JPH0646500B2 - Magnetic bubble transfer path - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic bubble transfer path, and more particularly to a magnetic bubble transfer path formed from an asymmetric Sieplon pattern, a half disk pattern or a similar pattern. is there.

BACKGROUND OF THE INVENTION Generally, as a magnetic bubble transfer path, a so-called field access method in which a soft ferromagnetic thin film pattern such as permalloy is magnetized by a rotating magnetic field is mainly used. As the pattern of this magnetic bubble transfer path, a pattern of the kind shown in the enlarged plan view of the main part in FIG. 1 has been mainly used so far. That is, (a) of the figure shows a transfer path formed by using the asymmetric shippron pattern 10 as a basic pattern, (b) shows a transfer path formed by using the half disk pattern 11 as a basic pattern, and (c) of FIG. 3A and 3B respectively show transfer paths configured by using the character pattern 12 as a basic pattern. These transfer patterns are, for example, IEEE Transactions on
Magnetics, VoL.MAG-12, No.6, November 1976.P614-P617
And P651-P653.

However, due to the higher integration and higher density of magnetic bubble memory devices in recent years, the diameter of the magnetic bubble used is about 1.5.
It has been miniaturized from μm to about 1.0 μm.
Similarly, for the magnetic bubble transfer path, if the period of the basic pattern is λ, as shown in FIG.
Recently, the size of the basic pattern is reduced to about 8 μm, whereas the basic pattern is the gap g between patterns and the pattern width W, which is the limit of the photolithography technique.
Patterns up to about 1.0 μm are used,
In the future, these patterns tend to be further miniaturized.

When the pattern is miniaturized in this manner, there has been a problem that the actual finished pattern is largely deformed by a slight change in the pattern manufacturing process. FIG. 2 shows a conventional example of this pattern modification. In the figure, the deformed pattern 10b as shown by the dotted line is completed with respect to the normal pattern 10a shown by the solid line. As a result, the substantial gear gap indicated by the minimum inter-pattern gear gap g'between the basic patterns 10 is greatly expanded, and when the miniaturized magnetic bubbles are transferred to the transfer path formed by this modified pattern, 3 rotating magnetic field as shown in FIG. (H _R) -
The upper limit value I _{U of the} bias magnetic field (H _B ) characteristic is the rotating magnetic field H _R
Becomes as low as about 50e, it deteriorates extremely to I _U ′,
There has been a problem that the stable operation area A surrounded by the upper limit value I _U and the lower limit value I _D becomes narrow.

[Object of the Invention]

Therefore, the present invention has been made to solve the above-mentioned conventional problems, and the purpose thereof is to:
A rotating magnetic field-bias magnetic field characteristic with a wide stable operation area can be easily obtained even if the basic pattern and the magnetic bubble forming the magnetic bubble transfer path are miniaturized, and the pattern is stable and does not deform even when the manufacturing process is changed. It is to provide a difficult magnetic bubble transfer path.

[Outline of Invention]

According to the present invention, in order to prevent the problem that the tip of the foot portion of the transfer pattern is rounded by the photographic process, and thereby the gap between the output portion and the input portion of the adjacent transfer pattern is widened, the foot tip portion is provided with a protrusion. According to the present invention, the following magnetic bubble transfer path is provided.

In a magnetic bubble transfer path formed by arranging a magnetic bubble transfer pattern having an inlet side foot portion into which a magnetic bubble is transferred in and an outlet side foot portion from which it is transferred out along the magnetic bubble transfer direction,
A magnetic bubble transfer path integrally formed at the tip of the foot portion with a pattern protrusion made of the same member as the transfer pattern and having a width narrower than the width of the foot portion measured in the transfer direction.

Example of Invention

 Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 4 is an enlarged plan view of an essential part for explaining one embodiment of the magnetic bubble transfer path according to the present invention. In the figure, the inlet side foot of the magnetic bubble is 10 _I and the outlet side foot is 10 _O with respect to the magnetic bubble transfer direction P of the asymmetric chevron pattern 10 ′.
At this time, the projecting portions 10 _C projecting stepwise in the direction intersecting the magnetic bubble transfer direction P are integrally provided at the tip portions of these foot portions 10 _I and 10 _O.

In addition, the foot portion 10 of such an asymmetrical Siebrow pattern 10 '
_{In order} to provide the protrusion 10c at the tip of _I , 10 _O , a fifth mask is used to transfer the asymmetrical Sieblo pattern 10 '.
The chrome mask pattern 100 formed on the glass substrate by the electron beam drawing method as shown in the figure has a shape substantially the same as that of the stepped protrusion 10 _C in the portion corresponding to the tips of the legs 10 _I and 10 _O. This can be easily achieved by using the photomask 100c of 1) formed by electron beam drawing.

In this way, by providing the protrusions 10 _C projecting in the direction intersecting the magnetic bubble transfer direction at the tips of the feet 10 _I and 10 _O of the asymmetrical siebelo-pattern 10 ′, it is possible to reduce the manufacturing process of the asymmetrical sieblon pattern 10 ′. Even if there is a change in
The pattern deformation generated at the tips of 10 _I and 10 _O becomes the shape of the deformation pattern 10b 'as shown by the dotted line in FIG. 6, and there is no substantial variation in the minimum pattern gap g between the sieblon patterns 10'. You can secure enough. Therefore, the miniaturized magnetic bubbles flow from the exit side foot portions 10 _{O of} the asymmetric chevron patterns 10 ′ adjacent to each other to the entrance side foot portions 10 _{I of} the asymmetric chevron pattern 10 ′ adjacent to the magnetic bubble transfer direction P. Easily transferred to a rotating magnetic field H _R of about 50
Even if it is reduced to about e, the upper limit value I _U is shown in FIG. 3, and the stable operation region can be expanded.

7 (a) to 7 (f) are enlarged cross-sectional views of the essential parts showing another embodiment of the magnetic bubble transfer path according to the present invention. In FIG. 3A, a bar-shaped protruding portion 10d having a pattern length of about 1/3 to 1 times the magnetic bubble diameter is provided only at the tip of the magnetic bubble outlet side foot portion 10 _O of the asymmetric Siebrow pattern 10 ′. Are provided in a direction orthogonal to the magnetic bubble transfer direction. In the same figure (b), a bar-shaped protrusion 10 _O is similarly provided only on the tip of the magnetic bubble inlet side foot 10 _I , and in the same figure (c) the magnetic bubble inlet side foot 10 I is provided.
_I and the outlet-side leg portion 10 _O both the projecting portion 10d of, 10e to those provided respectively. Further, FIG. 7D shows a magnetic bubble outlet side foot 10 _O provided with a protrusion 10 f having a bent portion in the magnetic bubble transfer direction P, and FIG.
To _I, the protruding portion 10g having a bent portion to the magnetic bubble transfer direction P opposite direction is provided, and FIG. (F) a magnetic bubble inlet side leg portion 10 _I
The bar-shaped protrusion 10e shown in FIG.
_The protrusions 10f shown in FIG.

By providing various protrusions on the magnetic bubble inlet / outlet side foot of the asymmetrical chevron pattern 10 'in this way, the gear gap g between the chevron patterns 10' is substantially at a predetermined value against variations in the manufacturing process. since can be secured to, and improved magnetic bubble transfer characteristic, the rotating magnetic field as described in FIG. 3 (H _R) - a bias magnetic field (H _B) characteristics can be greatly improved.

In the above-described embodiment, the magnetic bubble transfer path pattern has been described as the basic pattern of the asymmetrical chevron pattern, but the present invention is not limited to this, and the half disk described in FIG. Even if the present invention is applied to a pattern, a C-shaped pattern or a similar parallel gear pattern, the same effect as described above can be obtained.

〔The invention's effect〕

As described above, according to the present invention, it is possible to improve the magnetic bubble transfer characteristics in the gap portion between the basic patterns, so that it is possible to realize a high-density magnetic bubble memory device with high quality and reliability. The extremely excellent effect of is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and FIG. 2 are enlarged plan views of main parts for explaining an example of a conventional magnetic bubble transfer path, and FIG. 3 is a rotating magnetic field of the magnetic bubble transfer path according to the related art and the present invention. (H _R) - shows the bias magnetic field (H _B) characteristics, Figure 4 is a fragmentary enlarged plan view showing an embodiment of a magnetic bubble transfer path according to the present invention, magnetic bubble transfer path according to Fig. 5 the invention FIG. 6 is an enlarged plan view of an essential part showing an example of a chrome mask pattern used when manufacturing the magnetic disk, FIG. 6 is a view for explaining a state in which the magnetic bubble transfer path according to the present invention undergoes pattern deformation due to manufacturing variations. 7 (a) to 7 (f) are enlarged plan views of essential parts for explaining another embodiment of the magnetic bubble transfer path according to the present invention. 10 ′ …… Asymmetrical chevron pattern, 10 _I …… magnetic bubble inlet side foot, 10 _O …… magnetic bubble outlet side foot, 10c, 10
d, 10e, 10f …… Projection, 100 …… Chrome mask pattern, 100c …… Photo mask.

Claims (1)

[Claims] 1. A magnetic bubble transfer path having a magnetic bubble transfer pattern having an inlet side foot portion into which a magnetic bubble is transferred and an outlet side foot portion from which the magnetic bubble is transferred is arranged along a magnetic bubble transfer direction. A magnetic bubble transfer path, wherein a pattern projecting portion, which is made of the same member as the transfer pattern and has a width narrower than a width of the foot portion measured in the transfer direction, is integrally provided at a tip portion.