JPH03130986A - Bloch line memory element and its manufacturing method - Google Patents

Abstract

PURPOSE:To extend a bias magnetic field margin for transferring the paired Bloch lines of a stripe magnetic domain end part by forming a magnetic substance pattern for leaked magnetic flux correction on a magnetic substance pattern to determine the bit positions of the paired Bloch lines. CONSTITUTION:A stripe magnetic domain 2 exists in a magnetic garnet thin film 100 and is fixed around a pattern 1 for stripe magnetic domain fixing. A pattern 7 for guiding read / write, pattern 8 for guard and pattern 1 are formed by providing a groove in the garnet film 100 itself. Paired Bloch lines 6 as an information carrier are made stable by a dummy Bloch line 5 and fixed by potential well made by magnetic substance patterns 3 and 3-1. Thus, a magnetic substance pattern 4 is formed on a polyimide resin spacer laminated on the patterns 3 and 3-1. Then, the patterns 3 and 4 are magnetized in the breadthwise direction of the pattern and in the almost same direction and in the upper and lower end parts of the pattern 3, a leaked magnetic flux is corrected.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a solid-state magnetic memory, and particularly to a Bloch line memory element suitable for realizing a large-capacity file memory.

[Conventional technology]

In a Bloch line memory element, the presence or absence of a Bloch line pair existing in the domain walls of striped magnetic domains arranged in parallel in a ferromagnetic material whose axis of easy magnetization is perpendicular to the film surface is determined by an information "1". 'O'', and it is important to determine the position of the Bloch line pair.As described in JP-A No. 59-98384, the method is as follows: In this method, a magnetic film pattern is periodically formed, and the position of the Bloch line pair is determined by utilizing magnetostatic interaction between the leakage magnetic field generated from the magnetic film pattern and the Bloch line pair.

[Problem to be solved by the invention]

In the above conventional technology, the leakage magnetic field distribution from the magnetic material pattern at the ends of the striped magnetic domains is significantly different from that at the center of the striped magnetic domains. Figure 5 (a) and (b)
is the distribution of the component (a) within the plane of the ferromagnetic film of the leakage magnetic field generated from the magnetic material pattern when periodically arranged strip-shaped magnetic material patterns are magnetized in the width direction, and the component perpendicular to the film. (b) shows the distribution. Regarding the in-plane component, the center part of the magnetic material pattern (the center part of the striped magnetic domain)
, the center value of the amplitude is constant, but the left and right ends (
At the ends of the striped magnetic domain), the -center value of the amplitude is smaller than that at the center. Regarding the vertical component,
At the center of the magnetic material pattern, the center value of the amplitude is approximately O, but at the left end it becomes negative and at the right end it becomes positive. Due to the difference in the in-plane component and the difference in the vertical component, the force acting on the Bloch line pair and the domain wall during transfer of the Bloch line pair differs between the center and the end of the striped magnetic domain. Therefore,
There is a problem in that the bias magnetic field margin for Bloch line pair transfer at the edge of the striped magnetic domain is extremely narrower than that at the center of the striped magnetic domain. An object of the present invention is to widen the bias magnetic field margin for transfer of Bloch line pairs at the ends of striped magnetic domains, and to widen the common margin with the bias magnetic field margin for transfer at the center of striped magnetic domains.

[Means to solve the problem]

The above purpose is to create a Bloch line memory in which information carriers are Bloch line pairs existing in the domain walls of striped magnetic domains arranged in parallel in a ferromagnetic film whose axis of easy magnetization is perpendicular to the film surface. In the device, this is achieved by providing a second magnetic pattern via a spacer on the first magnetic pattern that defines the bit position of the Bloch line pair formed directly on the ferromagnetic film or via a spacer. be done. The second magnetic material pattern may be formed so that the leakage magnetic field generated from the second magnetic material pattern corrects the leakage magnetic field at the end of the first magnetic material pattern. 1 Effect] A leakage magnetic field generated from a second magnetic pattern provided via a spacer on the first magnetic pattern that determines the position of the Bloch line causes a leakage magnetic field to be generated at the end of the first magnetic pattern. If the leakage magnetic field is corrected, the difference in leakage magnetic field distribution between the center and the edge of the stripe magnetic domain becomes smaller, and when the Prozcho line pair is transferred between the center and the edge of the stripe magnetic domain, the Bloch line pair and the domain wall are The difference in working force becomes smaller. As a result, the bias magnetic field margin for transfer of the Bloch line pair at the edge of the striped magnetic domain is widened, and the common margin with the bias magnetic field margin for transfer at the center of the striped magnetic domain is widened. 1 Embodiment An embodiment of the present invention will be described below with reference to Section Rvii and FIGS. 2(a) and 2(b). Figure 1(,) is a diagram showing the functional parts of the Bloch line memory element, and Figure 1v4(b) is the same diagram (,).
It is a sectional view when a) is cut along line segment AA'. Striped magnetic domain 2 is a 5 μm thick layer grown in liquid phase on a 0.4 μm thick gadolinium gallium garnet substrate.
exists in the CaGa-based magnetic garnet thin film 100 and is identified around the stripe magnetic domain fixing pattern l. The guide pattern 8 serves as a guide when stretching the striped magnetic domain during writing and reading of information.The guard pattern 8 prevents unnecessary magnetic domains from entering the functional section from the outside.1.7.8 Each pattern is formed, for example, by providing grooves in the magnetic garnet film 100 itself in which the striped magnetic domains 2 are present. The Bloch line 5 existing in the domain wall is a dummy Bloch line for keeping the Bloch line pair 6, which is an information carrier, stable. Bloch line pair 6, which is a carrier of information existing in the domain wall
is fixed by the potential well created by the magnetic pattern 3.3-1. The magnetic pattern 3.3-1 is
Grooves dug in the magnetic garnet film 100 are made of polyimide resin 1.
After flattening with 01. A 300 to 400 Co -P film was deposited thereon by sputtering, and a desired pattern was formed by photolithography. The residual magnetic flux density of the Go-Pt film is 50
It is 006. Also, the width of the magnetic pattern 3 is 1.25
μm, the alignment period is 2.5 μm, and the magnetic garnet film 10
The space with 0 is approximately 1 μm. The magnetic pattern 4 is a pattern for correcting the leakage magnetic field distribution at the upper and lower ends of the magnetic film pattern 3. The magnetic pattern 4 is
After laminating a polyimide resin 102 as a spacer on the magnetic pattern 3.3-1, a G o -P film was deposited thereon by sputtering, and a desired pattern shape was formed by photolithography. When the magnetic material film pattern 3 is formed under the above conditions, the magnetic material pattern 4 has, for example, (1) a film thickness of 300λ to 400% (2) a residual magnetic flux density of 5
000G (3) Width 5 to 10 μm (4) Distance to magnetic pattern 3-1 α1 to 2 μm (5) Space with magnetic garnet film 100 of about 2 μm,
When the magnetic material patterns 3 and 4 are magnetized in the width direction of the patterns and in substantially the same direction, the leakage magnetic field distribution at the upper and lower ends of the magnetic film pattern 3 can be corrected. Figure 2 (,
) and (b), when the magnetic material pattern 3.4 is formed under the above conditions, the combined leakage magnetic field generated from the two patterns is the component (a) in the plane of the magnetic garnet film 100, The component perpendicular to the magnetic garnet film 100 (b
). Looking at the in-plane component, there is almost no difference between the center value of the amplitude at the center of the pattern and the center value of the amplitude at the edges, and when looking at the vertical component, there is a difference between the center value of the amplitude at the center of the pattern and the center value of the amplitude at the edges. Therefore, when the Bloch line pair is transferred, there is no difference in the force acting on the Bloch line pair 6 and the domain wall between the center and the edge of the striped magnetic domain, and the Bloch line pair at the edge of the striped magnetic domain disappears. The bias magnetic field margin for transfer is widened. Then, the common margin with the bias magnetic field margin for transfer at the center of the stripe magnetic domain widens. FIG. 6 shows the bias magnetic field margin for transfer with and without the magnetic pattern 4. As is clear from this figure, when there is a magnetic material pattern 4,
The margin will be wider than without it. The leakage magnetic field generated from the magnetic material pattern 3 is corrected by the third
This can also be done using the magnetic material pattern 9 shown in Figures (a) and (b). The magnetic pattern 9 is formed by laminating polyimide resin 102 as a spacer on the magnetic pattern 3.
A Co-P film is deposited thereon by sputtering,
A desired pattern shape was formed by photolithography. When the magnetic material film pattern 3 is formed under the above conditions, the magnetic material pattern 9 has, for example, (1) a film thickness of 300 to 400 films, (2) a residual magnetic flux density of 2500 G, and (3) a thickness that covers the entire magnetic material pattern 3. Width (4) Space with magnetic garnet film 100 of approximately 1.5 μm (5) Coercive force of magnetic pattern 3 > Coercive force of magnetic pattern 9. Magnetic patterns 3 and 9 are aligned in the width direction of the pattern. and is magnetized in almost the opposite direction. The leakage magnetic field distribution at the upper and lower ends of the magnetic material pattern 3 can be captured. The magnetic patterns 3 and 9 are magnetized as follows. First, the magnetic pattern 3 is magnetized by applying a magnetic field greater than its coercive force from the outside in the width direction of the pattern. Next, a magnetic field larger than the coercive force of the magnetic material pattern 9 and smaller than the coercive force of the magnetic material pattern 3 is applied from the outside in the width direction of the pattern and in a direction opposite to the magnetization direction of the magnetic material pattern, so that the magnetic material is Magnetize pattern 9. FIGS. 4(a) and 4(b) show that when the magnetic patterns 3 and 9 are formed under the above conditions, the leakage magnetic field generated from the two patterns is synthesized and the magnetic garnet film 10 is
3 is a diagram showing a component (a) in the 0-plane and a component (b) perpendicular to the magnetic garnet film 100. FIG. Figure 2(a)
, (b), the leakage magnetic field from the magnetic material pattern at the ends of the stripe magnetic domains is corrected. According to this embodiment, the difference in the leakage magnetic field distribution from the magnetic material pattern between the central part and the end part of the striped magnetic domain becomes small.
The bias magnetic field margin for transfer of Bloch line pairs at the ends of striped magnetic domains can be widened, and the common margin with the bias magnetic field margin for transfer at the center of striped magnetic domains can be widened.

【Effect of the invention】

According to the present invention, the difference in the leakage magnetic field distribution from the magnetic material pattern between the center and the edge of the stripe magnetic domain becomes smaller, so it is possible to widen the bias magnetic field margin for Bloch line pair transfer at the edge of the stripe magnetic domain. It is possible to widen the common margin with the bias magnetic field margin for transfer at the center of the magnetic domain.

[Brief explanation of the drawing]

Figure 1 (a), (b) + Figure 3 - (a) and (b)
FIG. 2(a) is a configuration diagram of a storage section of a Bloch line memory element for explaining an embodiment of the present invention. (b), FIGS. 4(a) and (b) are diagrams for explaining the embodiments of the present invention, and FIGS. 5(a) and (b) are distribution diagrams of the leakage magnetic field generated from the magnetic material pattern. No. 6v4 is a bias magnetic field margin diagram for Bloch line pair transfer. Explanation of symbols l--Striped magnetic domain fixing pattern, 2--stripe magnetic domain, 3.3-1.4.9--magnetic material pattern, 5...Bloch line, 6... Bloch line pair , l--Guide pattern, 8-- Guard pattern, 100... Magnetic garnet, 101, 102...
Polyimide resin, α-・Distance between magnetic patterns 3-1.4. 11 3
lr #11
N 114
7 S''' 2nd, Gogosa / Figure 3 11.7 II
11 '7 IIノ/J-9 り 1 (A・Figure 4/71% 'r ゝ'°'1

Claims (1)

[Claims] 1. In a Bloch line memory element in which information carriers are Bloch line pairs in domain walls of striped magnetic domains arranged in a ferromagnetic film whose axis of easy magnetization is perpendicular to the film surface,
A leakage magnetic field from the first magnetic pattern is applied via the spacer onto the first magnetic pattern for determining the bit position of the Bloch line pair provided directly on the ferromagnetic film or via a spacer. A Bloch line memory element characterized in that a second magnetic material pattern is formed for correcting. 2. The Bloch line memory element according to claim 1, wherein the second magnetic material pattern has a leakage magnetic field generated from the magnetic material pattern at a center of the amplitude of the leakage magnetic field at an end of the first magnetic material pattern. A Bloch line memory element whose value substantially matches the center value of the amplitude of the leakage magnetic field at the center of the first magnetic material pattern. 3. The Bloch line memory element according to claim 1 or 2, wherein the second magnetic material pattern is provided outside both ends of the first magnetic material pattern, and the first magnetic material pattern and the second magnetic material pattern A Bloch line memory element in which magnetic material patterns are magnetized in at least the same direction. 4. The Bloch line memory element according to claim 1 or 2, wherein the second magnetic material pattern is provided so as to cover the entire first magnetic material pattern, and the second magnetic material pattern is provided with respect to the first magnetic material pattern. A Bloch line memory element in which two magnetic material patterns are magnetized in almost opposite directions. 5. The Bloch line memory element according to claim 4, wherein the coercive force of the second magnetic material pattern is smaller than the coercive force of the first magnetic material pattern. 6. The method for manufacturing a Bloch line memory element according to claim 5, wherein after magnetizing the first magnetic material pattern in one direction by applying an external magnetic field larger than its coercive force, the first magnetic material pattern and applying an external magnetic field smaller than the coercive force of the second magnetic material pattern and larger than the coercive force of the second magnetic material pattern in a direction substantially opposite to the direction in which the first magnetic material pattern is magnetized. A method for manufacturing a Bloch-Rhein Memory element, comprising the step of magnetizing the magnetic material in a direction substantially opposite to that of the first magnetic material pattern. 7. The Bloch line memory element according to claim 1, wherein the magnetic material pattern is a high coercive force film pattern whose easy magnetization direction is the longitudinal direction of the striped magnetic domain. 8. The Bloch line memory element according to claim 1, wherein the magnetic material pattern is a high coercive force film pattern whose easy magnetization direction is substantially perpendicular to the film surface of the ferromagnetic film.