JPH04251915A - Formation of element pattern and plated frame using the pattern - Google Patents

Abstract

PURPOSE:To form a desired element pattern and an inverted pattern by photoli thography and form a pattern which has high cross-section aspect ratio and a plating mask pattern. CONSTITUTION:Novolak resin positive resist, etc., is formed as a first pattern, a second synthetic rubber negative resist, etc., which do not resolve with developer to be used is filled between the first patterns, and the second pattern is left as an inversion pattern by photolithography. The inversion pattern can be also used as a mask for plating process. The high aspect ratio pattern allows pattern formation whose cross-section is up-side-down taper, and burying material is easily buried between the patterns.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for forming a thin film pattern on a substrate, and more particularly to a technique for forming a plating frame for a thin film magnetic head.

0002

2. Description of the Related Art FIG. 2 shows a perspective sectional view of a thin film magnetic head. The thin film magnetic head consists of a coil 3 forming a spiral pattern on a lower magnetic pole 5, and an upper magnetic pole 6 arranged to interlink with the coil 3. An insulating material 4 is filled between the coil patterns and between the coil 3 and the lower and upper magnetic poles 5 and 6.
Coil 3 and lower and upper magnetic poles 5 and 6 interlinked therewith
electrically insulated and mechanically supported.

A method of manufacturing such a thin film magnetic head is to form a lower magnetic pole 5 on a substrate S, bury the lower magnetic pole 5 with an insulating material 4, and form a coil 3 thereon. Next, the coil 3 is embedded with an insulating material 4 to form a second layer of the coil 3. In this way, element patterns are sequentially formed and filled with the insulating material 4, which is repeated to form a thin film magnetic head as shown in FIG.

However, as the insulating material 4, Al2O3
Alternatively, when SiO2 is used by forming a film by sputtering, CVD, etc., the surface shape of the embedded pattern (the cross-sectional shape of the coil 3 in the case of a thin-film magnetic head) is shown in Fig. 4.
If the aspect ratio of the groove is high, the problem is that the groove is not filled in sufficiently, resulting in a gap 7. Here, the aspect ratio is defined as the ratio h/w of the height h and width w of the groove.

[0005] Here, the frame plating method, which is a method of forming the coil 3, will be explained with reference to FIG.

In the conventional frame plating method, after applying a positive resist 1, a plating frame 8 is formed by exposure and development using a mask with an inverted coil pattern (see FIG. 3).
a)]. Next, C, which is a coil material, is placed between the plated frames 8.
u is deposited as a coil 3 by electrolytic plating [Figure 3
(b)]. Finally, the positive resist 1, which is the plating frame material, is removed to complete the creation of the coil 3 [Figure 3 (
c)].

[0007] Even if a negative resist is used as a plating frame material, a plating frame cannot be formed because sufficient resolution cannot be obtained. Therefore, most of the frame materials used are positive resists.

[0008]

However, when a pattern is formed using the positive resist 1, the cross-sectional shape of the plating frame tends to become trapezoidal due to the influence of the aspect ratio as described above [FIG. 3(a)]. Therefore, when a material is deposited by plating between the plating frames 8 having trapezoidal cross sections, the formed plating pattern has an inverted trapezoidal cross-sectional shape [FIG. 3(a)].

When a sputtered film is used as the insulating material 4, one of the factors that makes embedding difficult is the cross-sectional shape of the coil. In other words, when embedding a structure with such an inverted trapezoidal cross-sectional shape by a method such as sputtering, the overhang of the inverted trapezoidal shape becomes an obstacle, and particles are not sufficiently deposited between the coils, making it impossible to embed the structure. The membrane quality also becomes fragile.

0010

[Means for Solving the Problems] Accordingly, in the present invention, a trapezoidal pattern is formed using a positive resist, and the positive resist and the positive resist are mutually dissolved in the developer solvent or developer rinse in the gaps between the trapezoidal patterns. No different kind of organic material to fill negative resist. Thereafter, only the positive resist is removed to form a plating frame.

[0011]

[Operation] As a result, the cross section of the organic material after removing the positive resist becomes an inverted trapezoid. Therefore, if a coil is formed using a pattern having an inverted trapezoidal cross section as a plating frame, a coil having a trapezoidal shape can be obtained.

Embedding with a trapezoidal pattern does not prevent sputtered particles from reaching the bottom surface, making embedding easier than with a coil having the same pitch pattern, and improving film strength.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example in which the present invention is applied to a coil forming plating process for a thin film magnetic head will be described with reference to FIG.

First, a desired coil pattern was formed using a novolac resin positive resist 1. Using a mask with a predetermined pattern, a wavelength of 250-400n
The film was exposed to ultraviolet light of m and then developed with an alkaline aqueous solution to form a pattern.

A synthetic rubber negative resist 2 was further coated on this pattern [FIG. 1(a)].

Next, the negative resist 2 covering the surface of the positive resist 1 was removed by a resist removal method using O2 plasma until the surface of the positive resist was exposed. At this time, the temperature of the resist was made not to rise above 90 to 100°C [FIG. 1(b)].

Here, the wafer is again exposed to wavelengths of 250 to 45.
Both positive and negative resists were exposed by irradiating the entire surface with 0 nm ultraviolet rays. As a result, the positive resist becomes soluble, while the negative resist undergoes a polymerization reaction and becomes insoluble.

The wafer in this state was developed with a positive resist developer which is an alkaline aqueous solution. Development was carried out for a longer than normal development time. This is because the developing solution cannot be sufficiently supplied to the surface between the resist grooves because the cross section of the pattern is an inverted trapezoid. The cross section of the pattern after development is shown in Figure 1 (
As shown in c), it showed an inverted trapezoid.

[0019] This substrate was coated with Cu using electrolytic plating method.
was precipitated [Figure 1(d)].

Next, the negative resist pattern 2 was removed by O2 plasma treatment, leaving only the coil [FIG. 1(e)
)].

When an insulating material was deposited on this coil by sputtering, a highly reliable insulating film without cavities could be created.

In this embodiment, a negative resist is used as the second material embedded between the first patterns, but a non-photosensitive synthetic rubber material may also be used.

[0023]

[Effects of the Invention] According to the present invention, it is possible to create a pattern with high resolution and high aspect ratio, and whose cross section has an inversely tapered shape.

By adapting this to a thin film magnetic head, the coil shape can be made into a trapezoid, and it becomes easy to embed an insulating material by sputtering or the like.

[Brief explanation of the drawing]

[Fig. 1] An explanatory diagram of the manufacturing process of a thin film magnetic head to explain one embodiment of the present invention.

[Figure 2] Perspective cross-sectional view of thin-film magnetic head

[Figure 3]
Explanatory diagram of the conventional coil forming process

[Figure 4] Explanatory diagram for explaining coil manufacturing for a conventional thin-film magnetic head

[Explanation of symbols]

1. Positive resist 2 Negative resist 3 Coil 4 Insulating material 5 Lower magnetic pole 6 Upper magnetic pole 7 Cavity 8 Plated frame

Claims (3)

[Claims] Claim 1: Using photolithography technology, a first pattern is formed by exposure and development, and then the first pattern and the first pattern do not dissolve together in a developer solvent or a developer rinse. An element characterized in that a second material is filled between the first patterns and exposed again using photolithography technology to remove only the first pattern and leave the second pattern as an inverted pattern. How to form a pattern. 2. The device pattern forming method according to claim 1, wherein a novolac resin-based positive resist is used as the first pattern and a synthetic rubber-based negative resist is used as the second material. 3. A plating frame characterized in that the inverted pattern formed by the method according to claim 1 is used as a plating mask.