JP3504247B2 - Manufacturing method of semiconductor device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device in which the etching resistance of a mask pattern during etching is improved, and in particular, a mask pattern formed by processing a multilayer film is used. The present invention relates to a method for manufacturing a semiconductor device that processes a processed member.

[0002]

2. Description of the Related Art Conventionally, a method of manufacturing a semiconductor device includes many steps of depositing a plurality of substances as a film to be processed on a silicon wafer and patterning the plurality of substances into a desired pattern. . The patterning of the film to be processed is performed in the following steps. First, a photosensitive substance generally called a resist is deposited on a film to be processed to form a resist film on the film to be processed. Then, a predetermined region of this resist film is exposed. Next, the exposed part or the unexposed part of the resist film is removed by a developing process to form a resist pattern. Further, the film to be processed is dry-etched by using this resist pattern as an etching mask to pattern the film to be processed.

In order to provide the resolution, exposure dose latitude, or focus latitude required for the pattern exposure, it is necessary to reduce the thickness of the resist film. For this reason, it has become impossible to secure the required film thickness of the resist film in the process of etching the film to be processed. In order to solve such a problem, a method is used in which a mask material having etching resistance higher than that of a resist film is formed on a film to be processed, and the resist pattern is sequentially transferred to the mask material and the film to be processed.

Conventionally, a metal film such as aluminum and carbon have been used as the mask material.
The metal film such as aluminum and carbon can be formed by a dry method such as a CVD method, a sputtering method or a vapor deposition method. Further, as a material that can be formed into a film by a wet method such as spin coating, a material obtained by curing polysilane, novolac resin, polyhydroxystyrene, or the like at high temperature is used. These polysilanes, novolac resins, polyhydroxystyrene, etc.
It is a resin usually used for photoresists.

[0005]

However, among the materials used for these mask materials, the metal film and carbon to be formed by the dry method require a vacuum system for film formation, and therefore the film formation cost is low. Get higher Further, even in a material which can be formed by a wet method, it is difficult to peel off the remaining mask material pattern after the processing of the film to be processed, because polysilane contains an inorganic component.

Further, in the material used for the photoresist, which is obtained by baking and hardening the resin, side etching easily occurs during the etching of the mask material, and it is difficult to process the mask material pattern with high accuracy. If the processing accuracy of the mask material pattern is lowered by the side etching, the processing accuracy of the film to be processed is lowered. As a result, there arises a problem that the reliability of the semiconductor device during operation is significantly reduced. Then, as the miniaturization of semiconductor devices progresses, the influence of these problems becomes more and more significant.

As described above, the mask material which can be suitably used for manufacturing the semiconductor device has not yet been obtained.

Therefore, the present invention has been made in view of the above-mentioned problems, and even if the mask material is made thinner due to the miniaturization of the semiconductor device, the etching resistance as the mask material can be sufficiently ensured, and the workpiece can be processed. An object of the present invention is to provide a method for manufacturing a semiconductor device that can be processed with high accuracy.

[0009]

In order to achieve the above object, a method of manufacturing a semiconductor device according to an embodiment of the present invention is
After applying the solution on the work piece, dehydrogenation reaction or dehydrogenation
A step of forming a mask material having an aromatic ring and having a carbon atom content of 80 wt% or more by increasing the carbon content by a water condensation reaction ; and etching the mask material into a desired pattern to form the mask material. The method includes the steps of forming a pattern and etching the member to be processed using the mask material pattern as a mask.

[0010]

DETAILED DESCRIPTION OF THE INVENTION The present inventors have found that the carbon content is 80
The inventors have found that the amount of side etching can be significantly reduced by using a mask material of wt% or more, and have completed the present invention.

Each embodiment of the present invention will be described below with reference to the drawings. In the description, common parts are denoted by common reference symbols throughout the drawings.

[First Embodiment] First, a method of manufacturing a semiconductor device according to a first embodiment of the present invention will be described. In addition, in the first embodiment, a case will be described in which a multilayer film is processed to form a pattern on a member to be processed, and the member to be processed is etched using the pattern as a mask. Here, the member to be processed is used as a mask material in the process of forming a constituent element of a semiconductor device such as a pattern of a wiring layer or an electrode layer after being processed into a predetermined shape and size. And 1 (a) to 1 (f), 2 (a) to 2 (c), and other cross-sectional views show cross-sections in the direction perpendicular to the longitudinal direction of the wiring layer pattern and the mask pattern. Represent

First, as shown in FIG. 1A, a polycrystalline silicon film 103 is formed on a silicon substrate 101 with an insulating film 102 interposed therebetween by a CVD method (Chemical-Vapour-Deposition method).
To form. This polycrystalline silicon film 103 is used as a material for a gate wiring layer or a gate electrode. After that, a silicon nitride film 104, which is a member to be processed, is formed on the polycrystalline silicon film 103 with a film thickness of about 200 nm by low pressure CVD
Method (Low-Pressure CVD method). This silicon nitride film 104 is used as a mask material in a process of etching the polycrystalline silicon film 103 into a shape such as a gate wiring layer or a gate electrode layer in a later step.

Here, the silicon nitride film 104 is used as the member to be processed, but the member is not limited to the silicon nitride film and the following members may be used. For example, as a workpiece, a silicon oxide film, a silicon oxynitride film, a silicon-based insulating film such as spin-on glass, or a silicon-based material such as amorphous silicon, polysilicon, or a silicon substrate, aluminum, aluminum silicide, copper, tungsten, or the like. Wiring materials can be used. These films may be used as a single layer or as a laminated film of two or more layers. Although the film thickness of the work piece differs depending on the application, it is generally 20 to 10,000 nm
It is preferably in the range of. The reason is that if it is less than 20 nm, it is difficult to exert the action that the member to be processed has, and if it is more than 10000 nm, a dimensional conversion difference is remarkable when the mask material pattern on the member to be processed is transferred to this member to be processed. This is because it occurs in.

Next, the silicon nitride film 1 which is the member to be processed
As shown in FIGS. 1B to 1D, a multilayer film having a three-layer structure including a mask material 105, an intermediate layer 106, and a photoresist film 107 is formed on 04. The method for forming each layer constituting this multilayer film will be specifically described below. First, as shown in FIG. 1B, a mask material 105 is formed on a silicon nitride film 104 which is a member to be processed.
The film thickness of the mask material 105 is preferably in the range of 20 to 5000 nm. The reason is that when the film thickness is less than 20 nm, the mask material 10 is being etched during the etching of the workpiece 104.
No. 5 is scraped off, and it becomes difficult to process the workpiece 104 with a desired dimension, and the film thickness is 5000 n.
This is because if the thickness is thicker than m, a dimensional conversion difference significantly occurs when the resist pattern processed by the photoresist film 107 is transferred to the mask material 105.

The complex refractive index n and k values of the mask material 105 at the exposure wavelength are 1.0 ≦ n ≦ 2.5 and 0.
It is necessary to be in the range of 02 ≦ k ≦ 1.0, and more preferably in the range of 1.2 ≦ n ≦ 2.2 and 0.1 ≦ k ≦ 1.0. This is because if the n value is less than 1.0 or exceeds 2.5, the deviation from the refractive index of the resist becomes large, the reflection of exposure light during pattern exposure becomes large, and the dimensional controllability deteriorates. Also, k value is 0.02
If it is less than 1.0, the absorption is too low and the antireflection ability is lowered. On the contrary, if it exceeds 1.0, the absorption is too high and the antireflection ability is lowered.

The mask material 105 is preferably formed by a coating method. The reason is that, compared with the case of forming by the CVD method, the case of forming by the coating method has a simple process and the process cost can be kept low.

The method of forming the mask material 105 by the coating method will be described in detail below. First, after applying the mask material, the carbon content of the mask material is reduced to 8 by baking.
An aromatic compound having a concentration of 0 wt% or more is dissolved in a solvent to prepare a mask material solution. As such a compound as a mask material raw material, for example, polyarylene represented by the following formula (1) can be given. In addition, polycyclic aromatic hydrocarbons can also be preferably used, for example, a compound obtained by polymerizing a naphthalene derivative represented by the following formula (2) or an anthracene derivative represented by the following formula (3). Polymerized compounds can be mentioned. As these polymers, the naphthalene derivative or the anthracene derivative may be polymerized with formaldehyde. Examples of such a compound include compounds represented by the following formulas (4) to (10). . Further, petroleum-based or petroleum-based pitch can be used as the polycyclic aromatic hydrocarbon. The petroleum-based or petroleum-based pitch can be obtained by separating and refining the solvent-soluble components of aromatic and aliphatic hydrocarbons. Further, as other compounds, compounds represented by the following formulas (11) to (23) can be used. These aromatic compounds not only have a high carbon content and have etching resistance, but also have a good solubility in a solvent because they have an aromatic ring. Therefore, by applying the solution, it is possible to obtain a coating film having no defect and a uniform film thickness.

[0019]

[Chemical 1]

[0020]

[Chemical 2]

[0021]

[Chemical 3]

[0022]

[Chemical 4]

[0023]

[Chemical 5]

[0024]

[Chemical 6]

[0025]

[Chemical 7]

The average weight molecular weight of the aromatic compound is not particularly limited, but is preferably 1,000 to 100,000. When the average weight molecular weight is less than 1000, the compound is liable to volatilize during baking, and when it exceeds 100,000, the compound is difficult to dissolve in a solvent and it becomes difficult to form a coating film.

In the mask material solution, two or more kinds of the aromatic compounds may be mixed, or an aromatic compound and a compound other than the aromatic compound may be mixed. Further, a compound obtained by polymerizing an aromatic compound and a compound other than the aromatic compound may be used. Further, if necessary, a thermal polymerization inhibitor may be added to the mask material solution in order to ensure storage stability of the mask material solution. Also, the workpiece 1
In order to improve the adhesion of the mask material solution to 04, an adhesion improver may be added, and a conductive substance or
A substance that becomes conductive by light or heat, or a surfactant may be added to improve the coating property.

The solvent used for the mask material solution is not particularly limited, but is, for example, a ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, or methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate. , Etc., or ester solvents such as ethyl lactate, ethyl acetate, butyl acetate, isoamyl acetate, etc.
Alternatively, there may be mentioned alcohol solvents such as methanol, ethanol and isopropanol, as well as anisole, toluene, xylene, naphtha and water.

The mask material solution is prepared by the above method, and the mask material solution is applied onto the workpiece 104 by, for example, the spin coating method. Subsequently, the mask material solution is baked to evaporate the solvent, whereby the workpiece 1 is processed.
A mask material 105 is formed on 04. The baking temperature at this time is not particularly limited, but is 100 to 5
The range of 00 ° C is preferred. This is because if the temperature is lower than 100 ° C., the solvent is difficult to dry, and if the temperature exceeds 500 ° C., the workpiece 104 may deteriorate.

After the baking treatment, the carbon content of the obtained mask material 105 is 100 wt% based on the weight of the mask material.
Then, the carbon content is 80 wt% or more, preferably 9
It must be 0 wt% or more. The reason is that if the carbon content is less than 80 wt%, sufficient etching resistance cannot be obtained when processing the workpiece 104,
Moreover, it is difficult to suppress side etching when processing the mask material 105. In order to set the carbon content of the mask material 105 to 80 wt% or more, a mask material solution in which the carbon content of the mask material raw material is 80 wt% or more may be prepared in advance. The carbon content of the mask material 105 may be increased by reducing oxygen or hydrogen by a dehydrogenation reaction or dehydration condensation and relatively increasing the carbon content. Dehydrogenation of polycyclic aromatic hydrocarbons starts to progress by baking at a temperature of approximately 300 ° C. or higher. In addition, the compound having a hydroxyl group starts the dehydration condensation reaction by baking at a temperature of 200 ° C. or higher.

Next, a method of processing the mask material 105 formed on the member to be processed 104 to form a mask material pattern will be described. In the first embodiment, the method of forming the mask material pattern is not limited,
For example, the methods (1) to (4) described below can be used.

(1) As shown in FIG. 1C, an intermediate film 106 containing a semiconductor element or a metal element is formed on the mask material 105. For example, the following formulas (24) to (4)
Any one or more of the compounds described in 8) is dissolved in a solvent to prepare a solution of the intermediate film 106. This solution is applied onto the mask material 105 by using a coating method such as a spin coating method. Then, the solution applied on the mask material 105 is baked to evaporate the solvent and dry the compound. As a result, the intermediate film 106 is obtained on the mask material 105.

[0033]

[Chemical 8]

[0034]

[Chemical 9]

[0035]

[Chemical 10]

[0036]

[Chemical 11]

[0037]

[Chemical 12]

The thickness of the intermediate film 106 is not limited, but is preferably in the range of 10 to 1000 nm. If the thickness of the intermediate film 106 is less than 10 nm, it becomes difficult to process the mask material 105 with high accuracy. Film thickness 1000n
If it is thicker than m, when the resist pattern 107 formed on the intermediate film 106 is transferred to the intermediate film 106, the intermediate film 1
It becomes difficult to process 06 with high precision.

As the semiconductor element contained in the intermediate film 106,
Although not limited, examples thereof include Si and Ge. The metal element contained in the intermediate film 106 is not limited, but examples thereof include Al, W, and Ti.

Next, as shown in FIG. 1D, the intermediate film 1
A photoresist film 107 is formed on 06. First, a resist solution for forming the photoresist film 107 is formed on the intermediate film 106 by, for example, a spin coating method,
Alternatively, apply by a dip method or the like. Then, the resist solution is baked by using a hot plate or an oven to vaporize the solvent. As a result, the photoresist film 107 is obtained on the intermediate film 106.

The thickness of the photoresist film 107 is preferably as thin as possible, as long as it can etch the intermediate film 106 with good dimensional control.
0000 nm is desirable. This is because if the thickness of the photoresist film 107 is reduced, the exposure dose latitude during exposure, the focus latitude, and the resolution due to pattern exposure can be improved accordingly.

The type of resist solution for forming the photoresist film 107 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 type resist, for example, a resist (IX-770, manufactured by JSR) composed of naphthoquinonediazide and a novolac resin, or a polyvinylphenol resin and onium protected with t-butoxycarbonyl (t-BOC). A chemically amplified resist (APEX-E, manufactured by Shipley Co., Ltd.) containing a salt and the like can be mentioned. As the negative resist, for example, a chemically amplified resist (SNR200, manufactured by Shipley) composed of polyvinylphenol, a melamine resin and a photoacid generator, a resist composed of polyvinylphenol and a bisazide compound (RD-2000N, Hitachi). Kaseisha) and the like.

Next, pattern exposure is performed on the photoresist film 107 using an exposure mask on which a pattern is drawn. At this time, the exposure light used is not limited, and examples thereof include ultraviolet light, X-rays, electron beams, and ion beams. As the ultraviolet light, g-line (wavelength = 436 nm) or i-line (wavelength = 365 nm) of a mercury lamp can be used. Other exposure light is Xe
F (wavelength = 351 nm), XeCl (wavelength = 308 n
m), KrF (wavelength = 248 nm), KrCl (wavelength =
An excimer laser such as 222 nm), ArF (wavelength = 193 nm), or F ₂ (wavelength = 157 nm) can be used. Note that when an electron beam or an ion beam is used, the exposure mask does not necessarily have to be used.

Next, the photoresist film 107 is subjected to development processing by a wet development method using an alkali developing solution such as trimethylammonium hydroxide (TMAH) and choline, and as shown in FIG. 1
07 is formed.

Next, by using the resist pattern 107 as a mask, the intermediate film 106 is dry-etched, so that the resist pattern 107 is removed from the intermediate film 10.
Transfer to 6. As a result, as shown in FIG.
The intermediate film pattern 106 is obtained. The etching method used for the dry etching is, for example, reactive ion etching, magnetron type reactive ion etching, electron beam ion etching, ICP etching, or ECR.
There is no particular limitation as long as fine processing such as ion etching is possible.

Next, the intermediate film pattern 106 is transferred to the mask material 105 by etching the mask material 105 using the intermediate film pattern 106 as a mask. As a result, a mask material pattern 105 is obtained as shown in FIG. The etching method used at this time is not particularly limited as long as fine processing is possible, such as reactive ion etching, magnetron type reactive ion etching, electron beam ion etching, ICP etching, or ECR ion etching. Absent.

Mask material 1 in the first embodiment
No. 05 has a high etching resistance to radicals, and therefore side etching is difficult to enter. Therefore, the mask material pattern 105 can be processed with high accuracy. That is, as shown in FIG. 2A, when the size of the intermediate film pattern 106 is Y and the size of the mask material pattern 105 is V, the size difference (size of side etching) between the size Y and the size V can be reduced. .

(2) In the mask material pattern forming method here, an example of using a resist pattern formed on the mask material 105 by a known silylation method will be described.

First, the processed member 104 shown in FIG.
As shown in FIG. 3A, a mask material 105 is formed on the top.

Next, as shown in FIG.
As shown in (b), a photoresist film 1 containing a hydroxyl group
07 is formed. The photoresist film 107 is not particularly limited as long as it contains a hydroxyl group, but a material containing polyvinylphenol, novolac, methacrylate, or acrylate can be used.
Although the thickness of the photoresist film 107 is not limited, it is preferably in the range of 5 nm to 10000 nm. If the film thickness of the photoresist film 107 is less than 5 nm, it becomes difficult to transfer the resist pattern to the mask material 105 with good dimensional controllability. If the film thickness is more than 10000 nm, the photoresist film 107 is processed by dry development to form the resist pattern. Difficult to form.

Next, pattern exposure is performed on the photoresist film 107 using a method similar to the exposure method described in (1) above, and as shown in FIG. 3C, the exposed exposed portion is exposed. The hydroxyl group of 107A is condensed. Then, the photoresist film 107 is exposed to a vapor containing a silicon compound, for example, hexamethyldisilazane. As a result, silicon is introduced into the unexposed portion, and the silylated portion 107B
To form.

Further, the unexposed portion 1 into which silicon is introduced
Using 07B as a mask, the exposed portion 107A in which silicon is not introduced and the mask material 105 are etched (dry-developed) by using an etching gas containing oxygen.
As shown in (d), a mask material pattern 105 is formed. The etching method used at this time is not particularly limited as long as fine processing is possible, such as reactive ion etching, magnetron type reactive ion etching, electron beam ion etching, ICP etching, or ECR ion etching. Absent.

(3) In the mask material pattern forming method here, the mask material pattern is formed by the following method.

First, the workpiece 104 shown in FIG.
As shown in FIG. 4A, a mask material 105 is formed on the top.

Next, as shown in FIG.
As shown in (b), a photoresist film 1 containing a hydroxyl group
07 is formed. Subsequently, pattern exposure is performed on the photoresist film 107 using the exposure mask, and the pattern shown in FIG.
As shown in (c), a resist pattern 107 is formed. Although the thickness of the photoresist film 107 is not limited, it is preferably in the range of 5 nm to 10000 nm. If the film thickness of the photoresist film 107 is less than 5 nm, it becomes difficult to transfer the resist pattern 107 to the mask material 105 with good dimensional controllability, and if the film thickness is more than 10000 nm, the resolution during pattern exposure deteriorates.

Next, as shown in FIG. 4D, a silylated portion 107C is formed on the resist pattern 107 by a commonly used silylation method as described below. That is, the resist pattern 107 is exposed to vapor containing a silicon compound, for example, hexamethyldisilazane. As a result, silicon is introduced into the resist pattern 107 to obtain the silylated portion 107C on the resist pattern 107.

Next, using the resist pattern 107 having the silylated portion 107C as a mask, the mask material 105 is etched with an etching gas containing at least oxygen. As a result, as shown in FIG.
Transfer the resist pattern 107 to the mask material 105,
A mask material pattern 105 is formed. Since silicon is introduced into the resist pattern 107, the mask material 1
05 and the resist pattern 107, the mask material 105 can be processed while maintaining a high selection ratio. Thereby, the mask material pattern 105 can be formed with high accuracy. The etching method at this time is not particularly limited as long as fine processing is possible, such as reactive ion etching, magnetron type reactive ion etching, electron beam ion etching, ICP etching, or ECR ion etching. Absent.

(4) In the mask material pattern forming method here, the mask material pattern is formed by the following method.

First, the processed member 104 shown in FIG.
As shown in FIG. 5A, a mask material 105 is formed on the top.

Next, as shown in FIG.
As shown in (b), a photoresist film 107 containing a semiconductor element or a metal element is formed. The semiconductor element contained in the photoresist film 107 is, for example, silicon or germanium. The metal element contained in the photoresist film 107 is, for example, tungsten, aluminum, titanium or the like. The thickness of the photoresist film 107 is not limited, but is 5 nm to 10 nm.
The range of 000 nm is preferred. Photoresist film 107
When the film thickness is less than 5 nm, it becomes difficult to transfer the resist pattern 107 to the mask material 105 with good dimensional controllability, and when the film thickness is more than 10000 nm, the resolution during pattern exposure deteriorates. A known silicon-containing resist or the like can be used as such a resist material.

Next, pattern exposure is performed on the photoresist film 107 using the same method as the exposure method described in (1) above, and then development processing is performed by a wet method, as shown in FIG. ), The resist pattern 107
To form.

Next, using the resist pattern 107 as a mask, the mask material 105 is etched with an etching gas containing at least oxygen. As a result, as shown in FIG. 5D, the resist pattern 107 is transferred to the mask material 105 to form the mask material pattern 105. Since the semiconductor element or the metal element is introduced into the resist pattern 107, the mask material 105 can be processed while maintaining a high selectivity between the mask material 105 and the resist pattern 107. Thereby, the mask material pattern 105 can be formed with high accuracy.

Next, the workpiece (silicon nitride film) 104 is etched by using the mask material pattern 105 formed by any of the above-mentioned methods (1) to (4) as a mask. As a result, as shown in FIGS. 2B, 3E, 4F, and 5E, the mask material pattern 105 is transferred to the workpiece 104, and the workpiece pattern is formed. Form 104. The etching method at this time is not particularly limited as long as fine processing is possible, such as reactive ion etching, magnetron type reactive ion etching, electron beam ion etching, ICP etching, or ECR ion etching. Absent.

Mask material 1 in the first embodiment
Since 05 contains many carbon atoms that are difficult to be sputtered, the amount of receding of the mask material pattern 105 is small when the workpiece 104 is etched. Therefore, in the processing of the processed member pattern 104, the processed member 104 can be processed with high accuracy.

After the etching of the member 104 to be processed, if the ashing process which is usually used with a gas containing oxygen plasma is performed, the mask material pattern 105 remaining on the member 104 to be processed is easily ashed. Can be removed.

[Second Embodiment] In the second embodiment, a more detailed embodiment than the first embodiment will be described.

By the same method as in the first embodiment,
As shown in FIG. 1A, an insulating film 102, a polycrystalline silicon film 103, and a member to be processed (silicon nitride film) 104 are sequentially formed on a silicon substrate 101. Here, the material of each film used, the film thickness, the manufacturing conditions thereof and the like are the same as those in the first embodiment.

Next, by using each of the methods listed in (S1) to (R3) below, the process shown in FIG.
As shown in (b), the mask material 105 having a film thickness of 300 nm
To form.

(S1) In the above formula (1), R _{1 to} R ₇ ,
R ₉ and R ₁₀ are hydrogen atoms, and R ₈ is CH = CH ₂ , and 10 g of polyarylene having an average weight molecular weight of 12,000 is dissolved in 90 g of cyclohexanone to prepare a mask material solution. This solution is applied on the member to be processed 104 by using a spin coating method. After that, baking is performed at 180 ° C. for 60 seconds, and then baking is performed at 400 ° C. for 60 seconds. By such step baking,
A mask material 105 is formed on the workpiece 104.

(S2) A mask material solution is prepared by dissolving 10 g of the aromatic compound having the average weight molecular weight of 10,000 described in the above formula (23) in 90 g of cyclohexanone.
This solution is applied on the member to be processed 104 by using a spin coating method. After that, baking is performed at 180 ° C. for 60 seconds, and subsequently, baking is performed at 300 ° C. for 60 seconds. The mask material 105 is formed on the member 104 to be processed by such step baking.

(S3) In the above formula (10), R _{21 to} R _21
28 is a hydrogen atom, R ₂₉ is CH ₂ OH, R ₃₀ is CH ₂
Aromatic polycyclic compound having an average weight molecular weight of 10,000
g is dissolved in 90 g of cyclohexanone to prepare a mask material solution. Other manufacturing conditions are the same as those in (S2) above.

(S4) A mask material solution is prepared by dissolving 10 g of an aromatic polycyclic compound having an average weight molecular weight of 10,000 in formula (13) in 90 g of cyclohexanone. Other manufacturing conditions are the same as those in (S2) above.

(S5) A mask material solution is prepared by dissolving 10 g of the aromatic polycyclic compound having an average weight molecular weight of 10,000 in formula (14) in 90 g of cyclohexanone. Other manufacturing conditions are the same as those in (S2) above.

(R1) 10 g of polycaptonimide having an average weight molecular weight of 8,000 is dissolved in 90 g of ethyl lactate to prepare a mask material solution. This solution is applied on the member to be processed 104 by using a spin coating method. After that, baking is performed at 180 ° C. for 60 seconds, followed by 3
Bake at 00 ° C. for 60 seconds. The mask material 105 is formed on the member 104 to be processed by such step baking.

(R2) The same mask material solution as in (S2) above is applied to the workpiece 10 by spin coating.
Apply on top of 4. After that, baking is performed at 180 ° C. for 60 seconds, and then step baking is performed at 250 ° C. for 60 seconds. By such step baking,
A mask material 105 is formed on the workpiece 104.

(R3) 10 g of a novolak resin having an average weight molecular weight of 8,000 is dissolved in 90 g of ethyl lactate to prepare a mask material solution. For other manufacturing conditions, see (R
The same as 1). The above is the method of forming the mask material.

The above (S1) to (S5) and (R1)
Each of the mask materials was formed on the silicon substrate by the methods (1) to (R3), and the carbon content of these mask materials was measured by the elemental analysis method. The carbon content of each mask material is as shown in Table 1 below. Comparing the carbon contents of the mask materials formed by the method (S2) and the method (R2),
(S2) has a higher carbon content. This is because the carbon content of the mask material increases by baking the mask material solution at a high temperature. Thus, the carbon content of the mask material may be increased by causing dehydration condensation or dehydrogenation reaction by baking.

[0078]

[Table 1]

The elemental analysis method is performed by the following method.

First, CO ₂ , H ₂ O, and N ₂ generated by burning an aromatic hydrocarbon compound are detected by gas chromatography. Next, C (carbon) is quantified from the detected CO ₂ , and similarly, H ₂ O to H (hydrogen) and N ₂ to N (nitrogen) are quantified. The amount of O (oxygen) is, for example, the quantified C, H, or
And N are subtracted to identify. The elemental composition ratio of the aromatic hydrocarbon compound can also be obtained by using X-ray photoelectron spectroscopy (XPS), secondary mass ion analysis (SIMS), or the like.

Next, a solution is prepared by dissolving 10 g of spin-on glass having an average weight molecular weight of 2,000 described in the above formula (26) in 90 g of polyglycol monopropyl ether. This solution is applied on the mask material 105,
As shown in (c), a film thickness of 80 nm is formed on the mask material 105.
The intermediate film 106 is formed.

Next, a positive chemically amplified resist (trade name: AT111S) manufactured by JSR Corporation is applied on the intermediate film 106 by a spin coating method. After that, the applied resist is baked at 130 ° C. for 80 seconds to form a film having a thickness of 3 on the intermediate film 106 as shown in FIG.
A photoresist film 107 having a thickness of 00 nm is formed. next,
Pattern exposure is performed on the photoresist film 107 using an exposure apparatus with NA = 0.68 using an ArF excimer laser as a light source. Then, on the photoresist film 107, 13
Bake for 80 seconds at 0 ° C. Then 0.21
Development processing was performed using NMA TMAH developer, and FIG.
As shown in (e), a resist pattern 107 composed of a 110 nm line-and-space pattern is formed.

Next, using the reactive ion etching device, the intermediate film 106 is etched with an etching gas containing CF ₄ and O _2.
To etch. As a result, the resist pattern 107 is transferred to the intermediate film 106 as shown in FIG.
The intermediate film pattern 106 is formed.

Next, using a reactive ion etching apparatus, the mask material 105 is etched with an etching gas containing N ₂ and O _2.
To etch. As a result, as shown in FIG. 2A, the intermediate film pattern 106 is transferred to the mask material 105,
A mask material pattern 105 is formed. As described above, assuming that the dimension of the intermediate film pattern 106 is Y and the dimension of the mask material pattern 105 is V, the carbon content of the mask material pattern 105 and the side etching amount of the mask material pattern 105 (Y−V ) Is as shown in FIG. The higher the carbon content of the mask material is, the smaller the side etching amount is, and the carbon content is generally 80 wt% or more and the allowable value is 5 nm or less. From this, when the carbon content of the mask material is 80 wt% or more, the mask material pattern 1
It can be seen that the effect of reducing the side etching amount generated when processing No. 05 is large. It is considered that the higher the carbon content of the mask material, the higher the resistance to oxygen radicals and the smaller the side etching amount.

Next, using the reactive ion etching apparatus, the member 1 to be processed is etched with an etching gas containing CF ₄ and O _2.
Etch 04. As a result, the mask material pattern 105 is transferred to the workpiece 104, and the workpiece pattern (silicon nitride film pattern) 104 is formed as shown in FIG.

Here, as described above, the dimension of the mask material pattern 105 is V, the dimension of the member pattern 104 to be processed is W, and VW is the processing conversion difference. The relationship between the carbon content of the mask material pattern 105 and the processing conversion difference (V-W), which occurs in the etching process of the member to be processed, is as shown in FIG. Further, the relationship between the carbon content of the mask material pattern 105 and the etching rate of the mask material pattern 105 under the etching condition of the member to be processed is as shown in FIG. When the mask material pattern 105 having a high carbon content is used, the processing conversion difference is small, and the carbon content is about 80.
It is less than the allowable value of 5 nm at wt% or more. From this, the carbon content of the mask material pattern 105 is 80 wt%.
In the above cases, it can be seen that the effect of improving the etching resistance of the mask material pattern 105 is great. In particular, when the carbon content is 90 wt% or more, it can be seen that the processing conversion difference is small and the dimensional controllability is high.

After that, the mask material pattern 105 on the member pattern 104 to be processed is ashed and removed by using an ashing device.

Next, the reactive ion etching apparatus is used to etch the polycrystalline silicon film 103 as a conductive material with an etching gas containing at least Cl ₂ . As a result, as shown in FIG. 2C, the workpiece member pattern 1
04 is transferred to the polycrystalline silicon film 103 to form a polycrystalline silicon pattern 103. This polycrystalline silicon film 1
In the etching step of 03, since the polycrystalline silicon film 103 is processed using the processed member pattern 104 processed with high accuracy as a mask, the polycrystalline silicon pattern can be formed with high accuracy.

[Third Embodiment] In the third embodiment, a manufacturing method using a resist pattern 107 formed by the method (2) described in the first embodiment will be described.

In the same manner as in the first embodiment,
As shown in FIG. 1A, an insulating film 102, a polycrystalline silicon film 103, and a member to be processed (silicon nitride film) 104 are sequentially formed on a silicon substrate 101. Here, the material of each film used, the film thickness, the manufacturing conditions thereof and the like are the same as those in the first embodiment.

Next, in the second embodiment,
Using the methods listed in (S1) to (S5) and (R1) to (R3), respectively, on the member 104 to be processed, as shown in FIG.
As shown in (a), the mask material 105 having a film thickness of 300 nm is used.
To form.

Next, 10 g of polyvinylphenol having an average weight molecular weight of 12000 is dissolved in 90 g of ethyl lactate to prepare a resist solution. This resist solution is applied on the mask material 105 by spin coating. afterwards,
Baking is performed at 100 ° C. for 80 seconds, and as shown in FIG. 3B, the photoresist film 107 having a film thickness of 100 nm is formed.
To form.

Next, pattern exposure is performed by using an exposure apparatus with NA = 0.68 using an ArF excimer laser as a light source. As a result, the hydroxyl groups of the exposed portion 107A shown in FIG. 3C are condensed. Then, the photoresist film 107 is exposed to an atmosphere of hexamethyldisilazane having a vacuum degree of 10 mT. As a result, silicon is introduced into the hydroxyl groups in the unexposed portion of the photoresist film 107 to form the silylated portion 107B as shown in FIG.

Next, the exposed portion 107A of the photoresist film and the mask material 105 are etched by the same method as in the second embodiment. Thereby, as shown in FIG. 3D, the resist pattern 107B is transferred to the mask material to form the mask material pattern 105. here,
The dimension of the resist pattern 107B is Y, the dimension of the mask material pattern 105 is V, and the dimension difference between the dimension Y and the dimension V is the side etching amount (YV). Table 1 shows the measurement results of the side etching amount at this time. When the carbon content is 80 wt% or more, the side etching amount becomes 5 nm or less, which is the allowable value, as in the second embodiment,
The mask material pattern 105 can be processed with a small side etching amount.

Next, the member to be processed (silicon nitride film) 104 is etched by the same method as in the second embodiment, and the pattern 104 to be processed is formed as shown in FIG. 3 (e). Form. Here, the workpiece pattern 104
Is W, and the dimension V of the mask material pattern 105 is
And the dimension difference between the dimension W and the dimension W are defined as a machining conversion difference (V-W). When the carbon content is 80 wt% or more, the processing conversion difference is 5 nm or less, which is the allowable value, as in the second embodiment, and the workpiece member pattern 104 can be processed with high accuracy.

Further, the polycrystalline silicon film 103 is etched by the same method as that of the second embodiment, and the structure shown in FIG.
As shown in (f), the polycrystalline silicon film pattern 103
To form. In the etching process of the polycrystalline silicon film, the processed member pattern 104 processed with high precision is used.
Since the polycrystalline silicon film 103 is processed by using the mask as a mask, the polycrystalline silicon film pattern 1 is highly accurately processed.
03 can be processed.

[Fourth Embodiment] In the fourth embodiment, a manufacturing method using a resist pattern 107 formed by the method (3) described in the first embodiment will be described.

By the same method as in the first embodiment,
As shown in FIG. 1A, an insulating film 102, a polycrystalline silicon film 103, and a member to be processed (silicon nitride film) 104 are sequentially formed on a silicon substrate 101. Here, the material of each film used, the film thickness, the manufacturing conditions thereof and the like are the same as those in the first embodiment.

Next, in the second embodiment,
Using the methods listed in (S1) to (S5) and (R1) to (R3), respectively, on the member 104 to be processed, as shown in FIG.
As shown in (a), the mask material 105 having a film thickness of 300 nm is used.
To form.

Next, on the mask material 105, a positive chemically amplified resist (trade name AT111S) manufactured by JSR Corporation is used.
Is applied using a spin coating method. afterwards,
After baking at 100 ° C. for 80 seconds, as shown in FIG. 4B, a photoresist film 107 having a film thickness of 100 nm is formed.
To form.

Next, pattern exposure is performed using an exposure apparatus with NA = 0.68 using an ArF excimer laser as a light source, and baking is performed at 100 ° C. for 80 seconds. afterwards,
Develop with 0.21N TMAH developer.
As a result, as shown in FIG. 4C, the resist pattern 1 including the 130 nm line and space pattern is formed.
07 is formed.

Next, the resist pattern 107 is exposed to an atmosphere of hexamethyldisilazane having a vacuum degree of 10 mT.
As a result, silicon is introduced into the hydroxyl groups in the resist pattern 107 to form the silylated portion 107C as shown in FIG. 4 (d).

Then, the mask material 105 is etched to transfer the resist pattern 107C to the mask material by the same method as in the second embodiment, and as shown in FIG. Form 105. Here, the dimension of the resist pattern 107C is Y, the mask material pattern 1
The dimension of 05 is V, and the dimension difference between the dimension Y and the dimension V is the side etching amount (Y-V). Table 1 shows the measurement results of the side etching amount at this time. Carbon content 80
When it is set to be wt% or more, as in the second embodiment,
The side etching amount becomes 5 nm or less, which is an allowable value, and the mask material pattern 105 can be processed with a small side etching amount.

Then, the member to be processed (silicon nitride film) 104 is etched by the same method as in the second embodiment, and the member to be processed pattern 104 is formed as shown in FIG. 4 (f). Form. Here, the workpiece pattern 104
Is W, and the dimension V of the mask material pattern 105 is
And the dimension difference between the dimension W and the dimension W are defined as a machining conversion difference (V-W). When the carbon content is 80 wt% or more, the processing conversion difference is 5 nm or less, which is the allowable value, as in the second embodiment, and the workpiece member pattern 104 can be processed with high accuracy.

Further, the polycrystalline silicon film 103 is etched by the same method as in the second embodiment, and the structure shown in FIG.
As shown in (g), the polycrystalline silicon film pattern 103
To form. In the etching process of the polycrystalline silicon film, the processed member pattern 104 processed with high precision is used.
Since the polycrystalline silicon film 103 is processed by using the mask as a mask, the polycrystalline silicon film pattern 1 is highly accurately processed.
03 can be processed.

[Fifth Embodiment] In the fifth embodiment, a manufacturing method using a resist pattern 107 formed by the method (4) described in the first embodiment will be described.

According to the same method as in the first embodiment,
As shown in FIG. 1A, an insulating film 102, a polycrystalline silicon film 103, and a member to be processed (silicon nitride film) 104 are sequentially formed on a silicon substrate 101. Here, the material of each film used, the film thickness, the manufacturing conditions thereof and the like are the same as those in the first embodiment.

Next, in the second embodiment,
Using the methods listed in (S1) to (S5) and (R1) to (R3), respectively, on the member 104 to be processed, as shown in FIG.
As shown in (a), the mask material 105 having a film thickness of 300 nm is used.
To form.

Next, 9 g of an inhibitor resin containing silicon represented by the following formula (49) and having an average weight molecular weight of 12000,
1 g of sulfonimide as an acid generator in 80% ethyl lactate
Dissolve in g to prepare a solution. This solution is applied on the mask material using the spin coating method. Then 1
Baking is performed at 00 ° C. for 80 seconds to form a silicon-containing photoresist film 107 having a film thickness of 100 nm as shown in FIG.

[0110]

[Chemical 13]

Next, pattern exposure is carried out using an exposure apparatus with NA = 0.68 using an ArF excimer laser as a light source. Then, after baking at 100 ° C. for 80 seconds,
Develop with 0.21N TMAH developer,
As shown in FIG. 5C, a resist pattern 107 having a 130 nm line and space pattern is formed.

Then, the mask material 105 is etched to transfer the resist pattern 107 to the mask material by the same method as in the second embodiment, and as shown in FIG. Form 105. Here, the dimension of the resist pattern 107 is Y, the mask material pattern 10
The dimension 5 is V, and the dimension difference between the dimension Y and the dimension V is the side etching amount (Y-V). Table 1 shows the measurement results of the side etching amount at this time. 80w carbon content
When t% or more, as in the second embodiment, the side etching amount becomes 5 nm or less, which is an allowable value, and the mask material pattern 105 can be processed with a small side etching amount.

Then, the member to be processed (silicon nitride film) 104 is etched by the same method as that of the second embodiment to form the member pattern 104 to be processed as shown in FIG. 5 (e). Form. Here, the workpiece pattern 104
Is W, and the dimension V of the mask material pattern 105 is
And the dimension difference between the dimension W and the dimension W are defined as a machining conversion difference (V-W). When the carbon content is 80 wt% or more, the processing conversion difference is 5 nm or less, which is the allowable value, as in the second embodiment, and the workpiece member pattern 104 can be processed with high accuracy.

Further, the polycrystalline silicon film 103 is etched by the same method as that of the second embodiment, and the structure shown in FIG.
As shown in (f), the polycrystalline silicon film pattern 103
To form. In the etching process of the polycrystalline silicon film, the processed member pattern 104 processed with high precision is used.
Since the polycrystalline silicon film 103 is processed by using the mask as a mask, the polycrystalline silicon film pattern 1 is highly accurately processed.
03 can be processed.

[Sixth Embodiment] In the sixth embodiment, a method of forming a pattern using a multilayer film and using the pattern as a mask to manufacture a semiconductor device having a multilayer wiring structure is taken as an example. explain. Here, in order to increase the speed of the semiconductor device, a so-called low resistance metal wiring having a low electric resistance and an interlayer insulating film having a low relative dielectric constant are arranged at predetermined positions to form a multilayer wiring structure. To do.

FIGS. 8A to 8F are cross-sectional views of each step showing the method for manufacturing a semiconductor device according to the sixth embodiment of the present invention. 8 (a) to 8 (f) show cross-sectional views in a direction perpendicular to the longitudinal direction of the pattern.

First, the insulating film 2 is formed on the silicon substrate 201.
02 is formed. In this insulating film 202, the barrier film 20
The first metal wiring layer 204 is formed with 3 interposed therebetween. For the metal wiring layer 204, a low-resistance wiring material such as copper (Cu) wiring, aluminum (Al) wiring, or aluminum alloy wiring is used.

After that, an interlayer insulating film 206 is formed on the insulating film 202 and the metal wiring layer 204 via a barrier film 205.
Is formed with a film thickness of about 800 nm. Here, for the barrier film 205, for example, a silicon nitride film formed by a known plasma CVD method or the like is used. In addition, the interlayer insulating film 206
For this, an insulating film having a low dielectric constant with a relative dielectric constant value of 3.9 or less is used. The low dielectric constant insulating film is an insulating film containing an organic component (hydrocarbon (CH) component or the like) such as an organic silicon oxide film. The interlayer insulating film 206, that is, the organic silicon oxide film is directly formed on the silicon substrate 201 while rotating the silicon substrate 201 by using a known coating method such as a spin coating method.

After that, an organic film 207, an organic silicon oxide film 208, and a photoresist film 209 are sequentially formed on the interlayer insulating film 206 by a coating method to form a multilayer film having a three-layer structure. Each layer of this multilayer film is sequentially processed to transfer the pattern, and a mask pattern having a predetermined shape and size is formed on the member to be processed.

The method for forming each layer constituting the multi-layer film having the three-layer structure will be specifically described below.

First, an organic film 207 having a thickness of about 500 nm is formed as a lower layer film on the interlayer insulating film 206. The organic film 207 has an aromatic ring and carbon (atomic)
The content is 80 wt% or more, preferably 90 wt% or more, and the film has high etching resistance and hardness.
Here, as an example, as the organic film 207, a film having a carbon (atom) content of 93 wt% is used by using a known coating method. The film having such a composition may be formed by the following steps. First, a compound containing carbon (C) is dissolved in a predetermined solvent, that is, an organic solvent to prepare a coating solution. The coating solution is applied in a film form on the interlayer insulating film 206 by rotating the silicon substrate 201 by using a known coating method such as a spin coating method. After that, the applied film is heat-treated and baked at a predetermined temperature. As a result, the organic film 207 is formed on the interlayer insulating film 206 by 50
It is formed with a film thickness of about 0 nm.

The following materials are used to form a coating solution for the organic film 207 which is the lower layer film. Examples of the compound containing carbon (C) include polyarylene, polyarylene ether, phenol resin, phenol novolac, and aromatic polycyclic resin. Moreover, not only these simple substances but also several kinds of compounds can be mixed and used. That is, if it is a compound containing a so-called aromatic ring, dissolve it in a predetermined solvent,
It is possible to easily form an organic film having a (atomic) content of 90 wt% or more (less than 100 wt%). In this embodiment, as an example, an aromatic polycyclic resin is used as the compound containing carbon. The carbon (atomic) content is 9
As an example, it is set to 93 wt% so that it falls within the range of about 0 to 95 wt%.

The predetermined solvent, that is, an organic solvent includes, for example, a ketone solvent such as acetone and methyl ethyl ketone, a cellosolve solvent such as methyl cellosolve and methyl cellosolve acetate, and an ester solvent such as ethyl lactate and ethyl acetate. Solvents, alcoholic solvents such as methanol and ethanol, and anisole and toluene are used.

Here, carbon (atoms) of the organic film 207 is used.
In order to increase the content and to form this by the coating method, carbon
It is necessary to dissolve a high-molecular (atom) content and high molecular compound (hereinafter referred to as a carbon-based polymer material) in a solvent. For that purpose, it is also effective to add a simple substance of oxygen (O), hydrogen (H), or nitrogen (N), or a compound containing them as a modifying group to the carbon-based polymer material. A coating solution can be formed by interacting the above-mentioned organic solvent and a carbon-based polymer material having a high carbon (atom) content with these modifying groups as mediators. Here, the molecular weight of the carbon-based polymer material is adjusted so as to be dissolved in an organic solvent to form a coating solution. Then, when this coating solution is heat-treated at a predetermined temperature, a part of the solvent is vaporized, and at the same time, the molecules of the carbon-based polymer material are chemically bonded to each other by a thermal crosslinking reaction. As a result, the carbon (atomic) content is 90 wt%
The above organic film 207 (less than 100 wt%) can be formed. The organic film thus formed has a higher hardness than a normal photoresist film and has a higher degree of etching resistance.

Next, an organic silicon oxide film 208 of 90 n is formed as an intermediate film on the organic film 207 which is a lower layer film.
It is formed with a film thickness of about m. Organic silicon oxide film 208
Is a kind of known SOG film formed by a coating method.

Generally, when forming a mask pattern from a multilayer film having a three-layer structure, a known SOG film may be used as the intermediate film. It is desirable to make the thickness of the intermediate film as thin as possible so that a pattern can be formed in a predetermined shape and size by a dry etching technique. The SOG film is a silicon oxide film formed by a coating method. Since this SOG film is directly applied onto a rotating silicon substrate by utilizing centrifugal force, it has a feature that its surface is flat and is easily formed into a thin film. Therefore, when the mask pattern is formed by using the multilayer film having the three-layer structure, if the SOG film is used as the intermediate film,
In consideration of the thicknesses of the upper layer film and the lower layer film and the etching selection ratio between the upper layer film and the lower layer film (= difference in etching amount per unit time), the film thickness can be easily made thin.

In this embodiment, the intermediate film is
The material is not particularly limited as long as it is a material that has etching resistance to oxygen plasma that etches the lower layer film, that is, the organic film 207, and that contains a non-volatile component. As a specific material for the intermediate film, for example, an organic silicon oxide film as an oxide containing an organic component or a silicon oxide film (SiO ₂ ) as an oxide containing an inorganic component is used.

Based on the above, in the present embodiment, an organic silicon oxide film, which is a kind of known SOG film, is adopted as an example of the intermediate film. Here, the photoresist film
Based on the thicknesses of the (upper layer film) 209 and the organic film (lower layer film) 207, the organic silicon oxide film 208 is set to 90 as an intermediate film.
It is formed of a thin film of about nm.

The intermediate film may be a film containing silicon as a main component instead of the silicon oxide film. In this case, a film containing silicon as a main component may be formed on the organic film 207 by a known coating method such as a spin coating method. For example, a solution containing silicon is applied in a film shape on the organic film 207 on the rotating silicon substrate 201, and then heat-treated and sintered at a predetermined temperature. Thus, a film containing silicon as a main component is formed as an intermediate film on the organic film 207.

After that, a positive photoresist having photosensitivity is coated on the organic silicon oxide film 208 by using a known coating method such as a spin coating method. continue,
The photoresist applied on the organic silicon oxide film 208 is heat-treated at about 200 to 300 ° C. and baked. As a result, an organic film as an upper layer film, that is, a positive photoresist film 209 is formed on the organic silicon oxide film 208.
To a film thickness of about 300 nm.

In this way, the organic film (lower layer film) 20
7. A multi-layered film having a three-layered structure including an organic silicon oxide film (intermediate film) 208 and a photoresist film (upper film) 209 is formed on the interlayer insulating film 206 which is a member to be processed.

Next, the multilayer film is processed and formed into a mask pattern having a predetermined shape and size by using the lithography technique and the dry etching technique by the following method.

First, as shown in FIG. 8A, a positive photoresist film 209 is formed by using a lithography technique.
The photoresist film 20 is subjected to an exposure process and a development process.
9 forms a pattern. Here, the exposure light is applied to the photoresist film 209 through an exposure mask (reticle) on which a pattern such as a wiring or a via hole (contact hole) is drawn. After that, an unnecessary portion of the photoresist film 209 is removed by using a developing solution. As a result, a pattern having a predetermined shape and dimensions is formed on the photoresist film 209.

Next, using the pattern formed on the photoresist film 209 as a mask, the organic silicon oxide film 208 is formed.
Then, the pattern is sequentially transferred to the organic film 207 by the dry etching technique. After that, the pattern formed on the organic film 207 is used as a main mask, and the pattern shown in FIG.
As shown in FIG. 5, a via hole 210 is formed in the interlayer insulating film 206.

A method for forming a pattern serving as a mask on the organic film 207 and a method for forming the via hole 210 in the interlayer insulating film 206 will be specifically described below.

First, using a dry etching technique, the pattern formed on the photoresist film 209 is used as a mask to transfer the pattern to the organic silicon oxide film 208. Here, using the pattern formed on the photoresist film 209 as a mask, a pattern conforming to the shape and dimensions of the pattern of the photoresist film 209 is formed on the organic silicon oxide film 208. An RIE method suitable for fine processing is adopted as the dry etching technique, and a pattern is formed on the organic silicon oxide film 208 in a reaction container of a reactive ion etching apparatus set to a predetermined condition. As the etching gas, a mixed gas containing CF ₄ , oxygen (O ₂ ) and argon (Ar) is used.

After that, the pattern of the photoresist film 209 and the organic silicon oxide film 208 is used as a mask to transfer the pattern to the underlying organic film 207 by a dry etching technique. Here, the patterns formed on the photoresist film 209 and the organic silicon oxide film 208 are used as a mask to form patterns on the organic film 207 according to the shapes and dimensions of these patterns. The dry etching technique employs an RIE method suitable for fine processing,
A pattern is formed on the organic film 207 in the reaction container of the reactive ion etching apparatus set to a predetermined condition. The etching gas includes oxygen (O ₂ ) and nitrogen (N
The mixed gas of ₂ ) is used.

Since the photoresist film 209 is made of a material having substantially the same quality as that of the organic film 207, it disappears during the etching process for forming a pattern on the organic film 207. Therefore, the interlayer insulating film 206 is processed by etching using the patterns of the organic silicon oxide film 208 and the organic film 207 as a mask as described later.

Then, using the patterns of the organic film 207 and the organic silicon oxide film 208 as a mask, FIG.
As shown in FIG. 3, a via hole 210 having a predetermined opening diameter is formed in the interlayer insulating film 206 so as to reach the barrier film 205 with a depth of about 0.8 μm. Here, the organic silicon oxide film 208 disappears in the process of etching the interlayer insulating film 206, and thereafter, the pattern of the organic film 207 acts as a main mask to form an interlayer insulating film 206 which is a member to be processed. A via hole 210 is formed.

A dry etching technique is used to form the via hole 210. A RIE method suitable for fine processing is adopted as the dry etching technique, and a via hole 210 is formed in the interlayer insulating film 206 in the reaction container of the reactive ion etching apparatus set to a predetermined condition. The etching gas is C ₄ F ₈ and argon.
A mixed gas containing (Ar) is used.

The barrier film 205 is the via hole 21.
In the process of forming 0, it acts as a so-called etching stopper film. Therefore, the etching of the interlayer insulating film 206 is temporarily stopped shortly after reaching the barrier film 205, so that the surface of the first metal wiring layer 204 is not inadvertently damaged.

Next, on the pattern of the organic film 207,
It is a material of the same quality and has a carbon (atomic) content of 90-95w
A t% organic film 211 is applied so as to fill the organic film 207 and the via hole 210. afterwards,
The applied film is heat-treated at about 300 ° C. and baked. As a result, the organic film 211 is formed with the organic film 207 and the via hole 210 filled.

Here, as an example, the organic film 211 is used.
The carbon (atomic) content of is 93 wt%. The film having such a composition may be formed by the following method.
Similar to the organic film 207, a compound containing carbon (C) is dissolved in a predetermined solvent, that is, an organic solvent to prepare a coating solution. This coating solution is directly coated and formed on the rotating silicon substrate 201 by using a known coating method such as a spin coating method. Since the organic film 211 is applied on the structure shown in FIG. 8B in the state of the application solution, the via hole 210 can be easily filled. Furthermore, since it is formed by utilizing the centrifugal force, the surface of the organic film 211 can be formed in a flat state. In addition, organic films 207 and 2 having the same composition
Nos. 11 and 12 have good adhesion to each other and are further heat-treated to sinter each other. Therefore, a stable laminated structure can be maintained while the pattern is formed by etching in the subsequent steps.

Incidentally, in the process of forming the organic film 211, the compound containing carbon (C) and the organic solvent are
It is possible to use the same materials as those listed in the description of the formation process of the organic film 207 and to form a film above the member to be processed by the same method.

Next, the organic silicon oxide film 212 and the positive photoresist film 21 which is an organic film and is photosensitive.
3 and 3 are sequentially formed on the organic film 211 by using a known coating method such as a spin coating method, and a multilayer film having a three-layer structure is formed again.

Thereafter, as shown in FIG. 8C, a pattern is formed on the photoresist film 213 by using the lithography technique. Here, the exposure light is applied to the photoresist film 213 through an exposure mask (reticle) on which a pattern such as wiring is drawn. After that, an unnecessary portion of the photoresist film 213 is removed by using a developing solution, and a pattern having a predetermined shape and size is formed on the photoresist film 21.
3 to form.

Next, using the pattern formed on the photoresist film 213 as a mask, the organic silicon oxide film 212 is used.
Then, the pattern is sequentially transferred to the organic films 207 and 211 by the dry etching technique. After that, the organic film 2
By using the patterns formed in 07 and 211 as a main mask pattern, as shown in FIG. 8D, a trench 214 for wiring having a predetermined depth and width is formed in the interlayer insulating film 206.

Hereinafter, a method of forming a pattern serving as a mask on the organic films 207 and 211, and the interlayer insulating film 20.
A method of forming the wiring groove 214 in 6 will be specifically described.

First, using the pattern formed on the photoresist film 213 as a mask, the pattern is transferred to the organic silicon oxide film 212 by using the dry etching technique. Here, using the pattern formed on the photoresist film 213 as a mask, a pattern conforming to the shape and size of the pattern of the photoresist film 213 is formed on the organic silicon oxide film 212. An RIE method suitable for fine processing is adopted as the dry etching technique, and a pattern is formed on the organic silicon oxide film 212 in a reaction container of a reactive ion etching apparatus set to a predetermined condition. At this time, the etching gas is CF ₄ , oxygen
A mixed gas containing (O ₂ ) and argon (Ar) is used.

Then, using the patterns of the photoresist film 213 and the organic silicon oxide film 212 as a mask, the organic film 207, which is the lower layer film, is formed by a dry etching technique.
The pattern is transferred to 211. Here, the patterns formed on the photoresist film 213 and the organic silicon oxide film 212 are used as masks to form patterns on the organic films 207 and 211 according to the shapes and dimensions of these patterns. An RIE method suitable for fine processing is adopted as the dry etching technique, and a pattern is formed on the organic films 207 and 211 in the reaction container of the reactive ion etching apparatus set to a predetermined condition. At this time, a mixed gas of oxygen (O ₂ ) and nitrogen (N ₂ ) is used as the etching gas.

Since the photoresist film 213 is made of a material having substantially the same quality as the organic films 211 and 207, it disappears in the process of etching for forming a pattern on the organic films 211 and 207. Therefore, the interlayer insulating film 2
06 is an organic silicon oxide film 212 and an organic film 21.
Using the laminated pattern of Nos. 1 and 207 as a mask, a groove 214 for wiring is formed by a dry etching technique. Here, the organic silicon oxide film 212 disappears in the process of etching the interlayer insulating film 206. After that, the laminated pattern of the organic films 207 and 211 acts as a main mask, and the wiring groove 214 is formed in the interlayer insulating film 206 which is the member to be processed.

Unlike the case of using the conventional photoresist film (the content of carbon (atoms) is about 70 wt%), the organic films 207 and 211 as the lower layer film have high etching resistance, and each mask pattern is Even after the etching process by the RIE method, the film thickness is maintained almost constant.

Further, as described above, the organic film 211 is formed by the coating method utilizing the centrifugal force, and has good adhesion to the organic film 207 having the same composition. Therefore, the surface of the organic film 211 is formed substantially flat. Therefore, the organic silicon oxide film 2 which is the intermediate film
12. Even if the photoresist film 213 as the upper layer film is sequentially formed on the organic film 211 in a laminated shape, the flatness of the entire multilayer film can be maintained. As a result, the mask pattern and the wiring groove can be sequentially formed with high dimensional accuracy.

Here, in the dry etching technique used for forming the wiring groove 214, R suitable for fine processing is used.
In the reaction container of the reactive ion etching apparatus which adopts the IE method and is set to a predetermined condition, the interlayer insulating film 2
A groove 214 for wiring is formed in 06. At this time, the etching gas includes CF ₄ , oxygen (O ₂ ) and argon (A
A mixed gas containing r) is used.

Next, the organic films 207 and 211 remaining on the interlayer insulating film 206 and in the via hole 210 are replaced with oxygen.
It is removed by the RIE method using a gas containing (O ₂ ). After that, the barrier film 205 is partially removed by a dry etching technique such as RIE, so that the surface of the first metal wiring layer 204 is exposed in the via hole 210 as shown in FIG.

Next, as shown in FIG. 8F, the barrier film 215 is formed on the inner walls of the via hole 210 and the wiring groove 214.
To form. Then, a wiring material is embedded in the via hole 210 and the wiring groove 214 through the barrier film 215.
In this way, the second metal wiring layer 216 is formed so as to be electrically connected to the first metal wiring layer 204 to form a so-called dual damascene wiring structure. Here, the metal wiring layer 216 is one in which a wiring material is embedded by a known electrolytic plating method or the like. Further, as the wiring material, a wiring material having a low resistance such as copper (Cu) wiring, aluminum (Al) wiring or aluminum alloy wiring is used as in the first metal wiring layer 104.

As described above, a pattern is formed by using a multilayer film having a three-layer structure, and the member to be processed is etched using the pattern as a mask. By using such steps, a semiconductor device having a multilayer wiring structure can be manufactured with high processing accuracy.

In the manufacturing process shown in FIGS. 8A to 8F, a via hole is formed in the process shown in FIG. 8B, and a wiring hole is formed in the process shown in FIG. 8E. The groove 214 was formed. However, it is not always necessary to form in this order, and the groove 214 for wiring may be formed first, and then the via hole 210 may be formed.

Further, in this embodiment, as described above, the mask pattern is formed by using the multilayer film having the three-layer structure to form the multilayer wiring structure. On the other hand, it is also possible to form a mask pattern using a multilayer film having a two-layer structure and process the member to be processed, that is, an interlayer insulating film by using this as a mask to form the above-mentioned multilayer wiring structure. .

In this case as well, an insulating film having a low dielectric constant with a relative dielectric constant value of 3.9 or less is used as the interlayer insulating film. Examples of the low dielectric constant insulating film include an insulating film containing an organic component (hydrocarbon (CH) component etc.) such as an organic silicon oxide film. The multilayer film having a two-layer structure is formed on the member to be processed formed as shown in FIG. 8A, that is, the interlayer insulating film 206 by using a known coating method such as a spin coating method to form a lower layer film and an upper layer film. Formed in order. Here, the lower layer film has an aromatic ring and carbon as in the case of using the multilayer film having the three-layer structure described above.
Content (of atoms) is 80 wt% or more, preferably 90 wt
% Or more, and is a film having a high etching resistance and hardness.

A photoresist film containing an inorganic component such as a semiconductor element or a metal element is used as the upper layer film. In the two-layer structure multilayer film, the upper layer film serves as both the upper layer film and the intermediate film in the three-layer structure multilayer film, and is used as a mask material in the process of forming a pattern by etching the lower layer film. Therefore, the upper layer film needs to contain an inorganic component. Examples of the inorganic component include silicon, aluminum, titanium, tungsten, germanium and the like.

In this embodiment, the case of forming a mask pattern using a multilayer film having a two-layer structure will be described below. First, a pattern is formed by performing an exposure process and a development process on the upper layer film by using a lithography technique. Here, the exposure light is applied to a photoresist film containing an inorganic component such as silicon through an exposure mask (reticle) on which a pattern such as a via / contact hole or wiring is drawn.
After that, unnecessary portions of the photoresist film are removed by using a developing solution to form a predetermined pattern on the upper layer film.

Next, using the pattern of the upper layer film as a mask, the lower layer film, that is, an organic film having a carbon (atom) content of about 93 wt% is processed by a dry etching technique to form the shape of the pattern of the upper layer film. And a mask pattern according to the dimensions is formed on the member to be processed. Here, the RIE method or the like is adopted as the dry etching technique. A mixed gas of oxygen (O ₂ ) and nitrogen (N ₂ ) is used as the etching gas.

When a multilayer wiring structure such as a dual damascene is formed as in this embodiment, a photoresist film containing an inorganic component such as silicon is used instead of both the upper layer film and the intermediate film of the three-layer structure. Then, a multilayer film having a two-layer structure may be formed. A pattern can be formed from this multilayer film, and using this pattern as a mask, via holes and wiring grooves can be formed in the interlayer insulating film as described above.

When the mask pattern is formed on the member to be processed from the multilayer film having the two-layer structure, the number of steps can be reduced as compared with the case where the mask pattern is formed from the multilayer film having the three-layer structure. On the other hand, in the case of forming a mask pattern from the above-mentioned three-layer structure multilayer film, in the process of forming a pattern on the organic film which is the lower layer film, the etching selection ratio (etched amount per unit time from this lower layer film is An intermediate film having a large difference) can be used as a mask material by reducing the film thickness. Therefore, the underlying organic film can be processed with high precision by a dry etching technique using a predetermined etching gas to form a mask pattern in a predetermined shape and size.

In this embodiment, the reactive ion etching (RIE) method is used as the dry etching technique. However, it is not limited to this RIE method,
Regardless of whether the mask pattern is formed from a multilayer film having a two-layer structure or a three-layer structure, a magnetron-type reactive ion etching method, an electron beam ion etching method, an ICP etching method, an ECR ion etching method, or the like is used as a semiconductor device. There is no particular limitation as long as it is suitable for the fine processing.

As described above, in this embodiment, carbon (atoms) is formed in the lower layer film in any case where the mask pattern is formed from a multilayer film having a two-layer structure or a three-layer structure.
An organic film having a content of 80 wt% or more, preferably 90 wt% or more is used. Therefore, by using an organic film having a film thickness smaller than that of the conventional photoresist film (the content of carbon (atoms) is about 70 wt%) and having high etching resistance as a mask material, a multilayer wiring structure such as a dual damascene structure can be obtained. Also in this case, the via / contact hole, the groove for wiring, or the like can be accurately formed in the interlayer insulating film which is the member to be processed. In particular, even when an organic silicon oxide film having a low relative dielectric constant is used as the interlayer insulating film, the etching selection ratio (=) between the lower organic film that is the mask material and the interlayer insulating film is used.
Since it is possible to increase the (difference in the amount to be etched per unit time), it is possible to accurately form the via hole and the wiring groove.

Further, in this embodiment, since the organic film having high etching resistance is used, the mask pattern can be maintained at a substantially constant film thickness even after the via hole is formed in the interlayer insulating film. . Therefore, as in this embodiment, after forming a via hole, a mask pattern is left on the interlayer insulating film and reused as a part of the multilayer film to form a mask pattern to form a wiring groove. can do. As a result, the step of removing the lower layer film can be omitted as much as possible, so that the deterioration of the interlayer insulating film and the increase of the relative dielectric constant can be suppressed. In particular, since it is possible to suppress an increase in the relative dielectric constant in a fine area where the resistance value is likely to increase, such as a via hole, it is possible to reduce the resistance of a semiconductor such as copper (Cu) wiring without damaging the features of the low resistance wiring or the low dielectric constant insulating film. The device can be manufactured.

In the embodiment of the present invention, the member to be processed is etched by using an organic film having an aromatic ring and having a carbon (atom) content of 80 wt% or more as a mask material. Such an organic film has a higher carbon (atomic) content than conventional photoresists, and has higher etching resistance when used as a mask material. Therefore, if the etching processing time of the member to be processed is the same, the film thickness can be formed thinner than the case where the conventional photoresist film is used as the material of the mask. Accordingly, it becomes possible to form a mask pattern with higher dimensional accuracy on the member to be processed, depending on the etching conditions of the member to be processed and processing conditions such as the material thereof.

As described above, according to the embodiment of the present invention, even if the mask material is made thinner, it is possible to sufficiently secure the etching resistance as the mask material and prevent the processing accuracy of the workpiece from being lowered. It is possible to provide a method for manufacturing a semiconductor device.

Further, the embodiment of the present invention is a method for manufacturing a semiconductor device, which can reduce a dimensional conversion difference occurring in a mask pattern after processing in a multilayer resist method and can improve processing accuracy of a processed member. It is possible to provide. Due to the above, even if the miniaturization of the semiconductor device progresses, it becomes possible to accurately process the workpiece.
The reliability of the semiconductor device can be improved.

Further, each of the above-described embodiments is
Not only can it be carried out alone, but it is also possible to carry out it in an appropriate combination.

Furthermore, the above-described embodiments include inventions at various stages, and inventions at various stages can be extracted by appropriately combining a plurality of constituent elements disclosed in each embodiment. Is also possible.

[0174]

As described above, according to the present invention, even if the thinning of the mask material is advanced due to the miniaturization of the semiconductor device,
It is possible to provide a method for manufacturing a semiconductor device in which sufficient etching resistance as a mask material can be ensured and a member to be processed can be processed with high accuracy.

[Brief description of drawings]

FIG. 1 is a sectional view of a first step of a semiconductor device manufacturing method according to an embodiment of the present invention.

FIG. 2 is a sectional view of a second step of the method for manufacturing the semiconductor device according to the embodiment described above.

FIG. 3 is a cross-sectional view of each step showing another first example of the method for manufacturing the semiconductor device of the embodiment of the invention.

FIG. 4 is a sectional view of a step showing another second example of the method for manufacturing the semiconductor device of the embodiment of the invention.

FIG. 5 is a cross-sectional view of each step showing another third example of the method for manufacturing the semiconductor device of the embodiment of the invention.

FIG. 6 is a graph showing the relationship between the carbon content of the mask material pattern and the amount of side etching, which occurs in the mask material etching step in the method for manufacturing a semiconductor device according to the embodiment of the present invention.

FIG. 7 is a graph showing the relationship between the carbon content of the mask material pattern and the etching rate of the mask material pattern, and the carbon of the mask material pattern, which are generated in the step of etching the workpiece in the method for manufacturing a semiconductor device according to the embodiment of the present invention. It is a graph which shows the relationship between content and the processing conversion difference of a to-be-processed member pattern.

FIG. 8 is a sectional view of each step showing the manufacturing method of the semiconductor device according to the other embodiment of the present invention.

[Explanation of symbols]

101 ... Silicon substrate 102 ... Insulating film 103 ... Polycrystalline silicon film 104 ... Silicon nitride film 105 ... Mask material 106 ... Middle layer 107 ... Photoresist film 107A ... Exposed part of photoresist film 107B ... Silylated portion of photoresist film 107C ... Silylated portion of resist pattern 201 ... Silicon substrate 202 ... Insulating film 203 ... Barrier film 204 ... Metal wiring layer 205 ... Barrier film 206 ... Interlayer insulating film 207 ... Organic film 208 ... Organic silicon oxide film 209 ... Photoresist film 210 ... Beer hall 211 ... Organic film 212 ... Organic silicon oxide film 213 ... Photoresist film 214 ... Wiring groove 215 ... Barrier film 216 ... Metal wiring layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI G03F 7/38 512 G03F 7/40 7/40 521 521 H01L 21/28 F H01L 21/027 21/302 H 21/28 21 / 88 D 21/3213 21/90 A 21/768 21/30 502R 575 (72) Inventor Kuki Hayashi 8 Shinsita-cho, Isogo-ku, Yokohama-shi, Kanagawa Toshiba Corporation office (72) Inventor Tokuhisa Oiwa Yokohama, Kanagawa Shinsugita-cho, Isogo-ku, Yokohama-shi, Toshiba Co., Ltd. Yokohama Works (72) Inventor Rennobu Onishi Shin-Sugita-cho, Isogo-ku, Yokohama, Kanagawa, Kanagawa 8 (56) References JP2000-310863 (JP, JP, 310863) A) JP-A-4-287047 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/3065

Claims (16)

(57) [Claims] 1. Dehydrogenation after coating a solution on a workpiece.
Reaction or dehydration condensation reaction to increase the carbon content.
Has an aromatic ring and a carbon atom content of 80 wt.
% Or more of the mask material, a step of etching the mask material into a desired pattern to form a mask material pattern, a step of using the mask material pattern as a mask, and etching the workpiece. A method of manufacturing a semiconductor device, comprising: 2. The step of forming the mask material pattern, the step of forming an intermediate film having at least one of a semiconductor element and a metal element on the mask material, and the step of forming a photoresist film on the intermediate film. A step of forming a resist pattern by subjecting the photoresist film to pattern exposure and development, a step of transferring the resist pattern to the intermediate film to form an intermediate film pattern, the intermediate film The method of manufacturing a semiconductor device according to claim 1, further comprising: transferring a pattern to the mask material to form the mask material pattern. 3. Dehydrogenation after coating a solution on a member to be processed
Reaction or dehydration condensation reaction to increase the carbon content.
Has an aromatic ring and a carbon atom content of 80 wt.
% Or more of the mask material, a step of forming a photoresist film on the mask material, a step of performing a pattern exposure and a development process on the photoresist film to form a resist pattern, the resist A method of manufacturing a semiconductor device, comprising: a step of transferring a pattern to the mask material to form a mask material pattern; and a step of etching the processed member using the mask material pattern as a mask. . 4. The method of manufacturing a semiconductor device according to claim 3, wherein the developing process is performed by a wet developing method. 5. The method of manufacturing a semiconductor device according to claim 4, wherein the resist pattern contains at least one of a semiconductor element and a metal element. 6. The method of manufacturing a semiconductor device according to claim 3, further comprising a step of silylating the resist pattern after the step of forming the resist pattern. 7. The method of manufacturing a semiconductor device according to claim 3, wherein the developing process is performed by a dry developing method. 8. The carbon atom content in the mask material is 90 wt% or more.
8. A method of manufacturing a semiconductor device according to any one of items 7 to 7. 9. The dehydrogenation reaction or the dehydration condensation reaction
2. The heating is performed by heating.
9. The method for manufacturing a semiconductor device according to any one of items 8 to 8. 10. The solution contains a polycyclic aromatic compound.
10. The method of manufacturing a semiconductor device according to claim 1 , wherein the method is a semiconductor device manufacturing method. 11. A weight average molecule of the polycyclic aromatic compound
11. The method for manufacturing a semiconductor device according to claim 10, wherein the amount is in the range of 1000 to 100,000 . 12. A semiconductor substrate with a first insulating film interposed therebetween.
Forming a first wiring layer, and a second insulating film on the first insulating film and the first wiring layer.
A step of forming a film, and a carbon atom having an aromatic ring on the second insulating film.
Form a first organic film whose amount is 80 wt% or more
And a step of forming a semiconductor element and a metal element on the first organic film.
Membrane film containing a first inorganic component having at least one of them
A step of forming a turn, and using the film pattern containing the first inorganic component as a mask,
A step of forming a pattern on the first organic film, and a step of masking the pattern formed on the first organic film.
Any of holes and grooves in the second insulating film.
And a step of forming a layer on the pattern formed on the first organic film,
Has an aromatic ring and a carbon atom content of 80 wt% or more
A step of forming a second organic-based film, and a step of forming a semiconductor element and a metal element on the second organic-based film.
Membrane film containing a second inorganic component having at least one of them
A step of forming a turn, and using the film pattern containing the second inorganic component as a mask,
Form a pattern on at least the second organic film
A step of forming the pattern formed on the second organic film.
Any of a groove and a hole in the second insulating film.
And a step of forming a conductive material in the groove and the hole,
The method of manufacturing a semiconductor device comprising: the step of forming a second wiring layer, characterized by comprising the contact with the wiring layer. 13. Carbon contained in the first organic film
Atomic content and charcoal contained in the second organic film
The content of elementary atoms is 90 wt% or more
The method of manufacturing a semiconductor device according to claim 12 . 14. The first and second organic films are melted.
13. The liquid is formed by applying the liquid.
14. The method for manufacturing a semiconductor device according to 13 . 15. The solution contains a polycyclic aromatic compound.
The method of manufacturing a semiconductor device according to claim 14 , wherein 16. The low dielectric constant insulating film as the second insulating film.
16. The method according to claim 12, wherein
1. A method of manufacturing a semiconductor device according to one .