JPH0447890B2 - - Google Patents
Info
- Publication number
- JPH0447890B2 JPH0447890B2 JP60272757A JP27275785A JPH0447890B2 JP H0447890 B2 JPH0447890 B2 JP H0447890B2 JP 60272757 A JP60272757 A JP 60272757A JP 27275785 A JP27275785 A JP 27275785A JP H0447890 B2 JPH0447890 B2 JP H0447890B2
- Authority
- JP
- Japan
- Prior art keywords
- film
- thin film
- sio
- head
- magnetic
- 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.)
- Expired - Lifetime
Links
- 230000005291 magnetic effect Effects 0.000 claims description 50
- 239000010409 thin film Substances 0.000 claims description 35
- 230000005294 ferromagnetic effect Effects 0.000 claims description 7
- 239000010408 film Substances 0.000 description 47
- 239000010410 layer Substances 0.000 description 43
- 238000000034 method Methods 0.000 description 28
- 229910045601 alloy Inorganic materials 0.000 description 19
- 239000000956 alloy Substances 0.000 description 19
- 229910003271 Ni-Fe Inorganic materials 0.000 description 14
- 229910000889 permalloy Inorganic materials 0.000 description 12
- 229910004298 SiO 2 Inorganic materials 0.000 description 11
- 238000009792 diffusion process Methods 0.000 description 11
- 239000004020 conductor Substances 0.000 description 9
- 239000000758 substrate Substances 0.000 description 7
- 238000010438 heat treatment Methods 0.000 description 6
- 230000005415 magnetization Effects 0.000 description 6
- 238000001552 radio frequency sputter deposition Methods 0.000 description 6
- 230000008859 change Effects 0.000 description 5
- 238000000992 sputter etching Methods 0.000 description 5
- 229910018182 Al—Cu Inorganic materials 0.000 description 4
- ROOXNKNUYICQNP-UHFFFAOYSA-N ammonium persulfate Chemical compound [NH4+].[NH4+].[O-]S(=O)(=O)OOS([O-])(=O)=O ROOXNKNUYICQNP-UHFFFAOYSA-N 0.000 description 4
- 238000000137 annealing Methods 0.000 description 4
- 229910052802 copper Inorganic materials 0.000 description 4
- 238000005566 electron beam evaporation Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 229910000859 α-Fe Inorganic materials 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- 238000003486 chemical etching Methods 0.000 description 3
- 238000005229 chemical vapour deposition Methods 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000004907 flux Effects 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 230000035699 permeability Effects 0.000 description 3
- 230000002265 prevention Effects 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 2
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- 229910001870 ammonium persulfate Inorganic materials 0.000 description 2
- 230000002542 deteriorative effect Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 239000011241 protective layer Substances 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 229910017061 Fe Co Inorganic materials 0.000 description 1
- 229910000640 Fe alloy Inorganic materials 0.000 description 1
- 229910017709 Ni Co Inorganic materials 0.000 description 1
- 229910003267 Ni-Co Inorganic materials 0.000 description 1
- 229910003262 Ni‐Co Inorganic materials 0.000 description 1
- 229910018605 Ni—Zn Inorganic materials 0.000 description 1
- -1 Si 3 N 4 Inorganic materials 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 125000000896 monocarboxylic acid group Chemical group 0.000 description 1
- CHWRSCGUEQEHOH-UHFFFAOYSA-N potassium oxide Chemical compound [O-2].[K+].[K+] CHWRSCGUEQEHOH-UHFFFAOYSA-N 0.000 description 1
- 229910001950 potassium oxide Inorganic materials 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/33—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only
- G11B5/39—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using magneto-resistive devices or effects
- G11B5/3903—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using magneto-resistive devices or effects using magnetic thin film layers or their effects, the films being part of integrated structures
- G11B5/3906—Details related to the use of magnetic thin film layers or to their effects
- G11B5/3916—Arrangements in which the active read-out elements are coupled to the magnetic flux of the track by at least one magnetic thin film flux guide
- G11B5/3919—Arrangements in which the active read-out elements are coupled to the magnetic flux of the track by at least one magnetic thin film flux guide the guide being interposed in the flux path
- G11B5/3922—Arrangements in which the active read-out elements are coupled to the magnetic flux of the track by at least one magnetic thin film flux guide the guide being interposed in the flux path the read-out elements being disposed in magnetic shunt relative to at least two parts of the flux guide structure
- G11B5/3925—Arrangements in which the active read-out elements are coupled to the magnetic flux of the track by at least one magnetic thin film flux guide the guide being interposed in the flux path the read-out elements being disposed in magnetic shunt relative to at least two parts of the flux guide structure the two parts being thin films
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Magnetic Heads (AREA)
Description
＜技術分野＞
本発明は一軸磁気異方性を有する磁性薄膜に信
号磁界を印加し、それを磁化容易軸方向の電気抵
抗変化として検出する磁気抵抗効果素子（以下、
MR素子という）を具備して磁気記録媒体に記録
される信号の検出を行なう薄膜磁気ヘツド（以
下、薄膜MRヘツドといる）に関する。
＜従来技術＞
従来、薄膜MRヘツドは巻線型の磁気ヘツドと
比較して多くの利点があることが知られている。
この薄膜MRヘツドは、磁気テープ等の磁気記録
媒体に書き込まれた信号磁界を受けることによ
り、MR素子内部の磁化方向が変化し、この磁化
方向の変化に応じたMR素子の内部抵抗の変化を
外部出力として取り出すものである。従つて、薄
膜MRヘツドは磁束応答型のヘツドであり、磁気
記録媒体の移送速度に依存せずに信号磁界を再生
できる。又、この薄膜MRヘツドは半導体の微細
加工技術を適用することにより高集積化及び多素
子化が容易であるので、高密度記録が行なわれる
固定ヘツド式PCM録音機の再生用磁気ヘツドと
して有望視されている。
この様なMR素子は外部磁界に対して２乗変化
を示す感応特性をもつことから、MR素子を再生
ヘツドとして構成する場合には、素子形状をスト
ライプ状にするとともに、線型応答特性を得るた
めに所定のバイアス磁界を印加する構成を備える
ことが必要である。このバイアス磁界を印加する
方法には、導体に直流電流を流すことによりバイ
アス磁界を誘起する方法及びCo−Ｐ層等の高抗
磁力薄膜を用いてバイアス磁界を印加する方法等
が知られている。実際の使用に際しては、薄膜
MRヘツドでは、上記導体または高抗磁力薄膜の
上に絶縁層を介してMR素子が形成される。
一方、MR素子単体で構成した薄膜MRヘツド
よりも、MR素子をヘツド先端から離して磁気記
録媒体に発生した磁束をMR素子まで導く磁束導
入路（以下、ヨークという）を配置した第３図の
ような構造の通常ヨークタイプMRヘツド（以
下、YMRヘツドという）と呼ばれる薄膜磁気ヘ
ツドの方が信号の分解能の向上やMR素子の耐久
性の向上に有効であることが知られている。尚、
第３図は従来のYMRヘツドのトラツク幅方向に
垂直な方向の断面構造を示し、第４図はこの
YMRヘツドの平面構成を示す。但し、第３図は
第４図のYMRヘツドのＡ−Ｂ断面の構造を示
す。
同図で上部ヨーク１２は、通常膜厚が0.5〜
1.0μm程度のパーマロイ（Ni−Fe合金）膜で作
製され、磁気記録媒体２で発生した磁界をMR素
子７に導くための磁路となる。バイアス磁界を印
加するためにAl、CuまたはAl−Cu合金等の膜か
らなる導体４が配設される。ヘツドギヤツプ部１
３は実際に使用される記録波長が0.5μm程度であ
るので、0.2〜0.3μm程度に設定される。下部ヨー
クを形成する基板１は高透磁率磁性体からなり、
Ni−Znフエライト又はMn−Znフエライトが用
いられる。MR素子７はパーマロイ（Ni−Fe合
金）蒸着膜で作製され、トラツク幅は多トラツク
構成となるため50〜200μm程度に設定される。上
述の導体４、MR素子７及び上部ヨーク１２は基
板１上に絶縁層３，５，１０を介して形成され
る。
ところで、薄膜MR素子として使用される金属
強磁性薄膜の膜厚は200〜500〓と非常に薄く、従
つて、この金属強磁性薄膜と両側の絶縁層との間
にわずかの拡散等が生じても薄膜MR素子の特性
に著しく多きな影響を与えることになる。この拡
散等による薄膜MR素子の特性劣化について知る
為に、膜厚320〓のパーマロイ膜を真空中で200〜
250℃、２時間アニールした時のパーマロイ膜の
磁気特性の変化を調べた結果を第１表に示す。同
表でHcはパーマロイ膜の磁化容易軸方向の保磁
力、Hchはパーマロイ膜の磁化困難軸方向の保磁
力、Hkは異方性磁界、λsは磁歪定数を示す。
<Technical field> The present invention applies a signal magnetic field to a magnetic thin film having uniaxial magnetic anisotropy and detects it as a change in electrical resistance in the direction of the easy axis of magnetization.
The present invention relates to a thin film magnetic head (hereinafter referred to as a thin film MR head) that is equipped with an MR element (hereinafter referred to as a thin film MR head) and detects a signal recorded on a magnetic recording medium. <Prior Art> It has been known that thin-film MR heads have many advantages over wire-wound magnetic heads.
In this thin-film MR head, the magnetization direction inside the MR element changes by receiving a signal magnetic field written on a magnetic recording medium such as a magnetic tape, and the internal resistance of the MR element changes in accordance with the change in the magnetization direction. It is taken out as an external output. Therefore, the thin film MR head is a magnetic flux responsive head and can reproduce a signal magnetic field without depending on the transport speed of the magnetic recording medium. In addition, this thin-film MR head can be easily integrated and multi-elemented by applying semiconductor microfabrication technology, so it is seen as a promising magnetic head for playback in fixed-head PCM recorders that perform high-density recording. has been done. Since such an MR element has a sensitivity characteristic that shows a square change in response to an external magnetic field, when configuring an MR element as a reproduction head, it is necessary to make the element shape striped and to obtain linear response characteristics. It is necessary to provide a configuration for applying a predetermined bias magnetic field to the magnetic field. Known methods for applying this bias magnetic field include a method of inducing a bias magnetic field by flowing a direct current through a conductor, and a method of applying a bias magnetic field using a high coercive force thin film such as a Co-P layer. . In actual use, thin film
In the MR head, an MR element is formed on the conductor or high coercive force thin film with an insulating layer interposed therebetween. On the other hand, compared to a thin-film MR head composed of a single MR element, the MR element shown in Fig. 3 is separated from the tip of the head and a magnetic flux introduction path (hereinafter referred to as yoke) is arranged to guide the magnetic flux generated in the magnetic recording medium to the MR element. It is known that a thin-film magnetic head with a structure like this, usually called a yoke type MR head (hereinafter referred to as YMR head), is more effective in improving signal resolution and durability of the MR element. still,
Figure 3 shows the cross-sectional structure of a conventional YMR head in the direction perpendicular to the track width direction, and Figure 4 shows this cross-sectional structure.
The planar configuration of the YMR head is shown. However, FIG. 3 shows the structure of the YMR head in FIG. 4 taken along the line AB. In the figure, the upper yoke 12 usually has a film thickness of 0.5~
It is made of a permalloy (Ni-Fe alloy) film of about 1.0 μm, and serves as a magnetic path for guiding the magnetic field generated in the magnetic recording medium 2 to the MR element 7. A conductor 4 made of a film of Al, Cu or Al-Cu alloy is provided to apply a bias magnetic field. Head gap part 1
3 is set to about 0.2 to 0.3 μm since the recording wavelength actually used is about 0.5 μm. The substrate 1 forming the lower yoke is made of a high permeability magnetic material,
Ni--Zn ferrite or Mn--Zn ferrite is used. The MR element 7 is made of a permalloy (Ni--Fe alloy) vapor-deposited film, and the track width is set to about 50 to 200 μm since it has a multi-track configuration. The conductor 4, MR element 7, and upper yoke 12 described above are formed on the substrate 1 with insulating layers 3, 5, and 10 interposed therebetween. By the way, the thickness of the metal ferromagnetic thin film used as a thin film MR element is extremely thin, at 200 to 500 mm, and therefore a slight amount of diffusion, etc. occurs between this metal ferromagnetic thin film and the insulating layers on both sides. This also has a significant effect on the characteristics of the thin film MR element. In order to learn about the characteristic deterioration of thin film MR elements due to this diffusion, etc., we tested a permalloy film with a thickness of 320 mm in a vacuum with a thickness of 200 mm.
Table 1 shows the results of examining changes in the magnetic properties of the permalloy film when it was annealed at 250°C for 2 hours. In the same table, Hc is the coercive force of the permalloy film in the direction of the easy axis of magnetization, Hch is the coercive force of the permalloy film in the direction of the hard axis of magnetization, Hk is the anisotropic magnetic field, and λs is the magnetostriction constant.
【表】
ここで300℃、２時間以上のアニールでは著し
く特性が劣化し、特に飽和磁化も減少しているこ
とからこの特性劣化はパーマロイ膜と下地の
SiO2との間の相互拡散によるものと考えられる。
一方アニール温度を200℃に下げても特性の劣化
が生じることから薄膜磁気ヘツドの加工プロセス
中の昇温によつて、薄膜MR素子の特性劣化が生
じる可能性があり、さらに、製品そのものの耐熱
性も悪いという問題がある。
＜発明の目的＞
本発明は薄膜磁気ヘツドに使用される薄膜MR
素子の耐熱性を向上させることにより、加工プロ
セス中の昇温あるいは高温雰囲気下での使用等の
熱的要因による薄膜MR素子の特性劣化を防止す
ることを目的とする。
＜実施例＞
以下、本発明に係る薄膜磁気ヘツドの一実施例
について、図面を参照して詳細に説明する。
第１図はYMRヘツドの磁気記録媒体のトラツ
ク幅方向に垂直な方向の断面構造を示す。
同図で上部ヨーク１２は膜厚が0.5〜1.0μm程度
のパーマロイ（Ni−Fe合金）等の高透磁率磁性
膜からなり、この上部ヨーク１２は磁気記録媒体
２で発生した磁界をMR素子７へ導くための磁路
となる。MR素子７はパーマロイ蒸着膜からな
り、その膜厚は200〜500Åであり、トラツク幅は
多トラツク構成となるため50〜200μm程度に設定
される。MR素子７は絶縁層５上に形成された絶
縁層SiO膜６の上に形成される。又、バイアス磁
界をMR素子７に印加するための導体層４はMo、
Cu、Al又はAl−Cu合金等の膜からなる。下部ヨ
ークを形成する基板１はNi−Znフエライト又は
Mn−Znフエライトから成る。この基板１上に絶
縁層３を介して導体層４が形成され、該導体層４
の上に絶縁層５とSiO膜６を介してMR素子７が
形成され、該MR素子７の上にSiO膜９と絶縁層
１０を介して上部ヨーク１２が形成される。
以上のヘツドの製作手順としては、先ず基板１
の上にSiO2、Si3N4、Al2O3等からなる絶縁層３
がRFスパツタ法又はＰ−CVD法等により形成さ
れる。次にこの絶縁層３の上にMo、Cu、Al、
Al−Cu合金等からなる導体層４が抵抗加熱法、
RFスパツタ法又は電子ビーム蒸着法等により形
成される。この導体層４を目的の形状に加工する
ために、ケミカルエツチング法、スパツタエツチ
ング法又はイオンミーリング法が用いられる。具
体例を上げて説明すると、ケミカルエツチング法
の場合、Cu膜は硝酸（HNO3）＋過硫酸アンモニ
ウム（（NH3）2S2O8）＋水（H2O）、Al−Cu膜は
水酸化カリウム（KOH）＋過硫酸アンモニウム
（（NH3）2S2O8）＋水（H2O）又はリン酸
（H3PO4）＋硝酸（HNO3）＋酢酸（CH3COOH）＋
水（H2O）なるエツチング液を用いれば良い。
スパツタエツチング法又はイオンミーリング法の
場合にはMo、Cu、Al−Cu等の膜はArガスを導
入すれば公知の手法によつて加工することができ
る。
上述のようにして形成された導体層４上にＰ−
CVD法又はRFスパツタ法によりSiO2、
Si3N4Al2O3等からなる絶縁層５が形成される。
次にSiO膜６が絶縁層５の上に形成される。この
SiO膜６は抵抗加熱法又は電子ビーム蒸着法によ
り形成される。該SiO膜６はSiO2層と同様に表面
平滑性、膜質が優れているので、MR素子７を形
成するパーマロイ（Ni−Fe合金）蒸着膜は第２
表に示すように良好な磁気特性をもつようにな
る。[Table] Here, annealing at 300°C for 2 hours or more significantly deteriorates the characteristics, and the saturation magnetization in particular decreases, so this deterioration of characteristics is due to the difference between the permalloy film and the underlying layer.
This is thought to be due to mutual diffusion with SiO 2 .
On the other hand, even if the annealing temperature is lowered to 200°C, the characteristics will deteriorate, so there is a possibility that the temperature increase during the manufacturing process of the thin-film magnetic head will cause the characteristics of the thin-film MR element to deteriorate.Furthermore, the heat resistance of the product itself may deteriorate. There is also the problem of bad sex. <Object of the invention> The present invention is directed to a thin film MR used in a thin film magnetic head.
By improving the heat resistance of the element, the purpose is to prevent the characteristics of the thin film MR element from deteriorating due to thermal factors such as temperature rise during the processing process or use in a high-temperature atmosphere. <Example> Hereinafter, an example of the thin film magnetic head according to the present invention will be described in detail with reference to the drawings. FIG. 1 shows a cross-sectional structure of a magnetic recording medium of a YMR head in a direction perpendicular to the track width direction. In the figure, the upper yoke 12 is made of a high permeability magnetic film such as permalloy (Ni-Fe alloy) with a film thickness of about 0.5 to 1.0 μm, and this upper yoke 12 transfers the magnetic field generated by the magnetic recording medium 2 to the MR element 7. It becomes a magnetic path to lead to. The MR element 7 is made of a permalloy vapor-deposited film, the film thickness of which is 200 to 500 Å, and the track width is set to about 50 to 200 μm since it has a multi-track configuration. The MR element 7 is formed on an insulating layer SiO film 6 formed on the insulating layer 5. Further, the conductor layer 4 for applying a bias magnetic field to the MR element 7 is made of Mo,
It consists of a film of Cu, Al, Al-Cu alloy, etc. The substrate 1 forming the lower yoke is made of Ni-Zn ferrite or
Consists of Mn-Zn ferrite. A conductor layer 4 is formed on this substrate 1 with an insulating layer 3 interposed therebetween.
An MR element 7 is formed on the MR element 7 with an insulating layer 5 and an SiO film 6 in between, and an upper yoke 12 is formed on the MR element 7 with an SiO film 9 and an insulating layer 10 in between. As for the manufacturing procedure of the above head, first, the board 1
An insulating layer 3 made of SiO 2 , Si 3 N 4 , Al 2 O 3 etc.
is formed by RF sputtering method or P-CVD method. Next, Mo, Cu, Al,
The conductor layer 4 made of Al-Cu alloy etc. is heated by resistance heating.
It is formed by RF sputtering method, electron beam evaporation method, etc. In order to process this conductor layer 4 into a desired shape, a chemical etching method, a sputter etching method, or an ion milling method is used. To explain with a specific example, in the case of the chemical etching method, Cu film is formed using nitric acid (HNO 3 ) + ammonium persulfate ((NH 3 ) 2 S 2 O 8 ) + water (H 2 O), and Al-Cu film is formed using water. Potassium oxide (KOH) + ammonium persulfate ((NH 3 ) 2 S 2 O 8 ) + water (H 2 O) or phosphoric acid (H 3 PO 4 ) + nitric acid (HNO 3 ) + acetic acid (CH 3 COOH) +
An etching solution such as water (H 2 O) may be used.
In the case of the sputter etching method or the ion milling method, films of Mo, Cu, Al--Cu, etc. can be processed by a known method by introducing Ar gas. P- on the conductor layer 4 formed as described above.
SiO 2 by CVD method or RF sputtering method,
An insulating layer 5 made of Si 3 N 4 Al 2 O 3 or the like is formed.
Next, a SiO film 6 is formed on the insulating layer 5. this
The SiO film 6 is formed by a resistance heating method or an electron beam evaporation method. Since the SiO film 6 has excellent surface smoothness and film quality like the SiO 2 layer, the permalloy (Ni-Fe alloy) vapor-deposited film forming the MR element 7 is the second layer.
As shown in the table, it has good magnetic properties.
【表】
上記MR素子７は、その膜厚が200〜500Åであ
り、ケミカルエツチング又はスパツタエツチング
法等により（５〜20）×（50〜100）μmのストライ
プ状に加工される。その後、リード部８が第４図
と同じ位置に抵抗加熱法、電子ビーム蒸着法ある
いはRFスパツタ法により形成される。次に、
MR素子７及びリード部８の上に抵抗加熱法又は
電子ビーム蒸着法によりSiO膜９を形成後、Ｐ−
CVD法又はRFスパツタ法により絶縁層SiO2膜１
０が蒸着され、最後に高透磁率磁性膜からなる上
部ヨーク１２が形成される。
ここでパーマロイ蒸着膜の下地層及び上側保護
層としてSiO層を用いた場合のパーマロイ蒸着膜
の特性について以下に述べる。
ガラス基板上に厚さ約400ÅのSiO層を抵抗加
熱法で形成した後厚さ約320ÅのNi−Fe（パーマ
ロイ）合金膜を磁場中にて抵抗加熱法で形成し、
該Ni−Fe合金膜上に厚さ約400ÅのSiOを形成し
た試料を磁場中で200℃、２時間真空中でアニー
ルした時の磁気特性の変化を第３表に示す。尚、
比較のため、Ni−Fe合金膜上に直接、SiO2層を
RFスパツタ法で形成した試料のアニールによる
磁気特性の変化も同表に示している。この表中の
磁歪定数Xsは外部から応力によるNi−Fe合金膜
の一軸異方性磁界の変化から容易に測定でき、し
かもNi−Fe合金膜の組成に著しく敏感であるこ
とからNi−Fe合金膜と下地との拡散による組成
変化を検出するのに適している。[Table] The MR element 7 has a film thickness of 200 to 500 Å, and is processed into a stripe shape of (5 to 20)×(50 to 100) μm by chemical etching or sputter etching. Thereafter, the lead portion 8 is formed at the same position as shown in FIG. 4 by a resistance heating method, an electron beam evaporation method, or an RF sputtering method. next,
After forming the SiO film 9 on the MR element 7 and lead part 8 by resistance heating method or electron beam evaporation method, P-
Insulating layer SiO 2 film 1 by CVD method or RF sputtering method
0 is deposited, and finally an upper yoke 12 made of a high permeability magnetic film is formed. Here, the characteristics of the permalloy vapor-deposited film when a SiO layer is used as the underlayer and upper protective layer of the permalloy-deposited film will be described below. After forming a SiO layer with a thickness of about 400 Å on a glass substrate using a resistance heating method, a Ni-Fe (permalloy) alloy film with a thickness of about 320 Å was formed using a resistance heating method in a magnetic field.
Table 3 shows the changes in magnetic properties when a sample in which SiO was formed to a thickness of about 400 Å on the Ni-Fe alloy film was annealed in a magnetic field at 200° C. for 2 hours in vacuum. still,
For comparison, two SiO layers were deposited directly on the Ni-Fe alloy film.
The same table also shows changes in magnetic properties due to annealing of samples formed using the RF sputtering method. The magnetostriction constant It is suitable for detecting compositional changes due to diffusion between the film and the substrate.
【表】
第３表からわかるように、Ni−Fe合金膜上に
直接絶縁層となるSiO2層を形成した場合にはア
ニールによつて磁歪定数は正から負に変化してお
り、このことはNi−Fe合金膜とSiO2層との拡散
によりNi−Fe合金膜中のFe成分が減少したこと
を示している。一方Ni−Fe合金膜上にSiO層を
形成した場合には磁歪定数の変化は非常に小さく
なつている。このことは薄膜MR素子となる
NiFe合金膜の両側にSiO層を設けることにより、
NiFe合金膜との拡散を防止することができるこ
とを示している。
上記の実験例で示したように、薄膜MR素子と
なるNi−Fe合金膜の両側に拡散防止層となる
SiO層を介在せしめ、絶縁層をSiO2とSiOの２層
構造とすることによりSiO2絶縁層とNi−Fe合金
膜との間の拡散を防止することができ、その結果
加工プロセス中の昇温あるいは製品使用時の温度
履歴等の熱的要因による薄膜MR素子の特性の劣
化を防止することができる。
第２図は他の実施例におけるYMRヘツドの磁
気記録媒体のトラツク幅方向に垂直な方向の断面
構成を示す。同図に示す様にMR素子７の上側保
護層９がGaP部を構成する絶縁層を兼用した構造
になつている。
以上の実施例ではMR素子としてNi−Fe合金
膜を使用した場合について示しているが、MR素
子としてはNi−Fe−Co、Ni−Co等の他の金属
強磁性膜を使用した場合にも同様な効果が得られ
る。
＜発明の効果＞
以上述べた本発明によれば、薄膜MR素子の耐
熱性を向上でき、加工プロセス中の昇温による特
性劣化の防止を図ることができる。また、本発明
における拡散防止層であるSiOは絶縁物なので、
導電層と異なり、電流の分流によるMR素子の感
度低下がないので、良好な特性（例えば抵効変化
率の特性）が得られる。また、本発明によれば、
絶縁層の少なくとも一方を２層構造としたので、
Ni−Fe合金膜との拡散を防止するためのSiO膜
（SiO2等に比較すると加工性の点で劣る）を薄く
構成することが可能となり加工性に優れた薄膜磁
気ヘツドを提供することができる。[Table] As can be seen from Table 3, when the SiO 2 layer, which serves as an insulating layer, is formed directly on the Ni-Fe alloy film, the magnetostriction constant changes from positive to negative due to annealing. shows that the Fe component in the Ni-Fe alloy film was reduced due to diffusion between the Ni-Fe alloy film and the SiO 2 layer. On the other hand, when the SiO layer is formed on the Ni-Fe alloy film, the change in the magnetostriction constant becomes very small. This makes it a thin film MR element.
By providing SiO layers on both sides of the NiFe alloy film,
This shows that diffusion with the NiFe alloy film can be prevented. As shown in the above experimental example, a diffusion prevention layer is formed on both sides of the Ni-Fe alloy film that becomes the thin film MR element.
By interposing the SiO layer and making the insulating layer a two-layer structure of SiO 2 and SiO, it is possible to prevent diffusion between the SiO 2 insulating layer and the Ni-Fe alloy film. It is possible to prevent the characteristics of the thin film MR element from deteriorating due to thermal factors such as temperature or temperature history during product use. FIG. 2 shows a cross-sectional structure of a magnetic recording medium of a YMR head in another embodiment in a direction perpendicular to the track width direction. As shown in the figure, the upper protective layer 9 of the MR element 7 has a structure in which it also serves as an insulating layer constituting the GaP section. The above example shows the case where a Ni-Fe alloy film is used as the MR element, but it is also possible to use other metal ferromagnetic films such as Ni-Fe-Co and Ni-Co as the MR element. A similar effect can be obtained. <Effects of the Invention> According to the present invention described above, the heat resistance of the thin film MR element can be improved, and deterioration of characteristics due to temperature rise during the processing process can be prevented. In addition, since SiO, which is the diffusion prevention layer in the present invention, is an insulator,
Unlike a conductive layer, there is no reduction in sensitivity of the MR element due to current shunting, so good characteristics (for example, resistance change rate characteristics) can be obtained. Further, according to the present invention,
Since at least one of the insulating layers has a two-layer structure,
It is possible to make the SiO film (inferior in workability compared to SiO 2 etc.) thin to prevent diffusion with the Ni-Fe alloy film, making it possible to provide a thin film magnetic head with excellent workability. can.
第１図は本発明に係る一実施例の断面図、第２
図は本発明に係る他の実施例の断面図、第３図は
従来の薄膜MRヘツドの断面図、第４図はその平
面図である。
図中、１……基板、２……磁気記録媒体、３，
５，１０……絶縁層SiO2、４……導電層、６，
９……拡散防止層SiO、７……MR素子、８……
リード層、１１……バツクヨーク部、１２……上
部ヨーク、１３……フロント・ギヤツプ部。
FIG. 1 is a sectional view of one embodiment of the present invention, and FIG.
3 is a sectional view of another embodiment of the present invention, FIG. 3 is a sectional view of a conventional thin film MR head, and FIG. 4 is a plan view thereof. In the figure, 1...Substrate, 2...Magnetic recording medium, 3,
5, 10... Insulating layer SiO 2 , 4... Conductive layer, 6,
9... Diffusion prevention layer SiO, 7... MR element, 8...
Lead layer, 11... Back yoke portion, 12... Upper yoke, 13... Front gap portion.
Claims (1)
絶縁層間に挟まれて形成された一軸磁気異方性を
有する強磁性薄膜の電気抵抗変化として検出する
磁気抵抗効果型の薄膜磁気ヘツドにおいて、 前記強磁性薄膜を挟む第１と第２の絶縁層の少
なくとも一方が２層構造をなし、かつ、前記第１
と第２の絶縁層の前記強磁性薄膜に接する層が共
にSiOから成ることを特徴とする薄膜磁気ヘツ
ド。[Claims] 1. A magnetoresistive device that detects changes in an applied signal magnetic field as changes in electrical resistance of a ferromagnetic thin film having uniaxial magnetic anisotropy formed between first and second insulating layers. In the effective type thin film magnetic head, at least one of the first and second insulating layers sandwiching the ferromagnetic thin film has a two-layer structure, and the first and second insulating layers sandwich the ferromagnetic thin film.
and a second insulating layer in contact with the ferromagnetic thin film, both of which are made of SiO.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27275785A JPS62132211A (en) | 1985-12-03 | 1985-12-03 | Thin film magnetic head |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27275785A JPS62132211A (en) | 1985-12-03 | 1985-12-03 | Thin film magnetic head |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62132211A JPS62132211A (en) | 1987-06-15 |
| JPH0447890B2 true JPH0447890B2 (en) | 1992-08-05 |
Family
ID=17518326
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27275785A Granted JPS62132211A (en) | 1985-12-03 | 1985-12-03 | Thin film magnetic head |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62132211A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2816150B2 (en) * | 1988-01-22 | 1998-10-27 | 株式会社日立製作所 | Composite magnetic head |
| JP2790811B2 (en) * | 1988-04-20 | 1998-08-27 | シャープ株式会社 | Thin film magnetic head |
| JP2731506B2 (en) * | 1993-11-22 | 1998-03-25 | 富士通株式会社 | Magnetoresistive magnetic head and method of manufacturing the same |
| US7394626B2 (en) | 2002-11-01 | 2008-07-01 | Nec Corporation | Magnetoresistance device with a diffusion barrier between a conductor and a magnetoresistance element and method of fabricating the same |
| JP2004200245A (en) | 2002-12-16 | 2004-07-15 | Nec Corp | Magnetoresistive element and manufacturing method therefor |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6045922A (en) * | 1983-08-23 | 1985-03-12 | Fujitsu Ltd | Magneto-resistance effect type magnetic head |
-
1985
- 1985-12-03 JP JP27275785A patent/JPS62132211A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6045922A (en) * | 1983-08-23 | 1985-03-12 | Fujitsu Ltd | Magneto-resistance effect type magnetic head |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62132211A (en) | 1987-06-15 |
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