FIG.
Is fixed in the element height direction 28, and the direction of the induced anisotropy of the second ferromagnetic thin film layer 13 that freely rotates with respect to an external magnetic field is changed to the magnetization of the first ferromagnetic thin film layer 11. When the external magnetic field is zero, the output is の of the maximum output, considering only the giant magnetoresistance effect. Moreover, since the linearity of the response to the external magnetic field is good, a reproduced waveform with good symmetry can be obtained.

【００１３】しかしながら、実際に、図１０のスピンバ
ルブ構造の磁気抵抗センサの磁気抵抗効果曲線を測定す
ると、図１１のように、外部磁界ゼロにおける出力は、
最大出力の１／２よりも大きく、しかも、傾きも緩やか
である。このため、磁気ディスク装置に組み込んだ場合
に、出力は小さく、再生波形の対称性を確保することが
できない。これは、この磁気センサにおいて、巨大磁気
抵抗効果に、異方性磁気抵抗効果が重畳しているためで
ある。なお、磁気抵抗効果曲線の測定を行った磁気抵抗
センサは、第２の強磁性薄膜層１３を厚さ１０ｎｍのＮ
ｉ₈₁Ｆｅ₁₉とし、磁化の配置を図１０のように向けたも
のである。また、素子の形状は、素子高さが１.２μ
ｍ、トラック幅が１.４μｍであり、シールド層は設け
ていない。However, when the magnetoresistive effect curve of the magnetoresistive sensor having the spin valve structure shown in FIG. 10 is actually measured, as shown in FIG.
It is larger than 1/2 of the maximum output, and the inclination is gentle. For this reason, when incorporated in a magnetic disk device, the output is small and the symmetry of the reproduced waveform cannot be ensured. This is because in this magnetic sensor, the giant magnetoresistance effect is superimposed on the anisotropic magnetoresistance effect. The magnetoresistive sensor for which the magnetoresistive effect curve was measured is a second ferromagnetic thin film layer 13 having a thickness of 10 nm.
i ₈₁ Fe ₁₉ and the orientation of magnetization is oriented as shown in FIG. The shape of the element is such that the element height is 1.2 μm.
m, the track width is 1.4 μm, and no shield layer is provided.

【００１４】また、巨大磁気抵抗効果と異方性磁気抵抗
効果を考慮して、ランダウ − リフシッツ − ギルバー
ト方程式に基づくシミュレーションを行った。その結
果を図１２に示す。図１２の曲線は、異方性磁気抵抗効
果による出力（ＡＭＲ）と巨大磁気抵抗効果による出力
（ＧＭＲ）の比が０.２の場合のそれぞれの出力と両者
の和（ＧＭＲ＋ＡＭＲ）を示したものである。図１２の
曲線の形状が、図１１の磁気抵抗効果曲線とよく一致し
ており、図１１の曲線はＧＭＲ＋ＡＭＲに相当してい
ることがわかる。図１２の曲線から明らかなように、Ｇ
ＭＲの曲線は、外部磁界ゼロ付近で急峻な傾きを示して
いるが、これにＡＭＲが加わることにより磁気抵抗効果
曲線がシフトしたように見える曲線となり、外部磁界ゼ
ロ近傍において、傾きが緩やかになるとともに、線形性
が悪くなる。Further, a simulation based on the Landau-Lifshitz-Gilbert equation was performed in consideration of the giant magnetoresistance effect and the anisotropic magnetoresistance effect. FIG. 12 shows the result. The curves in FIG. 12 show the respective outputs and the sum (GMR + AMR) when the ratio of the output (AMR) due to the anisotropic magnetoresistive effect and the output (GMR) due to the giant magnetoresistive effect is 0.2. It is. The shape of the curve in FIG. 12 matches well with the magnetoresistance effect curve in FIG. 11, and it can be seen that the curve in FIG. 11 corresponds to GMR + AMR. As is apparent from the curve in FIG.
The MR curve shows a steep slope near the external magnetic field of zero. However, when AMR is added to the curve, the magnetoresistive effect curve appears to be shifted, and the slope becomes gentle near the external magnetic field of zero. At the same time, the linearity deteriorates.

【００１５】よって、スピンバルブ構造の磁気抵抗セン
サにおいて、再生波形の対称性を向上させるためには、
異方性磁気抵抗効果の低減が重要である。Therefore, in order to improve the symmetry of the reproduction waveform in the magnetoresistive sensor having the spin valve structure,
It is important to reduce the anisotropic magnetoresistance effect.

【００１６】異方性磁気抵抗効果を小さくする手段の一
つとして、磁気センサ膜を構成する強磁性薄膜層に非磁
性元素を添加する方法が知られている。しかし、この方
法では異方性磁気抵抗効果を小さくすると同時に巨大磁
気抵抗効果も小さくしてしまい、出力の低下を招く。ま
た、異方性磁気抵抗効果をなくすことはできないため、
再生波形の非対称性は改善されないので、好ましい方法
ではないと考えられる。As one of means for reducing the anisotropic magnetoresistance effect, there is known a method of adding a nonmagnetic element to a ferromagnetic thin film layer constituting a magnetic sensor film. However, in this method, the giant magnetoresistance effect is also reduced at the same time as the anisotropic magnetoresistance effect is reduced, resulting in a decrease in output. Also, since the anisotropic magnetoresistance effect cannot be eliminated,
Since the asymmetry of the reproduced waveform is not improved, it is not considered to be a preferable method.

【００１７】そこで、本発明では、２つのスピンバルブ
構造の磁気センサ膜を用意し、磁気センサ膜から得られ
た電気信号の差をとることにより、異方性磁気抵抗効果
による電気抵抗変化を相殺すると同時に、巨大磁気抵抗
効果による電気抵抗変化を足し合わせて、再生波形を改
善させるとともに、再生信号の感度を向上させる。Therefore, in the present invention, a magnetic sensor film having two spin-valve structures is prepared, and a difference between electric signals obtained from the magnetic sensor films is taken to cancel a change in electric resistance due to an anisotropic magnetoresistance effect. At the same time, the change in electric resistance due to the giant magnetoresistance effect is added to improve the reproduction waveform and the sensitivity of the reproduction signal.

【００１８】以下、本発明の一実施の形態について説明
する。Hereinafter, an embodiment of the present invention will be described.

【００１９】本実施の形態の磁気抵抗センサは、図１に
示すように、絶縁層１４を挟んで積層された第１の磁気
センサ膜２１と第２の磁気センサ膜２２とを有する。第
１の磁気センサ膜２１は、第１の非磁性導電層２１を間
に挟んで重ねられた、第１の強磁性薄膜層１１と第２の
強磁性薄膜層１３とを含む。第２の磁気センサ膜２２
は、第２の非磁性導電層１９を間に挟んで重ねられた、
第３の強磁性薄膜層１６と第４の強磁性薄膜層１８とを
含む。また、図１には示していないが、第１の磁気セン
サ膜２１ならびに第２の磁気センサ膜２２には、それぞ
れの磁気センサ膜の電気抵抗変化を検出するために、そ
れぞれ一対の電極が配置されている。さらに、各電極対
は、電気抵抗変化を検出する回路と、それらの電気抵抗
変化の差を求めるための、差動アンプ等の電気回路（不
図示）に接続される。As shown in FIG. 1, the magnetoresistive sensor according to the present embodiment has a first magnetic sensor film 21 and a second magnetic sensor film 22 stacked with an insulating layer 14 interposed therebetween. The first magnetic sensor film 21 includes a first ferromagnetic thin film layer 11 and a second ferromagnetic thin film layer 13 stacked with the first nonmagnetic conductive layer 21 interposed therebetween. Second magnetic sensor film 22
Are stacked with the second nonmagnetic conductive layer 19 interposed therebetween.
It includes a third ferromagnetic thin film layer 16 and a fourth ferromagnetic thin film layer 18. Although not shown in FIG. 1, a pair of electrodes is disposed on each of the first magnetic sensor film 21 and the second magnetic sensor film 22 in order to detect a change in electric resistance of each magnetic sensor film. Have been. Further, each electrode pair is connected to a circuit for detecting a change in electric resistance and an electric circuit (not shown) such as a differential amplifier for obtaining a difference between the electric resistance changes.

【００２０】ここで、第１の強磁性薄膜層１１の磁化お
よび第４の強磁性薄膜層１８の磁化は、素子高さ方向２
８に沿って互いに逆向きに固定されている。また、第２
の強磁性薄膜層１３の磁気異方性および第３の強磁性薄
膜層１６の磁気異方性は、トラック幅方向２９に誘導さ
れており、その磁化は、いずれも外部磁界によってトラ
ック幅方向２９を中心に自由に回転する。Here, the magnetization of the first ferromagnetic thin-film layer 11 and the magnetization of the fourth ferromagnetic thin-film layer 18 are different from each other in the element height direction 2.
8 are fixed in opposite directions. Also, the second
The magnetic anisotropy of the ferromagnetic thin film layer 13 and the magnetic anisotropy of the third ferromagnetic thin film layer 16 are induced in the track width direction 29. Rotate freely around.

【００２１】このような図１の磁気抵抗センサに、信号
検出電流をトラック幅方向２９に流したときに、第１の
磁気センサ膜２１及び第２の磁気センサ膜２２のそれぞ
れの電極対から検出される磁気抵抗効果曲線をシミュレ
ーションにより求めた結果を、それぞれ図２（ａ）及び
（ｂ）に示す。異方性磁気抵抗効果は、磁化の方向と信
号検出電流の方向とのなす角度θに対しｃｏｓ²θで変
化するものであるから、第１の磁気センサ膜２１と第２
の磁気センサ膜２２でほぼ同様の磁気抵抗効果曲線を示
す。一方、巨大磁気抵抗効果は、２つの強磁性薄膜層の
磁化の方向のなす角度φに対しｃｏｓφで変化するもの
であるから、第１の磁気センサ膜２１と第２の磁気セン
サ膜２２とでは、磁界に対する応答は逆になる。これら
の差を、電気回路によって検出すると、図３のようにな
る。すなわち、異方性磁気抵抗効果が相殺されるため、
磁気抵抗効果曲線の差動出力には、異方性磁気抵抗効果
による影響が殆ど見られず、磁界ゼロ近傍で傾きが急で
あり、線形性もよくなる。よって、本実施の形態の磁気
抵抗センサを用いることにより、大きな感度と対称性の
良い再生波形が得られることがわかる。When a signal detection current flows in the magnetoresistive sensor of FIG. 1 in the track width direction 29, detection is performed from the respective electrode pairs of the first magnetic sensor film 21 and the second magnetic sensor film 22. FIGS. 2A and 2B show the results obtained by simulating the magnetoresistive effect curves obtained. Since the anisotropic magnetoresistance effect changes by cos ² θ with respect to the angle θ between the direction of magnetization and the direction of the signal detection current, the first magnetic sensor film 21 and the second
Of the magnetic sensor film 22 of FIG. On the other hand, since the giant magnetoresistance effect changes by cos φ with respect to the angle φ between the directions of magnetization of the two ferromagnetic thin film layers, the first magnetic sensor film 21 and the second magnetic sensor film 22 , The response to the magnetic field is reversed. When these differences are detected by an electric circuit, the result is as shown in FIG. That is, since the anisotropic magnetoresistance effect is offset,
The differential output of the magnetoresistive effect curve shows almost no influence by the anisotropic magnetoresistive effect, has a steep slope near zero magnetic field, and has good linearity. Therefore, it can be seen that by using the magnetoresistive sensor of the present embodiment, a reproduced waveform with high sensitivity and good symmetry can be obtained.

【００２２】なお、図２（ａ），（ｂ）において、異方
性磁気抵抗効果による磁気抵抗効果曲線が、磁界に対し
てわずかに非対称な形になっているのは、第１の磁気抵
抗センサ膜２１の第２の強磁性薄膜層１３、ならびに第
２の磁気抵抗センサ膜２２の第３の強磁性薄膜層１６の
磁化が、記録媒体から磁界を受けていない状態で、トラ
ック幅方向２９からわずかにずれているためである。こ
れは、第１の強磁性薄膜層１１および第４の強磁性薄膜
層１８の端部に発生する磁極によって生じた磁界が、第
２、第３の強磁性薄膜層１３、１６に入り込み、第２、
第３の強磁性薄膜層１３、１６の磁化をわずかに傾斜さ
せる現象による。この現象は、スピンバルブ構造の磁気
抵抗センサ特有の現象である。In FIGS. 2A and 2B, the magnetoresistive effect curve due to the anisotropic magnetoresistive effect is slightly asymmetric with respect to the magnetic field. When the magnetizations of the second ferromagnetic thin film layer 13 of the sensor film 21 and the third ferromagnetic thin film layer 16 of the second magnetoresistive sensor film 22 are not receiving a magnetic field from the recording medium, the magnetization in the track width direction 29 Because it is slightly off. This is because the magnetic field generated by the magnetic poles generated at the end portions of the first ferromagnetic thin film layer 11 and the fourth ferromagnetic thin film layer 18 enters the second and third ferromagnetic thin film layers 13 and 16, and 2,
This is due to the phenomenon that the magnetization of the third ferromagnetic thin film layers 13 and 16 is slightly inclined. This phenomenon is peculiar to a magnetoresistive sensor having a spin valve structure.

【００２３】また、磁気抵抗センサにおいては、磁気抵
抗センサが記録媒体に衝突した際に、摩擦による温度上
昇のため、出力にノイズがのる現象、いわゆるサーマル
アスピリティーが生じることが知られている。衝突によ
る温度上昇は、第１および第２の磁気センサ膜について
同様に生じるため、第１の磁気センサ膜の出力と、第２
の磁気センサ膜の出力との差をとる本発明の磁気抵抗セ
ンサでは、サーマルアスピリティーによるノイズを打ち
消すことができる。In a magnetoresistive sensor, it is known that when the magnetoresistive sensor collides with a recording medium, a phenomenon in which noise is added to the output due to a temperature rise due to friction, a so-called thermal spirit, occurs. . Since the temperature increase due to the collision occurs similarly for the first and second magnetic sensor films, the output of the first magnetic sensor film and the second
In the magnetoresistive sensor of the present invention that takes a difference from the output of the magnetic sensor film of the above, noise due to thermal spirit can be canceled.

【００２４】上述してきたように、本発明の磁気抵抗セ
ンサは、逆向きに磁化を固定した２組の磁気センサ膜を
用い、これらの磁気センサ膜の電気的な出力の差を電気
回路によって求める構成であるため、異方性磁気抵抗効
果を相殺し、巨大磁気抵抗効果を重ね合うことにより、
出力が大きく、対称性の良い再生波形が得られる。ま
た、サーマルアスピリティーによるノイズを打ち消すこ
とができ、ノイズの少ない再生波形が得られる。As described above, the magnetoresistive sensor of the present invention uses two sets of magnetic sensor films whose magnetizations are fixed in opposite directions, and determines the difference between the electrical outputs of these magnetic sensor films by an electric circuit. Because of the configuration, the anisotropic magnetoresistance effect is canceled and the giant magnetoresistance effect is superimposed,
A reproduced waveform having a large output and good symmetry can be obtained. Also, noise due to thermal spirit can be canceled, and a reproduced waveform with less noise can be obtained.

【００２５】なお、本発明の磁気抵抗センサの層構成
は、図１の構成に限定されるものではなく、他の構成で
も良い。例えば、図４のように、絶縁性反強磁性薄膜層
４１５を挟んで、第１の磁気センサ膜４２１と第２の磁
気センサ膜４２２とを積層した構成にすることができ
る。電極対（不図示）は、第１および第２の磁気センサ
膜４２１、４２２それぞれに配置し、各電極対は、それ
ぞれの電気抵抗の変化を検出する回路と、それらの出力
の差を求める回路に接続する。The layer structure of the magnetoresistive sensor of the present invention is not limited to the structure shown in FIG. 1, but may be another structure. For example, as shown in FIG. 4, a structure in which the first magnetic sensor film 421 and the second magnetic sensor film 422 are stacked with the insulating antiferromagnetic thin film layer 415 interposed therebetween can be employed. An electrode pair (not shown) is disposed on each of the first and second magnetic sensor films 421 and 422. Each electrode pair has a circuit for detecting a change in electric resistance and a circuit for obtaining a difference between their outputs. Connect to

【００２６】第１の磁気センサ膜４２１は、順に積層さ
れた、第１の強磁性薄膜層４１１、第１の非磁性導電層
４１２、第２の強磁性薄膜層４１３を含む。第１の磁気
センサ膜４２１では、第２の強磁性薄膜層４１３の磁化
４２４を、絶縁性反強磁性薄膜層４１５との交換結合に
よって素子の高さ方向２８に固定し、第１の強磁性薄膜
層４１１の磁化４２３を記録媒体からの磁界によってト
ラック幅方向２９を中心に自由に回転させる。The first magnetic sensor film 421 includes a first ferromagnetic thin film layer 411, a first nonmagnetic conductive layer 412, and a second ferromagnetic thin film layer 413, which are sequentially stacked. In the first magnetic sensor film 421, the magnetization 424 of the second ferromagnetic thin film layer 413 is fixed in the element height direction 28 by exchange coupling with the insulating antiferromagnetic thin film layer 415, and the first ferromagnetic thin film The magnetization 423 of the thin film layer 411 is freely rotated around the track width direction 29 by the magnetic field from the recording medium.

【００２７】一方、第２の磁気センサ膜４２２は、順に
積層された、第３の強磁性薄膜層４１６、非磁性スペー
サ層４１７、第４の強磁性薄膜層４１８、第２の非磁性
導電層４１９、第５の強磁性薄膜層４２０を含む。第２
の磁気センサ膜４２２では、第４の強磁性薄膜層４１８
の磁化４２６を、第３の強磁性薄膜層４１６の磁化４２
５と、適切な厚さのスペーサ層４１７を介して反強磁性
的に強く結合させることにより、素子の高さ方向２８に
固定する。第３の強磁性薄膜層４１６の磁化４２５は、
絶縁性反強磁性薄膜層４１５との交換結合により固定す
る。これにより、第２の磁気センサ膜４２２の第４の強
磁性薄膜層４１８の磁化４２６の方向を、第１の磁気セ
ンサ膜４２１の第２の強磁性薄膜層４１３の磁化４２４
の方向と逆向きにすることができる。また、第５の強磁
性薄膜層４２０の磁化４２７は、記録媒体からの磁界に
よってトラック幅方向２９を中心に自由に回転する。On the other hand, the second magnetic sensor film 422 is formed by sequentially stacking a third ferromagnetic thin film layer 416, a nonmagnetic spacer layer 417, a fourth ferromagnetic thin film layer 418, and a second nonmagnetic conductive layer. 419, including a fifth ferromagnetic thin film layer 420. Second
In the magnetic sensor film 422 of FIG.
Magnetization 426 of the third ferromagnetic thin film layer 416
5 is fixed in the height direction 28 of the element by strong antiferromagnetic coupling through a spacer layer 417 having an appropriate thickness. The magnetization 425 of the third ferromagnetic thin film layer 416 is
It is fixed by exchange coupling with the insulating antiferromagnetic thin film layer 415. Thereby, the direction of the magnetization 426 of the fourth ferromagnetic thin film layer 418 of the second magnetic sensor film 422 is changed to the magnetization 424 of the second ferromagnetic thin film layer 413 of the first magnetic sensor film 421.
In the opposite direction. Further, the magnetization 427 of the fifth ferromagnetic thin film layer 420 is freely rotated around the track width direction 29 by a magnetic field from the recording medium.

【００２８】図４の構成では、反強磁性層と強磁性層の
交換結合と、非磁性層を挟んだ２枚の強磁性層の反強磁
性的な結合とを利用することにより、第１の磁気センサ
膜４２１の第２の強磁性薄膜層４１３の磁化の方向と、
第２の磁気センサ膜４２２の第４の強磁性薄膜層４１８
の磁化の方向とを、互いに逆向きに固定することができ
る。これにより、磁化を固定するための処理が容易にな
り、製造工程を簡素化できるという利点がある。In the configuration shown in FIG. 4, the first coupling is realized by utilizing the exchange coupling between the antiferromagnetic layer and the ferromagnetic layer and the antiferromagnetic coupling between the two ferromagnetic layers sandwiching the nonmagnetic layer. The direction of magnetization of the second ferromagnetic thin film layer 413 of the magnetic sensor film 421 of FIG.
Fourth ferromagnetic thin film layer 418 of second magnetic sensor film 422
Can be fixed in the directions opposite to each other. Thereby, there is an advantage that the process for fixing the magnetization is facilitated and the manufacturing process can be simplified.

【００２９】以下，本発明による実施の形態の磁気セン
サについて、さらに具体的に説明する。Hereinafter, the magnetic sensor according to the embodiment of the present invention will be described more specifically.

【００３０】図５は、本発明の磁気抵抗センサの具体的
な断面図である。層構造の基本的な構成は、図１の磁気
センサと同様である。FIG. 5 is a specific sectional view of the magnetoresistive sensor of the present invention. The basic configuration of the layer structure is the same as that of the magnetic sensor of FIG.

【００３１】すなわち、非磁性基板１０の上には、順
に、反強磁性薄膜層３１、第１の強磁性薄膜層１１、第
１の非磁性導電層１２、第２の強磁性薄膜層１３、保護
膜３２が積層されている。これらの膜は、第１の磁気セ
ンサ膜２１を構成する。反強磁性薄膜層３１は、第１の
強磁性薄膜層１１の磁化を交換結合により固定するため
のものである。第１の磁気センサ膜２１の両側には、バ
ルクハウゼンノイズを抑制するために、第２の強磁性薄
膜層１３に縦バイアス磁界を印加する一対の縦バイアス
印加層３６が配置されている。一対の縦バイアス印加層
３６の上には、第１の磁気センサ膜２１に信号検出電流
を流すための一対の電極３７が配置されている。That is, the antiferromagnetic thin film layer 31, the first ferromagnetic thin film layer 11, the first nonmagnetic conductive layer 12, the second ferromagnetic thin film layer 13, the The protective film 32 is laminated. These films constitute the first magnetic sensor film 21. The antiferromagnetic thin film layer 31 is for fixing the magnetization of the first ferromagnetic thin film layer 11 by exchange coupling. On both sides of the first magnetic sensor film 21, a pair of vertical bias applying layers 36 for applying a vertical bias magnetic field to the second ferromagnetic thin film layer 13 are arranged in order to suppress Barkhausen noise. A pair of electrodes 37 for passing a signal detection current through the first magnetic sensor film 21 are arranged on the pair of vertical bias applying layers 36.

【００３２】これらの構成は、絶縁層１４で被覆され、
この上に、第２の磁気センサ膜２２が積層されている。
第２の磁気センサ膜２２は、順に積層された、下地膜３
３、第３の強磁性薄膜層１６、第２の非磁性導電層１
９、第４の強磁性薄膜層１８、反強磁性薄膜層３５、保
護膜３４から構成される。下地膜３３は、上に積層され
ていく薄膜層の結晶配向性を向上させるために配置され
ている。また、反強磁性薄膜層３５は、第４の強磁性薄
膜層１８の磁化を交換結合により固定するために配置さ
れている。第２の磁気センサ膜２２の両脇には、一対の
縦バイアス印加層３８、一対の電極３９が配置されてい
る。These configurations are covered with an insulating layer 14,
On this, the second magnetic sensor film 22 is laminated.
The second magnetic sensor film 22 is formed by sequentially laminating the base film 3
3, third ferromagnetic thin film layer 16, second nonmagnetic conductive layer 1
9, a fourth ferromagnetic thin film layer 18, an antiferromagnetic thin film layer 35, and a protective film 34. The base film 33 is disposed in order to improve the crystal orientation of the thin film layer stacked thereon. Further, the antiferromagnetic thin film layer 35 is arranged to fix the magnetization of the fourth ferromagnetic thin film layer 18 by exchange coupling. On both sides of the second magnetic sensor film 22, a pair of vertical bias applying layers 38 and a pair of electrodes 39 are arranged.

【００３３】各強磁性薄膜層１１、１３、１６、１８の
磁化の向きは、図１の磁気抵抗センサと同様である。す
なわち、第１の磁気センサ膜２１の第１の強磁性薄膜層
１１の磁化２３、ならびに、第２の磁気センサ膜２２の
第４の強磁性薄膜層１８の磁化２６は、素子の高さ方向
２８に平行で互いに逆向きに固定されている。この固定
は、図５の構成では、反強磁性薄膜層３１、３５との交
換結合によって成されている。また、第１の磁気センサ
膜２１の第２の強磁性薄膜層１３の磁化２４、ならび
に、第２の磁気センサ膜２２の第３の強磁性薄膜層１６
の磁化２５は、記録媒体からの磁界を受けていない場合
には、トラック幅方向２９に平行で同じ向きであり、記
録媒体からの磁界を受けると、その磁界の向きに応じて
回転する。The directions of magnetization of the ferromagnetic thin film layers 11, 13, 16, and 18 are the same as those of the magnetoresistive sensor of FIG. That is, the magnetization 23 of the first ferromagnetic thin film layer 11 of the first magnetic sensor film 21 and the magnetization 26 of the fourth ferromagnetic thin film layer 18 of the second magnetic sensor film 22 depend on the height of the element. 28 and fixed in opposite directions. This fixing is achieved by exchange coupling with the antiferromagnetic thin film layers 31, 35 in the configuration of FIG. Further, the magnetization 24 of the second ferromagnetic thin film layer 13 of the first magnetic sensor film 21 and the third ferromagnetic thin film layer 16 of the second magnetic sensor film 22
When no magnetic field is received from the recording medium, the magnetization 25 is parallel to the track width direction 29 and has the same direction. When a magnetic field is received from the recording medium, the magnetization 25 rotates according to the direction of the magnetic field.

【００３４】記録媒体からの磁界による第２の強磁性薄
膜層１３および第３の強磁性層１６の磁化１３、１６の
回転に伴う第１の磁気センサ膜２１および第２の磁気セ
ンサ膜２２の電気抵抗変化を検出するために、電極３７
および電極３９には、別個の電流源５０１、５０２と抵
抗変化検知回路５０３、５０４が接続されている。抵抗
変化検知回路５０３、５０４には、これらの検知した抵
抗変化の差を検出する回路５０５に接続され、出力が得
られる構成である。The rotation of the magnetizations 13 and 16 of the second ferromagnetic thin film layer 13 and the third ferromagnetic layer 16 by the magnetic field from the recording medium causes the first magnetic sensor film 21 and the second magnetic sensor film 22 to rotate. In order to detect a change in electric resistance, the electrode 37 is used.
The electrodes 39 are connected to separate current sources 501 and 502 and resistance change detection circuits 503 and 504, respectively. The resistance change detection circuits 503 and 504 are connected to a circuit 505 for detecting a difference between these detected resistance changes, and are configured to obtain an output.

【００３５】図１の磁気抵抗センサで説明したように、
本発明の磁気抵抗センサでは、第１および第２の磁気セ
ンサ膜２１、２２の各層うち、磁化を固定する強磁性薄
膜層１１、１８の磁化の向きを互いに逆向きし、しか
も、第１および第２の磁気センサ膜２１、２２の電気抵
抗変化の差を検出することにより、異方性磁気抵抗効果
を相殺することができ、対称性の良い再生波形が得られ
る。また、サーマルアスピリティーによるノイズを打ち
消すことができる。As described with reference to the magnetoresistive sensor of FIG.
In the magnetoresistive sensor of the present invention, among the layers of the first and second magnetic sensor films 21 and 22, the directions of the magnetizations of the ferromagnetic thin film layers 11 and 18 for fixing the magnetization are opposite to each other. By detecting the difference in electrical resistance change between the second magnetic sensor films 21 and 22, the anisotropic magnetoresistance effect can be canceled, and a reproduced waveform with good symmetry can be obtained. Further, noise due to thermal spirit can be canceled.

【００３６】なお、図５の磁気センサでは、一対の電極
３７が、第１の磁気センサ膜２１の上部の一部を両端か
ら覆うような形状にしている。同様に、一対の電極３９
は、第２の磁気センサ膜２２の上部の一部を両端から覆
う形状である。すなわち、図５の断面図は、電極３７、
３９を模式的に示しているが、実際には、図１３のよう
な形状であり、一対の電極３７は、一対の磁気センサ膜
２１の上部の両端部にかぶせられているため、一対の電
極３７の先端の間隔１３１は、一対の縦バイアス膜３６
の先端の間隔１３２よりも狭くなっている。同様に、一
対の電極３９の先端の間隔１３３は、一対の縦バイアス
膜３８の先端の間隔１３４よりも狭くなっている。In the magnetic sensor shown in FIG. 5, the pair of electrodes 37 are formed so as to cover a part of the upper part of the first magnetic sensor film 21 from both ends. Similarly, a pair of electrodes 39
Has a shape that covers a part of the upper part of the second magnetic sensor film 22 from both ends. That is, the sectional view of FIG.
Although FIG. 39 is schematically shown, it is actually shaped as shown in FIG. 13 and the pair of electrodes 37 is covered over both ends of the upper part of the pair of magnetic sensor films 21, so that the pair of electrodes 37 is formed. The interval 131 at the tip of the pair 37 is a pair of the vertical bias films 36.
Is narrower than the interval 132 at the tip of. Similarly, the interval 133 between the tips of the pair of electrodes 39 is smaller than the interval 134 between the tips of the pair of vertical bias films 38.

【００３７】このように、電極３７、３９の先端の間隔
を狭くしているのは、電極３７、３９から磁気センサ膜
２１、２２に流す電流を、強磁性薄膜層１３、１６の感
度の高い中心部の領域にのみ流すためである。強磁性薄
膜層１３、１６のうち、縦バイアス膜３６、３８に近い
領域は、媒体からの磁界によって磁化が回転しにくく、
感度が鈍い。よって、この領域を、電極３７、３９で覆
うことにより、中心部の感度の高い領域のみを検出でき
るため、磁気抵抗センサの感度を向上させることができ
る。The reason why the distance between the tips of the electrodes 37 and 39 is narrowed is that the current flowing from the electrodes 37 and 39 to the magnetic sensor films 21 and 22 is high in sensitivity of the ferromagnetic thin film layers 13 and 16. This is for flowing only to the central region. In the ferromagnetic thin film layers 13 and 16, the regions close to the longitudinal bias films 36 and 38 are hardly rotated by the magnetic field from the medium,
Sensitivity is low. Therefore, by covering this region with the electrodes 37 and 39, only the region with high sensitivity at the center can be detected, so that the sensitivity of the magnetoresistive sensor can be improved.

【００３８】なお、本実施の形態では、基板１０の材料
としてガラスまたはセラミックスを用いている。また、
磁気センサ膜２１、２２の強磁性薄膜層１１、１３、１
６、１８の材料としては、例えばＣｏ、Ｆｅ、Ｎｉ、あ
るいはこれらを主成分とする合金を用いることができ
る。具体的には、例えば、強磁性薄膜層１１、１３、１
６、１８を、Ｎｉ₉₁Ｆｅ₁₉、Ｃｏ₉₀Ｆｅ₁₀、Ｃｏのいず
れかまたはこれらの積層膜で形成することができる。そ
の好ましい厚さは１から１５ｎｍである。非磁性導電層
１２、１９の材料としては、Ｃｕ、Ａｇ、Ａｕあるいは
これらを主成分とする合金を用いることができる。具体
的には、例えば、Ｃｕで形成することができる。その好
ましい厚さは１から５ｎｍである。また、絶縁層１４の
材料としては、酸化アルミニウム、酸化シリコン、酸化
タンタルあるいはこれらの混合物を用いることができ
る。反強磁性薄膜層３１と、反強磁性薄膜層３５とで
は、交換結合磁界が消失する温度、いわゆるブロッキン
グ温度が異なる材料を用いることが望ましい。これによ
り、製造時の磁界中熱処理を容易に行うことが可能にな
るためである。具体的には、例えば、反強磁性薄膜層３
１をＮｉＯ、反強磁性薄膜層３５をＦｅ₅₀Ｍｎ₅₀、また
はこの逆の組み合わせで形成することができる。また、
保護膜３２、３４は、例えば、Ｔａで形成することがで
きる。下地膜３３は、例えば、Ｔａ，Ｚｒ，Ｈｆのいず
れかで形成することができる。縦バイアス印加層３６、
３８は、記録媒体からの磁界よりも保磁力の大きな硬質
磁性体、あるいは強磁性体と反強磁性体の積層体を用い
ることができるが、本実施の形態のように磁気センサ膜
２１、２２に２枚の反強磁性薄膜層３１、３５を用いて
いる場合には、硬質磁性体を用いることが望ましい。例
えば、ＣｏＰｔ合金またはＣｏＣｒＰｔ合金で形成する
ことができる。電極３７、３９は、例えば、Ａｕまたは
Ｔａで形成することができる。In this embodiment, glass or ceramic is used as the material of the substrate 10. Also,
The ferromagnetic thin film layers 11, 13, 1 of the magnetic sensor films 21, 22
As the materials 6 and 18, for example, Co, Fe, Ni, or an alloy containing these as main components can be used. Specifically, for example, the ferromagnetic thin film layers 11, 13, 1
6, ₁₈ can be formed of any one of Ni ₉₁ Fe ₁₉ , Co ₉₀ Fe ₁₀ , and Co, or a laminated film thereof. Its preferred thickness is from 1 to 15 nm. As a material of the nonmagnetic conductive layers 12 and 19, Cu, Ag, Au, or an alloy containing these as main components can be used. Specifically, for example, it can be formed of Cu. Its preferred thickness is 1 to 5 nm. In addition, as a material of the insulating layer 14, aluminum oxide, silicon oxide, tantalum oxide, or a mixture thereof can be used. It is preferable that the antiferromagnetic thin film layer 31 and the antiferromagnetic thin film layer 35 use materials having different temperatures at which the exchange coupling magnetic field disappears, that is, so-called blocking temperatures. This is because heat treatment in a magnetic field during manufacturing can be easily performed. Specifically, for example, the antiferromagnetic thin film layer 3
1 may be formed of NiO, and the antiferromagnetic thin film layer 35 may be formed of Fe ₅₀ Mn ₅₀ , or the reverse combination. Also,
The protective films 32 and 34 can be formed of, for example, Ta. The base film 33 can be formed of, for example, any of Ta, Zr, and Hf. Vertical bias applying layer 36,
The hard magnetic material 38 having a larger coercive force than the magnetic field from the recording medium or a laminate of a ferromagnetic material and an antiferromagnetic material can be used for the magnetic sensor films 21 and 22 as in the present embodiment. When two antiferromagnetic thin film layers 31 and 35 are used, it is desirable to use a hard magnetic material. For example, it can be formed of a CoPt alloy or a CoCrPt alloy. The electrodes 37 and 39 can be formed of, for example, Au or Ta.

【００３９】つぎに、図５の磁気抵抗センサの製造方法
について説明する。Next, a method of manufacturing the magnetoresistive sensor shown in FIG. 5 will be described.

【００４０】ガラス、セラミクスからなる非磁性基板１
０の上に、まず反強磁性薄膜層３１を形成し、第１の強
磁性薄膜層１１、第１の非磁性導電層１２、第２の強磁
性薄膜層１３を順次成膜した後、保護膜３２で被覆す
る。これらの膜から構成される第１の磁気センサ膜２１
をイオンミリング法により、図５および図１３のような
所定の形状にパターニングした後、縦バイアス印加層３
６を形成する。そして、イオンミリング法により、第１
の磁気センサ膜２１の上部に形成された縦バイアス印加
層３６を取り除くことにより、第１の磁気センサ膜２１
の両脇にのみ縦バイアス印加層３６を配置することがで
きる。この上に、電極３７の形成するための層を形成す
る。そしてこの層を、イオンミリングによりパターンニ
ングすることにより電極３７が形成される。このとき、
電極３７の先端の間隔１３１が、磁気センサ膜２１の
幅、すなわち縦バイアス印加層３６の間隔１３４より狭
くなるように、電極３７が磁気センサ膜２１の両端にか
ぶさるようパターニングする。これにより、図５および
図１３のような形状の電極３７が形成できる。Non-magnetic substrate 1 made of glass and ceramics
First, an antiferromagnetic thin film layer 31 is formed on the first ferromagnetic thin film layer 31, a first ferromagnetic thin film layer 11, a first nonmagnetic conductive layer 12, and a second ferromagnetic thin film layer 13 are sequentially formed. Cover with membrane 32. First magnetic sensor film 21 composed of these films
Is patterned into a predetermined shape as shown in FIGS. 5 and 13 by an ion milling method.
6 is formed. Then, by the ion milling method, the first
By removing the vertical bias applying layer 36 formed on the upper part of the magnetic sensor film 21, the first magnetic sensor film 21 is removed.
The vertical bias application layer 36 can be arranged only on both sides of the above. On this, a layer for forming the electrode 37 is formed. The electrode 37 is formed by patterning this layer by ion milling. At this time,
The electrode 37 is patterned so as to cover both ends of the magnetic sensor film 21 so that the distance 131 between the tips of the electrodes 37 is smaller than the width of the magnetic sensor film 21, that is, the distance 134 between the vertical bias applying layers 36. Thus, an electrode 37 having a shape as shown in FIGS. 5 and 13 can be formed.

【００４１】この上に、絶縁層１４を成膜し、さらにこ
の上に磁気センサ膜２２を形成する。第２の磁気センサ
膜２２は、まず下地膜３３を成膜し、その上に第３の強
磁性薄膜層１６、第２の非磁性導電層１９、第４の強磁
性薄膜層１８、反強磁性薄膜層３５、保護膜３４を成膜
する。そして、第１の磁気センサ膜２１と露光装置の合
わせ誤差範囲内で同じ位置に、第２の磁気センサ膜２２
を所定の形状にパターニングする。そして、第１の磁気
センサ膜２１のときと同様の手法で、第２の磁気センサ
膜２２の両側に縦バイアス印加層３８、電極３９を形成
する。An insulating layer 14 is formed thereon, and a magnetic sensor film 22 is further formed thereon. As the second magnetic sensor film 22, first, a base film 33 is formed, and a third ferromagnetic thin film layer 16, a second nonmagnetic conductive layer 19, a fourth ferromagnetic thin film layer 18, The magnetic thin film layer 35 and the protective film 34 are formed. Then, the second magnetic sensor film 22 is located at the same position within the alignment error range between the first magnetic sensor film 21 and the exposure apparatus.
Is patterned into a predetermined shape. Then, a vertical bias applying layer 38 and an electrode 39 are formed on both sides of the second magnetic sensor film 22 in the same manner as in the case of the first magnetic sensor film 21.

【００４２】なお、第２の強磁性薄膜層１３と第３の強
磁性薄膜層１６の磁化は、成膜時に磁界を印加すること
によって、トラック幅方向２９に誘導する。第１の強磁
性薄膜層１１と第４の強磁性薄膜層１８の磁化は、第２
及び第３の強磁性薄膜層１３、１６の磁化の方向とは直
交方向である素子高さ方向２８に沿って互いに逆向きに
向ける。そのため、図５の形状の素子が形成された後に
磁界中熱処理を行う。この磁界中熱処理は、反強磁性薄
膜層３１および反強磁性薄膜層３５の一方のブロッキン
グ温度をＴ₁、他方のブロッキング温度をＴ₂（Ｔ₁＞
Ｔ₂）とした場合に、まず、熱処理温度ＴをＴ＞Ｔ₁まで
温度を上げ、素子高さ方向に磁界を印加しながら熱処理
を行う。その後温度を下げ、Ｔ₁＞Ｔ＞Ｔ₂の温度で、印
加する磁界の向きを反転させることにより、図１のよう
な磁化配置にすることができる。The magnetizations of the second ferromagnetic thin film layer 13 and the third ferromagnetic thin film layer 16 are induced in the track width direction 29 by applying a magnetic field during film formation. The magnetization of the first ferromagnetic thin film layer 11 and the fourth ferromagnetic thin film layer 18 is
And the third ferromagnetic thin film layers 13 and 16 are directed in opposite directions along an element height direction 28 which is a direction orthogonal to the direction of magnetization. Therefore, heat treatment in a magnetic field is performed after the element having the shape shown in FIG. 5 is formed. In this heat treatment in a magnetic field, the blocking temperature of one of the antiferromagnetic thin film layer 31 and the antiferromagnetic thin film layer 35 is set to T ₁ , and the other blocking temperature is set to T ₂ (T ₁ > T ₁ ).
In the case of T ₂ ), first, the heat treatment temperature T is raised to T> T ₁ and heat treatment is performed while applying a magnetic field in the element height direction. Thereafter, by lowering the temperature and inverting the direction of the applied magnetic field at a temperature of T ₁ >T> T ₂ , the magnetization arrangement as shown in FIG. 1 can be obtained.

【００４３】なお、縦バイアス印加層３６、３８は必須
のものではなく、バルクハウゼンノイズが発生しなけれ
ば設けなくともよい。Note that the vertical bias application layers 36 and 38 are not essential, and need not be provided if Barkhausen noise does not occur.

【００４４】また、縦バイアス印加層３６、３８からの
縦バイアス磁界による感度の低下が問題にならない場合
には、電極３７、３９を磁気センサ膜２１、２２の両端
にかぶせず、電極３７、３９の先端の間隔１３１、１３
３を縦バイアス印加層３６、３９の間隔１３２、１３４
と同じにすることができる。When the sensitivity does not decrease due to the vertical bias magnetic field from the vertical bias applying layers 36 and 38, the electrodes 37 and 39 are not covered on both ends of the magnetic sensor films 21 and 22, and the electrodes 37 and 39 are not covered. Intervals 131, 13
3 is the interval 132, 134 between the vertical bias application layers 36, 39.
Can be the same as

【００４５】また、図１６のように、縦バイアス印加層
３６、３８の配向を制御するために縦バイアス印加層３
６、３８の下に下地膜１３５を配置することもできる。
下地層１３５の材料としては、Ｃｒ等を用いることがで
きる。As shown in FIG. 16, the vertical bias applying layers 3 and 3 are controlled to control the orientation of the vertical bias applying layers 36 and 38.
Underlayers 6 and 38 may be provided with a base film 135.
As a material of the underlayer 135, Cr or the like can be used.

【００４６】また、上述の実施の形態では、電極３７、
３９等のパターニングに、イオンミリリング法を用いた
が、この方法に限らずリフトオフ法等の他の方法を用い
ることももちろん可能である。In the above embodiment, the electrodes 37,
Although the ion milling method is used for patterning such as 39, other methods such as a lift-off method can be used without being limited to this method.

【００４７】つぎに、図６を用いて本実施の形態の別の
形態の磁気抵抗センサについて説明する。また、図６の
磁気抵抗センサの形状を具体的に示す断面図を、図１４
に示す。図６、図１４の磁気抵抗センサは、図５の磁気
抵抗センサと同様の構成であるが、図５の磁気抵抗セン
サの第４の強磁性薄膜層１８および反強磁性薄膜層３５
の２層を、硬質磁性薄膜４０で置き換えている。なお、
ここで硬質磁性薄膜とは、記録媒体から磁気抵抗センサ
に加わる磁界よりも保磁力が大きい磁性体からなる薄膜
をいう。硬質磁性薄膜４０の磁化の方向は、第１の強磁
性薄膜層１１とは逆向きに向かせる。この構成により、
第３の強磁性薄膜層１６は、非磁性導電層１９と硬質磁
性薄膜４０とともに第２の磁気センサ２２を構成する。Next, another embodiment of the magnetoresistive sensor of the present embodiment will be described with reference to FIG. FIG. 14 is a sectional view specifically showing the shape of the magnetoresistive sensor in FIG.
Shown in The magnetoresistive sensors of FIGS. 6 and 14 have the same configuration as the magnetoresistive sensor of FIG. 5, but the fourth ferromagnetic thin film layer 18 and the antiferromagnetic thin film layer 35 of the magnetoresistive sensor of FIG.
Are replaced by a hard magnetic thin film 40. In addition,
Here, the hard magnetic thin film refers to a thin film made of a magnetic material having a larger coercive force than a magnetic field applied from the recording medium to the magnetoresistive sensor. The direction of magnetization of the hard magnetic thin film 40 is opposite to the direction of the first ferromagnetic thin film layer 11. With this configuration,
The third ferromagnetic thin film layer 16 constitutes a second magnetic sensor 22 together with the nonmagnetic conductive layer 19 and the hard magnetic thin film 40.

【００４８】図６の磁気抵抗センサを製造する場合に
は、図５の磁気抵抗センサと同様に成膜およびパターニ
ングを行って図６の形状を作製した後、磁界中熱処理を
行う際に、素子高さ方向２８の磁界を印加しながら磁界
中熱処理を行い、第１の強磁性薄膜層１１の磁化を固定
する。その後、常温で、熱処理中の磁界の方向とは逆向
きの磁界を印加することにより、硬質磁性薄膜４０の磁
化を第１の強磁性薄膜層１１とは逆向きに着磁し、図１
のような磁化配置を作る。When the magnetoresistive sensor shown in FIG. 6 is manufactured, the film is formed and patterned in the same manner as the magnetoresistive sensor shown in FIG. 5 to form the shape shown in FIG. Heat treatment in a magnetic field is performed while applying a magnetic field in the height direction 28 to fix the magnetization of the first ferromagnetic thin film layer 11. Thereafter, by applying a magnetic field in a direction opposite to the direction of the magnetic field during the heat treatment at room temperature, the magnetization of the hard magnetic thin film 40 is magnetized in the direction opposite to that of the first ferromagnetic thin film layer 11, and FIG.
Make a magnetization arrangement like

【００４９】なお、図６で、縦バイアス印加層３６、３
８に硬質磁性体を用いる場合、硬質磁性薄膜４０と縦バ
イアス印加層３６、３８とで保磁力の大きく異なる硬質
磁性体を用いるようにする。また、縦バイアス印加層３
６、３８を、強磁性体と反強磁性体の積層体で構成して
もよい。このとき、縦バイアス印加層３６、３８に用い
る反強磁性材料と、反強磁性薄膜３１のブロッキング温
度が異なるように材料を選択する。In FIG. 6, the vertical bias application layers 36, 3
When a hard magnetic material is used for the hard magnetic material 8, a hard magnetic material having a large coercive force between the hard magnetic thin film 40 and the longitudinal bias applying layers 36 and 38 is used. The vertical bias application layer 3
6, 38 may be composed of a laminate of a ferromagnetic material and an antiferromagnetic material. At this time, the material is selected so that the antiferromagnetic material used for the vertical bias application layers 36 and 38 and the blocking temperature of the antiferromagnetic thin film 31 are different.

【００５０】なお、図６の構成では、図５の磁気抵抗セ
ンサの第４の強磁性薄膜層１８と反強磁性薄膜層３５の
２層を、１層の硬質磁性薄膜４０で置き換えているが、
図５の反強磁性薄膜層３５のかわりに、硬質磁性薄膜層
を用い、第４の強磁性薄膜層１８の磁化を硬質磁性薄膜
層の磁化との強磁性的な交換結合によって固定すること
もできる。この場合、硬質磁性薄膜層の保磁力以上の外
部磁界が作用しない限り、第４の強磁性薄膜層１８の磁
化を固定した状態に保つことができる。In the configuration of FIG. 6, two layers of the fourth ferromagnetic thin film layer 18 and the antiferromagnetic thin film layer 35 of the magnetoresistive sensor of FIG. 5 are replaced by one hard magnetic thin film 40. ,
A hard magnetic thin film layer may be used instead of the antiferromagnetic thin film layer 35 of FIG. 5, and the magnetization of the fourth ferromagnetic thin film layer 18 may be fixed by ferromagnetic exchange coupling with the magnetization of the hard magnetic thin film layer. it can. In this case, the magnetization of the fourth ferromagnetic thin film layer 18 can be kept fixed unless an external magnetic field greater than the coercive force of the hard magnetic thin film layer acts.

【００５１】つぎに、図４の構成に対応する磁気抵抗セ
ンサの具体的な構成について、図７を用いて説明する。
また、磁気抵抗センサの形状を表す断面図を図１５に示
す。Next, a specific configuration of the magnetoresistive sensor corresponding to the configuration of FIG. 4 will be described with reference to FIG.
FIG. 15 is a sectional view showing the shape of the magnetoresistive sensor.

【００５２】非磁性基板４１０の上には、順に、下地層
４３３、第１の強磁性薄膜層４１１、第１の非磁性導電
層４１２、第２の強磁性薄膜層４１３が積層されてい
る。これらの膜は、第１の磁気センサ膜４２１を構成す
る。第１の磁気センサ膜４２１の両側には、バルクハウ
ゼンノイズを抑制するために、第１の強磁性薄膜層４１
１に縦バイアス磁界を印加する一対の縦バイアス印加層
４３６が配置されている。一対の縦バイアス印加層４３
６の上には、第１の磁気センサ膜４２１に信号検出電流
を流すための一対の電極４３７が配置されている。On the non-magnetic substrate 410, an underlayer 433, a first ferromagnetic thin film layer 411, a first non-magnetic conductive layer 412, and a second ferromagnetic thin film layer 413 are sequentially stacked. These films constitute the first magnetic sensor film 421. On both sides of the first magnetic sensor film 421, the first ferromagnetic thin film layer 41 is provided to suppress Barkhausen noise.
A pair of vertical bias applying layers 436 for applying a vertical bias magnetic field are disposed on each of the pair. A pair of vertical bias applying layers 43
A pair of electrodes 437 for causing a signal detection current to flow through the first magnetic sensor film 421 is arranged on 6.

【００５３】これらの構成は、絶縁性反強磁性薄膜層４
１５で被覆され、この上に、第２の磁気センサ膜４２２
が積層されている。第２の磁気センサ膜４２２は、順に
積層された、第３の強磁性薄膜層４１６、スペーサ層４
１７、第４の強磁性薄膜層４１８、第２の非磁性導電層
４１９、第５の強磁性薄膜層４２０、保護膜４３４から
構成される。第２の磁気センサ膜４２２の両脇には、一
対の縦バイアス印加層４３８、一対の電極４３９が配置
されている。These structures are the same as those of the insulating antiferromagnetic thin film layer 4.
15 on which the second magnetic sensor film 422 is placed.
Are laminated. The second magnetic sensor film 422 is formed by sequentially stacking a third ferromagnetic thin film layer 416 and a spacer layer 4
17, a fourth ferromagnetic thin film layer 418, a second nonmagnetic conductive layer 419, a fifth ferromagnetic thin film layer 420, and a protective film 434. A pair of vertical bias applying layers 438 and a pair of electrodes 439 are arranged on both sides of the second magnetic sensor film 422.

【００５４】各強磁性薄膜層４１１、４１３、４１６、
４１８、４２０の磁化の向きは、図４の磁気抵抗センサ
と同様である。すなわち、第１の磁気センサ膜４２１の
第２の強磁性薄膜層４１３の磁化４２４、ならびに、第
２の磁気センサ膜４２２の第４の強磁性薄膜層４１８の
磁化４２６は、素子の高さ方向２８に平行で互いに逆向
きに固定されている。第２の強磁性薄膜層４１３の磁化
の固定は、絶縁性反強磁性薄膜層４１５との交換結合に
よって成されている。第４の強磁性薄膜層４１８の磁化
の固定は、スペーサ層４１７を介して第３の強磁性薄膜
層４１６と反強磁性的に結合することによって成されて
いる。第３の強磁性薄膜層４１６の磁化は、絶縁性反強
磁性薄膜層４１５との交換結合によって、第２の強磁性
薄膜層４１３と同じ向きに固定されている。Each of the ferromagnetic thin film layers 411, 413, 416,
The magnetization directions of 418 and 420 are the same as those of the magnetoresistive sensor of FIG. That is, the magnetization 424 of the second ferromagnetic thin film layer 413 of the first magnetic sensor film 421 and the magnetization 426 of the fourth ferromagnetic thin film layer 418 of the second magnetic sensor film 422 are determined in the height direction of the element. 28 and fixed in opposite directions. The magnetization of the second ferromagnetic thin film layer 413 is fixed by exchange coupling with the insulating antiferromagnetic thin film layer 415. The magnetization of the fourth ferromagnetic thin film layer 418 is fixed by antiferromagnetic coupling with the third ferromagnetic thin film layer 416 via the spacer layer 417. The magnetization of the third ferromagnetic thin film layer 416 is fixed in the same direction as the second ferromagnetic thin film layer 413 by exchange coupling with the insulating antiferromagnetic thin film layer 415.

【００５５】また、第１の磁気センサ膜４２１の第１の
強磁性薄膜層４１１の磁化４２３、ならびに、第２の磁
気センサ膜４２２の第５の強磁性薄膜層４２０の磁化４
２７は、記録媒体からの磁界を受けていない場合には、
トラック幅方向２９に平行で同じ向きであり、記録媒体
からの磁界を受けると、その磁界の向きに応じて回転す
る。The magnetization 423 of the first ferromagnetic thin film layer 411 of the first magnetic sensor film 421 and the magnetization 4 of the fifth ferromagnetic thin film layer 420 of the second magnetic sensor film 422
27, when not receiving the magnetic field from the recording medium,
It is parallel to the track width direction 29 and has the same direction. When receiving a magnetic field from the recording medium, it rotates according to the direction of the magnetic field.

【００５６】また、電極４３７、４３９に接続される回
路構成は、図５の電極３７、３９に接続される回路構成
と同じである。The circuit configuration connected to the electrodes 437 and 439 is the same as the circuit configuration connected to the electrodes 37 and 39 in FIG.

【００５７】このように、図７の磁気センサでは、第２
および第４の強磁性薄膜層４１３、４１８の磁化の向き
を互いに逆向き固定し、しかも、第１および第２の磁気
センサ膜４２１、４２２の電気抵抗変化の差を検出する
構成にすることにより、異方性磁気抵抗効果を相殺する
ことができ、対称性の良い再生波形が得られる。また、
サーマルアスピリティーによるノイズを打ち消すことが
できる。As described above, in the magnetic sensor shown in FIG.
And the fourth ferromagnetic thin film layers 413 and 418 are fixed in directions opposite to each other, and the difference between the electric resistance changes of the first and second magnetic sensor films 421 and 422 is detected. The anisotropic magnetoresistance effect can be canceled out, and a reproduced waveform with good symmetry can be obtained. Also,
The noise due to thermal spirit can be canceled.

【００５８】なお、図７の磁気センサでは、図５の磁気
センサと同様、電極４３７、４３９が、磁気センサ膜４
２１、４２２の両端から上部の一部を覆うような形状に
している（図１５）。これにより、電極４３７、４３９
から磁気センサ膜４２１、４２２に流す電流を、磁気セ
ンサ膜４２１、４２２の中心部の領域にのみ流すことが
できるため、磁気抵抗センサの感度を向上させることが
できる。In the magnetic sensor shown in FIG. 7, the electrodes 437 and 439 are formed on the magnetic sensor film 4 similarly to the magnetic sensor shown in FIG.
21 and 422 are formed so as to cover a part of the upper part from both ends (FIG. 15). Thereby, the electrodes 437, 439
Therefore, the current flowing through the magnetic sensor films 421 and 422 can be passed only to the central region of the magnetic sensor films 421 and 422, so that the sensitivity of the magnetoresistive sensor can be improved.

【００５９】絶縁性反強磁性層４１５は、例えば、Ｎｉ
ＯおよびＣｏＯのいずれか、またはこれらの積層体によ
り形成することができる。また、スペーサ層４１７は、
Ｒｕ、Ｃｒ、Ｒｈ、Ｉｒのいずれか、あるいはこれらの
合金によりから形成することができる。スペーサ層４１
７の厚さは、０.３から１.０ｎｍの範囲であることが望
ましい。また、強磁性薄膜層４１１、４１３、４１６、
４１８、４２０は、上述の強磁性薄膜層１１等と同じ材
料で、非磁性導電層４１２、４１９は、非磁性導電層１
２等と同じ材料で、縦バイアス印加層４３６、４３８
は、縦バイアス印加層３６等と同じ材料で、電極４３
７、４３９は、電極３７等と同じ材料で、下地膜４３３
は、下地膜３３と同じ材料で、それぞれ形成することが
できる。The insulating antiferromagnetic layer 415 is made of, for example, Ni
It can be formed of any of O and CoO, or a laminate thereof. In addition, the spacer layer 417
It can be formed of any of Ru, Cr, Rh, and Ir, or an alloy thereof. Spacer layer 41
The thickness of 7 is desirably in the range of 0.3 to 1.0 nm. Also, the ferromagnetic thin film layers 411, 413, 416,
418 and 420 are made of the same material as the above-mentioned ferromagnetic thin film layer 11 and the like, and the nonmagnetic conductive layers 412 and 419 are made of the nonmagnetic conductive layer 1
Vertical bias applying layers 436, 438
Is the same material as the vertical bias applying layer 36 and the like,
7, 439 are the same material as the electrode 37 and the like;
Can be formed of the same material as the base film 33, respectively.

【００６０】つぎに、図７の磁気抵抗センサの製造方法
について説明する。Next, a method of manufacturing the magnetoresistive sensor shown in FIG. 7 will be described.

【００６１】第１の磁気センサ膜４２１および第２の磁
気センサ膜４２２、縦バイアス印加層４３６、４３８お
よび電極４３７、４３９の成膜およびパターニングは、
図５の磁気抵抗センサと同様に行う。The film formation and patterning of the first magnetic sensor film 421 and the second magnetic sensor film 422, the vertical bias applying layers 436 and 438, and the electrodes 437 and 439 are performed as follows.
This is performed in the same manner as the magnetoresistive sensor shown in FIG.

【００６２】このとき、第１の強磁性薄膜層４１１と第
５の強磁性薄膜層４２０は、成膜時に磁界を印加するこ
とによって、磁化の方向をトラック幅方向２９に誘導す
る。At this time, the first ferromagnetic thin film layer 411 and the fifth ferromagnetic thin film layer 420 induce a magnetization direction in the track width direction 29 by applying a magnetic field during film formation.

【００６３】また、第３の強磁性薄膜層４１６と第４の
強磁性薄膜層４１８との反強磁性的な結合を利用して、
第４の強磁性薄膜層４１８の磁化と第２の強磁性薄膜層
４１３の磁化とを、素子の高さ方向２８に平行でかつ互
いに逆向きの方向に向かせるため、図７の磁気センサの
成膜およびパターニング等を行った後、磁界中熱処理を
行う。印加する磁界の向きは、第２の強磁性薄膜層４１
３の磁化を向けたい方向（図４参照）である。ただし、
第３の強磁性薄膜層４１６は、その磁化量（飽和磁束密
度と膜厚との積）が、第４の強磁性薄膜層４１８の磁化
量より大きくなるように形成しておく。この磁界中熱処
理により、第２の強磁性薄膜層４１３の磁化が印加した
磁界の方向を向き、絶縁性反強磁性層４１５の磁化との
交換結合によりこの方向に固定される。同時に、第３お
よび第４の強磁性薄膜層４１６、４１８のうち磁化量の
大きな第３の強磁性薄膜層４１６の磁化が、印加した磁
界の方向を向き、絶縁性反強磁性層４１５の磁化との交
換結合により固定される。このように、第３の強磁性薄
膜層４１６の磁化が固定されると、第４の強磁性薄膜層
４１８の磁化は、スペーサ層４１７を介した反強磁性的
な結合により、特に処理を施すことなく、第３の強磁性
薄膜層４１６の磁化とは逆向きに固定される。これによ
り、第４の強磁性薄膜層４１８の磁化と第２の強磁性薄
膜層４１３の磁化とを、素子の高さ方向２８に平行でか
つ互いに逆向きの方向に向かせることができる。Further, utilizing the antiferromagnetic coupling between the third ferromagnetic thin film layer 416 and the fourth ferromagnetic thin film layer 418,
In order to direct the magnetization of the fourth ferromagnetic thin film layer 418 and the magnetization of the second ferromagnetic thin film layer 413 in directions parallel to the height direction 28 of the element and in directions opposite to each other, the magnetic sensor of FIG. After performing film formation and patterning, heat treatment in a magnetic field is performed. The direction of the applied magnetic field is determined by the second ferromagnetic thin film layer 41.
3 is the direction in which the magnetization is desired to be directed (see FIG. 4). However,
The third ferromagnetic thin film layer 416 is formed so that the amount of magnetization (the product of the saturation magnetic flux density and the film thickness) is larger than the amount of magnetization of the fourth ferromagnetic thin film layer 418. By the heat treatment in the magnetic field, the magnetization of the second ferromagnetic thin film layer 413 faces the direction of the applied magnetic field, and is fixed in this direction by exchange coupling with the magnetization of the insulating antiferromagnetic layer 415. At the same time, the magnetization of the third ferromagnetic thin film layer 416 having a large magnetization amount among the third and fourth ferromagnetic thin film layers 416 and 418 is oriented in the direction of the applied magnetic field, and the magnetization of the insulating antiferromagnetic layer 415 is changed. Fixed by exchange coupling with As described above, when the magnetization of the third ferromagnetic thin film layer 416 is fixed, the magnetization of the fourth ferromagnetic thin film layer 418 is particularly subjected to processing by antiferromagnetic coupling via the spacer layer 417. Without being fixed, the magnetization of the third ferromagnetic thin film layer 416 is fixed in the opposite direction. Thereby, the magnetization of the fourth ferromagnetic thin film layer 418 and the magnetization of the second ferromagnetic thin film layer 413 can be directed in directions parallel to the height direction 28 of the element and opposite to each other.

【００６４】なお、この方法の他、磁界中成膜を利用し
て、第４の強磁性薄膜層４１８の磁化と第２の強磁性薄
膜層４１３の磁化とを、素子の高さ方向２８に平行でか
つ互いに逆向きの方向に向かせることもできる。この場
合、第２の強磁性薄膜層４１３および第３の強磁性薄膜
層４１６の成膜時に、素子高さ方向２８に平行で同じ向
きの磁界を印加しながら成膜する。そして、第３の強磁
性薄膜層４１６の上にスペーサ層４１７を成膜し、今度
は磁界を印加せずに、第４の強磁性薄膜層４１８を成膜
する。第４の強磁性薄膜層４１８の磁化は、第３の強磁
性薄膜層４１６との反強磁性的な結合によって、第３の
強磁性薄膜層４１６とは逆向きとなる。これによって、
第４の強磁性薄膜層４１８の磁化と第２の強磁性薄膜層
４１３の磁化とを、互いに逆向きに向かせることができ
る。この場合、第３の強磁性薄膜層４１６の磁化量が、
第４の強磁性薄膜層４１８の磁化量より大きくなるよう
に形成する必要はない。In addition to this method, the magnetization of the fourth ferromagnetic thin film layer 418 and the magnetization of the second ferromagnetic thin film layer 413 are changed in the height direction 28 of the element by utilizing film formation in a magnetic field. They can also be oriented in parallel and opposite directions. In this case, when the second ferromagnetic thin film layer 413 and the third ferromagnetic thin film layer 416 are formed, they are formed while applying a magnetic field parallel to the element height direction 28 and in the same direction. Then, a spacer layer 417 is formed on the third ferromagnetic thin film layer 416, and then a fourth ferromagnetic thin film layer 418 is formed without applying a magnetic field. The magnetization of the fourth ferromagnetic thin film layer 418 is opposite to that of the third ferromagnetic thin film layer 416 due to antiferromagnetic coupling with the third ferromagnetic thin film layer 416. by this,
The magnetization of the fourth ferromagnetic thin film layer 418 and the magnetization of the second ferromagnetic thin film layer 413 can be opposite to each other. In this case, the magnetization amount of the third ferromagnetic thin film layer 416 becomes
It is not necessary to form the fourth ferromagnetic thin film layer 418 so as to be larger than the magnetization amount.

【００６５】図７の磁気抵抗センサの構成では、反強磁
性薄膜層が絶縁性反強磁性薄膜層４１５の一層しか存在
しないので、比較的容易に、逆方向に磁化を固定するこ
とができる。また、縦バイアス印加層を設ける際にも、
硬質磁性体、および強磁性体と反強磁性体の積層体のど
ちらでも用いることができる。In the configuration of the magnetoresistive sensor shown in FIG. 7, since there is only one antiferromagnetic thin film layer of the insulating antiferromagnetic thin film layer 415, the magnetization can be fixed relatively easily in the opposite direction. Also, when providing a vertical bias applying layer,
Any of a hard magnetic material and a laminate of a ferromagnetic material and an antiferromagnetic material can be used.

【００６６】つぎに、上述の磁気抵抗センサを用いた磁
気抵抗効果ヘッドの実施の形態について説明する。Next, an embodiment of a magnetoresistive head using the above-described magnetoresistive sensor will be described.

【００６７】図８は、図６の磁気抵抗センサを用いた磁
気抵抗効果ヘッドの側面図である。通常の磁気抵抗効果
ヘッドでは、第１および第２の磁気センサ膜２１、２２
を記録媒体に近づけるために、ヘッドの記録媒体への対
向面５０に磁気センサ膜２１、２２の端面を露出する構
成を取る。しかしながら、図６の磁気抵抗センサのよう
に、強磁性薄膜層の代わりに硬質磁性薄膜４０を用いる
場合には、記録媒体からの信号磁界によって、硬質磁性
薄膜４０の素子の高さ方向２８に固定された磁化が減磁
され、磁化の方向が不安定になることがある。そこで、
本実施の形態では、図８のように、図６の磁気抵抗セン
サ１００を、ヘッドの記録媒体への対向面５０から遠ざ
ける。そして、磁気センサ膜２１、２２と、記録媒体へ
の対向面５０との間に軟磁性膜４１を配置し、記録媒体
からの信号磁界を軟磁性膜４１を通して磁気センサ素子
１００に導く。軟磁性膜４１は、透磁率の高い磁化困難
軸が素子の高さ方向２８と平行になるように形成する。FIG. 8 is a side view of a magnetoresistive head using the magnetoresistive sensor of FIG. In a normal magnetoresistive head, the first and second magnetic sensor films 21 and 22
In order to make the head closer to the recording medium, the end faces of the magnetic sensor films 21 and 22 are exposed on the surface 50 of the head facing the recording medium. However, when the hard magnetic thin film 40 is used instead of the ferromagnetic thin film layer as in the magnetoresistive sensor in FIG. 6, the hard magnetic thin film 40 is fixed in the height direction 28 of the element by the signal magnetic field from the recording medium. The applied magnetization may be demagnetized and the direction of the magnetization may become unstable. Therefore,
In the present embodiment, as shown in FIG. 8, the magnetoresistive sensor 100 of FIG. 6 is moved away from the surface 50 of the head facing the recording medium. Then, a soft magnetic film 41 is disposed between the magnetic sensor films 21 and 22 and the surface 50 facing the recording medium, and a signal magnetic field from the recording medium is guided to the magnetic sensor element 100 through the soft magnetic film 41. The soft magnetic film 41 is formed such that the hard axis having high magnetic permeability is parallel to the height direction 28 of the element.

【００６８】これにより、硬質磁性薄膜４０の磁化が減
磁されることを防止することができ、出力の減少および
不安定化を防ぐことができる。As a result, the magnetization of the hard magnetic thin film 40 can be prevented from being demagnetized, and the output can be prevented from decreasing and becoming unstable.

【００６９】なお、図６の磁気抵抗センサのかわりに、
強磁性薄膜層の磁化を固定するために硬質磁性薄膜を用
いる磁気抵抗センサや、図５や図７の磁気抵抗センサ
を、図８のヘッドに用いることももちろん可能である。Incidentally, instead of the magnetoresistive sensor of FIG. 6,
It is of course possible to use the magnetoresistive sensor using a hard magnetic thin film to fix the magnetization of the ferromagnetic thin film layer or the magnetoresistive sensor of FIGS. 5 and 7 for the head of FIG.

【００７０】また、図９は、上述してきた本実施の形態
の磁気抵抗センサを用いた磁気抵抗効果ヘッドの別の実
施の形態である。FIG. 9 shows another embodiment of a magnetoresistive head using the above-described magnetoresistive sensor of the present embodiment.

【００７１】これまでの実施の形態では、信号検出電流
をトラック幅方向２９に流すことを前提にしていたが、
図９のように、電極３９の一方を媒体との対向面５０に
配置し、縦長の形状にパターニングした磁気センサ膜２
２等の素子高さ方向に信号検出電流を流す構成にするこ
とができる。これにより、電極３９の間隔を、トラック
幅に制限されずに大きくすることができるため、磁気セ
ンサ膜の素子抵抗を大きくすることが可能である。これ
により、大きな出力を得ることができる。図９のヘッド
構成は、上述してきた本実施の形態の磁気抵抗センサの
いずれにも適用することができる。In the above embodiments, it is assumed that the signal detection current flows in the track width direction 29.
As shown in FIG. 9, one of the electrodes 39 is disposed on the surface 50 facing the medium, and the magnetic sensor film 2 is patterned into a vertically long shape.
A configuration in which the signal detection current flows in the height direction of the element such as 2 can be adopted. Thus, the interval between the electrodes 39 can be increased without being limited by the track width, and thus the element resistance of the magnetic sensor film can be increased. Thereby, a large output can be obtained. The head configuration of FIG. 9 can be applied to any of the above-described magnetoresistive sensors of the present embodiment.

【００７２】以上の実施の形態では、非磁性基板１０上
に直接磁気抵抗センサを形成した場合について説明した
が、高い分解能を得るために、第１及び第２の磁気セン
サ膜の上側または下側の少なくとも一方にギャップ層を
介してシ−ルド層を設けたり、また、記録用の誘導型磁
気素子を本発明の磁気抵抗センサの上側あるいは下側に
設けることももちろん可能である。このようにしても、
本発明の磁気抵抗センサの基本的な特性は変わるもので
はない。In the above embodiment, the case where the magnetoresistive sensor is formed directly on the non-magnetic substrate 10 has been described. However, in order to obtain high resolution, the upper or lower side of the first and second magnetic sensor films is required. It is of course possible to provide a shield layer via a gap layer on at least one of them, or to provide an inductive magnetic element for recording above or below the magnetoresistive sensor of the present invention. Even if you do this,
The basic characteristics of the magnetoresistive sensor of the present invention do not change.

【００７３】また、上述の各実施の形態の磁気抵抗セン
サは、図８、図９の形状の磁気抵抗効果ヘッドに用いる
以外に、磁気抵抗センサが媒体対向面に露出される一般
的な構造の磁気抵抗効果ヘッドにも用いることができ
る。The magnetoresistive sensor of each of the above-described embodiments has a general structure in which the magnetoresistive sensor is exposed to the medium facing surface, in addition to being used for the magnetoresistive heads having the shapes shown in FIGS. It can also be used for a magnetoresistive head.

【００７４】[0074]

【発明の効果】上述してきたように、本発明によれば、
巨大磁気抵抗効果を用いた磁気抵抗センサであって、異
方性磁気抵抗効果の影響を取り除き、対称性の良い再生
波形が安定して得られる磁気抵抗センサを提供すること
ができる。As described above, according to the present invention,
It is possible to provide a magnetoresistive sensor using a giant magnetoresistive effect, in which the influence of the anisotropic magnetoresistive effect is removed and a reproduced waveform with good symmetry is stably obtained.

[Brief description of the drawings]

【図１】本発明の磁気抵抗センサの一実施の形態の基本
的な層構成を示すための説明図。FIG. 1 is an explanatory diagram showing a basic layer configuration of an embodiment of a magnetoresistive sensor of the present invention.

【図２】（ａ），（ｂ）図１の構成の磁気抵抗センサの
２つの磁気センサ膜の各々の磁気抵抗変化曲線をシミュ
レーションにより求めた結果を示すグラフ。2 (a) and 2 (b) are graphs showing results obtained by simulating magnetoresistive change curves of two magnetic sensor films of the magnetoresistive sensor having the configuration of FIG.

【図３】図１の構成の磁気抵抗センサの２つの磁気セン
サ膜の電気抵抗変化の差を、磁気抵抗センサの出力とし
たときに得られる磁気抵抗変化曲線を示すグラフ。3 is a graph showing a magnetoresistive change curve obtained when a difference between electric resistance changes of two magnetic sensor films of the magnetoresistive sensor having the configuration of FIG. 1 is used as an output of the magnetoresistive sensor.

【図４】本発明の磁気抵抗センサの他の実施の形態の基
本的な層構成を示すための説明図。FIG. 4 is an explanatory diagram showing a basic layer configuration of another embodiment of the magnetoresistive sensor of the present invention.

【図５】本発明の磁気抵抗センサの具体的な構成の一実
施の形態を示すための断面図。FIG. 5 is a sectional view showing an embodiment of a specific configuration of the magnetoresistive sensor of the present invention.

【図６】本発明の磁気抵抗センサの具体的な構成の一実
施の形態を示すための断面。FIG. 6 is a cross-sectional view showing one embodiment of a specific configuration of the magnetoresistive sensor of the present invention.

【図７】本発明の磁気抵抗センサの具体的な構成の一実
施の形態を示すための断面。FIG. 7 is a cross-sectional view showing one embodiment of a specific configuration of the magnetoresistive sensor of the present invention.

【図８】本発明の磁気抵抗センサを用いた磁気抵抗効果
ヘッドの一実施の形態を示すための斜視図。FIG. 8 is a perspective view showing an embodiment of a magnetoresistive head using the magnetoresistive sensor of the present invention.

【図９】本発明の磁気抵抗センサを用いた磁気抵抗効果
ヘッドの一実施の形態を示すための斜視図。FIG. 9 is a perspective view showing an embodiment of a magnetoresistive head using the magnetoresistive sensor of the present invention.

【図１０】従来のスピンバルブ構造を有する磁気抵抗セ
ンサの基本的な層構成を示す説明図。FIG. 10 is an explanatory diagram showing a basic layer configuration of a conventional magnetoresistive sensor having a spin valve structure.

【図１１】従来のスピンバルブ構造を有する磁気抵抗セ
ンサの磁気抵抗変化曲線の測定結果を示すグラフ。FIG. 11 is a graph showing a measurement result of a magnetoresistance change curve of a magnetoresistance sensor having a conventional spin valve structure.

【図１２】従来のスピンバルブ構造を有する磁気抵抗セ
ンサの磁気抵抗変化曲線をシミュレーションにより計算
した結果を示すグラフ。FIG. 12 is a graph showing a result of calculating a magnetoresistive change curve of a magnetoresistive sensor having a conventional spin valve structure by simulation.

【図１３】図５の磁気抵抗センサの各層の具体的な形状
を示すための断面図。FIG. 13 is a sectional view showing a specific shape of each layer of the magnetoresistive sensor of FIG. 5;

【図１４】図６の磁気抵抗センサの各層の具体的な形状
を示すための断面図。FIG. 14 is a sectional view showing a specific shape of each layer of the magnetoresistive sensor of FIG. 6;

【図１５】図７の磁気抵抗センサの各層の具体的な形状
を示すための断面図。FIG. 15 is a sectional view showing a specific shape of each layer of the magnetoresistive sensor of FIG. 7;

【図１６】図５の磁気抵抗センサに下地膜１３５を加え
た構成を示すための断面図。FIG. 16 is a sectional view showing a configuration in which a base film 135 is added to the magnetoresistive sensor of FIG. 5;

[Explanation of symbols]

１０…基板、１１、４１１…第１の強磁性薄膜層、１
２、４１２…第１の非磁性導電層、１３、４１３…第２
の強磁性薄膜層、１４…絶縁層、４１５…絶縁性反強磁
性薄膜層、１６、４１６…第３の強磁性薄膜層、４１７
…スペーサ層、１８、４１８…第４の強磁性薄膜層、１
９、４１９…第２の非磁性導電層、２０、４２０…第５
の強磁性薄膜層、２１、４２１…第１の磁気センサ膜、
２２、４２２…第２の磁気センサ膜、２３、４２３…第
１の強磁性薄膜層の磁化、２４、４２４…第２の強磁性
薄膜層の磁化、２５、４２５…第３の強磁性薄膜層の磁
化、２６、４２６…第４の強磁性薄膜層の磁化、２７、
４２７…第５の強磁性薄膜層の磁化、２８…素子高さ方
向、２９…トラック幅方向、３１、３５…反強磁性薄膜
層、３２、３４…保護膜、３３…下地膜、３６、３８、
４３６、４３８…縦バイアス印加層、３７、３９、４
３７、４３９…電極、４０…硬質磁性薄膜、４１…軟磁
性膜、５０…媒体対向面、１００…磁気抵抗センサ。Reference numeral 10: substrate, 11, 411: first ferromagnetic thin film layer, 1
2, 412... First nonmagnetic conductive layer, 13, 413.
, 14, insulating layer, 415, insulating antiferromagnetic thin film layer, 16, 416, third ferromagnetic thin film layer, 417
... spacer layer, 18, 418 ... fourth ferromagnetic thin film layer, 1
9, 419 ... second non-magnetic conductive layer, 20, 420 ... fifth
, A first magnetic sensor film,
22, 422: second magnetic sensor film, 23, 423: magnetization of first ferromagnetic thin film layer, 24, 424: magnetization of second ferromagnetic thin film layer, 25, 425: third ferromagnetic thin film layer , 26, 426... The fourth ferromagnetic thin film layer, 27,
427: magnetization of the fifth ferromagnetic thin film layer, 28: element height direction, 29: track width direction, 31, 35: antiferromagnetic thin film layer, 32, 34: protective film, 33: base film, 36, 38 ,
436, 438: vertical bias application layer, 37, 39, 4
37, 439: electrode, 40: hard magnetic thin film, 41: soft magnetic film, 50: medium facing surface, 100: magnetoresistive sensor.

Claims

[Claims]

A first magnetic sensor film and a second magnetic sensor film in which a change in electric resistance is caused by a magnetic field from a recording medium; and a first magnetic sensor film for detecting a change in electric resistance of the first magnetic sensor film. An electrode pair, a second electrode pair for detecting a change in electric resistance of the second magnetic sensor film, and an electric resistance change detected from the first electrode pair and detected from the second electrode pair. An electrical circuit for determining a difference from an electrical resistance change, wherein the first magnetic sensor film and the second magnetic sensor film each include a first magnetic sensor film whose magnetization rotates in response to a magnetic field from a recording medium.
A ferromagnetic layer, a second ferromagnetic layer having a fixed magnetization, and a nonmagnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer. The magnetization of the second ferromagnetic layer of the first magnetic sensor film is fixed in a direction different from the direction in which the magnetization of the second ferromagnetic layer of the second magnetic sensor film is fixed. A magnetoresistive sensor characterized in that:

2. The method according to claim 1, wherein the direction in which the magnetization of the second ferromagnetic layer of the first magnetic sensor film is fixed is the direction of the magnetization of the second ferromagnetic layer of the second magnetic sensor film. A direction opposite to the direction in which is fixed.

3. A first electrode pair according to claim 1, wherein the first and second electrode pairs have an interval between the electrode pairs to detect a change in electric resistance at a central portion of the first and second magnetic sensor films. A magnetoresistive sensor, wherein the width is smaller than the width of the magnetic sensor film in the gap direction.

4. The first and second electrode pairs according to claim 3, wherein the first and second electrode pairs are respectively disposed on both sides of the first and second magnetic sensor films, and a part of the first and second electrode pairs is disposed on the first and second magnetic sensor films. A magnetic sensor film formed so as to cover a part of the upper surface from both ends of the magnetic sensor film.

5. The first and second magnetic sensor films according to claim 1, wherein the first and second magnetic sensor films each have an antiferromagnetic layer arranged so as to be in contact with each of the second ferromagnetic layers. Wherein the magnetization of the ferromagnetic layer is fixed by exchange coupling with the antiferromagnetic layer.

6. A magnetoresistive sensor according to claim 5, wherein said first magnetic sensor film and said second magnetic sensor film are laminated with an insulating layer interposed therebetween.

7. The semiconductor device according to claim 1, wherein the second magnetic sensor film and the second magnetic sensor film are laminated with an insulating antiferromagnetic layer interposed therebetween, and the first magnetic sensor film is A second ferromagnetic layer of the first magnetic sensor film is disposed so as to be in contact with the insulating antiferromagnetic layer; and a second ferromagnetic layer of the second magnetic sensor film. A second non-magnetic layer and a third ferromagnetic layer, which are sequentially stacked on a surface opposite to the non-magnetic layer, wherein the second magnetic sensor film has the third strength. A magnetic layer is disposed so as to be in contact with the insulating antiferromagnetic layer; a magnetization of the second ferromagnetic layer of the first magnetic sensor film is fixed by exchange coupling with the insulating antiferromagnetic layer; The magnetization of the third ferromagnetic layer of the second magnetic sensor film is fixed by exchange coupling with the insulating antiferromagnetic layer, The magnetization of the second ferromagnetic layer of the sensor film is antiferromagnetically coupled to the magnetization of the third ferromagnetic layer via the second nonmagnetic layer, so that the first magnetic sensor film Wherein the magnetization of the second ferromagnetic layer is fixed in a direction opposite to that of the second ferromagnetic layer.

8. The first magnetic sensor film according to claim 1, wherein the second ferromagnetic layer of the second magnetic sensor film is made of a magnetic material having a larger coercive force than a magnetic field from a recording medium. An antiferromagnetic layer in contact with the second ferromagnetic layer of the first magnetic sensor film, wherein the magnetization of the second ferromagnetic layer of the second magnetic sensor film has its own coercive force Wherein the magnetization of the second ferromagnetic layer of the first magnetic sensor film is fixed by exchange coupling with the antiferromagnetic layer.

9. The second magnetic sensor film according to claim 1, wherein the second magnetic sensor film includes a fourth ferromagnetic layer having a larger coercive force than a magnetic field from a recording medium and a second strong magnetic layer of the second magnetic sensor film. The first magnetic sensor film includes an antiferromagnetic layer disposed to be in contact with the second ferromagnetic layer of the first magnetic sensor film; The magnetization of the second ferromagnetic layer of the magnetic sensor film is fixed by the coercive force of the fourth ferromagnetic layer, and the magnetization of the second ferromagnetic layer of the first magnetic sensor film is A magnetoresistive sensor fixed by exchange coupling with a ferromagnetic layer.

10. A first magnetic sensor film and a second magnetic sensor film whose electric resistance changes due to a magnetic field from a recording medium, and a first magnetic sensor film for detecting a change in electric resistance of the first magnetic sensor film. An electrode pair; a second electrode pair for detecting a change in electric resistance of the second magnetic sensor film;
And an electric circuit for calculating a difference between an electric resistance change detected from the electrode pair and an electric resistance change detected from the second electrode pair. The first magnetic sensor film and the second magnetic sensor film First, the magnetization rotates in response to the magnetic field from the recording medium.
A ferromagnetic layer, a second ferromagnetic layer having a fixed magnetization, and a nonmagnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer. The first and second electrode pairs are arranged such that the distance between the electrode pairs is equal to the distance between the magnetic sensor films in the direction of the distance in order to detect a change in electric resistance at the center of the first and second magnetic sensor films. A magnetoresistive sensor having a width smaller than a width.

11. A magnetic head using a magnetoresistive sensor, comprising: a first magnetic sensor film and a second magnetic sensor film, on a substrate, of which electric resistance changes due to a magnetic field from a recording medium; A first electrode pair for detecting a change in electric resistance of the magnetic sensor film, and a second electrode pair for detecting a change in electric resistance of the second magnetic sensor film; And the first and second surfaces
A magnetic film for guiding a magnetic field from a recording medium is disposed between the magnetic sensor film and the first and second electrode pairs. The first and second electrode pairs have a change in electrical resistance detected from the first electrode pair. An electric circuit for obtaining a difference from the change in electric resistance detected from the second pair of electrodes is connected, and the first magnetic sensor film and the second magnetic sensor film each have a magnetization in accordance with a magnetic field from the recording medium. Rotating first
A ferromagnetic layer, a second ferromagnetic layer having a fixed magnetization, and a nonmagnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer. The magnetization of the second ferromagnetic layer of the first magnetic sensor film is fixed in a direction different from the direction in which the magnetization of the second ferromagnetic layer of the second magnetic sensor film is fixed. A magnetic head, characterized in that: