JPS5826386A - Bubble magnetic domain element - Google Patents

Abstract

PURPOSE:To improve the bubble transfer characteristics and the like, by constituting the shpae of the transfer pattern of bat tracks as a specified shape. CONSTITUTION:In a contiguous disc element which transfers bubbles with a magnetic charge wall of an inter-plane magnetizing layer on a bubble storage layer along the pattern, a transfer pattern in a pitch P of a bat track orthogonal to an axis of difficult magnetization 11 in the plane and located at the side of the axis is formed that an angle 15 between the leading this side of the top to the progressing direction of a bubble 17 and the axis 11 is taken as about 30 deg., which is smaller than the angle 16, about 60 deg., between the other leading and the axis 11. Through this shape, the transfer margin can be improved and the bubble transfer characteristics can be progressed. Further, since two sets of large and small patterns are not used, the design of the constitution of function can be made easy and the error in tansfer can be decreased.

Description

[Detailed Description of the Invention] The present invention is based on Bubble! This invention relates to a bubble (hereinafter simply referred to as a bubble) element.

Conventionally, bubble devices have adopted a method in which soft magnetic patterns are provided on a bubble retaining layer with a gap between them and bubbles are transferred by in-plane 4+n field rotation.

However, the gaps in the above pattern reduce the bubble density,
This is unfavorable because it poses an obstacle to high-speed bubble transfer and limits pattern microfabrication.

On the other hand, U.S. Pat. No. 3,828,329 proposed an element that transfers bubbles using a gapless pattern, and its development has been progressing rapidly recently.

There, the pattern is formed by ion implantation. Since the transfer pattern of that device was in the shape of a series of circles, it is known as a contiguous disk (hereinafter referred to as CD) device, including devices with shapes developed later.

In this CD element 61, an in-plane magnetization layer is provided on the bubble retention layer, and within the in-plane magnetization 1☆ (1;
rgedwa11) to transfer the bubble. Since this in-plane magnetization layer has itB normal crystal anisotropy, C
IEI Transactions on Magnetism (IEI Trans, Ma
gn, ) j (lJiag-Volume 15 (1979) No. 1
As stated on page 323 (hereinafter referred to as the document),
A) Characteristics that transfer differs depending on the crystal plane orientation of the transfer path.

In particular, the transfer path perpendicular to the in-plane hard magnetization axis and on the side of the hard magnetization axis is a pad (bad l-rack), and the transfer path on the opposite side is a super (5ttpQr-) track, which is parallel to the in-plane hard magnetization axis. The transfer paths are respectively called goucj and l-racks, and it is known that bubble transfer is worst in pad tracks and good in super tracks. For C1) elements, good tracks and super tracks are mainly used, but the poor transfer characteristics of pad tracks become an obstacle to the functioning of CI) elements.

An example of a r9-optimized attempt at pad track transfer is the roof-tr+p pattern in the above-mentioned document.

However, in the roof I/Wave pattern, small pattern elements and large pattern elements are arranged alternately, so the design of the structure is strange, and the large pattern has many transfer points. Zoni remains. However, at present, no other effective reformation method is known.

An object of the present invention is to provide an element having a pattern shape that improves bubble transfer characteristics.

According to the present invention, in a CD element in which an in-plane magnetization layer is provided on a bubble retaining layer to form a transfer pattern, bubbles are transferred along the pattern from the in-plane (+a) back wall of the in-plane magnetization layer. Of the two rising parts that are perpendicular to one in-plane hard magnetization axis and sandwich the apex of the pattern element of the transfer path on the hard magnetization axis side, the rising part on the near side of the apex with respect to the bubble traveling direction and the above A bubble element is obtained in which the angle made with the hard magnetization axis is smaller than the angle made with the 4E hard magnetization axis of the other rising portion.

Hereinafter, the present invention will be explained in detail with reference to examples.

Example 1゜ FIG. 1 shows an example of a transfer pattern of the present invention.

Here, the direction of the black circle around the 11th left 9111 circle is 11.
12.13 indicates the in-plane hard magnetization axis. That is, the pattern elements are arranged in a transfer path perpendicular to one hard magnetization axis 11 in the plane and on the 11 side. As shown in Figure 1, the period P
Of the two rising parts sandwiching the apex 14 of the transfer pattern (shaded area), the rising part on the hand cup side of the apex and the magnetization with respect to the traveling direction of the bubble 17 (hereinafter, the traveling direction of the bubble is assumed to be 18 for simplicity). It is characterized in that the angle 15 with the difficult axis 11 is smaller than the angle 16 between the other rising part and 11. That is, in conventional patterns including the above-mentioned roof top pattern, the angles ]5 and 16 are made equal, and a bubble transfer margin as shown in the figure is obtained. This bubble transfer experiment (support) has a film grown on a 30a5'l□ single crystal substrate with a thickness of about 1.2 μm, a stripe width of about 1.1 μm, a saturation erosion rate of about 650 Gauss, -'ill
Anisotropic magnetic field of approximately 1700 Oersted (Oe) (
A bubble film consisting of YSmLuUiCa)3(J("elJe)50
Accelerate e+ ions with energies 5QKeV and 140KeV
about 2B]5/crn2 and about 4. E] 5
/cyn2 was injected. For transfer, quasi-static measurements were carried out using a total of 21 bits of mini-chire data including a 10-bit suit size track. The pattern period P is 4
It is μm.

The bubble transfer margin for a conventional no-turn where angles 15 and 16 are both approximately 45 degrees is 22 degrees. On the other hand, the pattern of this example had a significant transfer improvement effect as shown in 21.

Example 2 In the case of the transfer pattern of FIG. 3 in which the angle 15 of the pattern of Example 1 is made smaller to about 20, the quasi-static no-pull transfer margin is slightly improved compared to 21. Note that when the angle 15 was further reduced to zero, the margin decreased slightly compared to 21 due to the error of stopping within the bubble or cusp.

Embodiment 3゜Instead of the Bakun figure 3 of Embodiment 2, the angle J6 is set to about 45
In the case of the transfer pattern shown in FIG. 4, where the transfer pattern was set to 100°C, although it was slightly worse than 21, it was seen that there was an improvement in transfer compared to the conventional pattern.

Example 44 In the example J, instead of the pattern shown in FIG. 1, the pattern period is doubled to 81Lm and the angle 15 is about 20. If the pattern shape shown in Fig. 5 has an angle 16 of approximately 55, a quasi-static bubble transfer margin as shown in Fig. 6 61 can be obtained using the conventional angle 15.
The quasi-static bubble transfer margin for the pattern where and 16 are equal is 62. Low I Tr (intra-cusp bubble vibration in III is reduced and high bias I) The apex in Figure 5 is made in a curved shape. Create in a straight line1. If
Although the margin has decreased by about 5 points, the margin width is still wide.

Example 5 When a bubble transfer experiment was conducted using the pattern shown in FIG. 5 on a sample different from the sample described in Example 1, a quasi-static transfer margin as shown in FIG. 7 was obtained.

The sample used in this example had the same coating material as in Example 1 and had a film thickness of approximately 0.
．． On top of the bubble retaining layer, which has the characteristics of 9 μm, stripe width of approximately 1.011 m, III sum if, approximately 620 Gauss, and Q value of approximately 3, there is also a film thickness of approximately 0.4 μm, and a saturation correction layer of 6
:30 Gauss Q value approx. 2.2 (D (Od Sm 'l
)nCa)3(FeGe), This is a double film sample in which a drive layer of 01□ material was grown. Figure 7 71 is 100
Transfer margin of KeV 3E151-1e"/c1n2 (D ion implantation condition (hereinafter simply referred to as 100Δ"/3E15).

72 indicates a transfer margin of 120AJe+/4E15, and the third indicates a transfer margin of 160.41e''/51Ij15.

The results shown in FIG. 7 show that the pattern of this example is effective for bubble transfer with a wide margin even if the structure and material properties of the single-layer film and double-layer film, that is, the CD film, are slightly different, and even if the ion implantation conditions are slightly changed. Show that something is true.

In addition to lTh+)f'-,)su, NS, N
It can be easily inferred that this is also effective in the case of ion implantation.

Example 6 [Example 5] In a 20/i-1υ4J615 sample, a quasi-static bubble transfer margin was obtained using the pattern shown in FIG. When gold is measured; JXD Figure 91
The result was obtained. In addition, in FIG. 8, when the pattern period is 4P, that is, 16 μm, a quasi-static bubble transfer margin of 92 in FIG. 9 is obtained.

,'V,j2.According to the present invention, it is possible to reduce the drawbacks of the conventional pattern in the pad track of the CI) device, improve the transfer characteristics, and have a great effect on the functioning of the C1) device. Note that the pattern is rounded by pattern formation, and the pattern shape of the present invention naturally includes this kind of rounded pattern shape.

[Brief explanation of the drawing]

Figures 1.3, 4, and 5.8 are diagrams showing transfer patterns in embodiments of the present invention, and Figures 2.6 and 7.9 are diagrams showing bubble conditions in embodiments 1, 4, and 5.6, respectively. FIG. 3 is a diagram showing static transfer margins. In lnl, 1] is the axis of magnetization &!1 in the plane perpendicular to the transfer path, J2 and ]3 is the other two magnetizations in the plane
14 f; 1 pattern required purple vertex, 15 is the rising part of the pattern element on the hand 14jl side of the 1p point with respect to the bubble traveling direction (!: Angle made with value conversion 11'1illl, ]6 is The angle formed by the rising part of the pattern element of the sen that pinches point m and (menka + 1 times ■ 1), 17 is the bubble,
】8 is the bubble advance direction, 2] is the bubble transfer margin of the 1r11 Example 1 pattern, 22 is the bubble transfer margin of the 4E01 cycle conventional pattern, 61ζ;
? lJ 4 pattern bubble transfer margin, 62ha 8
Bubble transfer margin of itm cycle conventional pattern, 7]
, 72.73 is 10 in each of the 11 actual cases 5.
0A charge 4/3E] 5.120/1-I (!/41121
5.1fiO/II+amount 15E] 5. 91 and 92 represent bubble transfer margins under the ion implantation conditions of 5.1fiO/II+amount 15E], and 91 and 92 represent bubble transfer margins for pattern periods of 12 μln and J6 μn, respectively, in the implemented uG. Figure 1 Figure 2 Hi (Oe) Figure 5 Figure 6 Figure 7 Figure Hl- (Oe) Figure 8 Li 9 Figure 0 50 700 Hi (O
e)

Claims (1)

[Claims] Bubble (in-plane bent PfI is provided on the 1st section retention layer to form a transfer pattern, 4c of the in-plane magnetization layer, (the bubble retention layer is swamped into a pattern by the back wall and transferred) Conte f gear・Teisuku Bubble (at Kenku Motoko ↓;
■ Of the two rising parts that are perpendicular to one shielding difficult axis in 1 and sandwich the apex of the pattern element of the transfer path on the side of the arsenized solid layer axis, this is before the apex in the traveling direction of the bubble magnetic domain. A bubble Ii 1 element, characterized in that an angle between one rising portion and the hard magnetization axis is smaller than an angle between the other rising portion and the hard magnetization axis.