JPS61246992A - Method for manufacturing magnetic bubble memory element - Google Patents

Abstract

PURPOSE:To improve an S/N ratio, to enlarge an action area and to give high performance to a memory element by forming a detecting part including a stretcher by approaching said part to a magnetic garnet layer. CONSTITUTION:A conduction pattern 13 is formed on the magnetic garnet layer LPE 11, threreon an insulating layer 14 is coated and thereon a resist pattern 22 excluding the part where the detecting part 16 including the stretcher of a magnetic bubble is formed is produced. Under the atomsphere including oxide O2 plasma is irradiated on at least the formation part of the detecting part 16. Then the remainding layer 24 of the resist pattern 22 is removed and thereon the detecting part 16 made of a magnetic material and other pattern 17 are formed. Accordingly, even when an interval between the LPE 11 and a transfer path 17 is several thousand Angstrom , is hardly affects the characteristics of the element and the interval (thickness of the insulating layer 13) between the LPE 11 and the detecting part 16 reduces the S/N of the element.

Description

[Detailed Description of the Invention] [Summary] When manufacturing a magnetic bubble memory element in which a magnetic bubble generator, a transfer path, a detection section including a stretcher, etc. are formed on an LPE surface, an iodizing treatment using 0□ plasma is performed. By utilizing the detection section including the stretcher, the L
By forming it close to the PE surface, high performance of the magnetic bubble memory element has been achieved.

[Industrial application field]

The present invention relates to a method of manufacturing a magnetic bubble memory device.

Magnetic thin film (LP) such as garnet with uniaxial magnetic anisotropy
When a perpendicular bias magnetic field of an appropriate magnitude is applied to the E) plane, a cylindrical magnetic domain (magnetic bubble) is generated.

A magnetic bubble memory device that utilizes such magnetic bubbles and has advantages such as being nonvolatile, being an all-solid-state element, capable of large capacity, and relatively high speed is a magnetic bubble memory device that utilizes magnetic bubbles. A memory element is mounted on a substrate made of ceramic or the like, and the substrate has a drive coil that applies a horizontal rotating magnetic field to the magnetic bubble, and a permanent magnet that applies a bias magnetic field in the vertical direction of the element and a hold magnetic field in the horizontal direction. etc., and the element is housed in a package, and the element is located at the center of the drive coil.

[Conventional technology]

FIG. 5 is a perspective view showing an example of the main configuration of a magnetic bubble memory device.

In FIG. 5, the magnetic bubble memory device 1 includes a magnetic bubble memory element 2, a substrate 3 on which the element 2 is mounted and has a Y-shape in plan view, and a rectangular X coil 4 and an X coil 5 fitted into the substrate 3. A plurality of lead terminals 6 each having one end soldered to one opposing side of the substrate 3, and a pair of permanent magnets 7 facing each other in the vertical direction of the element 2. Magnetic shunt plate 8 and shield case 9
It is made up of etc.

In such a magnetic bubble memory device 1, the element 2 has a magnetic garnet layer (LPE) formed on the top surface of a garnet substrate, and a detection unit including a bubble generator and a bubble stretcher, a replicator, and an extinguisher are formed on the magnetic garnet layer (LPE).

Information processing elements such as bubble transfer channels and various transfer gates, external connection electrodes connected to the elements, etc. are patterned, and a protective layer with the electrodes exposed is deposited thereon. After mounting on the substrate 3, the other end of the conductor pattern formed on the substrate 3 and having one end connected to each lead terminal 6 and the connection electrode are wire bonded.

FIG. 6 is a partially cutaway and enlarged side view of the element 2,
11 is LPE, 12 is an insulating layer (SiOx layer) deposited on LPEIIO, 13 is a conductor pattern such as a transfer gate or a generator gate formed on the insulating layer 12, 14 is an electrical insulating layer, and 15 is a Color edge layer (Si
16 is a detection section including a bubble stretcher patterned on one color edge [14], 17 is a bubble transfer path patterned at the same time as the detection section 16 including a stretcher, and 18 is a coating layer on top of them. The insulating protective layer that has been deposited, the detection section 16 including the stretcher, the transfer path, etc. 17 is formed by selectively dissolving a thin film made of a magnetic material (permalloy, etc.).

The insulation N14 of the element 2 also has the role of leveling the unevenness caused by the conductor pattern 13, and the thickness of the insulation layer 14 made of polyladder organosiloxane resin (Teflon resin, hereinafter referred to as PROS) etc. Because of the leveling, the thickness is thicker than required for electrical insulation, and is generally several thousand.

[Problem that the invention seeks to solve]

In the above element 2, conventional insulation [
14. An insulating layer 14 made of, for example, broth was deposited by spin cord means and formed to a uniform thickness. Therefore, L
The distance between the P Ell and the transfer path 17 does not affect the characteristics of the device even if there are several thousand people, but the distance between the L Pell and the detection section 16 including the stretcher (thickness of the insulating layer 13) S/N is reduced.

Incidentally, one drawback of the magnetic bubble memory element is that the S/N is low, and the conventional S/N is about 3.

Measures for Solving Problem c] The above problem can be solved by forming a conductor pattern (13) on the L P E (11) surface, depositing an insulating layer (14) on it, and Detection unit (16) including a magnetic bubble stretcher
) Resist pattern (22) excluding the part where the pattern is formed
02 plasma is irradiated to the detection part (16) forming part including at least the stretcher in an oxygen-containing atmosphere, and then, after removing the remaining layer (24) of the resist pattern (22), The detection part (16) and its part (7) are made of magnetic material.
) The problem is solved by a method of manufacturing a magnetic bubble memory element by forming another pattern (17).

[Effect]

According to the above means, by thinning a part of the insulating layer and forming a detection part including a stretcher in the thin part,
Without impairing the conventional insulation properties of the insulating layer, the detection section including the stretcher can be formed closer to the LPE than before, and the SZN ratio of the device can be improved.

〔Example〕

The present invention will be explained in detail below using the drawings.

Figures 1 (a) to (g) are partially enlarged and cutaway side views to explain the process of making a magnetic bubble element according to an embodiment of the present invention, and Figure 2 is a reduction in plasma processing time and broth. Fig. 3 is a relational diagram obtained by actual measurement of the relationship between the plasma output and the amount of reduction in broth, and Fig. 4 shows the relationship between the plasma output and the amount of reduction in broth obtained by actual measurements. It is a relationship diagram obtained by actual measurement of the relationship between the amount of reduction in broth and the amount of reduction in broth.

In FIG. 1, in which the same reference numerals are used for parts common to those in FIG. 6, 21 is a resist layer deposited on the insulating layer 14, 22 is a resist pattern obtained by removing unnecessary parts of the resist layer 21,
23 is an insulating layer obtained by thinning a portion of the insulating layer 14 by plasma treatment, and 24 is a remaining layer of the resist pattern 22 which has been thinned by the plasma treatment.

In FIG. 1(A), a resist layer 21 is deposited on an insulating layer 14 deposited in the same process as in the conventional method.

Next, unnecessary portions of the resist layer 21, ie, portions of the resist layer 21 where the detection portion including the stretcher is to be formed, are dissolved away to form a resist pattern 22 as shown in FIG. 1(U).

Next, when the upper surface of the resist pattern 22 and the exposed insulating layer 14 are irradiated with 0□ plasma in an oxygen-containing atmosphere, the irradiated area becomes iodized (asher) as shown in FIG. 1(c). The insulating layer 23 and the resist pattern remaining layer 24 are formed.

Therefore, after the remaining layer 24 is dissolved away with a solvent such as acetone as shown in FIG. 1(D), an insulating layer 15 is deposited as shown in FIG. 1(N).

Next, by forming a detection section 16 including a stretcher and a bubble transfer path 17 thereon by the same means as in the conventional method, the detection section 16 including a stretcher is formed as shown in FIG.
is formed closer to the LPELL than the bubble transfer path etc. 17.

Next, as shown in FIG. 1(G), an insulating protective layer 18 is deposited to complete the formation of various patterns of the magnetic bubble memory element.

The plasma treatment using broth for the insulating layer 14 will be explained below based on actual measurement data (with reference to FIGS. 2 to 4).

In Figure 2, the horizontal axis is the plasma treatment (irradiation) time (x
100 minutes), and the vertical axis is the amount of decrease in the film thickness of the insulation 14 (x 10
When the insulating layer 14 is irradiated with plasma in air, its film thickness decreases significantly between 0 and about 60 minutes, and the rate of decrease thereafter becomes extremely low. However, in FIG. 2, the initial thickness of the layer 14 is 3.
300 people, atmosphere vacuum level 1.5, plasma output 4
This is based on actual measurement data with 00 constant.

In Figure 3, the horizontal axis is plasma output (X100W),
The vertical axis is the amount of decrease in the film thickness of the insulation 114 (X100 people),
The plasma output reaches approximately 200 W, and even if the output is increased, the film thickness reduction efficiency tends to decrease somewhat. However, FIG. 3 is based on actual measurement data in which the initial thickness of the insulating layer 14 is 2700 mm, the degree of vacuum of the atmosphere is 1.5, and the plasma processing time is 60 minutes as the plasma processing conditions.

In Fig. 4, the horizontal axis is the thickness of the insulation IJ14, which is 1000
The vertical axis represents the amount of decrease in the thickness of the insulating layer 14 (X100 people), and the thicker the insulating layer i14, the greater the amount of decrease in the thickness.

However, Fig. 4 is based on actual measurement data where the plasma processing conditions were constant: atmospheric vacuum level of 1.5 Torr, plasma output of 400 W, and plasma processing time of 60 minutes, and the thickness of the insulating layer i14 was It is necessary to prioritize the electrical characteristics and the role of leveling the unevenness of the base.

Therefore, the plasma treatment for forming the insulation N23 according to the process shown in FIG. 1 is set within one hour from FIG. 2, and the amount of film thickness reduction is predicted from FIGS. 3 and 4 and carried out.

〔Effect of the invention〕

As explained above, according to the present invention, the detection section including the stretcher is formed closer to the LPE than the bubble transfer path formed in the same process, so that the influence of magnetic noise etc. on the detection section is reduced. , S/H can be improved and the operating range can be expanded, which has the effect of improving the performance of the magnetic bubble memory element.

[Brief explanation of the drawing]

Figures 1 (a) to (g) are partially enlarged and cutaway side views to explain the process of making a magnetic bubble device according to an embodiment of the present invention, and Figure 2 is a reduction in plasma processing time and broth. Figure 3 is a diagram showing the relationship between plasma output and the amount of reduction in broth determined by actual measurements. Figure 4 is a diagram showing the relationship between plasma output and the amount of broth reduction determined by actual measurements. Figure 4 shows the broth film thickness when the plasma processing conditions are constant. Figure 5 is a perspective view showing an example of the main configuration of a magnetic bubble memory device, Figure 6 is a partially cutaway enlarged view of element 2 according to the prior art. This is the side view. In the figure, 2 is a magnetic bubble memory element, 11 is an LPE, 13 is a conductor pattern, 14, 23 is an insulating layer, 16 is a detection section including a stretcher, 2 is a resist layer, 22 is a resist pattern, 24 is a resist pattern Residual layer, (4' Graduation 1 factor x 700 Kaplasma effect J Seisho no Sho (3) 4th area

Claims (1)

[Claims] A conductor pattern (13) is formed on the surface of the LPE (11), an insulating layer (14) is deposited on it, and a detection part (16) including a magnetic bubble stretcher is formed on the conductor pattern (13).
) Resist pattern (22) excluding the part where the pattern is formed
, irradiate O_2 plasma to the detection part (16) forming part including at least the stretcher in an oxygen-containing atmosphere, and then remove the remaining layer (24) of the resist pattern (22), and then apply a layer on top of it. A method for manufacturing a magnetic bubble memory element, characterized in that the detection portion (16) and other patterns (17) are formed of a magnetic material.