JPS6244354B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a transfer gate in a magnetic bubble device having a major minor loop configuration formed by an ion implantation process.

Conventionally, magnetic bubble devices have been put into practical use using a permalloy transfer pattern method using a garnet film as a memory substrate, but since the recording density was limited to 1 Mbit/cm ² , an even higher capacity was required, and 4 Mbit/cm was required. ²
A device has been developed that transfers, reads, and writes bubbles (referred to as transfer) by forming a desired pattern on a garnet film using ion implantation technology that enables bubble transfer.

There are various patterns that can be adopted for bubble devices, but currently the most typical example is a contiguous disk bubble device (CDD) that uses a continuous beaded disk pattern.
An overview will be given using the Disk Bable Device as an example.

It is generally known that when a magnetic thin film bubble crystal such as a garnet film is covered with a resist or an Au vapor-deposited film to form a disc-shaped pattern with ion implantation, bubbles are attracted to the periphery of the disc-shaped pattern. ing. As shown in FIG. 1, when an in-plane rotating magnetic field (hereinafter simply referred to as a rotating magnetic field) is applied to adjacent beaded disk patterns 1 of the disks, the bubbles move along the periphery of the beaded disk patterns 1. In such a magnetic thin film, there are axes that are easily striated out at 120° intervals in three directions, and the above-mentioned bead-shaped disk pattern 1 is applied to these easy magnetization axes that are 120° apart. Depending on which direction the disk patterns to be formed are lined up in a row, there are three bubble movement paths: super track S, butt track b, and good track g.

Here, super track S refers to the relationship between the _K1 direction of the magnetic thin film bubble crystal and the traveling direction of the transfer path as shown in Figure 1, and is a transfer path that is generally said to have a large bias margin. This is the path through which bubbles are easily transferred. Bud track b is a transfer path where the bias margin is said to be the smallest based on the relationship shown in FIG. 1, and it is a path in which bubbles are difficult to be transferred. Good track g is a path with intermediate operating margin for bubble transfer. As shown in FIG. 1, the path on the opposite side to the super truck S becomes a butt truck b. Furthermore, all paths of the continuous bead-shaped disk pattern 1 in the _K1 direction of the magnetic thin film bubble crystal are good tracks g. This is because the peculiarity of bubble transfer appears due to the magnetocrystalline anisotropy of the magnetic thin film bubble crystal.

FIG. 2 is a principle diagram explaining the basic operating principle of a cascading disk pattern transfer path having a super track S and a Bud track B, in which 2-1 to 2-8 are disk patterns, and 3 is a transfer path. The transfer path pattern 3 includes adjacent disk patterns of four disk patterns 2-1 to 2-4 and four disk patterns 2-5.
It is assumed that 2 to 8 adjacent disk patterns form a chain-shaped disk pattern arranged in a row with a gap in between. The relationship between these disk patterns 2-1 to 2-8 and the magnetic thin film is such that the lower bubble path of the disk patterns 2-1 to 2-8 is the super track S, and the upper bubble path is the super track S. Butt truck b
It is configured so that. 4 is a bubble, which is the transfer path pattern 3 before applying the rotating magnetic field.
The bubble exists in the super track S of the transfer path pattern 3, but as the rotating magnetic field is applied, the bubble is transferred as shown in 4'. 5' as the rotating magnetic field is applied.
represents a bubble transferred to super track S as shown in FIG. Note that K ₁ in the same figure represents the direction of the easy axis of magnetization with respect to the disk pattern of a magnetic thin film bubble crystal, such as a garnet film.

As shown in FIG. 2, when a bubble 4 exists in the path below the disk pattern 2-1 of the transfer path pattern 3, that is, in the super track S, when a rotating magnetic field is applied in the counterclockwise direction, the bubble 4 is transferred one bit at a time to adjacent disk patterns 2-2 and 2-3 each time the rotating magnetic field rotates once, and by repeating this process, bubble 4 is transferred to disk pattern 2-3. The bubble 4 transferred to the disk pattern 2-3 moves along the periphery of the disk pattern 2-4 with the rotating magnetic field of the next cycle, but the bubble 4 rotates once and moves around the disk pattern 2-4. It does not rotate to the upper path or bud track b, but is transferred across the gap to the next disk pattern 2-5 by the application of the rotating magnetic field. In this way, super
Even if there is a gap between the disk patterns, the bubble on the track S has the property that if the width of the gap is within a predetermined gap, the bubble will be transferred on the super track S across the gap. Then, as the rotating magnetic field is applied, the bubble 4 moves and is transferred to the bubble 4'.

On the other hand, the bubble 5 existing in the upper path of the disk pattern 2-6, that is, the butt track b.
When a rotating magnetic field is applied in a counterclockwise direction, the bubble 5 is transferred to the adjacent disk pattern 2-5. Then, when the next cycle of rotating magnetic field is applied, the bubble 5 cannot cross the gap,
Disk pattern 2-5 as shown by the broken line in Figure 2
Super Truck S rotates along the periphery of
will be introduced in Then, as the rotating magnetic field is applied, the bubble 5 is transferred on the super track S and moves to the bubble 5'. In this way, when there is a predetermined gap between the disk patterns in the transfer path pattern 3, the bubble 4 on the super track S is transferred across the gap, whereas the bubble 5 on the butt track b is transferred. has the property of not being able to cross the gap, but moving along the periphery of the disk pattern and being introduced into the super track S.

Transfer gates for writing from the major loop to the minor loop or reading from the minor loop to the major loop of a conventionally known magnetic bubble device having a cascade-shaped disk pattern transfer path can be broadly classified into the following types: It can be divided into two types. The first one is shown in Figure 3.
Assuming that the information bubble 7 is being transferred from the left to the right on the lower transfer path of the loop transfer path 6, that is, the super track S, when the bubble 7 reaches a predetermined position, the medium loop A pulse current is applied to a hairpin-shaped conductor pattern 9 that transfers between the transfer path 6 of the transfer path 6 and the transfer pattern (transfer path) 8 of the minor loop that stores information, and the bubble 7 is connected to the hairpin-shaped conductor pattern 9. and is transferred to transfer pattern 8 of the minor loop. That is, information is written to the minor loop. At this time, the bubble 7 extends across the major loop transfer path 6, in other words, across the major loop pattern and is transferred to the minor loop transfer path 8, so a large pulse is generated in the conductor loop of the hairpin conductor pattern 9. The disadvantage is that current must flow through it.

In addition, charged wall assist tends to cause bubble nucleation, which has the disadvantage of reducing the current margin in the transfer process. Furthermore, there is a drawback that the bias margin is small.

The second transfer gate has the configuration shown in FIG. 4, and has a striped conductor 12 between the major loop transfer path 10 and the minor loop transfer pattern 11, and the information bubble 1.
3 reaches a predetermined position, a pulse current is applied to the strip-shaped conductor 12, and the magnetic field gradient causes the bubble 13 to be transferred to the transfer path 10 of the major loop.
The data is transferred from the upper path, ie, the super track S, to the transfer pattern 11 of the minor loop and written. At this time, the bubble 13 does not need to cross the butt track b of the transfer path 10 of the major loop, but when reading, the position of the bubble transferred from the transfer pattern 11 of the minor loop to the transfer path 14 of the major loop. is read out to the lower path of the transfer path 14 of the medium loop, ie, the butt track b, via the conductor 15, which has the drawback that the time sequence of writing and reading is reversed.

The present invention aims to provide a magnetic bubble device which improves the above-mentioned drawbacks, and its object is to provide a magnetic bubble device which is formed by a non-ion implanted region formed in an ion implanted region on a magnetically anisotropic crystal thin film.・It has a loop and a minor loop, and has a minor loop.
In a magnetic bubble device, the edges of the loops are oriented in a direction forming a good track, and the major loops are oriented close to both ends of the minor loop in a direction perpendicular to the minor loop, The butt track side divides the major loop facing the minor loop at the opposing position, and has an extension pattern extending in the direction of each minor loop from the division position, and the extension pattern and each minor loop are opposite to each other. This can be achieved by a gate structure of an ion implantation bubble device characterized in that it has a conductor path extending through the gap in the direction of the above-mentioned mean loop.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 5 is a circuit diagram of an embodiment of a conventional device.

In the figure, write transfer gate 2
5 is composed of a hairpin type conductor 23,
Read transfer gate 26 is 12 in FIG.
N is a modification of the striped conductor shown in
It is composed of mold conductors 24, the detailed structure and operation of which are as described above.
To add more information about the overall circuit configuration, the medium loop 16-2 in the write transfer gate 26 is connected to the magnetic bubble 2 by the generator 30.
0, read transfer gate 26
The measure loop 16-1 performs a read or erase operation in the stretcher detector 40.

In the figure, what is particularly noteworthy is the
Loops 16-1 and 16-2 are super track S
is placed at the bottom of the figure, and the butt track B is placed at the top. In addition, the mejiya in the same figure
The pattern of track 16-2 is called a snake pattern, which is a modification of the cascading disc pattern, and its operation is the same as that of the cascading disc pattern. Also, Maina Loop 17-1…
...17-N is a good track. G is a good track.

The configuration in the figure is the arrangement 60 of the axis of easy magnetization of the magnetic thin film.
This is determined because the three axes _K1 are formed into an equilateral triangle as shown in the figure.

Further, the magnetic field rotation direction 50 of the (in-plane) rotating magnetic field is counterclockwise.

FIG. 6 is a circuit diagram of an embodiment of the present invention.

If the easy magnetization axis _K1 is arranged in an inverted triangle as shown in the arrangement 60 of easy magnetization axes in the same figure, if the major loop is arranged in the horizontal direction and the minor loop is arranged in the vertical direction in the figure, the・The loop has a super track on the upper side and a bad track on the lower side, and the minor loop has a good track.

In this embodiment, in the arrangement shown in the figure, the minor loop 17-1 is arranged in the major loop 16-1.
_{The major loop 16-1 is divided at positions X 1 ,} Patterns Y ₀ , Y ₁ , Y ₂ .・Configures the gate 26.

As shown in the figure, in this read transfer gate 26, the minor loop 17 (1 to
The transfer-out operation of the bubble from N) is
Between the good track and the good track (between extended patterns Y ₀ , Y ₁ , Y ₂ ...... and the minor loop)
Since this is carried out in the same manner, the operation margin is expanded and the circuit operation becomes stable.

The bubble operates as an N-type conductor in this example, but as described above in the striped conductor (Fig. 4-1).
Since it is the same as that in 2), the explanation will be omitted.

Note that the rotating magnetic field is clockwise as shown in the magnetic field rotation direction 50 in this example.

In this example, read transfer gate 2
5 and readout transfer gate 26 are both N-type conductors, but the gate structure of the present invention is applicable to any hairpin type or other suitable conductor for configuring each gate.

As described above, the present invention allows a large operating margin of the read transfer to be achieved by a simple process of connecting a part of the minor loop to a part of the major loop, thereby increasing the overall margin of the entire device. , the stability of bubble operation is also improved.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram explaining the relationship between the crystal direction of the magnetic thin film bubble crystal and the transfer path, and Figure 2 is an explanatory diagram explaining the relationship between the crystal direction of the magnetic thin film bubble crystal and the transfer path.
An explanatory diagram illustrating the basic operating principle of a cascading disk pattern transfer path having a track S and a butt track B. FIGS. 3 and 4 show a conventional write/read transfer in a cascading disk pattern transfer path. Gate: FIG. 5 is a circuit configuration diagram of an embodiment of a conventional device, and FIG. 6 is a circuit diagram of an embodiment of the present invention. In the figure, 16-1 and 16-2 are medium loops,
17-1 to 17-N are minor loops, 18
is a gap, 20, 20A, 20B is a bubble, 2
1 is a stretched bubble, 22, 22C, 22D
is a cusp, 23 is a hairpin conductor, 24 is an N-type conductor, 24A is a repulsion section, 24B is an attraction section, 25 is a write transfer gate, 26 is a read transfer gate, 30 is a generator, 40 is a stretcher detector , 50 is the magnetic field rotation direction, 60 is the arrangement of the easy magnetization axis, _K1 is the easy magnetization axis, B and b are the butt tracks, G and g are the good tracks, and S is the super track.

Claims (1)

[Claims] 1 It has a major loop and a minor loop formed by a region where ions are not implanted in the ion implanted region on the magnetically anisotropic crystal thin film, and the edge of the minor loop is a good track. In a magnetic bubble device, the major loop is located close to both ends of the minor loop and is located in a direction perpendicular to the minor loop. is divided at the opposing position, an extension pattern extending from the division position in the direction of each minor loop, and a conductor path extending in the direction of the major loop through the opposing gap between the extension pattern and each minor loop. A gate structure of an ion implantation bubble device characterized by the following characteristics: