JPH1184683A - Pattern forming method and production of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance etching selectivity in dry development and to obtain a resist pattern having a rectangular section. SOLUTION: The top of a semiconductor substrate 10 is coated with a resist contg. polyvinyl phenol resin having T-BOC as a protective group and a photo- acid generator to form a resist film 11 and this resist film 11 is patternwise exposed. A silylating agent having three or more functional groups, e.g. liq. tris(dimethylamino)silane 14 is fed to the top of the patternwise exposed resist film 11 and a polysiloxane layer 15 is selectively formed on the surface of the exposed part 11a of the resist film 11. The resist film 11 is then dry-etched using the polysiloxane layer 15 as a mask to form the objective resist pattern 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a pattern and a method of manufacturing a semiconductor device applied to a fine processing technique in a process of manufacturing a semiconductor device or the like.

[0002]

2. Description of the Related Art In recent years, semiconductor devices have been steadily miniaturized, and the design rules of semiconductor devices are 0.25 μm at a practical level and 0.18 to 0.13 μm at a development level.
Has been reached. As an exposure light source, a KrF excimer laser (wavelength: 248 nm) has been developed from an i-line (wavelength: 365 nm), and an ArF excimer laser (wavelength: 193 nm) is being developed.

Incidentally, the resolution R of the exposure light is R = k ₁
As can be seen from the formula of λ / NA, the wavelength is improved by decreasing the wavelength: λ, while the depth of focus D is D = k
_As can be seen from the equation ₂ · λ / NA ² , it decreases as the wavelength: λ decreases. Therefore, in order to improve the depth of focus while maintaining the resolution of the exposure light, a surface resolution process is considered promising.

As a typical example of the surface resolution process, F.C.
The silylation process proposed by oopman et al. is known (Proc. SPIE, 631, p. 34). In the silylation process, after selectively exposing the resist film, the silylation process is performed on the resist film to selectively cause a silylation reaction in an exposed portion or an unexposed portion of the resist film. To form a silicon-containing layer. Thereafter, when the resist film is dry-developed with oxygen plasma using the silicon-containing layer as a mask, a resist pattern is formed in an exposed portion or an unexposed portion of the resist film.

The silylation treatment is performed in a gas phase or a liquid phase,
By the silylation treatment, the silylating agent diffuses into the resist film and reacts with hydroxyl groups in the resist film to form a silicon-containing layer. For example, when a silylation treatment is performed on a resist film containing a polyvinyl phenol resin in a gas phase using hexamethyldisilazane (HMDS) as a silylating agent, the HMDS and the polyvinyl phenol resin are expressed as shown in [Chemical Formula 5]. Perform a great chemical reaction.

[0006]

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In the following, US Pat.
P4,808,511 and Proc. Reg. Tech. Conf. Photopolymer
s, p.177 (1985), a negative-type silylation process for forming a silylation layer only on exposed portions of a resist film will be described with reference to FIGS. 4 (a) to 4 (d). .

First, as shown in FIG. 4 (a), a photoacid generator which generates an acid when irradiated with an energy beam and a protective group is eliminated by the action of the acid to form a phenolic hydroxyl group. A resist containing a phenol resin is coated on the semiconductor substrate 1 to form a resist film 2, and the resist film 2 is exposed to a KrF excimer laser 3 on a mask 4.
Irradiation through.

Next, when the resist film 2 is subjected to a heat treatment, the exposed portion 2a of the resist film 2 is protected from the phenol resin by the action of the acid generated from the photoacid generator by the pattern exposure and the heat treatment. The group is eliminated,
As shown in FIG. 4B, phenolic hydroxyl groups are selectively formed.

Next, as shown in FIG. 4C, when HMDS vapor 5 as a silylating agent is supplied onto the resist film 2 to expose the resist film 2 to the atmosphere of the silylating agent, The silylated layer 6 is selectively formed on the second exposed portion 2a.

Next, as shown in FIG. 4D, an O ₂ plasma 7 is applied to the resist film 2 in an RIE apparatus (not shown).
And the resist film 2 is dry-developed to form a negative resist pattern 8.

[0012]

By the way, in order to form a negative resist pattern having a rectangular cross section, it is necessary to have a large etching selectivity (ratio of etching rate) during dry development. In the conventional pattern forming method, a resist pattern having a rectangular cross section cannot be obtained because the etching selectivity is not large. In order to obtain a resist pattern having a rectangular cross section, considering an unstable factor of dimensional control due to a dimensional shift during dry development, an etching selectivity of 1 is required.
00 or more is required.

In order to increase the etching selectivity in dry development, it is considered important to increase the amount of silicon (silicon density) contained in the silylated layer.

By the way, if a protecting group is introduced into all phenolic hydroxyl groups, the silylation reaction shown in the above [Chemical Formula 5] does not occur at all in the unexposed portion of the resist film, while the exposure of the resist film does not occur. Since the silylation reaction occurs in the portions, the silylation layer should be formed at a high selectivity in the exposed portions.

However, as shown in the above-mentioned reaction formula, only one silicon is introduced into one phenolic hydroxyl group, so that the amount of silicon in the exposed portion of the resist film does not increase so much. Therefore, the etching selectivity is insufficient.

In view of the above, it is an object of the present invention to provide a resist pattern having a rectangular cross section so that the etching selectivity in dry development is 100 or more.

[0017]

Means for Solving the Problems The present inventors have found that when a silylation treatment is performed using a silylating agent having three or more functional groups, a multiple reaction occurs three-dimensionally for one hydroxyl group. It has been found that a three-dimensional polysiloxane is formed, and the amount of silicon contained in the silylated layer becomes extremely large. As a result, an extremely large amount of silicon is introduced into one hydroxyl group, and a three-dimensional polysiloxane chemically stable with respect to O ₂ plasma is formed. It becomes.

For example, a report by Ki-Ho Baik et al. (J. Vac. Sci.
According to Technol., B9, p. 3399), when a gas-phase HMDS is supplied to a novolak resin having no protective group to perform silylation, the etching selectivity is about 11 and low. By the way, in the conventional pattern forming method, since the silicon content is small, the etching selectivity should be lower than 11. Bisdimethylaminodimethylsilane having two functional groups (B (DMA) DS)
When liquid silylation is carried out using, multiple silylation reactions occur, and a large number of silicons are introduced into one hydroxyl group, so that the etching selectivity can be increased to about 23. From the above considerations, when the silylation treatment is performed using a silylating agent having three or more functional groups, the amount of silicon contained in the silylated layer increases, and the etching selectivity in dry development increases. I can understand.

The pattern forming method according to the present invention is based on the above findings. Specifically, a photosensitive resin is coated on a semiconductor substrate to form a resin film, and then the resin is formed. A first step of subjecting the film to pattern exposure, and supplying a silylating agent having three or more functional groups onto the pattern-exposed resin film to selectively expose the surface of the resin film at the exposed portion. A second step of forming a silylated layer;
A third step of performing dry etching on the resin film using the silylation layer as a mask to form a pattern made of the resin film.

According to the pattern forming method of the present invention, since a silylating agent having three or more functional groups is supplied, a multiple silylation reaction occurs in an exposed portion of the resin film.
A silylated layer made of polysiloxane having a high silicon density and a three-dimensional network is formed.

The second step of the pattern forming method of the present invention preferably includes a step of supplying a silylating agent in a liquid phase.

The silylating agent in the second step of the pattern forming method of the present invention has the general formula

[0023]

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(Provided that R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are the same or different and are any of a hydrogen atom, a methyl group, an ethyl group or a butyl group) .)
Is preferably represented by

When a silylating agent represented by the general formula [Chemical Formula 6] is used, an extremely small H atom is adsorbed at a site where no functional group is present in the silylating agent. Since the attack on the Si atoms is more likely to occur, multiple reactions of silylation in the exposed portion of the resin film are more likely to occur.

In this case, the photosensitive resin in the first step includes an acid generator that generates an acid when irradiated with light, and a resin that generates a hydroxyl group or a carboxylic acid group by removing a protective group by the action of an acid. It is preferable to include

In this case, the photosensitive resin in the first step is represented by the general formula

[0028]

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(Provided that R ₇ is a protecting group which is eliminated by the action of an acid) or

[0030]

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(However, R ₈ is preferably a protecting group which is eliminated by the action of an acid.)

A first method of manufacturing a semiconductor device according to the present invention comprises a first step of selectively generating hydroxyl groups on a surface of a first conductive film formed on a semiconductor substrate; A second step of supplying a polyfunctional silylating agent on the surface of the first conductive film to selectively form an interlayer insulating film made of polysiloxane on the surface of a region where a hydroxyl group has been generated in the first conductive film;
Forming a second conductive film on the first conductive film and the interlayer insulating film.

According to the first method for manufacturing a semiconductor device, after a hydroxyl group is selectively generated on the surface of the first conductive film, a polyfunctional silylating agent is supplied to the region where the hydroxyl group is generated. Since an interlayer insulating film made of polysiloxane is selectively formed on the surface, a patterned interlayer insulating film can be formed without performing a photolithography step and a dry etching step.

In the first step of the first method for manufacturing a semiconductor device, a monofunctional silylating agent is supplied to the surface of the first conductive film to remove hydroxyl groups present on the surface of the first conductive film. It is preferable to include a step of terminating with a silyl group and a step of selectively irradiating the surface of the first conductive film with an energy beam to replace the silyl group terminating the hydroxyl group with a hydroxyl group.

According to a second method for manufacturing a semiconductor device according to the present invention, a first step of selectively generating hydroxyl groups on the surface of a film to be processed formed on a semiconductor substrate is provided. A second step of supplying a functional silylating agent to selectively form a polysiloxane film on the surface of a region where a hydroxyl group has been generated in the film to be processed, and using the polysiloxane film as a mask for the film to be processed. And a third step of performing etching.

According to the second method for manufacturing a semiconductor device, after a hydroxyl group is selectively generated on the surface of the film to be processed, a polyfunctional silylating agent is supplied to the surface of the region where the hydroxyl group has been generated. Since a polysiloxane film is selectively formed and dry etching is performed using the polysiloxane film as a mask,
The selectivity of dry etching is extremely high as compared with a resist made of an organic material which is generally used.

In the first step of the second method for manufacturing a semiconductor device, a monofunctional silylating agent is supplied to the surface of the film to be processed, and hydroxyl groups existing on the surface of the film to be processed are terminated with silyl groups. The method preferably includes a step of selectively irradiating the surface of the film to be processed with an energy beam to replace a silyl group terminating the hydroxyl group with a hydroxyl group.

The polyfunctional silylating agent in the second step of the first or second method for manufacturing a semiconductor device preferably has three or more functional groups.

The polyfunctional silylating agent in the second step of the first or second method for manufacturing a semiconductor device is represented by the general formula:

[0040]

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(However, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are the same or different and are any of a hydrogen atom, a methyl group, an ethyl group or a butyl group. .)
Is preferably represented by

The second step of the first or second method for manufacturing a semiconductor device preferably includes a step of supplying a polyfunctional silylating agent in a liquid phase.

[0043]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, a pattern forming method according to a first embodiment of the present invention will be described with reference to FIGS. 1 (a) to 1 (d).

In the pattern forming method according to the first embodiment, a polyvinyl phenol resin having tert-butoxycarboxylic acid ester (hereinafter, referred to as t-BOC) as a protecting group, and an onium salt as a photoacid generator Is dissolved in an organic solvent.

The silylation solution used for the liquid-phase silylation treatment is 30 vol% based on the whole.
Tris (dimethylamino) silane (T (DMA))
A solution obtained by dissolving a silylating agent composed of S) and 2 vol% of N-methyl-2-pyrrolidone (NMP) in a xylene solvent is used.

[0046]

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First, as shown in FIG. 1A, the above-mentioned resist is applied on a silicon substrate 10 to form a resist film 1.
After forming 1, the resist film 11 is subjected to a heat treatment at a temperature of 90 ° C. for 90 seconds. After that, the resist film 11 is irradiated with a KrF excimer laser 13 via a mask 12 having a desired pattern shape.

Next, when the resist film 11 is heated at a temperature of 120 ° C. for 1 minute, an acid is generated from the photoacid generator in the exposed portion 11a of the resist film 11, and the exposed acid 11a is protected by the action of the generated acid. T-BOC which is a group is eliminated, and a phenolic hydroxyl group is generated as shown in FIG. 1 (b).

Next, as shown in FIG. 1C, when the resist film 11 is immersed in the silylation solution 14 for one minute to perform silylation treatment, the resist film 11 is selectively applied only to the exposed portions 11a where phenolic hydroxyl groups are present. Then, a polysiloxane layer 15 is formed.

Next, as shown in FIG. 1D, when the resist film 11 is subjected to dry development by irradiating the resist film 11 with O ₂ plasma 16 in an RIE apparatus, a negative resist pattern 18 is formed.

Hereinafter, the formation mechanism of the polysiloxane layer 15 formed on the exposed portion 11a of the resist film 11 will be described with reference to [Chem. 11].

[0052]

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The phenolic hydroxyl group in polyvinyl phenol in which T-BOC has been eliminated to form a phenolic hydroxyl group, and T (DM) shown in [Chemical Formula 10] which is a silylating agent.
A) S reacts (hereinafter, this reaction is referred to as a first reaction), and one silicon atom is introduced into one phenolic hydroxyl group. Since the mechanism of elimination of T-BOC to generate a phenolic hydroxyl group is well known, the chemical reaction formula is omitted.

Next, two dimethylamino groups (N (CH ₃ ) ₂ ) bonded to the silicon atoms by the action of H ₂ O contained in the silylation solution permeated into the resist film 11.
Is hydrolyzed to form a silanol group having two OH groups (hereinafter, this reaction is referred to as a second reaction).
That is, one silicon atom is introduced and O
The number of H groups is increasing. In this chemical reaction, since the number of OH groups increases, a multiple reaction of silylation described later is likely to occur, but the number of OH groups does not need to increase.

Next, by the action of T (DMA) S and H ₂ O, a silanol group becomes a precursor to cause multiple silylation reactions to form a three-dimensional polysiloxane.
That is, by the repetition of the first reaction and the second reaction, T (DMA) S reacts with the silanol group one after another to form a siloxane layer having a three-dimensional siloxane bond. You.

According to the first embodiment, as shown in [Chemical Formula 10], since the silylating agent has three functional groups, a three-dimensional siloxane bond is formed. The polysiloxane layer composed of the three-dimensionally bonded siloxane has a high silicon density and a sufficient resistance to O ₂ plasma due to the formation of a three-dimensional network of siloxane bonds. High etching selectivity can be obtained.

When the silylating agent has only two functional groups, a two-dimensional siloxane bond (Si—O
Since only a polysiloxane layer having —Si—O—Si—O—Si) is formed, the silicon density cannot be said to be sufficiently high and the resistance to O ₂ plasma is weak.

Therefore, according to the first embodiment, a surface modification layer having a sufficiently high selectivity with respect to dry development can be formed on the surface of the resist film. An accurate resist pattern can be formed.

Further, according to the first embodiment, since a silanol group becomes a precursor and a multiple silylation reaction occurs, the polysiloxane layer can be formed only by a small amount of hydroxyl group in the resist. it can. Therefore, it is not necessary to completely remove all the protective groups by irradiating exposure light with a large energy, so that high sensitivity can be achieved.

In the first embodiment, T (DMA) S is used as a silylating agent. However, the present invention is not limited to this. For example, tris (diethylamino) silane having three functional groups or four functional groups may be used. Any silylating agent having three or more functional groups, such as tetrakis (dimethylamino) silane, may be used.

However, as the silylating agent, as shown in the above [Chemical Formula 6], it has three functional groups and has a Si—
Those having an H bond are preferable because they have higher reactivity of the silylating agent than those having four functional groups and no Si—H bond. The reason is as follows.

The reaction between the OH group present in the resist or the OH group present in the growing polysiloxane and the silylating agent is carried out in such a manner that the OH group reacts with a portion of the silylating agent where no functional group (amino group) is present. It occurs on the basis of the S _N 2 displacement reaction caused by attacking Te. Therefore, when the group bonded to the site where the functional group does not exist in the silylating agent is large, the steric hindrance action of this large group causes
O at a site where no functional group is present in the silylating agent
Since the attack of the H group is prevented, the reaction between the OH group and the silylating agent hardly occurs. However, if an H atom is attached to a portion of the silylating agent where no functional group is present as in the first embodiment, the H atom is extremely small in size, so that the OH group attacks the H atom. This facilitates the first reaction between the phenolic hydroxyl group and the silylating agent, thereby promoting the second reaction.

In the first embodiment, NMP was mixed with the silylation solution. However, NMP was mixed in order to shorten the time of the silylation treatment, and NMP was mixed with the silylation solution. Alternatively, a resist solvent such as PGMEA may be mixed instead of NMP.

As the protective group introduced into the resist, T-BOCt-BOC was used. Instead, a tetrahydropyranyl group, a 3-oxohexyl group,
An isopropyloxy group or an acetal-based protecting group may be used.

Further, although the KrF excimer laser is used as the exposure light, an I-line, an ArF excimer laser, an X-ray, or an electron beam may be used instead.

(Second Embodiment) Hereinafter, a method for manufacturing a semiconductor device according to a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to (a) to (d).

In the second embodiment, the silylation solution used for the liquid-phase silylation treatment is 30
vol% tris (dimethylamino)
A solution in which a silylating agent composed of silane (T (DMA) S) is dissolved in a xylene solvent is used.

First, as shown in FIG. 2A, a silicon oxide film layer 21 and a first wiring layer 22 made of aluminum are sequentially formed on a silicon substrate 20, and then the first wiring layer 22 is formed. Gas phase hexamethyldisilazane (H
(MDS). In this case, the HMDS reacts with the hydroxyl group present on the surface of the first wiring layer 22 to replace the hydroxyl group with the trimethylsilyl group, so that the monolayer 23 made of trimethylsilyl is formed on the first wiring layer 22. It is formed.

Next, as shown in FIG. 2B, the monolayer 23 made of trimethylsilyl is irradiated with an ArF excimer laser 25 through a mask 24 having a desired pattern shape. By doing so, the exposed portion of the monolayer 23 volatilizes, and a hydroxyl group appears again on the surface of the exposed portion of the first wiring layer 22.

Next, as shown in FIG. 2C, when the first wiring layer 22 is immersed in the above-mentioned silylation solution 26 for one minute to perform silylation treatment, the hydroxyl groups in the first wiring layer 22 are present. The polysiloxane layer 27 is selectively formed only on the exposed portions.

Next, as shown in FIG. 2D, after the remaining monolayer 23 made of trimethylsilyl is removed by irradiating O ₂ plasma, a second wiring layer 28 made of aluminum is deposited on the entire surface. I do. Since the selectively formed polysiloxane layer 27 has a low relative dielectric constant, it becomes a good interlayer insulating film between the first wiring layer 22 and the second wiring layer 28.

According to the second embodiment, the interlayer insulating film composed of the polysiloxane layer 27 can be selectively formed without requiring a photolithography step and a dry etching step. Therefore, the polysiloxane layer 2
7 can significantly reduce the number of steps of forming the interlayer insulating film.

Further, according to the second embodiment, as described above, since the polysiloxane layer 27 made of siloxane bonded three-dimensionally is formed, an interlayer insulating film having excellent heat resistance can be obtained.

In the second embodiment, T (DMA) S is used as a silylating agent. However, the present invention is not limited to this.
For example, bisdimethylaminodimethylsilane (B (DMA) DS) having two functional groups, tris (diethylamino) silane having three functional groups, or tetrakis (dimethylamino) silane having four functional groups, Any silylating agent having two or more functional groups may be used.

However, as the silylating agent, one having three functional groups and having a Si—H bond is preferable because the reactivity of the silylating agent is high as described above.

Although an ArF excimer laser is used as the exposure light, an I-ray, a KrF excimer laser, an X-ray, or an electron beam may be used instead.

Although the aluminum film is used as the first wiring layer 22 which is the base film for forming the monolayer 23 made of trimethylsilyl, a polysilicon film or a tungsten silicide film may be used instead. .

(Third Embodiment) Hereinafter, a method of manufacturing a semiconductor device according to a third embodiment of the present invention will be described with reference to FIG.
This will be described with reference to (a) to (d).

In the third embodiment, the silylation solution used for the liquid-phase silylation treatment is 30
vol% tris (dimethylamino)
A solution in which a silylating agent composed of silane (T (DMA) S) is dissolved in a xylene solvent is used.

First, as shown in FIG. 3A, a silicon oxide film 31 and a metal film 32 made of aluminum are sequentially formed on a silicon substrate 30, and the surface of the metal film 32 is A silylation treatment is performed using disilazane (HMDS). By doing so, the HMDS reacts with the hydroxyl group present on the surface of the metal film 32, and the hydroxyl group is replaced with a trimethylsilyl group, so that a monolayer 33 made of trimethylsilyl is formed on the metal film 32.

Next, as shown in FIG. 3B, the monolayer 33 made of trimethylsilyl is irradiated with an ArF excimer laser 35 through a mask 34 having a desired pattern shape. By doing so, the exposed portion of the monolayer 33 is volatilized, and the hydroxyl group appears again on the surface of the exposed portion of the metal film 32.

Next, as shown in FIG.
2 is immersed in the silylation solution 36 for one minute to perform the silylation treatment, whereby the polysiloxane layer 37 is selectively formed only on the exposed portions of the metal film 32 where the hydroxyl groups are present.

Next, as shown in FIG.
Dry etching 38 is performed using the polysiloxane layer 37 formed selectively with respect to 2 as a mask to form a metal wiring layer 39 made of the metal film 32.

According to the third embodiment, a dry etching selectivity of about 10 can be obtained, and dry etching using a commonly used resist made of an organic material as a mask (selectivity is about 2). Since the selectivity of dry etching is extremely higher than that of the above, a wiring pattern having a good shape can be obtained.

According to the third embodiment, as described above, since the polysiloxane layer 37 made of siloxane bonded three-dimensionally is formed, a mask excellent in dry etching resistance can be obtained. Metal film 32
Can be processed with high precision.

In the third embodiment, T (DMA) S is used as a silylating agent. However, the present invention is not limited to this.
For example, bisdimethylaminodimethylsilane (B (DMA) DS) having two functional groups, tris (diethylamino) silane having three functional groups, or tetrakis (dimethylamino) silane having four functional groups, Any silylating agent having two or more functional groups may be used.

However, as the silylating agent, one having three functional groups and having a Si—H bond is preferable because the reactivity of the silylating agent is high as described above.

Although the ArF excimer laser is used as the exposure light, an I-ray, a KrF excimer laser, an X-ray, or an electron beam may be used instead.

Although the aluminum film is used as the metal film 32 to be processed, a polysilicon film or a tungsten silicide film may be used instead.

[0090]

According to the pattern forming method of the present invention, 3
Since a silylating agent having one or more functional groups is supplied, a silylated layer composed of polysiloxane having a high silicon density, a three-dimensional network, and sufficient resistance to O ₂ plasma is formed. , A high etching selectivity of about 100 can be obtained. As described above, a silylated layer having a sufficiently high selectivity with respect to dry development can be formed on the surface of the exposed portion of the resist film, and the pattern width of the silylated layer can be faithfully reflected in the pattern dimension. A high-precision resist pattern having a cross-section can be formed, and since the silicon density of the silylated layer is high, the energy of the exposure light can be suppressed, so that high sensitivity can be achieved in the exposure step.

In the second step of the pattern forming method of the present invention, if the silylating agent is supplied in a liquid phase, the silylation reactivity is improved, so that a polysiloxane having a high silicon density can be surely formed. .

When a silylating agent represented by the general formula [Chemical Formula 6] is used as the silylating agent in the second step of the pattern forming method of the present invention, an attack on an H atom of an OH group is likely to occur. Multiple reactions of silylation in the exposed area are more likely to occur, and a polysiloxane having a higher silicon density can be formed, so that the etching selectivity in dry development can be further increased.

In this case, when the photosensitive resin contains an acid generator that generates an acid upon irradiation with light and a resin that generates a hydroxyl group or a carboxylic acid group by the removal of a protective group by the action of an acid, the resist film Since the silylated layer made of polysiloxane can be reliably formed only on the exposed portion, a negative pattern having a rectangular cross section can be reliably formed by dry development. Further, since a small amount of a hydroxyl group or a carboxylic acid group can form a polysiloxane as a precursor, it is not necessary to completely remove the protective group by exposure, and thus the energy of exposure light can be suppressed. Therefore, a negative-type register pattern having a high etching selectivity and a high dimensional accuracy can be formed.

In this case, when the photosensitive resin is represented by the general formula [Chemical formula 7] or [Chemical formula 8], the reactivity of the silylation reaction in the exposed portion of the resist film can be further increased. Higher density polysiloxanes can be formed.

According to the first method for manufacturing a semiconductor device, an interlayer insulating film made of polysiloxane can be selectively formed on the surface of the first conductive film, so that the pattern can be formed without performing a photolithography step and a dry etching step. Since a simplified interlayer insulating film can be formed, the step of forming the interlayer insulating film can be greatly reduced.

The first step of the first method for manufacturing a semiconductor device is to supply a monofunctional silylating agent to the surface of the first conductive film to terminate hydroxyl groups present on the surface with the silyl group. ,
When a step of selectively irradiating an energy beam to replace a silyl group terminating a hydroxyl group with a hydroxyl group is included, the step of selectively generating a hydroxyl group on the surface of the first conductive film can be surely performed. it can.

According to the second method for manufacturing a semiconductor device, dry etching is performed using the polysiloxane film selectively formed on the surface of the film to be processed as a mask, so that the dry etching is performed in comparison with a resist made of a commonly used organic material. As a result, the selectivity of dry etching becomes extremely high, so that a pattern composed of a film to be processed having a good sectional shape can be formed.

In the first step of the second method for manufacturing a semiconductor device, a monofunctional silylating agent is supplied to the surface of the film to be processed to terminate the hydroxyl groups present on the surface with the silyl group. When the step of selectively irradiating a beam to replace the silyl group terminating the hydroxyl group with the hydroxyl group is included, the step of selectively generating the hydroxyl group on the surface of the film to be processed can be reliably performed.

When a silylating agent represented by the general formula [Chemical Formula 9] is used as a silylating agent in the second step of the first or second method for manufacturing a semiconductor device, an attack on an H atom of an OH group is likely to occur. Therefore, multiple reactions of silylation are more likely to occur, and a polysiloxane having a higher silicon density can be formed.

In the second step of the first or second method for producing a semiconductor device, if the silylating agent is supplied in a liquid phase, the silylation reactivity is ensured, so that the polysiloxane having a high silicon density can be reliably obtained. Can be formed.

[Brief description of the drawings]

FIGS. 1A to 1D are cross-sectional views showing respective steps of a pattern forming method according to a first embodiment of the present invention.

FIGS. 2A to 2D are cross-sectional views illustrating respective steps of a method for manufacturing a semiconductor device according to a second embodiment of the present invention.

FIGS. 3A to 3D are cross-sectional views illustrating respective steps of a method for manufacturing a semiconductor device according to a third embodiment of the present invention.

FIGS. 4A to 4D are cross-sectional views showing respective steps of a conventional pattern forming method.

[Explanation of symbols]

10 semiconductor substrate 11 resist film 11a exposed portion 12 mask 13 KrF excimer laser 14 silylating solution 15 polysiloxane layer 16 O ₂ plasma 18 resist pattern 20 silicon substrate 21 a silicon oxide film layer 22 monolayer 24 consisting of the first wiring layer 23 trimethylsilyl Mask 25 ArF excimer laser 26 Silylation solution 27 Polysiloxane layer 28 Second wiring layer 30 Semiconductor substrate 31 Silicon oxide film 32 Metal film 33 Monolayer made of trimethylsilyl 34 Mask 35 ArF excimer laser 36 Silylation solution 37 Polysiloxane layer 38 Metal Wiring layer 39 Dry etching

Claims (12)

[Claims] A first step of applying a photosensitive resin on a semiconductor substrate to form a resin film and then subjecting the resin film to pattern exposure; A second step of supplying a silylating agent having at least one functional group to selectively form a silylated layer on the surface of the exposed portion of the resin film; A third step of forming a pattern made of the resin film by performing dry etching as a mask. 2. The pattern forming method according to claim 1, wherein the second step includes a step of supplying the silylating agent in a liquid phase. 3. The silylating agent in the second step,
General formula (However, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are the same or different and are any of a hydrogen atom, a methyl group, an ethyl group or a butyl group.) The pattern forming method according to claim 1, wherein the pattern is formed. 4. The photosensitive resin in the first step,
The pattern formation according to claim 3, comprising an acid generator that generates an acid when irradiated with light, and a resin that generates a hydroxyl group or a carboxylic acid group by removing a protecting group by the action of the acid. Method. 5. The photosensitive resin in the first step,
General formula (However, R ₇ is a protecting group which is eliminated by the action of an acid.) Or 4. The pattern forming method according to claim 3, wherein R ₈ is a protecting group which is eliminated by the action of an acid. 6. A first step of selectively generating a hydroxyl group on a surface of a first conductive film formed on a semiconductor substrate; and a polyfunctional silylating agent on the first conductive film. A second step of supplying and selectively forming an interlayer insulating film made of polysiloxane on a surface of a region where a hydroxyl group is generated in the first conductive film; And a third step of forming a second conductive film. 7. In the first step, a monofunctional silylating agent is supplied to the surface of the first conductive film, and a hydroxyl group present on the surface of the first conductive film is terminated with a silyl group. 7. The method according to claim 6, further comprising: irradiating an energy beam selectively to a surface of the first conductive film to replace the silyl group terminating the hydroxyl group with a hydroxyl group. The manufacturing method of the semiconductor device described in the above. 8. A first step of selectively generating a hydroxyl group on a surface of a film to be processed formed on a semiconductor substrate, and supplying a polyfunctional silylating agent onto the film to be processed,
A second step of selectively forming a polysiloxane film on the surface of the region where the hydroxyl groups have been generated in the film to be processed; and a third step of etching the film to be processed using the polysiloxane film as a mask. A method for manufacturing a semiconductor device, comprising: 9. The first step comprises: supplying a monofunctional silylating agent to the surface of the film to be processed to terminate hydroxyl groups present on the surface of the film to be processed with a silyl group; 9. A method of manufacturing a semiconductor device according to claim 8, comprising a step of selectively irradiating an energy beam to a surface of the film to be processed to replace the silyl group terminating a hydroxyl group with a hydroxyl group. Method. 10. The method for manufacturing a semiconductor device according to claim 6, wherein the polyfunctional silylating agent in the second step has three or more functional groups. 11. The polyfunctional silylating agent in the second step is represented by the general formula: (However, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are the same or different and are any of a hydrogen atom, a methyl group, an ethyl group or a butyl group.) The method of manufacturing a semiconductor device according to claim 6, wherein: 12. The method of manufacturing a semiconductor device according to claim 6, wherein the second step includes a step of supplying the polyfunctional silylating agent in a liquid phase.