JPS62214579A - Hybrid type magnetic bubble memory element - Google Patents

Abstract

PURPOSE:To decrease the interaction between bubbles and to prevent the deterioration of a margin by implanting ions for hard bubble control only to the 'Permalloy(R)' transfer path region without implanting the ions for hard bubble control to an ion implantation transfer path region. CONSTITUTION:A bubble crystal 11 is formed in a substrate 10 of a hybrid type magnetic bubble memory element and double ion implantation layers 12 for forming the ion implantation transfer path are formed in the crystal 11. The ions for the hard bubble control are implanted only in the 'Permalloy(R)' transfer path region 16 without implanting the ions for hard bubble control into the ion implantation transfer path region 14 of the memory element. A boundary l between the region implanted with the ions for hard bubble control and the region not implanted with the ions is disposed in the region commonly occupied by the ion implantation transfer path 13 and the 'Permalloy(R)' transfer path 15 of the junction pattern. The interaction between the bubbles is decreased and the deterioration of the margin is prevented.

Description

[Detailed Description of the Invention] [Summary] This is a hybrid magnetic bubble memory element, in which ion implantation for hard bubble suppression is performed only in the permalloy transfer path region and not in the ion implantation transfer path region. It reduces the interaction between bubbles in the injection transfer path, making it possible to improve the transfer margin.

[Industrial application field]

The present invention relates to a hybrid magnetic bubble memory element used in a storage device such as an electronic computing device.

Magnetic bubble memory elements have conventionally used soft magnetic thin film patterns such as permalloy as the bubble transfer path, but recently, as storage devices have become more sophisticated, patterns have become finer, and their shapes have become shiny, making it difficult to use lithography. It's becoming. For this reason, a bubble transfer path using an ion implantation method that does not require a gap between patterns is attracting attention. However, if the entire device is constructed of ion-implanted transfer paths, gate characteristics will be poor and margins will deteriorate. For this reason, the minor loop for information storage, which occupies the main area of the memory, uses an ion-implanted transfer path suitable for high density, and the major line, which includes read/write gates, uses a hybrid type that uses a permalloy transfer path with a proven track record. magnetic bubble memory is becoming mainstream.

[Conventional technology]

Ion implantation in conventional hybrid magnetic bubble memory elements involves double ion implantation to form ion implantation transfer paths, and ion implantation for hard bubble suppression uses common ion implantation conditions for both the ion implantation region and the permalloy transfer path region. Full-surface ion implantation was performed.

[Problem that the invention seeks to solve]

In the above conventional hybrid magnetic bubble memory element,
There are the following problems. FIG. 6 is a cross-sectional view of the ion implantation transfer path. Since the easy magnetization direction of the ion implantation layer 3 for suppressing hard bubbles formed in the bubble crystal 2 is in the in-plane direction, the magnetic flux flows easily and the ions The two bubbles 5.5' in the transfer path formed by the injection layer 4 are susceptible to the magnetic stray field emitted by each other, resulting in an error as shown in FIG. In the figure a, when there are bubbles A and B on the transfer path 6-H, bubble A near the tip disappears. In Figure b, when there are bubbles A and B traveling in the same direction on the transfer path 6, bubble B is delayed. 0
In the figure, bubble A on transfer path 6 jumps to adjacent transfer path σ. All of these are caused by the influence of bubble B, and greatly deteriorate the margin.

The present invention was created in view of these points, and an object of the present invention is to provide a hybrid magnetic bubble memory element that has a simple configuration and can improve the transfer margin.

[Means for solving problems]

Therefore, in the present invention, in a hybrid magnetic bubble memory element which is a hybrid of an ion-implanted bubble memory element and a permalloy bubble memory element, ion implantation for hard bubble suppression is not performed in the ion-implanted transfer path area 14. , is characterized in that ion implantation for suppressing hard bubbles is performed only in the permalloy transfer path region 16.

[For production]

By not performing ion implantation for suppressing hard bubbles in the ion implantation transfer path region, interaction between bubbles in the ion implantation transfer path is reduced, making it possible to prevent margin deterioration.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the present invention, in which a is a plan view;
b is a cross-sectional view taken along the line b-b'-b'' in figure a. In the same figure, lO is the substrate, 11 is a bubble crystal, and 12
is a double ion implantation layer for forming an ion implantation transfer path, 1
3 is an ion implantation transfer path, 14 is an ion implantation transfer path region,
15 is a permalloy transfer path, 16 is a permalloy transfer path region, 17 is an ion implantation layer for suppressing hard bubbles, 1. is ion implantation for hard bubble suppression, It, It is ion implantation for forming an ion implantation layer transfer path, and l is the boundary of the ion implantation region for hard bubble suppression.

In this embodiment, as shown in FIG. 1, ion implantation for hard bubble suppression is not performed in the ion implantation transfer path region 14,
This is carried out only in the permalloy transfer path head area 16, and its boundary l is placed in the common part of the ion implantation transfer path 13 and the permalloy transfer path 15 of the permalloy-ion implantation transfer path junction pattern.

This embodiment configured as described above does not perform ion implantation for hard bubble suppression into the ion implantation transfer path head region 14, so that: 1) interaction between bubbles in the ion implantation transfer path 13 is reduced; 2) compared to the conventional method; Since the thickness t of the bubble layer can be increased by the thickness d3 of the hard bubble suppressing ion implantation layer 17, the bias level of the margin can be increased.
The notching with the permalloy transfer path 15 is improved.

The thickness d of the hard bubble suppressing ion implantation layer 17 is approximately 500 μm in the case of a device using 0.93 μm bubbles.
It's a person. d, +d (where d is the thickness of the ion implantation layer for forming the ion implantation transfer path) are approximately 0.3 μm. However, these values are when implantation is performed under the conditions shown in Table 1 as the ion implantation conditions.

As shown in Table 1, the thickness t of the bubble layer can be increased by 68 times the thickness of the ion-implanted layer 17 for suppressing hard bubbles, so the collapse magnetic field can be increased.

As a concrete value, the number increases by about 80e for 500 people.

FIG. 2 shows a comparison between the margin of the permalloy section and the margin of the ion implantation transfer section. In the figure, curve A is a permalloy transfer path (half disk with a period of 14 μm), curve B is an ion implantation transfer path without ion implantation for hard bubble suppression, and curve C is an ion implantation transfer path without ion implantation for hard bubble suppression. In some cases. From the figure, it can be seen that in the ion implantation transfer path, bias matching is better without ion implantation for suppressing hard bubbles. Note that the ion implantation conditions are as shown in Table 1.

■Ion implantation transfer path region 14 and permalloy transfer path region 1
Since the difference in film thickness at the ion implantation boundary that separates the ion implantation transfer path 13 and the permalloy transfer path 1 can be reduced,
The transfer margin at the junction with 5 can be improved.

In a hybrid device, the ion implantation boundary must be passed through, but at this boundary there is a potential barrier that prevents bubble transfer, as shown in FIG.

In order for the bubble to move from the permalloy transfer path side to the ion implantation transfer path side, it must cross a barrier of height Ba, and vice versa, it must cross a barrier of height Bb.

The height of this barrier increases as the depth of the ion implantation layer or the strain of the ion implantation layer increases. (Reference J,
A, P, 53(3) 2513 (1982)) The height of the ion implantation boundary is d when there is an ion implantation layer 17 for suppressing hard bubbles, as shown in Figure 4a. However, when the present invention is applied, it is sufficient to obtain an ion implantation layer of depth d in the ion implantation transfer path region.
The height at the boundary becomes dd as shown in Figure 4, which is reduced by d3, and as a result, for the above reasons, the barrier created at the boundary is lowered and the margin of the joint is improved. .

Next, in the case of the present invention, a boundary β occurs between the hard bubble suppressing ion implantation region of the permalloy region and the double implantation region of the ion implantation transfer path region at (-) shown in FIG. This is because the distortion caused by ■1 in the figure and the distortion caused by IZ+13 are slightly different, and the third
It is thought that a barrier as shown in the figure is generated. Although this barrier is not considered to be much of a problem because the difference in strain is small and the depth of The boundary l that crosses the bubble transfer path must be brought to point F of the permalloy pattern, which has a strong driving force. Moreover, since the effect of suppressing hard bubbles must be maintained,
The requirement is that the ion implantation region be under the permalloy pattern.

Next, a manufacturing method for carrying out the present invention will be explained with reference to FIG. In the figure, a is a cross-sectional view of the first step, b is a plan view thereof, C is a cross-sectional view of the second step, d is a plan view thereof, e is a cross-sectional view of the third step, and f is a plan view thereof. .

To explain with the drawings, first, as shown in Figs.
(See Table 1). After that, the mask 20 is removed,
As shown in FIGS. c and d, a resist film 21 is formed using a mask pattern that covers only the ion implantation transfer path head region 14. (For this, a mask material such as the above-mentioned Au may be used.

(Since the energy is low, a simple resist material may be used.) Next, using this resist material 21 as a mask, ions are implanted only into the permalloy transfer path region 16 under the conditions of, for example, (1) in Table 1. Finally, as shown in figures e and f, the resist 21 is removed to complete the process.

〔Effect of the invention〕

As described above, according to the present invention, interaction between bubbles can be reduced and margin deterioration can be prevented with an extremely simple configuration, which is extremely useful in practice.

[Brief explanation of drawings]

Figure 1 is a diagram showing an embodiment of the present invention, Figure 2 is a diagram comparing the margin of the permalloy part and the margin of the ion implantation transfer part, and Figure 3 is a diagram showing the barrier (potential barrier) at the ion implantation boundary. 4 is a diagram showing the layer structure of the ion implantation layer near the ion implantation boundary. FIG. 5 is a diagram for explaining the manufacturing method for carrying out the present invention. 7 is a diagram showing the transfer error mode due to the interaction between bubbles. In FIGS. 1, 3, 4, and 5, 10 is the substrate, and 11 is the bubble crystal. , 12 is a double ion implantation layer, 13 is an ion implantation transfer path, 14 is an ion implantation transfer path region, 15 is a Permalloy transfer path, 16 is a Permalloy transfer path region, 17 is an ion implantation layer for hard bubble suppression, and 20 is a mask. , 21 is a resist film.

Claims (1)

[Claims] 1. In a hybrid magnetic bubble memory element which is a hybrid of an ion-implanted bubble memory element and a permalloy bubble memory element, the ion-implanted transfer path region (14) is implanted with ions for suppressing hard bubbles. Permalloy transfer path area (16
) A hybrid magnetic bubble memory element characterized in that only ion implantation is performed to suppress hard bubbles. 2. In the hybrid magnetic bubble memory device according to claim 1, the boundary (l) between the hard bubble suppressing ion implantation region and the non-ion implantation region is formed in the junction pattern of the permalloy-ion implantation transfer path. A hybrid magnetic bubble memory element characterized in that it is arranged in a shared portion of an ion implantation transfer path (13) and a permalloy transfer path (15).