JP2003078187A - Magnetic sensor - Google Patents
Magnetic sensorInfo
- Publication number
- JP2003078187A JP2003078187A JP2001316084A JP2001316084A JP2003078187A JP 2003078187 A JP2003078187 A JP 2003078187A JP 2001316084 A JP2001316084 A JP 2001316084A JP 2001316084 A JP2001316084 A JP 2001316084A JP 2003078187 A JP2003078187 A JP 2003078187A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic field
- thin film
- magnetic
- field sensor
- sensor element
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000005291 magnetic effect Effects 0.000 title claims abstract description 252
- 239000010409 thin film Substances 0.000 claims abstract description 135
- 239000010408 film Substances 0.000 claims abstract description 9
- 239000004020 conductor Substances 0.000 claims description 14
- 230000005290 antiferromagnetic effect Effects 0.000 claims description 13
- 239000002885 antiferromagnetic material Substances 0.000 claims description 5
- 239000000696 magnetic material Substances 0.000 claims description 5
- 230000035945 sensitivity Effects 0.000 abstract description 3
- 239000000463 material Substances 0.000 description 14
- 230000000694 effects Effects 0.000 description 7
- 238000010586 diagram Methods 0.000 description 6
- 230000004907 flux Effects 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 239000011800 void material Substances 0.000 description 5
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- 101000777456 Mus musculus Disintegrin and metalloproteinase domain-containing protein 15 Proteins 0.000 description 1
- 229910001260 Pt alloy Inorganic materials 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 229910000889 permalloy Inorganic materials 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- 238000001771 vacuum deposition Methods 0.000 description 1
Landscapes
- Measuring Magnetic Variables (AREA)
- Hall/Mr Elements (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は，空間中の磁界を測定す
る磁界センサに関し，巨大磁気抵抗薄膜，例えばナノグ
ラニュラー巨大磁気抵抗効果薄膜を用いて，磁界の大き
さと方向を精密に測定するための磁界センサに関するも
のである．BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic field sensor for measuring a magnetic field in space, which is used for precisely measuring the magnitude and direction of a magnetic field by using a giant magnetoresistive thin film, for example, a nanogranular giant magnetoresistive thin film. It is related to magnetic field sensors.
【０００２】[0002]
【従来の技術】図１は，本発明者らが出願した特開平１
１−８７８０４号公報及び特開平１１−２７４５９９に
記載された磁界センサを示す．図中，巨大磁気抵抗薄膜
と書かれた部分は，１０ｋＯｅの磁界の印加に対して，
約１０％の電気抵抗変化を示す金属−絶縁体ナノグラニ
ュラー巨大磁気抵抗薄膜である．この例のように，巨大
磁気抵抗薄膜の場合には，一般の磁気抵抗効果材料に比
して印加磁界に対する電気抵抗値の変化幅は大である
が，前記の通り電気抵抗変化を起こさせるための印加磁
界は大きく，巨大磁気抵抗薄膜のみを単独で用いる場合
には，一般に磁界センサとして利用されるような１００
Ｏｅ以下の小さな磁界での電気抵抗値の変化は期待でき
ない．図１の構成は，それを補うものである．すなわ
ち，軟磁性薄膜は周辺の磁束を集める役割を担ってお
り，適切な軟磁性薄膜の寸法を選定することにより，原
理的には，軟磁性薄膜周辺の磁界の大小に拘わらず，巨
大磁気抵抗薄膜部分に対して軟磁性薄膜の飽和磁束密度
以内で，いかようにも大きな磁束密度を印加することが
可能である．また，図１の構成を電気抵抗の観点から見
ると，軟磁性薄膜間の電気抵抗値は，軟磁性薄膜部分と
巨大磁気抵抗薄膜部分の電気抵抗値の和になっている
が，巨大磁気抵抗薄膜の電気比抵抗の値は，軟磁性薄膜
のそれに比して１００倍以上大きいため，実質的に軟磁
性薄膜間の電気抵抗値は巨大磁気抵抗薄膜部分の値と等
しい．つまり，軟磁性薄膜間の電気抵抗値には，巨大磁
気抵抗薄膜の電気抵抗値変化が直接現れる．図２は，こ
のような図１の構成の電気抵抗変化の例を示すものであ
り，数Ｏｅの小さな磁界において約６％の電気抵抗値変
化を実現している．2. Description of the Related Art FIG. 1 is a patent application filed by the present inventors.
The magnetic field sensors described in JP-A-1-87804 and JP-A-11-274599 are shown. In the figure, the part written as a giant magnetoresistive thin film, when applied with a magnetic field of 10 kOe,
It is a metal-insulator nano-granular giant magnetoresistive thin film that exhibits about 10% change in electrical resistance. In the case of a giant magnetoresistive thin film as in this example, the change width of the electric resistance value with respect to the applied magnetic field is larger than that of a general magnetoresistive material. Applied magnetic field is large, and when only a giant magnetoresistive thin film is used alone, it is generally used as a magnetic field sensor.
No change in electrical resistance can be expected in small magnetic fields below Oe. The configuration in Fig. 1 supplements it. That is, the soft magnetic thin film plays a role of collecting magnetic flux in the surroundings, and by selecting an appropriate size of the soft magnetic thin film, in principle, regardless of the magnitude of the magnetic field around the soft magnetic thin film, the giant magnetic resistance is increased. It is possible to apply a large magnetic flux density to the thin film portion within the saturation magnetic flux density of the soft magnetic thin film. From the viewpoint of electric resistance in the configuration of FIG. 1, the electric resistance value between the soft magnetic thin films is the sum of the electric resistance values of the soft magnetic thin film portion and the giant magnetoresistive thin film portion. Since the electric resistivity of the thin film is 100 times larger than that of the soft magnetic thin film, the electric resistance between the soft magnetic thin films is practically equal to that of the giant magnetoresistive thin film. In other words, changes in the electric resistance of the giant magnetoresistive thin film directly appear in the electric resistance between the soft magnetic thin films. FIG. 2 shows an example of the electric resistance change of such a configuration of FIG. 1, and realizes an electric resistance value change of about 6% in a small magnetic field of several Oe.
【０００３】[0003]
【発明が解決しようとする課題】しかし，本発明が目的
とする，巨大磁気抵抗薄膜の電気抵抗測定値をもとにし
て，印加された磁界の絶対値及び方向を計測する磁界セ
ンサを実現する場合には，図１の構成では，大きな問題
があることが判明した．それは，巨大磁気抵抗薄膜の電
気抵抗変化が磁界の方向に依存せず，等方的な特性を有
することである．すなわち，図２に示されるように，図
１の構成では，磁界の正負の２つの方向に対して同じ電
気抵抗変化を示し，磁界の方向を特定することが出来な
い．図１の構成のままでは，磁界の大きさのみを検出す
るセンサとしては利用できるが，磁界の方向を特定する
必要のある，地磁気の方向を読み取る方位センサや，着
磁した磁性体の相対角度を読み取る角度センサなどには
用いることが出来ない．However, a magnetic field sensor for measuring the absolute value and direction of an applied magnetic field based on the measured electric resistance of a giant magnetoresistive thin film, which is the object of the present invention, is realized. In that case, the configuration of Fig. 1 was found to have a major problem. It is that the electric resistance change of the giant magnetoresistive thin film does not depend on the direction of the magnetic field and has isotropic characteristics. That is, as shown in FIG. 2, the configuration of FIG. 1 shows the same electric resistance change in two positive and negative directions of the magnetic field, and the direction of the magnetic field cannot be specified. With the configuration shown in Fig. 1, it can be used as a sensor that detects only the magnitude of the magnetic field, but it is necessary to specify the direction of the magnetic field. It cannot be used as an angle sensor for reading.
【０００４】[0004]
【課題を解決するための手段】本発明の特徴とするとこ
ろは，下記の点にある．第一発明は，所定の空隙長を有
する空隙によって２分割され，且つ当該空隙の両側に接
した所定の厚さ及び幅を有する軟磁性薄膜と当該空隙を
埋めるように形成された巨大磁気抵抗薄膜とからなる磁
界センサ素子と磁界発生源とからなり，当該磁界発生源
から生じた磁界を，バイアス磁界として当該磁界センサ
素子に印加することにより，外部磁界の大きさ及び極性
を同時に検出することを特徴とする磁界センサに関す
る．The features of the present invention are as follows. A first invention is a soft magnetic thin film, which is divided into two parts by a space having a predetermined space length and has a predetermined thickness and width on both sides of the space, and a giant magnetoresistive thin film formed so as to fill the space. And a magnetic field generation source, and by applying the magnetic field generated from the magnetic field generation source to the magnetic field sensor element as a bias magnetic field, it is possible to simultaneously detect the magnitude and polarity of the external magnetic field. A characteristic magnetic field sensor.
【０００５】第二発明は，磁界発生源が，軟磁性薄膜と
硬磁性薄膜からなる多層膜における当該硬磁性薄膜であ
り，当該硬磁性薄膜によって生じた磁界を，バイアス磁
界として磁界センサ素子に印加することを特徴とする第
一発明に記載の磁界センサに関する．According to a second aspect of the invention, the magnetic field generation source is the hard magnetic thin film in a multilayer film composed of a soft magnetic thin film and a hard magnetic thin film, and the magnetic field generated by the hard magnetic thin film is applied to the magnetic field sensor element as a bias magnetic field. The present invention relates to the magnetic field sensor according to the first invention.
【０００６】第三発明は，磁界発生源が，軟磁性薄膜と
反強磁性薄膜からなる多層膜における当該反強磁性薄膜
であり，当該反強磁性薄膜によって生じた磁界を，バイ
アス磁界として磁界センサ素子に印加することを特徴と
する第一発明に記載の磁界センサに関する．According to a third aspect of the invention, the magnetic field generation source is the antiferromagnetic thin film in a multilayer film composed of a soft magnetic thin film and an antiferromagnetic thin film, and the magnetic field generated by the antiferromagnetic thin film is used as a bias magnetic field. The magnetic field sensor according to the first invention is characterized in that it is applied to an element.
【０００７】第四発明は，磁界発生源が，磁気センサ素
子の外部に配置した硬磁性体又は反強磁性体であり，当
該硬磁性体又は当該反強磁性体によって生じた磁界を，
バイアス磁界として当該磁界センサ素子に印加すること
を特徴とする第一発明に記載の磁界センサに関する．According to a fourth aspect of the invention, the magnetic field generation source is a hard magnetic material or an antiferromagnetic material arranged outside the magnetic sensor element, and the magnetic field generated by the hard magnetic material or the antiferromagnetic material is
A magnetic field sensor according to the first invention, characterized in that a bias magnetic field is applied to the magnetic field sensor element.
【０００８】第五発明は，磁界発生源が，磁気センサ素
子の外部に配置した硬磁性薄膜又は反強磁性薄膜であ
り，当該硬磁性薄膜又は当該反強磁性薄膜によって生じ
た磁界を，バイアス磁界として当該磁界センサ素子に印
加することを特徴とする第一発明に記載の磁界センサに
関する．According to a fifth aspect of the present invention, the magnetic field generation source is a hard magnetic thin film or an antiferromagnetic thin film arranged outside the magnetic sensor element, and the magnetic field generated by the hard magnetic thin film or the antiferromagnetic thin film is bias magnetic field. The present invention relates to the magnetic field sensor according to the first invention, characterized in that the magnetic field sensor element is applied to the magnetic field sensor element.
【０００９】第六発明は，磁界発生源が，磁気センサ素
子に密着して若しくは近傍に配置した導電体又は導電体
からなるコイルであり，当該導電体又は当該導電体から
なるコイルに電流を流して生じた磁界を，バイアス磁界
として当該磁界センサ素子に印加することを特徴とする
第一発明に記載の磁界センサに関する．According to a sixth aspect of the invention, the magnetic field generation source is a conductor or a coil made of a conductor which is placed in close contact with or in the vicinity of the magnetic sensor element, and a current is passed through the conductor or the coil made of the conductor. The magnetic field sensor according to the first aspect of the present invention is characterized in that the magnetic field generated as a result is applied to the magnetic field sensor element as a bias magnetic field.
【００１０】第七発明は，磁界発生源が，磁気センサ素
子に密着して若しくは近傍に配置した導電薄膜又は導電
薄膜からなるコイルであり，当該導電薄膜又は当該導電
薄膜からなるコイルに電流を流して生じた磁界を，バイ
アス磁界として当該磁界センサ素子に印加することを特
徴とする第一発明にに記載の磁界センサに関する．In a seventh aspect of the invention, the magnetic field generation source is a conductive thin film or a coil made of a conductive thin film, which is placed in close contact with or in the vicinity of the magnetic sensor element, and a current is passed through the conductive thin film or the coil made of the conductive thin film. The magnetic field sensor according to the first aspect of the invention is characterized in that the magnetic field generated thereby is applied to the magnetic field sensor element as a bias magnetic field.
【００１１】第八発明は，５０℃以上５００℃以下の温
度で熱処理したことを特徴とする第一発明ないし第七発
明のいずれか１項に記載の磁界センサに関する．An eighth invention relates to the magnetic field sensor according to any one of the first to seventh inventions, which is characterized by being heat-treated at a temperature of 50 ° C or more and 500 ° C or less.
【００１２】[0012]
【作用】本発明の作用は下記の通りである．第一発明の
構成は，バイアス磁界を印可することによって，図４，
図６及び図８におけるように電気抵抗変化曲線における
磁界０の点を任意に移動させ，測定しようとする磁界の
正負の方向（極性）の違いにより，電気抵抗変化に正負
の違いを生じさせるものである．これによって，磁界の
方向の違いによって，センサ出力に違いが発生するの
で，磁界の向きの判定が可能になる．また，電気抵抗変
化曲線の最も変化の大きい磁界に相当するバイアス磁界
を印加することによって，バイアス磁界を印加しない場
合よりもセンサの感度を高めることが出来る．The operation of the present invention is as follows. The configuration of the first aspect of the invention is such that by applying a bias magnetic field as shown in FIG.
As shown in FIG. 6 and FIG. 8, the point of the magnetic field 0 in the electric resistance change curve is arbitrarily moved, and the difference in positive and negative directions (polarity) of the magnetic field to be measured causes a positive or negative difference in electric resistance change. Is. As a result, the sensor output varies depending on the direction of the magnetic field, which makes it possible to determine the direction of the magnetic field. Moreover, by applying a bias magnetic field corresponding to the magnetic field with the largest change in the electric resistance change curve, the sensitivity of the sensor can be increased more than when the bias magnetic field is not applied.
【００１３】第二，第三，第四，第五及び第六発明の構
成は，具体的なバイアス磁界印加方法を示すものであ
る．バイアス磁界の印可方法は，本発明の磁界センサが
用いられるデバイスの種類によって，第二，第三，第
四，第五及び第六発明の何れか，若しくはそれらを組み
合わせた最適な方法を用いる．第五及び第六発明のコイ
ルを用いる場合では，コイルに流す電流値を調整するこ
とによって，容易にバイアス磁界の大きさを制御でき
る．一方，センサ全体が小さく，コイルの形成が難しい
デバイスでは，第二，第三また第四発明によるバイアス
印加方法が好適である．The configurations of the second, third, fourth, fifth and sixth inventions show specific bias magnetic field applying methods. As a method for applying the bias magnetic field, any one of the second, third, fourth, fifth and sixth inventions or an optimum method combining them is used depending on the type of device in which the magnetic field sensor of the present invention is used. When the coils of the fifth and sixth inventions are used, the magnitude of the bias magnetic field can be easily controlled by adjusting the value of the current flowing in the coil. On the other hand, the bias application method according to the second, third or fourth invention is suitable for a device in which the entire sensor is small and a coil is difficult to form.
【００１４】薄膜デバイスでは，成膜状態において内部
ひずみや応力が残存している．このため，本来の性能が
発揮されなかったり，ノイズが大きくなるなどの問題が
生じる．そこで，成膜後に５０℃以上５００℃以下の温
度で熱処理することによって，内部ひずみや応力が除去
され，特性が改善する．しかし，温度が５０℃未満で
は，内部ひずみ又は応力は十分には除去されず，５００
℃よりも高い場合には，軟磁性薄膜又は巨大磁気抵抗薄
膜の特性が劣化するため適当でない．In the thin film device, internal strain and stress remain in the film forming state. Therefore, problems such as the original performance not being exhibited and noise becoming large occur. Therefore, by performing heat treatment at a temperature of 50 ° C or higher and 500 ° C or lower after film formation, internal strain and stress are removed and the characteristics are improved. However, if the temperature is less than 50 ° C, internal strain or stress is not sufficiently removed, and
If the temperature is higher than ° C, the characteristics of the soft magnetic thin film or giant magnetoresistive thin film will deteriorate, which is not suitable.
【００１５】[0015]
【実施例】以下，図面に基づき，本発明の実施形態につ
いて説明する．
〔実施例１〕第一実施形態
図３は，本発明の第一の実施形態の一例を示す．この図
及び以降の図では，理解を助けるため軟磁性薄膜の部分
を斜線，巨大磁気抵抗薄膜の部分を点々の印，及び硬磁
性薄膜を白抜き，として区別している．保磁力の大きな
硬磁性薄膜は，保磁力の小さな軟磁性薄膜とは異なる磁
気特性を有する磁性薄膜である．本実施例では，軟磁性
薄膜，巨大磁気抵抗薄膜及び硬磁性薄膜は，スパッタ法
を用いＡｒガス雰囲気中で作製し，作製後２００℃で２
時間熱処理を施した．Embodiments of the present invention will be described below with reference to the drawings. Example 1 First Embodiment FIG. 3 shows an example of the first embodiment of the present invention. In this figure and the following figures, the portions of the soft magnetic thin film are distinguished by diagonal lines, the portions of the giant magnetoresistive thin film are indicated by dots, and the hard magnetic thin film is outlined by a white line to facilitate understanding. A hard magnetic thin film with a large coercive force is a magnetic thin film that has different magnetic properties from a soft magnetic thin film with a small coercive force. In this embodiment, the soft magnetic thin film, the giant magnetoresistive thin film, and the hard magnetic thin film are formed in an Ar gas atmosphere by using the sputtering method, and the temperature is set at 200 ° C.
Heat treatment was performed for an hour.
【００１６】軟磁性薄膜の厚さｔ１は１μｍである．軟
磁性薄膜には，空隙長ｇで示した空隙が形成されてい
る．空隙長ｇの寸法はｇ＝１μｍである．空隙に接する
軟磁性薄膜の幅ｗの寸法はｗ＝１００μｍである．ここ
では，軟磁性薄膜は，１５ｋＧ以上の高い飽和磁束密度
と，０．５Ｏｅ以下の小さい保磁力を有するパーマロイ
を用いた．その他の材料を含めて，軟磁性薄膜の具体的
な材料及びその代表特性は表１に示す．軟磁性薄膜とし
ては，保磁力が５Ｏｅ下で，飽和磁束密度が３ｋＧ以上
であることが望ましい．The thickness t 1 of the soft magnetic thin film is 1 μm. The soft magnetic thin film has voids indicated by the void length g. The dimension of the void length g is g = 1 μm. The width w of the soft magnetic thin film in contact with the void is w = 100 μm. Here, as the soft magnetic thin film, permalloy having a high saturation magnetic flux density of 15 kG or more and a small coercive force of 0.5 Oe or less was used. Table 1 shows the specific materials and their typical characteristics of the soft magnetic thin film, including other materials. The soft magnetic thin film preferably has a coercive force of 5 Oe or less and a saturation magnetic flux density of 3 kG or more.
【００１７】[0017]
【表１】 [Table 1]
【００１８】巨大磁気抵抗薄膜の材質は，Ｃｏ３９Ｙ
１４Ｏ４７合金薄膜である．軟磁性薄膜の空隙を埋める
ように巨大磁気抵抗薄膜が形成されている．巨大磁気抵
抗薄膜としては，電気抵抗変化率が大きい材料が望まし
い．この材料を含め，巨大磁気抵抗薄膜として可能な材
料及びその代表特性は表２に示す．The material of the giant magnetoresistive thin film is Co 39 Y
14 O 47 alloy thin film. A giant magnetoresistive thin film is formed so as to fill the void of the soft magnetic thin film. For the giant magnetoresistive thin film, a material with a large rate of change in electrical resistance is desirable. Table 2 shows the materials that can be used as giant magnetoresistive thin films, including this material, and their typical characteristics.
【００１９】[0019]
【表２】 [Table 2]
【００２０】軟磁性薄膜の下層には，硬磁性薄膜が形成
されている．硬磁性薄膜は，保磁力の大きなＦｅ５０Ｐ
ｔ５０合金薄膜で，厚さｔ２は０．１μｍである．そし
て，保磁力の小さな軟磁性薄膜と磁気的に結合し，軟磁
性薄膜にバイアス磁界を印加する作用を有する．硬磁性
薄膜は，任意の一軸異方性磁界と大きな保磁力を有し，
その厚さ及び磁気特性を変えることによって，任意の大
きさのバイアス磁界を軟磁性薄膜に印加することが出来
る．本実施形態では，硬磁性薄膜は，軟磁性薄膜の下層
に配置したが，軟磁性薄膜の上層，または軟磁性薄膜の
上下層の中間に挟まれるように配置しても同様の効果が
得られる．さらに，軟磁性薄膜及び硬磁性薄膜をそれぞ
れ複数の層（２層以上）に分割し，交互に積層しても良
い．ここでの硬磁性薄膜の材料は，反強磁性薄膜又は反
強磁性体と置き換えることによっても同様の効果が得ら
れる．Ｆｅ−Ｐｔ合金薄膜を含め，硬磁性薄膜として可
能な材料を表３に示す．A hard magnetic thin film is formed under the soft magnetic thin film. The hard magnetic thin film has a large coercive force of Fe 50 P.
It is a t 50 alloy thin film and has a thickness t 2 of 0.1 μm. Then, it has a function of magnetically coupling with a soft magnetic thin film having a small coercive force and applying a bias magnetic field to the soft magnetic thin film. Hard magnetic thin film has arbitrary uniaxial anisotropic magnetic field and large coercive force,
By changing its thickness and magnetic properties, it is possible to apply a bias magnetic field of arbitrary magnitude to the soft magnetic thin film. In the present embodiment, the hard magnetic thin film is placed in the lower layer of the soft magnetic thin film, but the same effect can be obtained by placing it in the upper layer of the soft magnetic thin film or in the middle of the upper and lower layers of the soft magnetic thin film. ． Furthermore, the soft magnetic thin film and the hard magnetic thin film may be divided into a plurality of layers (two or more layers) and stacked alternately. The same effect can be obtained by replacing the material of the hard magnetic thin film here with an antiferromagnetic thin film or an antiferromagnetic material. Table 3 shows possible materials for hard magnetic thin films, including Fe-Pt alloy thin films.
【００２１】[0021]
【表３】 [Table 3]
【００２２】図４には，第一の実施形態の特性図の一例
を示す．ここに示す例では，約−３．５Ｏｅのバイアス
磁界を印加している．電気抵抗は，外部磁界の正負の変
化に対して非対称に変化し，外部磁界の正負の方向の判
定が可能である．FIG. 4 shows an example of the characteristic diagram of the first embodiment. In the example shown here, a bias magnetic field of approximately -3.5 Oe is applied. The electric resistance changes asymmetrically with respect to the positive and negative changes of the external magnetic field, and it is possible to judge the positive and negative directions of the external magnetic field.
【００２３】〔実施例２〕第二実施形態
図５における硬磁性薄膜は，バイアス磁界を印加するた
めの保磁力の大きな硬磁性薄膜である．軟磁性薄膜，巨
大磁気抵抗薄膜及び硬磁性薄膜の作製法は，第一の実施
形態と同様である．また，軟磁性薄膜及び巨大磁気抵抗
薄膜の材質，空隙長ｇ，幅ｗ，及び軟磁性薄膜の厚さｔ
１なども，第一の実施形態と同様である．硬磁性薄膜
は，Ｆｅ５０Ｐｔ５０合金薄膜で，厚さは１μｍであ
り，保磁力の小さな軟磁性薄膜にバイアス磁界を印加す
る作用を有する．硬磁性薄膜は，任意の一軸異方性磁界
と保磁力を有し，その厚さと磁気特性を変えることによ
って，任意のバイアス磁界を軟磁性薄膜に印可すること
が出来る．硬磁性薄膜として可能な材料は，表３に示す
硬磁性薄膜又は反強磁性薄膜を用いても同様の効果が得
られる．[Second Embodiment] Second Embodiment The hard magnetic thin film in FIG. 5 is a hard magnetic thin film having a large coercive force for applying a bias magnetic field. The method of manufacturing the soft magnetic thin film, the giant magnetoresistive thin film, and the hard magnetic thin film is the same as in the first embodiment. Also, the material of the soft magnetic thin film and the giant magnetoresistive thin film, the gap length g, the width w, and the thickness t of the soft magnetic thin film.
1 and the like are the same as in the first embodiment. The hard magnetic thin film is a Fe 50 Pt 50 alloy thin film, has a thickness of 1 μm, and has a function of applying a bias magnetic field to a soft magnetic thin film having a small coercive force. A hard magnetic thin film has an arbitrary uniaxial anisotropic magnetic field and coercive force, and an arbitrary bias magnetic field can be applied to the soft magnetic thin film by changing its thickness and magnetic properties. The same effect can be obtained by using the hard magnetic thin film or antiferromagnetic thin film shown in Table 3 as the material that can be used as the hard magnetic thin film.
【００２４】図６には第二の実施形態の特性図の一例を
示す．ここに示す例では，約−３．５Ｏｅのバイアス磁
界を印可している．電気抵抗は，外部磁界の正負の変化
に対して非対称に変化し，外部磁界の正負の方向の判定
が可能である．FIG. 6 shows an example of a characteristic diagram of the second embodiment. In the example shown here, a bias magnetic field of approximately -3.5 Oe is applied. The electric resistance changes asymmetrically with respect to the positive and negative changes of the external magnetic field, and it is possible to judge the positive and negative directions of the external magnetic field.
【００２５】本実施形態では，一対の硬磁性体を軟磁性
薄膜及び巨大磁気抵抗膜を挟みこむように，空隙に平行
に配置しているが，これとは直角を成す方向，すなわち
空隙と直角を成す方向に配置しても同じ効果が得られ
る．硬磁性薄膜は，軟磁性薄膜に接していても離れてい
てもよく，また一対のうちどちらか一つでもその効果が
得られる．つまりは，硬磁性薄膜の配置や，形状を変え
ることによって，バイアス磁界の大きさを任意に制御す
ることが出来るのである．In the present embodiment, the pair of hard magnetic materials are arranged in parallel with the air gap so as to sandwich the soft magnetic thin film and the giant magnetoresistive film, but the direction perpendicular to this is formed, that is, the air gap is perpendicular to the air gap. The same effect can be obtained by arranging in the direction of formation. The hard magnetic thin film may be in contact with or apart from the soft magnetic thin film, and the effect can be obtained by either one of the pair. In other words, the magnitude of the bias magnetic field can be controlled arbitrarily by changing the arrangement and shape of the hard magnetic thin film.
【００２６】〔実施例３〕第三実施形態
図７における軟磁性薄膜及び巨大磁気抵抗薄膜の作製法
は，第一実施形態と同様である．また，軟磁性薄膜及び
巨大磁気抵抗薄膜の材質，空隙長ｇ，幅ｗ，及び軟磁性
薄膜の厚さｔ１なども，第一の実施形態と同様である．
導電体は，線径２０μｍ及び巻き数２０回でコイルを形
成し，該コイルの導電体に任意の電流を流すことによ
り，軟磁性膜及び巨大磁気抵抗薄膜からなる磁界センサ
素子に所望のバイアス磁界を印加する．また，巻数の多
寡により，バイアス磁界を調整できることは当然で，必
要に応じて適宜選択する．Example 3 Third Embodiment The method of manufacturing the soft magnetic thin film and the giant magnetoresistive thin film in FIG. 7 is the same as that of the first embodiment. Further, the materials of the soft magnetic thin film and the giant magnetoresistive thin film, the gap length g, the width w, the thickness t 1 of the soft magnetic thin film, etc. are the same as those in the first embodiment.
The conductor is formed into a coil with a wire diameter of 20 μm and the number of turns is 20 and an arbitrary current is applied to the conductor of the coil, so that a desired bias magnetic field is applied to the magnetic field sensor element including the soft magnetic film and the giant magnetoresistive thin film. Is applied. In addition, it is natural that the bias magnetic field can be adjusted by the number of turns, and the bias magnetic field can be selected as needed.
【００２７】図８には第三の実施形態の特性図の一例を
示す．ここに示す例では，約＋４Ｏｅのバイアス磁界を
印可している．電気抵抗は，外部磁界の正負の変化に対
して非対称に変化し，外部磁界の正負の方向の判定が可
能である．FIG. 8 shows an example of a characteristic diagram of the third embodiment. In the example shown here, a bias magnetic field of approximately +4 Oe is applied. The electric resistance changes asymmetrically with respect to the positive and negative changes of the external magnetic field, and it is possible to judge the positive and negative directions of the external magnetic field.
【００２８】本実施形態では，導電体はコイルを形成し
ているが，磁界センサ素子に密着して又はその近傍に直
線状又は曲線状の導電体を配置することにより，当該磁
界センサ素子にバイアス磁界を印加することも出来る．
また，本実施形態では，導電体は線材で形成したが，該
導電体をスパッタ法又は真空蒸着法などにより薄膜材料
で形成してもその効果は同一である．In the present embodiment, the conductor forms a coil. However, by placing a linear or curved conductor close to or near the magnetic field sensor element, the magnetic field sensor element is biased. A magnetic field can be applied.
Further, in the present embodiment, the conductor is formed of a wire material, but the effect is the same even if the conductor is formed of a thin film material by a sputtering method or a vacuum deposition method.
【００２９】[0029]
【発明の効果】上記の通り，本発明によれば次のような
効果が得られる．従来技術では，磁界の正負の方向（極
性）に対して同じ大きさの電気抵抗変化を示し，磁界の
方向を特定することが出来なかった．本発明によれば，
所定のバイアス磁界を印加することによって，磁界の大
きさ及び極性を同時に検出することができ，上記の問題
が解決できる．本発明の磁界センサは，磁界の方向を特
定する必要のある，方位センサや角度センサなどに用い
ることができ，かつそれらセンサの高性能化も可能であ
り，次世代の高性能磁界センサとして工業的意義は非常
に大きい．As described above, according to the present invention, the following effects can be obtained. In the conventional technology, the electric resistance change of the same magnitude was shown in the positive and negative directions (polarity) of the magnetic field, and the direction of the magnetic field could not be specified. According to the invention,
By applying a predetermined bias magnetic field, the magnitude and polarity of the magnetic field can be detected simultaneously, and the above problems can be solved. INDUSTRIAL APPLICABILITY The magnetic field sensor of the present invention can be used as an azimuth sensor, an angle sensor, or the like that needs to specify the direction of a magnetic field, and can also have high performance in those sensors. The significance is very large.
【図１】 従来技術による薄膜磁界センサ．FIG. 1 is a thin film magnetic field sensor according to the related art.
【図２】 同上の磁界印可による電気抵抗値の変化．[Fig. 2] Change in electric resistance value due to application of magnetic field.
【図３】 本発明の第一の実施形態．FIG. 3 is a first embodiment of the present invention.
【図４】 本発明，第一の実施形態の磁界印可による電
気抵抗値の変化．FIG. 4 is a diagram showing changes in electric resistance value due to magnetic field application according to the first embodiment of the present invention.
【図５】 本発明の第二の実施形態．FIG. 5 is a second embodiment of the present invention.
【図６】 本発明，第二の実施形態の磁界印可による電
気抵抗値の変化．FIG. 6 is a diagram showing changes in electric resistance value due to magnetic field application according to the second embodiment of the present invention.
【図７】 本発明の第三の実施形態．FIG. 7 shows a third embodiment of the present invention.
【図８】 本発明，第三の実施形態の磁界印可による電
気抵抗値の変化．FIG. 8 is a diagram showing changes in electric resistance value due to magnetic field application according to the third embodiment of the present invention.
ｗ：軟磁性薄膜の幅． ｇ：軟磁性薄膜に形成された空隙長． ｔ１：軟磁性薄膜の厚さ． ｔ２：硬磁性薄膜（反強磁性薄膜）の厚さ．w: width of the soft magnetic thin film. g: length of void formed in the soft magnetic thin film. t 1 : Thickness of the soft magnetic thin film. t 2 : Thickness of hard magnetic thin film (antiferromagnetic thin film).
───────────────────────────────────────────────────── フロントページの続き (72)発明者 増本 健 宮城県仙台市青葉区上杉３丁目８番22号 Ｆターム(参考） 2G017 AA01 AA02 AA03 AC09 AD55 AD56 AD65 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Ken Masumoto 3-8-22 Uesugi, Aoba-ku, Sendai City, Miyagi Prefecture F-term (reference) 2G017 AA01 AA02 AA03 AC09 AD55 AD56 AD65
Claims (8)
され，且つ当該空隙の両側に接した所定の厚さ及び幅を
有する軟磁性薄膜と，当該空隙を埋めるように形成され
た巨大磁気抵抗薄膜とからなる磁界センサ素子，及び磁
界発生源とからなり，当該磁界発生源から生じた磁界
を，バイアス磁界として当該磁界センサ素子に印加する
ことにより，外部磁界の大きさ及び極性を同時に検出す
ることを特徴とする磁界センサ．1. A soft magnetic thin film having a predetermined thickness and a width, which is divided into two by a space having a predetermined space length and is in contact with both sides of the space, and a giant magnetic resistance formed so as to fill the space. A magnetic field sensor element composed of a thin film and a magnetic field generation source, and by applying a magnetic field generated from the magnetic field generation source to the magnetic field sensor element as a bias magnetic field, the magnitude and polarity of the external magnetic field are detected at the same time. Magnetic field sensor characterized by the following.
らなる多層膜における当該硬磁性薄膜であり，当該硬磁
性薄膜によって生じた磁界を，バイアス磁界として磁界
センサ素子に印加することを特徴とする請求項１に記載
の磁界センサ．2. A magnetic field generation source is the hard magnetic thin film in a multilayer film composed of a soft magnetic thin film and a hard magnetic thin film, and the magnetic field generated by the hard magnetic thin film is applied to a magnetic field sensor element as a bias magnetic field. The magnetic field sensor according to claim 1, wherein the magnetic field sensor is a magnetic field sensor.
からなる多層膜における当該反強磁性薄膜であり，当該
反強磁性薄膜によって生じた磁界を，バイアス磁界とし
て磁界センサ素子に印加することを特徴とする請求項１
に記載の磁界センサ．3. A magnetic field generation source is the antiferromagnetic thin film in a multilayer film composed of a soft magnetic thin film and an antiferromagnetic thin film, and a magnetic field generated by the antiferromagnetic thin film is applied to a magnetic field sensor element as a bias magnetic field. Claim 1 characterized by the above.
Magnetic field sensor described in.
置した硬磁性体又は反強磁性体であり，当該硬磁性体又
は当該反強磁性体によって生じた磁界を，バイアス磁界
として当該磁界センサ素子に印加することを特徴とする
請求項１に記載の磁界センサ．4. The magnetic field generation source is a hard magnetic material or an antiferromagnetic material arranged outside the magnetic field sensor element, and the magnetic field generated by the hard magnetic material or the antiferromagnetic material is used as a bias magnetic field. The magnetic field sensor according to claim 1, wherein the magnetic field sensor is applied to the sensor element.
置した硬磁性薄膜又は反強磁性薄膜であり，当該硬磁性
薄膜又は当該反強磁性薄膜によって生じた磁界を，バイ
アス磁界として当該磁界センサ素子に印加することを特
徴とする請求項１に記載の磁界センサ．5. The magnetic field generation source is a hard magnetic thin film or an antiferromagnetic thin film arranged outside the magnetic field sensor element, and the magnetic field generated by the hard magnetic thin film or the antiferromagnetic thin film is used as a bias magnetic field. The magnetic field sensor according to claim 1, wherein the magnetic field sensor is applied to the sensor element.
若しくは近傍に配置した導電体又は導電体からなるコイ
ルであり，当該導電体又は当該導電体からなるコイルに
電流を流して生じた磁界を，バイアス磁界として当該磁
界センサ素子に印加することを特徴とする請求項１に記
載の磁界センサ．6. A magnetic field generation source is a conductor or a coil made of a conductor which is placed in close contact with or in the vicinity of a magnetic field sensor element, and is generated by passing a current through the conductor or a coil made of the conductor. The magnetic field sensor according to claim 1, wherein a magnetic field is applied to the magnetic field sensor element as a bias magnetic field.
若しくは近傍に配置した導電薄膜又は導電薄膜からなる
コイルであり，当該導電薄膜又は当該導電薄膜からなる
コイルに電流を流して生じた磁界を，バイアス磁界とし
て当該磁界センサ素子に印加することを特徴とする請求
項１に記載の磁界センサ．7. A magnetic field generation source is a conductive thin film or a coil made of a conductive thin film, which is placed in close contact with or near a magnetic field sensor element, and is generated by applying a current to the conductive thin film or the coil made of the conductive thin film. The magnetic field sensor according to claim 1, wherein a magnetic field is applied to the magnetic field sensor element as a bias magnetic field.
たことを特徴とする請求項１ないし請求項７のいずれか
１項に記載の磁界センサ．8. The magnetic field sensor according to claim 1, which is heat-treated at a temperature of 50 ° C. or more and 500 ° C. or less.
Priority Applications (9)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001316084A JP2003078187A (en) | 2001-09-05 | 2001-09-05 | Magnetic sensor |
| AT01978911T ATE434192T1 (en) | 2000-10-26 | 2001-10-25 | THIN FILM MAGNETIC FIELD SENSOR |
| KR1020027008326A KR100687513B1 (en) | 2000-10-26 | 2001-10-25 | Thin-film magnetic field sensor |
| TW090126413A TW550394B (en) | 2000-10-26 | 2001-10-25 | Thin-film magnetic field sensor |
| DE60139017T DE60139017D1 (en) | 2000-10-26 | 2001-10-25 | THIN FILM MAGNETIC SENSOR |
| CNB018032648A CN100403048C (en) | 2000-10-26 | 2001-10-25 | Thin-film magnetic field sensor |
| EP01978911A EP1329735B1 (en) | 2000-10-26 | 2001-10-25 | Thin-film magnetic field sensor |
| PCT/JP2001/009385 WO2002037131A1 (en) | 2000-10-26 | 2001-10-25 | Thin-film magnetic field sensor |
| US10/225,794 US6642714B2 (en) | 2000-10-26 | 2002-08-22 | Thin-film magnetic field sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001316084A JP2003078187A (en) | 2001-09-05 | 2001-09-05 | Magnetic sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003078187A true JP2003078187A (en) | 2003-03-14 |
| JP2003078187A5 JP2003078187A5 (en) | 2005-03-17 |
Family
ID=19134150
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001316084A Pending JP2003078187A (en) | 2000-10-26 | 2001-09-05 | Magnetic sensor |
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|---|---|---|---|---|
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| WO2008108387A1 (en) * | 2007-03-06 | 2008-09-12 | Alps Electric Co., Ltd. | Magnetic sensor device having multiple sensing axes |
| JP2011027418A (en) * | 2009-07-21 | 2011-02-10 | Asahi Kasei Electronics Co Ltd | Hall element |
| DE102011008704A1 (en) | 2010-01-21 | 2011-09-01 | Daido Tokushuko Kabushiki Kaisha | Thin-film magnetic sensor and method for its production |
| DE102011087342A1 (en) * | 2011-11-29 | 2013-05-29 | Leibniz-Institut Für Festkörper- Und Werkstoffforschung Dresden E.V. | USE OF FLEXIBLE MAGNETIC THIN SENSOR ELEMENTS |
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- 2001-09-05 JP JP2001316084A patent/JP2003078187A/en active Pending
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006066821A (en) * | 2004-08-30 | 2006-03-09 | Yamaha Corp | Magnetic sensor having magneto-resistance effect element |
| WO2008108387A1 (en) * | 2007-03-06 | 2008-09-12 | Alps Electric Co., Ltd. | Magnetic sensor device having multiple sensing axes |
| JP2011027418A (en) * | 2009-07-21 | 2011-02-10 | Asahi Kasei Electronics Co Ltd | Hall element |
| DE102011008704A1 (en) | 2010-01-21 | 2011-09-01 | Daido Tokushuko Kabushiki Kaisha | Thin-film magnetic sensor and method for its production |
| US9304176B2 (en) | 2010-01-21 | 2016-04-05 | Daido Tokushuko Kabushiki Kaisha | Thin-film magnetic sensor including a GMR film and method for manufacturing the same |
| DE102011087342A1 (en) * | 2011-11-29 | 2013-05-29 | Leibniz-Institut Für Festkörper- Und Werkstoffforschung Dresden E.V. | USE OF FLEXIBLE MAGNETIC THIN SENSOR ELEMENTS |
| DE102017122123A1 (en) | 2016-09-29 | 2018-03-29 | Daido Steel Co., Ltd. | Thin-film magnetic sensor |
| JP2018179776A (en) * | 2017-04-13 | 2018-11-15 | 大同特殊鋼株式会社 | Thin film magnetic sensor |
| CN111370570A (en) * | 2020-03-11 | 2020-07-03 | 武汉科技大学 | Oscillator for vertical current driving double-layer nanobelt internal transverse domain wall oscillation |
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