JPS6063785A - Magnetic bubble memory element - Google Patents

Abstract

PURPOSE:To obtain a magnetic bubble memory element of superhigh density which can stably act by setting the film thickness of the spacer layer to less than the specified value at least in the part of minor loop. CONSTITUTION:In the part of minor loop, a small magnetic bubble transfer route layer 14 having a film thickness of d2 is formed on the ion implantation layer 12. The film thickness of the conventional spacer layer is reduced to 1,000Angstrom or below, namely, the film thickness d1 of the spacer layer 13 is minimized (d1= 0Angstrom ). In other words, the spacer layer 13 is removed. By this condition, the dimension d2 between the magnetic bubble transfer route layer 14 and the ion implantation layer 12 is reduced, and the interaction of the transfer route layer 14 and the magnetic bubble is strengthened. Also by minimizing the film thickness d2, the anti-magnetic field coefficient becomes smaller and the transfer pattern becomes easy to be magnetized by rotation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to magnetic bubble memory devices, and in particular to storage capacitors.

[Background of the invention]

FIG. 1 is an enlarged plan view of essential parts of an example of a commonly used magnetic bubble memory element. In the figure, 1 is a minor loop that stores information, 2 is a read measure line that transfers read information, 3 is a write measure line that transfers write information, 4 is a magnetic bubble detector that converts magnetic bubbles into electrical signals, and 5 is a magnetic bubble generator that writes information on the write mesh line 3, 6 is a replicate gate that closes up the information on the liner loop 1 onto the read mesh line 2, and I is the information on the write mesh line 3 and the inside of the liner loop 1. 8 is a guardrail for preventing unnecessary magnetic bubbles from entering from the outer periphery, and 9 is a bonding pad for connecting these transfer circuits with external circuits.

Further, it is formed of a minor lube 1° lead measure line 2 and a write measure line Roy thin film batten 10, which are magnetic bubble transfer paths. And these bangs 10
is magnetized by an external magnetic field HR rotating within the batten plane, a moving magnetic bubble attracting magnetic pole is generated. In the figure, when the rotating magnetic field HR rotates counterclockwise υ, the magnetic bubble moves in the direction of arrow P. Transfer. In this case, when the rotating magnetic field HR rotates once, the magnetic bubble is transferred by one period λ of the baton 10. In addition, the figure (,) is called a half disk baton, the figure (b) is called an asymmetric chevron batten, and the figure (C) is called a wide gap batan.
It has been most commonly adopted in recent years. Further, the magnetic bubble transfer path of such a transfer method is called a half-loy drive method, and this is also commonly employed. The magnetic bubble memory element of the present invention also uses this method.

In recent years, in order to realize high-density magnetic bubble memory elements,
The bang period λ of the magnetic bubble transfer path used is miniaturized,
The magnetic bubble diameter d used for this has also become smaller and is currently 1
M-bit magnetic bubble memory devices have been put into practical use.

The magnetic bubble diameter d used in this element is approximately 2 μm, and the period λ of the minor loop transfer path bang is 7 to 8.
In this case, the storage density is IMb/, +2
It is.

Recently, various fields have been demanding the realization of so-called ultra-high-density magnetic bubble memory devices with even higher storage densities. For example, the magnetic bubble diameter d used is 1.0 to 1.0.
5 μm, and the transfer path slam period λ is 4 to 6 μm.
b li magnetic bubble memory device implementation. However, in order to realize such an ultra-high-density magnetic bubble memory element, it is difficult to form a magnetic bubble memory element that operates stably and satisfactorily by simply proportionally reducing the battens of the conventional magnetic bubble memory element. However, a sufficiently wide bias field margin could not be obtained.

[Purpose of the invention]

Therefore, it is an object of the present invention to solve the above-mentioned problem by W (never,
An object of the present invention is to provide an ultra-high density magnetic bubble memory element that can operate stably.

[Summary of the invention]

To achieve this purpose, the magnetic bubble memory element based on the non-explosion j has a spacer layer having a film thickness of 100 OA or less at least in the inal loop portion.

Generally, in order to increase the density of magnetic bubble memory elements, when the period λ of the transfer path pattern in the minor loop section is reduced,
The following problems occur: That is, (1) the demagnetizing field coefficient of the transfer path pattern increases in inverse proportion to the period λ of the transfer path pattern in the minor loop portion.

(2) The reassuring strength of the rotating magnetic field HR used to magnetize the permalloy transfer path pattern to transfer magnetic bubbles increases in proportion to the demagnetizing field coefficient.

(3) The strength of the rotating magnetic field HR cannot be increased due to the restriction of consumed core force, and is therefore insufficient.

(4) As a result, the bias magnetic field margin decreases in proportion to the transfer path slam period λ.

In order to solve this problem, it is sufficient to reduce the demagnetizing field coefficient of the transfer path. However, there are limits to reducing the demagnetizing field coefficient due to theoretical constraints.

Therefore, in order to solve the above problems, the present invention aims to strengthen the interaction between the permalloybatan and the transferred magnetic bubbles, which are magnetized by a rotating magnetic field. It is distinctive in that it is virtually zero.

FIG. 3 is a cross-sectional configuration diagram of a main part of a minor lube portion of a conventional magnetic bubble memory element. In the figure, 11 is a bubble magnetic film serving as a magnetic bubble medium, 12 is a magnetic film 110 (8
13 is a spacer layer formed of 5i02 etc. on the ion implanted B'112, 14 is a permalloy etc. layer formed on the spacer layer 13. The magnetic bubble transfer path layer 15 of the formed minor loop portion is formed on the transfer path 14 by S10. This is a protective film layer formed by et al.

In this case, the film thickness d1 of the spacer layer 13 is 2500A to 6
000 k, and the film of the transfer path layer 14) d2 [Embodiments of the Invention] Next, embodiments of the present invention will be described in detail with reference to the drawings.

Figure 4 shows a magnetic bubble memo according to the present invention! This is a cross-sectional configuration diagram of a main part of a minor loop portion corresponding to the above-mentioned FIG. 3 showing an example of J element C+-, and the same parts as in FIG. 3 are given the same symbols. In the figure, a magnetic bubble transfer path layer 14 having a small thickness d2 is formed on the ion implantation layer 12. That is,
The film thickness d1 of the spacer layer 13 shown in Figure @3 is 100OA.
Below, that is, the film thickness di of the spacer layer 13 is set to the minimum (d1=
OA), in other words, the spacer layer 13 is eliminated.

According to such a configuration, the dimension dz between the magnetic bubble transfer path layer 14 and the ion implantation layer 12 is small, and therefore the interaction between the magnetic bubble transfer path RiJ14 and the magnetic bubbles is strengthened. Furthermore, by reducing the film thickness d2 of the magnetic bubble transfer path 14, the demagnetizing field coefficient becomes smaller, making it easier to be magnetized by rotation of the transfer button.

FIG. 5 is a diagram showing the effect of the embodiment of the magnetic bubble memory element according to the present invention, in which the film thickness d2 of the magnetic bubble transfer path layer 14 in the aforementioned minor loop portion is set to 100 OA, and the film thickness di of the spacer layer 13 is made small. Bias magnetic field margin width ΔHB (chi) of the minor loop bubble transfer characteristic when
This shows the results obtained experimentally. In the figure, if the film thickness d1 is set to 100 OA or less, which is substantially dl:o, a sufficiently large force ΔHB margin can be obtained.

Note that when the film thickness dl=OA, the spacer layer 13 is omitted, so that the manufacturing process of the magnetic bubble memory element can be simplified.

FIG. 6 is a diagram showing the effect of another embodiment of the magnetic bubble memory element according to the present invention, in which the film thickness d! of the spacer layer 13 in the aforementioned minor loop portion is ! Bias magnetic field margin width ΔHB (
%) is shown experimentally. In the figure, the film thickness d2 of the magnetic bubble transfer path layer 14 is 2000A.
If it is set below, a sufficiently large ΔHB margin can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, by reducing the thickness of the spacer layer in the minor loop portion, a sufficiently large ΔHB margin can be obtained, so that a high-density magnetic bubble memory element with high operational stability can be obtained. Furthermore, by reducing the thickness of the spacer layer and the thickness of the magnetic bubble transfer path layer at the same time, an even larger ΔHB margin can be obtained, making it possible to realize a high-density magnetic bubble memory element with even higher operational stability. You can get extremely excellent effects such as:

[Brief explanation of the drawing]

Figure 1 is an enlarged plan view of essential parts showing an example of a magnetic bubble memory element, Figures 2 (a), (b), and (c) are enlarged plan views showing examples of magnetic bubble transfer path slams, and Figure 3 is a magnetic FIG. 4 is a cross-sectional diagram of the main part of the minor loop part of the bubble memory element, FIG. 4 is a cross-sectional diagram of the minor loop part showing an example of the magnetic bubble memory element according to the present invention, and FIGS. 5 and 6 are diagrams showing the magnetic bubble according to the present invention. FIG. 3 is a diagram illustrating the effect of a memory element. DESCRIPTION OF SYMBOLS 1... Minor lube, 11... Magnetic bubble magnetic film, 12... Ion implantation layer, 13... Spacer layer, 14... Magnetic bubble transfer path layer, 15...・Protective film layer. Figure 1 Figure 2 Figure 3? □ Fig. 5 0 1000 2000 3000 4000 Matata - Sakanjyu d+f included)

Claims (1)

[Claims] 1. A magnetic bubble memory element formed by forming an ion implantation layer tb on the surface of a magnetic bubble magnetic film, and further laminating a spacer layer and a magnetic bubble transfer path layer on this ion implantation layer in sequence. 2. A magnetic bubble memory device according to claim 1, wherein the spacer layer has a thickness of 100 OA or less at least in the minor loop portion. 2. Claim 1, characterized in that the thickness of the spacer layer is zero at least in the minor loop portion.
The magnetic bubble memory device described in . 3. The magnetic bubble memory device according to claim 1, wherein the thickness of the magnetic bubble transfer path layer in the minor loop portion is 2000 Å or less.