JPS6111913A - Formation of pattern - Google Patents

Abstract

PURPOSE:To identify distinctly the positions at both side ends of reference markers for positioning formed on a substrate by removing preliminarily the photoresist film on the reference markers for positioning. CONSTITUTION:An opaque film 28 consisting of aluminum is etched away by phosphoric acid (H3PO4) with a photoresist film 29 as a mask. A photomask 31 is further installed on the substrate and UV rays are irradiated thereon to expose a photoresist film 27 and thereafter the film 27 is removed by development, then a lower conductive layer 26 consisting of copper is removed by an ion etching method, etc. A lower thermoset photoresist film 25 is removed by using an ion milling method in succession thereto. The reference markers 23 for positioning are thereby formed without having the thick thermoset film 25 and the opaque film 28 thereon. The easy and exact mask alignment of the reference patterns 17 for positioning of a photomask 16 for forming the frame-shaped pattern of fine coils to the markers 23 is thus made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an improvement in a method for forming a pattern of a photoresist film, which serves as a mask for forming a conductor layer coil pattern of a thin film magnetic head, for example.

伽）Technical Background Recently, magnetic heads have become highly accurate and highly efficient.
Carbonization is required, and a magnetic head that satisfies these conditions is a compact thin-film magnetic head that has a steep magnetic field distribution that contributes to recording, can perform high-density recording, and can be produced in bulk at a lower price and with uniform characteristics. Various heads have been proposed.

(e) Prior Art and Problems The above-mentioned thin film magnetic head is as shown in the plan view of FIG. 1 and in FIG. 2, which is a cross-sectional view of the main part of FIG. For example, a lower magnetic layer 2 made of permalloy (Ni-Fe) is formed on a substrate 1 made of photoceram or the like into a predetermined pattern using sputtering, vapor deposition, plating, photolithography, ion etching, etc. A 5i02 film 3A is formed on the upper surface of the lower magnetic layer 2 to form a gap, and a resin insulation yI3 made of a hardened photoresist film is further formed thereon. Further, on this resin insulating film 3, a conductor layer coil 4 made of copper (Cu) or the like is formed in a predetermined spiral pattern by a mask plating method. More carp/L
A resin insulating film 5 made of a photoresist film is formed on the resin insulating W2B including the conductor layer 4, and an upper magnetic layer 6 is further formed in a predetermined pattern by photolithography and ion etching. However, the lower magnetic layer 2 and the upper magnetic JW 6 are formed into a U-shape in terms of a magnetic circuit, forming a thin film magnetic head.

By the way, in order to reduce the load on the amplifier for generating the recording current of such a thin film magnetic head and to operate it in a high frequency region, the coil conductor layer 4 must be formed thickly.
In order to form a thick coil conductor layer in this way, a mask plating method is used. In this mask plating method, a thin conductor layer made of copper (not shown) is deposited on the resin insulating film 3 using a sputtering method or the like, and then a photoresist film is applied on top of this, and this photoresist film is then coated using a photolithography method. A reverse pattern of the coil conductor layer to be formed by forming a frame-like pattern that becomes a plating frame,
From this patterned photoresist film, electroplating is performed using the bar-shaped pattern as a mask and the copper conductor layer as an electrode, and then the photoresist film that serves as the plating frame and a thin film of the copper conductor layer is removed to form a copper coil conductor layer 4.

The conventional method for forming a frame-shaped pattern made of such a photoresist film will be explained using FIG. 3 and FIG. A positioning reference marker 11 consisting of four squares spaced apart from each other by a predetermined distance is formed into a predetermined pattern using a sputtering method, a vapor deposition method, a plating method, a photolithography method, an ion etching method, or the like. Next, a 5i02 film 3^ is formed on this substrate 1 by sputtering or the like, and then a photoresist film is applied thereon and cured by heating to form a resin insulating film 3.Next, a mask plating film is formed on the substrate. After forming a copper conductor layer 12 that will become an electrode by sputtering, a photoresist film 13 that will become a plating frame is applied thereon, and then an opaque film 14 made of aluminum is further formed on this by sputtering. Furthermore, a photoresist film 15 for patterning the non-transparent film 14 is formed thereon. Next, a predetermined photomask 16 for producing a frame-like pattern of fine coils is placed on the substrate 1, and the cross-shaped edge A of the alignment reference pattern 17 of this photomask 16 is aligned with the relationship shown in FIG. Mask alignment was performed by matching the square edge B of the alignment reference marker 11 with the protruding edge of the photoresist film 15 that protruded in accordance with the shape of the alignment reference marker 11.

The reason for forming such a non-transparent film 14 is the third reason.
As shown in the figure, when forming the photoresist film 13 for forming a frame-shaped pattern formed on the heat-cured resin insulating film 3 having steps into a rod-shaped pattern for mask plating with a predetermined dimension with high precision, it is necessary to It is necessary to install the photomask along the surface of the photoresist film 13 for forming a bar-shaped pattern coated on the resin insulation 11!3. However, the photoresist film 1 for forming this frame-shaped pattern
3 is formed thickly and has steps, so if the mask is directly placed and exposed, the pattern precision will be insufficient.
l! The opaque film 14 is formed in advance in a predetermined pattern, and the opaque film 14 is coated with the butter.
This is because the lower photoresist film IS is to be formed into a predetermined bar-shaped pattern with high precision using 1114 as a mask.

By the way, in the above conventional method, the resin insulating film 3 made of a thick photoresist film with a thickness of approximately 5 μm is formed on the alignment reference marker 11, and due to the presence of this thick photoresist film, the substrate surface of the reference marker 11 and As a result, the position corresponding to the edge B of the alignment reference marker 11 on the surface of the photoresist film 156 becomes blurred and unclear, and the top layer of photoresist 11115 is There is a problem that mask alignment for patterning cannot be done accurately.

(dl Purpose of the Invention The present invention eliminates the above-mentioned problems, and by removing the photoresist film on the alignment reference markers formed on the substrate in advance, the positions of both ends of the alignment reference markers can be clearly determined. The object of the present invention is to provide a novel pattern forming method that allows identification.

(e) Structure of the invention, the above object is to deposit an opaque film on a first photoresist film coated on a substrate, further form a second photoresist film on the opaque film, In a pattern forming method comprising the step of patterning a second photoresist film and then forming the non-transparent film in a predetermined pattern using this as a mask, forming the second photoresist film in a predetermined pattern. Before doing so, the second photoresist film, the non-transparent film, and the first photoresist B111 on the region of the reference mark previously formed on the substrate are sequentially and selectively removed to expose the reference mark. This problem is solved by the pattern forming method of the present invention having steps. □That is, on the alignment reference marker formed on the substrate in the same process as the lower magnetic layer, an opaque layer is formed in advance to pattern the photoresist 1113, which will become the plating frame, with high precision. By removing the optical film 12 and the photoresist film 3, which is a thicker resin insulating film, in advance, both ends of the alignment reference marker 17 can be detected with high precision, and the alignment reference pattern of the photomask and the alignment reference marker are high. This allows for accurate mask matching.

(f) Embodiment of the Invention Hereinafter, an embodiment of the invention will be described in detail with reference to the drawings.

FIG. 5 to FIG. 10 are cross-sectional views showing one embodiment of the pattern forming method of the present invention.

As shown in FIG. 5, a magnetic film made of permalloy is deposited on a substrate 21 made of photoceram by sputtering, vapor deposition, or plating, and then a magnetic film made of permalloy is deposited on a substrate 21 made of photoceram using a photolithography method, an ion etching-puffer method, or the like. Then, 5i0 is deposited on the substrate by sputtering or the like to form a lower magnetic layer 22 with a predetermined pattern and an alignment reference marker 23.
After forming two films 24, photoresist) y! After applying 25,
Resin insulation IIl by heating and curing! Form 25. Furthermore, a copper conductor layer 26 is formed on the substrate by sputtering to serve as an electrode when forming a coil conductor layer. Next, a photoresist film 2 is placed on top of it, which will serve as a plating frame when forming a coil conductor layer.
7 is applied and formed. Then, after forming an undesired light III+ 28 made of aluminum by sputtering, a photoresist film 29 serving as a mask for patterning the non-transparent film 28 is applied thereon.

Next, as shown in FIG. 6, a photomask 30 is placed on the substrate, and ultraviolet rays are irradiated from above the mask 30 to expose it in a predetermined pattern. At this stage of mask alignment, it is preferable that the region of the alignment reference marker 23 be exposed to light within a predetermined range to the extent that it does not affect the patterns formed elsewhere, so the mask alignment does not have to be performed with high precision. .

Next, as shown in FIG. 7, the thus exposed photoresist film 29 is developed. Furthermore, as shown in the figures in Chapter 1, the photoresist W! patterned in this way is used. Using 29 as a mask, the lower aluminum opaque film 28 is coated with phosphoric acid (H
a Remove by etching with PO4). Further, as shown in FIG. 9, a photomask 31 is placed on the substrate, the photoresist film 27 is exposed by irradiation with ultraviolet rays, the photoresist film 27 is removed by development, and then the lower part is removed by ion etching or the like. After removing the copper conductor layer 26, the lower heat-cured photoresist III! 25 is removed using an ion milling method. In this way, the 10th
As shown in the figure, on the alignment reference marker 23,
Thick photoresist that cures with heat) y! 25, and opaque Ill! 2B is removed, so that it becomes possible to easily and accurately align the alignment reference pattern 17 of the photomask 16 for forming a rod-like pattern of fine coils with the alignment reference marker 23.

In this embodiment, the method for forming a thin film magnetic head has been described as an example, but the pattern forming method of the present invention can also be applied to the manufacturing of semiconductor devices having a multilayer wiring structure such as LSI. is also applicable.

(g) Effects of the Invention According to the method of the present invention described above, the reference pattern for alignment of a photomask can be easily aligned with the alignment reference marker formed on the substrate with high precision, so that The photoresist film of
If such a method is used to manufacture a thin film magnetic head or a semiconductor device, the thin film magnetic head or semiconductor device can be easily and precisely formed.

4. +f! ! A simple explanation of J side Figure 1 is gi1m! A plan view of the magnetic head, Figure 2 is the first
FIGS. 3 and 4 are sectional views showing the conventional pattern forming method; FIGS.
The figures up to FIG. 10 are cross-sectional views showing the pattern forming method of the present invention.

In the figure, 21 is a substrate, 22 is a lower magnetic layer, 23 is an alignment reference marker, 24 is a 5i02 film, and 25°2
7.29 is a photoresist film, 26 is a conductor layer, 28 is an unwanted light film, and 30.31 is a photomask.

Figure 1 Figure 2 3m 4th Wi

Claims (1)

[Claims] A non-transparent film is deposited on the first photoresist film coated on the substrate, a second photoresist film is further formed on the non-transparent film, and the second photoresist film is patterned. In a pattern forming method comprising the step of forming the non-transparent film in a predetermined pattern using a mask as a mask, before forming the second photoresist film in a predetermined pattern, a reference previously formed on the substrate is used. A pattern forming method comprising the step of sequentially selectively removing the second photoresist film, the non-transparent film, and the first photoresist film on the mark region to expose the reference mark.