JPS6145487A - Ion implantation type magnetic bubble memory element - Google Patents

Abstract

PURPOSE:To obtain an ion implantation type magnetic bubble memory element having a magnetic bubble tansfer line prevented from the generation of abnormal transfer at a position close to a magnetic bubble detector by forming a non- ion implantation area close to the detector as a prescribed shape. CONSTITUTION:The ion implantation area is formed as a prescribed shape and a non-ion implantation layer 2' on the back of a transfer line 6 is removed at a cusp B arranged before a cusp A detecting a magnetic bubble of an ion implantation transfer line 6 by one bit at a position close to the detector. Since the charged wall from the cusp B to the cusp A is easily formed on the basis of the shape of the layer 2', the magnetic bubble reaches the cusp A precisely. Consequently, the ion implantation type magnetic bubble memory element having the magnetic bubble transfer line prevented from the generation of abnormal transfer near the magnetic bubble detector is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnetic bubble memory device, and more particularly to an improvement of a transfer path near a detector in a magnetic bubble memory device having an ion implantation transfer path.

[Background of the invention]

In a magnetic bubble memory element having an ion-implanted transfer path, the detector that was conventionally considered to have good characteristics was one formed on the non-ion-implanted regions 2, 2' as shown in FIG. (The number 3 indicates the implantation area.) The configuration shown in FIG. 1 is based on T-J, Nelson et al.
``Design of bubble device element for use in ion implantation transfer path
device elements employing
ion implan seed propagat, io
Bell System Technical Journal
Cal Journal) ff, Vol. 59, p. 129 (1980).

The magnetic bubble 1 for reading is attached to the major line 6 (
Major Line) to the detector. When magnetic bubble 1 reaches recess A (cusp A) of the transfer path, A
Magnetic bubble expander (S Hiretc) consisting of U-conductor
her) 5 causes the magnetic bubbles l to extend in a band-like manner along the grooves of the stretcher 5. When a strip-shaped magnetic domain comes under a detection line 4 made of a magnetoresistive element, the magnetic resistance of the detection line 4 changes, and a magnetic bubble (here, a strip-shaped magnetic domain) is detected. Here, the detection region 2' where the magnetic bubbles extend in a band-like shape is formed by shallow ion implantation (50°C) to suppress so-called hard bubbles.
~10100n only. Figure 2 shows the first
It is a diagram schematically showing the cross-sectional structure of the detector shown in the figure. In the figure, a spacer such as a 5in2 film, 8 and 8' are magnetization directions, 9 is a hard bubble suppressing layer, 10 is a garnet film, and 1' is a strip-shaped magnetic domain. The reason why deep ion implantation (approximately 3/1 to 1/3 of the film thickness of the magnetic bubble) is not performed to form a magnetic bubble transfer path in the detection region 2' is as follows: (1) The magnetic bubble (strip magnetic domain) 1' (ii) Keep the height of the magnetic bubble 1' as large as possible, and
' detection signal (leakage magnetic field from magnetic bubble 1' (str
This is to strengthen the ay field).

However, as a result of a detailed study of the transfer characteristics of the magnetic bubble 1 in this transfer path, it was found that the following transfer abnormality is likely to occur near the detector.

In other words, in Figures 3(a) and (b), (a)
After M air bubble 1 is transferred to cusp B in front of cusp A in the center of the detector, it passes through cusp A and reaches cusp C.
The magnetic bubble 1 cannot be detected because the magnetic bubble 1 flies away (skip mode) (FIG. 4(a)).

(b) The magnetic bubble 1 is captured by the cusp B or a cusp before it (trap mode), and subsequent transfer of the magnetic bubble 1 becomes impossible ((b) in the same figure).

Such inconveniences arose, and some kind of improvement was desired.

[Purpose of the invention]

Therefore, an object of the present invention is to provide an ion implantation type magnetic bubble memory element having a magnetic bubble transfer path that does not cause transfer abnormalities in the vicinity of the magnetic bubble detector as described above.

[Summer of invention]

The gist of the invention is to provide a first non-ion implanted region consisting of a transfer path with a recess for transferring magnetic bubbles, and a first non-ion implanted region perpendicular to and on the transfer path for forming a magnetic bubble detector. a second non-ion implantation region provided in the opposite direction, and the second non-ion implantation region where the first non-ion implantation region and the second non-ion implantation region join together. An ion implantation type magnetic bubble memory characterized in that an end face of the portion is located at least at an intermediate position between a recess on the transfer path corresponding to the magnetic bubble detector and a recess 1 bit before the recess. It's in Motoko.

In order to achieve the above objective, it is necessary to investigate the cause of the above transfer abnormality. For this reason, in an ion-implanted magnetic bubble memory element, a special domain wall (a domain wall with nine magnetic poles formed in an in-plane magnetization layer, so-called a charged wall) is used as a driving force for magnetic bubbles.
We investigated the behavior of ll)) in detail. In Figure 4, magnetic fluid is dropped onto the sample surface and kn? X charged
It schematically shows the state of the wall. In the vicinity of the detector, the phase θ2 of the charged wall 11 (the phase θ2 of the charged wall 11 relative to the direction of the rotating magnetic field HR
d wall 11 position) is the phase θ of the other transfer path,
It turns out that it always lags behind. The cause of this is the M-work indicated by the arrow in the figure.

The reason is that the direction and magnitude of in-plane magnetization indicated by M2 are different between the vicinity of the detector and other parts. More specifically, since it is difficult for the magnetization M2 to take the same direction near the detector, the appearance of the charged wall 11 is delayed compared to other areas. That is, by positioning the non-ion implantation region 2' for the detector on the back side of the magnetic bubble transfer path 6, the charged
Is the phase 0□ of wall 11 different from the other phases 0□ and the above transfer difference? This will cause a problem.

Therefore, in order to improve the transfer abnormality, it is best to eliminate the non-ion implanted layer in the detector section. but,
As mentioned in the prior art section, a non-ion implanted layer is necessary to improve the detection output. Therefore, the present invention recognizes the existence of the non-ion implanted layer and provides a magnetic bubble transfer path that does not impede detection of magnetic bubbles and does not cause transfer abnormalities.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in detail with reference to Examples.

5(a) to 5(f) are examples of the ion implantation transfer path near the detector in the ion implantation type magnetic bubble memory device invented to improve the above-mentioned transfer abnormality. Figure (a) shows that in the process of a magnetic bubble moving from cusp A, where a magnetic bubble is to be detected, from cusp B, which is in front of Leavitt, to cusp A, from cusp B to cusp A, excluding the non-ion implantation M2' on the back side of transfer path 6. c in
This facilitates the formation of a harged wall and allows the magnetic bubble to successfully reach the detection location, that is, the cusp A. Figure (b) shows an example in which the width of the non-ion implanted layer 2' is gradually narrowed as it approaches the transfer path 6, and Figure (C) shows an example in which the width of the non-ion implanted layer 2' is uniformly narrowed. In the example, the figure (d) shows that the non-ion implantation J''!:12' of the detector is connected to the non-ion implantation layer 2 of the transfer path 6.
Figure (e) shows an example in which a magnetic bubble transfer path 6' is also formed on the back side of the transfer path 6, and
Figure (f) shows the magnetic bubble transfer path 6 near the detector.
The length of the synchronization is made longer than that of the other parts, and the width of the detector part is made relatively narrower. In addition, Fig. 5 (a
), (b), (c).

In (e) and (f), the width of the joint between the non-ion implanted region 2 and the non-ion implanted region 2' must be narrower than the intermediate position between cusp A and cusp B, which is less than the intermediate position. This is because it has been confirmed that it is not possible to completely suppress transfer abnormalities by narrowing the range.

If the position is above the intermediate position, the effect of suppressing transfer abnormalities can be obtained, and it may be completely eliminated as shown in FIG. 2(d). However, in this case, if the distance between region 2 and region 2' becomes too large, it is not preferable because it will hinder the expansion of the magnetic bubble. Results using the transfer patterns shown in FIGS. 5(a) to 5(f) above.

We were able to significantly suppress the abnormal transfer of magnetic bubbles in the vicinity of conventional detectors.

〔Effect of the invention〕

As described above, according to the present invention, it has become possible to provide an ion implantation type magnetic bubble memory element that completely eliminates abnormal transfer of magnetic bubbles on a magnetic bubble transfer path in the vicinity of a detector.

[Brief explanation of drawings]

Figure 1 is a block diagram of the vicinity of the detector in a conventional ion implantation type magnetic bubble memory element, Figure 2 is a sectional view of the magnetic bubble memory element in Figure 1, and Figures 3 (a) and (b).
) are schematic diagrams for explaining transfer abnormalities in the vicinity of the detector, FIG. 4 is a schematic diagram for explaining the present invention in detail, and FIGS. 5(a) to (f) are schematic diagrams for explaining the ion implantation according to the present invention, respectively. FIG. 2 is a configuration diagram of an embodiment near a detector in a type magnetic bubble memory element. DESCRIPTION OF SYMBOLS 1... Magnetic bubble, 2, 2'... Non-ion implantation area, 3... Ion implantation area, 4... Detection line, 5...
...Stretcher, 6...Transfer path, 7...Spacer, 8.8', 1'2...Magnetization direction, 9...Hard bubble suppression layer, 10...Garnet film, 11...・Charged wall, A, B, C...cusp, 0□, θ
2...Phase angle, 11□...Rotating magnetic field. WJ 3 Figure 4 (2) 2' (α) (e) ■ (b>C child)

Claims (1)

[Claims] 1. A first non-ion implantation region consisting of a transfer path having a recess for transferring magnetic bubbles, and a first non-ion implantation region perpendicular to and in the opposite direction from the transfer path to form a magnetic bubble detector; a second non-ion implantation region provided in the second non-ion implantation region, the end face of the second non-ion implantation region where the first non-ion implantation region and the second non-ion implantation region are joined to at least the second non-ion implantation region; An ion implantation type magnetic bubble memory element, characterized in that it is configured to be located at an intermediate position between a recess on the transfer path corresponding to a magnetic bubble detector and a recess 1 bit before the recess.