JPH0829986A - Pattern formation method - Google Patents

Abstract

PURPOSE:To form a thin film pattern at a high accuracy by dry etching using the resist, which has high performance. CONSTITUTION:Sensitive polyimide or sensitive polyamide acid is formed into the film by the vapor phase polymerization, and this vapor phase polymerization film 1 is used as the resist so as to form the accurate pattern of the thin film 2 to be processed, which is provided under the resist. Consequently, since the film is synthesized by the vapor polymerization, generation of damage of the photosensitive group during the forming of film is eliminated so as to show the stabilized photosensitivity. Since this resist has high etching resistance, pattern can be directly formed on an organic film or a carbon film provided under the resist. Accuracy and productivity of the thin film pattern processing can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine processing method in a lithographic technique, and more particularly to a method for forming a highly accurate pattern on a thin film on a substrate by a dry etching method using a gas phase polymerization resist, and this method. The present invention relates to a method for manufacturing a thin film element formed by using.

[0002]

2. Description of the Related Art A method of forming a pattern by forming a resist pattern on a film to be processed by a vapor phase polymerization method and removing the film to be processed at a portion where there is no resist by dry etching improves the processing accuracy and productivity. This is a technology that can be expected, and various studies have been tried.

Japanese Patent Laid-Open No. 63-297435 proposes a pattern forming method using a two-layer film of a carbon film and a resist thin film formed by plasma polymerization.
In this technique, the carbon film and the resist film are formed with a high level difference to form a uniform film thickness, and the layer that exposes a pattern and the mask layer that resists physical sputtering are made of different materials. However, it was an excellent method for forming a high-precision pattern from the viewpoint of being able to reduce the film thickness.

However, in the plasma polymerization method, since a monomer having a photosensitive group is formed into a plasma state by using high frequency or the like, it is inevitable that the photosensitive group is partially decomposed by high energy of plasma. Therefore, there is a problem that the generated resist has low sensitivity.

As a method for avoiding this problem, Japanese Unexamined Patent Publication No.
In Japanese Patent Laid-Open No. -013323, a vapor deposition method is proposed. By using the vapor deposition method, it is possible to store the photosensitive groups in the film without damaging it during film formation, and to form a resist in the vapor phase on a substrate having a high level difference. This is a pattern forming method using a three-layer film.
This technology is highly effective because the carbon film, the silicon film, and the resist film are formed to have uniform thicknesses by forming steps, and the resist film, which is an organic thin film formed by vapor deposition, exhibits stable photosensitivity. It was an excellent method for precision pattern formation. However, since this vapor deposition film has low plasma resistance, a silicon film was required as the lower layer. That is, since it is a three-layer film, the number of steps is increased as compared with the case of the two-layer film in which the resist is formed by plasma polymerization, which is disadvantageous in the production process.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high precision pattern forming method using a gas phase polymerization resist having high sensitivity and high plasma resistance.

Another object of the present invention is to provide a method for manufacturing a thin film device having high productivity, which uses the above-mentioned method for forming a high precision pattern to pattern a thin film with high precision by a more simplified production process. Especially.

[0008]

The above-mentioned object is a method of forming a pattern by forming a resist pattern on a film to be processed by a vapor phase polymerization method and then removing the film to be processed at a portion without a resist by a dry etching method. In the above method, the resist is a polyimide or a polyamic acid formed by vapor deposition polymerization of a diamine containing silicon and an acid dianhydride. Further, in a method of patterning a material to be processed with a laminated film having a two-layer structure formed by forming a photosensitive upper layer on a lower layer removable by reactive plasma, the upper layer is a diamine containing silicon and an acid. This is achieved by using a polyimide or a polyamic acid formed by vapor deposition polymerization from a dianhydride. Particularly, the gas of the reactive plasma is preferably oxygen.

Further, the above object is achieved by the above-mentioned polyimide or polyamic acid containing a silicon-silicon bond in the main chain. This silicon content is 8 wt. It is desirable to set it to be at least%. Furthermore, if the weight ratio of silicon is 15 wt. % Or more is desirable in order to further improve accuracy and productivity.

Further, the above object can be achieved by manufacturing a thin film element in which a film to be processed is highly accurately patterned by using the pattern forming method.

[0011]

The resist used in the present invention is formed by vapor-phase polymerization of polyimide or polyamic acid having photosensitivity. Usually, a diamine as a raw material monomer and an acid dianhydride are mixed in a solution, and a polyamic acid is synthesized by a liquid phase reaction. When a heat treatment or the like is applied to this polyamic acid, a chemical reaction proceeds to form a polyimide. In the present invention, both monomers are vaporized in a vacuum chamber and vapor-phase reacted to deposit a polyamic acid film on the substrate. The polyimide film may be chemically changed by heat treatment or contact with an appropriate gas. At least one of the diamine and the acid dianhydride that are the raw material monomers used here has a structure exhibiting photosensitivity. Here, the photosensitivity refers to the property of being sensitive to ultraviolet rays, far ultraviolet rays, electron beams, X-rays and the like.
By utilizing this property, a resist pattern is formed by exposure. Ultraviolet rays, more preferably deep ultraviolet rays, are mainly used for exposing the silicon-containing resist. The raw material monomer used at this time may be aromatic, but it is more preferable that it has a structure not containing an aromatic ring in order to enhance sensitivity.

The vapor deposition polymerization method is a method in which a raw material monomer is heated and evaporated under reduced pressure to be deposited as a polymerized film on a substrate. Since vaporization and polymerization can be carried out at a relatively low temperature,
A polymerized film can be obtained by retaining the photosensitive groups in the raw material monomers.
Therefore, the resist film formed by vapor deposition polymerization can be expected to have high photosensitivity.

In the case where the intermediate layer below the photosensitive vapor-deposited polymer film is formed with a thin film which is easily etched by reactive plasma and hard to be physically sputtered, the pattern printed on the upper photosensitive layer is formed. It is possible to transfer the film to the intermediate layer and process the lower layer to be processed, which is made of a difficult-to-process material, with high accuracy. Here, physical sputtering refers to ion milling, reactive ion milling, reactive ion etching, or the like. For example, when oxygen plasma is used as the reactive plasma, an organic film can be used as the intermediate layer film. Further, when a carbon film is used for the intermediate layer, it is often more suitable for patterning the underlying film to be processed by etching by physical sputtering.

The resist is a polyimide or polyamic acid formed by vapor deposition polymerization of a diamine containing silicon and an acid dianhydride, and the silicon content is 8 w.
t. %, The resist film has sufficient resistance to oxygen plasma, and the resist pattern can be transferred to the organic film or carbon film with high accuracy by reactive ion etching of oxygen. FIG. 4 shows the correlation between the silicon content of this resist and etching resistance. It is a comparison of etching rates in reactive etching of oxygen. The higher the silicon content, the smaller the etching rate of the present resist by oxygen plasma and the higher the resistance. The silicon content of the resist is 15 wt. When it is at least%, it has a particularly high plasma resistance and can transfer the resist pattern to the organic film or the carbon film with higher accuracy.

Further, since the resist is formed in the vapor phase, it is possible to form a thin film with a uniform thickness even in a portion having a high step. That is, since it is possible to form a resist thin film that conforms to the unevenness within the uneven substrate surface, by adjusting the depth of focus at the time of exposure, it is possible to increase the height at the desired height of the step, the bottom, or the slope. Precision pattern formation is possible. Therefore, it is possible to realize high-precision processing with excellent productivity in manufacturing a thin film magnetic head, a semiconductor element, and the like.

[0016]

Embodiments of the present invention will be described below with reference to FIGS. First, FIG. 1 shows a pattern format method using only a vapor-deposited polymer film.

Step (a): The thin film 2 to be processed is formed on the substrate 3.

Step (b): The vapor-deposited polymer film 1 is formed thereon. The vapor-deposited polymer film used in the present invention is a polyimide or a polyamic acid formed from a diamine containing silicon and an acid dianhydride. In vapor deposition polymerization, usually, equimolar amounts of both monomers are placed in separate containers in a vacuum layer and heated to evaporate. At this time, the temperature is controlled so that the evaporation rates of both monomers are equal. The thin film thus obtained on the substrate is polyamic acid. Although the polyamic acid may be used as a resist as it is, it may be chemically changed into polyimide by heat treatment or the like to obtain a resist. Further, the vapor-deposited polymer film 1 used in the present invention is ultraviolet
A thin film that has the property of being able to form a pattern by causing a chemical reaction when exposed to deep ultraviolet rays, electron beams, X-rays, etc. and changing the reactivity or vapor pressure to a specific solvent or gas. is there.

Step (c): A desired pattern is baked (exposed) on the vapor-deposited polymer film 1 and developed to form a resist pattern. For the exposure, usually deep ultraviolet rays are used, and an appropriate value of the exposure energy is selected depending on the formation conditions of the vapor-deposited polymer film 1. Normal,
The maximum is several hundred mJ / cm ² (254 nm). A solution is generally used for development. As the developing solution, dimethylformamide, dimethylacetamide, N-methylpyrrolidone or the like, which is a good solvent for polyamic acid, is used alone, or an acid,
An alkaline aqueous solution is used, or a mixed solvent with water, methanol, ethanol or the like, which is a poor solvent for polyamic acid, is used. Alternatively, dry development may be performed under high vacuum or in a specific gas. More preferably, the development is performed simultaneously with the exposure by laser ablation.

Step (d): Dry etching is performed to transfer the resist pattern to the thin film 2 to be processed.

Step (e): The pattern of the vapor-deposited polymer film 1 is removed to obtain the pattern of the film to be processed on the substrate 3.

Next, FIG. 2 shows a pattern forming method using a two-layer structure film. This is a further preferred form of the present invention.

Step (f): The film 2 to be processed is formed on the substrate 3.

Step (g): A step of forming a material, for example, a carbon film 4, which is easily etched by oxygen plasma and hard to be physically sputtered on the thin film 2 to be processed.
The carbon film is formed by vapor deposition. As the film forming method, a plasma CVD method in which a gas containing hydrocarbon is decomposed in plasma and a carbon film is deposited, and a sputtering method in which a carbon film is knocked out by plasma ions using carbon as a target and is deposited on an opposing substrate , An ion beam deposition method of depositing a carbon film by ionizing a hydrocarbon gas and accelerating it to collide with a substrate, and a vapor deposition method of graphite.

Step (h): The vapor-deposited polymer film 1 is formed. The vapor-deposited polymer film used in the present invention is a polyimide or a polyamic acid formed from a diamine containing silicon and an acid dianhydride. In vapor deposition polymerization, usually, equimolar amounts of both monomers are placed in separate containers in a vacuum layer and heated to evaporate. At this time, the temperature is controlled so that the evaporation rates of both monomers are equal. The thin film thus obtained on the substrate is polyamic acid. Although the polyamic acid may be used as a resist as it is, it may be chemically changed into polyimide by heat treatment or the like to obtain a resist.

Step (i): A desired pattern is formed on the vapor-deposited polymer film 1 by exposure and development. For the exposure, usually deep ultraviolet rays are used, and an appropriate value of the exposure energy is selected depending on the formation conditions of the vapor-deposited polymer film 1. Usually, the maximum is several hundred mJ / cm ² . For development, dimethylformamide, dimethylacetamide, N-methylpyrrolidone or the like, which is a good solvent for polyamic acid, is used alone, or an acid or an alkaline aqueous solution is used,
A mixed solvent of water, methanol, ethanol or the like, which is a poor solvent for polyamic acid, is used. Alternatively, dry development may be performed under high vacuum or in a specific gas. More preferably, the development is performed simultaneously with the exposure by laser ablation.

Step (j): The underlying carbon film 4 is etched by using the pattern formed on the vapor-deposited polymer film 1 as a mask. The etching at this time is dry etching using oxygen plasma, that is, reactive ion etching (RI
E) is preferred. The resist pattern can be accurately transferred to the lower layer material.

Step (k): The thin film 2 to be processed is patterned by using the pattern formed on the carbon film 4 as a mask. Dry etching such as ion milling is used for this patterning. At this time, the carbon film 4 mainly serves as an etching mask.

Step (l): Usually, in the step (k), the vapor-deposited polymer film 1 is etched and removed together with a partial upper layer of the carbon film 4, but if it remains, it can be removed by dry etching or the like.

Step (m): The remaining carbon film can be left as it is and moved to the next step, or it can be removed by etching with oxygen plasma.

Next, a detailed description will be given with reference to specific examples.

<Embodiment 1> A concrete embodiment 1 will be described with reference to FIG.
Will be explained.

First, in step (a), an organic film 2 to be processed is formed on a silicon wafer substrate 3 having a diameter of 3 inches.
Was formed to a thickness of 3.5 μm. Next, in the step (b), the vapor-deposited polymer film 1 was formed on this substrate by the following procedure. As a raw material monomer, diamine and dianhydride,
Bis (4-aminophenyl) tetramethyldisilane and pyromellitic dianhydride, each of which has the structure shown below, are separately placed in a vacuum device in equimolar amounts,

[0034]

[Chemical 9]

After evacuating to a vacuum degree of 1 × 10 ⁴ Pa or more, 90% of bis (4-aminophenyl) tetramethyldisilane was used.
, Pyromellitic dianhydride to 240 ℃,
Evaporated for 100 minutes and deposited on a substrate heated to 40 ° C. The deposit is heated to 250 ° C. and then 1.57μ
A polyimide film having a thickness of m was obtained and used as a vapor-deposited polymer film 1. At this time, the silicon content is 13 wt. %. (C)
In the process, a photomask having a line-and-space striped pattern with a width of 10 μm was placed on the vapor-deposited polymer film 1 and irradiated with ultraviolet light of 500 mJ / cm ² (254 nm), and methanol and ethanol were mixed at a ratio of 2: 1 ( It was developed by immersing it in a developing solution (volume ratio). As a result, a positive resist pattern was formed and the organic film 2 was exposed.

Next, in step (d), the organic film is subjected to oxygen R
Etching was performed by IE. The condition is power 25
0 W, oxygen gas pressure 3.0 Pa, oxygen gas flow rate 50 ml
It was / min. After removing the vapor-deposited polymerized film in the step (e), the line width of the line-and-space pattern of the formed organic film was measured. As a result, the dimensional variation at 20 points in the substrate surface was 10.7 ± 0.9 μm, which was excellent. It had accuracy. The pattern shape was also good. When the etching rates of this film were compared, the rate ratio was 15.
2 (organic film / vapor-deposited polymerized film).

<Embodiment 2> A concrete embodiment 2 will be described with reference to FIG.
Will be explained.

First, in the step (f), the permalloy film 2 having a thickness of 1 μm is formed on the silicon wafer substrate 3 having a diameter of 3 inches.
Was formed. Next, in step (g), a carbon film 4 having a thickness of 1 μm was formed on this substrate by the following procedure. That is, an electrode structure in which a pair of disk-shaped parallel plate electrodes having a radius of 10 cm are provided inside a stainless steel vacuum chamber, one of which is electrically connected to a high frequency power source through a matching box and the other is grounded together with the vacuum chamber. Plasma CVD with
Place the substrate on the electrode on the high frequency side of the device,
Heated to 0 ° C. After evacuating the vacuum chamber to a vacuum degree of 1 × 10 to ⁴ Pa, 10 ml of n-hexane was supplied per minute and the evacuation rate was adjusted to maintain the pressure at 2.6 Pa. Next, high frequency power having a frequency of 13.56 MHz and power of 200 W was applied to generate plasma, and the discharge state was maintained for 20 minutes in this state, and then the application of high frequency power was stopped. Further, in the step (h), the vapor-deposited polymer film 1 was formed thereon in the same manner as in Example 1. However, the vapor deposition time was 30 minutes. The film thickness of the polyimide obtained at this time is 0.42.
μm.

In step (i), the vapor-deposited polymer film 1 was provided with the same photomask as in Example 1 to obtain 400 mJ /
Irradiation with ultraviolet light of cm ² followed by development was performed to obtain a vapor deposition polymer film 1 having a positive pattern. A 2: 1 (volume ratio) solution of methanol and ethanol was used as the developer. Subsequently, in the step (j), this substrate is placed on the same vacuum device and the same electrode side as those used when the carbon film is formed, and after evacuating, the pressure is set to 1 × 10 to ² Pa and oxygen gas is supplied every time. Minute 5
It was introduced in ml to 1.3 Pa, and high frequency power of 100 W was applied for 30 minutes. Deposition polymerized film pattern 1 in this process
Was transferred to the carbon film 4, and the permalloy in the portion without the carbon film 4 was exposed. When the etching rate at this time was measured, the rate ratio was 10.5 (carbon film / vapor deposited polymer film). The pattern transfer accuracy is very good, and the dimensional variation of the pattern in 20 places on the substrate surface is 10.10 ± 0.21μ.
It was m.

Next, in the step (k), the permalloy film 2
Ion milling was performed as follows. The substrate is installed on the ion milling machine, and the acceleration voltage is 700V and the deceleration voltage is 2
Ion milling was performed for 20 minutes under the conditions of 00 V, arc voltage 80 V, Ar flow rate 15 ml / min, and ion incident angle 30 ° to remove the permalloy in the exposed portion. Usually, the pattern of the vapor-deposited polymer film 1 is removed in this step, but if it remains, it is removed by dry cleaning or the like in step (l). By the same processing as the step (j),
In the step (m), the pattern of the carbon film 4 is removed to obtain the pattern of the permalloy film 2 on the substrate 3. The dimensional variation of 20 points in the substrate surface of the pattern formed as described above was 9.54 ± 0.43 μm, which was excellent processing accuracy. Moreover, reattachment to the side wall was not recognized.

<Third Embodiment> A concrete third embodiment will be described with reference to FIG. 1 again. 3 inch diameter silicon wafer substrate 3
The carbon film 2 which is the film to be processed is sputtered on top of
It was formed to a thickness of m. On this, as a diamine and an acid dianhydride, bis (4-aminophenyl) tetraphenyl disilane and ethylene glycol di trimellitate anhydride ester having the following structures, respectively, are installed in a vacuum apparatus in equimolar amounts separately,

[0042]

[Chemical 10]

After evacuation to a vacuum degree of 1 × 10 to ⁴ Pa or higher, bis (4-aminophenyl) tetraphenyldisilane was added to 8 times.
At 0 ° C., heat ethylene glycol di-trimellitic anhydride ester to 150 ° C. and evaporate for 30 minutes.
It was deposited on a substrate heated to ° C. 200 of this deposit
A polyimide film having a thickness of 0.52 μm was obtained by heat treatment at 0 ° C. and used as a vapor-deposited polymer film 1. The silicon content at this time is
7 wt. %. A photomask having a line-and-space striped pattern with a width of 10 μm was placed on the vapor-deposited polymer film 1 and irradiated with ultraviolet light of 500 mJ / cm ² (254 nm), and methanol and ethanol were mixed at a ratio of 2: 1 (volume ratio). It was developed by immersing it in the developer solution. As a result, a positive resist pattern was formed and the carbon film 2 was exposed. The carbon film was then etched by oxygen RIE. Etching conditions are power 250W, oxygen gas pressure 3.0P
a, the oxygen gas flow rate was 50 ml / min. The etching rate ratio at this time was 4.4 (carbon film / vapor-deposited polymer film). The line width of the line-and-space pattern of the carbon film thus formed was measured and found to be 2
The dimensional variation at 0 locations was 9.05 ± 0.88 μm.

<Embodiment 4> A specific embodiment 4 will be described with reference to FIG.
Will be explained. A carbon film 2 to be processed is 1 μm on a silicon wafer substrate 3 having a diameter of 3 inches by a sputtering method.
Formed to a thickness of. On top of this, as diamine, bis (4-aminophenyl) diphenyldisilane having the following structure

[0045]

[Chemical 11]

And the acid dianhydride (ethylene glycol dianhydride trimellitate ester) used in Example 3 were separately placed in a vacuum apparatus in equimolar amounts, and after evacuation to a vacuum degree of 1 × 10 to ⁴ Pa or more, Bis (4-aminophenyl) diphenyldisilane was heated to 80 ° C. and ethylene glycol ditrimethyl trimellitate was heated to 150 ° C., evaporated for 100 minutes and deposited on a substrate heated to 40 ° C. This deposit was heat-treated at 200 ° C. to obtain a polyimide film having a thickness of 1.88 μm, which was used as a vapor-deposited polymer film 1. A photomask having a line-and-space striped pattern with a width of 10 μm is arranged on the vapor-deposited polymerized film 1 and KrF (248
(nm) Excimer laser was irradiated for 100 seconds, and as a result, a positive resist pattern was formed. At this time, the film thickness difference between the exposed portion and the unexposed portion was 0.97 μm. Next, oxygen RIE was performed. The etching condition is power 25
0 W, oxygen gas pressure 3.0 Pa, oxygen gas flow rate 50 ml
It was / min.

<Embodiment 5> A specific embodiment 5 will be described with reference to FIG.
Will be explained. A carbon film 2 to be processed is 1 μm on a silicon wafer substrate 3 having a diameter of 3 inches by a sputtering method.
Formed to a thickness of. On top of this, bis (4-aminophenyl) dimethyldisilane and bis (tetrahydrophthalic anhydride) silane having the following structures

[0048]

[Chemical 12]

Are placed in a vacuum apparatus separately in equimolar amounts, and
After evacuation to × 10 ~ ⁴ Pa or more vacuum degree, the bis (4-aminophenyl) dimethyl disilane 100 ° C., by heating bis (tetrahydrophthalic anhydride) silane 210 ° C.,
Evaporated for 30 minutes and deposited on a substrate heated to 40 ° C. This deposit is heated to 250 ° C. and 0.45 μm
A polyimide film having a thickness of 1 was obtained, and was used as a vapor-deposited polymer film 1. At this time, the silicon content is 15 wt. %. A photomask similar to that in Example 4 was placed on the vapor-deposited polymerized film 1 to irradiate it with 400 mJ / cm ² (254 nm) of ultraviolet light,
Development was performed by immersing in a 2: 1 (volume ratio) developer solution of methanol and ethanol. As a result, a positive resist pattern was obtained. Next, the carbon film was etched by oxygen RIE. The etching conditions were a power of 250 W, an oxygen gas pressure of 3.0 Pa, and an oxygen gas flow rate of 50 ml / min. The etching rate ratio at this time was 15.7 (carbon film / vapor-deposited polymer film). When the line width of the line-and-space pattern of the carbon film thus formed was measured, the dimensional variation at 20 points on the substrate surface was 9.66.
It was ± 0.38 μm and had excellent accuracy. The pattern shape was also good.

<Sixth Embodiment> A sixth embodiment will be described with reference to FIG.
Will be explained. A carbon film 2 to be processed is 1 μm on a silicon wafer substrate 3 having a diameter of 3 inches by a sputtering method.
Formed to a thickness of. Then, bis (4-aminophenyl) tetraphenyldisilane similar to that in Example 3 and bis (tetrahydrophthalic anhydride) silane similar to that in Example 5 were separately placed in a vacuum apparatus in equimolar amounts, and 1 × 10 ~ ⁴ Pa
After evacuating to the above vacuum degree, bis (4-aminophenyl) tetraphenyldisilane was heated to 80 ° C. and bis (tetrahydrophthalic anhydride) silane was heated to 210 ° C., evaporated for 30 minutes, and heated to 40 ° C. It was deposited on top. This was heat-treated at 250 ° C. to obtain a polyimide film having a thickness of 0.58 μm, which was designated as vapor-deposited polymer film 1. At this time, the silicon content is 10 wt. %. A photomask similar to that in Example 5 was placed on the vapor-deposited polymer film 1 to obtain 300 mJ / c.
It was irradiated with m ² of ultraviolet light and immersed in the same developer as in Example 5 to develop. A positive resist pattern was formed and the carbon film 2 was exposed. The carbon film was then etched by oxygen RIE. The etching conditions are a power of 250 W,
Oxygen gas pressure 3.0 Pa, oxygen gas flow rate 50 ml / mi
It was n. The etching rate ratio at this time is 11.8.
(Carbon film / vapor deposited polymer film). When the line width of the line-and-space pattern of the carbon film thus formed was measured, the dimensional variation at 20 points in the substrate surface was 9.
It was 36 ± 0.29 μm and had excellent accuracy. The pattern shape was also good.

<Embodiment 7> A concrete embodiment 7 will be described with reference to FIG.
Will be explained. A carbon film 2 to be processed is 1 μm on a silicon wafer substrate 3 having a diameter of 3 inches by a sputtering method.
Formed to a thickness of. On top of this, bis (4-aminohexene) tetramethyldisilane having the following structure

[0052]

[Chemical 13]

Then, bis (tetrahydrophthalic anhydride) silane similar to that used in Example 5 was placed in a vacuum apparatus, and 1 × 10 ⁴
After evacuation to a vacuum of Pa or higher, bis (4-aminohexene) tetramethyldisilane was heated to 90 ° C. and bis (tetrahydrophthalic anhydride) silane was heated to 210 ° C. to evaporate for 30 minutes and then heated to 40 ° C. Deposited on top. This was heat-treated at 250 ° C. to obtain a polyimide film having a thickness of 0.37 μm, which was designated as vapor-deposited polymer film 1. At this time, the silicon content is 14 wt. %. In this vapor-deposited polymer film 1,
A photomask similar to that in Example 6 is arranged and 100 mJ /
It was irradiated with cm ² of ultraviolet light and immersed in the same developing solution as in Example 6 for development. A positive resist pattern is formed,
The carbon film 2 was exposed. Next, the carbon film was etched by oxygen RIE. Etching conditions are power 250
W, oxygen gas pressure 3.0 Pa, oxygen gas flow rate 50 ml /
It was min. The etching rate ratio at this time is 12.
It was 4 (carbon film / vapor deposited polymer film). When the line width of the line-and-space pattern of the carbon film thus formed was measured, the dimensional variation at 20 points within the substrate surface was 9.85 ± 0.35 μm, which was excellent in accuracy. The pattern shape was also good.

<Embodiment 8> A specific embodiment 8 will be described with reference to FIG.
Will be explained. A carbon film 2 to be processed is 1 μm on a silicon wafer substrate 3 having a diameter of 3 inches by a sputtering method.
Formed to a thickness of. On top of this, bis (4-aminophenyl) disilane and bis (phthalic anhydride) dimethyldisilane, each of which has the following structure

[0055]

Embedded image

Was placed in a vacuum apparatus, and after evacuating to a vacuum degree of 1 × 10 to ⁴ Pa or more, bis (4-aminophenyl) disilane was heated to 120 ° C. and bis (phthalic anhydride dimethyldisilane) was heated to 200 ° C. And evaporated for 30 minutes and deposited on a substrate heated to 40 ° C. This deposit was heat-treated at 200 ° C. to obtain a 0.70 μm-thick polyimide film, which was used as a vapor-deposited polymer film 1. The silicon content at this time is 18w.
t. %. A photomask similar to that of Example 7 was placed on this vapor-deposited polymerized film 1 and irradiated with ultraviolet light of 500 mJ / cm ² , and was immersed in the same developing solution as that of Example 7 for development. As a result, a positive resist pattern was formed. The carbon film was then etched by oxygen RIE. Etching conditions are power 250W, oxygen gas pressure 3.0P
a, the oxygen gas flow rate was 50 ml / min. The etching rate ratio at this time is 25.3 (carbon film / vapor-deposited polymer film)
Met. When the line width of the line-and-space pattern of the carbon film thus formed was measured, the dimensional variation at 20 locations within the substrate surface was 9.47 ± 0.74 μm.

<Embodiment 9> A specific embodiment 9 will be described with reference to FIG.
Will be explained. A carbon film 2 to be processed is 1 μm on a silicon wafer substrate 3 having a diameter of 3 inches by a sputtering method.
Formed to a thickness of. On top of this, bis (4-aminohexene) tetramethyldisilane and bis (tetrahydrophthalic anhydride) dimethyldisilane, each of which has the following structure

[0058]

[Chemical 15]

Was placed in a vacuum apparatus and evacuated to a vacuum degree of 1 × 10 to ⁴ Pa or higher, bis (4-aminohexene) tetramethyldisilane was heated to 100 ° C., and bis (tetrahydrophthalic anhydride) dimethyldisilane was added. Heat to 200 ° C,
Evaporated for 30 minutes and deposited on a substrate heated to 40 ° C. This deposit is heated to 200 ° C. and then 0.53 μm
A polyimide film having a thickness of 1 was obtained, and was used as a vapor-deposited polymer film 1. At this time, the silicon content is 16 wt. %. A photomask similar to that used in Example 8 was placed on this vapor-deposited polymerized film 1, and it was irradiated with ultraviolet light of 100 mJ / cm ² and developed using an alkaline aqueous solution as a developing solution. As a result, a positive resist pattern was formed. Then, as in Example 8, the carbon film was etched by oxygen RIE. The etching rate ratio at this time was 21.1 (carbon film / vapor-deposited polymer film).
Met. When the line width of the line-and-space pattern of the carbon film thus formed was measured, the dimensional variation at 20 locations within the substrate surface was 9.40 ± 0.52 μm.

<Embodiment 10> A specific embodiment 10 will be described with reference to FIG. 3 inch diameter silicon wafer substrate 3
The carbon film 2 which is the film to be processed is sputtered on top of
It was formed to a thickness of m. On top of this, bis (4-aminophenyl) silane having the following structure

[0061]

Embedded image

And bis (tetrahydrophthalic anhydride) dimethyldisilane as in Example 9 were placed in a vacuum apparatus,
After evacuation to a vacuum of 1 × 10 ⁴ Pa or higher, bis (4-aminophenyl) silane was heated to 110 ° C. and bis (tetrahydrophthalic anhydride) dimethyldisilane was heated to 230 ° C. to evaporate for 30 minutes, It was deposited on a substrate heated to ° C. This deposit is heated to 250 ° C. and 0.42
A polyimide film having a thickness of μm was obtained and used as a vapor-deposited polymer film 1.
At this time, the silicon content is 14 wt. %. A photomask similar to that of Example 9 was placed on this vapor-deposited polymerized film 1, and 300 mJ / cm ² of ultraviolet light was irradiated, and similarly to Example 9, an alkaline aqueous solution was used as a developing solution for development.
As a result, a positive resist pattern was formed. Then, as in Example 9, the carbon film was etched by oxygen RIE. The etching rate ratio at this time is 14.9.
(Carbon film / vapor deposited polymer film). When the line width of the line-and-space pattern of the carbon film thus formed was measured, the dimensional variation at 20 points in the substrate surface was 9.
It was 76 ± 0.76 μm.

<Embodiment 11> A concrete embodiment 11 will be described with reference to FIG. 3 inch diameter silicon wafer substrate 3
The carbon film 2 which is the film to be processed is sputtered on top of
It was formed to a thickness of m. On top of this, a phenylenediamine consisting of the following structure

[0064]

[Chemical 17]

And bis (tetrahydrophthalic anhydride) dimethyldisilane as in Example 9 were placed in a vacuum device,
After evacuating to a vacuum of 1 × 10 to ⁴ Pa or higher, phenylenediamine was heated to 80 ° C. and bis (tetrahydrophthalic anhydride) dimethyldisilane was heated to 230 ° C., evaporated for 30 minutes, and heated to 40 ° C. on the substrate. Deposited on. This deposit was heat-treated at 250 ° C. to obtain a polyimide film having a thickness of 0.53 μm, which was used as a vapor deposition polymerized film 1. At this time, the silicon content is 12 wt. %. On this vapor-deposited polymerized film 1, a photomask similar to that in Example 10 was placed and 200 mJ /
It was irradiated with cm ² of ultraviolet light and developed using the same developer as in Example 8. As a result, a positive resist pattern was formed. Then, as in Example 10, the carbon film was subjected to oxygen R
Etched by IE.

The etching rate ratio at this time was 8.8 (carbon film / vapor-deposited polymer film). When the line width of the line-and-space pattern of the carbon film thus formed was measured, the dimensional variation at 20 points in the substrate surface was 9.23.
It was ± 0.41 μm.

<Embodiment 12> A specific embodiment 12 will be described with reference to FIG. 3 inch diameter silicon wafer substrate 3
The carbon film 2 which is the film to be processed is sputtered on top of
It was formed to a thickness of m. On top of this, the same phenylenediamine as in Example 11 and bis (tetrahydrophthalic anhydride) tetramethyldigermane having the following structure

[0068]

Embedded image

Was placed in a vacuum apparatus, and after evacuating to a vacuum degree of 1 × 10 to ⁴ Pa or more, phenylenediamine was heated to 80 ° C.
Bis (tetrahydrophthalic anhydride) tetramethyldigermane is heated to 300 ° C. and evaporated for 30 minutes to 40 ° C.
It was deposited on a heated substrate. This deposit is 250 ℃
Was heat-treated to obtain a polyimide film having a thickness of 0.40 μm, which was used as a vapor-deposited polymer film 1. A photomask similar to that in Example 11 was placed on the vapor-deposited polymer film 1 to obtain 100 mJ / cm 2.
^It was irradiated with the ultraviolet light of ² and developed using the same developer as in Example 11. As a result, a positive resist pattern was formed. Then, the carbon film was subjected to RI of oxygen in the same manner as in Example 10.
Etched by E.

The etching rate ratio at this time was 38 (carbon film / vapor deposited polymer film). When the line width of the line-and-space pattern of the carbon film thus formed was measured, the dimensional variation at 20 points in the substrate surface was 9.72 ±.
It was 0.34 μm.

<Embodiment 13> An example in which the present invention is applied to the patterning of the upper core film (magnetic film) of the track portion in the manufacturing process of the thin film magnetic head will be described below. FIG. 3 shows a cross section of the device.

Permalloy was sputtered to a thickness of 1.5 μm on a non-magnetic substrate 3 having a diameter of 3 inches to form a lower core film 5 by a photoetching technique.

Next, 0.5% of alumina is sputtered.
The gap film 6 is formed with a thickness of μm and is formed by using a photoetching technique.

Subsequently, a polyimide resin (PI made by Hitachi Chemical
Q) is spin-coated, then heat-cured, and patterned by a photoetching technique to form an insulating film 7 having a thickness of 2 μm.

Further, Cu is formed to a thickness of 1.5 μm by sputtering, and is patterned into a coil 8 in a spiral shape by using a photoetching technique to form the coil 8.

A film of polyimide resin was formed on the coil 8 to form an insulating film 9 having a thickness of 2.5 μm.

Then, permalloy is sputtered to a thickness of 1.5 μm to form a uniform upper core film 10.

The present invention was applied to the patterning of the upper core film 10 thus formed.

That is, the pattern of the upper core film 10 was formed by using the two-layer film of the carbon film 4 and the vapor-deposited polymer film 1. First, a carbon film having a thickness of 2 μm was formed by sputtering on the upper core film. The same bis (tetrahydrophthalic anhydride) silane and bis (4-aminophenyl) dimethyldisilane as in Example 5 were used as the acid dianhydride and diamine, respectively, and a polyimide film was formed in the same manner as in Example 5.
The film thickness at this time was 0.45 μm. This was patterned into the shape of the upper magnetic film having a track width of 8.00 μm by exposure and development. RIE of oxygen was performed using the pattern of the vapor-deposited polymer film 1 as a resist, and then ion milling was performed using the carbon film 4 as a mask. The pattern of the vapor-deposited polymer film 1 was transferred to the upper core film 10.

The width of the tip portion of the upper core film 10 becomes the track width, and the dimensional variation of the track width at 30 points in the substrate is 7.77 ± 0.55 μm, which shows high processing accuracy. Further, no redeposition was observed on the side surface of the pattern.

[0081]

As described above, according to the present invention,
A highly sensitive resist film can be formed by vapor phase polymerization, and since it has high etching resistance, it is possible to directly transfer a pattern to an organic film or a carbon film as a lower layer film.
This has the effects of improving the pattern accuracy and the productivity of the film to be processed.

[Brief description of drawings]

FIG. 1 is a process chart showing an embodiment of the present invention.

FIG. 2 is a process chart showing another embodiment of the present invention.

FIG. 3 is an enlarged cross-sectional view of a part of the thin-film magnetic head.

FIG. 4 is a correlation diagram between the silicon content of the resist film and the etching resistance.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vaporized polymer film, 2 ... Thin film to be processed, 3 ... Substrate, 4 ... Carbon film, 5 ... Lower core film, 6 ... Gap film, 7 ... Insulating film, 8
... coil, 9 ... insulating film, 10 ... upper core film.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical indication location G03F 7/037 501 7/038 504 7/36 H01L 21/027 21/3065 (72) Inventor Saito Harunobu 2880 Kozu, Odawara City, Kanagawa Stock Company, Hitachi Ltd. Storage Systems Division

Claims (16)

[Claims] 1. A resist is formed by a gas phase polymerization method,
In a method of forming a pattern by removing a material to be processed in a portion without a resist by dry etching, the resist is a polyimide or a polyamic acid formed by vapor deposition polymerization of a diamine and an acid dianhydride, and the resist is a diamine and an acid diacid. A pattern forming method, wherein at least one of the anhydrides is a compound containing silicon. 2. A resist is formed by a gas phase polymerization method,
In the method of forming a pattern by removing the material to be processed without a resist by dry etching, the resist is a polyimide or a polyamic acid obtained by vapor deposition polymerization of a diamine containing silicon and an acid dianhydride containing silicon. A pattern forming method characterized by the above. 3. The pattern forming method according to claim 1, wherein the polyimide or the polyamic acid contains at least one silicon-silicon bond in the main chain of the repeating unit. 4. The silicon content of the polyimide or the polyamic acid according to claim 1, which is 8 w.
t. % Or more, the pattern forming method. 5. The silicon content of the polyimide or polyamic acid according to claim 1, which is 8 w.
t. % To be a resist for patterning an organic film or a carbon film as a lower layer by using oxygen plasma. 6. The silicon content of the polyimide or the polyamic acid according to claim 1, which is 15 or more.
wt. % Or more, the pattern forming method is characterized by exhibiting high etching resistance. 7. The silicon content of the polyimide or the polyamic acid according to claim 1, which is 15 or more.
wt. %, It becomes a resist having high etching resistance when the material to be processed of the lower layer is patterned by using oxygen plasma. 8. The diamine according to claim 1, wherein the diamine has a structure represented by the following chemical structural formula, and the functional group —R ₁ is a methyl group, an ethyl group, a phenyl group, or a hydrogen group. And the functional group -R ₂ is either a methyl group, an ethyl group, a phenyl group or a hydrogen group, and the functional group -R ₃ is a methyl group, an ethyl group, a phenyl group or a hydrogen group, A pattern forming method, wherein the functional group -R ₄ is any one of a methyl group, an ethyl group, a phenyl group and a hydrogen group. Embedded image 9. The acid dianhydride according to claim 1, wherein the acid dianhydride has a structure represented by the following chemical structural formula, and the functional group —R ₅ is a methyl group, an ethyl group, a phenyl group, or a hydrogen group. Any of the functional groups -R ₆
Is a methyl group, an ethyl group, a phenyl group or a hydrogen group, the functional group -R ₇ is a methyl group, an ethyl group, a phenyl group or a hydrogen group, and the functional group -R ₈ is a methyl group. A pattern forming method, which is one of a group, an ethyl group, a phenyl group, and a hydrogen group. Embedded image 10. The diamine according to any one of claims 1 to 3, wherein the diamine has a structure represented by the following chemical structural formula, and the functional group -R ₉ is a methyl group, an ethyl group, a phenyl group, or a hydrogen group. Yes, functional group-R ₁₀
Is a methyl group, an ethyl group, a phenyl group or a hydrogen group, and a pattern forming method. Embedded image 11. The acid dianhydride according to claim 1, wherein the acid dianhydride has a structure represented by the following chemical structural formula, and the functional group —R ₁₁ is a methyl group, an ethyl group, a phenyl group, or a hydrogen group. Any of the functional groups -R
_12. A pattern forming method, wherein ₁₂ is any one of a methyl group, an ethyl group, a phenyl group and a hydrogen group. [Chemical 4] 12. The diamine according to any one of claims 1 to 7, wherein the diamine has a structure represented by the following chemical structural formula, and the functional group —R ₁ contains a methyl group, an ethyl group, a phenyl group, a hydrogen group or silicon. The functional group -R ₂ is any one of a methyl group, an ethyl group, a phenyl group, a hydrogen group or a group containing silicon, and the functional group -R ₃ is a methyl group, an ethyl group or Either a phenyl group, a hydrogen group or a group containing silicon,
A pattern forming method, wherein the functional group -R ₄ is any one of a methyl group, an ethyl group, a phenyl group, a hydrogen group and a group containing silicon. Embedded image 13. The acid dianhydride according to any one of claims 1 to 7, wherein the acid dianhydride has a structure represented by the following chemical structural formula, and the functional group —R ₅ is a methyl group, an ethyl group, a phenyl group, a hydrogen group or silicon. And the functional group -R ₆ is any one of a methyl group, an ethyl group, a phenyl group, a hydrogen group or a group containing silicon, and the functional group -R ₇ is a methyl group or It is any one of an ethyl group, a phenyl group, a hydrogen group or a silicon-containing group, and the functional group -R ₈ is any of a methyl group, an ethyl group, a phenyl group, a hydrogen group or a silicon-containing group. A pattern forming method characterized by the above. [Chemical 6] 14. The diamine according to claim 1, wherein the diamine has a structure represented by the following chemical structural formula, and the functional group —R ₉ contains a methyl group, an ethyl group, a phenyl group, a hydrogen group or silicon. A method for forming a pattern, wherein the functional group -R ₁₀ is any one of a methyl group, an ethyl group, a phenyl group, a hydrogen group or a group containing silicon. [Chemical 7] 15. The acid dianhydride according to claim 1, having a structure represented by the following chemical structural formula, and the functional group —R ₁₁ is a methyl group, an ethyl group, a phenyl group, a hydrogen group or silicon. And the functional group —R ₁₂ is any one of a methyl group, an ethyl group, a phenyl group, a hydrogen group, and a silicon-containing group. Embedded image 16. The method according to any one of claims 1 to 15,
A pattern forming method, which is a compound in which silicon is replaced by germanium.