JP3133443B2 - Magneto-optical recording medium - Google Patents
Magneto-optical recording mediumInfo
- Publication number
- JP3133443B2 JP3133443B2 JP03359982A JP35998291A JP3133443B2 JP 3133443 B2 JP3133443 B2 JP 3133443B2 JP 03359982 A JP03359982 A JP 03359982A JP 35998291 A JP35998291 A JP 35998291A JP 3133443 B2 JP3133443 B2 JP 3133443B2
- Authority
- JP
- Japan
- Prior art keywords
- magneto
- recording medium
- film
- optical recording
- underlayer
- 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 - Fee Related
Links
Description
【0001】[0001]
【産業上の利用分野】本発明は、書換え可能な光磁気記
録媒体に関する。詳しくは、数〜数十原子層の白金族の
金属と、数原子層の遷移金属とが交互に積層された交互
積層膜を、透光性の下地層を介して基板上に成膜して成
る光磁気記録媒体に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rewritable magneto-optical recording medium. Specifically, an alternately laminated film in which several to several tens of atomic layers of a platinum group metal and several atomic layers of transition metals are alternately stacked is formed on a substrate via a light-transmitting underlayer. A magneto-optical recording medium comprising:
【0002】[0002]
【従来の技術】繰り返して記録・再生の可能な光磁気記
録媒体用の記録膜(垂直磁化膜)として、PtとCoを
交互に積層して成る交互積層膜が提案されている。これ
は、Pt/Coの交互積層膜の短波長領域での感度が良
好であり、高密度記録媒体として有望なためである(Di
electric enhancement layers for a Pt/Co multilayer
magneto-optical recording medium ; Applied Physics
Letters 58 , 191(1991)) 。なお、上記交互積層膜の
総膜厚は、数百Å以下の超薄膜領域にある。2. Description of the Related Art As a recording film (perpendicular magnetization film) for a magneto-optical recording medium which can be repeatedly recorded / reproduced, an alternately laminated film comprising Pt and Co alternately laminated has been proposed. This is because the Pt / Co alternately laminated film has good sensitivity in a short wavelength region and is promising as a high-density recording medium (Di
electric enhancement layers for a Pt / Co multilayer
magneto-optical recording medium; Applied Physics
Letters 58, 191 (1991)). The total thickness of the alternately stacked films is in an ultrathin region of several hundreds of square meters or less.
【0003】また、上記の交互積層膜と基板との間に、
カ−効果を増大させるために、アモルファスのSiN等
の誘電体膜を下地層として成膜したものもあり、その表
面には、平滑化のために、エッチング処理が施されてい
る(第14回日本応用磁気学会講演概要集P65)。[0003] Further, between the above-mentioned alternately laminated film and the substrate,
In order to increase the Kerr effect, there is also a film in which a dielectric film such as amorphous SiN is formed as a base layer, and the surface thereof is subjected to an etching process for smoothing (14th. Proceedings of the Japanese Society of Applied Magnetics P65).
【0004】[0004]
【発明が解決しようとする課題】基板上にSiN等の誘
電体膜を下地層として形成し、その上に、Pt/Coの
交互積層膜から成る垂直磁化膜を成膜する上記の構成で
は、SiNがアモルファス状態である。このため、該S
iN膜の上に形成されるPt層も、当初は〔111〕方
向に綺麗に積層されず、垂直磁気異方性が小さい。した
がって、高密度記録に必要な保磁力も、1〔kOe〕程
度と、それほど大きくない。In the above-described structure, a dielectric film such as SiN is formed as a base layer on a substrate, and a perpendicular magnetization film formed of an alternately laminated Pt / Co film is formed thereon. SiN is in an amorphous state. Therefore, the S
At first, the Pt layer formed on the iN film is not well laminated in the [111] direction, and has a small perpendicular magnetic anisotropy. Therefore, the coercive force required for high-density recording is not so large, about 1 kOe.
【0005】本出願人は、上記の問題に鑑み、先に、下
地層としてZnO等を用いた光磁気記録媒体を考案し
て、出願している(平成3年特許願第126087号)。上記
出願の光磁気記録媒体では、下地層が、〔111〕方向
から見たPtと同様に、密に並ぶ。このため、下地層の
上に形成されるPt層も〔111〕方向に並び易く、高
密度記録に必要な保磁力も、アモルファスのSiNの下
地層を用いる従来の場合より向上している。In view of the above problems, the present applicant has previously devised and applied for a magneto-optical recording medium using ZnO or the like as an underlayer (Japanese Patent Application No. 126087, 1991). In the magneto-optical recording medium of the above application, the underlayers are densely arranged like Pt viewed from the [111] direction. For this reason, the Pt layers formed on the underlayer are easily arranged in the [111] direction, and the coercive force required for high-density recording is improved as compared with the conventional case using the amorphous SiN underlayer.
【0006】本発明は、上記出願(平成3年特許願第12
6087号)の延長上にある。即ち、白金族の金属と遷移金
属との交互積層膜を透光性の下地層を介して基板上に成
膜して成る光磁気記録媒体について、下地層の結晶粒径
が垂直磁化膜の膜特性に影響することを見出し、その関
係に着目することによって、特性の良い光磁気記録媒体
を得ることを目的とする。[0006] The present invention relates to the above-mentioned application (patent application No. 12 of 1991).
No. 6087). That is, in a magneto-optical recording medium in which an alternately laminated film of a platinum group metal and a transition metal is formed on a substrate via a light-transmitting underlayer, the crystal grain size of the underlayer is a film of a perpendicular magnetization film. It is an object of the present invention to obtain a magneto-optical recording medium having good characteristics by finding that the characteristics affect the characteristics and paying attention to the relationship.
【0007】[0007]
【課題を解決するための手段】本発明は、白金族の金属
層と遷移金属層とが交互に積層された超薄膜の交互積層
膜を、透光性の下地層を介して基板上に成膜して成る光
磁気記録媒体に於いて、前記透光性下地層は、ZnOか
ら成り、且つ100〜1000Åの範囲の結晶粒径を有
し、さらに前記白金族の金属層が〔111〕方向に配向
するような結晶構造を有することを特徴とする光磁気記
録媒体である。According to the present invention, an ultra-thin alternately laminated film in which platinum group metal layers and transition metal layers are alternately laminated is formed on a substrate via a light-transmitting underlayer. In a magneto-optical recording medium comprising a film, the light- transmitting underlayer may be made of ZnO or
The platinum group metal layer is oriented in the [111] direction.
A magneto-optical recording medium characterized by having a crystal structure as follows.
【0008】上記に於いて、結晶粒径を100〜100
0Åの範囲に制御するためには、成膜時に、基板温度,
スパッタレ−ト,スパッタガス圧力等のパラメ−タを妥
当な値に制御すればよい。また、白金族の金属としては
Pt,Pd,PtPd,PtNi,PtFe,PtCo
から選ばれる金属を、遷移金属としてはCo,Fe,N
i,FeCo,CoNiから選ばれる金属を、それぞれ
用いることができる。[0008] In the above, the crystal grain size is 100-100
In order to control the temperature within the range of 0 °, the substrate temperature,
The parameters such as sputter rate and sputter gas pressure may be controlled to appropriate values. Pt, Pd, PtPd, PtNi, PtFe, PtCo are platinum group metals.
And transition metals such as Co, Fe, N
A metal selected from i, FeCo, and CoNi can be used.
【0009】なお、本発明の光磁気記録媒体に、従来の
他の構成、例えば、保護膜としての誘電体層、或いは、
多重反射によりカ−効果にファラデ−効果を相乗させる
ための反射層等、従来の他の構成を付加してもよいこと
は、従来と同様である。さらに、基板としても、従来と
同様に、ガラス、ポリカ−ボネ−ト(PC)、ポリメチ
ルメタクリレ−ト、エポキシ樹脂等を用いることができ
る。The magneto-optical recording medium of the present invention has another conventional structure, for example, a dielectric layer as a protective film, or
As in the conventional case, another structure such as a reflective layer for adding the Faraday effect to the Carr effect by multiple reflection may be added. Further, as the substrate, glass, polycarbonate (PC), polymethyl methacrylate, epoxy resin or the like can be used as in the conventional case.
【0010】[0010]
【作用】ZnOから成る透光性の下地層の成膜時、その
結晶粒径が100〜1000Åの範囲となるように、基
板温度等の成膜条件が制御される。次に、上記のように
成膜された下地層の上に、Pt/Co等の超薄膜の交互
積層膜が成膜される。該交互積層膜は、上記の下地層の
結晶方位に従い、且つ、略同程度の結晶粒径で、膜厚方
向にコラム状に成長する。即ち、交互積層膜の膜構造
は、下地層の結晶粒径によって制御される。When forming a light-transmitting underlayer made of ZnO, the film-forming conditions such as the substrate temperature are controlled so that the crystal grain size is in the range of 100 to 1000 °. Next, on the base layer formed as described above, an alternate thin film of an ultrathin film such as Pt / Co is formed. The alternate layered film grows in a columnar shape in the thickness direction according to the crystal orientation of the underlayer and with substantially the same crystal grain size. That is, the film structure of the alternately stacked film is controlled by the crystal grain size of the underlying layer.
【0011】[0011]
【実施例】以下、本発明の実施例を説明する。図1は実
施例の光磁気ディスクの断面の一部を模式的に示し、図
2は上記光磁気ディスクの作成に用いるスパッタリング
装置の構成を示す。また、図3及び図4は、実施例の光
磁気ディスクの特性を示すグラフである。Embodiments of the present invention will be described below. FIG. 1 schematically shows a part of a cross section of the magneto-optical disk of the embodiment, and FIG. 2 shows a structure of a sputtering apparatus used for producing the magneto-optical disk. FIGS. 3 and 4 are graphs showing characteristics of the magneto-optical disk of the example.
【0012】図示の光磁気ディスクは、プリグル−ブ付
のポリカ−ボネ−ト(PC)基板3の表面に、ZnOの
下地層1を1000〔Å〕の厚さに成膜し、その上に、Pt
とCoとを交互に、合計9層に成膜して、交互積層膜2
としたものである。なお、各層について、Pt=17
〔Å〕,Co=5 〔Å〕の厚さとした。下地層1の成膜
は、図2に示す装置を用い、反応性スパッタリングによ
って行った。成膜条件は、タ−ゲットをZnOとし、ガ
スとしてAr+O2 を用い、混合ガスの圧力比をAr:
O2 =1:0.2、投入電力を500〔W〕とした。ま
た、結晶粒径の制御は、全ガス圧を調整することにより
行った。In the illustrated magneto-optical disk, a ZnO underlayer 1 is formed on the surface of a polycarbonate (PC) substrate 3 with a pregroove to a thickness of 1000 [Å]. , Pt
And Co are alternately formed into a total of 9 layers to form an alternate laminated film 2
It is what it was. Note that, for each layer, Pt = 17
[Å], Co = 5 [Å] thickness. The underlayer 1 was formed by reactive sputtering using the apparatus shown in FIG. The film formation conditions were as follows: the target was ZnO, the gas was Ar + O 2, and the pressure ratio of the mixed gas was Ar:
O 2 = 1: 0.2 and the input power was 500 [W]. The control of the crystal grain size was performed by adjusting the total gas pressure.
【0013】一方、交互積層膜2の成膜は、上記と同じ
装置を用い、スパッタリングによって行った。タ−ゲッ
トを、Pt(6a)、Co(6b)とし、基板ホルダ7を回転さ
せることにより、順次、上記の厚さに積層した。図2に
示す装置は、ポンプPで排気される真空槽4と、該真空
槽4内の上方に回転可能に配設された基板ホルダ7と、
上記真空槽4内を区分する遮蔽板5とを備え、電源より
供給されるRF又はDCの電力により、スパッタリング
を行う装置である。なお、基板ホルダ7の回転速度はモ
−タMにより制御可能であり、また、上記の基板3は、
基板ホルダ7の下面に、回転の軸心から偏心するように
して保持されている。On the other hand, the formation of the alternate laminated film 2 was performed by sputtering using the same apparatus as described above. The targets were Pt (6a) and Co (6b), and the substrate was laminated to the above thickness by rotating the substrate holder 7. The apparatus shown in FIG. 2 includes a vacuum chamber 4 evacuated by a pump P, a substrate holder 7 rotatably disposed above the vacuum chamber 4,
The apparatus includes a shielding plate 5 for partitioning the inside of the vacuum chamber 4 and performs sputtering by RF or DC power supplied from a power supply. The rotation speed of the substrate holder 7 can be controlled by a motor M.
It is held on the lower surface of the substrate holder 7 so as to be eccentric from the axis of rotation.
【0014】また、スパッタリングのタ−ゲットは、真
空槽4内に於いて上記遮蔽板5により区分される各空間
内下方の各保持板6a,6b に各々保持され、また、スパッ
タリングのガスは、ボンベBからバルブ9を介して供給
される。上記の装置により、上記の如く作成した本光磁
気ディスクは、ZnOの下地層1の結晶粒径に関して、
図3及び図4に示す特性を有する。A sputtering target is held in each holding plate 6a, 6b below each space divided by the shielding plate 5 in the vacuum chamber 4, and the sputtering gas is It is supplied from a cylinder B via a valve 9. The magneto-optical disk produced as described above by the above-described apparatus has a crystal grain size of the ZnO underlayer 1 as follows.
It has the characteristics shown in FIGS.
【0015】即ち、垂直磁気異方性エネルギ−は、図3
のように、結晶粒径が大きくなるに従って大きくなる。
これは、交互積層膜2が、成膜の当初から、ZnOの結
晶方位に従って、略同程度の結晶粒径で成長するためで
ある。また、CNR(Carrier to Noise Ratio) は、図
4に示すように、結晶粒径が100 〜1000Åの範囲で大き
く、その範囲を外れると、低下している。これは、結晶
粒径が100 Å以下の範囲では垂直磁気異方性エネルギ−
が小さいため、キャリアの低下とノイズの増大を引起
し、一方、結晶粒径が1000Åを越えると、結晶粒界の光
散乱によってノイズが増大するためである。That is, the perpendicular magnetic anisotropy energy is shown in FIG.
As shown in FIG.
This is because the alternately laminated film 2 grows with substantially the same crystal grain size according to the crystal orientation of ZnO from the beginning of the film formation. Also, as shown in FIG. 4, the CNR (Carrier to Noise Ratio) is large in the range of 100 to 1000 ° in crystal grain size, and falls outside the range. This is because the perpendicular magnetic anisotropy energy is smaller when the grain size is less than 100 mm.
Is small, causing a decrease in carriers and an increase in noise. On the other hand, when the crystal grain size exceeds 1000 °, noise increases due to light scattering at crystal grain boundaries.
【0016】このように、下地層1の結晶粒径が100 〜
1000Åの範囲では、垂直磁気異方性エネルギ−が大き
く、且つ、CNRの大きい光磁気ディスクを得る。即
ち、高密度記録が可能となる。As described above, the crystal grain size of the underlayer 1 is 100 to
In the range of 1000 °, a magneto-optical disk having a large perpendicular magnetic anisotropy energy and a large CNR is obtained. That is, high-density recording becomes possible.
【0017】[0017]
【発明の効果】本発明では、透光性の下地層は、その膜
厚が200〜2000Åの範囲に、結晶粒径が100〜
1000Åの範囲に、それぞれ在る。このため、上記下
地層の上に形成される交互積層膜が、該下地層の結晶方
位に従って、且つ、結晶粒径が略同程度に、膜厚方向に
コラム状に成長する。According to the present invention, the light-transmitting underlayer has a thickness of 200 to 2000 ° and a crystal grain size of 100 to 2000 °.
Each is in the range of 1000 °. For this reason, the alternately laminated film formed on the underlayer grows in a columnar shape in the film thickness direction according to the crystal orientation of the underlayer and with substantially the same crystal grain size.
【0018】これにより、交互積層膜の結晶性及び配向
性が向上して垂直磁気異方性が大きくなり、カ−回転角
も増大し、また、ノイズも低減される。As a result, the crystallinity and orientation of the alternately laminated film are improved, the perpendicular magnetic anisotropy is increased, the car rotation angle is increased, and noise is reduced.
【図1】実施例の光磁気ディスクの断面構造を模式的に
示す説明図である。FIG. 1 is an explanatory view schematically showing a cross-sectional structure of a magneto-optical disk according to an embodiment.
【図2】上記光磁気ディスクを作成するためのスパッタ
リング装置の説明図である。FIG. 2 is an explanatory diagram of a sputtering apparatus for producing the magneto-optical disk.
【図3】上記光磁気ディスクの下地層の結晶粒径と垂直
磁気異方性エネルギ−との関係を示す特性図である。FIG. 3 is a characteristic diagram showing a relationship between a crystal grain size of an underlayer of the magneto-optical disk and perpendicular magnetic anisotropy energy.
【図4】上記光磁気ディスクの下地層の結晶粒径とCN
R(Carrier to Noise Ratio)との関係を示す特性図で
ある。FIG. 4 shows the crystal grain size and CN of the underlayer of the magneto-optical disk.
FIG. 4 is a characteristic diagram showing a relationship with R (Carrier to Noise Ratio).
1 下地層(ZnO) 2 Pt/Co交互積層膜 3 基板 DESCRIPTION OF SYMBOLS 1 Underlayer (ZnO) 2 Pt / Co alternate lamination film 3 Substrate
フロントページの続き (56)参考文献 特開 平4−351733(JP,A) (58)調査した分野(Int.Cl.7,DB名) G11B 11/105 Continuation of the front page (56) References JP-A-4-351733 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) G11B 11/105
Claims (1)
積層された超薄膜の交互積層膜を、透光性の下地層を介
して基板上に成膜して成る光磁気記録媒体に於いて、前記透光性下地層は、ZnOから成り 、且つ100〜1
000Åの範囲の結晶粒径を有し、さらに前記白金族の
金属層が〔111〕方向に配向するような結晶構造を有
することを特徴とする光磁気記録媒体。A magneto-optical recording medium comprising an ultra-thin alternately laminated film in which platinum group metal layers and transition metal layers are alternately laminated on a substrate via a light-transmitting underlayer. In the above, the transparent base layer may be made of ZnO , and
It has a crystal grain size in the range of 000 ° and a crystal structure in which the platinum group metal layer is oriented in the [111] direction.
A magneto-optical recording medium.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP03359982A JP3133443B2 (en) | 1991-12-26 | 1991-12-26 | Magneto-optical recording medium |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP03359982A JP3133443B2 (en) | 1991-12-26 | 1991-12-26 | Magneto-optical recording medium |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH05182262A JPH05182262A (en) | 1993-07-23 |
JP3133443B2 true JP3133443B2 (en) | 2001-02-05 |
Family
ID=18467294
Family Applications (1)
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JP03359982A Expired - Fee Related JP3133443B2 (en) | 1991-12-26 | 1991-12-26 | Magneto-optical recording medium |
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Country | Link |
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JP (1) | JP3133443B2 (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH06139637A (en) * | 1992-10-29 | 1994-05-20 | Canon Inc | Magneto-optical recording medium |
AU2003208093A1 (en) * | 2003-01-31 | 2004-08-23 | Fujitsu Limited | Magnetooptic recording medium and method for producing the same |
JP4647241B2 (en) * | 2003-08-04 | 2011-03-09 | シャープ株式会社 | Optical recording medium master manufacturing method, optical recording medium stamper manufacturing method, and optical recording medium manufacturing method |
-
1991
- 1991-12-26 JP JP03359982A patent/JP3133443B2/en not_active Expired - Fee Related
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JPH05182262A (en) | 1993-07-23 |
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