JPS5996525A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To prevent the damage on the surface of a magnetic substrate on account of overetching by laminating respectively a protective layer of Ti, a conductive layer of Cu, etc. and a mask layer of Ti on a magnetic substrate. CONSTITUTION:A Ti film 9 to serve as a protective layer is deposited by evaporation at about 1,000-1,500Angstrom on a magnetic substrate 1 and further a Cu film 7 to serve as a lead is deposited by evaporation at about 2mu thereon; further, a Ti film 8 to serve as a mask is deposited by evaporation at about 1,000-1,500Angstrom thereon. A photoresist pattern is formed on a wafer and the film 8 is worked by a dry etching method. The film 7 is sputter-etched with the film 8 as a mask. Overetching is performed to etch off thoroughly the film 7 in this stage but the rate of the sputter etching for Ti is about 1/10 of the rate for Cu, therefore even if the overetching is performed, the surface of the substrate 1 is protected by the film 9 without removing the film 9 and the surface of said substrate is entirely smooth.

Description

[Detailed description of the invention] Kuwaza i! 14 Fields> The present invention relates to magnetic disk devices, magnetic disk devices (tape devices i; i1
The present invention relates to a thin film magnetic C head capable of performing magnetic recording such as the following.

<Conventional technology> FIG. 1 shows the structure of a conventional thin film magnetic head.

The same figure (a) is the id plan view, the same figure (b) is the A- of the same figure (a).
FIG. 3 is a side sectional view taken along line A'. As shown in the figure, a conductive layer 2 of Cu, An, etc. is formed on a magnetic substrate 1. The conductor layer 2f:
Insulating layer such as Ksio2,5iD3N43. A magnetic layer 4 made of a Ni-Fe alloy or a Fe-AeHsi gold alloy is laminated on the insulating layer 3. The magnetic substrate 1 forms a lower core, and the magnetic layer 4 forms a negative core. As shown in the figure, the upper core and the lower core are magnetically coupled at a back core section 5 at the rear of the head, and are opposed to each other at a head gap section 6 at the tip of the head via an insulating layer 3. are doing. In the conventional thin-film magnetic head described above, the surface smoothness of the 12th core (magnetic substrate 1) in the back core part 5 and the head gap part 6 is very important for the reproduction (or recording) characteristics of the head. That's a problem.

Below, we will explain the influence on the surface and 1f smoothness of the side core (magnetic plate 1: J, U plate 1).

The thin film magnetic head shown in FIG. 1 is used as a recording head for -1:, and its operating principle is the same electromagnetic induction phenomenon as that of the conventional bulk head. To explain the recording operation,
! A magnetomotive force is generated in the magnetic core consisting of the upper core and the lower core by energizing the conductor layer 2, which is 1-1-''. Magnetic flux flows in the magnetic core due to this 11μ magnetic force, and the headgear 1 .Magnetic flux leaks at the knob portion 6, and this leaked magnetic flux becomes a recording magnetic field.In order to improve the head efficiency (recording magnetic field per medium recording current) for performing the above recording operation, magnetic It is necessary to reduce the amount of magnetic flux leakage within the core as much as possible to effectively guide the magnetic flux to the hend gap portion 6. To do this, it is necessary to minimize the surface of the lower core magnetic material near the hend gap portion 6. It is necessary to smooth it. If the surface of the lower core magnetic material near the head gap part 6-9 is rough or there is a process-affected layer on the surface, smooth it. Since the amount of leakage of magnetic flux increases in the hend gap portion 6, the magnetic flux may not effectively reach the hend gap portion 6, or the effective gap length of the head increases, resulting in a decrease in hend efficiency. In addition to thinning, the important factor for improving head efficiency is to minimize the magnetic resistance (reflectance) of the magnetic core and to minimize the energy loss of the magnetic flux flowing through the magnetic core.
It is. Is the back core likely to cause reluctance due to the internal shape of each part of the magnetic core? 31! It is 5. In this part, the lower core (sulfur column plate 1) and -1] side core (magnetic layer 4) are magnetically coupled simply by contact, so the surface of the + side core is in this part. If the head is in a rough state or if there is a damaged layer on the surface, the vacancy increases significantly and the head efficiency decreases as a result.

FIG. 2 is a side cross-sectional view of a thin film magnetic head in which irregularities and a damaged layer are formed on the magnetic substrate 1 of the back core portion 5 and the head gear knob portion 6.

Now, it is said that the sputter etching method is one of the most effective methods for finely machining the leads of thin-film magnetic heads. The formation process of forming a lead pattern using the IR and sub-interetching method will be described. Assuming that the monthly production of 1 saw is 1, it is assumed that the reed pattern is formed using 1 inch. FIG. 3 is a process explanatory diagram of a forming process for forming a lead pattern using the conventional mega-vine etching method.

Magnetic substrate 1" Second, lead material Cu and mask A.
*1゛I of 1 h is sequentially applied by vacuum evaporation method, spack method, etc.;
, H, Cu 11 stool 7 and Ti film 8.

In the step T i of FIG. 3(b), a flat sub-registration 1 having a predetermined pattern shape is formed on the film 8-L.
- Mask the film and etch the Ti film 8 into a predetermined pattern shape by dry etching or the like.

In step 4 of FIG. 3(C), the Cu film 7 is sputter-etched using T i Il #j 8 as a mask. At this time, the sputter etching of Cu1l+i7 is completed completely uniformly within the wafer surface, while the process is actually -1, (Since it is 1, it is usually etched for a certain amount of extra time and over-etched), -
Finish etching the entire bar surface 1. The problem here is to avoid over-etching the surface of the magnetic substrate 1 or the sub-layers.
This is the point that is sputter-etched for a time equal to 1.

For example, when polycrystalline ferrite is used as the substrate material of the magnetic substrate 1, the shape of the crystalline r-field clearly appears on the surface after about 20 minutes of overetching.

Does this mean that in the magnetic substrate 1 using polycrystalline ferrite, the spankling yield naturally changes due to the presence of crystal viscosity with different crystal axes? Unlike IJ, the difference in etching speed of the crystal viscosity causes a difference in level during settlement, and as a result, the surface of plate 1 becomes rough. Therefore, 1) II. /There is no way to avoid this kind of deterioration in head efficiency.

<Purpose> The present invention has been made in order to eliminate the drawbacks of the prior art described below, and its primary purpose is to solve the problem of surface damage to magnetic plates due to overetching. .

<Embodiment> Hereinafter, an embodiment of the thin film magnetic head 1 according to the present invention will be described in detail with reference to the drawings.1 and 4 show an embodiment of the 'A'7 film magnetic head according to the present invention. g of the lead of
Srs will explain the details of ■ culm. FIG. 4 is a process explanatory diagram of a forming process for forming a lead pattern by sputter etching.

It is assumed that Cu is used as the material of the lead material, and Ti is used as the mask 4J I+ for forming the lead pattern.

In Fig. 4(a), on the magnetic substrate 1 consisting of a light film, a protective layer of November 9 is evaporated at a temperature of 1000 to 1500A (spackling may also be used), and a Cu film is further formed as a lead. 7 is evaporated to about 2 μm, and a 'I''i film 8 to serve as a mask is deposited to a thickness of 1,000 to 1.5 μm.
500 A culm vapor deposition (spack may be used).

In Fig. 4 (1), a photoresin pattern 1 such as 500 is formed on a wafer, and Ti1l'jj8 is 1.'
Processed using the Laienotink method.

In step T + 11% 8 of FIG. 4(c), Nupac etching is performed on the (-ull board 7) as a mask. At this time, over-etching is performed to completely etch off the Cu film 7, but sputter etching of Ti a degree 1d, Cu scattering y
-f- The Ti film 9 will not be removed even if the culm over-etching is performed for 20 minutes because the etching speed is about 0. Since the surface of the magnetic substrate 1 is protected by the Ti film 9, the magnetic substrate The surface of J is completely smooth.

2.The T1 film 9 also works as an adhesion layer that increases the adhesion strength between the Cu film 7 and the magnetic substrate 1, so even if the line width of the Cu film 7 is narrow, the adhesion between the magnetic film 171 and the magnetic substrate 1 is maintained. The force is good and the ability to increase the density of the lead is what can be done.

Although the process of forming leads on the magnetic substrate 1 has been described above, other structures 2 (insulating layer 3, magnetic Layer 4) may have the same structure as the conventional thin film magnetic spatula 1-'.

<Effects> According to the present invention, a thin film magnetic head with high head efficiency can be obtained because the structure is such that damage to the surface of the magnetic substrate due to overetching during lead pattern formation can be prevented to <-11.

[Brief explanation of drawings]

Figure 1 shows the structure of a conventional thin-film magnetic head.
2 is a side sectional view of a conventional thin-film magnetic spatula 1-, and FIG. 3 is a diagram showing a step in the process of forming a reed baggage 1 using the conventional Nupasoquetting method. 1 and 4 are explanatory diagrams of the formed lower culm forming a thin film magnetic/RAD's Svatuta etching'/LVC pattern according to the present invention. In the figure, J: Magnetic substrate 2: Conductor Fi 3: Insulating layer 4: Magnetic layer 5: Back cover y) 4+S 6 m spatula 1゛gage/tube portion 7: CIJ film 8.9: i"1 film

Claims (1)

[Claims] 1. A layer 1 (titanium) which functions as a protective layer on the magnetic board, a layer 4 (layer 4) of Cu (copper) etc. on the Ti (titanium) layer, and a layer 4 (layer 4) of conductor such as Cu (copper) on the Ti (titanium) layer. 1. A thin film magnetic head characterized by having a structure in which a Ti (titanium) layer is provided, each layer functioning as an etching mask for Nupatta etching.