JPS59152584A - Production of magnetic bubble memory - Google Patents

Abstract

PURPOSE:To make foundation plating unnecessary to simplify the process, by forming a negative pattern of a bump forming part on a conductor thin film with a photoresist and plating the bump forming part to for a bump. CONSTITUTION:A conductor thin film 22 and a TaMo-Au or a TaMo-Au-TaMo to be a bump foundation are formed on a crystal 20 for bubble through a spacer 21 consisting of an SiO2 by a sputtering or vapor-deposition method. A photoresist 23 is applied as shown in Fig. (b) to form a negative pattern in the part where the bump should be formed. The bump forming part is plated with Au as shown in Fig. (c) to form a bump 24. Hereafter, various processes are performed successively as shown in figures and finally, windows 31 are opened in an insulating layer and a protection layer in the bump part as shown in Fig. (k) to complete a device. Since the conductor thin film before lithography is used as a conductive layer as a foundation of plating though the conductive layer is normally required as the foundation of plating, the process is simplified, and the range of selection of conductor and bump materials is extended.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a magnetic bubble memory device used as a storage device for an electronic computer or a terminal thereof, and particularly to a method for manufacturing the memory element.

(2) Background of the technology Magnetic bubble memory used as memory for terminals, etc. of N2 child computing devices has many features such as non-volatility, high storage density, and low power consumption, and furthermore, it does not contain any mechanical elements. Because it is a solid-state device, it has extremely high reliability and is expected to have a promising future as a large-capacity memory.

This magnetic bubble memory is made by forming a large number of thin film fine patterns using permalloy on a single crystal thin film such as orthoferrite, which has uniaxial anisotropy and has an easy axis of magnetization only in the O-axis direction of the crystal, or magnetic garnet. Then, by applying a bias magnetic field perpendicular to the film surface, the cylindrical magnetic domain (called a bubble) that is generated is moved along the transfer path of the shivermalloy pattern by an external magnetic field, and the presence or absence of bubbles in this permalloy pattern is determined at 11'',' 01 and is used as a memory.

(3) Prior Art and Problems FIG. 1 is a diagram for explaining the structure of a conventional magnetic bubble memory. In the figure, 1 is a bubble crystal, 2 is a spacer, 3 is a conductor for driving gates, 4 is an insulating layer, 5 is permalloy, and 6 is a protective layer.

7 indicates a plating base, and 8 indicates a bump for external connection.

FIG. 2 is a diagram for explaining the method of manufacturing the magnetic bubble memory shown in FIG. 1, and the steps are shown at p and a-. To explain with reference to the figures, first, as shown in Figure A, a spacer 2 and a conductor layer 3I are formed on a bubble crystal 1. Next, as shown in Figure b, a photoresist is applied and patterned to leave a portion of the resist 9 that will become a conductive pattern. Next, as shown in Figure C, the conductor layer is etched to form a conductor pattern 3. Next, an insulating layer 4 is formed as shown in Figure d. Next, a permalloy pattern 5 is formed as shown in figure e. Next, a protective layer 6 is formed as shown in figure f. Next, windows 10 and 10' reaching the conductor pattern 3 and permalloy pattern 5 in the insulating layer 4 and the protective layer 6 as shown in figure g.
Open. Next, base plating 7 is applied to the entire surface as shown in Figure h. Next, as shown in FIG. 1, photoresist 11 is applied, and the portions that will become bumps are patterned. Next, plating is performed as shown in Figure J to form bumps 8. Next, the photoresist is removed as shown in the figure, and finally the plating base other than the bump 8 portion is removed by etching to obtain a bubble memory as shown in FIG.

As described above, in the conventional manufacturing method, the bumps 8 are formed by vapor deposition or plating after opening the protective layer 6. Therefore, since pulp is formed through the protective layer, a conductive plating base is required. This plating base must be a metal that does not diffuse into both the conductor pattern 3 and the permalloy pattern 5 at high temperatures, and must also have good adhesion to the protective layer 5i02, but there are restrictions on its selection. There was a drawback. There is also the disadvantage that the need for base plating complicates the process.

(4) Purpose of the Invention In view of the above-mentioned conventional drawbacks, an object of the present invention is to provide a method for manufacturing a magnetic bubble memory that simplifies the process by not requiring base plating when forming bumps for external connection. It is something.

(5) Structure and object of the invention According to the present invention, after forming a conductor thin film, a negative pattern of a bump forming area is formed using photoresist, and then plating is performed on the bump forming area to form a bump. This is achieved by providing a method for manufacturing a magnetic bubble memory characterized by including steps of subsequently creating a conductor pattern.

(6) Examples of the invention Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 3 is a diagram for explaining the method of manufacturing a magnetic bubble memory according to the present invention, and B- is a cross-sectional diagram for explaining the process. The method of the present invention will be explained using figures.

First, as shown in figure a, 8102 is placed on top of the bubble crystal 20.
TaMo-Au or TaMo-Au TlMo which becomes the conductor thin film 22 and the bump base via the spacer 21
is formed by sputtering and vapor deposition methods. Next, as shown in Figure b, a photoresist 23 is applied to form a negative pattern in the area where bumps are to be formed. Next, as shown in Figure C, the bump forming portion is subjected to All plating to form the bump 24. Next, the resist is removed as shown in Figure d, and a photoresist 25 is applied as shown in Figure E, patterned by a projection exposure method, and etched to form a conductor pattern 26 as shown in Figure F. Then, as shown in figure g, resin coating or 5iOz
An insulating layer 27 is formed by sputtering. Next, as shown in Fig. h, a window for permalloy connection is formed in the insulating layer 27 by plasma etching to form a contact hole 28. Next, as shown in FIG. 1, permalloy is deposited and a permalloy pattern 29 is created by photolithography. Next, as shown in Figure J, a protective layer 30 of Si02 is formed, and finally, a window 31 is formed in the insulating layer and protective layer at the bump portion as shown in the figure to complete the process.

Note that when AA is used as the conductor, T+ (
After depositing a sufficient thickness, a negative pattern for bumps is created, and the bumps are formed by plating with Pt or Pd and Au. It can be created by depositing Or (thickness 500λ) on Afl and then plating O and Au. Further, the combination of materials for the conductor and bumps is not limited to the above, and various configurations are possible.

(7) As described in detail, the method for manufacturing a magnetic bubble memory of the present invention simplifies the process by using a conductive thin film before phosphorography instead of a conductive layer that normally requires a conductive layer as a base for plating. It has become possible.

Furthermore, since it is no longer necessary to select a plating base suitable for both the conductor and permalloy, the range of selection of conductor and lamp materials is significantly expanded, and the effect is remarkable.

[Brief explanation of drawings]

Figure 1 is a diagram for explaining the configuration of a conventional magnetic bubble memory, Figure 2 is a diagram for explaining a method for manufacturing a conventional magnetic bubble memory, and Figure 3 is a diagram for explaining a method for manufacturing a magnetic bubble memory according to the present invention. FIG. In the drawing, 20 is a bubble crystal, 21 is a spacer,
22 is a conductor thin film, 23 and 25 are photoresists, 24 is a bump, and 26 is a conductor pattern. 27 is an insulating layer, 28 is a contact hole, 29 is a permalloy pattern, 30 is a protective layer, and 31 is a window. Figure 1

Claims (1)

[Claims] 1. After forming the conductor thin film, form a negative pattern of the bump forming area with photoresist, then plate the bump forming area to form the bump, and then conductor=
A method for creating a magnetic bubble memory characterized by including steps of creating a pattern.