JPH0822610A - Production of thin-film magnetic head - Google Patents

Abstract

PURPOSE:To form a magneto-resistance(MR) type thin-film magnetic head dealing with a higher recording density by forming electrode patterns on a photosensitive material by photolithography and diagonally irradiating this material with ions, thereby ion trimming the material. CONSTITUTION:An MR element 2 is formed by photolithography and etching on a substrate 1 consisting of a nonmagnetic material. An electrode film 3 consisting of a conductive material is then formed on this element 2 and the electrode patterns are formed by photolithography on the resist 4 of the photosensitive material. The resist is ion trimmed by diagonal irradiation with the ions to form electrodes 10. The ion trimming is executed at the spacings narrower than the spacings between the electrode patterns by utilizing the shadows of the resist 4, by which the inter-electrode spacings are narrowed and the track width is narrowed regardless of the accuracy of a photomask. Consequently, the magneto-resistance effect type thin-film magnetic head dealing with the higher recording density is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a thin film magnetic head suitable for high recording density.

[0002]

2. Description of the Related Art FIG. 3 is a diagram showing a manufacturing process of electrodes of a conventional magnetoresistive thin film head. First, a magnetoresistive effect element (hereinafter referred to as MR element) 2 is formed on a substrate 1. The formation of the MR element 2 is generally achieved by a photolithography technique and an etching technique. After that, an electrode film 3 is formed on the MR element 2, and a resist 4 which is a photosensitive material is coated on the electrode film 3. Next, FIG. 3- (a)
As shown in FIG. 3, a resist 4 is formed into an electrode pattern by using a photolithography technique, and then ion milling is performed. Generally, the electrode film is patterned according to the shape of the electrode pattern, so that ions are poured from the direction perpendicular to the substrate.

When the MR element 2 appears after the electrode film 3 is removed by ion milling, the ion milling ends and the state shown in FIG. 3- (b) is obtained.

Finally, the resist 4 is removed and the process shown in FIG.
As shown in (c), the electrode film 3 is formed in an electrode pattern on the MR element 2.

[0005]

In the current magnetic recording field in which the recording density is increasing, it is an important subject to reduce the track width of a recording medium on which magnetic information is recorded. Along with this, it is necessary to narrow the track on the magnetic head side that reads information from the magnetic head. In a magnetoresistive thin film head using an MR element, M
The track width for information reading is regulated by the distance between the pair of electrodes arranged at both ends of the R element.

On the other hand, the formation of the electrode for controlling the track width is
Ion milling is performed using the electrode pattern of the resist. The electrode pattern made of the resist must remain in its shape until the electrode film is ion milled and disappears, and the resist thickness is at least 1
At least μm is necessary. However, the thicker the resist, the more difficult it becomes to finely pattern the resist by photolithography. Generally 1μ thick
It is difficult to form a resist of m or more on the electrode pattern with an interval of 1 μm or less, and with the conventional electrode forming method in which the electrodes are formed according to the electrode pattern, it is difficult to set the electrode interval to be the track width to 1 μm or less.

Further, since the electrodes are formed according to the electrode patterns, the lot variations that occur when the electrode patterns are formed are the same as the electrode dimensions. For example, the processing accuracy when forming the electrode pattern is 1 ± 0.1μ
If m, the dimensional accuracy of the electrode is naturally 1 ± 0.1 μm. The processing accuracy of the electrode pattern is greatly affected by the accuracy of the exposure apparatus used in photolithography, and an expensive exposure apparatus is required to increase the processing accuracy.

[0008]

According to the present invention, in order to solve the above-mentioned problems, the electrode patterns are preliminarily widened, and ions are obliquely applied to the substrate in the ion milling process for forming the electrodes. It was made to enter from above, and the part which becomes the shadow of the electrode pattern formed of the resist was prevented from being ion milled.

[0009]

By tilting the incidence of ions, it is possible to use the shadow of the resist to perform ion milling at a distance narrower than the distance between the electrode patterns, and as a result, the distance between the electrodes can be reduced. . Therefore, the track width regulated by the distance between the electrodes can be narrowed regardless of the processing accuracy by photolithography, and the magnetoresistive thin film head compatible with high recording density can be manufactured.

Further, according to the present invention, the distance between the electrodes to be originally manufactured can be made smaller than the distance between the electrode patterns formed by photolithography, so that the dimensional accuracy of the photomask and the processing accuracy in the photolithography process are also required. Not. This is because the variation in processing during electrode pattern formation can be reduced during electrode formation as well as the electrode spacing. Therefore, the work can be done easily without paying much attention to the photolithography process, and the exposure apparatus used in the photolithography process can be inexpensive and have low processing accuracy. Therefore, the cost can be reduced.

[0011]

1 is a sectional view of an electrode of a magnetoresistive effect thin film head of the present invention, and FIG. 2 is a diagram showing a manufacturing process of an electrode of a magnetoresistive effect thin film head of the present invention. First, the MR element 2 is formed on the substrate 1 made of a non-magnetic material by using the photolithography technique and the etching technique. Then M
An electrode film 3 which is a conductive material is formed on the R element 2, and a resist 4 which is a photosensitive material is coated on the electrode film 3.
The state shown in FIG.

Next, as shown in FIG. 2- (b), a resist 4 is formed into an electrode pattern by using a photolithography technique.

After that, ion milling is performed as shown in FIG. At this time, by making ions obliquely incident on the surface of the electrode film 3, it is possible to narrow the ion-milled portion of the electrode film 3 by utilizing the shadow of the electrode pattern formed by the resist 4.

Ion milling is terminated when the electrode film 3 is ion-milled and disappears and the underlying MR element 2 appears. As a result, the state shown in FIG.

After that, the resist 4 is removed by using a stripping solution or the like to finally form the electrodes 10 having a narrow interval as shown in FIG.

The relationship between the ion incident angle and the electrode spacing was actually examined by experiments. FIG. 4 is a schematic view of the sample used in the experiment of the present invention. As an experimental method, first, an electrode film 3 is formed on a substrate 1 made of glass, a resist 4 is coated on the substrate 1 to a film thickness t, and the resist 4 is formed by photolithography into electrodes having an interval L2. Form in a pattern. After that, ion milling is performed by changing the ion incident angle θ, and the electrode spacing L1 of the electrodes actually formed.
I checked the difference. The electrode film 3 was formed by sputtering Cr with a thickness of 0.2 μm. As the resist 4, AZ4330 manufactured by Hoechst Co. was used, and the resist was coated with a resist thickness t = 3 μm by spin coating. In addition, the pattern interval L of the electrode pattern formed by photolithography
2 was 6 μm and the experiment was performed. Patterning the resist 4 having a film thickness of 3 μm into an electrode pattern having an interval of 6 μm by photolithography is a general level and not a difficult technique.

Since the electrode film 3 is much thinner than the resist 4, the relational expression (1) holds between the ion incident angle θ and the electrode interval L1. Since 0 ≦ tan θ ≦ ∞, theoretically, the electrode interval L1 can be 1 μm or less regardless of the pattern interval L2 and the resist thickness t. L1 = L2-t / tan θ (1)

FIG. 5 shows the results of examination of the relationship between the ion incident angle θ and the electrode interval L1 by experiments. The square mark is the experimental result, and the alternate long and short dash line is the theoretical value according to equation (1).
From this result, it is understood that the electrode interval L1 becomes narrower as the incident angle θ is made smaller, that is, the ions are obliquely incident on the electrode film surface. Further, the result of this experiment shows a value very close to the theoretical value, and it was confirmed that the electrode interval L1 can be estimated by using the formula (1). According to the equation (1), in this experiment, the ion incident angle θ
Is in the range of 27 ° to 31 °, the electrode interval L1 can be narrowed to 0.1 to 1 μm. In the present experiment, the effect of controlling the ion incident angle θ on the ion energy state in the vicinity of the substrate, which is seen in a general ion implantation method, was not particularly observed. Further, as can be seen from the fact that the present experimental sample almost agrees with the theoretical value, the dimensional variation among lots is very small according to the present manufacturing method. This is because variations in the electrode pattern formed by photolithography are also reduced during electrode formation according to the present manufacturing method.

This manufacturing method is not only effective for narrowing the gap between the electrodes for controlling the track width of the MR element of the magnetoresistive thin film head, but can also be used for the step of forming the gap of the planar magnetic head. .

FIG. 6 is a sectional view of a main part of a flat type magnetic head. A lower magnetic pole 5 made of a magnetic material is arranged on the non-magnetic substrate 1 so as to intersect with the coil 7, and a non-magnetic and electrically insulating material is placed between the coil 7 and the lower magnetic pole 5. Is electrically and magnetically shielded by an insulating layer 6 made of.
The lower magnetic pole 5 is in contact with the upper magnetic pole 8 and constitutes a magnetic circuit. A part of the upper magnetic pole 8 has a notch, and the notch is exposed on the surface of the head. This cutout portion is called a gap, and a magnetic signal can be recorded on the recording medium by the leakage magnetic flux leaking from here when a current is passed through the coil 7. Also, in order to protect the head from external impact, a hard protective layer 9 is provided around the gap.
Covered with.

In order to record a magnetic signal on a recording medium with a high recording density, it is important to make this gap as narrow as possible. Therefore, the gap can be narrowed by using the manufacturing method of the present invention as in the case of forming the electrodes of the magnetoresistive thin film head.

[0022]

According to the present invention, in the ion milling performed in the electrode forming step, by making the incidence of ions oblique, it is possible to utilize the shadow of the resist to perform the ion milling at a distance narrower than the distance between the electrode patterns. Becomes possible,
As a result, the interval between the electrodes can be narrowed in the range of 0.1 to 1 μm. Therefore, the track width regulated by the electrode interval can be set to 0.1 to 1 μm, and the magnetoresistive effect thin film head corresponding to high recording density can be manufactured.

Further, according to the present invention, since the distance between the electrodes to be originally manufactured can be made smaller than the distance between the electrode patterns formed by photolithography, the dimensional accuracy of the photomask and the processing accuracy in the photolithography process are also required so much. Not. This is because the variation in processing during electrode pattern formation can be reduced during electrode formation as well as the electrode spacing. Therefore, the work can be done easily without paying much attention to the photolithography process, and the exposure apparatus used in the photolithography process can be inexpensive and have low processing accuracy. Therefore, the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of electrodes of a magnetoresistive thin film head according to the present invention.

FIG. 2 is a manufacturing process diagram of electrodes of the magnetoresistive thin film head of the present invention.

FIG. 3 is a manufacturing process diagram of electrodes of a conventional magnetoresistive thin film head.

FIG. 4 is a schematic diagram of a sample used in an experiment of the present invention.

FIG. 5 is a diagram showing a relationship between an ion incident angle θ and an electrode interval L1 according to an experiment of the present invention.

FIG. 6 is a cross-sectional view of a main part of a planar magnetic head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 MR element 3 Electrode film 4 Resist 5 Lower magnetic pole 6 Insulating layer 7 Coil 8 Upper magnetic pole 9 Protective layer 10 Electrode

Claims (2)

[Claims] 1. A method of manufacturing a thin-film magnetic head comprising a magnetoresistive effect element and a pair of electrodes formed on both ends of the magnetoresistive effect element with a predetermined gap therebetween. A step of coating a photosensitive material on an electrode film which is a material for forming the pair of electrodes, and forming a pair of electrode patterns formed of a resist having a predetermined interval by the photosensitive material by a photolithography technique; And then forming the pair of electrodes having an interval that is narrower than the interval between the electrode patterns by ion milling in which ions are incident at an oblique angle so as to form a shadow of the electrode pattern. A method of manufacturing a thin film magnetic head, comprising: 2. The distance between the pair of electrodes is L1, and the L1 is
Is in a range of 0.1 μm ≦ L1 ≦ 1 μm.