JPH03120606A - Pattern forming method and thin film magnetic head formed using this method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a pattern forming method for forming a fine thin film pattern and a thin film magnetic head formed using this method, and particularly relates to a pattern forming method for forming a fine thin film pattern and a thin film magnetic head formed using this method. The present invention relates to a pattern forming method suitable for eliminating pattern omission, chipping, or deformation caused by poor adhesion, and a thin film magnetic head formed using this method.

[Prior Art] As is well known, in the manufacturing process of thin film devices, a so-called photoetching technique using a resist for microfabrication of thin films is mainly used. In particular, in recent years, with the progress of miniaturization of processing dimensions, processing methods with less undercuts, such as mono-reactive ion etching and ion milling, have come into use. Although these methods have excellent one-dimensional etching efficiency, the resist is damaged by high-energy ions during etching, so a resist with high etching resistance is required. For this reason, various resist materials have been developed; for example, resists containing phenol novolac polymers as a main component have relatively high etching resistance.

However, as the demand for finer patterns increases, resists with better etching resistance are required.For example, in the case of ion milling using an Ar ion beam, the etching speed of known resists is limited. 1 or more for the material to be processed, and usually requires a film thickness that is at least twice the thickness of the material to be processed. This was a cause of poor processing accuracy.

In order to solve the above-mentioned problems, Japanese Patent Application Laid-Open No. 63-7643
No. 8 proposes a method of forming a pattern using a two-layer film consisting of a carbonaceous thin film and a silicon-containing organic polymer thin film.

Further, Japanese Patent Laid-Open No. 168810/1983 proposes a method of patterning the magnetic material of a thin film magnetic head using two layers of carbon and photoresist.

[Problems to be Solved by the Invention] The prior art has a problem in that the adhesion between the carbonaceous thin film and the processed thin film is poor, and the carbonaceous thin film peels off during the processing process. As a result, there was a problem that the pattern was missing, chipped, or deformed, resulting in poor pattern accuracy and could not be put to practical use. It is an object of the present invention to provide a pattern forming method that prevents peeling of the pattern and prevents pattern omission, chipping, or deformation.

A second object of the present invention is to provide a pattern forming method capable of forming highly accurate patterns.

Furthermore, a third object of the present invention is to provide a pattern forming method that can remove the first layer and the second layer and form a pattern only on the thin film to be processed.

Furthermore, a fourth object of the present invention is to provide a pattern forming method capable of forming a highly accurate pattern without omission, chipping, or deformation even on a thin film to be processed having steps. .

The fifth object of the present invention is to mainly consist of C.
An object of the present invention is to provide a thin film magnetic head having a highly accurate pattern using a three-layer film with excellent adhesive properties.

[Means for Solving the Problems] The first object is to form a first layer containing Si on a thin film to be processed on a substrate, and to form a first layer containing mainly carbon on the first layer.
forming a second layer comprising:

forming a third layer made of an organic polymer containing Si that is sensitive to light or radiation on the second layer; forming a predetermined pattern on the third layer; a step of patterning the second layer using the formed pattern as a mask; a step of removing the third layer; and a step of removing the third layer.
a step of patterning the first layer using the pattern formed on the layer as a mask; and a step of forming a predetermined pattern on the processed thin film using the pattern formed on the second layer and the first layer as a mask. This is achieved by having.

The second purpose is to place the film on the thin film to be processed on the substrate.

A step of forming a first layer made of a material with excellent adhesion to the thin film to be processed and the next second layer, and applying Ar on the first layer.
The ion milling speed using gas is slower than the thin film to be processed and 0. The dry etching speed using
forming a second layer of a material whose dry etching rate is slower than that of the second layer on the second layer; forming a predetermined pattern on the third layer; patterning the second layer using the pattern formed on the third layer as a mask; removing the third layer; patterning the first layer using the formed pattern as a mask;

This is achieved by forming a predetermined pattern on the thin film to be processed using the patterns formed on the second layer and the first layer as a mask.

The third purpose is to remove the first layer and the second layer after the step of forming a predetermined pattern on the thin film to be processed using the pattern formed on the second layer and the first layer as a mask. This is achieved by having the following.

The fourth objective is achieved by forming a pattern on the thin film to be processed having a one-step difference.

The fifth object is achieved by patterning the track portion of the thin film magnetic head using the pattern forming method.

[Operation] In the present invention, a resist pattern is transferred to a second layer mainly made of C, and etching is performed using the pattern of the second layer as a mask to form a predetermined pattern on a thin film to be processed. In this case, since the second layer is formed mainly of C, it has high resistance to high-energy ions such as those produced by ion milling, and a sufficient selectivity can be achieved with a thin film. Also, 0. Since it is easily etched by plasma, high-precision patterning of difficult-to-process materials can be easily achieved by combining it with a resist that has high resistance to plasma, such as a resist containing Si.

Furthermore, in the present invention, since a material containing Si is used for the first layer, the adhesion between the thin film to be processed and the second layer (carbon layer) is improved. This makes it possible to form a pattern without omissions, chips, or deformations, and to perform photoetching with high precision.

Furthermore, the present invention includes a step of forming a first layer made of a material with excellent adhesiveness to the thin film to be processed and the next second layer on the thin film to be processed on the substrate; forming a second layer made of a material whose ion milling speed using Ar gas is slower than the thin film to be processed and whose dry etching speed using Ot is faster than the next third layer; forming a third layer made of a material whose dry etching rate is slower than that of the second layer using O2; forming a predetermined pattern on the third layer; and forming a pattern on the third layer. a step of patterning the second layer using the mask as a mask; a step of removing the third layer; and a step of patterning the first layer using the pattern formed on the second layer as a mask.

Since the method includes the step of forming a predetermined pattern on the thin film to be processed using the patterns formed on the second layer and the first layer as a mask, it is possible to form a pattern with even higher precision.

Further, in the present invention, after the step of forming a predetermined pattern on the thin film to be processed using the patterns formed on the second layer and the first layer as a mask, the step of removing the first layer and the second layer is provided. Therefore, it is possible to remove the first layer and the second layer and form a pattern only on the thin film to be processed.

Furthermore, according to the present invention, even on a thin film to be processed having steps, a highly accurate pattern can be formed without pattern omission, chipping, or deformation.

Further, in the present invention, since the track portion of the thin film magnetic head is patterned using a pattern forming method, the track portion of the upper core can be formed in a highly accurate pattern without missing, chipping, or deforming. .

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1(a) to 1(i) are diagrams showing an embodiment of the pattern forming method of the present invention in the order of steps.

As shown in FIG. 1, in this embodiment, (a) to (i
) process.

In the step (a), a thin workpiece 111 formed on the substrate 1
2, a first layer 3 containing Sl is formed. This first layer 3 can be formed, for example, by a vapor deposition method.

The vapor deposition method used in the present invention includes a chemical vapor deposition method such as plasma CVD using monosilane as a raw material, S
There are physical vapor deposition methods such as sputtering that use i as a target.

Next, in step (b), a second layer 4 mainly made of C is formed on the first layer 3. This second layer 4 can be formed by a vapor deposition method, for example.

i) A plug that uses the vapor of an organic compound consisting of C and H or C and H and 0 or C, H and N as a raw material?
Chemical vapor deposition methods such as CVD, thermal CVD, and photoCVD.

(2) The same raw material gas as in i) above is ionized, and the generated ions are accelerated by an electric field and collided with the substrate.

ion beam deposition method, rapid) sputtering method using graphite as a target, and evaporation method of graphite.

can be mentioned.

Next, in step (C), a third layer 5 made of an organic polymer sensitive to light or radiation and containing Si is formed on the second layer 4. In order to form this third layer 5, a wet coating method in which a solution of the material to be made up of the layer is dissolved in an appropriate solvent is coated by a method such as spin coating, and then dried to form a film, or A plasma polymerization method that uses steam as a raw material.

There are vapor deposition methods such as vacuum evaporation method. When the thin film to be processed has steps, it is better to use the vapor phase deposition method to obtain a uniform film thickness, so the material used in the wet coating method, which is preferable for high-precision patterning, is Polymer Vol. 37. , No. 6 (1988), pages 460 to 463, a resist containing Si is used. In the plasma polymerization method, a mixture of the vapors of an organic compound and a Si-containing organic compound that can form a photosensitive or radiation-sensitive polymer by polymerization, or a polymer that can be photosensitive or radiation-sensitive by polymerization is used. Any vapor of a Si-containing organic compound capable of forming molecules is used as a raw material.

Examples of organic compounds that can form photosensitive or radiation-sensitive polymers by polymerization include:

Methyl acrylate, methyl methacrylate, methyl isopropenyl ketone, styrene, p-chlorostyrene,
Examples include chloromethylstyrene, allyl acrylate, and glycidyl methacrylate. Examples of Si-containing organic compounds used by mixing with these organic compounds include:
Examples include tetramethylsilane, vinyltrimethylsilane, tetramethoxysilane, vinyltrimethoxysilane, hexamethyldisiloxane, hexamethyldisilazane, methacryloxytrimethylsilane, isopropenyloxytrimethylsilane, and the like.

Examples of the Si-containing organic compound that can form the photosensitive or radiation-sensitive polymer include divinyldimethylsilane, vinylchloromethyldimethylsilane, methacryloxytrimethylsilane, isopropenyloxytrimethylsilane, and the like.

Subsequently, in step (d), the third layer 5 is formed into a predetermined pattern by a normal lithography (exposure and development) process.

Furthermore, in step (e), the second layer 4 is patterned using the pattern formed on the third layer 5 as a mask. This patterning requires 0. A dry etching method is used. At this time, it is necessary that the etching rate of the third layer 5 is at least slower than that of the second layer 4. When the etching speed of the third layer 5 is faster than that of the second layer 4, the thickness of the third layer serving as a mask becomes thicker than the second layer 4 serving as the layer to be etched, and high-precision patterning becomes difficult. It will be disadvantageous.

In addition, 0! For dry etching using

Active ion etching (RIE) with excellent anisotropy
) is desirable.

Next, in step (f), the third layer 5 is removed.

It can be removed with a commonly used photoresist remover.

Next, in step (g), the first layer 3 is patterned using the pattern formed on the second layer 4 as a mask. When the first layer 3 is made of only Si, a pattern is formed by dry etching using, for example, CF4.

Subsequently, in step (h), the thin film 2 to be processed is patterned using the patterns formed on the second layer 4 and the first layer 3 as a mask. Ion etching or ion milling with excellent anisotropy is used for patterning. At this time, it is the second layer 4 mainly made of C that serves as a mask for the thin film 2 to be processed.

Therefore, it is also possible to omit step (g) and simultaneously etch the first layer 3 and the thin film 2 to be processed using only step (h).

Finally, in step (i), the second layer 4 and first layer 3 are removed. For removal of the second layer, 0. Dry etching using CF4 or the like is effective for removing the first layer 3. Also, this (i)
If there is no problem in using the second layer and the first layer as they are without performing this step, step (i) can be omitted.

Next, specific examples will be given and explained.

(Example 1) A silicon wafer with a thickness of 1.0 mm was placed on a silicon wafer with a diameter of 3 inches as a substrate.
A 5μ-permalloy (Ni-Fe) film was formed by sputtering to serve as a thin film to be processed.

Next, a 0.1 μm thick Si film was formed by sputtering on the permalloy film, which was the thin film to be processed, to form a first layer.

The second layer was created using the following procedure. That is, a pair of disk-shaped parallel plate electrodes with a radius of 10 am are installed inside a stainless steel vacuum chamber, one of which is electrically connected to a high frequency power source via a matching box, and the other electrode is grounded together with the vacuum chamber. The substrate was placed on the high frequency application side electrode of a plasma CVD apparatus having the above structure, and the substrate was heated to 200°C. After the vacuum chamber was evacuated to a degree of vacuum of 1X10-'Pa, n-hexane was supplied at a rate of 10 mm per minute converted to 1 atm, and the pressure inside the vacuum chamber was maintained at 2.6 Pa by adjusting the pumping speed.

Next, a high frequency power of 13.56 MHz and 200 W of power was applied to the electrode on the installation side of the substrate to generate plasma, and this state was maintained for 20 minutes, then the application of high frequency power was stopped and the substrate was taken out. Thickness 0 as second layer
．． A 9μ thick amorphous carbon layer was formed.

Next, a commercially available organosilicon resist (RU-1600P manufactured by Hitachi Chemical Co., Ltd., viscosity 15 cSt) was spin-coated on the substrate, and then the solvent was evaporated to form a third layer having a thickness of 1 μm.

Ultraviolet light was applied to the substrate that had gone through the above process through a photomask with a 5 μm line and space pattern.
After irradiation with an energy of 00+* J/al (365 nm), it was immersed in a 0.7% tetramethylammonium hydroxide aqueous solution for 2 minutes and developed to obtain a third layer pattern.

Next, this substrate was placed in the same vacuum device and on the same electrode side as when the second layer was formed, and after being evacuated, the temperature was set to 0. Gas was introduced at a rate of 5 ml per minute to bring the internal pressure to 1.3 Pa, and high frequency power of 100 W was applied for 30 minutes.

After that, 0. Stop the gas introduction, evacuate once, introduce CF4 at 5 mA/min, and reduce the internal pressure to 5 mA/min.
The exposed portion of the first layer was removed by applying high frequency power of 100 W for 5 wins again to expose the permalloy layer.

Next, this substrate was removed using a stripping solution (S-10 manufactured by Tokyo Ohka Co., Ltd.) at 80°C.
) for 10 minutes, and the third layer was removed.

Next, ion milling of permalloy was performed as follows. Place the board in the board holder, and set the acceleration voltage to 700v.
Deceleration voltage is 200V, arc voltage is 80V.

Ion milling was performed for 20 minutes under the conditions of an Ar flow rate of 15 mQ/min and an ion incidence angle of 0 degrees to remove the permalloy in the exposed portion.

When the substrate patterned as described above was observed under a microscope, no peeling was observed between Permalloy and Sl, or between Si and C.

Finally, the substrate is bonded to the second layer (C) and the first layer (S).
The second layer pattern was removed using the same equipment and under the same conditions as those used in patterning i), and then the first layer pattern was removed.

After all the steps were completed, the permalloy pattern width was measured and found that the distribution within the substrate was within the range of 5±0.2 μι, indicating excellent pattern accuracy. Furthermore, no omissions, chips, or deformations were observed over the entire surface of the pattern.

(Example 2) In exactly the same manner as in Example 1, a permalloy pattern with a thickness of 1.5 μm (width: 5 μm) was formed on a silicon wafer as a substrate.
m lines and spaces) were formed. However, in the case of this Example 2, after patterning the permalloy, the first layer (Si) and the second layer (C) are not removed, but both layers are left, and the substrate is heated on top of the second layer. Al and O were formed to a thickness of 10 μm by sputtering at a temperature of 200° C.

In Example 2, no peeling phenomenon was observed between Permalloy and Si, or between Si and C, even after the substrate was returned to room temperature after the Al, O, and films were formed.

In addition, the distribution of permalloy patterns within the substrate is 5±0.3
μ■, and had excellent accuracy.

(Example 3) A permalloy pattern was formed in the same manner as in Example 1 except for the formation and patterning of the third layer. As the third layer, an organic polymer layer sensitive to light or radiation and containing Sl, a resist film was formed by plasma polymerization. That is, using the same apparatus as that used to form the second layer (C) of Example 1, a third layer with a thickness of 0.3 μm was formed using the following procedure.

After grounding the substrate to the ground electrode heated to 80℃ and evacuating the inside of the vacuum chamber to IXIG-'Pa, a mixed gas of methyl isopropenyl ketone and vinyl trimethylsilane at a flow rate ratio of 181 (flow rate ratio) was converted to atmospheric pressure. Five cods were fed per minute, and the internal pressure was maintained at 10 Pa by adjusting the pumping speed. Next, a high frequency power of 80 W at a frequency of 13.56 MHz was applied to the electrode on the side not grounded to generate plasma, and plasma polymerization was performed for 20 minutes.

The third layer was patterned as follows. That is, irradiation with far ultraviolet rays (irradiation energy: 5000 J/ali at 254 n) was performed through a quartz mask having a 5 μm line and space pattern.
It was immersed in a mixed solvent of water and isopropyl alcohol (volume ratio: 1=4) and developed to obtain a third layer pattern.

After completing all the steps in this Example 3, the permalloy pattern width was measured, and it was found that the distribution within the substrate was 4.
．． 7±0.3μ■, and had excellent pattern accuracy. Furthermore, no pattern omissions, chipping, or low deformation was observed over the entire surface of the substrate.

(Example 4) A 10 μm thick polyimide resin (PIQ manufactured by Hitachi Chemical Co., Ltd.) was patterned with 5 μm lines and spaces on a silicon wafer, and this was used as a substrate to form a permalloy resin in exactly the same manner as in Example 3. I got a pattern. The polyimide pattern taper angle at this time was 37°±5°. Further, the permalloy pattern was formed perpendicularly to the polyimide resin pattern.

The pattern width of this Example 4 was 4.9±0.3μ■, and it had excellent accuracy. Also, missing patterns,
No chipping or deformation was observed.

(Example 5) Track width processing in manufacturing a thin film magnetic head will be described in detail below with reference to FIGS. 2 and 3.

Permalloy is sputtered onto a non-magnetic substrate 6 to a thickness of 1.5 μm, and a lower core layer 7 is formed by photo-etching.

Next, A1. A layer of 0.05 μm thick is formed by sputtering to a thickness of 0.5 μm, and a gap layer 8 is formed using a photoetching technique.

Subsequently, a polyimide resin (PIQ manufactured by Hitachi Chemical Co., Ltd.) is spin-coated, then heated and cured, and patterned using a photo-etching technique to form an insulating layer 9 with a thickness of 2 μm.

Further, Cu is formed by sputtering to a thickness of 1.5 μm, and patterned into a spiral shape using photoetching technology to form a coil 1O.

An insulating film of polyimide resin was formed on this coil 10 to form an insulating layer 11 with a thickness of 2.5 μm.

Next, permalloy is sputtered to a thickness of 1.5 μm to uniformly form the upper core layer 12 .

The upper core layer 12 thus formed was patterned in exactly the same manner as in Example 3. That is, Si3
A pattern of the upper core layer 12 was formed using a three-layer laminated film consisting of 04, 04, and the plasma polymerized film 5. Upper core layer 1
The width of the tip of No. 2 was the track width 13, and the variation within the substrate was 10±0.8 μm, indicating high processing accuracy. Furthermore, no missing, chipped, or deformed patterns were observed.

Finally, as a protective film (not shown), 10μ of Al, 03 was added.
A thin film magnetic head was obtained by sputtering to a thickness of m.

(Comparative Example) A thin film magnetic head was produced in exactly the same manner as in Example 5 without forming the first layer of Si. In the thin film magnetic head produced in this manner, some peeling occurred at the interface between the carbon and the upper core layer during ion milling of the upper core layer, and desired magnetic properties could not be obtained.

[Effects of the Invention] According to the invention described in claim 1 of the present invention described above, the step of forming a first layer containing Si on a thin film to be processed on a substrate, and the step of forming a first layer containing Si on the first layer, a step of forming a second layer made of C; a step of forming a third layer made of an organic polymer sensitive to light or radiation and containing Si on the second layer; a step of forming a pattern;
Using the pattern formed on the third layer as a mask, the second
a step of patterning the layer; a step of removing the third layer; a step of patterning the first layer using the pattern formed in the second layer as a mask; The process includes the step of forming a predetermined pattern on the thin film to be processed using the formed pattern as a mask, thereby eliminating problems caused by poor adhesion of the C film and creating a pattern that does not come out, chip or deform. This has the effect of forming a highly accurate pattern by fully utilizing the excellent ion milling resistance of the C film.

Furthermore, according to the second aspect of the present invention, a first layer made of a material having excellent adhesiveness with the thin film to be processed and the next second layer is formed on the thin film to be processed on the substrate. and ion milling speed using Ar gas on the first layer is slower than the thin film to be processed and 0. forming a second layer made of a material whose dry etching rate is faster than the next third layer using Q; a step of forming a predetermined pattern on the third layer; a step of patterning the second layer using the pattern formed on the third layer as a mask; a step of removing the layer; a step of patterning the first layer using the pattern formed in the second layer as a mask;
Since the method includes the step of forming a predetermined pattern on the thin film to be processed using the pattern formed on the first layer and the first layer as a mask, it is possible to form a pattern with even higher precision.

Further, according to the third aspect of the present invention, the second
After the step of forming a predetermined pattern on the thin film to be processed using the pattern formed on the layer and the first layer as a mask,
Since the method includes the step of removing the first layer and the second layer, it is possible to remove the first layer and the second layer and form a pattern only on the thin film to be processed.

Furthermore, according to the invention set forth in claim 4 of the present invention, a thin film to be processed having a step is targeted, and
By applying the invention described in any one of the above, to the thin film to be processed having the step difference.

This has the effect of forming a pattern with high precision without omission, chipping, or deformation.

According to the fifth aspect of the present invention, since the track portion of the thin film magnetic head is patterned using a pattern forming method, the track portion of the thin film magnetic head can be passed through the upper core without chipping or deformation, and with high accuracy. The upper core can be formed in a pattern with a high quality, and therefore has the effect of improving the quality of the upper core.

[Brief explanation of drawings]

FIGS. 1(a) to (i) are process diagrams showing one embodiment of the pattern forming method of the present invention, and FIG. 2 is a partial vertical cross-section showing an example of a thin film magnetic head formed using the pattern forming method of the present invention. 3 is an enlarged sectional view taken along the line AA' in FIG. 3, and FIG. 3 is a partial plan view of the thin film magnetic head. 1... Substrate, 2... Thin film to be processed, 3... First layer (
Si), 4... second layer (C), 5... third layer (organic polymer layer sensitive to light or radiation and containing Si)
, 6... Non-magnetic substrate for forming a thin film magnetic head, 7...
・The same lower core layer, 8... The same gap layer, 9... The same insulating layer, 10... The same coil, 11... The same insulating layer, 12
... Upper core layer, 13... Track width.

Claims (1)

[Claims] 1. A step of forming a first layer containing Si on a thin film to be processed on a substrate, a step of forming a second layer mainly consisting of C on the first layer, forming a third layer made of an organic polymer sensitive to light or radiation and containing Si on the second layer; forming a predetermined pattern on the third layer; a step of patterning the second layer using the formed pattern as a mask; a step of removing the third layer; and a step of patterning the first layer using the pattern formed on the second layer as a mask. , forming a predetermined pattern on the thin film to be processed using the patterns formed on the second layer and the first layer as a mask. 2. Forming a first layer made of a material with excellent adhesion to the thin film to be processed and the next second layer on the thin film to be processed on the substrate, and applying Ar gas on the first layer. forming a second layer made of a material whose ion milling rate using O_2 is slower than that of the thin film to be processed and whose dry etching rate using O_2 is faster than the next third layer; forming a third layer made of a material whose dry etching rate is lower than that of the second layer; forming a predetermined pattern on the third layer; and using the pattern formed on the third layer as a mask. patterning the second layer;
a step of removing the third layer; a step of patterning the first layer using the pattern formed on the second layer as a mask; and a step of patterning the first layer using the pattern formed on the second layer and the first layer as a mask. 1. A pattern forming method comprising the step of forming a predetermined pattern on a thin film to be processed. 3. In the pattern forming method according to claim 1 or 2, after the step of forming a predetermined pattern on the thin film to be processed using the pattern formed on the second layer and the first layer as a mask, the first layer and A pattern forming method comprising the step of removing the second layer. 4. The pattern forming method according to claim 1, 2 or 3, wherein the pattern is formed on a thin film to be processed having steps. 5. A thin film magnetic head characterized in that a track portion of the thin film magnetic head is patterned using the pattern forming method according to claim 1, 2 or 3.