JPS6243274B2 - - Google Patents
Info
- Publication number
- JPS6243274B2 JPS6243274B2 JP7234780A JP7234780A JPS6243274B2 JP S6243274 B2 JPS6243274 B2 JP S6243274B2 JP 7234780 A JP7234780 A JP 7234780A JP 7234780 A JP7234780 A JP 7234780A JP S6243274 B2 JPS6243274 B2 JP S6243274B2
- Authority
- JP
- Japan
- Prior art keywords
- cylindrical magnetic
- cylindrical
- slot
- magnetic domain
- domain
- 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
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11C—STATIC STORES
- G11C19/00—Digital stores in which the information is moved stepwise, e.g. shift registers
- G11C19/02—Digital stores in which the information is moved stepwise, e.g. shift registers using magnetic elements
- G11C19/08—Digital stores in which the information is moved stepwise, e.g. shift registers using magnetic elements using thin films in plane structure
- G11C19/0808—Digital stores in which the information is moved stepwise, e.g. shift registers using magnetic elements using thin films in plane structure using magnetic domain propagation
- G11C19/0841—Digital stores in which the information is moved stepwise, e.g. shift registers using magnetic elements using thin films in plane structure using magnetic domain propagation using electric current
Description
本発明は二層導体パタン記憶素子における円筒
磁区の初期駆動方式に関するものである。
円筒磁区を情報の担体として用いる記憶素子に
おいて、円筒磁区の転送方式は、パ−マロイの如
き軟磁性膜でできたシエプロン型やＹ−型を呈し
たパタンを外部より印加する面内回転磁界によつ
て順次磁化することによつて生じる磁極にバブル
磁区を引きつけて転送させる、いわゆるフイール
ドアクセス方式が一般的であつた。しかしながら
このフイールドアクセス方式は、記憶密度を大き
くするために円筒磁区径を小さくするに従つて、
円筒磁区転送に必要な面内回転磁界が急激に大き
くなり、消費電力が大きくなるとともに、面内回
転磁界発生用コイルに印加する電圧が増大し、高
速転送に適さなくなるという大きな欠点を持つて
いることはよく知られている。更に、円筒磁区径
が小さくなるにつれて、パーマロイパタン形成に
必要な最小寸法が小さくなり２μｍ以下の円筒磁
区を用いる素子の製造は非常に困難となる。
この様な従来のフイールドアクセス型円筒磁区
素子の欠点を克服するために、電流アクセス型の
二層導体パタン記憶素子がエイ・エイツチ・ボベ
ツク（A.H.Bobeck）によつて1979年８月にサ・
ベル・システム・テクニカル・ジヤーナル（He
Bell Syotem Feohnical Pournal）第58巻、第６
号、第1453頁〜1540頁に発表された。この二層導
体パタン記憶素子の本質は、円筒磁区材料上に設
けられた導体層に短型或いは長円状の貫通穴列を
作り、この導体層に交流電流を通じたときその穴
周辺に生じる電流分布によるバイアス磁界分布を
用いて円筒磁区の駆動を行なうことにある。
二層導体パタン記憶素子では消費電力を低減さ
せるためにできる限り微少の電流で駆動すること
が必要である。周知のように円筒磁区の初期駆動
時は特に転送エラーの起こる確率が高い。
本発明は上記初期転送エラーの確率を低減しか
つできる限り微少な電流で円筒磁区駆動すること
ができる転送方式を提供することを目的としたも
のであつて、円筒磁区を保有しうる磁性薄膜上に
交流電流を流す穴開き導体層を有しその穴（以下
スロツトと称す）周辺の電流密度の乱れによつて
生じる時間変調された磁界勾配によつて円筒磁区
を駆動する記憶素子において、円筒磁区の初期駆
動を前記スロツトの中心部より行なうことを特徴
とする円筒磁区転送方式である。
次に本発明の詳細を図面を用いて説明する。第
１図は前記論文に示されている二層導体パタンの
一例である。
基板材料５上に円筒磁区を保持しうる円筒磁区
材料４が成長されており、その上に第一層目の円
筒磁区駆動用導体層３が設けられ、さらにその上
に絶縁層２を介して第二層目の円筒磁区駆動用導
体層１が設けられている。
８は円筒磁区であり矢印９，１０は各磁区中の
磁化の向きを表わす。
第一層目の導体層３には円筒磁区転送パタンと
してスロツト７が、また第二層目の導体層１には
スロツト６が設けられている。第２図は第１図の
スロツト列６，７を上から具たときの図である。
第一層目、第二層目の導体層にスロツト列と垂
直な向きの交流電流１１，１２を流すと半導層中
のスロツト６、及び７によりスロツト周辺に電流
分布のみだれが生じる。交流電流１１，１２の位
相を第３図に示すように1/4周期ずらすと、この
電流分布のみだれによつて生じるバイアス磁界分
布は進行波状になり円筒磁区は駆動力を受ける。
第３図では便宜上第一層目と第二層目の導体層に
流す電流密度の振幅を等しくしているが、第１図
に示されるように両導体層と円筒磁区材料までの
距離が異なるため両導体層による合成磁界が進行
波となるように両導体層の電流密度の大きさを設
定しなければならない。
第２図のように一定の周期で一列に並んだスロ
ツトを有する導体層における電流分布を与える式
はすでに前記論文中に記されているが具体的な計
算はされていない。第４図は前記論文中の式をも
とに、いくつかの形状のスロツトについて実際に
数値計算を行ないスロツト列の中心軸上のバイア
ス磁界分布を示したものである。図中Hzは発生磁
界のバイアス方向成分を円筒磁区膜厚について平
均した値である。a1，a2はスロツトの形状を表わ
すパラメータであり、a1はスロツト列と垂直方向
の長円軸の長さ、a2はスロツト列の同方向の長円
軸の長さである。数値計算において、スロツト列
の周期を8.0μｍ、円筒磁区膜厚を2.0μｍとして
いる。また電流は平面電流で近似し、電流平面と
円筒磁区膜の上面との距離を2500Åとしている。
第４図より明らかなように、スロツトの中心１
４の磁界勾配（△Ｈ）は隣接スロツトとの中間点
１６の磁界勾配よりも大きい。
この傾向は次表に示すようにａ２／ａ１の値が大きい
ス
ロツトほど顕著である。
The present invention relates to an initial drive method for cylindrical magnetic domains in a two-layer conductor pattern storage element. In a storage element that uses cylindrical magnetic domains as information carriers, the transfer method of the cylindrical magnetic domains involves applying an externally applied in-plane rotating magnetic field to a chiepron-shaped or Y-shaped pattern made of a soft magnetic film such as permalloy. Therefore, the so-called field access method, in which bubble magnetic domains are attracted to magnetic poles generated by sequential magnetization and transferred, has been common. However, in this field access method, as the cylindrical domain diameter is reduced to increase storage density,
The major drawback is that the in-plane rotating magnetic field required for cylindrical domain transfer increases rapidly, increasing power consumption and increasing the voltage applied to the in-plane rotating magnetic field generation coil, making it unsuitable for high-speed transfer. This is well known. Furthermore, as the diameter of the cylindrical magnetic domain becomes smaller, the minimum dimension necessary for forming a permalloy pattern becomes smaller, and it becomes extremely difficult to manufacture an element using a cylindrical magnetic domain of 2 μm or less. In order to overcome these shortcomings of the conventional field access type cylindrical magnetic domain element, a current access type two-layer conductor pattern storage element was developed by AH Bobeck in August 1979.
Bell System Technical Journal (He
Bell Syotem Feohnical Pournal) Volume 58, No. 6
No. 1, pp. 1453-1540. The essence of this two-layer conductor pattern memory element is that short or oval through holes are formed in a conductor layer provided on a cylindrical magnetic domain material, and when an alternating current is passed through this conductor layer, the current generated around the holes is The objective is to drive a cylindrical magnetic domain using a bias magnetic field distribution based on the distribution. A two-layer conductor pattern memory element needs to be driven with as little current as possible in order to reduce power consumption. As is well known, there is a particularly high probability that a transfer error will occur during the initial drive of a cylindrical magnetic domain. The present invention aims to provide a transfer method capable of reducing the probability of the above-mentioned initial transfer error and driving cylindrical magnetic domains with as small a current as possible. In a memory element that has a perforated conductor layer through which an alternating current flows and drives a cylindrical magnetic domain by a time-modulated magnetic field gradient generated by disturbances in current density around the hole (hereinafter referred to as a slot), the cylindrical magnetic domain This is a cylindrical magnetic domain transfer method characterized in that the initial drive is performed from the center of the slot. Next, details of the present invention will be explained using the drawings. FIG. 1 is an example of the two-layer conductor pattern shown in the paper. A cylindrical magnetic domain material 4 capable of holding a cylindrical magnetic domain is grown on a substrate material 5, and a first conductor layer 3 for driving the cylindrical magnetic domain is provided on the substrate material 5. A second conductor layer 1 for driving cylindrical magnetic domains is provided. 8 is a cylindrical magnetic domain, and arrows 9 and 10 represent the direction of magnetization in each magnetic domain. The first conductor layer 3 is provided with a slot 7 as a cylindrical magnetic domain transfer pattern, and the second conductor layer 1 is provided with a slot 6. FIG. 2 is a view of the slot rows 6 and 7 of FIG. 1 viewed from above. When alternating currents 11 and 12 are passed through the first and second conductive layers in a direction perpendicular to the slot rows, the current distribution is distorted around the slots due to the slots 6 and 7 in the semiconductor layer. When the phases of the alternating currents 11 and 12 are shifted by 1/4 period as shown in FIG. 3, the bias magnetic field distribution generated by the current distribution becomes a traveling wave, and the cylindrical magnetic domain receives a driving force.
In Figure 3, the amplitude of the current density applied to the first and second conductor layers is made equal for convenience, but as shown in Figure 1, the distances between both conductor layers and the cylindrical magnetic domain material are different. Therefore, the magnitude of the current density of both conductor layers must be set so that the combined magnetic field of both conductor layers becomes a traveling wave. Although the equation giving the current distribution in a conductor layer having slots arranged in a row at a constant period as shown in FIG. 2 has already been described in the above-mentioned paper, no specific calculations have been made. FIG. 4 shows the bias magnetic field distribution on the central axis of the slot array obtained by actually performing numerical calculations for slots of several shapes based on the equations in the above paper. In the figure, Hz is the average value of the bias direction component of the generated magnetic field with respect to the thickness of the cylindrical magnetic domain. a 1 and a 2 are parameters representing the shape of the slot, where a 1 is the length of the elliptical axis in the direction perpendicular to the slot row, and a 2 is the length of the ellipse axis in the same direction of the slot row. In the numerical calculations, the period of the slot row is 8.0 μm, and the thickness of the cylindrical magnetic domain is 2.0 μm. Further, the current is approximated by a plane current, and the distance between the current plane and the top surface of the cylindrical magnetic domain film is set to 2500 Å. As is clear from Fig. 4, the center 1 of the slot
The magnetic field gradient (ΔH) at 4 is larger than the magnetic field gradient at the intermediate point 16 with the adjacent slot. This tendency is more pronounced as the value of a 2 /a 1 becomes larger, as shown in the following table.
【表】
第５図ａ、第５図ｂはそれぞれ点１４，１６近
傍の磁界分布の違いをわかりやすく説明するため
に誇張して示してものである。第５図ｂでは第５
図ａとの磁界勾配の違いを比較しやすいよう磁界
勾配の符号を反転させてある。
表の△Ｈはこの図の磁界勾配△Ｈとして求めた
ものである。
以上に述べた通りスロツト列によるバイアス磁
界分布はスロツトの中心部とスロツト中間部とで
は異なつており、中心部の磁界勾配の方が大きい
ことが判明した。円筒磁区の駆動に於いては、バ
イアス磁界勾配が大きい方が駆動力が大きい。円
筒磁区駆動磁界勾配が大きいことは換言すれば、
円筒磁区駆動電流を小さくし得ることを示してい
る。すなわち、電流駆動型円筒磁区素子の消費電
力を小くすることが出来ることになる。更に、大
きな磁界勾配によつて円筒磁区の駆動速度は大き
くなり、このために駆動周波数を大きくすること
が出来、より高速の円筒磁区素子が可能となる。
このように本発明により円筒磁区の初期駆動を
スロツト中心部より行うと中間部で行うよりも大
きな円筒磁区駆動力が得られ、従つてより高速で
も安定に駆動出来、且つ、消費電力が少くてす
む。
スロツトの中心部より円筒磁区を駆動するに
は、円筒磁区をスロツト中心部に置くことが必要
である。円筒磁区駆動用導体層が二層以上の多層
構造をもつ円筒磁区素子では、第２図に示す如く
一つの導体層のスロツト中心部に重なる様に配置
した他層のスロツトの端部に円筒磁区を止めてお
けば良い。第４図に示す様にスロツトの端部１５
はバイアス磁場が一番大きく、且つ安定であるか
らである。
次に第６図を用いて本発明の実施例をさらに詳
しく説明する。本実施例は円筒磁区駆動層として
２層の導体層を有し第６図ａで示す構造をもつ場
合である。本発明の第１の実施例は、円筒磁区が
第２層の導体層１のスロツト６の中心部より駆動
されるとき、第６図ｂで示すように第１の導体層
３及び第２の導体層１に夫々駆動電流J1，J2を印
加する円筒磁区転送方式である。円筒磁区はスロ
ツト６の中心部にあるため、最大磁界勾配を受け
る。
本発明の第２の実施例は、第１の導体層のスロ
ツト７の中心部より円筒磁区を駆動するとき、第
６図ｃで示す位相から電流を印加する円筒磁区転
送方式である。この場合に於いても円筒磁区はこ
の初期駆動の際、最大磁区勾配を受ける。
本発明の説明において、スロツトの形状は長円
形のもについて述べてもたが、スロツト形状が長
方形もしくは楕円形などの形状であつても同様の
効果があることは容易に判る。
本発明によつて、従来時にエラーが起こりやす
かつた初期駆動時における転送特性を改善するこ
とができ換言すれば本発明の実施により最小駆動
電流が下げられチツプの消費電力を低減すること
ができる。[Table] Figures 5a and 5b are exaggerated diagrams to clearly explain the difference in magnetic field distribution near points 14 and 16, respectively. In Figure 5b, the fifth
The sign of the magnetic field gradient has been reversed to make it easier to compare the difference in magnetic field gradient from Figure a. ΔH in the table is determined as the magnetic field gradient ΔH in this figure. As mentioned above, it has been found that the bias magnetic field distribution due to the slot row is different between the center of the slot and the middle of the slot, and the magnetic field gradient at the center is larger. In driving the cylindrical magnetic domain, the larger the bias magnetic field gradient, the larger the driving force. In other words, the cylindrical domain driving magnetic field gradient is large.
This shows that the cylindrical domain drive current can be reduced. In other words, the power consumption of the current-driven cylindrical magnetic domain element can be reduced. Furthermore, the large magnetic field gradient increases the driving speed of the cylindrical domain, which allows the driving frequency to be increased, allowing for faster cylindrical domain elements. In this way, according to the present invention, when the cylindrical magnetic domain is initially driven from the center of the slot, a larger driving force for the cylindrical magnetic domain can be obtained than when it is driven from the middle part, and therefore it can be driven stably even at higher speeds, and consumes less power. Finish. In order to drive the cylindrical magnetic domain from the center of the slot, it is necessary to place the cylindrical magnetic domain at the center of the slot. In a cylindrical magnetic domain element with a multilayer structure in which the conductor layer for driving a cylindrical magnetic domain has two or more layers, the cylindrical magnetic domain is placed at the end of the slot of another layer arranged so as to overlap the center of the slot of one conductor layer, as shown in Fig. 2. It is better to stop. The end 15 of the slot as shown in FIG.
This is because the bias magnetic field is the largest and stable. Next, an embodiment of the present invention will be described in more detail with reference to FIG. In this embodiment, the cylindrical magnetic domain driving layer has two conductor layers and has the structure shown in FIG. 6a. In the first embodiment of the present invention, when the cylindrical magnetic domain is driven from the center of the slot 6 of the second conductor layer 1, the first conductor layer 3 and the second This is a cylindrical magnetic domain transfer method in which drive currents J 1 and J 2 are applied to the conductor layer 1, respectively. Since the cylindrical domain is in the center of the slot 6, it experiences the maximum magnetic field gradient. The second embodiment of the present invention is a cylindrical domain transfer method in which when driving the cylindrical magnetic domain from the center of the slot 7 of the first conductor layer, a current is applied from the phase shown in FIG. 6c. In this case as well, the cylindrical domain experiences the maximum domain gradient during this initial drive. In the description of the present invention, the slot has an oval shape, but it is easy to see that the same effect can be obtained even if the slot is rectangular or elliptical. According to the present invention, it is possible to improve the transfer characteristics at the time of initial drive, which were prone to errors in the conventional method.In other words, by implementing the present invention, the minimum drive current can be lowered and the power consumption of the chip can be reduced. .
第１図は公知のチツプ層構成を示す部分断面
図、第２図はスロツト６，７の配置をチツプ上面
からみて示した図、第３図は円筒磁区駆動用導体
層に流す電流波形を示す図、第４図はいくつかの
形状のスロツトについて、駆動電流によつて発生
する磁界分布を示した図、第５図ａ，ｂはそれぞ
れスロツトの中心部および中間部での磁界勾配を
示した図、第６図は本発明の実施例を示した図
で、ａは円筒磁区素子の概略図、ｂは第１の実施
例を示す電流波形図、ｃは第２の実施例を示す電
流波形図である。１，３……円筒磁区駆動用導体
層、２……絶縁層、４……円筒磁区材料、５……
基板材料、６，７……スロツト、１１……第１層
目の導体層に流す電流波形、１２……第２層目の
導体層に流す電流波形。
Fig. 1 is a partial sectional view showing a known chip layer structure, Fig. 2 is a view showing the arrangement of slots 6 and 7 as seen from the top of the chip, and Fig. 3 shows the waveform of the current flowing through the conductor layer for driving the cylindrical magnetic domain. Figure 4 shows the magnetic field distribution generated by the drive current for several shapes of slots, and Figures 5a and 5b show the magnetic field gradients at the center and middle of the slot, respectively. 6 are diagrams showing embodiments of the present invention, in which a is a schematic diagram of a cylindrical magnetic domain element, b is a current waveform diagram showing the first embodiment, and c is a current waveform diagram showing the second embodiment. It is a diagram. 1, 3... Conductor layer for driving cylindrical magnetic domain, 2... Insulating layer, 4... Cylindrical magnetic domain material, 5...
Substrate material, 6, 7...Slot, 11... Current waveform flowing through the first conductor layer, 12... Current waveform flowing through the second conductor layer.
Claims (1)
を流す穴開き導体層を有しその穴周辺の電流密度
のみだれによつて生じる時間変調された磁界勾配
によつて円筒磁区を駆動する記憶素子において、
円筒磁区の初期駆動を前記穴の中心部より行なう
ことを特徴とする円筒磁区転送方式。1 A memory element that has a perforated conductor layer through which an alternating current flows on a magnetic thin film capable of holding cylindrical magnetic domains, and drives cylindrical magnetic domains by a time-modulated magnetic field gradient generated by a current density drop around the holes. In,
A cylindrical magnetic domain transfer method characterized in that the initial drive of the cylindrical magnetic domain is performed from the center of the hole.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7234780A JPS56169284A (en) | 1980-05-30 | 1980-05-30 | Cylindrical magnetic domain transfer system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7234780A JPS56169284A (en) | 1980-05-30 | 1980-05-30 | Cylindrical magnetic domain transfer system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS56169284A JPS56169284A (en) | 1981-12-25 |
| JPS6243274B2 true JPS6243274B2 (en) | 1987-09-12 |
Family
ID=13486676
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7234780A Granted JPS56169284A (en) | 1980-05-30 | 1980-05-30 | Cylindrical magnetic domain transfer system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS56169284A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6293479U (en) * | 1985-12-03 | 1987-06-15 |
-
1980
- 1980-05-30 JP JP7234780A patent/JPS56169284A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6293479U (en) * | 1985-12-03 | 1987-06-15 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS56169284A (en) | 1981-12-25 |
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