JPS60251588A - Formation of magnetic bubble memory element - Google Patents

Abstract

PURPOSE:To improve the manufacture yield of the magnetic bubble memory element of dual spacer constitution by forming a specific spacer layer and a ''Permalloy(R)'' layer continuously by the same vacuum film forming device. CONSTITUTION:The 3rd spacer layer 14 and ''Permalloy(R)'' layer 15 are formed continuously on a crystal 10 for magnetic bubbles by using the same vacuum film forming device, and a pinhole 19 due to dust 18 on the crystal 10 is formed in the lamination part of the layers 14 and 15. Therefore, a ''Permalloy(R)'' pattern 17 after patterning does not contact the crystal 10 and trouble due to new creation is prevented, thereby improving the manufacture yield of the magnetic bubble memory element of dual spacer constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for making a magnetic bubble memory element used in a storage device such as an electronic computing device.

Background of the Technology As semiconductor technology advances, magnetic bubble memory devices are constantly required to have higher storage densities.

For this reason, permalloy patterns, which are memory elements, are becoming increasingly finer. However, although it has become possible to miniaturize the permalloy pattern in the information storage part (minor loop) by modifying its shape, the functional parts of gates are constructed by combining a conductor pattern and a permalloy pattern. Therefore, miniaturizing the permalloy pattern makes it difficult to align it with the conductor pattern during its creation. Therefore, a method has been developed in which the information storage portion is formed using a fine pattern, and the other portions are formed using large patterns. In this case, in order to ensure that there is not much difference in driving force between the two patterns due to the same rotational driving magnetic field, the distance from the surface of the crystal 1 to the permalloy pattern is made smaller for the fine pattern 2 and larger for the larger pattern 3Fi, as shown in Figure 1. A so-called dual spacer method is used in which the spacer thickness is adjusted accordingly. In the figure, 4 is a first spacer, 5 is a conductor pattern, 6 is a second spacer, and 7 is a third spacer.

Prior Art and Problems Conventionally, this dual spacer structure has been fabricated by a process as shown in FIGS. 2a-d. In FIG. 2, the same parts as in FIG. 1 are designated by the same reference numerals.

Also, figure a is before the creation of the third spacer, figure b is the creation of the third spacer layer, figure C is wafer surface cleaning, figure d is permalloy vapor deposition,
Each shows pattern creation.

In such a production process, if there is dust 8 such as particles on the base (first and second spacer removed portions) before forming the third spacer layer as shown in figure a, the third spacer layer 7 will not be formed as shown in figure b. After coating, the above-mentioned dust is removed by cleaning the wafer surface (washing with detergent, etc.) as shown in Figure C, and the pinhole 9 is removed.
becomes. After that, when permalloy is vapor-deposited to form a pattern 2.3 as shown in Figure d, the permalloy 2 comes into direct contact with the crystal 1 at this pinhole portion 9, and a nucleation error occurs from this point, resulting in a defective chip. Furthermore, even if cleaning the wafer surface is omitted, the third spacer layer is formed using a sputtering device, and the permalloy film is formed using an electron beam evaporation device, so after the third spacer layer is formed, the electron beam There was a problem in that dust and the like adhered again during the transfer to the vapor deposition apparatus, further deteriorating the yield.

OBJECTS OF THE INVENTION In view of the above-mentioned conventional problems, it is an object of the present invention to provide a method for manufacturing a magnetic bubble memory element that makes it possible to improve the yield of magnetic bubble memory elements having a dual spacer configuration.

According to the present invention, a first spacer layer having at least one layer, a conductor pattern, and a second spacer layer having at least one layer are provided on a crystal for a magnetic bubble, and In the method for manufacturing a magnetic bubble memory element having a dual spacer structure, the first spacer layer and the second spacer layer are partially removed, a third spacer layer is formed after that, and a permalloy pattern is formed on the third spacer layer. This is achieved by providing a method for producing a magnetic bubble memory element, which is characterized in that three spacer layers and a Vermalloy layer are successively produced in the same vacuum film forming apparatus without breaking the vacuum.

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 a method for manufacturing a magnetic bubble memory element according to the present invention, and a to d are diagrams for explaining the process. In the figure, 10 is a crystal for magnetic bubbles, 11
12 is a conductor pattern, 13 is a second spacer layer using PLO8 resin, 14 is a third spacer layer using 5i01, etc., 15 is a first spacer layer using StO, etc.
is a permalloy layer, 16 is a large permalloy pattern, 1
7 indicates a fine permalloy pattern, 18 indicates dust, and 19 indicates a pinhole.

In this embodiment, as shown in Fig. a, a first spacer layer 11 made of StO or the like is first formed on a magnetic bubble crystal 10, a conductor pattern 12 is formed on it, and a second spacer layer 11 is formed on it.
After applying the POLS resin as the spacer layer 13, the first and second spacer layers are removed in the region where the micro permalloy pattern is to be formed.

Next, as shown in figure b, the third spacer layer (
Vapor deposition of SiO or Sin) 14 and permalloy layer 15 are successively formed. Next, after cleaning the wafer surface as shown in Fig. C, the permalloy layer 15 is patterned by photolithography to form a large permalloy pattern 16 and a fine permalloy pattern 17 as shown in Fig. d.

In this embodiment, which is carried out in this way, even if there is dust 18 on the crystal 10 before the formation of the third spacer layer as shown in Figure A, this dust is removed from the permalloy layer as shown in Figures B and C. Make a pinhole 19 at the size of 15. Therefore, as shown in Figure d, the permalloy pattern 17 after patterning is not in contact with the crystal 10. Therefore, defects due to nucleation do not occur and the yield of chips improves.

Note that in this embodiment, the eleventh second spacer layer 11.
Although No. 13 has been shown to have an increased number of layers, it goes without saying that the method of the present invention can also be applied to structures having two or more layers.

Effects of the Invention As explained in detail above, the method for producing a magnetic bubble memory element of the present invention involves sequentially forming the third spacer layer and the permalloy layer in the same vacuum film forming apparatus in the dual spacer configuration. In particular, this has a great effect in preventing defects caused by dirt and the like, and making it possible to improve the yield of chips.

[Brief explanation of the drawing]

Fig. 1 is a diagram for explaining the dual spacer configuration of a conventional magnetic bubble memory element, Fig. 2 is a diagram for explaining its manufacturing process, and Fig. 3 is a diagram for explaining the manufacturing method of a magnetic bubble memory element according to the present invention. It is a figure for explaining. In the drawing, 10 is a crystal for magnetic bubbles, 1 is a first spacer layer, 12 is a conductor pattern, 13 is a second spacer layer, 14 is a third spacer layer, 15 is a permalloy [,
16 indicates a large permalloy pattern, and 17 indicates a fine permalloy pattern.

Claims (1)

[Claims] 1. Having a first spacer layer having at least one layer, a conductor pattern, and a second spacer layer having at least one layer on the magnetic bubble crystal, and removing part of the first spacer and second spacer layer in the chip. In a method for manufacturing a magnetic bubble memory element having a dual spacer layer structure, in which a third spacer layer is then created and a permalloy pattern is created on top of the third spacer layer, the third spacer layer and the permalloy layer are formed in the same vacuum film forming apparatus. A method for producing a magnetic bubble memory element characterized by continuous production without breaking the vacuum within the device.