JPH0432011A - Production of thin-film magnetic head - Google Patents

Abstract

PURPOSE:To obtain the taper of an insulating layer consisting of SiO2 at a good yield by etching the insulating layer formed by using RIE. CONSTITUTION:The insulating layer 13 is subjected to the etching by using the RIE. An undercut is suppressed low and the insulating layer 13 of the SiO2 is etched if the RIE is used in such a manner. An etching gas of a fluorine system and the SiO2 come into reaction at this time and are discharged in the form of gaseous SiF4 and, therefore, the resticking of the etched insulating layer to a substrate does not arise. Since the RIE is reactive, the resist 14 formed on the insulating layer 13 is more hardly etched than the insulating layer 13 of the SiO2 conversely from ion milling and the absolute quantity of the resist 14 to be etched is decreased. The taper of the insulating layer 13 consisting of the SiO2 is obtd. at the good yield in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a thin film magnetic head, and more specifically to a method for manufacturing a thin film magnetic head having an insulating layer made of Sing for maintaining electrical insulation of a conductive coil. Regarding the manufacturing method.

[Misconceptions] In conventional thin film magnetic heads, baked photoresists have often been used as the insulating layer of the conductive coil.

However, recently, with the increase in recording density, CO-based amorphous materials with excellent soft magnetic properties have been used as the magnetic poles of thin-film magnetic heads. Since the temperature is lower than the above-described firing temperature of photoresist (200° C. or higher), insulating materials other than photoresist are increasingly being used. Among these, SiO□, which can be formed by sputtering, is often used as an insulating material for the conductive coil.

Conventionally, when forming an insulating layer made of 5102, the taber is formed by etching the substrate from an oblique direction at the same angle as the taber angle using ion milling. For example, if the target Taber angle is 35° with respect to the substrate surface, the incident angle of the ion beam is also 35°.
Set to 5° and perform ion milling. As a result, the portion 3102 that was masked by the resist remains intact, while the unmasked portion of SiO□ is etched in accordance with the incident angle of the ion beam, making it possible to form a taber at the target angle. .

Problem 8: However, when etching the insulating layer by ion milling as described above, for example, a
It was necessary to apply about 6 um of resist to 102. In other words, the etching rate of the resist in ion milling is 2 to 3 higher than 1 for SiO□.
Since the resist is etched faster than 3102, it was necessary to form the resist about three times thicker than 5102 in order to prevent the resist from being removed by etching. At this time, a large amount of resist and Sing removed by ion milling re-attached to the substrate, causing a decrease in the yield in the tapering formation of the 5102 insulating layer.

The present invention was made in view of the above-mentioned problems, and
It is an object of the present invention to provide a method for manufacturing a thin film magnetic head that can form a taber of an insulating layer made of O□ with a high yield.

Understand Section 11, No. 1 To achieve the above-mentioned object, a method for manufacturing a thin film magnetic head according to the present invention includes an insulating layer made of SiO□ for maintaining electrical insulation of a conductive coil. The method for manufacturing a thin film magnetic head is characterized in that the insulating layer is etched using RIE.

Further, in the above-described method, after forming a resist pattern on the insulating layer, etching is performed using RIE from an oblique direction to the substrate, and further, a taber is formed on the edge of the insulating layer. It is characterized by forming an applied resist pattern.

Furthermore, the above method is characterized in that etching is performed from an oblique direction at an angle smaller than the target taper angle of the end of the insulating layer, and that a mixed gas of CF4 and CHF3 is used as the etching gas in the RIH. It is a feature.

According to the method for manufacturing a thin film magnetic head described above, the R
When IE is used, the SiO□ insulating layer is etched with a small undercut. At this time, the fluorine-based etching gas and Sing react, and 5IF
Since the etched insulating layer is exhausted as a gas of No. 4, the etched insulating layer does not re-adhere to the substrate. In addition, the RIE
Since is reactive, contrary to ion milling, the resist formed on the insulating layer is less likely to be etched than the insulating layer of SiO□, and the absolute amount of resist to be etched is smaller. Therefore, the amount of resist redeposited onto the substrate is reduced, and it is possible to use a thin resist film.

Further, when etching is performed using RIE from an oblique direction to the substrate after forming a resist pattern on the insulating layer, since the RIE has a large anisotropy, the edges of the insulating layer are etched. A taber with an angle close to the target is formed.

Furthermore, when forming a resist pattern with tapered ends on an insulating layer, etching by RIE from an oblique direction to the substrate will result in the resist pattern becoming thinner even if it becomes thinner due to etching. does not change, so the insulating layer in a certain region is etched. Therefore, a straight taber is formed.

In addition, when etching is performed from an oblique direction at an angle smaller than the target taper angle of the end of the insulating layer in consideration of undercuts, it is necessary to accurately form a taper at the target angle at the end of the insulating layer. becomes.

Furthermore, when a mixed gas of CF and CHF3 is used as an etching gas in RIE, a protective film is formed on the tapered surface during etching, suppressing undercuts, and eliminating undercuts at the ends of the insulating layer. This results in the formation of a good taper.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing a thin film magnetic head according to the present invention will be explained with reference to the drawings.

FIG. 1 is a cross-sectional view schematically showing an example of an etching step in a method for manufacturing a thin-film magnetic head according to the present invention. 1st
In the figure, 11 is a substrate made of, for example, Sl, and on this 31 substrate 11, a film of Cu 12 of about 0.3 μm is formed. Here, the reason why Cu12 is formed is that if RIE etching is performed, the substrate 11 of 31 will also be etched, and there is a possibility of erroneously observing the shape change due to etching.For this reason, the etching of 5i02 is C not etched in RIE for endpoint use
A film u12 is formed on the substrate 11.

Approximately 2 μm of 5i was deposited on Cu12 by sputtering.
(An insulating layer 13 made of (h) is laminated, and a resist 14 with a thickness of about 0.05 μm is patterned on top of the insulating layer 13 with its edges substantially perpendicular.

The substrate 11 is arranged so that the surface of the laminate thus formed is parallel to the electrode, that is, the irradiation direction of the etching gas is approximately 90 degrees to the surface of the substrate 11, and the CF,
Etching was performed by RIE using as an etching gas.

As a result, the insulating layer 13, which had been etched with a large undercut in conventional ion milling, could be etched with a small undercut, as shown in FIG.

The optimum etching conditions at this time are: input power of 750 W, gas pressure of 0.4 Torr, and gas flow rate of 100 SCCU.
The etching rate of the insulating layer 13 of S10□ is set to resist 1.
4) was obtained. Also 5
The etching rate of the insulating layer 13 made of 102 was 720 etching per minute, and the temperature of the substrate 11 was about 160°C.

FIG. 3 is a sectional view schematically showing another example of the etching step of the method for manufacturing a thin film magnetic head according to the present invention. In this embodiment, in order to form a taper at the end of the insulating layer 13 shown in FIG. 1, CF was applied from an oblique direction to the substrate 11 under the optimum conditions described in 2 above.

Then, etching was performed by RIE. Note that the ends of the resist 14 formed on the insulating layer 13 are not tapered, and the target taper angle of the resist 14 is 35 degrees, and the inclination of the substrate 11 with respect to the electrode is 25 degrees.
The angle was changed to 30°, 35°, and 40°.

FIG. 4 shows the state of the insulating layer 13 and resist 14 after etching. As is clear from FIG. 4, the resist 14
5i02 because the corners of the 5i02 were etched early.
The etched region of the insulating layer 13 was expanded, and a slightly tapered shape was formed. However, it was confirmed that the required taper could be formed by etching the substrate 11 from an oblique direction using RIE, which is anisotropic etching. In particular, when the inclination of the substrate 11 was set to 25 degrees as shown in Table 1, it was possible to form a taper at an angle close to the target with only a slight undercut being observed.

Table 1 and FIG. 5 are cross-sectional views schematically showing still another example of the etching process of the method for manufacturing a thin film magnetic head according to the present invention. As shown in FIG. 5, in this embodiment, the substrate 1 is attached to the end of the resist 14 formed on the insulating layer 13.
A taper having the same angle as the inclination of 1 was provided, and etching was performed by RIE using CF from an oblique direction to the substrate 11 under the above-mentioned optimum conditions. Here, the taper of the resist 14 can be adjusted by adjusting the exposure time, illuminance, and development time for a mask (not shown) placed on the resist 14, and by adjusting the heat treatment conditions after development. , formed at a predetermined angle.

FIG. 6 shows the state of the insulating layer 13 and resist 14 after etching. As shown in FIG. 6, if the resist 14 is tapered, even if the resist 14 is
Even if the insulating layer 13 becomes thinner, its shape does not change, so a certain area can be etched, and a linear taper without any hemline can be formed in the insulating layer 13. Also, the undercut at this time was extremely small.

As another example, etching was carried out by RIE under the same conditions as in FIG. 5, using a mixed gas of CF and CHF3 in a ratio of 4:1 as the etching gas. Note that at this time, the end portion of the resist 14 was tapered at the same angle as the inclination of the substrate 11. Also target resist 14
The taper angle was 35°, and the inclination of the substrate 11 with respect to the electrode was changed to 25°, 30', 35°, and 40°.

As a result, a protective film was formed on the tapered surface during etching, suppressing undercuts, and it was possible to form a good taper with almost no undercuts observed at the end of the insulating layer 12. In addition, as shown in Table 2, the base ml
When the slope of l was set to 30", it was possible to accurately form a taper at the target angle in the insulating layer 12. From these facts, it was possible to perform etching from an oblique direction at an angle smaller than the target taper angle. was confirmed to be effective in forming a taper of a target angle at the end of the insulating layer 13.

(See margins below) Table 2 Finally, an actual thin 11i magnetic head was manufactured using the method described above, and the state of re-adhesion of the 5iOz insulating layer 13 and the resist 14 during the manufacturing process was investigated.

As a result, the etched insulating layer I3 5102 is
No redeposition was observed because it reacted with the fluorine-based etching gas and became a 5IF4 gas and was exhausted. Furthermore, in etching by RIH, resist 14 was 5
Since it is less likely to be etched than 102 and the amount of resist 14 to be etched is smaller, the amount of attached resist 14 is also significantly reduced.

Furthermore, when the insulating layer 13 was tapered by conventional ion milling, the yield was only 91%, but by using RIE, the yield increased to over 99%.
A good result was obtained in that there were almost no defects in the step of forming the taper of the insulating layer 13.

As is clear from the above explanation, according to the method for manufacturing a thin film magnetic head according to the present invention, a thin film magnetic head equipped with an insulating layer made of 5102 for maintaining electrical insulation of a conductive coil is produced. In the manufacturing method, since the insulating layer is etched using RIE, the insulating layer made of 5102 can be etched with undercuts kept small. At this time, fluorine-based etching gas and 5 inch
2 reacts with SiO 2 and is exhausted as a gas, and the absolute amount of resist to be etched is small. Therefore, the redeposition of etched 5102 and resist to the substrate can be greatly reduced, and therefore SiO □ A tapered insulating layer consisting of the following can be manufactured with good yield.

In addition, in the above-described method, when etching is performed using RIE from an oblique direction to the substrate after forming a resist film on the insulating layer, the undercut at the end of the insulating layer is small and the etching target is not exceeded. Tapers with close angles can be formed.

Furthermore, in the above-described method, when forming a resist pattern with tapered ends on the insulating layer, when the substrate is irradiated with etching gas by RIE from an oblique direction, the insulating layer is etched in a certain region. The layers can be etched. Therefore, a linear taper can be formed, and undercuts can also be kept small.

In addition, in the above method, when etching is performed from an oblique direction at an angle smaller than the target taper angle of the end of the insulating layer, can be formed accurately.

Furthermore, in the above method, when a mixed gas of CF4 and CHF3 is used as the etching gas in RIE, a protective film is formed on the tapered surface during etching to suppress undercuts, and the end portions of the insulating layer are A good taper without undercut can be formed.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view schematically showing an example of the etching process of the method for manufacturing a thin film magnetic head according to the present invention, and FIG. FIG. 3 is a cross-sectional view schematically showing another example of the etching process of the method for manufacturing a thin 11 mm head according to the present invention, and FIG. 4 is a cross-sectional view after the etching process shown in FIG. FIG. 5 is a cross-sectional view schematically showing the state of the tapered portion of the resist and insulating layer; FIG. FIG. 6 is a cross-sectional view schematically showing the tapered portion of the resist and insulating layer after the etching process shown in FIG. 11...Substrate 13...Insulating layer 14...Resist patent Applicant: Sumitomo Metal Industries Co., Ltd. Representative/patent attorney Ryu Bennai Figure 1jJJjjjjj Figure 2Figure 3 〒Terra drunkenness 11

Claims (5)

[Claims] (1) SiO_2 to maintain electrical insulation of conductive coil
1. A method of manufacturing a thin-film magnetic head comprising an insulating layer comprising etching the insulating layer using RIE. (2) The method of manufacturing a thin film magnetic head according to claim 1, wherein after forming a resist pattern on the insulating layer, etching is performed using RIE from an oblique direction on the substrate. (3) The method of manufacturing a thin film magnetic head according to claim 2, wherein a resist pattern having tapered ends is formed on the insulating layer. (4) Claims 1 and 2 in which the etching is performed from an oblique direction at an angle smaller than the target taper angle of the end of the insulating layer.
Or a method for manufacturing a thin film magnetic head according to claim 3. (5) Claims 1 and 2, in which a mixed gas of CF_4 and CHF_3 is used as an etching gas in RIE;
A method of manufacturing a thin film magnetic head according to claim 3 or 4.