JPH03154214A - Formation of photoresist pattern - Google Patents

Abstract

PURPOSE:To form thick-film patterns having a perpendicular section and high reliability by laminating and applying plural times a photoresist liquid of the same kind on a substrate to form a photoresist layer of a desired film thickness and patterning the layer, then subjecting the resist patterns of the thick films formed in such a manner to plating, etc. CONSTITUTION:The photoresist liquid of the same kind is laminated and applied plural times on the substrate 5 to form the photoresist film 11 of the desired film thickness. This photoresist film 11 is subjected to patterning 5 by repeating plural times of exposing and developing with the same mask to form the resist patterns 12 from which the photoresist film 11 is removed on the substrate 5. The patterns 13 of the required film thickness are formed on the parts of the resist patterns 12 by plating or vacuum film formation. After the resist film 11 is removed, overcoating layers 14 are formed to the required parts including the patterns 13 and are polished down to the line of an alternate long and short dash line X, by which the patterns 13 are exposed as terminals 13. The substrate is simultaneously cut at the line of an alternate long and short dash line Y.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a method for forming a thick film photoresist pattern in a wafer process for magnetic heads, etc., and aims to form a highly reliable thick film pattern with a vertical cross section. A photoresist film of a desired thickness is formed by applying the same type of photoresist solution multiple times on the substrate, and the photoresist film is patterned by repeating multiple exposures and development using the same mask. A pattern having a desired thickness is formed by plating or vacuum film formation on the portion of the resist pattern from which the film has been removed.

[Industrial application field]

The present invention relates to a method for forming a thick film photoresist pattern in a wafer process for magnetic heads and the like.

With the miniaturization and higher performance of thin-film magnetic heads in recent years, there is a demand for thicker and more perpendicular cross-sectional shapes for terminal layers, etc. that conduct with external electrical circuits, and a method for forming thick-film photoresist patterns that can meet this demand has been developed. is requested to be provided.

[Conventional technology]

For example, a thin film magnetic head 1 to which the present invention is applied reads and writes data onto an end surface of a structure 2 made of ceramic or the like having an air bearing surface 2a using a process similar to that of a semiconductor, as shown in the perspective view of FIG. 2(a). A thin film element 3 for use is formed.

The connection between the thin film element 3 and an external electric circuit (not shown) is formed at the end of the lead 3a of the thin film element 3, as shown in the sectional view taken along line A-A in FIG. This is done via the connected terminal 4.

The formation method will be described with reference to the explanatory diagram of FIG.

First, as shown in FIG. 5A, a conductive layer 6 for plating is formed on a substrate 5 made of ceramic or the like, and then a photoresist solution is applied thereon and dried to form a photoresist film 7.

The maximum thickness of the photoresist film 7 at this time is about 15 μm.

Next, as shown in FIG. 2B, unnecessary portions of the resist are removed by exposure, development, washing with water, and drying to obtain a resist pattern 8.

Then, as shown in FIG.
A terminal 4 with a thickness of ~100 μm is formed.

Next, as shown in FIG. 4(d), after removing the resist film 7, an overcoat layer 9 of, for example, alumina is formed on the required portions including the terminals 4 by a vacuum film forming method such as vacuum evaporation or sputtering.

[Problem to be solved by the invention]

In the terminal formed by the above method, the photoresist film thickness is extremely thin compared to the thickness of the terminal, and the cross-sectional shape of the terminal becomes mushroom-shaped as shown in FIG. 3(C).

For this reason, when an overcoat layer is formed on the terminal as shown in FIG. 4(d), the bottom portion becomes a shadow, preventing alumina from adhering and creating a cavity 10.

In order to make a thin film magnetic head, after forming the pattern, polish it horizontally to the line indicated by the dashed dotted line X to expose the terminals 4.
Perform the work of cutting vertically along the one-dot chain line Y.

Then, since the adhesion area of the overcoat layer to the substrate in the cavity 10 portion is small, there is a problem in that the portion 9a of the overcoat layer is chipped when cutting along the dashed line Y.

In order to solve this problem, it is possible to use a photoresist solution compatible with thick films, but there is no one that can satisfy the pattern accuracy of 5 to 10 μm with a film thickness of 50 to 100 μm.

An object of the present invention is to form a thick film pattern (terminal) with a highly reliable vertical cross section.

[Means to solve the problem]

In order to achieve the above object, in the present invention, as shown in the explanatory diagram of FIG.
1 is formed, patterning is performed on the photoresist film 11 by repeating multiple exposures and development using the same mask,
A pattern 13 having a desired thickness is formed on the portion of the resist pattern 12 from which the photoresist film 11 of the substrate 5 has been removed by plating or vacuum deposition.

[Effect]

A photoresist layer with a desired thickness is formed by applying the same type of photoresist solution multiple times.

By performing plating or vacuum film formation on the thick film resist pattern formed on this photoresist layer, a thick film pattern with a vertical cross-sectional shape can be obtained.

〔Example〕

FIG. 1 shows an embodiment of the present invention.

Identical parts are designated by the same reference numerals throughout the figures.

In the present invention, as shown in the explanatory diagrams of FIGS. 1(a) to 1(d), a photoresist film 11 of a desired thickness is formed by coating the same type of photoresist solution multiple times on the substrate 5. Then, the photoresist film 11 is patterned by repeating exposure and development multiple times using the same mask, and the photoresist film 11 on the substrate 5 is removed to form a resist pattern 12.
A pattern 13 with a desired thickness is formed by plating or vacuum deposition on the part.
It is designed to form a .

That is, as shown in FIG. 5A, first, a conductive layer 6 for plating is formed on a substrate 5 made of ceramic or the like, and then a photoresist solution is applied thereon and dried to form a first photoresist film 1.
Form 1a.

The maximum thickness of the photoresist film 11a at this time is approximately 15 μm.

Next, the same type of photoresist solution is applied onto this photoresist film 11a and dried to form a second photoresist film 11b.

The thickness of the photoresist film 11b at this time is about 35 μm.

Further, the same type of photoresist solution is applied onto this photoresist film 11b and dried to form a third photoresist film tic.

The thickness of the photoresist film 11b at this time is about 40 μm, and the total film thickness of the photoresist 11 is 90 μm, which is a desired thickness.

If further film thickness is required, it can be obtained arbitrarily by repeating this process.

Once the photoresist layer 11 with the desired thickness is formed, patterning is performed by repeating multiple exposures using the same mask, development, washing with water, and drying as shown in Figure (b). A resist pattern 12 having a shape is obtained.

Then, as shown in FIG. 5C, a terminal 13 having a thickness of 50 to 100 μm is formed by copper plating, for example, on the conductive layer 6 for plating of the substrate 5 on which the resist pattern 12 is formed.

Further, as shown in FIG. 1D, after removing the resist film 11, an overcoat layer 14 of, for example, alumina is formed on required portions including the terminals 13 by a vacuum film forming method such as vacuum evaporation or sputtering.

Thereafter, in order to form a thin film magnetic head, the terminals 13 are exposed and the terminals 13 are polished to the line indicated by the dashed line
Cut along the dotted chain line Y.

As described above, when forming the terminal 13 with a thickness of 50 to 100 μm using copper plating or the like, the thickness of the resist pattern 12 is sufficient and its cross-sectional shape is vertical, so that the terminal 13 becomes mushroom-shaped. There's nothing wrong with that.

Therefore, even if the overcoat layer 14 is cut along the Y line, the overcoat layer 4 will not be chipped.

Although the above explanation has been made by applying the present invention to the terminal forming process of a thin film magnetic head, the present invention is not limited to the terminal forming process, and can also be applied to other processes that require the formation of a vertical cross-sectional shape using a thick film photoresist. It can also be applied to

〔Effect of the invention〕

By applying the photoresist pattern forming method of the present invention to, for example, the production of thin-film magnetic heads, it becomes possible to form terminals with vertical cross sections, resulting in highly reliable products, which has great economic and industrial benefits. It has the effect of

Figure 2(b) is a sectional view taken along line A-A in Figure 3(a), and Figure 3(a)
) to (d) are explanatory diagrams of a method for forming a terminal using a conventional photoresist pattern forming method.

In the figure, 1 is a thin film magnetic head, 2 is a structure, 3 is a thin film element, 3a is a lead, 4.13 is a terminal, 5 is a substrate, 6 is a conductive layer for plating, 7.11 is a photoresist film, 8.12 is a resist pattern, 9.14 is an overcoat layer, 10 is a cavity, 11a is a first photoresist film, flb is a second photoresist film, and 11c is a third photoresist film.

[Brief explanation of the drawing]

1(a) to 1(d) are explanatory diagrams of a method for forming terminals by the photoresist pattern forming method of the present invention, and FIG. 2(a)
) is a perspective view of the thin-film magnetic head, (b) (C) A-A sectional view of the thin-film magnetic bed (α) (πdω)

Claims (1)

[Claims] A photoresist film (11) having a desired thickness is formed by coating the same type of photoresist solution multiple times on the substrate (5), and the photoresist film (11) is coated with the same mask. Patterning is performed by repeating exposure and development multiple times, and a pattern (of desired thickness) is formed by plating or vacuum deposition on the portion of the resist pattern (12) from which the photoresist film (11) of the substrate (5) has been removed. 13) A photoresist pattern forming method characterized by forming.