JPH0376088A - Ion implanted magnetic bubble memory element - Google Patents

Abstract

PURPOSE:To prevent the malfunction by placing a hair pin conductor pattern for dividing a strip magnetic domain formed by enlarging a bubble, roughly in parallel to a bubble enlarging hair pin in the vicinity of the part in which a strip magnetic domain division is generated. CONSTITUTION:A bubble dividing conductor pattern 5 is provided by placing a layer insulated electrically from a bubble enlarging conductor pattern 4 between. The conductor pattern 5 has an area 8 whose gap is narrow, and also, the area 8 whose gap is narrow is placed adjacently to a hair pin gap 7 formed by the conductor pattern 4, that is, so as to be in a distance of <=1mum, and also, the conductor patterns 4, 5 are placed so as to become roughly parallel to each other in the vicinity of the hair pin gap 8. In such a way, such a malfunction as the divided strip magnetic domain expands or moves in the unnecessary direction can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a gate (hereinafter abbreviated as dual gate) having a magnetic bubble replicating and swapping function, which is constituted by an ion implantation transfer path and a conductor pattern.

[Conventional technology]

A replicate gate using an ion implantation transfer path and a two-layer conductor pattern is described in Japanese Patent Application Laid-Open No. 58-14.
As shown in No. 6086, a method is used in which a magnetic bubble on a minor loop corner is extended by a hairpin-shaped conductor pattern and divided by two parallel conductors. Further, a dual gate which is an improved version of this replicate gate and has a swap gate function is disclosed in Japanese Patent Laid-Open No. 62-262293.

[Problem to be solved by the invention]

In the replicate gate 3 and dual gate 3 according to the prior art described above, as shown in FIGS. 2 and 3, the hairpin conductor pattern 5 or two parallel conductor patterns 5 that divide the strip magnetic domain extend the bubble. It is almost perpendicular to the hairpin conductor pattern 4.

If the stretch conductor 4 and the split conductor 5 are perpendicular to each other in this way, the malfunction shown in FIG. 4(c) becomes a problem. As shown in FIGS. 4(a) and 4(b), the strip magnetic domain 6, which is elongated by lowering the bias magnetic field of the hairpin gap 7 by applying a bubble expansion pulse to the stretch conductor 4, is transferred to the strip magnetic domain dividing conductor 5. By increasing the bias magnetic field of the hairpin gap 8 by applying a dividing current pulse to the strip magnetic domains 6-1 and 6-2,
Divide into.

In the region where the amplitude of the current pulse for splitting is larger than the minimum value required for splitting, or near the limit of the operating bias magnetic field margin, the strip magnetic domain 6 after splitting as shown in Fig. 4(c) is A malfunction occurs in which -1.6-2 extends along the dividing conductor pattern 5. This malfunction occurs because the bias magnetic field becomes high in the gap 8 part of the dividing conductor pattern 5 when a current pulse is applied, but there is a region outside the gap 8 where the bias magnetic field becomes low when a current pulse is applied. One way to prevent malfunctions is to change the pulse width of the current pulse for strip magnetic domain division from the currently used 100 to 150 ns to 2.
A method of narrowing the time to 0 to 30 ns is effective. That is,
By increasing the bias magnetic field in the gap 8 portion for a short period of time required for division, subsequent malfunctions in elongation of the strip magnetic domain are prevented.

Since the speed at which the strip magnetic domain extends is 20 to 50 m/s, a current pulse of 20 to 30 ns will extend the speed of 0.4 to 1
．． Since the strip magnetic domain extends only by 5 μm and 8 degrees, malfunctions can be prevented.

However, when such a current pulse with a narrow pulse width is used, the following two problems arise.

The first problem is that when the amplitude of the current pulse for strip magnetic domain division is 100 ns to 150 ns,
A, whereas in 20 to 30 ns, the problem becomes as large as 300 mA. This means that the time required for narrowing the width of a part of the strip magnetic domain 6 during the dividing operation is
This is because it depends on the amplitude of the current pulse.

The problem with AA batteries lies in the current pulse drive circuit.

In a circuit that generates a current pulse with a pulse width of 20 to 30 ns, the rise and rise times need to be as short as about Ions, so the cost of the circuit is higher than in the case of a pulse width of 100 to 150 ns. .

In the present invention, the pulse width of the dividing current pulse is 100 to 150.
It is an object of the present invention to provide a replicate gate or a dual gate that does not cause a malfunction in which the strip magnetic domain 6 extends immediately after being divided by one even if it is as large as ns.

[in! Means to solve one problem] Above &! In order to achieve this purpose, a hairpin conductor pattern 6 or a parallel conductor pattern 5 for dividing the strip magnetic domain 6 in which the bubble has been expanded is arranged almost parallel to the bubble expansion hairpin in the vicinity of the part where strip magnetic domain division occurs. It is.

[Effect]

In the magnetic bubble splitting operation, first, a current pulse is passed through the hairpin conductor pattern 4 for bubble expansion to lower the bias magnetic field of the hairpin gap 7, thereby separating the magnetic bubbles existing on the corner pattern of the minor loop 1 or on the noja line 2. is extended inside the hairpin gap 7 to form a strip magnetic domain. Next, a current pulse is applied to the conductor pattern 5 for strip magnetic domain division,
By increasing the bias magnetic field at the narrow gap portion 8 of the dividing conductor pattern 5, the strip magnetic domain extending into the hairpin gap 7 is divided into two strip magnetic domains. In this dividing operation, a magnetic field pulse generated by a current pulse applied to the dividing conductor pattern is applied in a direction that increases the bias magnetic field inside the hairpin gap 7, that is, in the region where the elongated strip magnetic domain exists. Therefore, the divided strip magnetic domains only contract in the vertical direction, and do not move to the outside of the hairpin gap 7 where the bias magnetic field is focused, or extend in unnecessary directions, resulting in malfunction.

〔Example〕

(Example 1) A first example of the present invention will be described using Figure 1. The gate of this embodiment is a gate having the function of a replicate gate, and is an improved version of the conventional replicate gate shown in FIG. A hairpin conductor pattern 4 for bubble expansion is provided at the tip part 9 of the corner pattern of the minor loop 1 and the cusp 10 of the major line 2 so that the gap thereof overlaps. A bubble splitting conductor pattern 5 is provided with an electrically insulating layer sandwiched between the bubble expanding conductor pattern 4 and the bubble expanding conductor pattern 4. The conductor pattern 5 has a narrow gap region 8 and the narrow gap region 8 is arranged close to the hairpin gap 7 formed by the conductor pattern 4 . Further, the conductor patterns 4.degree. 5 are arranged so as to be substantially parallel to each other in the vicinity of the hairpin gap 8.

The bubble splitting operation of this gate starts by passing a current pulse for bubble expansion through the hairpin conductor pattern 4 to expand the bubble within the hairpin gap 7. The elongating magnetic bubble is present either at the cusp lO of the magger line 2 or at the corner tip 9 of the minor loop l. Both ends of the strip magnetic domain expanded by the bubble expansion current pulse exist at the tip 9 and the cusp 10. In this state, a current pulse for dividing the strip magnetic domain is passed through the conductor pattern 5. This current pulse generates a magnetic field pulse that increases the bias magnetic field at the gap 8, and the strip magnetic domain is divided into two.

In this dividing operation, the magnetic field applied to any part of the strip magnetic domain is in the direction in which the bias magnetic field becomes stronger, so there is no malfunction in which the strip magnetic domain extends in an unnecessary direction as in the conventional example.

(Example 2) A second example of the present invention will be described using FIG. 5. This embodiment is an improvement of the dual gate bubble erasing and bubble splitting conductor pattern 5 shown in FIG. A hairpin conductor pattern 4 for bubble expansion is used in which the gap spans between the corner tip 9 of the minor loop 1 and the cusp 10 of the mager line 2.

The pattern shape of this conductor pattern 4 is almost the same as the dual gate shown in FIG.

In the dividing and erasing conductor pattern, as in the first embodiment, the gap width is narrowed only in the vicinity of the gap 8 that divides the strip magnetic domain. Further, the stretch conductor and the dividing and erasing conductor pattern are approximately parallel to each other in the vicinity of the gap 8. Minor loop 1
A part of the conductor pattern 5 is bent to form a hairpin in order to eliminate magnetic bubbles in a pseudo-swap operation on the corner pattern of the conductor pattern. In other parts, the pattern width is partially widened in order to prevent other magnetic bubbles on the transfer path from being influenced by the magnetic field created by the conductor pattern during bubble erasure and strip magnetic domain division.

The operation of the gate in this embodiment is the same as in the first embodiment except for erasing bubbles during the pseudo-swap operation.

During the replicate operation, a current pulse is passed through the hairpin conductor pattern 4 in a direction in which the bias magnetic field of the hair gap 7 is lowered, thereby elongating the magnetic bubble present on the tip 9 of the minor loop corner and forming a strip magnetic domain. Subsequently, a dividing current pulse is passed through the dividing conductor pattern to increase the bias magnetic field in the gap 8, thereby dividing the strip magnetic domain into two.

In this operation, the bias magnetic field in the region where the strip magnetic domain exists only becomes stronger, and the strip magnetic domain does not unnecessarily elongate or move.

In the pseudo swap operation, first, the magnetic bubble on the minor loop corner is erased by the annihilation hairpin portion 11 of the conductor pattern 5 by applying a current pulse. Subsequently, a current pulse is applied to the hairpin conductor pattern 4 to further extend the magnetic bubble corresponding to the write data existing at the cusp 10 of the mager line 2 to form a strip magnetic domain. Subsequently, a current pulse is passed through the conductor pattern 5 to strengthen the via nonmagnetic field in the gap 8 and divide the strip magnetic domain into two. This operation is similar to the case of replication.

〔Effect of the invention〕

According to the present invention, it is possible to prevent malfunctions in which the divided strip magnetic domains extend or move in unnecessary directions due to the pulsed magnetic field generated by the current pulse flowing through the conductor pattern for strip magnetic domain division of the ion implantation element. This has the effect of increasing the amplitude and pulse width margins of the current pulse required for the operation of the replicate gate or dual gate of the implanted element.

[Brief explanation of drawings]

1 and 5 are plan views of the main parts of a magnetic bubble memory element showing an embodiment of the present invention, FIG. 2 is a plan view showing a conventional replicate gate, and FIG. 3 is a plan view showing a conventional dual gate. FIG. 4 is a plan view showing a malfunction during bubble division in a conventional replicate gate and dual gate. l... Minor loop, 2... Major line, 3.
... Minor loop corner, 4... Hairpin conductor pattern for bubble expansion, 5... Conductor pattern for dividing and erasing, 6... Magnetic bubble, 7, 8... Gap portion, 9... Minor loop corner. tea diagram

Claims (1)

[Claims] 1. At least a first hairpin conductor pattern is provided between the ion implantation transfer path constituting the major line and the ion implantation transfer path constituting the minor loop, and the first hairpin conductor pattern is substantially parallel to the first hairpin conductor pattern;
An ion implantation magnetic bubble memory element having a gate having a portion within 1 μm from a first hairpin conductor pattern, and including two conductor patterns insulated from the first hairpin conductor pattern. .