JP2003179283A - Magnetic sensor - Google Patents
Magnetic sensorInfo
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- JP2003179283A JP2003179283A JP2001379026A JP2001379026A JP2003179283A JP 2003179283 A JP2003179283 A JP 2003179283A JP 2001379026 A JP2001379026 A JP 2001379026A JP 2001379026 A JP2001379026 A JP 2001379026A JP 2003179283 A JP2003179283 A JP 2003179283A
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- resistance
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- ferromagnetic
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、巨大磁気抵抗（Gi
ant Magnet Resistance：以下、ＧＭＲという）素子
を用いた磁気センサに関するものである。TECHNICAL FIELD The present invention relates to a giant magnetic resistance (Gi
ant Magnet Resistance: hereinafter referred to as GMR) relates to a magnetic sensor using an element.
【０００２】[0002]
【従来の技術】物質の電気抵抗率が外部磁界の印加によ
って変化する現象を磁気抵抗効果（ＭＲ効果）といい、
この効果を示す半導体や、磁性体で一般的にみられる。
例えばＦｅ，Ｎｉ，Ｃｏなどの遷移金属合金では電流の
方向が磁化の向きと平行な場合と垂直な場合とで異なる
異方性磁気抵抗（これをＡＭＲ（Anisotropic Magneto
-Resistance）という）を示す。電流の方向が磁化の向
きと平行な場合に示す抵抗を縦磁気抵抗ρｌといい、垂
直な場合に示す抵抗を横磁気抵抗ρｔという。このＡＭ
Ｒの抵抗変化率Δρは（ρｌ−ρｔ）／（ρｌ＋２ρ
ｔ）で定義され、室温で数％のオーダである。2. Description of the Related Art The phenomenon in which the electrical resistivity of a substance changes by the application of an external magnetic field is called the magnetoresistive effect (MR effect).
It is generally found in semiconductors and magnetic materials that exhibit this effect.
For example, in a transition metal alloy such as Fe, Ni, and Co, an anisotropic magnetoresistance that differs depending on whether the current direction is parallel to or perpendicular to the magnetization direction (this is called AMR (Anisotropic Magneto
-Resistance)). The resistance shown when the current direction is parallel to the magnetization direction is called the longitudinal magnetic resistance ρl, and the resistance shown when it is perpendicular is called the transverse magnetic resistance ρt. This AM
The resistance change rate Δρ of R is (ρl−ρt) / (ρl + 2ρ
It is defined in t) and is of the order of a few percent at room temperature.
【０００３】そして、強磁性体では、電気抵抗率が磁化
方向と電流方向とのなす角度をθとしたとき、cosθの
２乗で変化することが知られている。強磁性体では、抵
抗変化率は約３％程度のものであり、従来の磁気抵抗素
子は、この効果を利用したものである。It is known that in a ferromagnetic material, the electrical resistivity changes as the square of cos θ, where θ is the angle between the magnetization direction and the current direction. A ferromagnetic material has a resistance change rate of about 3%, and the conventional magnetoresistive element utilizes this effect.
【０００４】しかし、近年では、この磁気抵抗素子の異
方性磁気抵抗効果よりも、はるかに大きな巨大磁気抵抗
効果（ＧＭＲ効果）を備えた巨大磁気抵抗素子（以下、
ＧＭＲ素子という）が着目されている。However, in recent years, a giant magnetoresistive element having a giant magnetoresistive effect (GMR effect) far larger than the anisotropic magnetoresistive effect of this magnetoresistive element (hereinafter,
A GMR element) is drawing attention.
【０００５】ＧＭＲ素子の中で人工格子型ＧＭＲ素子は
Ｎｉ，Ｃｏ，Ｆｅや、これらの合金（ＣｏＦｅ合金、Ｎ
ｉＦｅ合金、ＣｏＮｉ合金等）等の強磁性体からなる強
磁性層と、Ｃｕ，Ｃｒ又はＡｇ等の非磁性体からなる非
磁性層から構成されている。すなわち、このＧＭＲ素子
は前記強磁性層と非磁性層とが交互に１０〜５０層程度
積層された積層構造を備えている。Among the GMR elements, the artificial lattice type GMR element includes Ni, Co, Fe and alloys thereof (CoFe alloy, N
(iFe alloy, CoNi alloy, etc.) and a non-magnetic layer made of a non-magnetic material such as Cu, Cr, or Ag. That is, this GMR element has a laminated structure in which the ferromagnetic layers and the nonmagnetic layers are alternately laminated in about 10 to 50 layers.
【０００６】図６は、ＧＭＲ素子の特性を示す図であ
る。このＧＭＲ素子は、隣接した磁性層間の磁化の相対
角度によってＧＭＲ効果が生じ、抵抗値は互いに磁化が
反平行配列の場合に最大、平行配列の場合に最小にな
る。なお、反平行とは２つの磁性層の磁化の向きが逆向
きの配列をいい、平行とは２つの磁性層の磁化の向きが
同じ配列をいう。FIG. 6 is a diagram showing the characteristics of the GMR element. In this GMR element, the GMR effect occurs due to the relative angle of magnetization between adjacent magnetic layers, and the resistance value is maximum when the magnetizations are antiparallel and minimum when the magnetizations are parallel. The anti-parallel means an array in which the magnetization directions of the two magnetic layers are opposite to each other, and the parallel means an array in which the magnetization directions of the two magnetic layers are the same.
【０００７】ところで、このＧＭＲ素子を利用して、Ｇ
ＭＲ素子をブリッジ構造（ブリッジ回路）に構成し、磁
場により変化する抵抗と変化しない抵抗（基準抵抗）と
を組合わせた磁気センサが公知である。By the way, using this GMR element, G
A magnetic sensor is known in which an MR element is configured in a bridge structure (bridge circuit) and a resistance that changes with a magnetic field and a resistance that does not change (reference resistance) are combined.
【０００８】図７は、前記人工格子タイプのＧＭＲ素子
を用いた磁気センサＧＳの電気回路図である。同図に示
すようにホイーストンブリッジ回路１００は各辺にＧＭ
Ｒ素子５０〜５３から構成されている。ＧＭＲ素子５
０，５２は電源端子Ｖccに接続され、ＧＭＲ素子５１，
５３は接地されている。そして、ＧＭＲ素子５０，５３
は磁界の変化に応じて抵抗が変化する可変抵抗とされ、
一方、ＧＭＲ素子５１，５２は磁界の変化には抵抗が変
化しないように構成された基準抵抗とされている。FIG. 7 is an electric circuit diagram of a magnetic sensor GS using the artificial lattice type GMR element. As shown in the figure, the Wheatstone bridge circuit 100 has a GM on each side.
It is composed of R elements 50 to 53. GMR element 5
0 and 52 are connected to the power supply terminal Vcc, and GMR elements 51 and
53 is grounded. Then, the GMR elements 50 and 53
Is a variable resistor whose resistance changes in response to changes in the magnetic field,
On the other hand, the GMR elements 51 and 52 are reference resistors configured so that their resistance does not change with changes in the magnetic field.
【０００９】又、ＧＭＲ素子５０，５１間の接続点ａは
抵抗器Ｒ１を介して差動増幅回路６０のアンプ６１の反
転入力端子に接続されている。又、ＧＭＲ素子５２，５
３間の接続点ｂは差動増幅回路６０のアンプ６１の非反
転入力端子に接続されている。The connection point a between the GMR elements 50 and 51 is connected to the inverting input terminal of the amplifier 61 of the differential amplifier circuit 60 via the resistor R1. Also, the GMR elements 52, 5
The connection point b between 3 is connected to the non-inverting input terminal of the amplifier 61 of the differential amplifier circuit 60.
【００１０】前記アンプ６１の出力端子は、抵抗器Ｒ２
を介して自己の反転入力端子に接続されている。ＧＭＲ
素子５０，５３に印加される外部磁界が変化すると、前
記接続点ａ，ｂの電位の平衡が崩れ、差動増幅回路６０
の出力端にはその電位差に基づいた電圧が発生するよう
にされている。The output terminal of the amplifier 61 is a resistor R2.
It is connected to its own inverting input terminal via. GMR
When the external magnetic field applied to the elements 50 and 53 changes, the potentials of the connection points a and b are unbalanced, and the differential amplifier circuit 60
A voltage based on the potential difference is generated at the output terminal of the.
【００１１】上記のように構成された磁気センサＧＳに
おいて、ＧＭＲ素子５１、５２を基準抵抗とするため
に、従来は以下の３つの方法が提案されている。
１） 可変抵抗となるＧＭＲ素子５０，５３と、基準抵
抗（ＧＭＲ素子５１，５２）をマルチチップとし、ＧＭ
Ｒ素子５０，５３を構成しているチップ７０と基準抵抗
を構成しているチップ８０とは磁気の影響を受けないよ
うに離間する。In the magnetic sensor GS configured as described above, the following three methods have been conventionally proposed in order to use the GMR elements 51 and 52 as reference resistances. 1) The GMR elements 50 and 53, which are variable resistors, and the reference resistors (GMR elements 51 and 52) are multi-chip, and GM
The chip 70 forming the R elements 50 and 53 and the chip 80 forming the reference resistance are separated from each other so as not to be influenced by magnetism.
【００１２】図８では、チップ７０とチップ８０とが互
いに離間して配置した状態を示している。なお、図８〜
図１０において、９０は磁気センサに磁場の変化を付与
する磁石等の被検出体を示し、各図において、被検出体
９０は、矢印方向に移動していることを示している。In FIG. 8, the chip 70 and the chip 80 are shown separated from each other. Note that FIG.
In FIG. 10, reference numeral 90 denotes an object to be detected such as a magnet that gives a magnetic field change to the magnetic sensor, and in each figure, the object 90 to be detected is moving in the direction of the arrow.
【００１３】２） ＧＭＲ素子５０，５３と、基準抵抗
（ＧＭＲ素子５１，５２）をマルチチップとし、１）と
は異なり、ＧＭＲ素子５０，５３とＧＭＲ素子５１，５
２とを近接配置する。そして、その代わりに基準抵抗と
なるＧＭＲ素子５１．５２に例えば２５０℃以上の熱処
理を施し、ＧＭＲ効果を喪失させたものとする。2) The GMR elements 50, 53 and the reference resistors (GMR elements 51, 52) are multichip, and unlike 1), the GMR elements 50, 53 and the GMR elements 51, 5 are different.
2 and 2 are arranged close to each other. Then, instead, the GMR element 51.52 serving as the reference resistance is heat-treated at, for example, 250 ° C. or higher to lose the GMR effect.
【００１４】３） 基準抵抗となるＧＭＲ素子５１，５
２に磁気シールドを施して、外部磁界の影響を排除す
る。3) GMR elements 51, 5 serving as reference resistors
2 is magnetically shielded to eliminate the influence of external magnetic fields.
【００１５】[0015]
【発明が解決しようとする課題】ところが、上記１）及
び２）のようにマルチチップの場合には、各チップをそ
れぞれ配置するスペースが必要となり、小型化が難しく
なる問題がある。３）の磁気シールドを施す場合には、
磁気シールド性能を保証することが重要となる。すなわ
ち、磁気シールドを施す場合、基準抵抗上面に磁界を妨
げるだけの層厚を有する磁性体を積層する必要がある。
そして、例えば磁性体としてＦｅを使用した際には、基
準抵抗の表面全体に保護層を形成し、同保護層上に磁気
シールド層を形成し、さらにその上に防湿のための保護
膜を形成する。従って、磁気シールド層を形成する場合
は、磁気シールド層を保証するためのさらなる保護対策
が必要となる問題があった。However, in the case of the multi-chip as described in 1) and 2) above, there is a problem in that a space for arranging each chip is required and miniaturization becomes difficult. When applying the magnetic shield of 3),
It is important to guarantee magnetic shield performance. That is, when the magnetic shield is applied, it is necessary to stack a magnetic body having a layer thickness that hinders the magnetic field on the upper surface of the reference resistor.
Then, for example, when Fe is used as the magnetic substance, a protective layer is formed on the entire surface of the reference resistor, a magnetic shield layer is formed on the protective layer, and a protective film for moisture prevention is further formed thereon. To do. Therefore, when forming the magnetic shield layer, there is a problem that further protection measures are required to guarantee the magnetic shield layer.
【００１６】本発明の目的は、上記のような問題点を解
消するためになされたものである。すなわち、本発明
は、ＧＭＲ素子を構成する層の材質と同じ材質を使用す
ることを前提とし、積層構造を変えることにより、巨大
磁気抵抗素子の抵抗変化率よりも低い抵抗変化率を有す
る基準抵抗とする。このことにより、本発明の目的は、
１チップ化を容易に行うことができるとともに、小型化
を達成でき、磁気シールド層や、磁気シールド層を保証
するための保護膜の必要がない磁気センサを提供するこ
とにある。The object of the present invention is to solve the above problems. That is, the present invention is premised on using the same material as the material of the layers forming the GMR element, and by changing the laminated structure, a reference resistance having a resistance change rate lower than that of the giant magnetoresistive element. And Therefore, the object of the present invention is to
It is an object to provide a magnetic sensor that can be easily made into one chip and can be downsized, and that does not require a magnetic shield layer or a protective film for guaranteeing the magnetic shield layer.
【００１７】[0017]
【課題を解決するための手段】請求項１に記載の発明
は、基板上に非磁性層と強磁性層とを交互に積層した構
造体にて巨大磁気抵抗素子を構成し、基板上に前記巨大
磁気抵抗素子と同材質の非磁性層と強磁性層とを交互に
積層した構造体にて基準抵抗を構成し、同巨大磁気抵抗
素子と基準抵抗とによってブリッジ回路を構成し、巨大
磁気抵抗素子の抵抗が変化したときの前記ブリッジ回路
の不平衡出力によって磁界の変化を検出する磁気センサ
において、前記基準抵抗における非磁性層と強磁性層の
各層分の層厚を、前記巨大磁気抵抗素子の非磁性層と強
磁性層の抵抗変化率よりも低くなる層厚とし、かつ、前
記基準抵抗における非磁性層と強磁性層の積層数を、巨
大磁気抵抗素子における非磁性層と強磁性層の積層数よ
りも少なく形成して前記基準抵抗を前記巨大磁気抵抗素
子に対して低い抵抗変化率を有するようにし、同基準抵
抗の抵抗値を巨大磁気抵抗素子の抵抗値と同じ値に構成
したことを特徴とする磁気センサを要旨とするものであ
る。According to a first aspect of the present invention, a giant magnetoresistive element is constituted by a structure in which a nonmagnetic layer and a ferromagnetic layer are alternately laminated on a substrate, and the giant magnetoresistive element is formed on the substrate. The reference resistance is configured by a structure in which non-magnetic layers and ferromagnetic layers of the same material as the giant magnetoresistive element are alternately laminated, and a bridge circuit is configured by the giant magnetoresistive element and the reference resistance. In a magnetic sensor for detecting a change in magnetic field due to an unbalanced output of the bridge circuit when the resistance of the element changes, the layer thickness of each layer of the nonmagnetic layer and the ferromagnetic layer in the reference resistance is set to the giant magnetoresistive element. Of the non-magnetic layer and the ferromagnetic layer, the layer thickness is lower than the resistance change rate of the non-magnetic layer and the ferromagnetic layer. Less than the number of layers A magnetic sensor characterized in that the reference resistance has a low rate of resistance change with respect to the giant magnetoresistive element, and the resistance value of the reference resistance is set to the same value as the resistance value of the giant magnetoresistive element. It is what
【００１８】請求項２の発明は、請求項１において、前
記基準抵抗における非磁性層と強磁性層の層厚を、前記
巨大磁気抵抗素子における非磁性層と強磁性層の層厚よ
りもそれぞれ厚くしたことを特徴とする。According to a second aspect of the present invention, in the first aspect, the layer thicknesses of the non-magnetic layer and the ferromagnetic layer in the reference resistor are respectively smaller than the layer thicknesses of the non-magnetic layer and the ferromagnetic layer in the giant magnetoresistive element. It is characterized by being thickened.
【００１９】請求項３の発明は、請求項１又は請求項２
において、前記巨大磁気抵抗素子の構造体を構成する各
層の層厚の合計値と、前記基準抵抗の構造体を構成する
各層の層厚の合計値とを同じにしたことを特徴とする。The invention according to claim 3 is claim 1 or claim 2.
In the above, the total value of the layer thicknesses of the layers forming the structure of the giant magnetoresistive element and the total value of the layer thicknesses of the layers forming the structure of the reference resistance are the same.
【００２０】請求項４の発明は、請求項１乃至請求項３
のうちいずれか１項において、前記巨大磁気抵抗素子及
び前記基準抵抗とからなる前記ブリッジ回路を１チップ
化したことを特徴とする。The invention of claim 4 is the first to third aspects of the invention.
In any one of the above items, the bridge circuit including the giant magnetoresistive element and the reference resistor is integrated into one chip.
【００２１】[0021]
【発明の実施の形態】以下、本発明を具体化した実施形
態を図１〜図５を参照して説明する。図１は巨大磁気抵
抗素子と基準抵抗の構造体の概念図である。図２は巨大
磁気抵抗素子と基準抵抗で使用している磁性層と非磁性
層の膜厚と、抵抗変化率との関係を示した効果図であ
る。図３は磁気センサの電気回路図である。図４は磁気
センサを示し、ＧＭＲ素子１２，１３及び基準抵抗１
４，１５を透過した全体概念図である。図５（ａ）は巨
大磁気抵抗素子の構造体の概念図、（ｂ）はその断面
図、（ｃ）は、ＧＭＲ素子１２，１３の拡大断面図であ
る。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 is a conceptual diagram of a structure of a giant magnetoresistive element and a reference resistance. FIG. 2 is an effect diagram showing the relationship between the resistance change rate and the film thickness of the magnetic layer and the non-magnetic layer used in the giant magnetoresistive element and the reference resistance. FIG. 3 is an electric circuit diagram of the magnetic sensor. FIG. 4 shows a magnetic sensor including GMR elements 12 and 13 and a reference resistor 1.
It is the whole conceptual diagram which penetrated 4 and 15. 5A is a conceptual diagram of the structure of the giant magnetoresistive element, FIG. 5B is a sectional view thereof, and FIG. 5C is an enlarged sectional view of the GMR elements 12 and 13.
【００２２】図４に示すように、磁気センサ１０は、基
板１１上にＧＭＲ素子１２，１３及び基準抵抗１４，１
５とを備えている。基板１１はシリコン基板からなる。
ＧＭＲ素子１２，１３において、基板１１上面にＮｉ，
Ｆｅ等の金属からなるバッファ層２０ａを備えている。
同バッファ層２０ａは層厚が５〜５０ｎｍとされてい
る。バッファ層２０ａ上には、非磁性層２１ａと、強磁
性層２２ａとがペアとなり、両層が交互に積層された構
造体が形成されている。前記非磁性層２１ａは非磁性材
であるＣｕからなり、層厚が２．２ｎｍとされている。
又、強磁性層２２ａは強磁性材であるＣｏＦｅ合金から
なり、層厚が同じく２．２ｎｍとされている。本実施形
態では、前記非磁性層２１ａと強磁性層２２ａは、その
抵抗変化率が図２に示すようにともに略２０％となる層
厚に形成されている。すなわち、１層分の層厚は、巨大
磁気抵抗効果（ＧＭＲ効果）が発揮する層厚とされてい
る。そして、非磁性層２１ａと強磁性層２２ａとは、積
層数を１０〜５０層程度に積層されている。As shown in FIG. 4, the magnetic sensor 10 includes a GMR element 12, 13 and a reference resistor 14, 1 on a substrate 11.
5 and. The substrate 11 is a silicon substrate.
In the GMR elements 12 and 13, Ni,
A buffer layer 20a made of a metal such as Fe is provided.
The buffer layer 20a has a layer thickness of 5 to 50 nm. On the buffer layer 20a, a structure in which the non-magnetic layer 21a and the ferromagnetic layer 22a are paired and both layers are alternately laminated is formed. The non-magnetic layer 21a is made of Cu, which is a non-magnetic material, and has a layer thickness of 2.2 nm.
The ferromagnetic layer 22a is made of a CoFe alloy, which is a ferromagnetic material, and has the same layer thickness of 2.2 nm. In the present embodiment, the nonmagnetic layer 21a and the ferromagnetic layer 22a are both formed with a layer thickness such that the rate of change in resistance thereof is approximately 20% as shown in FIG. That is, the layer thickness for one layer is the layer thickness at which the giant magnetoresistive effect (GMR effect) is exhibited. The non-magnetic layer 21a and the ferromagnetic layer 22a are laminated in the number of laminated layers of about 10 to 50.
【００２３】一方、基準抵抗１４，１５においては、基
板１１上面にＧＭＲ素子１２，１３と同様にＮｉ，Ｆｅ
等の金属からなるバッファ層２０ｂを備えている。同バ
ッファ層２０ｂは層厚が５〜５０ｎｍとされている。バ
ッファ層２０ｂ上には、非磁性層２１ｂと、強磁性層２
２ｂとがペアとなり、ペアとなった両層が交互に積層さ
れた構造体が形成されている。On the other hand, in the reference resistors 14 and 15, Ni and Fe are formed on the upper surface of the substrate 11 similarly to the GMR elements 12 and 13.
The buffer layer 20b is made of a metal such as. The buffer layer 20b has a layer thickness of 5 to 50 nm. The nonmagnetic layer 21b and the ferromagnetic layer 2 are formed on the buffer layer 20b.
2b and 2b are paired with each other to form a structure in which the paired layers are alternately laminated.
【００２４】前記非磁性層２１ｂは非磁性材であるＣｕ
からなり、層厚が４ｎｍとされている。又、強磁性層２
２ｂは強磁性材であるＣｏＦｅ合金からなり、層厚が同
じく４ｎｍとされている。The nonmagnetic layer 21b is made of Cu, which is a nonmagnetic material.
And has a layer thickness of 4 nm. Also, the ferromagnetic layer 2
2b is made of a CoFe alloy, which is a ferromagnetic material, and has a layer thickness of 4 nm.
【００２５】本実施形態では、前記非磁性層２１ｂと強
磁性層２２ｂは、その抵抗変化率が図２に示すようにと
もに略５％となる層厚に形成されている。すなわち、１
層分の層厚は、巨大磁気抵抗効果（ＧＭＲ効果）が発揮
しない層厚とされている。なお、巨大磁気抵抗効果（Ｇ
ＭＲ効果）が発揮しない層厚としては、Ｃｕ，ＣｏＦｅ
をそれぞれ４ｎｍ以上とすればよい。In the present embodiment, the nonmagnetic layer 21b and the ferromagnetic layer 22b are both formed to have a layer thickness such that the rate of change in resistance is about 5% as shown in FIG. Ie 1
The layer thickness of the layers is such that the giant magnetoresistive effect (GMR effect) is not exhibited. The giant magnetoresistive effect (G
The layer thickness that does not exhibit the MR effect) is Cu, CoFe
Should be 4 nm or more.
【００２６】そして、非磁性層２１ｂと強磁性層２２ｂ
とは、前記ＧＭＲ素子１２，１３の積層数より少なくし
ている。そして、全非磁性層２１ａと全強磁性層２２ａ
との層厚の合計値と、全非磁性層２１ｂと全強磁性層ｂ
との層厚の合計値とが同じになるように、基準抵抗１
４，１５の積層数が設定されている。Then, the non-magnetic layer 21b and the ferromagnetic layer 22b
Is smaller than the number of stacked GMR elements 12 and 13. Then, the all non-magnetic layer 21a and the all ferromagnetic layer 22a
And the total value of the layer thicknesses of the total non-magnetic layer 21b and the total ferromagnetic layer b.
So that the total layer thickness of
The number of stacked layers of 4 and 15 is set.
【００２７】ＧＭＲ素子１２，１３と基準抵抗１４，１
５とは、各層の材料が互いに同じものを使用し、かつ、
各層の層厚の合計値が同じとしているため、外部磁界が
印加されていない状態では互いに温度係数、及び抵抗値
が同じとされている。GMR elements 12, 13 and reference resistors 14, 1
5 means that the material of each layer is the same as each other, and
Since the total value of the layer thickness of each layer is the same, the temperature coefficient and the resistance value are the same when the external magnetic field is not applied.
【００２８】なお、非磁性層２１ａ，２１ｂを最上層に
した場合は、ＧＭＲ効果に寄与しない電子が表面付近を
流れる確率が増加し、抵抗変化率の低下を招くことか
ら、最上層は強磁性層２２ａ，２２ｂであるのが望まし
い。When the non-magnetic layers 21a and 21b are the uppermost layers, the probability that electrons that do not contribute to the GMR effect will flow near the surface will decrease the resistance change rate. Layers 22a and 22b are preferred.
【００２９】又、図５（ｂ）に示すように、最上層の強
磁性層２２ａ，２２ｂの上には、窒化シリコンからなる
保護層３０が形成されている。なお、図５（ｂ）では、
ＧＭＲ素子１２，１３の断面構造のみを示しているが、
基準抵抗１４，１５においても同様に保護層３０が形成
されている。Further, as shown in FIG. 5B, a protective layer 30 made of silicon nitride is formed on the uppermost ferromagnetic layers 22a and 22b. In addition, in FIG.
Although only the sectional structure of the GMR elements 12 and 13 is shown,
A protective layer 30 is similarly formed on the reference resistors 14 and 15.
【００３０】ＧＭＲ素子１２，１３と基準抵抗１４，１
５とはそれぞれ各層の層厚が異なるため、ＧＭＲ素子１
２，１３及び基準抵抗１４，１５とは個別の成膜工程に
よって形成している。なお、成膜工程は、公知のスパッ
タリング、低温プラズマＣＶＤや真空蒸着等の薄膜処理
技術によって行われる。GMR elements 12, 13 and reference resistors 14, 1
Since the layer thickness of each layer is different from that of GMR element 5,
2, 13 and the reference resistors 14 and 15 are formed by separate film forming processes. The film forming process is performed by a known thin film processing technique such as sputtering, low temperature plasma CVD, or vacuum evaporation.
【００３１】そして、ＧＭＲ素子１２，１３及び基準抵
抗１４，１５が形成された後、各々の最上層である強磁
性層２２ａ，２２ｂ上に保護層３０を形成することによ
り、１チップ化されている。After the GMR elements 12 and 13 and the reference resistors 14 and 15 are formed, a protective layer 30 is formed on the uppermost ferromagnetic layers 22a and 22b, respectively, to form one chip. There is.
【００３２】そして、各ＧＭＲ素子１２，１３及び基準
抵抗１４，１５には、図５（ａ）に示すようにそれぞれ
金属配線３１を介して電極３２，３３が電気的に接続さ
れている。Electrodes 32 and 33 are electrically connected to the GMR elements 12 and 13 and the reference resistors 14 and 15 via metal wirings 31 as shown in FIG. 5A.
【００３３】なお、図４で示すＧＭＲ素子１２，１３の
平面形状は、図５（ａ）で示すＧＭＲ素子１２，１３の
平面形状と異なるが、図４では配置方向のみを概念化し
たものである。The plane shape of the GMR elements 12 and 13 shown in FIG. 4 is different from the plane shape of the GMR elements 12 and 13 shown in FIG. 5A, but only the arrangement direction is conceptualized in FIG. .
【００３４】ＧＭＲ素子１２，１３及び基準抵抗１４，
１５は前記電極３２，３３を介して、図３に示すように
ホイーストンブリッジ回路２００を構成するように接続
されている。GMR elements 12 and 13 and reference resistance 14,
15 is connected via the electrodes 32 and 33 so as to form a Wheatstone bridge circuit 200 as shown in FIG.
【００３５】すなわち、ホイーストンブリッジ回路２０
０は各辺に配置したＧＭＲ素子１２，１３及び基準抵抗
１４，１５から構成されている。ＧＭＲ素子１２及び基
準抵抗１４は電源端子Ｖccに接続され、ＧＭＲ素子１
３，基準抵抗１５は接地されている。そして、ＧＭＲ素
子１２，１３は磁界の変化に応じて抵抗が変化する可変
抵抗とされ、一方、基準抵抗１４，１５は磁界の変化に
は抵抗が変化しないように、非磁性層２１ｂ及び強磁性
層２２ｂの層厚が前述した厚みとされている。That is, the Wheatstone bridge circuit 20
Reference numeral 0 is composed of GMR elements 12 and 13 and reference resistors 14 and 15 arranged on each side. The GMR element 12 and the reference resistor 14 are connected to the power supply terminal Vcc, and the GMR element 1
3. The reference resistor 15 is grounded. The GMR elements 12 and 13 are variable resistances whose resistances change according to changes in the magnetic field, while the reference resistances 14 and 15 are non-magnetic layers 21b and ferromagnetic layers so that the resistances do not change with changes in the magnetic field. The layer thickness of the layer 22b is the thickness described above.
【００３６】又、ＧＭＲ素子１２，基準抵抗１５間の接
続点ａ及びＧＭＲ素子１３，基準抵抗１４間の接続点ｂ
から後段への電気的接続は図７の従来技術で説明した電
気的接続と同様であるため、図７で使用した符号を付し
て説明する。Further, a connection point a between the GMR element 12 and the reference resistor 15 and a connection point b between the GMR element 13 and the reference resistor 14
Since the electrical connection from to the subsequent stage is the same as the electrical connection described in the prior art of FIG. 7, the reference numerals used in FIG.
【００３７】すなわち、接続点ａは抵抗器Ｒ１を介して
差動増幅回路６０のアンプ６１の反転入力端子に接続さ
れている。又、接続点ｂは差動増幅回路６０のアンプ６
１の非反転入力端子に接続されている。That is, the connection point a is connected to the inverting input terminal of the amplifier 61 of the differential amplifier circuit 60 via the resistor R1. The connection point b is the amplifier 6 of the differential amplifier circuit 60.
1 is connected to the non-inverting input terminal.
【００３８】前記アンプ６１の出力端子は、抵抗器Ｒ２
を介して自己の反転入力端子に接続されている（図７参
照）。さて、上記のように構成された磁気センサ１０の
作用を説明する。The output terminal of the amplifier 61 is a resistor R2.
It is connected to its own inverting input terminal through (see FIG. 7). Now, the operation of the magnetic sensor 10 configured as described above will be described.
【００３９】図４に示すように、例えば磁石がｍ１の位
置に位置した場合、すなわち、磁気センサ１０に外部磁
界の印加がない状態では、ＧＭＲ素子１２，１３及び基
準抵抗１４，１５の抵抗は、同じである。このため、図
３に示す接続点ａ，ｂの電位は、同じであり平衡状態の
ままである。As shown in FIG. 4, for example, when the magnet is located at the position m1, that is, when no external magnetic field is applied to the magnetic sensor 10, the resistances of the GMR elements 12 and 13 and the reference resistors 14 and 15 are: , Same. Therefore, the potentials at the connection points a and b shown in FIG. 3 are the same and remain in the equilibrium state.
【００４０】次に、磁石がｍ２の位置に位置した場合、
すなわち、磁気センサ１０に外部磁界が印加した状態で
は、ＧＭＲ素子１２，１３は、最大で略２０％変化す
る。一方、基準抵抗１４，１５は最大で略５％変化す
る。Next, when the magnet is located at the position m2,
That is, when the external magnetic field is applied to the magnetic sensor 10, the GMR elements 12 and 13 change by about 20% at the maximum. On the other hand, the reference resistors 14 and 15 change by about 5% at maximum.
【００４１】従って、図３に示す接続点ａ，ｂの電位の
平衡が崩れ、両接続点ａ，ｂ間の電位差が生ずる。この
接続点ａ，ｂ間の最大電位差を計算すると、下記のよう
になる。Therefore, the equilibrium of the potentials at the connection points a and b shown in FIG. 3 is lost, and a potential difference between the connection points a and b occurs. The maximum potential difference between the connection points a and b is calculated as follows.
【００４２】接続点ａの電位Ｖａ，及び接続点ｂの電位
Ｖｂは下記の式（１）及び（２）で表される。なお、Ｇ
ＭＲ素子１２，１３，基準抵抗１４，１５のそれぞれ抵
抗値をｒ１，ｒ２，ｒ３，ｒ４とする。The potential Va at the connection point a and the potential Vb at the connection point b are expressed by the following equations (1) and (2). In addition, G
The resistance values of the MR elements 12 and 13 and the reference resistors 14 and 15 are r1, r2, r3 and r4, respectively.
【００４３】
Ｖａ＝（ｒ４／（ｒ１＋ｒ４））Ｖcc …（１）
Ｖｂ＝（ｒ２／（ｒ２＋ｒ３））Ｖcc …（２）
ＧＭＲ素子１２，１３の抵抗値ｒ１，ｒ２は、最大で、
略２０％変化することから、便宜的にここではｒ１＝ｒ
２＝１．２ｒとする。なお、ｒは外部磁界が印加してい
ないときの抵抗値とする。Va = (r4 / (r1 + r4)) Vcc (1) Vb = (r2 / (r2 + r3)) Vcc (2) The resistance values r1 and r2 of the GMR elements 12 and 13 are maximum,
Since it changes by about 20%, r1 = r for convenience here.
2 = 1.2r. Note that r is a resistance value when an external magnetic field is not applied.
【００４４】又、基準抵抗１４，１５の抵抗値ｒ３，ｒ
４は最大で、略５％変化することから、便宜的にここで
は、ｒ３＝ｒ４＝１．０５ｒとする。これらの値を前記
（１）、（２）式に代入すると、
Ｖａ＝（１．０５ｒ／（１．２ｒ＋１．０５ｒ））Ｖcc
＝０．４７Ｖcc
一方、
Ｖｂ＝（１．２ｒ／（１．２ｒ＋１．０５ｒ））Ｖcc
＝０．５３Ｖcc
となる。Further, the resistance values r3, r of the reference resistors 14, 15
Since 4 is the maximum and changes by about 5%, for convenience sake, r3 = r4 = 1.05r is set here. Substituting these values into the equations (1) and (2), Va = (1.05r / (1.2r + 1.05r)) Vcc = 0.47Vcc, while Vb = (1.2r / (1.2r + 1) .05r)) Vcc = 0.53Vcc.
【００４５】このように、外部磁界が磁気センサ１０に
印加された場合、接続点ａ，ｂ間には、最大（０．５３
Ｖcc−０．４７Ｖcc）＝０．０６Ｖccの電位差が生ず
る。この電位差を差動増幅回路６０により増幅する。As described above, when the external magnetic field is applied to the magnetic sensor 10, the maximum (0.53) is generated between the connection points a and b.
Vcc-0.47Vcc) = 0.06Vcc. This potential difference is amplified by the differential amplifier circuit 60.
【００４６】次に、上記のように構成した磁気センサ１
０の特徴について説明する。
（１） 本実施形態の磁気センサ１０は、基板１１上に
非磁性層２１ａと強磁性層２２ａとを交互に積層した構
造体にてＧＭＲ素子１２，１３（巨大磁気抵抗素子）を
構成した。又、基板１１上にＧＭＲ素子１２，１３と同
材質の非磁性層２１ｂと強磁性層２２ｂとを交互に積層
した構造体にて基準抵抗１４，１５を構成した。Next, the magnetic sensor 1 configured as described above.
The characteristics of 0 will be described. (1) In the magnetic sensor 10 of the present embodiment, the GMR elements 12 and 13 (giant magnetoresistive elements) are configured by a structure in which the nonmagnetic layers 21a and the ferromagnetic layers 22a are alternately laminated on the substrate 11. Further, the reference resistors 14 and 15 are constituted by a structure in which the non-magnetic layers 21b and the ferromagnetic layers 22b made of the same material as the GMR elements 12 and 13 are alternately laminated on the substrate 11.
【００４７】さらに、基準抵抗１４，１５における非磁
性層２１ｂと強磁性層２２ｂの各層分の層厚を、ＧＭＲ
素子１２，１３の非磁性層２１ａと強磁性層２２ａの抵
抗変化率よりも低くなる層厚とした。加えて、基準抵抗
１４，１５における非磁性層２１ｂと強磁性層２２ｂの
積層数を、ＧＭＲ素子１２，１３における非磁性層２１
ａと強磁性層２２ａの積層数よりも少なくした。又、基
準抵抗１４，１５の抵抗値をＧＭＲ素子１２，１３の抵
抗値と同じ値に構成した。そして、これらの構成によ
り、基準抵抗１４，１５をＧＭＲ素子１２，１３に対し
て低い抵抗変化率を有するようにした。Further, the layer thicknesses of the non-magnetic layer 21b and the ferromagnetic layer 22b in the reference resistors 14 and 15 are set to GMR.
The layer thickness was set to be lower than the rate of change in resistance of the nonmagnetic layer 21a and the ferromagnetic layer 22a of the elements 12 and 13. In addition, the number of laminated layers of the non-magnetic layer 21b and the ferromagnetic layer 22b in the reference resistors 14 and 15 is set to the non-magnetic layer 21 in the GMR elements 12 and 13.
The number is smaller than the number of laminated layers of a and the ferromagnetic layer 22a. Further, the resistance values of the reference resistors 14 and 15 are configured to be the same as the resistance values of the GMR elements 12 and 13. With these configurations, the reference resistors 14 and 15 have a low rate of resistance change with respect to the GMR elements 12 and 13.
【００４８】上記のように構成することにより、基準抵
抗１４，１５はＧＭＲ素子１２，１３が備えているＧＭ
Ｒ効果を有しないようにすることが可能となる。この結
果、磁気センサ１０を１チップ化でき、小型化を容易に
実現できる。さらに、１チップ化する際に磁気シールド
を施す必要がない。従来は磁気シールド層を形成する場
合、磁気シールド層を保証する防湿のための保護膜をさ
らに形成する必要があった。しかし、本実施形態では、
そのような磁気シールド層を保証するための保護膜が必
要でなくなる効果がある。With the above configuration, the reference resistors 14 and 15 are the GMs provided in the GMR elements 12 and 13.
It becomes possible not to have the R effect. As a result, the magnetic sensor 10 can be integrated into one chip, and miniaturization can be easily realized. Further, there is no need to apply a magnetic shield when forming one chip. Conventionally, when forming a magnetic shield layer, it was necessary to further form a protective film for guaranteeing the magnetic shield layer for preventing moisture. However, in this embodiment,
There is an effect that a protective film for guaranteeing such a magnetic shield layer is not necessary.
【００４９】（２） 本実施形態の磁気センサ１０で
は、基準抵抗１４，１５における非磁性層２１ｂと強磁
性層２２ｂの層厚（＝４ｎｍ）を、ＧＭＲ素子１２，１
３における非磁性層２１ａと強磁性層２２ａの層厚（＝
２．２ｎｍ）よりもそれぞれ厚くした。(2) In the magnetic sensor 10 of this embodiment, the layer thickness (= 4 nm) of the non-magnetic layer 21b and the ferromagnetic layer 22b in the reference resistors 14 and 15 is set to the GMR elements 12 and 1.
The layer thickness of the non-magnetic layer 21a and the ferromagnetic layer 22a in (3) (=
2.2 nm).
【００５０】このことにより、図２に示すように、基準
抵抗１４，１５の抵抗変化率がＧＭＲ素子１２の抵抗変
化率よりも低くすることができる。又、本実施形態で
は、上記のような基準抵抗１４，１５を構成する各層の
層厚を選択したことにより、基準抵抗１４，１５はＧＭ
Ｒ素子１２，１３が備えているＧＭＲ効果を有しないも
のとなる。As a result, as shown in FIG. 2, the resistance change rate of the reference resistors 14 and 15 can be made lower than that of the GMR element 12. Further, in the present embodiment, the reference resistors 14 and 15 are GM by selecting the layer thickness of each layer constituting the reference resistors 14 and 15 as described above.
The R elements 12 and 13 do not have the GMR effect.
【００５１】（３） 本実施形態では、ＧＭＲ素子１
２，１３の構造体を構成する各層（非磁性層２１ａ，強
磁性層２２ａ）の層厚の合計値と、基準抵抗１４，１５
の構造体を構成する各層（非磁性層２１ｂ，強磁性層２
２ｂ）の層厚の合計値とを同じにした。(3) In this embodiment, the GMR element 1
The total value of the layer thicknesses of the respective layers (nonmagnetic layer 21a, ferromagnetic layer 22a) constituting the structures 2, 3 and the reference resistors 14, 15
Of the layers (nonmagnetic layer 21b, ferromagnetic layer 2)
The total value of the layer thickness of 2b) was made the same.
【００５２】この結果、外部磁界が印加されていない状
態では互いに温度係数、抵抗値を同じにできる。
（４） 本実施形態では、ＧＭＲ素子１２，１３及び基
準抵抗１４，１５とからなるホイーストンブリッジ回路
２００を１チップ化した。この結果、磁気センサ１０自
体を小型化できる。As a result, the temperature coefficient and the resistance value can be made the same when the external magnetic field is not applied. (4) In this embodiment, the Wheatstone bridge circuit 200 including the GMR elements 12 and 13 and the reference resistors 14 and 15 is integrated into one chip. As a result, the magnetic sensor 10 itself can be downsized.
【００５３】（５） 本実施形態では、ＧＭＲ素子１
２，１３の構造体を構成する非磁性層２１ａと強磁性層
２２ａの層厚を互いに抵抗変化率が同じとなる層厚
（２．２ｎｍ）とした。又、基準抵抗１４，１５の構造
体を構成する非磁性層２１ｂと強磁性層２２ｂの層厚を
互いに抵抗変化率が同じとなる層厚（４ｎｍ）とした。(5) In this embodiment, the GMR element 1
The layer thicknesses of the non-magnetic layer 21a and the ferromagnetic layer 22a constituting the structures 2 and 13 were set to the layer thicknesses (2.2 nm) at which the rate of resistance change was the same. Further, the layer thickness of the nonmagnetic layer 21b and the ferromagnetic layer 22b constituting the structure of the reference resistors 14 and 15 is set to the layer thickness (4 nm) at which the rate of resistance change is the same.
【００５４】この結果、外部磁界が印加された際のＧＭ
Ｒ素子１２，１３及び基準抵抗１４，１５の成膜工程に
おいて、層厚を管理するだけで、所定の抵抗変化率を備
えたＧＭＲ素子１２，１３及び基準抵抗１４，１５を得
ることができる。As a result, GM when an external magnetic field is applied
In the film forming process of the R elements 12 and 13 and the reference resistors 14 and 15, only by controlling the layer thickness, the GMR elements 12 and 13 and the reference resistors 14 and 15 having a predetermined resistance change rate can be obtained.
【００５５】なお、本発明の実施形態は上記実施形態に
限定されるものではなく、次のように変更してもよい。
○ 前記実施形態では、保護層３０として、窒化シリコ
ンからなる保護層３０を形成したが、酸化シリコン膜を
保護層としてもよい。The embodiment of the present invention is not limited to the above embodiment, but may be modified as follows. In the above embodiment, the protective layer 30 made of silicon nitride was formed as the protective layer 30, but a silicon oxide film may be used as the protective layer.
【００５６】○ 前記実施形態では、非磁性層２１ａ，
２１ｂにＣｕを使用し、強磁性層２２ａ，２２ｂにＣｏ
Ｆｅ合金を使用したがこの組合せに限定するものではな
い。例えば、強磁性層／非磁性層と表記すると、下記の
組合せでもよい。In the above embodiment, the nonmagnetic layer 21a,
Cu is used for 21b and Co is used for the ferromagnetic layers 22a and 22b.
Although Fe alloy was used, it is not limited to this combination. For example, the expression "ferromagnetic layer / nonmagnetic layer" may be the following combination.
【００５７】Ｃｏ／Ｃｕ，ＮｉＦｅ合金／Ｃｕ，ＮｉＦ
ｅ合金／Ａｇ，ＮｉＦｅＣｏ合金／Ｃｕ，Ｆｅ／Ｃｒ、
ＣｏＮｉ合金／Ｃｕ等を挙げることができる。○ 前記
実施形態では、ＧＭＲ素子１２，１３の強磁性層と、非
磁性層との層厚を互いに同一にしたが、同一にしなくて
もよい。Co / Cu, NiFe alloy / Cu, NiF
e alloy / Ag, NiFeCo alloy / Cu, Fe / Cr,
CoNi alloy / Cu etc. can be mentioned. In the above embodiment, the ferromagnetic layers of the GMR elements 12 and 13 and the non-magnetic layer have the same layer thickness, but they do not have to have the same layer thickness.
【００５８】○ 前記実施形態では、基準抵抗１４，１
５の強磁性層と非磁性層との層厚を互いに同一にした
が、同一にしなくてもよい。In the above embodiment, the reference resistors 14 and 1
Although the ferromagnetic layer and the nonmagnetic layer of No. 5 have the same layer thickness, they do not have to be the same.
【００５９】[0059]
【発明の効果】以上詳述したように、請求項１乃至請求
項４に記載の発明によれば、１チップ化を容易に行うこ
とができるとともに、小型化を達成でき、磁気シールド
層や、磁気シールド層を保証するための保護膜の必要が
ない効果を奏する。As described above in detail, according to the first to fourth aspects of the present invention, one chip can be easily formed, and downsizing can be achieved. The effect that there is no need for a protective film for guaranteeing the magnetic shield layer is obtained.
【図１】巨大磁気抵抗素子と基準抵抗の構造体の概念
図。FIG. 1 is a conceptual diagram of a structure of a giant magnetoresistive element and a reference resistance.
【図２】巨大磁気抵抗素子と基準抵抗で使用している磁
性層と非磁性層の層厚と、抵抗変化率との関係を示した
特性図。FIG. 2 is a characteristic diagram showing the relationship between the resistance change rate and the layer thicknesses of the magnetic layer and the non-magnetic layer used in the giant magnetoresistive element and the reference resistance.
【図３】磁気センサの電気回路図。FIG. 3 is an electric circuit diagram of a magnetic sensor.
【図４】磁気センサの全体概念図である。FIG. 4 is an overall conceptual diagram of a magnetic sensor.
【図５】（ａ）は巨大磁気抵抗素子の構造体の概念図、
（ｂ）はその断面図、（ｃ）は、ＧＭＲ素子１２，１３
の拡大断面図。5A is a conceptual diagram of a structure of a giant magnetoresistive element, FIG.
(B) is its sectional view, (c) shows GMR elements 12, 13
FIG.
【図６】ＧＭＲ素子の特性図。FIG. 6 is a characteristic diagram of a GMR element.
【図７】ＧＭＲ素子を用いた磁気センサの電気回路図。FIG. 7 is an electric circuit diagram of a magnetic sensor using a GMR element.
【図８】従来の磁気センサのマルチチップの配置を示す
概念図。FIG. 8 is a conceptual diagram showing a multi-chip arrangement of a conventional magnetic sensor.
【図９】従来の磁気センサのマルチチップの配置を示す
概念図。FIG. 9 is a conceptual diagram showing a multi-chip arrangement of a conventional magnetic sensor.
【図１０】従来の磁気センサの１チップの配置を示す概
念図。FIG. 10 is a conceptual diagram showing an arrangement of one chip of a conventional magnetic sensor.
１０…磁気センサ １１…基板 １２，１３…ＧＭＲ素子（巨大磁気抵抗素子） １４，１５…基準抵抗 ２１ａ，２１ｂ…非磁性層 ２２ａ，２２ｂ…強磁性層 ２００…ホイーストンブリッジ回路（ブリッジ回路） 10 ... Magnetic sensor 11 ... Substrate 12, 13 ... GMR element (giant magnetoresistive element) 14, 15 ... Reference resistance 21a, 21b ... Nonmagnetic layer 22a, 22b ... Ferromagnetic layer 200 ... Wheatstone bridge circuit (bridge circuit)
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 2G017 AA10 AD55 5E049 AA01 AA04 AA07 BA16 CB02 DB02 DB12 ─────────────────────────────────────────────────── ─── Continued front page F-term (reference) 2G017 AA10 AD55 5E049 AA01 AA04 AA07 BA16 CB02 DB02 DB12
Claims (4)
積層した構造体にて巨大磁気抵抗素子を構成し、基板上
に前記巨大磁気抵抗素子と同材質の非磁性層と強磁性層
とを交互に積層した構造体にて基準抵抗を構成し、同巨
大磁気抵抗素子と基準抵抗とによってブリッジ回路を構
成し、巨大磁気抵抗素子の抵抗が変化したときの前記ブ
リッジ回路の不平衡出力によって磁界の変化を検出する
磁気センサにおいて、 前記基準抵抗における非磁性層と強磁性層の各層分の層
厚を、前記巨大磁気抵抗素子の非磁性層と強磁性層の抵
抗変化率よりも低くなる層厚とし、かつ、前記基準抵抗
における非磁性層と強磁性層の積層数を、巨大磁気抵抗
素子における非磁性層と強磁性層の積層数よりも少なく
形成して前記基準抵抗を前記巨大磁気抵抗素子に対して
低い抵抗変化率を有するようにし、同基準抵抗の抵抗値
を巨大磁気抵抗素子の抵抗値と同じ値に構成したことを
特徴とする磁気センサ。1. A giant magnetoresistive element is constituted by a structure in which a nonmagnetic layer and a ferromagnetic layer are alternately laminated on a substrate, and a nonmagnetic layer and a strong material of the same material as the giant magnetoresistive element are formed on the substrate. A reference resistance is formed by a structure in which magnetic layers are alternately laminated, and a bridge circuit is formed by the giant magnetoresistive element and the reference resistance. When the resistance of the giant magnetoresistive element changes, In a magnetic sensor for detecting a change in magnetic field by a balanced output, the layer thickness of each layer of the non-magnetic layer and the ferromagnetic layer in the reference resistance is calculated from the resistance change rate of the non-magnetic layer and the ferromagnetic layer of the giant magnetoresistive element. And the reference resistance by forming the number of non-magnetic layers and ferromagnetic layers in the reference resistance smaller than the number of non-magnetic layers and ferromagnetic layers in the giant magnetoresistive element. Pair with the giant magnetoresistive element To have a low resistance change ratio Te, a magnetic sensor, characterized in that to constitute a resistance value of the reference resistor to the same value as the resistance value of the giant magnetoresistance device.
層の層厚を、前記巨大磁気抵抗素子における非磁性層と
強磁性層の層厚よりもそれぞれ厚くしたことを特徴とす
る請求項１に記載の磁気センサ。2. The layer thickness of the non-magnetic layer and the ferromagnetic layer in the reference resistance is made thicker than the layer thickness of the non-magnetic layer and the ferromagnetic layer in the giant magnetoresistive element, respectively. Magnetic sensor according to.
る各層の層厚の合計値と、前記基準抵抗の構造体を構成
する各層の層厚の合計値とを同じにしたことを特徴とす
る請求項１又は請求項２に記載の磁気センサ。3. The total value of the layer thicknesses of the layers forming the structure of the giant magnetoresistive element and the total value of the layer thicknesses of the layers forming the structure of the reference resistance are the same. The magnetic sensor according to claim 1 or 2.
とからなる前記ブリッジ回路を１チップ化したことを特
徴とする請求項１乃至請求項３のうちいずれか１項に記
載の磁気センサ。4. The magnetic sensor according to claim 1, wherein the bridge circuit composed of the giant magnetoresistive element and the reference resistor is integrated into one chip.
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| JP2001379026A JP2003179283A (en) | 2001-12-12 | 2001-12-12 | Magnetic sensor |
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| JP2003179283A true JP2003179283A (en) | 2003-06-27 |
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| WO2006057379A1 (en) * | 2004-11-29 | 2006-06-01 | Alps Electric Co., Ltd. | Thin film magnetic resistor element and method for manufacturing it, and magnetic sensor using thin film magnetic resistor element |
| WO2007072774A1 (en) * | 2005-12-19 | 2007-06-28 | Ihi Corporation | Corrosion evaluation device, and corrosion evaluation method |
| JP2007248054A (en) * | 2006-03-13 | 2007-09-27 | Alps Electric Co Ltd | Magnetic sensor |
| JP2007271322A (en) * | 2006-03-30 | 2007-10-18 | Alps Electric Co Ltd | Magnetic detector, and manufacturing method therefor |
| CN100368820C (en) * | 2004-11-10 | 2008-02-13 | 中国科学院物理研究所 | Spinning valve type digital magnetic field sensor and fabrication method thereof |
| JP2008516255A (en) * | 2004-10-12 | 2008-05-15 | アレグロ・マイクロシステムズ・インコーポレーテッド | Resistor having a predetermined temperature coefficient |
| CN100392421C (en) * | 2004-11-10 | 2008-06-04 | 中国科学院物理研究所 | Switch type magnetic field sensor for current overload protector |
| WO2009055151A1 (en) * | 2007-10-22 | 2009-04-30 | Allegro Microsystems, Inc. | Matching of gmr sensors in a bridge |
| JP2021504684A (en) * | 2017-11-29 | 2021-02-15 | アレグロ・マイクロシステムズ・エルエルシー | Magnetic field sensor that can identify error situations |
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| JP2007248054A (en) * | 2006-03-13 | 2007-09-27 | Alps Electric Co Ltd | Magnetic sensor |
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| US7795862B2 (en) | 2007-10-22 | 2010-09-14 | Allegro Microsystems, Inc. | Matching of GMR sensors in a bridge |
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