JPS61123083A - Magnetic bubble memory element - Google Patents

Abstract

PURPOSE:To eliminate the illegibility of marker pattern and to make positioning with high accuracy and to obtain high density bubble memory element by forming marker pattern on thin magnetic film in upheaval shape which is used for the positioning of each pattern. CONSTITUTION:A transfer pattern forming mask 3 on thin magnetic film 2, conductor pattern positioning maker pattern 4, and 'Permalloy(R)' pattern positioning marker pattern are simultaneously formed and ion-implanted. And, the mask 3 is crossed out by etching, and marker patterns 4, 5 are left in upheaval shape. Then insulating layer 7 is coated on it, and conductor pattern 8 and a marker pattern 9 are formed with the marker pattern 4 as a reference. Since there are marker patterns 4, 5, the upheaval pattern is quite clear even though the insulating layer 7 is coated on it, resulting in easy positioning. Then planarize by insulating resin layer 10, and form 'Permalloy(R)' pattern 11 and marker pattern 12 using the marker pattern as a reference point, and then insulating layer is formed on it.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention provides a Noive'J node type magnetic bubble in which a bubble transfer pattern formed by ion implantation and a bubble transfer pattern formed by a magnetic material pattern such as permalloy are mixed in one chip. It relates to memory elements, and in particular to the configuration of alignment markers used during pattern creation in the element creation process. Bubble memory, which is a non-volatile memory, does not require a movable mechanism and can be mounted on a printed board, making it extremely reliable. They have superior characteristics over magnetic disks, floppy disks, etc., such as high performance, long lifespan, and relatively fast information read/write access.

Incidentally, like other memory media, the storage capacity If1' of magnetic bubble memory continues to increase from IMbit to 4Mbit, and along with this, patterns are getting smaller and finer. In order to form the pattern with precision, the accuracy between the patterns (O1
1. The alignment technique is important.

[Conventional technology]

FIG. 5 shows a cross-sectional view of a conventional manufacturing process of a hybrid bubble device.

In the figure, 1' is a GGG (gadolinium gallium garnet) substrate in wafer state, 2' is a magnetic thin film, and 3
' is a mask for forming an ion implantation transfer pattern (providing a large number of minor transfer paths for bubble storage), 4' is a pattern for forming alignment markers of body pattern 8', 6
a' is an ion implantation part, 6b' is an ion implantation transfer pattern, 6C' is a marker pattern for mask positioning of conductor pattern 8', 7/10'.

13' is an insulating layer, 8' is a conductor pattern for bubble control,
9' is a marker pattern for alignment of the Habermalloy pattern 11', 11' is a permalloy pattern forming a bubble transfer path such as a hamstring line, and 12' is a marker pattern for permalloy.

As shown in step (a), a magnetic thin film 2' of magnetic garnet or the like is formed on the GGG substrate 1' by the liquid phase growth method, and a pattern 4' and a mask 3' for forming a transfer pattern are simultaneously formed on its surface. do. At this time, a plurality of groups of masks 3' are formed on the wafer surface of the magnetic thin film 2' so that a plurality of chips are formed, but a predetermined number of patterns 4' are formed in areas not used as chips, that is, in the four corners of the wafer. Ru.

The pattern material of 3' and 4' is, for example, Cr-Au. From this state, ions such as Ne or hydrogen are implanted multiple times as necessary onto the entire surface of the magnetic thin film 2'.

Next, as shown in (b), when the mask 3' and the pattern 4' are removed by etching, a continuous disk-shaped ion implantation transfer pattern 6b' and a marker pattern forming a minor transfer path surrounded by the ion implantation part 6a' are formed. 60
' appears. At this time, the ion-implanted portion 6a' swells to about several tens of heights, and a slight step is formed. Thereafter, as shown in (c), the conductor pattern 8' and the marker pattern 9' are used as alignment markers between the conductive patterns 8' and the marker patterns 6c''k patterns, and the patterns are simultaneously At this time, the step portion of the ion implantation part 6a' covered with the insulating layer 7' becomes smaller, and the position of the marker pattern 6c' becomes unclear, so that the transfer pattern 6b' and the conductor pattern 8
The positioning accuracy of ' is poor and is +0.3 μm in the worst case. Thereafter, as shown in (d), an insulating layer 10' made of PLO8 (poly-ladder organo-siloxane) resin or the like is formed.
Perform the flattening process and add permalloy butter/Il' to -L. : Marker pattern 9' is used as a positioning marker between the patterns on Bermalloy marker pattern 12' and patterns are formed at the same time, and an insulating layer 13' for protection is formed to produce a wafer-shaped bubble memory element. do. Thereafter, a large number of bubble memory devices are obtained by dividing the wafer.

By the way, in the step d>, the alignment accuracy of permalloy pattern 11' and transfer pattern 6b' is 11% for bubble memo.
Although this is an important process as it greatly affects the characteristics of the quintuplets, it is extremely difficult to see the step position of the transfer pattern 6b' due to the insulation 1m 7', 10', etc.

For this reason, conventionally, the positions of the transfer pattern 6b' and the permalloy pattern 11' are indirectly aligned by performing alignment using the conductor marker pattern 9' and the permalloy marker pattern 12'. In this case, since the marker pattern 9' includes a large formation error, it is impossible to align the patterns with each other with high precision.

[Problems to be Solved by the Invention] Conventionally, the alignment markers are also etched when etching the transfer pattern forming mask after ion implantation, making the alignment marker portions of the ion implantation transfer patterns very difficult to see. Moreover, since the marker portion is coated with an insulating layer, the alignment with the conductive pattern forming mask becomes even more unclear, and it becomes almost invisible during the permalloy pattern forming process. For this reason, in the past, the alignment of the ion implantation transfer pattern and the Vermalloy pattern had to be done indirectly using a conductor marker pattern, and it was not possible to form a pattern with a high degree of 111 degrees, resulting in a high reliability σ) high-density bubble memory element. I couldn't get it.

The purpose of the present invention is to solve the problems mentioned above. [Means for solving the problems] As a means to solve the problems mentioned above, in the present invention, ions are introduced into a magnetic thin film by ion implantation. In a magnetic bubble memory element in which an injection transfer pattern is formed, and a conductor pattern and a magnetic material pattern are formed on the magnetic thin film by covering an insulating layer, the ion injection transfer pattern or the magnetic material pattern is formed on the magnetic thin film. A magnetic bubble memory element is provided in which at least one of the magnetic material patterns has a marker pattern for mask positioning formed in a raised shape.

[Effect]

In this method, marker patterns for alignment between patterns are formed in a raised shape on the magnetic thin film, which often causes problems such as difficulty in seeing the marker patterns, making it difficult to perform high-precision alignment between patterns. can.

〔Example〕

The present invention will be explained using the production of a hybrid bubble memory element as an example.

FIGS. 1(a) to (d) are cross-sectional views showing the manufacturing process of the Vibe'I nodobubble memory device according to the first embodiment of the present invention, and FIG. 3 is a cross-sectional view showing the manufacturing process of a high print bubble memory device according to an embodiment, FIG.
FIG. 12A is a plan view showing a junction between the minor transfer path and the major transfer path in the figure, and FIG.

In these figures, 1 is a GGG (gadolinium gallium φ garnet) substrate, 21-j: magnetic thin film, 3°14
is a mask for forming an ion implantation transfer pattern, 4 is a marker pattern for a conductor pattern, 5 is a marker pattern for a permalloy pattern, 6 and 18 are ion implantation parts, ? , In, 13 is an insulating layer, 8 is a conductor pattern, 9 is a marker pattern of a conductor pattern, 11 is a permalloy pattern, 12 is a marker pattern of a permalloy pattern, 15. ! =16H pattern alignment marker pattern forming mask, 15' is a marker pattern for permalloy patterns, 16' is a marker pattern for conductor patterns, 17 is resist, 19 is an ion implantation transfer pattern, 2° is a marker section, 20' is a groove formed by etching, 21 is a bubble generator, 22 is a write measure line, 22' is a read measure line, 2
3 is a write gate that performs a transfer function and a swap function, 24 is a minor loop, 25 is a read gate that performs a block replication function, 26 is a detector, 27,
28 and 29 are permalloy patterns.

First, the overall structure of the magnetic bubble memory element according to the present invention will be explained with reference to FIGS. 3 and 4.

This magnetic bubble memory element has a magnetic thin film 2, a bubble generator 21, major lines 22, 22', write gate 23, minor loop 24, read gate 25,
The detector 26 is configured by forming a pattern and forming a product f4 17. In this magnetic bubble memory device, bubble information generated by the bubble generator 21 is transferred to the major line 22 and written into the minor loop 24 by the write gate 23. Information in the minor loop 24 is read out to the major line 22' by the bladder outlet gate 25 and detected by the detector 26.

At the junction of the major line and minor loop in FIG. 3, as shown in FIG. 4 (a) (t+), a minor loop 24 consisting of an ion implantation transfer pattern in the non-ion implanted region is formed in the magnetic thin film 2 by ion implantation. A U-shaped conductor pattern 8 is formed by covering an insulating layer 7 thereon, and a permalloy pattern 27 constituting a major line 22 (22') by further covering an insulating layer 10 thereon.
, 28 and 29 are formed, and the picanox vermalloy pattern 27 faces the cusp of the minor loop 24, and the conductor pattern 8 is arranged on a line connecting both.

At the junction, a current pulse applied to the conductor pattern 8 causes a bubble to move from the minor loop 24 to the major line 22 (22') or from the major line 22 (22').
) to the minor loop 24, it is particularly necessary to accurately form the positional relationship between the minor loop 24 and the permalloy pattern 27.

Next, FIG. 1 and FIG. 2 show examples f of the characteristic parts of the present invention.
explain.

FIGS. 1(a) to (1) show hybrids according to a first embodiment of the present invention in which the pattern 00'r positional relationship can be formed with high accuracy.

FIG. 3 is a cross-sectional view showing a manufacturing process of a dopple memory element.

- First, as shown in (a), magnetic m-pupil 2.1- All and Cr-
When forming the Au transfer pattern shape Tly mask 3, the conductor butter/marker pattern 4 is
+ UV VC perm IU pattern alignment marker pattern 5 is simultaneously formed and ion implantation is performed. After that, etching (mask 3 for forming the transfer pattern)
Remove only the marker pattern 1-7, remove the marker pattern 4 and 5 with a cold cloth 1. By keeping it in place, the uncut residue is formed into a raised shape without etching.

Marker patterns 4 and 5 elements with this #J extension! +! f('IVc) is formed on the four corners of the wafer which has a large influence.Furthermore, as shown in (c), the insulator 1?iJ7 is coated and the conductor pattern 8 and driver pattern 9 are positioned in the marker pattern 4f pattern ( The alignment is done using marker pattern 4,
5 exists, so even if the insulating layer 7 is covered, the protrusion vi
f! For 1 yen light, it will be aligned and fine.

Then, as shown in (d), a resin insulating layer] is formed with OK and brainerization, and then a permalloy pattern 11 and a marker pattern 12 are formed using the marker butter 75f pattern for positioning.Finally, an insulating layer 13 is formed. As a result, a bubble memory element according to the present invention is manufactured.

FIG. 2 is a diagram showing an embodiment of a song according to the present invention.

In the iH example, the second dog does not separate, but forms a transfer pattern forming mask 14 and alignment marker pattern forming masks 15 and 16 as shown in FIG. 2(a), and then implants ions into the entire surface. Then, the ion implantation section 18 is formed. Next, as shown in (b), mark resist 17 with marker 'Fil (20k
It is applied to the transfer pattern forming mask 14 and its surroundings (memory use area) except for the transfer pattern formation mask 14. Next, taking full advantage of the fact that the ion implanted portion 18 has a higher etching speed than the non-ion implanted portion, the ion implanted portion 18 of the marker portion 20 is etched to completely remove a portion of the bubble crystal to form a groove 20'. Thereafter, as shown in (c), by removing the resist 17 and the transfer pattern formation masks 14 and 15, 16k, the ion implantation transfer pattern 19 is formed, and at the same time, the ion implantation transfer pattern 19 is formed. Alignment marker patterns 15' and 16' are formed.

The state Fi of FIG. 2(c) according to this embodiment FIG. 1(b)
After that, conductor and permalloy patterns are formed in the same manner as in FIGS. 1(c) and 1(d).

In this example, Fig. 1 (Kojoji before forming the CL insulation layer
This is particularly effective when there is a risk that the marker mask 14, 15 may peel off at some point.

〔Effect of the invention〕

According to the magnetic bubble memory device of the present invention, since the marker pattern for alignment between patterns is formed in a raised shape on the magnetic thin film, the marker pattern is not difficult to see, so the accuracy of alignment between patterns is improved. , a high-density bubble memory device with good device characteristics can be manufactured with good reproducibility, and its practical effects are great.

[Brief explanation of drawings]

FIGS. 1(a) to 1(d) are cross-sectional views of a first embodiment of the method for manufacturing a magnetic bubble memory device according to the present invention, and FIGS.
The figure is a cross-sectional view for explaining another embodiment of the method for manufacturing a magnetic bubble memory device according to the present invention. FIG. 3 is a block diagram of a bubble transfer path of a hybrid bubble memory device manufactured according to the present invention, and FIG.
FIG. 4 is an enlarged plan view and cross-sectional view of the joint between the minor loop and the permalloy pattern in FIG. 3; FIGS. 5(a) to 5(d) are diagrams for explaining a method of manufacturing a conventional magnetic bubble memory element. [Symbol t Yueming] 3.14 Mask for forming ion implantation transfer pattern, 4, 16' Marker pattern for alignment between patterns for conductor pattern, 5, 15' Position between patterns for permalloy pattern Marker pattern for alignment, 6.18 Ion implantation part, 8- Conductor pattern, 9 Marker pattern for conductor pattern, 11.
Permalloy pattern, 12 Permalloy pattern marker pattern.

Claims (4)

[Claims] (1) A magnetic bubble memory element in which an ion implantation transfer pattern is formed in a magnetic thin film by ion implantation, and a conductive pattern and a magnetic material pattern are formed on the magnetic thin film by covering an insulating layer. A magnetic bubble memory element characterized in that a marker pattern for mask alignment of at least one of the ion implantation transfer pattern and the magnetic material pattern is formed in a raised shape. (2) The magnetic bubble memory device according to claim 1, wherein the raised marker pattern has at least two patterns, one for a conductor pattern and one for a magnetic material pattern. (3) The magnetic bubble memory element according to claim 1, wherein the raised marker pattern is formed using the mask material at the same time as forming the mask for forming the ion implantation transfer pattern. . (4) The magnetic bubble according to claim 1, wherein the raised marker pattern is generated by etching away the ion-implanted portion of the marker portion of the magnetic thin film to form a groove. memory element.