JPS628320A - Production of thin film magnetic head - Google Patents

Abstract

PURPOSE:To form a thin film magnetic head which obviates the disconnection of a head and the increased tendency to crosstalks and has the excellent accuracy of a track width by controlling the incident angle of an ion beam by a taper angle and finally reetching an upper magnetic layer at <=25 deg. incident angle of the ion beam in the case of subjecting the upper magnetic layer to ion milling. CONSTITUTION:A photoresist and the upper magnetic layer 9 are dry-etched by Ar ions at >=25 deg. and <=30 deg. incident angle of the ion bean when the taper angles theta1, theta2 of insulating layers 3, 5, 7 are in a 30-50 deg. range after the photoresist coated on the upper magnetic layer 9 is patterned to a prescribed shape. The upper magnetic layer 9 is thereby etched in an ideal manner without having overetching or imcomplete etching in the tapered parts. Tail part 14 are thoroughly etched if the layer 9 is subjected to the ion milling at <=25 deg. incident angle of the ion beam at which the ion beam is not shadowed by the photoresist after the greater part of said layer is etched at the above-mentioned incident angle of the ion beam. The accuracy of the track width is thus improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a thin film magnetic spatula, and more particularly to a method for manufacturing a thin film magnetic head that has excellent track width accuracy and does not cause any disconnection of the coil. .

[Prior art]

A method of manufacturing a conventional thin film magnetic head will be explained in detail with reference to FIGS. 2 and 6. First, amorphous, Fe-Al-Si alloy (Sendust), Fe-N
a lower magnetic layer (2) made of i-alloy (nosemalloy) or the like;
Furthermore, a first insulating layer (3) made of an inorganic material such as S s O, Si Q 2, A720δ, etc., a coil conductor layer (4) made of Cu or A11, etc., and a first insulating layer on top of that. Similarly, a second insulating layer (5) made of an inorganic material is formed by vapor deposition or centering.

After that, a photoresist (not shown) is thickly coated on the second insulating layer (5), and an ion beam is irradiated onto the photoresist by ion milling or the like so that the etching rate of the photoresist and the insulating layer (5) are the same. angle (hereinafter referred to as the Etching method), the flat second
An insulating layer (5) is formed. Furthermore, the second insulating layer (5)
Coil conductor layer (6) made of Cu or KL on top
, and then SiO or 5i02, A/203
A third insulating layer (7) consisting of evaporation or sp/-?
Form with ivy rings, etc. The third insulating layer (7) is etch-punctured by the same method as that used to flatten the second insulating layer (5). The third insulating layer (7
) on top of the coil conductor layer (41 (61) with 7 Otre cysts (turning not shown)) After that, this photoresist was heat-treated for about 30 minutes at about 1,000 ml.
For example, by ion milling using Ar ions, the insulation layer +3
1, +51, (71 is the predetermined chi-zo angle (θ
1), Chi-ξ etching so that (θ2) 3
At this time, as shown in Figure 3, the angle of the chi/groove (θ, ),
(θ2) can be set to any angle by appropriately selecting the thickness and size of the photoresist. However, if this taper angle is used too rapidly, the upper magnetic layer (9
), the stacking thickness decreases in this part, and the magnetic resistance increases,
Recording and reproducing efficiency decreases. On the other hand, if the slope is too smooth, leakage magnetic flux will increase between the upper magnetic layer (9) and the lower magnetic layer (2), and the recording and reproducing efficiency will similarly decrease. therefore,
It is known that the optimum Qi-7 angle that does not increase magnetic resistance or increase magnetic flux leakage is usually around 60° to 60°.

After performing chiaR etching on the insulating layers (31, f5) and f7+ so as to have an optimal chi-chi angle, SiO,
5i02 or AJ20. The gap layer (8
) is formed by vapor deposition or suctioning. Next, a window for coupling the lower magnetic layer (2) and the upper magnetic layer (9) is etched in the gap layer (8), and then carbon is etched.
Amorphous mainly composed of O or Fe, Fe −
AA'-Si alloy (Sendust) or Fe-Ni
An upper magnetic layer (9) made of an alloy (Thomalloy) is formed by vapor deposition or snoccuttering. After that, a photoresist (not shown) is applied on the upper magnetic layer (9), this resist layer is A-turned into a predetermined shape, and using this as a mask, the upper magnetic layer (9) is exposed to Ar ions, for example. [Problems to be Solved by the Invention] However, there were the following problems when etching the upper magnetic layer (9). This is shown in Figures 4 to 7.
This will be explained in detail using figures.

First of all, when the upper magnetic layer (9) is formed with a thickness of about 10 μm and fC, the tapered portions of the insulating layers f31, +51, +71 are 30° to 60° -T! If a shadow is formed,
The film thickness of the upper magnetic layer (9) at the Q/9 portion is actually thinner than the film thickness at the plane F. Therefore, for the upper magnetic layer (9) formed in this way, for example, the ion beam incident angle ψ (the ion beam incident angle is the angle between the ion beam and the normal direction of the sample) is ψ=σ〒 When ion milling is performed, the plane (θ-0°
) When a predetermined film thickness is completely etched, for example, for a partial mask with a chi A-angle of 50°, the upper magnetic layer (9) has already been removed in about 3 etching times, so there is no remaining sheet. The etching time for the etching process over-etched the 7th part of the taper (part A in Figure 5), and especially in the case of a thick upper magnetic layer of about 10 μm (9), the etching time for the 7th part and the flat surface became very large. Misalignment, coil conductor +4+
, (6) is etched and the head breaks.

Conversely, if the upper magnetic layer (9) is ion milled with the ion beam incident angle ψ=40°,
Because the etching time for the flat part is faster than for the E part, even after the etching of the magnetic layer in the flat part is finished, the magnetic film in the Q part remains, and in the case of a multi-track head, magnetically The drawback was that adjacent devices would short-circuit, worsening crosstalk.

Furthermore, when ion milling the upper magnetic layer (9) using photoresist, there are problems as shown in FIGS. 6 and 7. In other words, when using a photoresist as a mask, the photoresist itself has fluidity, so the photoresist film is thinnest at the part corresponding to the shoulder of the insulating layer (the part indicated by arrow B in Figure 3). Put it away. Therefore, if you try to ensure a sufficient photoresist film thickness in order to form a thick upper magnetic layer (9) in this area, the photoresist layer (9) in the area shown in FIG. It becomes thick.

Figure 6 (a) shows the state at this time viewed from the third direction.
). Shadowing (Sh
The ion beam incident angle (
Here, vShadowing refers to the part of the workpiece that is not hit by the ion beam.

For example, if the sidewall angle of a turned photoresist is approximately 75°, then the ion beam incidence angle at which shadowing occurs is an ion beam incidence angle greater than 25°. ), for example, when ion beam etching is performed at an angle of about 20°, as shown in FIG. 6(a), there is a portion where the etching time is substantially short, that is, a shadow, at the edge αυ of the photoresist (the shaded area in FIG. 6(a)). ing occurs.

When a portion α where the etching time is short is generated at the edge of the photoresist in this way, a part of the upper magnetic layer film sputtered by Ar ions is deposited and reattached to the edge of the photoresist, forming a film a2. do. Therefore, the shape of the upper magnetic layer (9) after peeling off the photoresist is shown in Figure 6 (
As shown in C), an excess film α2 remains at the end. SiO, 5i026 or AJ20. When the protective layer q3 consisting of the above is formed by vapor deposition or sputtering, a crank enters the part shown at E in FIG. Can not.

Conversely, if ion beam etching is performed at an ion beam incident angle of, for example, 30°, which causes shadowing, a region is created where the effective etching time is reduced due to shadowing, as shown in FIG. 7(b). Magnetic pole (
9) has a shape with the base a41 subtracted, and the track width accuracy deteriorates.

The present invention aims to solve the above-mentioned drawbacks, and provides a method for manufacturing a thin film magnetic head that does not cause disconnection of the head, worsening of crosstalk, or occurrence of cranking of the protective layer, and has excellent track width accuracy. There are 't%.

[Means for solving problems]

That is, the present invention sets the chi-to-groove angle of the insulating layer to an optimal angle of 3.
When an upper magnetic layer is formed on the IJI angle formed in the range of 0° to 60° and the upper magnetic layer is ion milled using an inert gas, if the Chi IJI angle is in the range of 30° to 50°, Set the ion beam incident angle to 25° or more and 30° or less,
If the angle is in the range of 50° to 60°,
Ion beam incidence angle of 25° or more and 35° or less -'l'
Etching and finally reduce the ion beam incidence angle to less than 25°! This can be achieved by re-etching.

〔Example〕

That is, as shown in FIG. 1, the thin film magnetic head of the present invention is made of magnetic material such as ferrite or Al2O5°A7203-Tic like the conventional thin film magnetic head.
A lower magnetic layer consisting of an amorphous material mainly composed of CO or F, Fe-AJ-Si alloy (Sendas), Fe-Ni alloy (/'!-Maoi), etc. on a non-magnetic substrate (1) such as layer (2) and further a first insulating layer (3) first
From the coil conductor layer (4), the second insulating layer (5) that has been further planarized, the second coil conductor layer (6), the sixth insulating layer (7) that has been planarized, and the gap layer (8). The taper angle in the insulating layer (5, 5, 7) is
The thickness of the crust and the thickness of the layer that should be turned.
The taper is formed arbitrarily by etching in the range of 30° to 60° depending on the size of the crust. After that, a window (not shown) for coupling the lower magnetic layer (2) and the upper magnetic layer (9) to the gap layer (8) is formed by etching.
Finally, an amorphous material mainly composed of CO or Fe; Fe-Aj-Si alloy (Sendust) or Fe-Ni alloy (Zo-Malloy) is formed as the upper magnetic layer (9) by vapor deposition or sputtering.

Thereafter, a photoresist coated on the upper magnetic layer (9) is patterned into a predetermined shape, and then the insulating layers (3, 5,
When the taper angle (θ1, θ2) in 7) is in the range of 30° to 50°, the ion beam incident angle should be set to 25° or more and 30°.
Below, the photoresist and the upper magnetic layer (9) are etched by 4r ions. By etching at such an ion beam incident angle (25° to 30°), the upper magnetic layer (9) can be ideally etched without oat ζ etching or etching residual film at the chi and groove portions. is as described above using Figures 4 and 5, but to explain it again, Figure 4 shows the relative chi and groove angles (θ) at various ion beam incident angles (ψ). Here, if the film thickness of the flat part of the upper magnetic layer (9) is to, the chi-zoo angle θ is shown.
The film thickness t in is always t<t.

Moreover, since it is known from experimental results that t=tocosθ, n is approximately expressed, the reduction in film thickness at the tapered portion is taken into consideration. Further, here, the etching time on a plane (θ=09) is taken as a reference with an ion beam incident angle ψ=40°. As you can see from this figure, the most desirable ion beam incident angle is 0° (i.e., plane).
If the ion beam incident angle is set so that the etching time is the same when the etching has a taper angle, there will be no auto-etching of the insulating layer, and no residual film will be left on the chi and groove. This means that etching can be done. Therefore, the taper angle θ, including the variation in the etching rate,
It has been found from experimental results that when the angle of incidence is in the range of 30° to 50°, almost ideal etching can be achieved by setting the ion beam incident angle between 25° and 60°.

Also, when the chi-zo angle is in the range of 50° to 60°, the ion beam incidence angle is 25° or more and 65° as shown in Figure 4.
Since the etching time for the plane surface and the sloped surface is almost the same in the region below .degree., ideal etching can be performed without leaving any residual film on the insulating layer or the chisel, similar to the above.

Also, the ion beam incident angle at this time is Chi/J! Corner 3
In the range of 0° to 60°, the angle is larger than 25°, and if you simply mill this angle,
Because of the shadowing caused by the photoresist, the upper magnetic layer (9) is left with a skirt after etching (Fig. 1(d)).Therefore, after etching the main part of the upper magnetic layer (9) at this ion beam incident angle, If ion milling is performed at an ion beam incidence angle of 25° or less so that the ion beam is not shadowed by the photoresist, the base α will be completely etched and the trunk width accuracy will be improved.At this time, the base α4 will be etched completely. Since the etching time is sufficient to last several tens of minutes, the amount of oat ζ-etching of the chi and ξ parts is much smaller than that shown in FIG. 3, and there is no risk of disconnection.

Furthermore, the upper magnetic material, CO or amorphous mainly composed of Fe, Fe = AI-Si alloy (Sendust), Ni-Fe alloy (・Ni-Malloy), was applied at an acceleration voltage of 7
00V, ion current density Q, 60 rrdV'crl
It can be seen from FIG. 8 that when etching is performed with Ar ions in , the etching rate is almost the same with respect to the ion beam incident angle. Therefore, it goes without saying that the above etching method can be applied to these six magnetic materials.

〔Effect of the invention〕

As described above, according to the present invention, the chi 1N angle of the insulating layer is
When an upper magnetic layer is formed on the upper magnetic layer formed in the range of 0° to 60°, and the upper magnetic layer is ion milled using an inert gas, when the upper magnetic layer is in the range of 30° to 50°. When etching the ion beam incidence angle is 25° or more and 60° or less, and when the cheat R angle is in the range of 50° to 60°, the ion beam incidence angle is etched at 25° or more and 35° or less,
Finally, by re-etching the ion beam at an incident angle of 25 degrees or less, it is possible to provide a thin-film magnetic head with excellent track width accuracy without head disconnection or deterioration of crosstalk, which is a very remarkable effect.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the manufacturing method according to the present invention, FIG. 2 is a plan view of a thin film magnetic head with a two-layer coil structure, and FIG.
The figure is a cross-sectional view taken along the line A-x in Figure 2, and Figure 4 shows the relative etching time taken into account the reduction in film thickness at the chi/groove due to the difference in the angle of incidence (ψ) of the various ion beams. Figures 5 and 5 are diagrams explaining the state of overetching, Figures 6 and 7 are cross-sectional views to explain the problems of the conventional process, and Figure 8 is an amorphous film whose main component is Co or Fe. Fe-AJ-Si alloy (Sendust), N
FIG. 3 is a diagram showing the reciprocal etching rate of i-Fe alloy (Somalloy) with respect to the ion incidence angle. Symbols in the figure: 1...Substrate 2...Lower magnetic layer! , 5.7... Insulating layer 4.6... Coil conductor layer 8... Gap layer 9... Upper magnetic layer 10... ...Photoresist 16...
...Protective layer 14 ...... Base to ... ... Thickness t of film etched on plane
......Film thickness T to be etched on the slope...
・・・・・・ Track width Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6
7 Figure 8 Figure 1 Input Mu (de9ree) Procedural Amendment August 73, 1985 1, Indication of Case 1985 Patent Application No. 14! ) 701 No. 2, Name of the invention Method for manufacturing a thin film magnetic head 3, Person making the amendment Relationship to the case: Name of the patent applicant (520) Fuji Photo Film Co., Ltd. Kasumigaseki Building Post Office P.O. Box @ 49 No. 6, By amendment Increased number of inventions 0 7, "Detailed Description of the Invention" column 8 of the specification to be amended, and content of the amendment "Detailed Description of the Invention" column are amended as follows. 1) FjI4 specification, page 7, line 16, r (Figure J6 (a
) Delete the shaded part). 2) From page fX7, line 17 to @line 20 of the specification, “
03) On page 9, line 15 of the specification, "Fig. 1" is amended to "Fig. 6." 4) Page 12, line 17 of the specification, “(Figure 1 (d))
J is corrected to ``(Figure 1 (b) month.) 5) In the 5th line of Section 1fi of the specification, ``Figure 6'' is changed to ``Figure 1 (b) month.''
Correct it to "Fig."

Claims (2)

[Claims] (1) It has a laminated structure including a lower magnetic layer, an insulating layer, a coil conductor layer, a gap layer, and an upper magnetic layer, and the upper magnetic layer is placed on the insulating layer with a taper angle in the range of 30° to 60°. In the method for manufacturing a thin film magnetic head formed by ion milling from above after depositing the ion beam, when the taper angle is approximately 50° or less, the ion beam incidence angle is set to 25° or more and 30° or less, and the taper angle is approximately 50° or less. If the ion beam incidence angle is approximately 50° or more, etching is performed at an ion beam incidence angle of 25° or more and 35° or less, and then the ion beam incidence angle is etched at 25° or more.
A method for manufacturing a thin film magnetic head characterized by re-etching at a temperature of less than 100°C. (2) The upper magnetic layer is amorphous mainly composed of Co or Fe, or Fe-Al-Si alloy, Fe-Ni.
A method of manufacturing a thin film magnetic head according to claim 1, wherein the thin film magnetic head is made of an alloy.