JP2002014474A - Pattern forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pattern forming method by which a pattern of a film to be worked with a good worked shape can be formed. SOLUTION: The pattern forming method has a step for forming an underlayer film 202 by coating the top of a film 201 to be worked with a solution for the underlayer film prepared by dissolving a novolak compound obtained by dehydration condensation of a naphthol derivative and formaldehyde or a novolak compound obtained by dehydration condensation of an anthracene derivative and formaldehyde in a solvent, a step for forming a resist film 203 on the underlayer film 202, a step for forming a resist pattern 204 by patternwise exposing the resist film 203, a step for forming a pattern 205 of the underlayer film by transferring the resist pattern 204 to the underlayer film 202 and a step for forming a pattern 206 of the film to be worked by transferring the pattern 205 to the film 201 to be worked.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pattern forming method in a semiconductor device manufacturing process.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process,
The method includes many steps of depositing a plurality of substances as a film to be processed on a silicon wafer and patterning the same into a desired pattern. In patterning the film to be processed,
First, a photosensitive material generally called a resist is deposited on a film to be processed to form a resist film, and a predetermined region of the resist film is exposed. Next, the exposed portion or the unexposed portion of the resist film is removed by a development process to form a resist pattern, and the film to be processed is dry-etched using the resist pattern as an etching mask.

In such a process, KrF, ArF is used as an exposure light source for exposing a resist film.
Ultraviolet light such as excimer laser is used.
With the miniaturization of I, if the required resolution is below the wavelength,
Exposure process latitude such as exposure latitude and focus latitude is becoming insufficient. To compensate for these process margins, it is effective to improve the resolution by reducing the thickness of the resist film, but on the other hand, the resist film thickness required for etching the film to be processed cannot be secured. The problem arises.

In order to solve this problem, a process for forming a lower layer film on a film to be processed, temporarily transferring a resist pattern to the lower layer film, and then transferring the resist pattern to the film to be processed using the lower layer film pattern as an etching mask. Considerations are being made.
In such a process, a material having etching resistance is preferable for the lower layer film. Conventionally, a resin containing a benzene ring, which is known to absorb energy during etching and has etching resistance, has been used.

[0005]

SUMMARY OF THE INVENTION However, A
When pattern exposure is performed using an rF excimer laser, the extinction coefficient of the benzene ring in the underlayer film is too large,
There is a problem that the reflection of the exposure light is rather high.

[0006] The present invention has been made in view of the above circumstances,
An object of the present invention is to provide a pattern forming method capable of forming a film pattern to be processed having a good processing shape by using a lower layer film that effectively suppresses reflection in an rF excimer laser wavelength region and has etching resistance. And

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention was prepared by dissolving a novolak compound obtained by dehydrating and condensing a naphthol derivative and formaldehyde or a novolak compound obtained by dehydrating and condensing an anthracene derivative and formaldehyde in a solvent. Forming a lower layer film by applying a lower layer film solution on a film to be processed, forming a resist film on the lower film, and forming a resist pattern by performing pattern exposure on the resist film Transferring the resist pattern to the lower film to form a lower film pattern, and transferring the lower film pattern to the film to be processed to form a film pattern to be processed. And a pattern forming method.

In the method of the present invention, a compound represented by the following formula (1) can be used as a naphthol derivative.

[0009]

Embedded image (Wherein, R _{1 to} R ₈ represent a hydrogen atom, a hydroxyl group, an alkylene group having 1 to 6 carbon atoms, or a hydroxyalkyl group having 1 to 6 carbon atoms)

[0010] As the anthracene derivative, a compound represented by the following formula (2) can be used.

[0011]

Embedded image (Wherein, R _{1 to} R ₁₀ represent a hydrogen atom, a hydroxyl group, an alkylene group having 1 to 6 carbon atoms, or a hydroxyalkyl group having 1 to 6 carbon atoms)

In the method of the present invention, the novolak compounds constituting the underlayer film solution are represented by the following formulas (3) to (9).
And a naphthol novolak represented by

[0013]

Embedded image

[0014]

Embedded image

[0015]

Embedded image _(Wherein, R 20 _{to R 29} represents a substituent containing a hydrogen atom or a hydroxyl _{group, R 3 0} is an alkylene group having 1 to 6 carbon atoms, n represents a positive integer.)

The novolak compound used in the present invention preferably has an average molecular weight of 500 to 200,000. Further, the step of forming the lower layer film pattern includes O ₂ ,
Dry etching using a source gas containing at least one selected from the group consisting of N ₂ , CO, and CO ₂ can be performed.

As described above, the present invention is characterized by using a lower film containing a polycyclic aromatic compound. Since the polycyclic aromatic compound does not have a too high k value at a wavelength of 193 nm, the deviation of the complex refractive index from the resist is small. As a result, there is an advantage that reflected light of exposure light to the resist can be suitably suppressed. Further, since the lower film contains a polycyclic aromatic compound, the lower film suitably acts as an etching mask when etching the film to be processed,
It is possible to process the film to be processed with good dimensional controllability.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.

First, as shown in FIG. 1A, a lower film 1 is formed on a film 101 to be processed formed on a wafer substrate 100.
02 is formed. The film to be processed 101 is not particularly limited. For example, an organic material such as polymethacrylate, polyarylene, polyarylene ether, carbon, or an insulating film such as silicon oxide, silicon nitride, silicon oxynitride, or polysiloxane And silicon-based materials such as amorphous silicon, polysilicon, and silicon substrates; and metal materials such as aluminum, aluminum silicide, tungsten, tungsten silicide, copper, and titanium nitride.

The thickness of the lower film 102 is 20 to 5000 nm.
Is preferably within the range. The reason is that the film thickness is 20
If the thickness is smaller than or equal to nm, the lower film 102 will not be removed during the etching of the film 101 to be processed, and
Is difficult to process in a desired size. On the other hand, when the film thickness is more than 5000 nm, when the resist pattern is transferred to the lower film 102 by the dry etching method,
This is because a dimensional conversion difference easily occurs.

The extinction coefficient k at the exposure wavelength of the lower film 102 is preferably in the range of 0.02 ≦ k ≦ 0.5, more preferably 0.05 ≦ k ≦ 0.4, If it is less than 0.02, the absorption is too low and the antireflection ability is reduced. If it exceeds 0.5, the absorption becomes too high and the reflection becomes high.

The lower layer 102 is preferably formed by a coating method. The reason is that the application method has a simpler process than the CVD method, and the process cost can be reduced.

Here, a method of forming the lower layer film 102 by a coating method will be described in detail. First, a lower layer film solution is prepared by dissolving a novolak compound obtained by dehydrating and condensing a naphthol derivative and formaldehyde or a novolak compound obtained by dehydrating and condensing an anthracene derivative and formaldehyde in a solvent.

The naphthol derivative may be a compound represented by the above formula (1), and the anthracene derivative may be a compound represented by the above formula (2).

Examples of such a novolak compound include resins represented by the above formulas (3) to (9). Here, in the above equations (3) to (9),
R _{2 1} to R ₂₉ represents a substituent containing a hydrogen atom or a hydroxyl _{group, R 30} is an alkylene group having 1 to 6 carbon _atoms, R 21 _{to R 29} is an alkyl group having 1 to 6 carbon atoms Is preferable, because the solubility of the resin in the solvent is increased, and the coating property is improved. Further, R _{21 to} R ₂₉ are preferably an alkylene group having 1 to 6 carbon atoms, because a hydroxyl group in the hydroxyalkyl group is crosslinked at the stage of baking after coating.

The molecular weight of the resin represented by the formulas (3) to (9) is not particularly limited, but is preferably 500 to 20.
000 is preferred. The reason is that if the molecular weight is less than 500, the underlayer film is dissolved in the solvent of the resist, while if it exceeds 200,000, it is difficult to dissolve in the solvent,
This is because it becomes difficult to prepare a solution material.

In order to improve the storage stability as required, a thermal polymerization inhibitor, an adhesion enhancer for improving the adhesion to the film to be processed, a conductive substance, and an electric conductivity by light and heat. A surfactant may be added to improve the resulting substance and coatability. When the above additive is added, it is preferable that the resin is contained in an amount of 70 parts by weight or more, when the solid content of the lower layer film is 100 parts by weight.

The solvent for dissolving the resin is not particularly limited. For example, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, and cellosolves such as methyl cellosolve, methyl cellosolve acetate and ethyl cellosolve acetate. Examples thereof include system solvents, ester solvents such as ethyl lactate, ethyl acetate, butyl acetate, and isoamyl acetate; alcohol solvents such as methanol, ethanol, and isopropanyl; and anisole, toluene, xylene, naphtha, and water.

The underlayer film solution is prepared by the above-described method, applied to the film to be processed 101 by, for example, a spin coating method, and then heated to evaporate the solvent to thereby form the underlayer film 10.
2 can be formed.

Next, as shown in FIG. 1B, an intermediate film 103 is formed on the lower film 102 as required. The intermediate film 103 is not particularly limited, but an inorganic oxide can be preferably used. Examples of the inorganic oxide include titanium oxide, alumina oxide, and tungsten oxide. Polysiloxane can also be used for the intermediate film 103.

The method of forming the intermediate film 103 is preferably a coating method. The reason is that the coating method has a simple process and can keep the process cost low as compared with the CVD method. The thickness of the intermediate film 103 is 10 to 3000 nm.
The reason is that, when the thickness of the intermediate film 103 is less than 10 nm, the intermediate film 103 is not removed during the etching of the lower film 102, and when the thickness exceeds 3000 nm, the resist pattern is transferred to the intermediate film 103. To
This is because a processing conversion difference occurs remarkably.

Next, as shown in FIG.
A resist solution is applied on the substrate 03 and heat-treated to form a resist film 104. If the thickness of the resist film 104 is reduced, the exposure latitude, the focus latitude, or the resolution can be improved. Therefore, the thickness of the resist film 104 is preferably small as long as the intermediate film 103 can be etched with good dimensional control.
The range of 10 to 10000 nm is preferred.

The type of the resist is not particularly limited, and a positive type or a negative type can be selected and used according to the purpose. Specifically, as the positive resist, for example, a resist (IX-770, manufactured by Nippon Synthetic Rubber Co., Ltd.) composed of naphthoquinonediazide and a novolak resin, a polyvinylphenol resin protected with t-BOC, and an acid generator Amplified Resist (APEX)
-E, manufactured by Shipley Co., Ltd.).

As the negative resist, for example, a chemically amplified resist (SNR200, manufactured by Shipley Co., Ltd.) comprising polyvinyl phenol, a melamine resin and a photoacid generator, and a resist (RD-RD) comprising polyvinyl phenol and a bisazide compound 2000N, manufactured by Hitachi Chemical Co., Ltd.), but are not limited thereto.

These resist solutions are applied onto the intermediate film 103 by, for example, a spin coating method or a dipping method, and then heated to evaporate the solvent, thereby forming the resist film 1.
04 is created. Then, the resist film is subjected to pattern exposure and developed to form a resist pattern 105 as shown in FIG.

Regarding the exposure light source, the g-line (43
6 nm), i-line (365 nm), or XeF (wavelength = 3
51 nm), XeCl (wavelength = 308 nm), KrF
(Wavelength = 248 nm), KrCl (wavelength = 222 n)
m), ArF (wavelength = 193 nm), F ₂ (wavelength = 15
7 nm).

The underlayer film used in the method of the present invention suitably acts as an anti-reflection film when ultraviolet light is used as an exposure light source.
It is also possible to use an ion beam or the like. After the exposure is completed, post-exposure baking is performed as necessary, and then development processing is performed with an alkali developing solution such as TMAH or choline to form a resist pattern 105.

Next, as shown in FIG. 2E, the resist film pattern 105 is transferred to the intermediate film 103 by using a dry etching method, and an intermediate film pattern 106 is formed. Examples of the etching method include reactive ion etching, magnetron type reactive ion etching, electron beam ion etching, ICP etching, and E etching.
There is no particular limitation as long as it can be finely processed, such as CR ion etching.

Thereafter, as shown in FIG. 2F, the intermediate film pattern 106 is formed by using the dry etching method.
02 to form a lower layer film pattern 107. As the etching method, the same method as used when the intermediate film 103 is etched can be used. Although the source gas is not particularly limited, for example, O ₂ , C
Gases containing oxygen atoms such as O and CO ₂ , He, N ₂ , A
For example, an inert gas such as r, a chlorine-based gas such as Cl ₂ or BCl ₃ , H ₂ , and NH ₃ can be used.
These gases may be mixed and used.

Next, as shown in FIG. 2 (g), a lower layer film pattern 107 is formed by dry etching.
01 to form a film pattern 108 to be processed.
As an etching method, the same method as used when the intermediate film 103 is etched can be used. The source gas is not particularly limited, and high mask resistance can be obtained, so that the target film 101 can be processed with good anisotropy.

In the above embodiment, the case where the intermediate film 103 is interposed between the lower film 102 and the resist film 104 has been described. However, the resist film is formed directly on the lower film without the intermediate film. May be. The type of the resist is not particularly limited, but a resist containing an inorganic atom, particularly a silicon atom, can be suitably used in order to obtain an etching selectivity with respect to the underlying film. The thickness of the resist film, the method of forming the resist pattern, and the method of etching the lower layer film are the same as those in the case where the above-described intermediate layer is used.

[0042]

EXAMPLES Hereinafter, various examples and comparative examples of the present invention will be shown, and the effects of the present invention will be described more specifically. Example 1 An example in which an SiO ₂ pattern is formed on a silicon wafer will be described with reference to FIGS. First, as shown in FIG.
A film to be processed is formed to a thickness of 500 n by an LPCVD method.
m SiO ₂ film 201 was formed.

Next, on the film 201 to be processed, the following (S
1) to (S4), the lower film 202 was formed. The thickness of the lower layer film 202 is 300 nm. Exposure wavelength 19 of each lower layer film 202 measured using a spectral ellipsometer
The measurement results of the complex refractive index at 3 nm are shown in Table 2 below.

(S1): A lower layer solution is prepared by dissolving 10 g of a novolak resin represented by the following formula (10-1) having an average weight molecular weight of 12,000 in 90 g of ethyl lactate, and then using a spin coating method. After coating on the film 201 to be processed, baking was performed at 250 ° C. for 2 minutes to form a lower layer film 202.

(S2): An underlayer film solution prepared by dissolving 10 g of a novolak resin represented by the following formula (10-2) having an average weight molecular weight of 10,000 in 90 g of ethyl lactate in (S1).

(S3): An underlayer film solution prepared by dissolving 10 g of a phenolic resin represented by the following formula (10-3) having an average weight molecular weight of 11,000 in 90 g of ethyl lactate in (S1).

(S4): An underlayer film solution prepared by dissolving 10 g of a phenolic resin represented by the following formula (10-4) having an average weight molecular weight of 8,000 in 90 g of ethyl lactate in (S1) was used.

[0048]

Embedded image

Next, on the lower film 202, the following formula (11)
9 g of a dissolution inhibitor having an average weight molecular weight of 12,000 and an acid generator 1 represented by the following formula (12)
g was dissolved in 90 g of ethyl lactate, and the resist was applied by a spin coating method, and baked at 140 ° C. for 90 seconds using a hot plate to obtain a resist as shown in FIG.
As shown in FIG. 7, a resist film 203 having a thickness of 200 nm was formed.

[0050]

Embedded image

Further, using an ArF excimer laser,
After pattern exposure is performed on the resist film 203, 1
Baking was performed at 40 ° C. for 90 seconds. Then, 0.2
A developing process is performed using 1N tetrahydroxyammonium, and as shown in FIG.
A resist pattern 204 having an m contact hole pattern was formed. As a result, no wavy shape due to the standing wave was found on the side wall of the resist pattern 204 formed on any of the lower films 202.

The light intensity reflectance at the interface between the resist film 203 and the lower film 202 was calculated with respect to the thickness of the lower film 202. At that time, the complex refractive index at a wavelength of 193 nm of each layer used in the calculation is as shown in Table 1 below. The calculation results are shown in Table 2 below.

From Table 2 below, it can be seen that the reflectance is as low as 1.3% or less in any of the lower layers (S1, S2, S3 and S4) in this embodiment. Therefore, it can be considered that the reason why the wavy shape due to the standing wave was not observed on the side wall of the resist pattern was that the reflection of the exposure light from the lower film to the resist film could be sufficiently suppressed.

Next, as shown in FIG. 3D, the resist pattern 204 was transferred to the lower film 202 by using a dry etching method to form a lower film pattern 205.
As the etcher, a magnetron-type reactive ion etching apparatus was used, and N ₂ / O ₂ =
Etching was performed using 10/100 sccm under the conditions of a vacuum degree of 75 mT, an excitation density of 1.3 W / cm ² , and a substrate temperature of 40 ° C. As a result, any of the lower layers (S1, S
2, S3, and S4), processing could be performed with good anisotropy as shown in FIG.

Next, as shown in FIG. 3 (e), the lower layer film pattern 205 was transferred to the film 201 by dry etching to form a film pattern 206 to be processed. A magnetron-type reactive ion etching apparatus was used as an etcher, and CF ₄ / O was used as an etching gas.
₂ / Ar = 5/10/100 sccm, vacuum degree 7
Etching was performed under the conditions of 5 mT, an excitation density of 1.3 W / cm ² , and a substrate temperature of 40 ° C.

The film pattern to be processed 20 thus obtained
6 was measured. The results are shown in Table 2 below. From Table 2 below, the taper angle of the film pattern 206 to be processed is more than the allowable value of 87 ° when any of the lower layers (S1, S2, S3, S4) is used. It turns out that it is processed well.

The etching rates of the lower film and the film to be processed are examined, and the etching selectivity (=
Table 2 below shows the result of calculating (etch rate of the film to be processed / etch rate of the lower layer film). From Table 2 below, when any of the lower layer films (S1, S2, S3, S4) was used, a selectivity of about 9.2 or more was obtained, and a good processed shape of the film to be processed was obtained. This is probably because the etching resistance of the lower layer film was sufficiently high.

Comparative Example In this comparative example, a novolak resin containing one aromatic ring or a polyvinylphenol resin prepared by the following method (R1) or (R2) as the lower layer film in Example 1 was used. This is an example in the case of using a film made of.

(R1): 10 g of a novolak resin represented by the following formula (13-1) and having an average weight molecular weight of 11,000 was dissolved in 90 g of ethyl lactate.
A lower layer film was formed in the same manner as in 1).

(R2): A solution of 10 g of a polyvinylphenol resin having an average weight molecular weight of 12,000 represented by the following formula (13-2) dissolved in 90 g of ethyl lactate, and treated in the same manner as in (S1) of Example 1. To form a lower layer film.

[0061]

Embedded image

In the same manner as in Example 1, a SiO ₂ film was formed as a film to be processed on a silicon wafer. Then
On the film to be processed, by the method shown in the above (R1) and (R2),
A lower layer film was formed. The thickness of the lower layer film is 300 nm. Table 1 shows the measurement results of the complex refractive index of each underlayer film at an exposure wavelength of 193 nm measured using a spectral ellipsometer.
Shown in

Next, in the same manner as in Example 1, a resist pattern is formed, and this resist pattern is transferred to an underlayer film to form an underlayer film pattern. Then, the underlayer film pattern is transferred to a film to be processed and covered. A processed film pattern was formed. The results of measuring the taper angle of the film pattern to be processed are shown in Table 2 below.

From Table 2 below, it can be seen that any of the lower films (R1, R
Even when 2) was used, the allowable value was 87 ° or less, and the film to be processed could not be processed with good anisotropy. Table 2 below shows the result of calculating the etching selectivity with respect to the lower layer of the film to be processed. From Table 2 below, the etching selectivity is
It is lower than the lower layer film used in Example 1, and it is considered that the reason why a favorable processed shape of the film to be processed was not obtained was that the etching resistance of the lower layer film was not sufficient.

Embodiment 2 This embodiment is an embodiment in which the processing of the film to be processed is performed by the multilayer resist process using the intermediate film in the embodiment 1. This will be described with reference to FIGS.

First, as shown in FIG.
The film to be processed 1 is formed on the silicon wafer 100 in the same manner as
01, a lower film 102 was sequentially formed.

Next, an average weight molecular weight of 12,000,
10 g of a polysiloxane represented by the following formula (14)
Is dissolved in 90 g of isopropyl alcohol, and a solution material for the intermediate film prepared is applied on the lower film 102 by a spin coating method, and then 300 μm is applied using a hot plate.
Baking was performed at 90 ° C. for 90 seconds to form an intermediate film 103 as shown in FIG.

Next, a resist solution prepared by dissolving 9 g of a dissolution inhibitor represented by the following formula (15) having an average molecular weight of 11,000 and 1 g of an acid generator represented by the following formula (16) in ethyl lactate was prepared. After coating on the intermediate film 103 using a spin coating method, baking was performed at 140 ° C. for 90 seconds using a hot plate, and FIG.
As shown in (c), a resist film 104 was formed.

[0069]

Embedded image

Further, after pattern exposure is performed on the resist film 104 using an ArF excimer laser,
Baking was performed at 0 ° C. for 90 seconds. Subsequently, 0.21
A developing process is performed using a specified tetrahydroxyammonium, and as shown in FIG.
The resist pattern 105 having the contact hole pattern was formed.

Thereafter, the resist pattern 105 is transferred to the intermediate film 103 by using a dry etching method.
As shown in (e), an intermediate film pattern 106 was formed. As the etcher, a magnetron type reactive ion etching apparatus was used, and CF ₄ /
O ₂ / Ar = 10/10/100 sccm, vacuum degree 75 mT, excitation density 1.3 W / cm ² , substrate temperature 40
Etching was performed under the condition of ° C.

Next, the intermediate film pattern 106 is transferred to the lower film 102 by using a dry etching method.
As shown in (f), a lower film pattern 107 was formed. The etcher and the etching conditions used were the same as in the case of etching the lower layer film in Example 1. Observation of the processed shape of the lower layer film pattern 107 showed that it could be processed with good anisotropy as in Example 1.

Next, as shown in FIG. 2G, the lower film pattern 107 was transferred to the film 101 by dry etching to form a film pattern 108. The etcher and etching conditions used were the same as in the case of etching the film to be processed in Example 1.

The results of measuring the taper angle of the film pattern to be processed 108 thus formed are shown in Table 2 below.
From Table 2 below, it can be seen that, regardless of the use of any of the lower layer films, processing was performed with good anisotropy at an allowable value of 87 ° or less. This is presumably because the lower layer film used in this example has high etching resistance.

[0075]

[Table 1]

[0076]

[Table 2]

[0077]

As described in detail above, according to the present invention, the novolak resin is used as the lower layer film, so that the reflected light of the exposure light to the resist can be suitably suppressed, and When the film is etched, the lower layer film suitably acts as an etching mask, and the film to be processed can be processed with good dimensional control.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a pattern forming process according to an embodiment of the present invention in the order of steps.

FIG. 2 is a sectional view showing a pattern forming process according to an embodiment of the present invention in the order of steps.

FIG. 3 is a cross-sectional view showing a pattern forming process according to another embodiment of the present invention in the order of steps.

[Explanation of symbols]

 100, 200 substrate 101, 201 film 102, 202 lower film 103 intermediate film 104, 203 resist film 105, 204 resist pattern 106 intermediate film pattern 107, 205 lower film pattern 108, 206 Processed film pattern

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H01L 21/302 HF term (Reference) 2H025 AA02 AA03 AA09 AB16 AC04 AC08 AD01 AD03 DA34 FA41 2H096 AA25 CA05 EA05 HA23 5F004 AA04 BA13 CA03 CA04 DA01 DA23 DA25 DA26 DB26 EA02 EA28 5F046 CA04 CA07 PA07

Claims (6)

[Claims] An underlayer film solution prepared by dissolving a novolak compound obtained by dehydrating and condensing a naphthol derivative and formaldehyde or a novolak compound obtained by dehydrating and condensing an anthracene derivative and formaldehyde in a solvent is applied to a film to be processed to form an underlayer film. Forming, forming a resist film on the underlayer film, performing pattern exposure on the resist film to form a resist pattern, and transferring the resist pattern to the underlayer film to form an underlayer film A pattern forming method, comprising: forming a pattern; and transferring the lower layer film pattern to the film to be processed to form a film pattern to be processed. 2. The pattern forming method according to claim 1, wherein a compound represented by the following formula (1) is used as the naphthol derivative. Embedded image (Wherein, R _{1 to} R ₈ represent a hydrogen atom, a hydroxyl group, an alkylene group having 1 to 6 carbon atoms, or a hydroxyalkyl group having 1 to 6 carbon atoms) 3. The pattern forming method according to claim 1, wherein a compound represented by the following formula (2) is used as the anthracene derivative. Embedded image (Wherein, R _{1 to} R ₁₀ represent a hydrogen atom, a hydroxyl group, an alkylene group having 1 to 6 carbon atoms, or a hydroxyalkyl group having 1 to 6 carbon atoms) 4. The novolak compound according to the following formula (3):
The pattern forming method according to claim 1, wherein the naphthol novolak is represented by (9). Embedded image Embedded image Embedded image _(Wherein, R 20 _{to R 29} represents a substituent containing a hydrogen atom or a hydroxyl _{group, R 3 0} is an alkylene group having 1 to 6 carbon atoms, n represents a positive integer.) 5. The novolak compound has an average molecular weight of 5
2. The method according to claim 1, wherein the number is from 00 to 200,000.
4. The pattern forming method according to 1. 6. The step of forming the lower layer film pattern comprises the steps of
_2, N _2, CO, and a pattern forming method according to claim 1, characterized in that it is made by dry etching using a source gas containing at least one selected from the group consisting of CO _2.