JPH08106630A - Magnetic recording medium and substrate - Google Patents
Magnetic recording medium and substrateInfo
- Publication number
- JPH08106630A JPH08106630A JP24136994A JP24136994A JPH08106630A JP H08106630 A JPH08106630 A JP H08106630A JP 24136994 A JP24136994 A JP 24136994A JP 24136994 A JP24136994 A JP 24136994A JP H08106630 A JPH08106630 A JP H08106630A
- Authority
- JP
- Japan
- Prior art keywords
- substrate
- magnetic
- recording medium
- magnetic recording
- protrusion
- 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.)
- Granted
Links
Landscapes
- Magnetic Record Carriers (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、磁気記録媒体および基
板に関し、詳しくは磁気ディスク装置に使用されるハー
ドティスクなどの磁気記録媒体およびそのための基板に
関するものである。特に、良好なＣＳＳ（コンタクトス
タートアンドストップ）特性およびヘッドの媒体表面へ
のスティッキング特性とヘッドの低浮上化を同時に可能
にする薄膜型の磁気記録媒体ならびにその基板に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording medium and a substrate, and more particularly to a magnetic recording medium such as a hard disk used in a magnetic disk device and a substrate therefor. In particular, the present invention relates to a thin film magnetic recording medium and a substrate thereof, which can simultaneously achieve good CSS (contact start and stop) characteristics, sticking characteristics of the head to the medium surface, and low flying height of the head.
【０００２】[0002]
【従来の技術】通常、ハードディスクはその使用に際し
高速で回転して磁気ヘッドを浮上させ、ハードディスク
への書き込み／読み出し等をこの磁気ヘッドを介して行
っている。ハードディスクは、その磁気特性の向上のた
め、ディスクの基板面あるいは基板面上に設けられたＮ
ｉＰメッキ等の非磁性体からなる下地層上に、磁気ディ
スクの円周方向にほぼ同心円状に機械的研磨を行って加
工痕を残す加工（以下、機械的テキスチャという）が行
われている。2. Description of the Related Art Normally, a hard disk rotates at a high speed during its use so that a magnetic head is levitated, and writing / reading to / from the hard disk is performed via this magnetic head. A hard disk has a substrate surface of the disk or an N provided on the substrate surface in order to improve its magnetic characteristics.
On an underlayer made of a non-magnetic material such as iP plating, mechanical polishing is performed substantially concentrically in the circumferential direction of a magnetic disk to leave machining marks (hereinafter referred to as mechanical texture).
【０００３】近年の情報量の増大と装置の小型軽量化の
要求により、線記録密度及びトラック密度が高くなり、
１ビット当りの面積が小さくなってくると、従来のよう
な機械的テキスチャによるスクラッチ傷は情報読み出し
の際にエラーとなる確率が高くなる。また、内周部にあ
るＣＳＳゾーンのみに機械的テキスチャを施しデータ記
録領域はそのままにする方法もあるが、データ記録領域
の面がＣＳＳゾーンの面の高さよりも高くなり、ヘッド
がシークする時にクラッシュするという問題があった。Due to the recent increase in the amount of information and the demand for smaller and lighter devices, the linear recording density and track density have increased,
As the area per bit becomes smaller, scratches due to mechanical texture as in the conventional case have a higher probability of becoming an error in reading information. There is also a method of mechanically texturing only the CSS zone on the inner periphery and leaving the data recording area as it is, but when the surface of the data recording area is higher than the height of the surface of the CSS zone and the head seeks. There was a problem of crashing.
【０００４】また、こうした機械的テキスチャに代え
て、レーザでテキスチャパターンを作る方法も提案され
ている。レーザによるテキスチャの方法の例は、米国特
許第５，０６２，０２１号、同５，１０８，７８１号に
開示されており、Ｎｄ−ＹＡＧの強パルスレーザ光によ
りＮｉＰ層を局所的に溶融し、図３に示すように、溶融
して形成された凹状の穴部６とその周囲に溶融したＮｉ
Ｐが表面張力で盛り上がって固化した直径が２．５〜１
００μｍのリム部７からなるクレータ状の凹凸を多数作
り、円環状の凸状リムによってヘッドとのＣＳＳ特性を
改善する試みが提案されている。しかし、この方法では
ヘッド下面との接触面積が飛躍的には下がらず、ヘッド
とディスク間のスティッキングの問題は、機械的テキス
チャに較べて改善されているとは言い難い。Also, a method of making a texture pattern by a laser has been proposed in place of such a mechanical texture. An example of a laser texture method is disclosed in US Pat. Nos. 5,062,021 and 5,108,781, in which a NiP layer is locally melted by a strong pulsed laser beam of Nd-YAG, As shown in FIG. 3, the concave hole portion 6 formed by melting and Ni melted around it
The diameter of the solidified P that rises due to surface tension is 2.5 to 1
There has been proposed an attempt to form a large number of crater-shaped irregularities composed of a rim portion 7 of 00 μm and improve the CSS characteristics with the head by using an annular convex rim. However, with this method, the contact area with the lower surface of the head is not drastically reduced, and it is hard to say that the problem of sticking between the head and the disk is improved as compared with the mechanical texture.
【０００５】また、突起をフォトリソグラフィを使って
形成する方法も提案されており、日本潤滑学会トライボ
ロジー予稿集（１９９１−５，Ａ−１１），（１９９２
−１０，Ｂ−６）には、ディスクの全表面に対する面積
比が０．１〜５％の同心円状の凸部又は突起を、フォト
リソグラフィによってＮｉＰ下地層を成膜したＡｌ合金
基板上に形成させ、その上にＣｒ層、Ｃｏ合金磁性層、
Ｃ保護膜を順次成膜した磁気ディスクのＣＳＳテストの
結果が示されている。しかし、この方法では、突起の頂
部が平滑なため、ヘッドの摺動回数と共に摩擦が増加す
るという欠点があり、また工業化も容易でないという問
題があった。A method of forming protrusions using photolithography has also been proposed, and the tribology preliminary papers of the Japan Lubricating Society (1991-5, A-11), (1992).
-10, B-6), a concentric convex portion or projection having an area ratio of 0.1 to 5% to the entire surface of the disk is formed on an Al alloy substrate on which a NiP underlayer is formed by photolithography. And a Cr layer, a Co alloy magnetic layer, and
The result of the CSS test of the magnetic disk in which the C protective film is sequentially formed is shown. However, in this method, since the tops of the protrusions are smooth, there is a drawback that friction increases with the number of times the head slides, and there is a problem that industrialization is not easy.
【０００６】[0006]
【発明が解決しようとする課題】したがって、ＣＳＳゾ
ーンでは、突起の先端の面積を小さくしてヘッドとのス
ティッキングをなくし、しかも平均的な面の高さは、デ
ータゾーンとほぼ同じにして、ヘッドをデータゾーン、
ＣＳＳゾーン間でシークした時にヘッドの安定浮上高さ
の変動が少なく、ヘッドクラッシュやヘッドの空間での
不安定化が起こらない磁気記録媒体が望まれている。Therefore, in the CSS zone, the area of the tip of the protrusion is reduced to eliminate sticking with the head, and the average height of the surface is made substantially the same as that of the data zone. The data zone,
There is a demand for a magnetic recording medium in which fluctuation of the stable flying height of the head is small when seeking between CSS zones, and head crash and destabilization in the space of the head do not occur.
【０００７】[0007]
【課題を解決するための手段】本発明はこうした高密度
磁気記録用の媒体に対してなされたもので、その第１の
要旨は、非磁性基板上に、少なくとも磁性層を有する磁
気記録媒体であって、非磁性基板の磁性層側表面に、高
さが１〜６０ｎｍの突起を１ｍｍ2 あたり１０ 2 〜１０
8 個有し、且つ、各突起の頂点から１ｎｍ下の高さにお
ける等高線で囲まれた図形の面積の平均値が２μｍ2 以
下であることを特徴とする磁気記録媒体、に存する。更
に、本発明の第２の要旨は、非磁性基板上に少なくとも
磁性層を有する磁気記録媒体用基板であって、非磁性基
板の磁性層側表面に高さが１〜６０ｎｍの突起を１ｍｍ
2 あたり１０2 〜１０8 個有し、且つ、各突起の頂点か
ら１ｎｍ下の高さにおける等高線で囲まれた図形の面積
の平均値が２μｍ2 以下であることを特徴とする磁気記
録媒体用基板、に存する。以下、本発明を詳細に説明す
る。The present invention provides such a high density.
It was made for a magnetic recording medium,
The gist is that a magnetic layer having at least a magnetic layer on a non-magnetic substrate.
A magnetic recording medium, which has a high magnetic field on the magnetic layer side surface of the non-magnetic substrate.
1 mm for protrusions with a size of 1 to 60 nm2Per 10 2-10
8Each one has a height of 1 nm below the top of each protrusion.
The average value of the area of the figure surrounded by the contour line is 2 μm2Since
And a magnetic recording medium characterized by being below. Change
The second gist of the present invention is to provide at least a non-magnetic substrate.
A magnetic recording medium substrate having a magnetic layer, comprising a non-magnetic group
1 mm protrusion with a height of 1 to 60 nm on the magnetic layer side surface of the plate
2Per 102-108It has one and is the top of each protrusion
Area of the figure surrounded by contour lines at a height of 1 nm below
Average value of 2 μm2Magnetic recording characterized by
It exists in the substrate for recording media. Hereinafter, the present invention will be described in detail.
You.
【０００８】本発明において、非磁性基板の磁性層側表
面に存在する突起の高さは、ＪＩＳ表面粗さ（Ｂ０６０
１）により規定される、粗さ曲線の中心線を基準とした
場合の突起の高さを表す。この突起の高さは、好ましく
は１〜６０ｎｍ、更に好ましくは１０〜４０ｎｍであ
り、６０ｎｍを超えるとＣＳＳ特性は良いがヘッドの安
定浮上高さは下げられず、１ｎｍ未満では基板が元来有
する細かな凹凸に埋もれてしまい所望の効果は得られな
い。また、本発明においては、非磁性基板の磁性層側表
面に、高さが１〜６０ｎｍの突起を１ｍｍ2 あたり１０
2 〜１０8 個有する。１０2 個未満では基板のうねり等
によりヘッド下面を突起のみで支えるのは難しく、また
１０8 個を超えた突起を作ろうとすると互いに干渉しあ
って突起の高さをそろえるのが難しくなり、その好まし
い存在密度は１ｍｍ2 あたり１０3〜１０6 個である。
ここで突起の存在密度は媒体全体での平均密度ではな
く、突起存在部での単位面積当たりの密度をいう。In the present invention, the height of the protrusions present on the surface of the non-magnetic substrate on the magnetic layer side is determined by the JIS surface roughness (B060).
The height of the protrusion when the center line of the roughness curve defined by 1) is used as a reference. The height of this protrusion is preferably 1 to 60 nm, more preferably 10 to 40 nm. If it exceeds 60 nm, the CSS characteristics are good, but the stable flying height of the head cannot be lowered, and if it is less than 1 nm, the substrate originally has it. The desired effect cannot be obtained because it is buried in fine irregularities. Further, in the present invention, protrusions having a height of 1 to 60 nm are provided on the surface of the non-magnetic substrate on the magnetic layer side at a rate of 10 per 1 mm 2.
It has 2 to 10 8 . If the number is less than 10 2 , it is difficult to support the lower surface of the head only by the protrusions due to the waviness of the substrate, and if the number of protrusions exceeds 10 8 , it becomes difficult to make the heights of the protrusions interfere with each other. The preferable existence density is 10 3 to 10 6 per 1 mm 2 .
Here, the density of protrusions is not the average density of the entire medium, but the density per unit area in the protrusion existing portion.
【０００９】また、本発明における各突起は、その頂点
から１ｎｍ下の高さにおける等高線で囲まれた図形の面
積の平均値（以下、等高線面積という）が２μｍ2 以下
であり、好ましくは、０．００１〜１．０μｍ2 、より
好ましくは０．００１〜０．５μｍ2 、更に好ましくは
０．００１〜０．２μｍ2 の範囲の値を有する。２μｍ
2 を超えるとヘッドとの間にスティッキングが発生しや
すくなり、ＣＳＳを作動することは不可能となる。な
お、この等高線面積は、レーザ干渉による表面形状測定
装置、例えば、米国ザイゴ社製〔ＺＹＧＯ〕で測定が可
能である。Further, in each projection in the present invention, the average value of the area of a figure surrounded by contour lines at a height 1 nm below the apex (hereinafter referred to as contour line area) is 2 μm 2 or less, preferably 0. .001~1.0μm 2, more preferably 0.001 to 0.5 [mu] m 2, more preferably having a value ranging from 0.001~0.2μm 2. 2 μm
If the number exceeds 2 , sticking tends to occur between the head and the head, making it impossible to operate the CSS. The contour line area can be measured by a surface shape measuring device using laser interference, for example, [ZYGO] manufactured by Zygo, Inc., USA.
【０００１０】本発明の媒体の好ましい態様として、突
起は磁気ヘッドがＣＳＳ（コンタクトスタートアンドス
トップ）を行なう領域のみに存在し、データ記録領域に
は存在しない磁気記録媒体が挙げられる。このような構
成にするとにより、データ記録領域においては磁性層表
面を平滑にすることができるため、従来のようなスクラ
ッチ傷によるエラーを減少させることができる。また、
さらに好ましい態様として、突起が磁気ヘッドがＣＳＳ
を行なう領域のみに存在しデータ記録領域には存在せ
ず、かつその突起の高さがデータ記録領域に向かって減
少している磁気記録媒体、または、その突起の密度がデ
ータ記録領域に向かって減少している磁気記録媒体が挙
げられる。突起高さをデータ記録領域に向かって減少さ
せることにより、データ記録領域からＣＳＳゾーンある
いは逆の方向にヘッドを安定にシークすることができ
る。また、突起の密度をデータ記録領域に向かって減少
させることにより、突起高さを順次変化させた場合と同
様な効果を得ることができる。また、突起の高さおよび
密度の両方をデータ記録領域に向かって減少させること
も好ましい方法である。As a preferred embodiment of the medium of the present invention, there is a magnetic recording medium in which the protrusion exists only in the area where the magnetic head performs CSS (contact start and stop) and does not exist in the data recording area. With such a structure, the surface of the magnetic layer can be made smooth in the data recording area, so that errors due to scratches as in the prior art can be reduced. Also,
In a further preferred embodiment, the protrusion is the magnetic head and the CSS is
Exists only in the area that does not exist in the data recording area, and the height of the protrusion decreases toward the data recording area, or the density of the protrusion increases toward the data recording area. There is a decreasing number of magnetic recording media. By decreasing the protrusion height toward the data recording area, the head can be stably sought from the data recording area to the CSS zone or the opposite direction. Further, by decreasing the density of the protrusions toward the data recording area, it is possible to obtain the same effect as that when the height of the protrusions is sequentially changed. It is also a preferable method to reduce both the height and density of the protrusions toward the data recording area.
【００１１】本発明の磁気記録媒体を製造するための好
ましい方法としては、Ｓｉのミラーウェハーのように極
めて平滑な表面を有する磁気記録媒体用基板を回転させ
ながら、その表面に円周方向に沿って、出力を精度良く
制御したエネルギービームを照射して表面に突起を形成
する方法等が挙げられる。エネルギービームとしては、
パルスレーザ、電子線、Ｘ線などが挙げられ、中でもパ
ルスレーザを用いることが好ましく、以下、パルスレー
ザを用いた場合を例として本発明を説明する。A preferred method for producing the magnetic recording medium of the present invention is to rotate a magnetic recording medium substrate having an extremely smooth surface such as a Si mirror wafer while rotating the substrate along the circumferential direction. Then, a method of forming projections on the surface by irradiating an energy beam whose output is accurately controlled is cited. As an energy beam,
A pulse laser, an electron beam, an X-ray, and the like can be given. Among them, it is preferable to use a pulse laser, and the present invention will be described below by taking the case of using a pulse laser as an example.
【００１２】本発明において、突起の生成機構は未だ十
分解明されていないが、次のように考えられる。図２は
突起の予想される生成機構を示す概念図である。図２
（ａ）で、パルスレーザ３が照射された非磁性基板４の
局所的に過熱されたスポット部５は一部溶融し、基板の
回転（方向を矢印で示す）、またはレーザビームの走査
によって溶融部分が移動する。図２（ｂ）に示すように
最初にビームが当った部分はその後、温度が下がり温度
勾配が生ずる。一般に、溶融液体においては、低温側の
方が表面張力が大きく、この表面張力の差により、最初
にビームで照射され溶融しその後低温になった部分が、
後から溶融した部分の液体を取り込み盛り上がる。した
がって、図２（ｃ）に示すように、最後に溶融した部分
には凹部ができ、レーザビームの走査方向に対して突起
の後部に凹部を有することとなる。つまり、突起の中心
を通り、レーザビームの走査方向を含む垂直断面形状
が、突起底部の片側部分に凹部を有することとなる。本
発明において、レーザビームの走査方向とは、静止した
ディスク上でレーザビームが走査する方向のみならず、
レーザビームは静止させておき、ディスクを回転させた
状態で照射する場合のディスクの回転方向をも示すこと
とする。In the present invention, the mechanism of formation of protrusions has not been fully clarified yet, but it is considered as follows. FIG. 2 is a conceptual diagram showing an expected generation mechanism of protrusions. Figure 2
In (a), the locally overheated spot portion 5 of the non-magnetic substrate 4 irradiated with the pulse laser 3 is partially melted and melted by rotating the substrate (the direction is indicated by an arrow) or scanning the laser beam. The part moves. As shown in FIG. 2B, the temperature of the portion where the beam first hits then decreases and a temperature gradient occurs. Generally, in the molten liquid, the surface tension is higher on the low temperature side, and due to this difference in surface tension, the part that was first irradiated with the beam and melted and then became low temperature,
Later, the liquid in the melted part is taken in and rises. Therefore, as shown in FIG. 2C, a concave portion is formed in the last melted portion, and the concave portion is provided at the rear portion of the protrusion in the scanning direction of the laser beam. That is, the vertical cross-sectional shape that passes through the center of the protrusion and includes the scanning direction of the laser beam has a concave portion on one side of the bottom portion of the protrusion. In the present invention, the scanning direction of the laser beam is not only the direction in which the laser beam scans on a stationary disk,
The laser beam is kept stationary, and the rotation direction of the disk when the disk is irradiated with the disk rotated is also shown.
【００１３】レーザビームの走査あるいは基板の回転が
遅いか、あるいはレーザビームのパワーが大きい等の条
件によっては、熱収縮により突起底部の周囲に凹部がで
きる場合もある。この現象の解明は十分ではないが、局
所的に加熱されたスポット部は膨張するが、その回りは
冷えていて変形しにくいため、膨張した部分は外気です
ぐに冷やされ突起として残る。そして突起の周囲は、熱
収縮による凹みができる。また、突起の頂部は平坦では
なく、適度な曲率を有する半球状である。Depending on the conditions such as slow scanning of the laser beam or rotation of the substrate, or high power of the laser beam, there may be a case where a recess is formed around the bottom of the protrusion due to thermal contraction. Although this phenomenon has not been fully clarified, the locally heated spot portion expands, but the surrounding area is cold and difficult to deform, so the expanded portion is immediately cooled by the outside air and remains as a protrusion. Around the protrusion, a recess is formed due to heat shrinkage. Further, the tops of the protrusions are not flat but hemispherical with an appropriate curvature.
【００１４】米国特許第５，０６２，０２１号、同５，
１０８，７８１号記載の方法においては、基板上のＮｉ
Ｐ層の表面にレーザービームを照射しているが、その照
射範囲が広く、かつレーザの出力も１．５Ｗ等の大出力
であるため、ＮｉＰの溶融範囲が広く、溶融した液面の
中心部が盛り上がらずにクレータ状となってしまう。こ
れに対し、本発明においては、レーザビームを狭い範囲
に絞り、出力も低い条件下で精度良く突起を制御するた
め、Ｓｉ等の非磁性基板の溶融範囲が狭く、溶融した液
面の中心部が凸状に盛り上がり、固化した後に突起とな
る点で前記米国特許とは大きく異なる。したがって、先
端の面積も非常に小さな突起ができる。US Pat. Nos. 5,062,021 and 5,5
In the method described in No. 108,781, Ni on the substrate is
The surface of the P layer is irradiated with a laser beam, but the irradiation range is wide and the laser output is a large output such as 1.5 W, so the melting range of NiP is wide and the center of the melted liquid surface is large. Does not rise and becomes a crater. On the other hand, in the present invention, since the laser beam is narrowed to a narrow range and the protrusions are accurately controlled under conditions where the output is low, the melting range of the non-magnetic substrate such as Si is narrow, and the central portion of the melted liquid surface is Differs greatly from the above-mentioned US patent in that it becomes a convex shape and becomes a protrusion after solidification. Therefore, a protrusion having a very small tip area can be formed.
【００１５】また、突起高さはレーザの強度とその平均
照射時間、及びディスクの線速度を調節することによっ
て自由に制御され、突起の密度は、１周当たりの突起の
個数、パルスレーザの半径方向の照射間隔、及び上記の
突起の高さを制御する条件を調節することにより自由に
制御させる。通常、レーザの強度は２０〜５００ｍＷ、
平均照射時間は０．０５〜１００μｓｅｃ、レーザのス
ポット径は０．２〜４μｍ、基板の線速度は０．８〜１
５ｍ／ｓｅｃが好ましい。ここで、レーザの平均照射時
間とは、１つの突起を形成させるのにレーザを下地層表
面に照射した時間を示す。レーザビームの照射面積を変
えるには、通常、対物レンズの開口率を変えればよく、
開口率が０．１〜０．９５の対物レンズを用いることに
より、ビームの照射径は０．７〜６μｍ程度まで制御で
きる。The height of the protrusions can be freely controlled by adjusting the intensity of the laser, the average irradiation time thereof, and the linear velocity of the disk, and the density of the protrusions can be determined by the number of protrusions per revolution and the radius of the pulse laser. The irradiation interval in the direction and the condition for controlling the height of the protrusions are adjusted to freely control. Usually the laser intensity is 20-500 mW,
Average irradiation time is 0.05 to 100 μsec, laser spot diameter is 0.2 to 4 μm, and substrate linear velocity is 0.8 to 1
5 m / sec is preferable. Here, the average irradiation time of the laser refers to the time during which the surface of the underlayer is irradiated with the laser to form one protrusion. To change the irradiation area of the laser beam, it is usually necessary to change the aperture ratio of the objective lens.
By using an objective lens having an aperture ratio of 0.1 to 0.95, the beam irradiation diameter can be controlled to about 0.7 to 6 μm.
【００１６】本発明において、非磁性基板としてはＳｉ
又はアルミニウム合金板等が好ましく用いられるが、
銅、チタン等の金属基板、セラミック基板又は樹脂基板
等を用いることもできる。非磁性基板の材質は、エネル
ギービーム照射による発熱と熱伝導による放熱の関係か
ら、基板表面の反射率が小さく、また、熱拡散率小さな
ものが望ましい。In the present invention, Si is used as the non-magnetic substrate.
Alternatively, an aluminum alloy plate or the like is preferably used,
A metal substrate of copper, titanium, or the like, a ceramic substrate, a resin substrate, or the like can also be used. It is desirable that the material of the non-magnetic substrate has a small reflectance on the substrate surface and a small thermal diffusivity because of the relationship between heat generation by energy beam irradiation and heat dissipation by heat conduction.
【００１７】本発明においては、非磁性基板上に少なく
とも磁性層を有するが、非磁性基板と磁性層の間に下地
層を設けることもできる。下地層は、好ましくはＮｉＰ
合金層であり、通常無電解メッキ法またはスパッタ法に
より形成される。またその厚みは、好ましくは５０〜２
０，０００ｎｍ、特に好ましくは１００〜１５，０００
ｎｍである。In the present invention, at least the magnetic layer is provided on the nonmagnetic substrate, but an underlayer may be provided between the nonmagnetic substrate and the magnetic layer. The underlayer is preferably NiP
An alloy layer, which is usually formed by electroless plating or sputtering. The thickness is preferably 50 to 2
10,000 nm, particularly preferably 100 to 15,000
nm.
【００１８】下地層の上にはＣｒ層、あるいはＣｕ層等
の中間層を磁性層との間に設けるのが好ましく、その膜
厚は通常２０〜２００ｎｍ、好ましくは５０〜１００ｎ
ｍである。下地層上または中間層上に設ける磁性層は、
無電解メッキ、電気メッキ、スパッタ、蒸着等の方法に
よって形成され、Ｃｏ−Ｐ、Ｃｏ−Ｎｉ−Ｐ、Ｃｏ−Ｎ
ｉ−Ｃｒ、Ｃｏ−Ｎｉ−Ｐｔ、Ｃｏ−Ｃｒ−Ｔａ、Ｃｏ
−Ｃｒ−Ｐｔ、Ｃｏ−Ｃｒ−Ｔａ−Ｐｔ系合金等の強磁
性合金薄膜が形成され、その膜厚は通常３０から７０ｎ
ｍ程度である。An intermediate layer such as a Cr layer or a Cu layer is preferably provided on the underlayer between the magnetic layer and the intermediate layer, and the thickness thereof is usually 20 to 200 nm, preferably 50 to 100 n.
m. The magnetic layer provided on the underlayer or the intermediate layer is
It is formed by a method such as electroless plating, electroplating, sputtering or vapor deposition, and is made of Co-P, Co-Ni-P, Co-N.
i-Cr, Co-Ni-Pt, Co-Cr-Ta, Co
A ferromagnetic alloy thin film such as a -Cr-Pt or Co-Cr-Ta-Pt-based alloy is formed, and its film thickness is usually 30 to 70 n.
m.
【００１９】この磁性層上には保護層を設けることがで
きるが、保護層としては蒸着、スパッタ、プラズマＣＶ
Ｄ、イオンプレーティング、湿式法等の方法により、炭
素膜、水素化カーボン膜、ＴｉＣ、ＳｉＣ等の炭化物
膜、ＳｉＮ、ＴｉＮ等の窒化膜等、ＳｉＯ、ＡｌＯ、Ｚ
ｒＯ等の酸化物膜等が成膜される。これらのうち特に好
ましくは、炭素膜、水素化カーボン膜である。又、保護
層上には通常、潤滑剤層が設けられる。A protective layer may be provided on this magnetic layer, and the protective layer is formed by vapor deposition, sputtering or plasma CV.
A carbon film, a hydrogenated carbon film, a carbide film such as TiC and SiC, a nitride film such as SiN and TiN, SiO, AlO, and Z by a method such as D, ion plating, or a wet method.
An oxide film such as rO is formed. Of these, a carbon film and a hydrogenated carbon film are particularly preferable. A lubricant layer is usually provided on the protective layer.
【００２０】[0020]
【実施例】次に、実施例により本発明を更に具体的に説
明するが、本発明はその要旨を超えない限り以下の実施
例によって限定されるものではない。 実施例１〜５、比較例１〜６ 直径６４ｍｍの表面粗さＲａが０．３ｎｍ以下のミラー
ウェハー状Ｓｉディスク基板上に、表−１に記載した条
件に精度良く制御された波長λ＝５１４．５ｎｍのアル
ゴンパルスレーザを照射してほぼ同じ高さの突起を形成
させ、磁気ディスク用基板を得た。EXAMPLES Next, the present invention will be described more specifically by way of examples, but the present invention is not limited to the following examples unless it exceeds the gist. Examples 1 to 5 and Comparative Examples 1 to 6 On a mirror wafer-shaped Si disk substrate having a diameter of 64 mm and a surface roughness Ra of 0.3 nm or less, a wavelength λ = 514 controlled accurately under the conditions shown in Table-1. A magnetic disk substrate was obtained by irradiating a 0.5 nm argon pulse laser to form protrusions having substantially the same height.
【００２１】図１（ａ）は、実施例と同様の方法により
得られたＳｉ基板の表面形状を、レーザ干渉による表面
形状測定装置（米国ザイゴ社製「ＺＹＧＯ」）で観察し
た結果を表す図である。図１（ｂ）は、図１（ａ）の突
起のレーザの走査方向を含む垂直断面図であり、図１
（ｃ）は、突起の中心を通り、図（ｂ）の垂直な方向の
断面図であり、１は突起、２は凹部であり、図１（ｂ）
の２はレーザビームの走査方向に対して突起の後ろ側の
凹部を示す。本発明の突起は図１（ａ）〜（ｃ）および
図２（ｃ）に示すような形状を示し、その孤立した突起
の頂部は平坦ではなく適度な曲率を有する半球状をして
いる。次いで、スパッタ法により、突起を形成させたＳ
ｉ基板上に、順次、ＮｉＰ下地層（１００ｎｍ）、Ｃｒ
中間層（１００ｎｍ）、Ｃｏ−Ｃｒ−Ｔａ合金磁性膜
（５０ｎｍ）及びカーボン保護膜を（２０ｎｍ）を形成
し、その後、浸漬法によりフッ素系液体潤滑剤（モンテ
エジソン社製商品名ＤＯＬ−２０００）を２ｎｍ塗布し
て、磁気記録媒体を作製した。表−１に実施例１〜５お
よび比較例２〜５の基板の線速度、レーザの強度、レー
ザの平均照射時間、平均突起密度（レーザ照射のインタ
ーバルに相当）、平均突起高さ、等高線面積および、レ
ーザの集光に用いた対物レンズの開口率ＮＡを示す。エ
ネルギーの８４％が集中するスポット径は、１．２２×
λ／ＮＡで表される。FIG. 1 (a) is a diagram showing the results of observing the surface shape of a Si substrate obtained by the same method as that of the embodiment with a surface shape measuring apparatus by laser interference ("ZYGO" manufactured by Zygo, USA). Is. FIG. 1B is a vertical cross-sectional view including the laser scanning direction of the protrusion of FIG.
FIG. 1C is a cross-sectional view taken through the center of the protrusion in the direction perpendicular to FIG. 1B, where 1 is a protrusion and 2 is a recess, and FIG.
Reference numeral 2 denotes a concave portion on the rear side of the protrusion with respect to the scanning direction of the laser beam. The projection of the present invention has a shape as shown in FIGS. 1 (a) to 1 (c) and FIG. 2 (c), and the top of the isolated projection is not flat but hemispherical with a proper curvature. Then, S with projections formed by sputtering method
NiP underlayer (100 nm), Cr on i substrate
An intermediate layer (100 nm), a Co-Cr-Ta alloy magnetic film (50 nm) and a carbon protective film (20 nm) are formed, and then a fluorine-based liquid lubricant (trade name DOL-2000 manufactured by Monte Edison Co., Ltd.) is prepared by an immersion method. 2 nm was applied to prepare a magnetic recording medium. Table 1 shows the linear velocities of the substrates of Examples 1 to 5 and Comparative Examples 2 to 5, laser intensity, average laser irradiation time, average protrusion density (corresponding to laser irradiation interval), average protrusion height, contour line area. Also, the numerical aperture NA of the objective lens used for focusing the laser is shown. Spot diameter where 84% of energy is concentrated is 1.22 ×
It is represented by λ / NA.
【００２２】[0022]
【表１】 表−１ ─────────────────────────────────── 基板 レーザ 平均 平均 平均 等高線 対物 線速度 強度 照射時間 突起密度 突起高さ 面積 レンズ (mm/sec) (mW) (μsec)（個／mm2) (nm) (μｍ2) 開口率 ─────────────────────────────────── 実施例１ 343 1750 1.25 9260 14 0.08 0.6 ２ 343 1820 1.25 9260 13 0.16 0.4 ３ 343 1220 1.25 37040 6 0.12 0.95 ４ 343 1990 1.25 4120 16 0.18 0.3 ５ 343 1750 1.25 740 14 0.08 0.6 比較例１ レーザ照射無し ２ 343 940 1.25 9260 <1 ─── 0.95 ３ 343 2800 1.25 9260 66 0.12 0.95 ４ 343 2430 1.25 9260 14 2.30 0.13 ５ 343 945 1.25 93 3 0.12 0.95 ６ 機械的テキスチャ ───────────────────────────────────[Table 1] Table-1 ─────────────────────────────────── Substrate Laser Average Average Average Contour line Objective line Velocity Intensity Irradiation time Protrusion density Protrusion height Area area Lens (mm / sec) (mW) (μsec) (pieces / mm 2 ) (nm) (μm 2 ) Aperture ratio ─────────────── ────────────────────── Example 1 343 1750 1.25 9260 14 0.08 0.6 2 343 1820 1.25 9260 13 0.16 0.4 3 3 343 1220 1.25 37040 6 0.12 0.95 4 343 1990 1.25 4120 16 0.18 0.3 5 343 1750 1.25 740 14 0.08 0.6 Comparative Example 1 No laser irradiation 2 343 940 1.25 9260 <1 ─── 0.95 3 343 2800 1.25 9260 66 0.12 0.95 4 343 2430 1.25 9260 14 2.30 0.13 5 343 945 945 1.25 93 3 0.12 0.95 6 Mechanical texture ────────────────────────────────────
【００２３】また、比較例６は従来の機械的テキスチャ
法で、Ｒａが約２ｎｍの粗さのテキスチャを施したＡｌ
合金基板を用いた。各々、スパッタ以降は実施例１〜５
と同様のプロセスで作製した。表−２にこれらのディス
クのＣＳＳテスト前の静止摩擦係数（初期スティクショ
ン）及びＣＳＳ２万回後の摩擦力を示した。ＣＳＳテス
トはヘッド浮上量１．６μインチ、ロードグラム６ｇｆ
の薄膜ヘッド（スライダ材質Ａｌ2Ｏ3ＴｉＣ）を用い
た。ヘッドの安定浮上高さは、データゾーンとＣＳＳゾ
ーン間のシーク時のヘッドの安定浮上性をグライドテス
ターを用いて評価した。ＣＳＳゾーンの安定浮上高さ
は、実施例３は０．８μインチ以下、比較例３は２μイ
ンチ以上、比較例６は１〜１．２μインチ、それ以外の
例においてはすべて０．８μインチであった。Further, Comparative Example 6 is a conventional mechanical texture method, in which Ra is a textured Al having a roughness of about 2 nm.
An alloy substrate was used. Examples 1 to 5 after sputtering
It was manufactured by the same process as. Table 2 shows the coefficient of static friction (initial stiction) before CSS test and the friction force after CSS 20,000 times of these disks. The CSS test is a head flying height of 1.6μ inch and a loadgram of 6gf.
Thin film head (slider material Al 2 O 3 TiC) was used. The stable flying height of the head was evaluated by using a glide tester to evaluate the stable flying ability of the head when seeking between the data zone and the CSS zone. The stable flying height of the CSS zone is 0.8 μ inch or less in Example 3, 2 μ inch or more in Comparative Example 3, 1 to 1.2 μ inch in Comparative Example 6, and 0.8 μ inch in all other examples. there were.
【００２４】[0024]
【表２】 表−２ ─────────────────────────────────── 初期スティクション ＣＳＳ２万回後の （摩擦係数） 摩擦力 ─────────────────────────────────── 実施例１ ０．１４ ３ｇｆ ２ ０．１７ ７ｇｆ ３ ０．２３ ６ｇｆ ４ ０．４３ １２ｇｆ ５ ０．６４ １４ｇｆ 比較例１ 測定不能（吸着によりヘッドクラッシュ） ２ ６．２２ 吸着ドライブ停止（８００回） ３ ０．１６ ヘッドクラッシュ（９００回） ４ １．３１ ２５ｇｆ ５ １．３５ ３３ｇｆ ６ ０．７８ ２８ｇｆ ───────────────────────────────────[Table 2] Table-2 ─────────────────────────────────── Initial stiction CSS after 20,000 times (Frictional coefficient) Friction force ─────────────────────────────────── Example 1 0.14 3gf 20 .17 7gf 3 0.23 6gf 4 0.43 12gf 5 0.64 14gf Comparative Example 1 Unmeasurable (head crash due to adsorption) 2 6.22 Adsorption drive stop (800 times) 3 0.16 Head crash (900 times) 4 1.31 25gf 5 1.35 33gf 6 0.78 28gf ────────────────────────────────────
【００２５】[0025]
【発明の効果】本発明においては、非磁性基板の磁性層
側表面に、突起の高さとその先端の形状、突起の存在領
域および密度が制御された表面形状を形成するため、磁
気ヘッド下面と磁気記録媒体の表面との接触面積が少な
く、ＣＳＳ時の摩擦が極端に小さくなり、また、ヘッド
の媒体表面へのスティキングも全く発生しなくなる。ま
た、ヘッドのＣＳＳゾーンのみにこうした突起を作った
場合、平均的な面の高さはほとんど変わらないため、ヘ
ッドをデータゾーン及びＣＳＳゾーン間でシークした時
にヘッドの安定浮上高さの変動が少なく、ヘッドクラッ
シュやヘッドの空間での不安定化が起こらない。更に、
この突起の高さや密度をデータゾーンに近づくにしたが
って制御することもできるため、ヘッドのデータゾーン
及びＣＳＳゾーン間でのシークは極めて滑らかに行なう
ことができる。この場合データゾーンでは、従来のよう
な機械的テキスチャによる表面の傷を作る必要がないの
で、ヘッドの浮上安定高さを小さくでき、また、前記ス
クラッチ傷によるデータのエラーも減少するため高密度
の磁気記録媒体の製造が可能となり、工業的な意義は極
めて大きい。According to the present invention, the surface of the non-magnetic substrate on the side of the magnetic layer is formed with a surface shape in which the height of the protrusion and the shape of the tip, the region where the protrusion is present, and the density are controlled. The contact area with the surface of the magnetic recording medium is small, friction during CSS becomes extremely small, and sticking of the head to the medium surface does not occur at all. Also, when such protrusions are formed only in the CSS zone of the head, the average surface height hardly changes, so there is little fluctuation in the stable flying height of the head when seeking between the data zone and the CSS zone. No head crash or destabilization of the head space. Furthermore,
Since the height and density of the protrusions can be controlled as they approach the data zone, the seek between the data zone and the CSS zone of the head can be performed extremely smoothly. In this case, in the data zone, it is not necessary to make surface scratches due to mechanical texture as in the conventional case, so that the flying stability height of the head can be made small, and data errors due to the scratches are reduced, so that high density is achieved. A magnetic recording medium can be manufactured, and its industrial significance is extremely large.
【図１】表面形状測定装置により観察した本発明のＳｉ
基板表面の突起の形状を示す図であり、（ａ）は斜視
図、（ｂ）は突起の中心を通りレーザの走査方向を含む
垂直断面図、（ｃ）は突起の中心を通り図１（ｂ）の垂
直な方向の断面図である。FIG. 1 Si of the present invention observed by a surface profile measuring apparatus.
1A is a perspective view showing a shape of a protrusion on a substrate surface, FIG. 1B is a vertical sectional view including a laser scanning direction through a center of the protrusion, and FIG. FIG. 7B is a sectional view in the vertical direction of b).
【図２】本発明の突起の予想される生成機構を示す概念
図である。FIG. 2 is a conceptual diagram showing an expected generation mechanism of protrusions of the present invention.
【図３】従来の方法による媒体表面の形状を示す斜視図
である。FIG. 3 is a perspective view showing a shape of a medium surface according to a conventional method.
１ 突起 ２ 凹部 ３ パルスレーザ ４ 非磁性基板 ５ スポット部 ６ 凹状の穴部 ７ リム部 1 Protrusion 2 Recess 3 Pulse Laser 4 Nonmagnetic Substrate 5 Spot 6 Recessed Hole 7 Rim
フロントページの続き (72)発明者 有田 陽二 神奈川県横浜市緑区鴨志田町1000番地 三 菱化学株式会社横浜総合研究所内Front page continued (72) Inventor Yoji Arita 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Sanryo Chemical Co., Ltd. Yokohama Research Institute
Claims (10)
する磁気記録媒体であって、非磁性基板の磁性層側表面
に、高さが１〜６０ｎｍの突起を１ｍｍ2 あたり１０2
〜１０8 個有し、且つ、各突起の頂点から１ｎｍ下の高
さにおける等高線で囲まれた図形の面積の平均値が２μ
ｍ2 以下であることを特徴とする磁気記録媒体。To 1. A non-magnetic substrate, a magnetic recording a medium, the magnetic layer-side surface of the non-magnetic substrate, 1 mm 2 per 10 2 height projections of 1~60nm having at least a magnetic layer
10 has eight, and the average value 2μ area of a figure enclosed by contour line at height below 1nm from the apex of each projection
A magnetic recording medium characterized by being m 2 or less.
を特徴とする請求項１に記載の磁気記録媒体。2. The magnetic recording medium according to claim 1, wherein the protrusion has a recess around the bottom thereof.
トアンドストップ）を行なう領域のみに突起が存在する
ことを特徴とする請求項１又は２に記載の磁気記録媒
体。3. The magnetic recording medium according to claim 1, wherein the protrusion is present only in a region where the magnetic head performs CSS (contact start and stop).
減少していることを特徴とする請求項３に記載の磁気記
録媒体。4. The magnetic recording medium according to claim 3, wherein the height of the protrusion decreases toward the data recording area.
していることを特徴とする請求項３又は４に記載の磁気
記録媒体。5. The magnetic recording medium according to claim 3, wherein the density of the protrusions decreases toward the data area.
成されてなることを特徴とする請求項１〜５に記載の磁
気記録媒体。6. The magnetic recording medium according to claim 1, wherein the projection is formed by irradiation with an energy beam.
走査方向を含む垂直断面形状が、突起底部の片側部分に
凹部を有することを特徴とする請求項６に記載の磁気記
録媒体。7. The magnetic recording medium according to claim 6, wherein the vertical cross-sectional shape passing through the center of the protrusion and including the scanning direction of the energy beam has a recess on one side of the bottom of the protrusion.
する磁気記録媒体用基板であって、非磁性基板の磁性層
側表面に、高さが１〜６０ｎｍの突起を１ｍｍ2 あたり
１０2 〜１０8 個有し、且つ、各突起の頂点から１ｎｍ
下の高さにおける等高線で囲まれた図形の面積の平均値
が２μｍ2 以下であることを特徴とする磁気記録媒体用
基板。8. A substrate for a magnetic recording medium having at least a magnetic layer on a non-magnetic substrate, wherein projections having a height of 1 to 60 nm are formed on the surface of the non-magnetic substrate at the magnetic layer side of 10 2 to 1 2 per mm 2. 10 8 pieces, and 1 nm from the top of each protrusion
A substrate for a magnetic recording medium, wherein the average value of the area surrounded by contour lines at the lower height is 2 μm 2 or less.
成されてなることを特徴とする請求項８に記載の磁気記
録媒体用基板。9. The substrate for a magnetic recording medium according to claim 8, wherein the protrusion is formed by irradiation with an energy beam.
の走査方向を含む垂直断面形状が、突起底部の片側部分
に凹部を有することを特徴とする請求項９に記載の磁気
記録媒体用基板。10. The substrate for a magnetic recording medium according to claim 9, wherein the vertical cross-sectional shape passing through the center of the protrusion and including the scanning direction of the energy beam has a recess on one side of the bottom of the protrusion.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6241369A JP3013717B2 (en) | 1994-10-05 | 1994-10-05 | Magnetic recording medium and substrate |
| DE19524220A DE19524220A1 (en) | 1994-07-04 | 1995-07-03 | Magnetic recording medium allowing head suspension distance to be reduced for hard disc scanning |
| KR1019950019855A KR960005459A (en) | 1994-07-04 | 1995-07-03 | Magnetic recording medium, manufacturing method thereof, and recording and reading method |
| US08/937,045 US5928759A (en) | 1994-07-04 | 1997-09-24 | Magnetic recording medium, method of producing the same, and recording and reading-out method |
| US09/306,909 US6217970B1 (en) | 1994-07-04 | 1999-05-07 | Magnetic recording medium, method of producing the same, and recording and reading-out method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6241369A JP3013717B2 (en) | 1994-10-05 | 1994-10-05 | Magnetic recording medium and substrate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08106630A true JPH08106630A (en) | 1996-04-23 |
| JP3013717B2 JP3013717B2 (en) | 2000-02-28 |
Family
ID=17073270
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6241369A Expired - Fee Related JP3013717B2 (en) | 1994-07-04 | 1994-10-05 | Magnetic recording medium and substrate |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3013717B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5595768A (en) * | 1995-11-02 | 1997-01-21 | Komag, Incorporated | Laser disk texturing apparatus |
| US5948288A (en) * | 1996-05-28 | 1999-09-07 | Komag, Incorporated | Laser disk texturing apparatus |
| US5978189A (en) * | 1996-07-31 | 1999-11-02 | Asahi Komag Co., Ltd. | Substrate for a magnetic recording medium having laser beam absorption characteristic and a magnetic recording medium using the substrate |
-
1994
- 1994-10-05 JP JP6241369A patent/JP3013717B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5595768A (en) * | 1995-11-02 | 1997-01-21 | Komag, Incorporated | Laser disk texturing apparatus |
| US5948288A (en) * | 1996-05-28 | 1999-09-07 | Komag, Incorporated | Laser disk texturing apparatus |
| US5978189A (en) * | 1996-07-31 | 1999-11-02 | Asahi Komag Co., Ltd. | Substrate for a magnetic recording medium having laser beam absorption characteristic and a magnetic recording medium using the substrate |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3013717B2 (en) | 2000-02-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6217970B1 (en) | Magnetic recording medium, method of producing the same, and recording and reading-out method | |
| US6057984A (en) | Method for data writing/read-out using a contact start and stop system | |
| JP3013717B2 (en) | Magnetic recording medium and substrate | |
| JPH0877554A (en) | Magnetic recording medium and substrate | |
| JP2953364B2 (en) | Magnetic recording medium and substrate | |
| JP2970466B2 (en) | Manufacturing method of magnetic recording medium | |
| JP2856131B2 (en) | Method for forming protrusions on magnetic recording medium and magnetic recording medium | |
| JP3146917B2 (en) | Manufacturing method of magnetic recording medium | |
| JP3629275B2 (en) | Method for forming texture in magnetic recording medium by laser irradiation using multiple lens focusing | |
| JPH08129749A (en) | Magnetic recording medium and substrate | |
| JPH08147692A (en) | Manufacture of magnetic recording medium | |
| JPH08147687A (en) | Magnetic recording medium and its manufacture | |
| JPH08147684A (en) | Magnetic recording medium and substrate | |
| US5945197A (en) | Laser texturing of magnetic recording medium using multiple lens focusing | |
| JPH08180400A (en) | Magnetic recording medium and substrate | |
| JPH08147682A (en) | Magnetic disk and substrate for magnetic disk and recording and reproduction method | |
| JPH10222841A (en) | Magnetic recording medium and substrate | |
| JPH1186279A (en) | Magnetic recording medium and substrate | |
| JPH09180180A (en) | Magnetic disk | |
| JPH09180179A (en) | Magnetic recording medium and its production | |
| JPH08153325A (en) | Magnetic recording medium and substrate | |
| JPH08287457A (en) | Production of magnetic recording medium | |
| JP2001067660A (en) | Production of magnetic recording medium | |
| JPH09231562A (en) | Magnetic recording medium and its production | |
| JPH08147916A (en) | Recording and reproducing method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20081217 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Year of fee payment: 10 Free format text: PAYMENT UNTIL: 20091217 |
|
| LAPS | Cancellation because of no payment of annual fees |