JPS61210508A - Manufacture of thin-film magnetic head - Google Patents

Abstract

PURPOSE:To improve the production yield of a thin-film magnetic head of double-layer spiral structure by setting the side wall angle of a layer of the 1st layer to 40-70 deg. and patterning photoresist which forms coil conductors of the 2nd and succeeding layers. CONSTITUTION:A lower magnetic layer 2 is formed of 'Sendust(R)' or amorphous material on a magnetic or nonmagnetic base plate and the 1st insulating layer 3 is formed of SiO2, etc., thereupon by sputtering and vapor deposition. Photoresist is applied further thereupon, and patterned by exposure and development. This resist is heat-treated to form hemispherical resist 10. This resist is used as a mask to form a coil conductor. In this case, the side wall angle of the coil of the 1st layer is set to 40-70 deg. and the angle of incidence of an ion beam is set to 30-40 deg. for ionmilling. Consequently, the 1st layer coil and the 2nd layer coil 6 are prevented from short-circuiting and the thin-filmmagnetic head of multi-layered spiral structure is productedat high yield.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a method for manufacturing a thin film magnetic head, and particularly to an improvement in a method for forming a multilayer spiral coil of two or more layers for a thin film magnetic head.

(Prior Art) Thin-film magnetic heads currently have a two-layer spiral structure in order to improve recording and reproducing efficiency by increasing the number of windings. The structure of a conventional two-layer spiral thin film magnetic head is shown in FIGS. 1 and 2. First, a lower magnetic layer 2 made of sendust or amorphous is formed on a magnetic or nonmagnetic substrate 1, and a first insulating layer 3 made of 5iOz or the like is formed thereon by sputtering, vapor deposition, or the like. Next, a first layer coil conductor 4 made of Cu is placed thereon.
is formed, and then a second insulating layer 5 made of, for example, $102 is formed.
is further formed thereon, then a second layer coil conductor 6 is formed between the first layer coils 4, and S! A third insulator JI8 made of Oz or the like is formed, and the upper magnetic pole 9 and the lower magnetic pole 2
Taper etching is performed to open a window for magnetic coupling between the two, and then a gap layer 7 made of 5fOz or the like is formed, only the gap layer 7 in the rear gap portion is etched, and on top of that a gap layer 7 made of sendust or amorphous is formed. An upper magnetic layer 9 is formed. In this way, a thin film magnetic head with a two-layer spiral structure is manufactured. However, the thin film magnetic head manufactured in this manner has the following problems. This will be explained in detail using FIG.

That is, when the photoresist 9 is formed on the coil conductor layer 4 made of Cu, the sidewall angle α of the patterned photoresist is about 75° to 80°. (FIG. 3(a)) When etching the coil conductor layer 4 made of CIJ by ion milling using a resist having such a sidewall angle as a mask, the ion beam incidence angle should not be smaller than 25°. A shadow effect of the ion beam occurs on the photoresist, resulting in narrow conductor spacing after etching and short circuits between adjacent coils. (Fig. 4) Also, in order to prevent the coil conductor from shorting with adjacent coils,
25 as the ion beam incident angle that does not cause the adow effect.
If the etching angle is less than 75°, the angle of the coil will be 75° due to the influence of the sidewall angle of the photoresist mask.
~80°. (FIG. 3(b)) An insulating layer 5 of 5iOz or the like is formed on the coil thus formed by sputtering or vapor deposition, and then a second layer coil conductor is formed thereon by similar means. Forms Cu. Then, a photoresist 10 for forming a second layer coil conductor is formed between the first layer coil conductors 4. (Figure 3(d))
When the photoresist 10 thus formed is used as a mask and etching is performed at an ion beam incident angle smaller than 25° in the same manner as in the first layer coil formation, the sixth
As shown in the figure, when the angle of the base level difference is about 756 to 806, the etching time is several times longer than the time required to completely etch a certain film thickness on a plane (α=0). Therefore, even if etching is completed on the plane, the slope portion shown by the arrow in FIG. 3(d) is not etched and CuN remains. In other words, re-deposition occurs in this region rather than being etched, and as the etching progresses, the C(I) film is sputtered onto the sidewalls, leaving CIJ on the sidewalls. If it remains, a short circuit will occur between the second layer coils as shown by the arrows in Figure 1, and even if a two-layer spiral structure is used, the second layer coil conductor will be short-circuited. There was a drawback in that the yield rate was very low when producing heads.

(Objective of the Invention) An object of the present invention is to provide a method for manufacturing a thin film magnetic head that improves yield by eliminating the short circuit described above.

(Structure of the Invention) That is, in the manufacturing method according to the present invention, in a thin film magnetic head having a spiral structure of two or more layers formed using Cu as a coil conductor, the side wall angle of the first layer coil is set to 40° to 70°.
After patterning the photoresist for forming the second or higher layer coil conductor,
By heat-treating at a temperature above ℃ but below 200℃ and etching with an ion beam incidence angle of 30° or above and below 40°,
The present invention is characterized in that thin film magnetic heads with a spiral structure of WJ or higher can be produced with good yield.

(Example) An embodiment of the present invention will be described in detail using FIG.

First, a lower magnetic layer 2 made of sendust or amorphous is formed on a magnetic or nonmagnetic substrate 1, and a first insulating layer 3 made of 8102 or the like is formed thereon by sputtering, vapor deposition, or the like. Next, Cu 4, which will form the first layer coil conductor, is formed by sputtering, vapor deposition, or the like. Furthermore, photoresist (Sibley I
AZ 1350J) is applied and patterned by exposure and development. The resist formed in this way is
The photoresist is softened by heat treatment at 30° C. or more and less than 200° C. for about 30 minutes, and becomes a resist 9 having a hemispherical shape. (FIG. 7(a)) The reason why the temperature of the heat treatment is set to be less than 200° C. is that if the heat treatment is performed at a temperature of 200° C. or higher, the resist cannot be peeled off only with a solvent (for example, acetone) after etching. Also, the angle of the resist at this time is about 40" to 70 degrees. Since the coil conductor is formed using the resist formed in this way as a mask, if the angle of the resist is 40 degrees, C (I) is etched. When performing ion milling, perform ion milling at an angle such that the ion beam incidence angle is 50° or less.If the ion beam incidence angle is 50° or more, a shadow effect of the ion beam will occur due to the photoresist, and the coil conductor will become narrowed. If the ion beam incident angle is less than 50°, the sidewall angle of the etched first layer coil conductor should be formed at the angle of the photoresist. Therefore, the angle is about 40” to 70°.

S on the first layer coil conductor 4 formed in this way.
! A second insulating layer 5 made of Oz or the like is formed by sputtering or vapor deposition, and furthermore, Cu for forming a second layer coil conductor is formed thereon by a similar method. A photoresist 10 for forming a second layer coil conductor is patterned on the sputtered film or vapor deposited film of the CIJ thus formed, and heated at a temperature of 130° C. or higher to 200° C. in the same manner as when the first layer coil 4 was formed. Heat treated below ℃. Thereafter, ion milling is performed using the resist 10 formed into a hemispherical shape by heat treatment as a mask to form the second layer coil 6. At this time, the ion beam incidence angle is 30° or more.
It needs to be below 0°.

The reason for this will be explained using FIGS. 5 and 6.

First, Fig. 6 shows "" at various ion beam incident angles β.
This figure shows the difference in etching time depending on the sidewall angle α of the F membrane step. Here, the etching time is taken as a reference when the ion beam incident angle is −0° and there is no step and α=0>. For example, at an ion beam incident angle of β-〇°, if the angle of the base step is about α-85°, no matter how much etching is done, the CU at this step cannot be removed, and the second
There is a drawback that short circuits occur between layer coils. Also,
When the ion beam incident angle is β=60° and the angle of the base step is about α=85°, the Cu at α=85° will be etched in about half the etching time of a flat surface. In other words, if you try to completely etch the Cu film on a plane, you will end up etching a portion of the insulating layer 5 shown by the arrow in Figure M7 (d). Even if the two-layer coil 6 is formed, there is a drawback that the insulating layer 5 is etched at this time, resulting in a short circuit between the first layer coil 4 and the second layer coil 6.

therefore! In order to successfully form the 21 coil 6, since the side wall angle of the first layer coil 4 is 40° to 70°, the second
The side wall angle of the layer coil 6 is 40° to 70°, which is the same as the base level difference.
Therefore, ion milling may be performed at an ion beam incident angle of 30° or more and 40° or less, which completes the etching in the same etching time at a step angle α=O, that is, a plane and side wall angle of 40° to 70′.

(Effects of the Invention) As described above, according to the present invention, in a thin film magnetic head having a multilayer spiral structure using Cu as a coil conductor,
The side wall angle of the layered coil conductor was set to 40° to 70", and after patterning the photoresist for forming the second and higher layer coil conductors, heat treatment was performed at 130°C or higher and lower than 200°C, so that the ion beam incident angle was 30°. By performing ion milling at an angle of 40 degrees or less, it is possible to prevent short circuits between the first layer coil and the second layer coil, and between the second layer coils. This has the remarkable effect that magnetic heads can be produced with high yield.

[Brief explanation of the drawing]

Figure 1 shows the conventional two-layer spiral coil structure.
1. Figure 2 is a cross-sectional view taken along line A-A' in Figure 1. Figure 3 is a process diagram for forming a conventional two-layer spiral coil. Figure 4 shows the shadow effect of the ion beam. 5 and 6 are diagrams showing the difference in etching time due to differences in the side wall angle α of the base step at various ion beam incident angles β, and FIG. 7 is a diagram showing the process of forming a two-layer spiral coil according to the present invention. FIG. 1...Substrate 2...Lower magnetic layer 3...
-First layer insulating layer 4...First layer coil 5...Second layer insulating layer 6...Second layer coil 7...Gap layer 8...Third insulating layer 9...Top magnetic layer
10...Photoresist 11...5hadoi
v area 12...Ion beam α...Side wall angle of step β...Ion beam incident angle to...Film thickness etched on plane t...Film thickness etched on slope 33 1 Figure 2 Figure 2 Four Mayo Shadows -+,) L Demand Shi (Voluntary) Procedure Amendment Layer Commissioner of the Patent Office June 19, 1985 1. Indication of the Case Patent Application No. 1988-52044 2. Name of the Invention 7II Manufacturing method of film magnetic head 3 Relationship with the case of the person making the amendment Patent applicant Location 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture Name Name
Fuji Photo Film Co., Ltd. 4, Agent: 5-2-1 Roppongi, Minato-ku, Tokyo 1) On page 4, line 8 of the specification, ``formed'' is corrected to ``formed.'' 2) Correct the cylinder figures 4 and 7 in the drawings as attached. Figure 4

Claims (1)

[Claims] In a thin film magnetic head with a multilayer spiral structure using Cu for the coil conductor, the step angle of the first layer coil conductor was set to 40° to 70°, and photoresist was further patterned to form the second and higher layer coil conductors. A method for manufacturing a thin-film magnetic head, characterized in that the photoresist is then heat-treated at a temperature of 130° C. or more and less than 200° C., and ion milling is performed at an ion beam incidence angle of 30° or more and 40° or less.