JPS6376179A - Manufacture of magnetic bubble memory element - Google Patents

Abstract

PURPOSE:To improve a flattening degree by etching locally a first insulating layer formed at a garnet film for a bubble and a primarily flattening the recessed part formed with a width wider than a conductor pattern width by a resin, then forming a conductor pattern and further, executing secondary flattening with a resin. CONSTITUTION:The first insulating layer 12 formed at a garnet film 11 for a bubble is etched and a recessed part 12a of the width wider than the pattern width of a conductor pattern 14 formed later is formed. Thereafter, the primary flattening is executed by an organic high polymer resin 13 and next, the conductor pattern 14 is formed at the recessed part 12a of the first insulating layer 12. Further, the secondary flattening is executed for the conductor pattern 14 by an organic high polymer resin 15. Thus, the positioning of the recessed part 12a and the conductor pattern 14 comes to be easier and satisfactory flattening can be executed.

Description

[Detailed Description of the Invention] [Summary] A method for manufacturing a magnetic bubble memory element, which comprises locally etching a first insulating layer formed in a garnet film for bubbles to form a recessed portion having a width wider than the width of a conductor pattern. The degree of flattening can be improved by forming a conductor pattern in the recessed portion, performing primary planarization using resin, and then performing secondary planarization using resin.

[Industrial application field]

The present invention relates to a magnetic bubble memory element used in a storage device such as an electronic computing device, and more specifically, to a method of manufacturing a magnetic bubble memory element with improved planarization of a conductor pattern.

A magnetic bubble memory device is made by forming a magnetic garnet film by liquid phase epitaxial growth on a single-crystal nonmagnetic substrate made of gadolinium, gallium, or garnet, for example, and then forming a pattern such as a half disk using a soft magnetic thin film such as permalloy on top of the magnetic garnet film by liquid phase epitaxial growth. The bubbles generated by the bubble generator according to the information are guided to the transfer path, and the information is set as "1" if there is a bubble in the pattern and "0" if there is no bubble. It is designed to write jQ. As for the device configuration, in order to speed up the access time, a major-minor type is mainly adopted, in which the information storage section is formed into many loops and writing is performed, and reading is performed via major lines.

In this major-minor one-sided system, transfer gates, swap gates, etc. are used to transfer bubbles between the minor loop and the major line.

These gates are composed of a soft magnetic thin film pattern such as permalloy and a conductor pattern that intersects with the pattern.

In such gates, the soft magnetic thin film pattern is formed on the conductor pattern via an insulating layer, so there is a problem that the conductor pattern creates a step, which deteriorates the bubble transfer characteristics. Deko. For this reason, the following flattening method has been considered.

[Conventional technology]

In the conventional planarization method, as shown in FIG.
There is a method of using resin for the interlayer insulation film 4, a method of embedding the conductor pattern 3 in the insulating film 2 formed on the garnet film 1 as shown in FIG. As shown, a resist pattern 6 is formed on the conductor pattern 3, and a SiO insulating film 7 is formed on the entire surface by sputtering or vapor deposition.
There is also a lift-off method that removes the SiO film thereon.

[Problem that the invention seeks to solve]

In the above-mentioned conventional planarization method, planarization using a resin as shown in FIG. 2a has a correlation between planarization and resin film thickness. In the conductor embedding method shown in Figure 2, it is difficult to align the recess provided in the insulating layer 2 and the conductor pattern 3.If the width of the recess is widened to facilitate alignment, flattening by the resin 4 may be incomplete. The lift-off method shown in FIG. 2C has disadvantages such as difficulty in selecting the material and damage to the conductor pattern during lift-off, reducing its reliability.

The present invention was created in view of these points, and an object of the present invention is to provide a method for manufacturing a magnetic bubble memory element that is easy to manufacture, has a large planarization effect, and does not reduce the reliability of the conductor pattern.

[Means for solving problems]

Therefore, in the present invention, the bubble garnet film 11
A process of locally etching the first insulating layer 12 formed in the first insulating layer 12 to form a recess 12a having a width wider than the pattern width of the conductor pattern 14 to be formed later; The steps include a step of planarizing, a step of forming a conductor pattern 14 in the recess 12a of the first insulating layer 12, and a step of second planarizing the conductor pattern 14 with an organic polymer resin I5. It is characterized by comprising.

[For production]

The recess 12a formed in the first insulating layer 12 is
By making the pattern width wider than No. 4, the recess 12a
This makes positioning of the conductor pattern 14 easy, and good flattening can be achieved by performing flattening with resin twice before and after forming the conductor pattern.

〔Example〕

FIG. 1 is a detailed explanatory diagram of the present invention, and a
Nd is the process diagram.

In this embodiment, first, as shown in FIG.
ft) 12 is formed on the garnet film 11, and a region larger than the position where the conductor pattern is arranged in the first insulating layer 12 is etched to form a recess 12a. Next, as shown in FIG.
First flattening is performed using the following steps. The degree of flattening at this time is small. Next, as shown in FIG. 1C, a conductive pattern 14 is formed in the concave portion 12a that has been subjected to the first planarization, and then a second planarization is performed using an organic polymer resin 15.
Finally, a soft magnetic thin film pattern 16 is formed as shown in FIG. 1d.

According to this example, in order to form a recess in an area larger than the conductor pattern in the insulating layer and flatten it twice, primary and secondary, the conventional method of simply applying resin onto the conductor (the 2
It has the advantage that the flattening effect is greater than that of the conventional lift-off method (Fig. 2 b), and that the accuracy of recess formation and conductor pattern alignment, which the conductor embedding method has, can be reduced compared to the conventional method (Fig. 2 b). As shown in Figure 2C), it does not damage the conductor and has excellent reliability.

〔Effect of the invention〕

As described above, the present invention has the advantages that the alignment accuracy of the conductor does not need to be loose, has a large flattening effect, and has excellent reliability, and is extremely useful in practice. It is.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the present invention in detail, and FIG. 2 is a diagram for explaining the conventional planarization method. In FIG. 1, 10 is a substrate, 11 is a garnet film, 12 is a first insulating layer (SiO□), 12a is a recess, 13 and 15 are organic polymer resins, 14 is a conductive pattern, and 16 is a soft magnetic thin film pattern. be.

Claims (1)

[Claims] 1. The first insulating layer (12) formed on the bubble garnet film (11) is locally etched to have a width wider than the pattern width of the conductor pattern (14) to be formed later. A step of forming a recess (12a) in the first insulating layer (12), followed by a step of performing primary planarization using an organic polymer resin (13), and then forming a conductive pattern (14) in the recess (12a) of the first insulating layer (12). Further, the conductor pattern (14) is coated with an organic polymer resin (14).
5) A method for manufacturing a magnetic bubble memory element, comprising the steps of performing secondary planarization according to step 5).