JPH03165395A - Magnetic bubble memory element - Google Patents

Abstract

PURPOSE:To reduce heat generation caused by the current of a detecting line by enlarging the line width of a soft magnetic substance thin film detecting line near he crossing of a transfer path rather than the line width of the other soft magnetic substance thin film detecting line or arranging the detecting line while being divided into more than two lines. CONSTITUTION:A hair pin-shaped conductor 3 is provided to enlarge a magnetic bubble 2 on an ion injection transfer path 1 and a soft magnetic substance thin film detecting line 4 is provided to convert the leaked magnetic field of a stripe-shaped magnetic domain enlarging the magnetic bubble to an electric signal by utilizing a magneto-resistance effect. Width W2 of the detecting line 4 near the crossing of the transfer path 1 is enlarged rather than width W1 of the detecting line in the other area. Namely, the width W2 is set to 5 mum and the width W1 is set to 1.5 mum. Thus, a detector bias magnetic field margin can be almost equal to the bias magnetic field margin of the major line transfer path 1 and the common margin can be enlarged.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic bubble memory element using an ion implantation transfer path, and in particular, a magnetic bubble is expanded with a conductor pattern and detected with a soft magnetic thin film detection line. The present invention relates to a magnetic bubble memory device.

[Conventional technology]

A magnetic bubble memory element using an ion implantation transfer path uses a hybrid method in which the generator, gate, and detector are constructed using a soft magnetic transfer path, and these functional parts are constructed using a thin film for the conductor pattern and detection line. An ion implantation functional part method in which a soft magnetic material pattern is implanted is used.

The transfer path period of the minor loop section that stores information is 3 μm.
To make it less than 0.8 μm, it is necessary to use bubbles of 0.8 μm or less. In this case, since the characteristics of the soft magnetic material transfer path are insufficient, the ion implantation function method is more advantageous than the hybrid method.

A memory device detector using an ion implantation function is described in B.N.T.J. Vol. 59, No. 2, (1980).
) pages 229 to 257 (BSTJ
νoQ, 59. Nn2. (Feb. 1980
) pP229-257), and as shown in FIG. 3, a stretcher 3 composed of a hairpin type conductor that expands the magnetic bubble 2 on the ion implantation transfer path 1 and a magnetoresistive effect are utilized. The soft magnetic body detection line 4 converts the leakage magnetic field of the strip-shaped magnetic domain, which is an enlarged magnetic bubble, into an electric signal. magnetic bubble 2
is transferred on the ion implantation transfer path 1, and when present at the cusp 5, a pulse current 6 shown in FIG. 4 is applied to the stretcher 3.
By applying , the bias magnetic field in the hairpin conductor of the stretcher 3 is lowered, and the magnetic bubble 2 is expanded and changed into a strip-like magnetic domain. Strip-like domains extend within the loops of the hairpin conductor.

Then, the magnetization of the detection line 4 changes due to the leakage magnetic field of the strip-shaped magnetic domain. This change is 1 to 4 mA to the detection line 4.
By flowing a DC current of about 100 volts, it is possible to extract a voltage signal having an amplitude of several mV to several tens of mV using the magnetoresistive effect of the soft magnetic material. After the detection is completed, the elongated magnetic domain is reduced and returned to the original magnetic bubble 2 by removing the pulse current 6. For non-destructive reading, it is necessary to further transfer this magnetic bubble 2. In destructive reading, after removing the pulse current 6, a pulse voltage 7 in the opposite direction to the pulse current 6 shown in FIG. 4 is applied to cause the magnetic bubble 2 near the cusp 5 to disappear.

[Problem to be solved by the invention]

In the detector according to the prior art shown in FIG. 3, the detection line pattern 4 is arranged to cross over the cusp 5 of the ion implantation transfer path 1. By the way, since a direct current of several mA is constantly flowing through the detection line pattern 4, heat is generated due to Joule heat, and the temperature of the bubble garnet film under the detection line also rises due to this influence. For this reason, the bubble extinguishing and demagnetizing field (
Bubble material properties such as Ho) shift to the lower magnetic field side near the detection line. Therefore, the transfer characteristics of the magnetic bubbles that have reached below the detection line 4 shift to the low bias magnetic field side, causing a deviation from the bias magnetic field characteristics of other functional parts, resulting in a problem that the overall operating bias magnetic field margin decreases. Ta.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic bubble memory element that reduces heat generation in the vicinity of a detection line that intersects with an ion implantation transfer path and has a good overall operating bias magnetic field margin.

[Means to solve the problem]

The above objective can be achieved by making the detection line pattern width near the area intersecting the ion implantation transfer path larger than other parts, or by dividing the detection line near the area intersecting the ion implantation transfer path into two or more. be done.

[Effect]

The width of the detection line made of soft magnetic material in the vicinity intersecting the ion implantation transfer path is made larger than the width of other detection line regions. As a result, when a detection line current is applied, the current density in the area where the detection line width is increased is lower than in other detection line areas. Therefore, Joule heat in the region where the detection line width is increased is reduced compared to other detection line regions. Therefore, it is possible to reduce the temperature rise due to the influence of the detection line in the vicinity that intersects with the ion implantation transfer path, and the adverse effect on the bias magnetic field margin can be reduced. The other method is to divide the detection line made of soft magnetic material in the vicinity of the ion implantation transfer path into two or more parts. As a result, the detection line current flows in parallel to the detection lines in the vicinity that intersect with the ion implantation transfer path. Therefore, the current density in the detection line region near the intersection with the ion implantation transfer path is:
This can be reduced compared to other detection line areas. Therefore, it is possible to reduce the temperature rise due to the influence of heat generation in the vicinity of the detection line intersecting with the ion implantation transfer path, and to reduce the adverse effect on the bias magnetic field margin.

〔Example〕

Example 1 A first embodiment of the present invention will be described below with reference to FIG.

In the figure, this embodiment includes a hairpin type conductor 3 that expands a magnetic bubble 2 on an ion implantation transfer path 1, and a leakage magnetic field of a strip-shaped magnetic domain that expands the magnetic bubble using magnetoresistive effect, and converts it into an electric signal. Soft magnetic material detection line 4
It consists of Here, the width (W2) of the soft magnetic material detection line 4 in the vicinity intersecting the ion implantation transfer path 1 was made larger than the detection line width (Wl) in other areas. The detector is similar to the conventional detector shown in FIG. 3 except for the shape of the soft magnetic substance detection line.

Here, the width (W2) of the soft magnetic material detection line 4 in the vicinity intersecting the ion implantation transfer path 1 is set to 5 μm, and the detection line width (
Wr) was set to 1.5 μm. 0 of the detector in this case.
We investigated the bias magnetic field margin when using an 8 μm a magnetic bubble. The detection line current is 3 mA DC. In the case of a conventional detector as shown in Fig. 3, (soft magnetic material detection line width (W2) 1.5 μm), the bias magnetic field margin of the detector is compared to the bias magnetic field margin of the ion implantation measure line transfer path 1. , the amount by which the common margin is shifted due to the shift to the low bias magnetic field side by about 100e.

Decrease. On the other hand, the detector bias magnetic field margin of the above embodiment is as follows:
can be made almost equal to the bias magnetic field margin,
The common margin has been expanded compared to before.

Example 2 A second embodiment of the present invention will be described below with reference to FIG.

In this embodiment, the energization path of the soft magnetic material detection line 4 that intersects with the ion implantation transfer path 1 is divided into two. The detector is similar to the conventional detector shown in FIG. 3 except for the shape of the soft magnetic substance detection line. In this embodiment as well, good characteristics similar to those in Example 1 were obtained.

In addition, in this embodiment, the energization path is divided into two, but
A similar effect can be obtained by dividing into three or more.

〔Effect of the invention〕

According to the present invention, it is possible to reduce heat generation due to the detection line current of the soft magnetic material detection line in the vicinity of intersecting the ion implantation transfer path, so that a good overall operating bias magnetic field margin can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a magnetic bubble detector showing one embodiment of the present invention, Fig. 2 is a plan view of a magnetic bubble detector showing another embodiment of the invention, and Fig. 3 is a conventional magnetic bubble detector. FIG. 4 is a plan view showing the device, and FIG. 4 is a diagram showing the driving voltage pulse of the magnetic bubble memory element. 1. Ion implantation transfer path, 2. Magnetic bubble, 3.
hairpin type conductor, 4... soft magnetic body detection wire, 5...
... Cusp, 6... Stretch pulse current, 7... Annihilation pulse electric 'A'. Part 111■ Diagram and r Tomarizu and Gerikikasumi

Claims (1)

[Claims] 1. As a means of transferring magnetic bubbles, a transfer path is selectively formed under different ion implantation conditions from other parts, and a hairpin-shaped conductor pattern and soft wire are used to detect the magnetic bubbles transferred along the transfer path. Consists of magnetic thin film detection wire,
In the detector in which a portion of the soft magnetic thin film detection line intersects with the transfer path, the line width of the soft magnetic thin film detection line in the vicinity of intersecting the transfer path is greater than that of the other soft magnetic thin film. A magnetic bubble memory element characterized in that the soft magnetic thin film detection line, which is larger than the line width of the detection line or in the vicinity of intersecting the transfer path, is divided into two or more lines.