JPS62219286A - Magnetic bubble memory element - Google Patents

Abstract

PURPOSE:To simply and easily control an ion implantation transfer path by providing a control pattern which is formed simultaneously with a mask for ion implantation for the ion implantation transfer path. CONSTITUTION:The control pattern MP is constituted by forming the 1st rectangular control patterns MPA and the 2nd beltlike control patterns MPB which is less in width alternately and successively and also forming the 3rd control patterns MPC which is larger in pattern width on both sides of them. Control pattern MP1 are formed at a time on the same layer simultaneously with the formation of the mask MSK for ion implantation on a magnetic bubble magnetic film LPE. The mask MSK is removed after the ion implantation, but the control pattern MP is not removed and connected in series between bonding pads BP. The resistance value between the bonding pads BP connected to both end sides of the control pattern MP is measured and this resistance value is controlled at certain constant level. Consequently, the formation degree of the ion implantation transfer path I formed with the removed mask MSK is easily and simply controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic bubble memory element having a 72-ta pattern that controls the degree of formation of an ion implantation transfer path for transferring magnetic bubbles.

[Conventional technology]

In recent years, as a magnetic bubble memory element that has realized high density and high speed magnetic bubble memory, for example, Japanese Patent Application Laid-Open No. 57-18
As disclosed in Japanese Patent Application No. 6287, a group of minor loops that store information in the form of magnetic bubbles is configured with an ion implantation type magnetic bubble transfer path, and at least a part of the connecting portion with the major line or major loop that transfers the magnetic bubbles is constructed. A so-called hybrid type magnetic bubble memory element configured with a permalloy type magnetic bubble transfer path has been proposed.

[Problem that the invention seeks to solve]

The magnetic bubble transfer path (hereinafter referred to as ion implantation transfer path) using the ion implantation method used in this type of magnetic bubble memory element has a pattern period of about several μm, and the minimum pattern size is formed by an ultra-fine pattern of submicrons. be done. For this reason, when mass-produced, these dimensions will have some variation, and this variation in dimensions will greatly affect the transfer characteristics of the magnetic bubble. Therefore, strict control of the dimensions of these ultra-fine patterns is extremely important for mass production.

In addition, in the case of a permalloy magnetic bubble transfer path (hereinafter referred to as permalloy transfer path), since permalloy patterns ultimately exist, it is possible to manage them using these patterns. It can also be controlled electrically by measuring the resistance value of the magnetic bubble detector line.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic bubble memory element in which variations in the dimensions of ion implantation transfer paths can be easily and electrically managed at the final finished product level.

[Means for solving problems]

According to one embodiment of the present invention, the dimensions of the ion implantation transfer path can be controlled by providing a management pattern made of the same material and formed simultaneously with the ion implantation mask pattern in the space of the magnetic bubble magnetic film. A magnetic bubble memory device is provided.

[Effect]

In the management pattern of the present invention, the shape of the pattern remains as a tangible substance, so by measuring the dimensions of the pattern, it is possible to estimate the quality of the formation of the ion implantation transfer path.

〔Example〕

Next, embodiments of the present invention will be described in detail using the drawings.

FIG. 3 is an enlarged plan view illustrating a magnetic puzzle memory device according to the present invention. In the figure, m is a minor loop that stores information, RML is a read major line that transfers read information, and WNL is a write major line that transfers write information. Further, D is a bubble detector that converts magnetic bubbles into electrical signals, G is a bubble generator that generates magnetic bubbles, and R is a replicate gate that copies or transfers information of the minor loop m to the read measure line RML. T is a transfer gate that transfers the information on the light major line WML to the minor loop m, or a swap gate that simultaneously with the transfer, sweeps out the information on the minor loop m to the major line WML, so-called exchanging information between the two. In addition, GR surrounding these outer peripheries is a guardrail that prevents magnetic bubbles from entering from the outer periphery, BP is a bonding pad for connecting these transfer circuits with external circuits, and MP is a guard rail inside the magnetic bubble memory chip CHI. This is a management pattern formed outside the effective area indicated by a broken line. In addition, the replicate gate R, swap gate, and bubble generator G are controlled by whether or not a current is passed in a certain direction through a conductor in a separate layer arranged in a special relationship with the permalloy transfer pattern. The parts are indicated by thick solid lines. In addition, the minor loop m is formed by a magnetic bubble transfer path by ion implantation, and the read/measure line RML and write measure line WML are formed by permalloy magnetic bubble transfer paths, and a bias magnetic field HB is applied perpendicularly to these surfaces. The magnetic bubbles are transferred in the directions shown by the arrows by the rotating magnetic field applied in-plane.

Figures 4 and 5 show the permalloy transfer path mentioned above.

Each of the ion implantation transfer paths is shown, and the permalloy transfer path P shown in FIG.
A soft ferromagnetic thin film pattern PT, such as permalloy, is formed on top of the pattern PT via a spacer film sp such as 8102. A rotating magnetic field HR that rotates this pattern PT within this pattern plane
By magnetizing it, a moving magnetic pole Q is formed. The magnetic bubble B is attracted by this moving magnetic pole QK and is transferred along the pattern K in the direction of the arrow PR. On the other hand, in the ion implantation transfer path I, as shown in FIG. After forming the mask MSK for the magnetic bubble, by implanting ions I such as H2, He, No, etc. into the surface of the magnetic bubble magnetic film LPE, the ions are implanted into the area other than where the mask MSK was formed, forming an ion implantation layer. I
An ion implantation transfer pattern IPT is formed in the region where ON is formed and the mask MSK is formed.

Note that when H2 is used for ion implantation, it may be implanted after providing a passivation film ps as shown in FIG. 7 in order to prevent its evaporation. In either case, after ion implantation, the mask pattern MSK is removed, and an ion implantation transfer path I as shown in FIG. 5 is formed. By being magnetized by the rotating magnetic field HR that rotates within, a magnetic pole Q called a charged wall is generated that moves along the pattern IPT. The magnetic bubbles are attracted to this charged wall and transferred along the pattern IPT in the direction of the arrow PR.

As shown in FIG. 4, the ion implantation transfer path I is different from the permalloy transfer path P in that it does not have the gap portion 2 between the patterns, and the ion implantation layer ION
is formed inside the bubble magnetic film LPE and is closely spaced from the magnetic bubble B, which provides excellent characteristics for high density.

As mentioned above, the ion implantation transfer path I, which has such features and is suitable for high-density processing, has the following characteristics: (13) After completion, the ion implantation mask MSK is removed, and in the end, it does not remain on the magnetic bubble memory element at all. .

(2) Since the magnetic bubble is formed inside the magnetic film LPE, the pattern IPT cannot be observed under a microscope.

(3) It cannot be easily and easily measured electrically.

Due to mass production, it is impossible to control the dimensions.

Therefore, in the present invention, the management pattern MP described above is
As shown in FIG. 1, the rectangular first management pattern MPA
and a band-shaped second management pattern MPB with a small pattern width.
A third management pattern MPC with a larger pattern width is formed on both ends of the ion implantation transfer path! A management pattern MPI having almost the same length as , and a second management pattern MPB' between the first management pattern yMPB and a modification example thereof shown in FIG.
A management pattern M formed by further increasing the pattern length of
P2 is preferred, and these management patterns MPI, MP
2 is a magnetic bubble magnetic film LPE as explained in FIG.
They are formed all at once on the same layer at the same time as the ion implantation mask MSK formed of a thin film of Au or the like thereon. After the ion implantation, the mask MSK is removed, but the management pattern MP is not removed, and the bonding pads BP are connected in series between each other.

According to such a configuration, the resistance value between the bonding pads BP connected to both ends of the management pattern MP is measured, and this resistance value is managed at a certain level, thereby removing the resistance. The degree of formation of the ion implantation transfer path I formed using the mask MSK can be easily and easily controlled. In addition, since this management pattern MP is formed of a thin Au film, it is tangible and visible, and its dimensions can be measured.Therefore, this measured dimension value can be managed at a certain level. Similarly, it becomes possible to manage ion implantation transfer route construction.

In addition, in the embodiment described above, the management pattern MPt
-Although the case where the pattern is formed using a thin metal film such as Au has been described, the present invention is not limited to this, and can also be applied to a dimension measuring means for measuring the distance between pattern edges even when the pattern is formed using a thin film such as a polymer resin. The same effects as mentioned above can be obtained by allowing for better management.

Further, in the above-mentioned embodiment, the case where the management pattern MP is provided in the side space of the magnetic bubble detector has been described, but the present invention is not limited to this. It goes without saying that the same effect as described above can be obtained even if it is provided in a space such as around the area.

〔Effect of the invention〕

As explained above, according to the present invention, a management pattern is provided which is formed simultaneously with the ion implantation mask of the ion implantation transfer path, so that the management of the ion implantation transfer path is easy and The present invention has extremely excellent effects in that a magnetic bubble memory element that can be easily realized and has high quality and reliability can be obtained.

[Brief explanation of drawings]

FIG. 1 is an enlarged plan view of a management pattern for explaining one embodiment of a magnetic bubble memory element according to the present invention, FIG. 2 is an enlarged plan view of a management pattern for explaining another embodiment of the present invention, FIG. 3 is a plan view showing a magnetic bubble memory element according to the present invention, FIG. 4 is a perspective view of a main part showing a permalloy transfer path, FIG. 5 is a perspective view of a main part showing an ion implantation transfer path, and FIG. FIG. 7 is a perspective view of a main part explaining a method of forming an implantation transfer path. FIG. 7 is a perspective view of a main part explaining another method of forming an ion implantation transfer path. LPE...magnetic bubble magnetic film, I/self/fist ion, ION...ion implantation/il, IPT/
...Ion implantation transfer pattern, ■...Ion implantation transfer path, MSK...Mask for ion implantation, B...Magnetic bubble, MP. MPI, MP2... Management pattern, MPA...
First management pattern, MPB...Second management pattern, MPC...eThird management pattern, BP...
Φponding pad.

Claims (1)

[Claims] 1. An ion implantation transfer path for transferring magnetic bubbles to the surface of the magnetic bubble magnetic film, and a management method that is formed simultaneously with an ion implantation mask pattern of the ion implantation transfer path on the surface of the magnetic bubble magnetic film. A magnetic bubble memory element characterized by being provided with a pattern. 2. The magnetic bubble memory device according to claim 1, wherein the management pattern is provided outside the effective area. 3. The magnetic bubble memory device according to claim 1, wherein the management pattern is formed of a metal thin film and connected to a bonding pad.