JPS60136082A - Magnetic bubble element - Google Patents

Abstract

PURPOSE:To obtain a high density ion implanted transfer path having a wide range of action marging and no dependance on the bubble transfer mode, by setting the width of a transfer path pattern within a specific range. CONSTITUTION:The width (a) of a transfer path pattern is set at 1.4<=a/d<=2.4 with lambda/d>=3, where lambda means a meandering cycle and (d) and (a) defined as the bubble diameter and the pattern width, respectively. For instance, a meandering ion implanting pattern for 1mumphi bubble is obtained with a=1.5mum, lambda=3mum and W=2.5mum, respectively together with an ion implanting pattern for 1mumphi bubble obtained with a=1.5mum, lambda=3.5mum and W=2mum, respectively. Thus it is possible to transfer the 1mumphi bubble with excellent characteristics having >=11% action margin width.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a magnetic bubble transfer path of a magnetic bubble device, and particularly to a magnetic bubble device having an ion implantation transfer path with a wide bias magnetic field margin suitable for reducing cell size. Regarding.

[Background of the invention]

Among the ion implantation transfer paths, a meandering transfer path is used by Be1l, 5yst, Tech, J,
vol, 5g.

1), 229 (1980). In this case, the purpose is to move the bubble through the non-implanted portion, and it is better to make the width of the pattern as small as possible. When a minor loop is formed using this transfer path, the shape shown in FIG. 1 is obtained. In the figure, region 2 is a region where an in-plane magnetization layer is formed on the surface of the IT bubble material by ion implantation, and region 1 is a region where there is no in-plane magnetization layer or where the in-plane magnetization layer is thinner than region 2. .

3 indicates a magnetic bubble. This transfer path has a period of 4 μm for a 1 μmφ bubble, but if this shape is preserved and a minor loop with a period of 4 μm or less is constructed using the same 1 μmφ bubble, the following problem arises. That is, when m transfer paths with a cell size of 4 μm x 4 μm or less are formed, the problem is that the operating margin varies greatly depending on the difference in the bubble transfer mode. In particular, when the bubbles intersect within one loop as shown in Figure 2, the operating margin of a single bubble deteriorates significantly from 4 to 5 in the rotating magnetic field 500e as shown in Figure 3. That's what I found out.

The above characteristics have been a major obstacle in realizing a higher density magnetic bubble element using materials with the same bubble diameter.

[Purpose of the invention]

An object of the present invention is to provide a high-density ion implantation transfer path that has a wide operating margin and has characteristics that are independent of the bubble transfer mode.

[Summary of the invention]

The present invention was devised based on the fact that the bias magnetic field margin depends on the width of the transfer path pattern.

Figure 4 shows cell sizes 3 and 5 using 1 μmφ bubbles.
These are the results of measuring the dependence of the operating margin on the pattern width a in a meandering ion implantation transfer path of 3.5 μm2. The bubble transfer mode evaluated here is state 5 shown in the %3 diagram. The maximum width W of the pattern is 3 μm.

From the coil D graph, a/d is 1.4 x a/d x 2.
It is clear that a range of 4 shows good characteristics with an operating margin of 10% or more.

It was found that for a rod 1 case using a 1 μmφ bubble, the above-mentioned theory holds true when the period λ of the transfer path is 3 μm or more.

In other words, when -2r≧3, it is sufficient to set a within the range of 1.4 to 2.4.

(λ: period of meandering, d: bubble diameter, a: pattern width) [Embodiments of the Invention] Hereinafter, embodiments of the present invention will be explained with reference to FIGS. 5 and 6.

In Figure 5, a = 1.5 μm, λ = 3 μm, W = 2.5 μm.
This is a serpentine ion implantation pattern for a 1 μmφ bubble where m is a diameter of 1 μm.

Figure 6 shows a=1.5μm, λ=3.5μm, W=2μm.
This is an ion implantation pattern for a 1 μmφ bubble where m is the diameter of the ion implantation pattern.

In these four examples, it was possible to transfer a 1 μmφ bubble with good characteristics with an operating margin width of 11% or more. In addition, if the above 1≧3, 1.4<7×2
The range of 4 was the same for other bubble diameters d.

The bubble diameter d described above is equivalent to the strip magnetic domain width.

〔Effect of the invention〕

According to the present invention, when materials having the same bubble diameter are used, it is possible to advantageously form ion implantation transfer paths with high density. That is, until now, the gill size was generally 16d2 for the bubble diameter d, but with the present invention, it is possible to operate by changing the cell size down to about 10d''.In this way, the magnetic bubble element This has a great effect on increasing the density of

[Brief explanation of drawings]

Figure 1 is a plan view of the meandering ion implantation transfer path, Figure 2 is a diagram showing the state in which bubble rows intersect in the meandering ion implantation transfer path, and Figure 3 is the operating bias due to differences in bubble transfer modes. FIG. 4 is a graph comparing the magnetic field range, and FIG. 4 is a graph showing the relationship between the ratio a/d of bubble diameter d and pattern width a and the operating margin. FIGS. 5 and 6 each show an example of the present invention. FIG. 1... Non-ion implantation region, 2... Ion implantation region, 3... Magnetic bubble, 4... Characteristics of isolated bubble,
5...Continued from page 1 0 Inventor Sugi 1) Ko Kokubunji City Higashi Koigakubo Laboratory

Claims (1)

[Claims] A magnetic medium that has uniaxial anisotropy and generates a bubble domain by applying a perpendicular magnetic field to its surface, and a region formed by ion implantation in a part of the magnetic medium, and its magnetic The bubble transfer path is a meandering pattern, and the meandering period λ is the bubble diameter d. A magnetic bubble element characterized in that in a portion where i≧3, the width a of the meandering pattern is in the range of 1.4<2.4.