JPS61190779A - Formation method for magnetic bubble transmission channel - Google Patents

Abstract

PURPOSE:To form a bubble transmission channel without a residual defect, by removing a soft magnetism thin film, after forming a non-magnetic pattern overlapping in part with a negative type transmission pattern on a magnetic bubble crystal. CONSTITUTION:A pattern 12 is formed employing the non-magnetic materials of resin, metals, etc. on a bubble crystal 10, and then a non-magnetic film 13 is formed employing polyamide resin, etc. Then, on a film 13 a negative type pattern for bubble transmission 14 by a photoresist is formed so that a part of the steepy difference in grade of a pattern 12 is overlapped. Then, making the pattern 14 as mask, the etching of the film 13 is performed, on it a non- magnetic film 15 is formed in the whole surface, and later, the etching of the film 13 is performed again, and it is removed together with a film 15 found on it. By this, a soft magnetism thin film pattern for transmission channel 16 is formed.

Description

[Detailed Description of the Invention] [Summary] A method for forming a bubble transfer path in a magnetic bubble memory element, which involves forming a non-magnetic film on a magnetic bubble crystal, and forming a negative-type film that partially overlaps the step. After forming the transfer pattern and removing the soft magnetic thin film from the bottom, the soft magnetic thin film on the negative pattern is removed, making it possible to form a bubble transfer path with no residual defects. The present invention relates to a method for forming a pull transfer path in a magnetic bubble memory element, and more specifically, to a method for forming a bubble transfer path that prevents residual defects in a soft magnetic thin film due to dust etc. that adheres during the manufacturing process. It is something.

Conventional magnetic bubble memory devices have been used in electronic computing devices for information processing, etc., but as the number of information covers increases, the storage capacity and density of memory elements are required to increase, and the transfer pattern of rounded bubbles has been improved. Miniaturization is progressing.

Along with this, pattern defects due to dust and the like that adhere during the manufacturing process of the trapeiko have become a problem, although this is not so much of a problem when the pattern is large. Pattern defects include chips and residues that occur during etching, and in particular, bubbles emerge from the remaining defects, affecting even minor loops that are not defects. Malfunctions due to these remaining defects become more problematic as the transfer pattern becomes smaller and the spacer becomes thinner.

[Conventional technology]

FIG. 5 is a diagram illustrating a conventional method of forming a bubble transfer path. In this method, first, as shown in FIG. 5A, a non-magnetic layer 2 such as 5IO2 is entirely formed on a bubble crystal 1, and a soft magnetic thin layer 3 such as Permalloy is formed thereon.

Next, apply photoresist 4 on top of it as shown in tlIJ5.
to form a pattern. Next, as shown in FIG. 5C, etching is performed using the photoresist 4 as a mask, and then the photoresist 4 is removed to obtain a soft magnetic thin film transfer pattern 5.

[Problem that the invention seeks to solve]

In this conventional method, if dust etc. 6 adheres during resist pattern formation or during the subsequent etching process, the soft magnetic thin film remains in that area without being etched.
-Remaining "defect 7".

The present invention was created in view of this problem, and aims to form a bubble transfer path with no remaining defects. The objective is to provide a method for forming such materials.

[Means for solving problems]

In order to solve the above problems, the present invention includes a step of forming a non-magnetic butter layer 2f having a steep step with a first non-magnetic material on a magnetic bubble crystal, and a process of forming a non-magnetic butter layer 2f with a steep step on a magnetic bubble crystal, and a step of forming a non-magnetic film 13i on the non-magnetic film 13i, a step of forming a negative pattern 4 as a bubble transfer pattern on the non-magnetic pattern 13i, which partially overlaps the steep step of the non-magnetic pattern 12; a step of etching the non-magnetic film 13 using a mask as shown in FIG. The method is characterized by comprising steps of forming a soft magnetic thin film pattern 16 for bubble transfer.

[Effect]

A non-magnetic pattern is formed using a first non-magnetic material on the magnetic bubble crystal, a negative transfer pattern is formed using a second non-magnetic material to partially overlap the steps, and a soft magnetic thin film is formed on top of the negative transfer pattern. After modeling, it is necessary to remove the soft magnetic thin film on the negative pattern.The dust that adhered during the above process will cause a defect in the transfer path, and will not be a defect and will have a negative impact on other good loops. It becomes possible to prevent this.

〔Example〕

Figure m1 is a diagram for explaining the method of forming a magnetic bubble transfer path according to the first embodiment of the present invention. In the figure, figures a to f are cross-sectional views for explaining the process, figures g and h are plan views, and figure a is a cross-sectional view taken along line a-a of figure g,
Figure 0 is a cross-sectional view taken along the c-c line of figure h, and figure f is a cross-sectional view of figure 1.
It is a sectional view taken along the -f line.

To explain with the drawings, first, as shown in figures a and g, a non-magnetic pattern 12 with a steep step is formed using a first non-magnetic material (for example, resin or metal) on a bubble crystal 10 via a spacer such as SlO□. form. Next, as shown in Figure b, a non-fusible layer 13'z is formed using a second non-magnetic material (for example, a polyamide resin). Next, as shown in Figures C and H, a bubble is formed using photoresist on the non-magnetic film 3. A negative butter 714 for transfer is formed so as to partially overlap the steep step of the non-magnetic pattern 12. Next, as shown in figure d, the non-magnetic film 13 is etched using the negative pattern 141 as a mask. This etching is selective etching so as not to etch the first non-magnetic material pattern 2.Next, as shown in figure e, a non-magnetic thin film J5t- such as permalloy is etched.
Form on the entire surface.

Finally, as shown in Figs.
5, to form a soft magnetic thin film pattern 16 for a transfer path.

FIG. 2 is a diagram illustrating a case where dust adheres during the above process. This figure shows the same steps as in FIG. 1, and the respective symbols are also the same. In this example, if the dust particles 17 are deposited in the steps shown in Figures C and H, the non-magnetic film 13' remains on the part of the dust that was previously attached in the process shown in Figures D, and this is softened in the steps shown in Figures F and 1. The defect in the magnetic thin film @16 indicates that a defect 18 occurs.

If this method is implemented in accordance with this embodiment, even if dust or the like adheres during the transfer path forming process, the chipping can be treated as a defect. FIG. 3 is a diagram for explaining the method. In the figure, figures a to f are cross-sectional views for explaining the process, figures g, h, and i are plan views, figure a is a cross-sectional view taken along line a-a of figure g, and figure b
The figure is a cross-sectional view taken along line b-b of figure h, and figure f is a cross-sectional view taken along line f-- of figure 1.
It is a sectional view taken along the f line. In addition, in this figure, the same parts as in FIG. 1 are designated with the same reference numerals.

This embodiment differs from the previous embodiment in that the nonmagnetic pattern 12 made of the first nonmagnetic material has a two-layer structure that can be selectively etched with respect to each other.

To explain this embodiment with reference to the drawings, first, as shown in Figs.
12 nonmagnetic patterns with a two-layer structure using t are formed, and then a nonmagnetic film 13i of polyimide or the like is formed on the entire surface.Next, as shown in figures b and h, all negative patterns 14 for bubble transfer are formed using photoresist. Use this as a mask
After etching and trapping the non-magnetic film 13 as shown in the figure, a soft magnetic thin layer [15] such as permalloy is formed on the entire surface as shown in figure d. Next, as shown in figure e, the non-magnetic film 1357 is etched again to remove it together with the soft magnetic thin film thereon, and then the second layer 12b of the non-magnetic pattern 12 is etched with ATi as shown in figure f, together with the soft magnetic thin film 15 thereon. Then, the soft magnetic thin film pattern 16 for the transfer path is formed.

According to this embodiment, is the defect caused by dust like the previous embodiment? The missing part can be a defect, and the non-magnetic pattern 12
This has the advantage that the soft magnetic thin film 15t that does not contribute to the transfer can be removed.

FIG. 4 is a diagram for explaining a method for forming a magnetic bubble transfer path according to a third embodiment of the present invention. In the figure, figures a to f are cross-sectional views for explaining the process, figures g and h are plan views, figure b is a cross-sectional view taken along line bb and @ of figure ig, and f
The figure is a sectional view taken along line ff in figure h. In addition, in this figure, the same parts as in FIG. 1 are designated with the same reference numerals.

This embodiment differs from the first embodiment in that a second non-magnetic material is used to form a two-layer structure in which the non-magnetic pattern 13'fr can be selectively etched with respect to each other. To explain this embodiment with reference to the figure, first, as shown in alg, a non-magnetic pattern 1 is placed on a bubble crystal lO through a space Ti1k of StO, etc.
2Q is formed, then a resin film 13a of polyimide or the like that can be etched by plasma is formed as a first layer of nonmagnetic film, and an At film 13b is formed as a second layer thereon. Next, as shown in figures b and g, a negative pattern 14t for bubble transfer is formed using photoresist, and using this as a mask, the two-layer At film 13bi of the non-magnetic film 13 is etched by ion milling as shown in figure 0. 7cAz left @1
3b'? As a mask, use the first layer of resin film 13 as shown in figure d.
a k 02 Plasma etching.

At this time, undercuts can be made to control gas pressure, output, etc. as shown in the Eri diagram. Then e
After forming a soft magnetic thin layer such as Permalloy on the entire surface as shown in the figure, etching the resin 13ai as shown in figures f and h, and removing it together with the At film 13b and the soft magnetic thin film 15 on top of it, is transferred. Thus, a soft magnetic thin film pattern 6 for road use is formed.

If this embodiment is implemented, defects due to dust can be treated as defects as in the Jth embodiment, and the transfer pattern 1
It has the advantage that the Gisep Gt of 6 can be made narrower.

〔Effect of the invention〕

As mentioned above, if the present invention is implemented, there will be no remaining 9 defects due to the etching residue of the soft magnetic thin film, and there will be no remaining 9 defects due to the etching residue of the soft magnetic thin film. Therefore, it is possible to prevent a bad loop from having an adverse effect on other good loops, which is extremely useful in practice.

[Brief explanation of drawings]

Fig. 1 is a diagram for explaining the first embodiment of the present invention, Fig. 2 is a diagram for explaining defect formation in the first embodiment, and Fig. 3 is a diagram for explaining the second embodiment of the present invention. FIG. 4 is a diagram illustrating a third embodiment of the present invention, and FIG. 5 is a diagram illustrating a conventional method of forming a bubble transfer path. 1 to 4, 10 is a bubble crystal, 11 is a spacer, ] 2 is a non-magnetic pattern, ] 3 is a non-magnetic film, 14 fl photo 1/cyst negative pattern, 15 is a soft magnetic thin film, 16 is a soft magnetic It is a thin film pattern.

Claims (1)

[Claims] 1. a) forming a non-magnetic pattern (12) having steep steps on a magnetic bubble crystal using a first non-magnetic material; b) forming a non-magnetic pattern (12) on the entire surface using a second non-magnetic material; c) Forming a magnetic film (13), c) forming a negative pattern of a bubble transfer pattern (
14) to partially overlap the steep step of the non-magnetic pattern (12); d) etching the non-magnetic film (13) using the negative pattern (14) as a mask; e) forming a soft magnetic thin film (15) on the entire surface, f) etching the non-magnetic film (13) again and removing it together with the soft magnetic thin film (15) above it to form a soft magnetic thin film pattern for bubble transfer. (16) A method for forming a magnetic bubble transfer path consisting of each step of forming. 2. The method for forming a magnetic bubble transfer path according to claim 1, wherein the nonmagnetic pattern (12) has a two-layer structure that can be selectively etched with respect to each other. 3. Claim 1, characterized in that the nonmagnetic film (13) has a two-layer structure that can be selectively etched with respect to each other.
A method for forming a magnetic bubble transfer path as described in .