JPH033239A - Etching method for polyimide resin film, wiring structure using the method, and processing method for material to be etched - Google Patents

Abstract

PURPOSE:To prevent deterioration in capacity and insulation property by the corrosion, etc., of a wiring conductor, caused by a denatured layer, so as to improve the reliability of an element by removing, with an organic solvent, the denatured layer which is created at the surface of a polyimide resin film, reacting with etching during etching. CONSTITUTION:In the method of forming a resist film pattern 3 at a polyimide resin film 2 formed on a substrate 1, and selectively etching the polyimide resin film in etchant with the resist film pattern 3 as a mask, the denatured film arising on the polyimide resin film by etchant is removed by an organic solvent. It is to be desired that this organic solvent should be selected from aprotic polar solvent and/or polyamide. To remove the organic solvent used in the surface treatment of the polyimide resin film, cleaning and/or heating is done. Hereby, partial weakening of the polyimide resin film, which is caused by the staying organic solvent, can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of etching a polyimide resin film, a wiring structure using the same, and a method of treating a material to be etched.

C. Prior Art] Polyimide resins have excellent heat resistance, moldability, mechanical properties, dimensional stability, etc., so they are used as insulators for wiring boards.
Preferably used.

Etching methods for polyimide resins can be roughly divided into dry etching using a gas such as oxygen or fluorine tetrachloride, and wet etching using a solvent.

Compared to wet etching, dry etching requires a larger apparatus and takes more time than wet etching because the gas is sealed in a vacuum state, and therefore is inferior in mass productivity. For this reason, wet etching is practically used.

Wet etching is conventionally known as, for example, Japanese Patent Application Laid-open No. 56-12.
As described in No. 5858 and No. 61-83235, a positive or negative resist film is formed on a polyimide resin film, and this is used as an etching mask using a basic etching solution. This is done by selectively etching the polyimide resin film.

At this time, the polyimide resin comes into contact with the etching solution and reacts with the etching solution to form an altered layer on the surface layer, and this altered layer is dissolved in the etching solution to proceed with etching.

[Problems to be Solved by the Invention] The above-mentioned altered layer is considered to be a low molecular weight polyimide resin produced as a result of decomposition and reaction of the polyimide resin by a strong basic solution, or a resin in which the imide ring has been cleaved. Such low molecular weight polyimide resins or resins with cleaved imide rings are always produced when immersed in a strong basic solution, and even after etching, an altered layer that is not removed remains.

However, if this deteriorated layer remains, the reliability of the polyimide resin film as an insulating film decreases.

In particular, when used as an interlayer insulating film of a multilayer wiring structure, when the upper layer wiring conductor of the wiring structure is formed on a polyimide resin film patterned by etching, the wiring conductor comes into contact with the deteriorated layer, and the wiring conductor It is easy to cause corrosion of the polyimide resin film and decrease reliability of the insulation properties of the polyimide resin film.
Decreases device reliability.

For this reason, it is insufficient for use in substrates where element reliability is desired, and is a fatal defect, particularly in thin-film multilayer substrates for large computers, etc., which have been developed in recent years.

SUMMARY OF THE INVENTION Accordingly, a first object of the present invention is to provide a method for etching a polyimide resin, which can remove the deteriorated layer remaining on the surface layer of the polyimide resin even after etching. A second object is to provide a method for treating a wiring structure and a material to be etched using the above method.

[Means for Solving the Problems] A first object of the present invention is to form a resist film pattern on a polyimide resin film formed on a substrate, and use the resist film pattern as a mask. In the method of selectively etching the polyimide resin film with an etching solution, the etching solution removes a deteriorated film formed on the polyimide resin film,
This is achieved by an etching method for a polyimide resin film, which is characterized in that it is removed using an organic solvent.

According to another aspect, the present invention includes forming a resist film pattern on an insulating film formed on a substrate, and etching the insulating film with a first etching solution using the resist film pattern as a mask. There is also provided a method of etching an insulating film, characterized in that the exposed portion of the insulating film is further treated with a second etching solution.

It is preferable that the second etching solution has selectivity to the altered layer on the exposed surface of the insulating film caused by contact in the first etching step.

Furthermore, a second object of the present invention is that the wiring structure of the present invention has a polyimide resin film etched by the above polyimide resin film etching method as an interlayer insulating film.
This is achieved by a stacked wiring structure.

According to another aspect, the wiring structure of the present invention includes an insulating film in which an opening is formed by etching, in which the previous Rnm film does not substantially contain a layer altered by etching. Provide a wiring structure.

The method of treating a material to be etched according to the present invention can be generally used when the material to be etched forms a deteriorated layer on the exposed surface portion due to etching.

The organic solvent used in the present invention is not particularly limited as long as it can remove the altered layer, but it is preferably selected from aprotic polar solvents and/or polyamines.

Preferably used aprotic polar solvents include N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, N-acetyl-ε-caprolactam, 1,3-dimethyl- 2-imidazolidinone, 1,2-dimethoxyethane, 1,2-jethoxyethane, l-acetoxy-2-
Examples include methoxyethane, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and the like.

Moreover, examples of polyamines include ethylene diamine, xylene diamine, trimethylene diamine, hexamethylene diamine, and the like.

Among them, N-methyl-2-pyrrolidone, N.

N-dimethylacetamide, dimethylsulfoxide and ethylenediamine are preferred.

The organic solvent may be used alone or as a mixture of several types.

Examples of the processing method include immersion processing, dip processing, spray processing, and the like, which are well-known development processing methods for organic resists.

In the immersion treatment, the substrate on which the bonimide resin film has been etched is immersed in a treatment solution.

In dip processing, a processing liquid is placed on the substrate, and in spray processing, the processing liquid is sprayed onto the substrate.

These treatment methods may be used alone or in combination.

In the present invention, in order to remove the organic solvent used in the surface treatment of the polyimide resin film, it is preferable to perform cleaning and/or heating. For cleaning, alcohol such as methyl alcohol, ethyl alcohol, isopropyl alcohol, or water is used. Heating is performed at 200 to 450°C.

By removing the used organic solvent from the resin film in this manner, local weakening of the polyimide resin film caused by the remaining organic solvent can be prevented.

The treatment temperature is preferably in the range of 20° C. or higher and lower than the boiling point of the organic solvent. Furthermore, preferably 30°C or higher,
The temperature is 120°C or less. At temperatures below 20°C, the altered layer cannot be removed sufficiently. Moreover, if the boiling point is exceeded, the organic solvent will volatilize, making it unsuitable for the working environment.

The surface layer of the polyimide resin film may be treated after etching and before or after the resist, which is an etching mask, is peeled off.

However, it is generally preferable to incorporate this processing step after resist stripping.

This is because when the polyimide resin film comes into contact with the resist stripping liquid, liquid exchange occurs quickly on the surface of the deteriorated layer.
This is because the removal of the altered layer proceeds efficiently.

The wiring board referred to in the present invention may be either a single layer or a multilayer.

IR determines whether the altered layer has been substantially removed.

Detection means such as FT-IR can be used.

Before etching and after surface treatment, peak intensities showing C=○ and C-N bonds, which are unique to polyimide structures, and bonds other than imide bonds, such as C=C bonds in aromatic rings, or particularly strongly observed in altered layers, are observed. Judgment is made based on the change in intensity relative to the peak intensity of the -NH- bond. If the relative intensity value after surface treatment is 374 or more than the relative intensity value before etching, then it has been substantially removed.

Further, the dielectric breakdown voltage of the wiring board from which the altered layer has been substantially removed is 250 V/μm or more.

(Margin below) As an etching solution for polyimide resin films.

Basic solvents consisting of mixtures of hydrazine hydroxide and polyamines are preferred. Specific examples of the polyamine include ethylenediamine, xylenediamine, trimethylenediamine, and hexamethylenediamine, and ethylenediamine and xylenediamine are preferred because they are inexpensive.

The blending ratio is preferably 90 to 3% by volume of hydrazine hydroxide and the remainder is polyamine. If hydrazine hydroxide is more than 90% by volume, the polyimide resin film will swell and pattern deformation will easily occur.

Also, if it is less than 30% by volume, the etching speed will decrease,
Not suitable for work efficiency.

When performing etching using an etching solution with the above composition, the temperature of the solution should be 15°C to 60°C, preferably 25°C to 50°C. If the solution temperature is less than 15°C, the etching speed will drop significantly and the work efficiency will decrease. Moreover, if the temperature exceeds 60° C., pattern deformation tends to occur.

The resist film used in the present invention may be organic or inorganic. Any organic resist can be used as long as it has resistance to etching solutions for polyimide resin films. As a commercially available resist, it is 0DUR.

OMR-83,0NNR (Tokyo Ohka Co., Ltd.) and the like are known.

As a method for applying the organic resist onto the polyimide resin film, a spin coating method using a spinner, dipping, spraying, printing, or other means is used. A desired pattern can be easily formed using an organic resist using well-known photolithography.

Inorganic resist uses a metal material as an etching mask. Specifically, materials include aluminum, titanium, copper, copper-nickel alloy, chromium, tungsten, and molybdenum, but any material can be used as long as it is resistant to the etching solution of polyimide resin films. It is.

Films of these metal materials are formed by a vapor deposition method, a sputtering method, or the like.

Furthermore, a desired pattern of photoresist is formed by photolithography.

[Function] On the surface stone of polyimide resin etched with a basic etching agent, an altered layer consisting mainly of low molecular weight polyimide resin or resin with cleaved imide rings is formed.

In the present invention, an organic solvent dissolves this altered layer.

In this way, deterioration in performance due to corrosion of wiring conductors and the like and deterioration in insulation properties caused by the deteriorated layer are prevented, and the reliability of the element is improved.

As the organic solvent, at least one selected from aprotic polar solvents and/or polyamines is preferably used. These solvents can selectively remove the degraded layer without attacking the polyimide resin.

When a polyimide resin film treated with an organic solvent is washed and/or heated, a resin film in which no organic solvent remains can be obtained.

In this way, local weakening of the polyimide resin film due to residual organic solvent can be prevented.

If the treatment with an organic solvent is carried out under conditions of 20"C or higher and below the boiling point of the organic solvent, the degraded layer can be efficiently dissolved and removed. Also, the organic solvent does not volatilize, so a single working environment is preferable. .

[Example 1] After forming an AQ vapor-deposited film with a thickness of 2 μm as a lower electrode on a silicon wafer, a polyimide precursor varnish with the registered trademark PIQ manufactured by Hitachi Chemical Co., Ltd. was spin-coated thereon. , this substrate was heated at 200°C for 30 minutes, then at 400°C.
The mixture was heated for 60 minutes to obtain a polyimide film with a thickness of about 5.0 μm.

Next, the above substrate was immersed in an etching solution consisting of a 70:30 (volume %) mixed solution of hydrazine hydroxide and ethylene diamine (anhydrous) at 30°C, and the entire surface of the polyimide film was etched by about 2.2 μm, and then The polyimide film has a thickness of approximately 2.8 cm, including a degraded layer formed on the surface layer of the polyimide film by washing with pure water and reacting with the etching solution during etching.
A μm polyimide film was obtained.

The substrate was further diluted with N,N-dimethylacetamide at 100%
The polyimide film was immersed for 30 minutes at 0.degree. C. and then washed with pure water to remove a degraded layer that had formed on the surface of the polyimide film by reacting with the etching solution during etching. This results in a thickness of approximately 2.0 μm.
9 Next, on the polyimide film,
An AQ film was vacuum deposited as an upper electrode at room temperature without heating the substrate to form an AQ deposited film with a thickness of 3.5 μm.

100 test elements were manufactured by the above method, and the dielectric breakdown voltage was measured using these. As a result.

In more than 90% of the test elements, the polyimide film had a voltage of 300V/
It exhibited a breakdown voltage of μm or more.

Comparative Example Similar to Example 1, a polyimide precursor varnish of PIQ was spin-coated onto a silicon wafer forming an AQ-deposited lower electrode with a thickness of 2 μm, and the substrate was heated at 200°C for 30 minutes.
4.2 minutes, then heated at 400℃ for 60 minutes to a thickness of approx.
A μm polyimide film was obtained.

Next, the above substrate was immersed in an etching solution consisting of a 70:30 (volume %) mixture of hydrazine hydride and ethylene diamine (anhydrous) at 30"C, and the entire surface of the polyimide film was etched by about 2.2μ". Subsequently, the polyimide film was washed with pure water to obtain a polyimide film with a thickness of about 2.0 μm, including a degraded layer formed on the surface layer of the polyimide film by reaction with the etching solution during etching.

Next, an AQ film was vacuum-deposited as an upper electrode on the polyimide film at room temperature without heating the substrate to form an A, Q deposited film with a thickness of 3.5 μm.

100 test elements were manufactured by the above method, and the dielectric breakdown voltage was measured using these. As a result, 90% of the test element
% or more, the dielectric breakdown voltage of the polyimide film is 100V/
It showed only a value of less than μm.

Examples 2 to 4 The organic solvent used to remove the altered layer was N-methyl-2-pyrrolidone, an aprotic solvent, in Example 2, and dimethyl sulfoxide, an aprotic solvent, in Example 3. A test element was produced in the same manner as in Example 1.

In Example 4, ethylenediamine, which is a polyamine, was used as the organic solvent, and the substrate was immersed in ethylenediamine for 30 minutes.
The same procedure as in Example 1 was carried out except that the samples were immersed at ℃ for 30 minutes.
A test element was produced.

The dielectric breakdown voltage of the test elements produced in Examples 2 to 4 was measured in the same manner as in Example 1, and 90% or more of the test elements showed a breakdown voltage of 300 V/μm or more.

Example 5 After obtaining a polyimide film containing a degraded layer in the same manner as in Example 1, the substrate was immersed in ethylenediamine, which is a polyamine, for 30 minutes at 100° C. in the same manner as in Example 4. Subsequently, it was washed with pure water to remove the degraded layer.

Furthermore, this substrate was heated at 350° C. for 30 minutes to obtain a polyimide film with a thickness of about 2.0 μm.

Next, an AQ film was vacuum-deposited as an upper electrode on the polyimide film at room temperature without heating the substrate.

An An vapor deposited film having a thickness of 3.5 μm was formed.

100 test elements were formed by the above method, and dielectric breakdown voltage was measured using them. As a result, as in Example 1, more than 95% of the test elements showed that the polyimide film had a voltage of 300V.
It showed a breakdown voltage of /μn1 or more.

Example 6 As shown in FIG. 1(a), a polyimide pre-opening varnish with registered trademark PIQ manufactured by Hitachi Chemical Co., Ltd. was spin-coated on a silicon wafer substrate 1, and the substrate was heated at 200"C for 3
After heating for 0 minutes, a polyimide film with a thickness of 4 μm was obtained. This operation was repeated again and finally heated at 400° C. for 60 minutes to form a polyimide resin film 2 with a thickness of 8 μm.

Next, as shown in FIG. 1(b), the polyimide resin film 2
On top is a negative resist 0NNR- manufactured by Tokyo Ohka Kogyo Co., Ltd.
20 (viscosity: 140 centivoice) was applied by spin coating, and the substrate was prebaked at 100° C. for 30 minutes to form a resist film 3 with a thickness of 2 μm.

Next, as shown in FIG. 1(c), the substrate was tightly coated using a predetermined pattern-forming negative mask (not shown), and exposed using an exposure apparatus equipped with a 500 W high-pressure mercury lamp. Subsequently, development was performed using a special developer for 0NNR-20 manufactured by Tokyo Ohka Kogyo Co., Ltd., the unexposed areas were removed, the product was rinsed using a special rinse solution, and post-baking was performed at 150°C for 30 minutes to form a 50 μm wide film. A punching pattern 3a was obtained.

Next, as shown in FIG. 1(d), the resist pattern 3
Using a as an etching mask, the polyimide resin film 2 was selectively etched away with an etching solution, and then washed with pure water. The etching conditions at this time were immersion in a 70:30 (volume %) mixed solution of hydrazine hydroxide and ethylene diamine (anhydrous) at 30 DEG C. for 50 minutes.

Next, as shown in FIG. 1(e), the above substrate was coated with 502 (trade name) (resist stripping liquid) manufactured by Tokyo Ohka Kogyo Co., Ltd. for 100 min.
After soaking at ℃ for 10 minutes, rinse.

Resist 3 was peeled off.

Next, the above substrate was coated with an aprotic polar solvent such as N, N-
immersed in dimethylacetamide at 100°C for 30 minutes,
Subsequently, the film was washed with pure water to remove the degraded layer that had formed on the surface layer of the polyimide resin film by reacting with the etching solution during etching, thereby obtaining a polyimide resin film with improved reliability.

Using the above method, 100 wiring boards were manufactured and used to produce #! The A-edge breakdown voltage was measured. As a result, 90% or more of the wiring boards exhibited a breakdown voltage of 300 V/μ or more.

Examples 7 to 9 Examples 7 to 9 used the aprotic polar solvent N-methyl-2-pyrrolidone as the solvent for removing the degraded film, and Example 8 used the same type of dimethyl sulfoxide. ,
A wiring board was manufactured in the same manner as in Example 6.

In Example 9, a wiring board was manufactured in the same manner as in Example 6, except that ethylenediamine, which is a polyamine, was used as the organic solvent, and the wiring board was immersed in ethylenediamine at 30° C. for 40 minutes.

The dielectric breakdown voltages of the wiring boards manufactured in Examples 7 to 9 were measured in the same manner as in Example 6, and the same results as in Example 6 were obtained.

Example 10 As shown in FIG. 2(a), a polyimide premortal varnish with registered trademark PIQ manufactured by Hitachi Chemical Co., Ltd. was spin-coated on a silicon wafer substrate 1, and the substrate was heated at 200°C for 30 minutes.
The mixture was heated for a minute to obtain a polyimide film with a thickness of 4 μm. This operation was repeated again and finally heated at 400° C. for 60 minutes to form a polyimide resin film 2 with a thickness of 8 μm. On top of that, by sputtering on the polyimide resin film 2,
An aluminum film 4 having a thickness of 0.8 μm was formed.

Next, as shown in FIG. 2(b), as a pretreatment for forming an etching mask made of an aluminum film.

OMR-83 (a negative type resist) manufactured by Tokyo Ohka Kogyo Co., Ltd. is spin-coated as a photoresist on the aluminum film 4, and prebaked at 85°C for 30 minutes to form a resist film 5 with a thickness of 1.5 μm. Formed.

Next, as shown in FIG. 2(c), a punched pattern 5a of 50μ11@ was obtained by a well-known photolithography technique using a predetermined pattern-forming negative mask (not shown).

Next, as shown in FIG. 2(d), using the pattern 5a of the photoresist film as a mask, an aluminum film 4 is formed.
The pattern 5a of the photoresist film is transferred to the aluminum film 4 by etching.
I got a. Etching of the aluminum film 4 was carried out by immersing the substrate in an etching solution consisting of 70 volumes of phosphoric acid, 25 volumes of nitric acid, and 5 volumes of acetic acid, and selectively etching the exposed portions of the aluminum film 4.

Next, as shown in FIG. 2(e), the above substrate was coated with Tokyo Ohka Kogyo Co., Ltd.'s Il trade name 5o2 (resist stripping liquid).
It was immersed at 100° C. for 10 minutes, rinsed, and the resist film pattern 5a was peeled off.

Next, as shown in FIG. 2(f), the polyimide resin film 2 was selectively etched away using an etching solution using the aluminum film pattern 4a as an etching mask, and then washed with pure water. The etching conditions at this time are
Hydrazine Hitleride-Ethylenediamine (Anhydrous) 7
It was to be immersed in a 0:30 (volume %) mixed solution at 30° C. for 50 minutes.

Next, the above substrate was treated with N, N, which is an aprotic polar solvent.
- It was immersed in dimethylacetamide at 100° C. for 30 minutes, and then washed with pure water to remove the altered layer that had formed on the surface layer of the polyimide resin film by reacting with the etching solution during etching.

Next, as shown in FIG. 2(g), the substrate is immersed in the aluminum film etching solution described above to remove the aluminum film pattern 4a, and a highly reliable polyimide resin film from which the deteriorated layer has been removed is formed. Obtained.

100 wiring boards were manufactured using the above method, and the dielectric breakdown voltage was measured using these. As a result, 90% or more of the wiring boards exhibited a breakdown voltage of 300 V/μm or more.

Examples 12 to 14 The organic solvent for removing the degraded film was N-methyl-2-pyrrolidone, an aprotic polar solvent in Example 12, and N-methyl-2-pyrrolidone in Example 1.
In Example 3, a wiring board was manufactured in the same manner as in Example 11 except that the same type of dimethyl sulfoxide was used.

In Example 14, a wiring board was produced in the same manner as in Example 11, except that ethylenediamine, which is a polyamine, was used as the organic solvent and the wiring board was immersed in ethylenediamine at 30° C. for 40 minutes.

The dielectric breakdown voltages of the wiring boards manufactured in Examples 12 to 14 were measured in the same manner as in Example 11, and the same results as in Example 11 were obtained.

Example 15 First, in order to obtain electrical continuity between the upper and lower sides of the alumina substrate 6, as shown in FIG. An alumina substrate 6 having a conductor layer 7 was prepared.

On the above substrate, registered trademark PIQ manufactured by Hitachi Chemical Co., Ltd.
A polyimide preform varnish was applied by spin coating, and the substrate was heated at 200° C. for 30 minutes and then at 350° C. for 30 minutes to obtain a cured polyimide film with a thickness of 4 μm. Repeat this operation three times to form a polyimide resin film 2 with a thickness of 12 μm.
was formed.

Next, as shown in FIG. 3(b), a polyimide resin film pattern was obtained in which the upper part of the conductor layer 7 was an opening. The pattern forming conditions at this time were to form and pattern a resist film using the same materials and under the same conditions as in Example 6, and then to etch the polyimide resin film so that the upper part of the conductor layer 7 becomes an opening, and to pattern it. was formed. At this time, a 1:1 projection exposure apparatus was used to expose the resist film.

Furthermore, the same material as in Example 6 was used for the etching solution for the polyimide resin film.

Next, it was immersed in N,N-dimethylacetamide, an aprotic polar solvent, at 100°C for 60 minutes, and then washed with pure water. During etching, it reacted with the etching solution and formed on the surface layer of the polyimide resin film. By removing the generated degraded layer, a polyimide resin film pattern with improved reliability was obtained.

Next, as shown in FIG. 3(C), a thickness of 3.
A μm aluminum film is formed by sputtering,
Next, as a resist, product name 0 manufactured by Tokyo Ohka Kogyo Co., Ltd.
Resist pattern (
(not shown), and using this as a mask, etching is performed using an etching solution consisting of 75 volumes of phosphoric acid, 10 volumes of nitric acid, and 15 volumes of acetic acid as an aluminum etching solution. An aluminum wiring layer pattern 9 of No. 1 was formed.

Next, as shown in FIG. 3(d), a second polyimide resin film is formed using the same method as in the step of FIG. 3(b) above so that the upper part of the aluminum wiring layer becomes a selective opening. Pattern 2-2 was formed. Then, in order to obtain conduction with the lower conductor layer (first aluminum wiring layer pattern 9), the second aluminum wiring layer pattern is placed so that the wiring is located above the opening of the second polyimide resin film pattern. 9-2 was formed by the same method as above.

This process was repeated to create a thin film multilayer wiring board having four layers consisting of 9 to 9-4 as the aluminum wiring layer and four layers consisting of 2 to 2-4 as the polyimide resin film.

100 wiring boards were manufactured using the above method, and the dielectric breakdown voltage was measured using these. As a result, 90% or more of the wiring boards exhibited a breakdown voltage of 300 V/μm or more.

[Effects of the Invention] As described above, the present invention removes the altered layer that is generated on the surface of the polyimide resin film by reacting with the etching solution during etching.

In this way, performance deterioration due to corrosion of wiring conductors and deterioration of insulation properties caused by the deteriorated layer can be prevented, and the reliability of the element can be improved.

Therefore, if the present invention is applied to the etching process of an insulating film of a semiconductor element or a thin film multi-N substrate, a highly reliable insulating film can be formed.

[Brief explanation of drawings]

FIG. 1, FIG. 2, and FIG. 3 are cross-sectional views outlining the manufacturing process of a wiring board using the present invention. 1... Substrate, 2... Polyimide resin film, 3...
Resist, 3a... Resist pattern, 4... Aluminum film, 4a... Aluminum film pattern, 5.
...Resist, 5a...Resist pattern, 6...
Alumina substrate, 7...nickel layer, 8...tungsten layer, 9...aluminum wiring.

Claims (1)

[Claims] 1. A method in which a resist film pattern is formed on a polyimide resin film formed on a substrate, and the polyimide resin film is etched with an etching solution using the resist film pattern as a mask. A method for etching a polyimide resin film, comprising removing a degraded film formed on the polyimide resin film by the etching solution using an organic solvent. 2. The method for etching a polyimide resin film according to claim 1, wherein the organic solvent is at least one selected from aprotic polar solvents and/or polyamines. 3. The method of etching a polyimide resin film according to claim 1 or 2, wherein the polyimide resin film treated with the organic solvent is washed and/or heated. 4. The method of etching a polyimide resin film according to claim 1, 2 or 3, wherein the treatment with the organic solvent is carried out at a temperature of 20°C or higher and lower than the boiling point of the organic solvent. 5. A resist film pattern is formed on the insulating film formed on the substrate, and using the resist film pattern as a mask, the insulating film is etched with a first etching solution, and then further insulated with a second etching solution. A method of etching an insulating film, characterized by processing an exposed part of the film. 6. Etching of an insulating film according to claim 5, wherein the second etching solution has selectivity to the altered layer on the exposed surface of the insulating film caused by contact in the first etching step. Method. 7. A wiring structure in which a polyimide resin film etched by the polyimide resin film etching method according to claim 1, 2, 3 or 4 is laminated as an interlayer insulating film. 8. A wiring structure having an insulating film in which an opening is formed by etching, wherein the insulating film does not substantially contain a layer altered by etching. 9. A method for treating a material to be etched, characterized in that, in the etching step, a degraded layer formed on the exposed surface of the material to be etched is treated with an organic solvent that acts selectively on the degraded layer.