JPH0244511A - Production of thin film magnetic head - Google Patents

Abstract

PURPOSE:To shorten the time for film formation of a mask layer consisting of an inorg. material by etching the inorg. mask layer and upper core to a prescribed shape down to the position in the middle of the thickness direction thereof with a resist mask layer as a mask, then irradiating the layer again with an ion beam. CONSTITUTION:The thin film magnetic head is produced by forming a lower core 2 consisting of a magnetic material and an insulating layer 3 on a nonmagnetic material 1, then providing an insulating layer 5 interposed with a coil 4 consisting of a conductive material therein, laminating the upper core 6 consisting of a magnetic material connecting at one end to the lower core 2 thereon and forming the upper core 6 to the prescribed shape. The mask layer 23 consisting of the inorg. material covering the core is formed on the upper core 6 and the resist mask layer 8 of the prescribed shape is formed on the mask layer 12. The layer is then irradiated with the ion beam 9 by which the mask layer 23 and the upper core 6 are etched down to the prescribed position in the thickness direction thereof. The remaining mask layer 8 and the thin film 13 are removed and the upper core 6 is again irradiated with the ion beam 9, by which said core is etched to the prescribed shape. The time for the film formation of the mask layer 12 consisting of the inorg. material is shortened in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a thin film magnetic head for exchanging signals with a magnetic storage medium in a magnetic disk device or the like.

[Prior Art] Thin-film magnetic heads are smaller than conventional magnetic heads using bulk cores, so the track width can be made smaller, and recording in a high frequency band is possible. In either case, higher density can be expected. Therefore, it is used to take advantage of its advantages in floating magnetic heads of magnetic disk drives.

FIG. 3 shows an example of such a thin film magnetic head. This thin film magnetic head consists of a lower core 2 made of a magnetic material formed on a non-magnetic substrate l, and an insulator 3 for forming a gap formed on top of the lower core 2. An insulating layer 5 with a plurality of coils 4 interposed therebetween, and Ni-Fe, Fe-5i-
The upper core 6 made of a magnetic material such as AI or Co-based amorphous is sequentially formed to have a total thickness of about 15 μm.
are magnetically connected at their respective rear ends to constitute a back core portion (not shown), and are opposed to each other via a bipedal insulator 3 to form a head gap portion 7.
Configure. The coils 4 are arranged concentrically around the back core section, and by energizing each coil 4, a magnetomotive force is generated in the lower core 2 and the upper core 6, and this magnetomotive force causes a flow to flow. Magnetic flux leaks from the rad gap portion to perform recording on a magnetic storage medium (not shown).

In the manufacturing process of such a thin film magnetic head, the upper core 6 is formed over the entire surface of the insulating layer 5 by sputtering or vapor deposition, and then etched into a predetermined shape by ion milling through the resist mask layer 8. However, conventionally, two types of etching have been provided: a method using only the resist mask layer 8 as a mask, and a method using an inorganic mask.

Hereinafter, double pressing will be explained using the head gap portion 7 as an example, with reference to FIGS. Apply over the entire core 6,
A Renost mask layer 8 having a predetermined shape is formed by photolithography.

Next, as shown in FIG. 4(a), the ion beam 9 is irradiated toward the upper core 6 at an incident angle of 0-0° to produce a fourth beam.
As shown in Figure (b), the upper core 6 is covered with a resist mask layer 8.
Etch leaving the part covered by. Thereafter, the remaining resist mask layer 8 is removed to form the upper core 6 in a predetermined shape.

On the other hand, when using an inorganic mask, as shown in Fig. 5 (
As shown in a), an inorganic mask layer 10 made of Ti or the like is first formed over the entire surface of the upper core 6 by sputtering or the like, and then a resist mask layer 8 having a predetermined shape is formed in the same manner as above. Next, as shown in FIG. 5(b), the inorganic opaque mask layer 10 is etched using the resist mask layer 8 as a mask to form a predetermined shape.
remove. Then, as shown in FIG. 5(c), the ion beam 9 is irradiated toward the upper core 6 at an incident angle θ=θ°, and as shown in FIG. 5(d), the inorganic mask layer 10 is used as a mask. The upper core 6 is etched into a predetermined shape.

[Problems to be Solved by the Invention] By the way, each of the conventional upper core forming methods described above has the following drawbacks.

First, when using the resist mask layer 8 as a mask for etching the upper core 6, the incident angle of the ion beam 9 is set to θ = 0°, which is generally accepted for processing accuracy. The phenomenon of reattachment of the upper core 6 to the resist mask layer 8 due to the rebound of the upper core 6 is unavoidable. This re-adhesion phenomenon has the property of occurring more clearly as the film thickness of the upper core 6 becomes thicker after being etched, and if it is a light adhesion, it is not a problem as it can be removed in a later cleaning process, but it is not a problem especially when the resist In the step portion of the upper core 6 where the mask layer 8 is thick, that is, near the back core portion 7, the side surface of the Renost mask layer 8 is entirely covered with a thin wall 1, as shown in FIG. 4(b).
1, making it difficult to remove in the subsequent cleaning process, resulting in a thin wall as shown in Figure 4 (c)! l
It is a hot topic that is left behind and spoils the appearance of the product.
This may have an impact on film formation in post-processes, and may even have an impact on performance.

Furthermore, when the inorganic mask layer IO is used as a mask for etching the upper core 6, the inorganic mask layer IO is formed thinly and uniformly by sputtering or the like, and no local increase in thickness occurs. Although the redeposition phenomenon does not occur during etching of the core 6, it was difficult to etch the inorganic mask layer 1O without etching the upper core 6. Furthermore, when etching the upper core 6, the inorganic mask layer 10 itself is etched one by one, so the film thickness of the inorganic mask layer 10 must be set to a certain level so that it does not disappear before the etching of the upper core 6 is completed. It was necessary to increase the thickness, and the time required for film formation tended to be long.

This invention was made against this background, and is based on the premise that a resist mask layer and an inorganic mask layer are used together as an etching mask, without impairing the advantage of being able to eliminate the effects of re-deposition, and It is an object of the present invention to provide a method for manufacturing a thin-film magnetic head that does not require a special etching method and can further reduce the time required to form an inorganic mask layer.

[Means for Solving the Problems] In order to solve the above problems, the present invention forms an upper core into a predetermined shape according to the following steps.

(1) A mask layer forming step of forming an inorganic mask layer covering the upper core on the upper core and forming a resist mask layer having a predetermined shape on the inorganic mask layer.

(2) A primary etching step in which the inorganic mask layer and the upper core are etched into a predetermined shape up to a midway position in the thickness direction by irradiating the inorganic material mask layer with an ion beam while covered with the resist mask layer.

(3) A resist removal step of removing the resist mask layer on the inorganic mask layer etched into a predetermined shape by the primary etching step.

(4) By irradiating the ion beam again while covered with the inorganic mask layer etched into the predetermined shape,
A secondary etching process for etching the upper core into a predetermined shape.

[Operation] In the above method, the resist mask layer is used as a mask in the primary etching process to etch the upper core into a predetermined shape up to a midway point in the thickness direction, so a special etching method is required to etch the inorganic mask layer. In addition, since the amount of etching of the upper core in the secondary etching process is reduced, the thickness of the inorganic mask layer can be made thinner.Furthermore, as the upper core is etched by the ion beam, the inorganic mask layer is not deposited on the resist mask layer. The amount of deposits is reduced.

[Example] Hereinafter, the present invention will be described in detail with reference to FIGS. 1(a) to 2). Note that this embodiment is an example of forming the upper core 6 into a predetermined shape to be connected to a thin-film magnetic head having the structure shown in FIG. do.

In this embodiment, in order to form the upper core 6 into a predetermined shape, as shown in FIG.
Then, a photoresist is applied onto the inorganic mask layer 12 by a spin code method or the like, and a resist mask layer 8 having the same shape as the desired upper core shape is formed by photolithography (mask layer creation step). . In addition,
Inorganic materials used for the inorganic mask layer 12 include Ti,
Examples include Or, 0% Alt03, and the like.

After the resist mask layer 8 is created, the inorganic mask layer 12 is then irradiated with an ion beam 9 to form the inorganic mask layer 12 into a predetermined position using the resist mask layer 8 as a mask, as shown in FIG. 1(b). In addition to etching into the shape, etching is also performed to the middle of the upper core 6B in its thickness direction (primary etching step). At this time, the etching depth of the upper core 6 is determined so that the thin wall 13 formed on the side surface of the resist mask layer 8 due to irradiation with the ion beam 9 remains within a range that can be reliably removed by subsequent cleaning. It will be done.

Further, the etching in this case is based on a so-called ion etching method in which etching is performed by accelerating ions generated in plasma using an electric field.

Once the upper core 6 has been etched by a predetermined amount,
As shown in FIG. 1(c), the remaining resist mask layer 8
Then, the thin wall 13 is removed, and the remaining inorganic mask layer 12 is exposed on the surface (renost removal step). Then, using the inorganic mask layer 12 exposed on the surface as a mask, the ion beam 9 is irradiated again to etch the entire upper core 6 except for the part covered with the inorganic mask layer 12, as shown in FIG. 1(d). As shown in FIG. 3, the upper core 6 is formed into a predetermined shape (secondary etching step).

As described above, in this embodiment, in the primary etching step of etching the inorganic material mask layer 12 into a predetermined shape, not only the inorganic material mask layer 12 but also the upper core 6 is etched to a position midway in the thickness direction. Equipment mask layer 1
In forming the inorganic mask layer 1 into a predetermined shape, a well-known etching method such as an ion etching method can be used without using a special etching method.
Since the etching method for the upper core 6 in the secondary etching step using the mask 2 as a mask is also reduced, the thickness of the inorganic mask layer 12 can also be made thinner than before.

The etching of the upper core 6 in the primary etching process is performed by etching the i-V wall 1 formed on the resist mask layer 8.
3 is carried out within a range that can be reliably removed by cleaning accompanying subsequent resist removal, so that the upper core 6 formed into a predetermined shape will not be affected by the redeposition phenomenon.

Here, the inorganic mask layer 1 formed in the mask layer creation process
To explain the relationship between the film thickness of the upper core 6 and the amount of etching of the upper core 6 etched in the primary etching process, as shown in FIG. 7, the thickness of the inorganic mask layer 12 is L3, and the etching rate of the upper core 6 and the inorganic mask layer 12 with respect to the ion beam 9 is RA, n, respectively. Etching allowable in the primary etching step However, if the maximum etching nail capable of removing the thin wall 13 is t168, then the amount of etching in the primary etching step is the maximum etching ffl.
Since t IIIK must not be exceeded, j ++ j 3 t 2< tfflax
-C1) is obtained, and in the secondary etching process, since the inorganic mask layer 12 must remain at the end of etching the upper core 6, L2・Ra/ RA < t3...
The conditional expression (2) is obtained, and the following relationship is derived from these expressions (1) and (2).

To give a specific example, tI=2.5umSRe/nA0
．． 5. If t , , , , = 2.0 μm, then 05・
t + < t 3 < t 2 0 , 5, and from this, when t2 = 1.1 μm, 0.55 μm < t: + < 0.
The optimum value of the film thickness t of the upper core 6 and t corresponding to the maximum etching method jmax, such as 6 μm, with 3 is determined.

Effects of the Invention As explained above, the present invention is capable of etching an inorganic mask layer into a predetermined shape using a resist mask layer as a mask in the primary etching process, and etching the upper core to a position midway in the thickness direction. Therefore, there is no need to use any special etching method for etching the inorganic mask layer, and the thickness of the inorganic mask layer can be changed from the conventional etching method because the amount of etching of the upper core in the secondary etching process is reduced. Compared to a method using an inorganic mask, the film can be made thinner and the deposition time can be shortened. In addition, by setting the etching depth of the upper core in the primary etching process so that the deposits that adhere to the resist mask layer due to the redeposition phenomenon remain within a range that can be reliably removed later, the effects of the redeposition phenomenon are ensured. can be excluded.

[Brief explanation of the drawing]

Figures 1 (a) to 2) are diagrams showing the steps of an embodiment of the present invention, Figure 2 is a sectional view showing a state in the middle of forming the upper core, and Figure 3 is a diagram showing the structure of a thin-film magnetic head. Cross section, 4th
Figures (A) to (C) are diagrams showing eight steps of the conventional upper core forming method, and Figures (A) to (2) are diagrams showing the steps of another conventional upper core forming method. 2... Lower core, coil, 5... Insulating layer, 6... Upper core, 8... Ion beam, 1 2... Resist mask layer, 9... ・...Inorganic mask layer. Figure 1

Claims (1)

[Scope of Claims] An insulating layer with a coil made of a conductive material interposed therebetween, and an upper core made of a magnetic material whose one end is connected to the lower core are sequentially laminated on a lower core made of a magnetic material,
After that, the method for manufacturing a thin film magnetic head comprises forming the upper core into a desired shape by etching, the method further comprising: forming an inorganic mask layer covering the upper core on the upper core laminated on the insulating layer; , a mask layer forming step of forming a resist mask layer of a predetermined shape on the inorganic mask layer; and irradiating an ion beam with the resist mask layer covered in the thickness direction of the inorganic mask layer and the upper core. a primary etching step of etching up to an intermediate position into a predetermined shape; a resist removal step of removing the resist mask layer on the inorganic mask layer etched into the predetermined shape by the primary etching step; A method of manufacturing a thin film magnetic head, comprising: a secondary etching step of etching the upper core into a predetermined shape by irradiating the upper core with an ion beam again while covered with the inorganic mask layer.