JPH03137885A - Magnetic bubble element - Google Patents

Abstract

PURPOSE:To decrease a driving current value by stretching a magnetic bubble along the border of an ion implantation transfer path. CONSTITUTION:The border of the ion implantation transfer path is low in potential energy, so the bubble can be stretched along the border with low energy and a necessary working pulse current may be small. The bubble (b) which is transferred to a position A is stretched along the border of the transfer path 30 by supplying a pulse current to a conductor 40. The bubble (b) is stretched in a cord shape from the point A to a point C along a groove in the hairpin of a conductor 40. The current value required for the stretching may be small because of the low energy and a cord-shaped bubble b1 which is stretched from the point A to the point C is obtained. Then the bubble is stretched to a point B into a bridge shape between two transfer paths 20 and 30 and the cord-shaped bubble b1 is grown to b1-2. Consequently, a driving current value required for the bridge operation of the bubble may be reduced.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a magnetic bubble element using an ion implantation transfer path, and in particular, to a magnetic bubble device including a gate circuit for exchanging bubbles between two types of transfer paths. The present invention relates to a magnetic bubble element.

[Conventional technology] A highly integrated device is realized by using an ion implantation pattern instead of the conventional permalloy thin film pattern as a bubble transfer path, which is a basic component of a magnetic bubble memory device. is known to be possible.

The transfer path of the ion implantation method generally has a structure as illustrated in FIG. In the figure, 1 is a magnetic film that is a medium for magnetic bubbles, and magnetic bubbles Bu exist in this film. On the surface of this magnetic film 1, for example, H2'', H
By implanting ions such as ``e'' and Ne'', a bubble transfer path 1o is formed.

The outer region 2 of 10 is the region into which ions are implanted.

The magnetic bubble Bu is transferred as follows.

By magnetizing the ion implantation layer I2 around the transfer path 10 by applying a magnetic field HR rotating in the plane from the outside as a magnetic field for driving the bubble.

Bubbles can be transferred along the boundaries of the transfer path 10. Regarding such ion implantation transfer paths, for example, IE Transactions Magnetics, Vol. 13, No. 6, pp. 1744-1.
764 pages, November 1977 (I E”Trans,
Magn, MAG-13, No. 6 (1977) P
, 1744-1764).

A magnetic bubble device requires a gate circuit as a basic component. This gate circuit is usually

It is a circuit that has the function of receiving and passing bubbles between an input/output transfer path called a major line and a closed-loop transfer path called a minor loop that circulates bubbles, and between these two transfer paths, This is achieved by providing a conductor pattern with a part bent into a hairpin shape and passing a pulsed current through it. An example of a conventional pattern of this gate circuit is shown in FIG. In the figure, 20 is an input/output transfer path, and 30 is a part of a closed loop transfer path. 4o indicated by a broken line is a part of a conductor pattern through which a pulse current flows.

The gate operation of the gate circuit having such a configuration is basically performed by combining the following two types of functions, and can be considered by being separated into these two types of functions.

(a) Bubble b transferred through the transfer path is transferred to the two transfer paths 20
For example, from point A to point B in the figure.

(b) Bridged string-shaped bubble b1 to b2゜b3
Cut and divide into two parts. Alternatively, the bridged string-like bubble b1 is moved from one transfer path to the other transfer path.

The operations (a) and (b) above are performed by passing a pulse current through the conductor pattern 40.

In the example shown in the same figure, in order to simplify the drawing, only the conductor pattern 40 that bridges the above-mentioned bubbles (,) related to the present invention is shown, and the conductor pattern 40 that is cut into two (
The conductor pattern that performs the operation b) is omitted.

Regarding such gate circuits, for example,
JP-A No. 62-259291 can be mentioned.

[Problems to be Solved by the Invention] The conventional ion implantation type gate circuit as described above has the following first-order problems. That is, in FIG. 2, bubble b is placed at point A1. Bridge between points B, bl
A pulse current Ist was passed through the conductor 40 in order to realize the stretching function as shown in FIG. The problem is that unless this operating pulse current Ist of 200 to 300 mA is applied, the bubble b will not bridge. Although not omitted in Fig. 2, in an actual bubble device, there are 500 to 600 gate circuits as shown in Fig. 2, and these conductor patterns 4o are connected in series. Take.

When attempting to flow a current of 200 to 300 mA through such a conductor 40, a driving voltage of 50 to 100 V is required, and since the device is designed to achieve high density, dielectric strength becomes a problem. In order to lower the drive voltage, instead of connecting the conductors 40 in series, a plurality of blocks (4
This can be handled by dividing the system into ~8 pieces) and connecting them in parallel. However, in this case, since the total current value is proportional to the number of divided blocks, the total current value is about 1 to 2.5 A, making the drive circuit impractical. Furthermore, since the current value of Ist is large, problems such as deterioration of element characteristics due to temperature rise due to heat generation due to Joule heat, and life span due to migration occur.

Therefore, an object of the present invention is to solve such conventional problems, and to provide a magnetic bubble element equipped with a gate circuit that can realize stable bridge operation even with a smaller pulse current Ist. .

[Means for Solving the Problems] In order to achieve the above object, the present invention is characterized in that the bubble is extended along the boundary of the ion implantation transfer path. Therefore, the object of the present invention is as follows: (1) A pulse current is passed through a conductor pattern to stretch a bubble between different ion implantation transfer paths provided adjacent to each other at a predetermined interval. An element comprising a gate circuit having a function of forming a bridged bubble by being stretched like a string between the paths, wherein one of the ion implantation transfer paths is used as a means for stretching the bubble. (2) the spacing between the adjacently provided different ion implantation transfer paths; and (3) a magnetic bubble element in which the hairpin gap of the conductor pattern is arranged along the transfer path boundary portion where the bubble is stretched. This is achieved by

[Function] As is well known, the inner region of the transfer path is composed of a non-ion implantation region, and the outer region around it is composed of an ion implantation region. The boundary of this ion implantation transfer path (the boundary between the non-ion implanted region and the ion implanted region) has a low potential energy, so it is possible to stretch the bubble along the boundary with low energy, and this requires The operating pulse current can be very small.

The bubble stretched along the boundary of one transfer path is firstly stretched to the other adjacent transfer path, forming a bridge between the two transfer paths, but at this time, the bubble The shape of the transfer path is designed so that the end of the bubble is in close proximity to the other transfer path.As a result, by stretching the bubble by a small amount, it can be bridged to the other adjacent transfer path. It is possible to bridge with low energy. Therefore, the operating pulse current required for bridging to the other adjacent transfer path is as follows.

It requires low energy and requires very little Ist.

[Example] Hereinafter, an example of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a plan view showing the main parts of the gate circuit of the present invention. In this figure, the same symbols as in FIG. 2 indicate the same things.

First, the structure of the hairpin portion of a certain conductor pattern will be described. As shown in the figure, the structure of the groove (referred to as hairpin gap) in the hairpin part of the conductor 4o is along a part of the boundary of the ion implantation transfer path 30.
Furthermore, it is arranged to extend to a predetermined boundary between adjacent transfer paths to be bridged.

Next, regarding the positional relationship between two adjacent transfer paths, which is the second feature, the distance Q between the two transfer paths 2o and 30 that perform bubble bridging is shortened, and the bubble diameter d is reduced by 1
．． It has been reduced by 5 to 4 times.

The operation of bridging the bubble b at the point A on the transfer path 30 to the predetermined point B on the adjacent transfer path 2o is 1.
This is done in two steps as follows.

(1) First, by applying a pulse current to the conductor 40 for the bubble b transferred to the position of point A, the bubble b is stretched along the boundary of the transfer path 30. That is, the bubble b is stretched like a string along the groove in the hairpin of the conductor 40 from point A to point 0.

For the reasons mentioned above, the current value required for this operation is
Small values (approximately 40 to 100
mA) is sufficient. As a result 1, by the bubble stretching in the first stage of the present invention, the bubble b at point A is stretched from point A to point 0 along its boundary, and becomes like a string-like bubble b1.

(2) The string-shaped bubble b1 that has been stretched from point A to point 0 is then expanded to zero by the second stage of bubble stretching.
The bubble is extended from the point to the adjacent point B on the other transfer path 20 (a predetermined destination point where the bubble is finally extended). As a result, the bubble has two transfer paths 20 and 3.
0, and a string-like bubble b1
is formed by growing to bl-2.

Although it has been explained that the action of expanding the bubble b is carried out in two steps, the actual action does not proceed step by step, but by passing a predetermined dynamic current through the conductor 40, it is extended from point A to 0. A continuous string-like bubble is formed that extends from point B to point B.

The distance @12 between two adjacent transfer paths 20 and 30 is arranged to be 1.5 to 4 times the bubble diameter d, as described above. The distance Q of the slam was conventionally as large as about 10 times the bubble diameter d, but in the present invention it is considerably smaller as described above.

The energy required for the bridge decreases in proportion to the distance Q. When the distance Ω is large, two transfer paths 20.3
This is because the potential barrier that occurs between 0 and 0 becomes high. As a result, the pulse current value required for bridging from point 0 to point B is small and sufficient (50 to 100 +++ A).

Note that if the distance a is shorter than 1.5 times the bubble diameter, the bubble transfer characteristics of the transfer paths 20 and 30 will deteriorate. This is because if a simple bubble transfer operation is performed, a malfunction will occur in which the bubble is stripped out between points B and C. Therefore, the distance Q is desirably 1.5 times or more and 4 times or less the bubble diameter d.

In addition, in FIG. 1, the bridging operation of the bubble b from point A of the transfer path 30 to point B of the transfer path 20 was explained.
The present invention is also effective for bridge operation from point B to point A, and the operating current value can be similarly small. This is because the bridge from point B to point A is performed in two steps such as the first order.

First, the bridging operation can be completed by bridging from point B to point C and firstly extending from point 0 to point A along the transfer path boundary. This is because the energy required for these operations remains the same even in the opposite case.

In order to perform the bubble bridging operation, the conductor 40
As the pulse current waveform to be applied, a single pulse as illustrated in FIG. 3(a) or a double pulse as illustrated in FIGS. 3(b) and (c) can be used.

[Effects of the Invention] As described above, according to the magnetic bubble element equipped with the gate circuit of the present invention, the drive current value required for bubble bridging operation can be made much smaller than that of the conventional device.

[Brief explanation of the drawing]

Fig. 1 is a plan view of the main part of a gate circuit showing an embodiment of the present invention, Fig. 2 is a plan view of the main part of a conventional gate circuit, and Fig. 3 is a gate operating current used in the embodiment of the present invention. The waveform diagram and FIG. 4 are partially sectional plan views illustrating the basic configuration of the ion implantation transfer path. In the figure, 10.20,30...Ion implantation bubble transfer path 40...Conductor pattern Bu...Magnetic bubble HR...Rotating magnetic field Technique 2...Ion implantation area Fig. 1

Claims (1)

[Claims] 1. A string is created between different ion implantation transfer paths provided adjacent to each other at a predetermined interval by passing a pulse current through a conductor pattern to stretch a bubble. An element comprising a gate circuit having a function of forming a bridged bubble by being stretched into a shape, the device comprising a gate circuit having a function of forming a bridged bubble by extending the bubble along the boundary of one of the ion implantation transfer paths as means for stretching the bubble. A magnetic bubble element comprising a gate circuit provided with a portion where a bubble is stretched. 2. The magnetic bubble element according to claim 1, wherein the interval between the adjacently provided transfer paths of different ion implantation methods is 1.5 to 4 times the bubble diameter d. 3. The magnetic bubble element according to claim 1, wherein the hairpin gap of the conductor pattern is arranged along a transfer path boundary portion where the bubble is stretched.