JP3361445B2 - Pattern forming method and surface treatment agent - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern forming method for forming a resist pattern on a semiconductor substrate in a semiconductor device manufacturing process, and a surface treatment agent used in the resist pattern forming process.

[0002]

2. Description of the Related Art In recent years, as the density and integration of semiconductor devices have increased, the need for fine processing technology has increased more and more.

As a first measure for enabling fine processing in the lithography process, Japanese Patent Laid-Open No. 58-1881.
As disclosed in Japanese Patent No. 32, a technique for improving the adhesion between a semiconductor substrate and a resist pattern has been proposed.

A pattern forming method using a resist containing, for example, a phenolic resin will be described below as a first conventional example.

First, on the surface of a semiconductor substrate made of silicon, the general formula: R ⁸ SiX _3-n R ⁹ _n (where n is 0, 1 or 2, X is halogen or --OR ¹⁰ group (R ¹⁰ an alkyl group having 1 to 3 carbon atoms), R ⁸ is CH ₂ = CH-,
ZCH ₂ — (Z is halogen) or a group containing the following [Chemical Formula 3], and R ⁹ is hydrogen or an alkyl group having 1 to 3 carbon atoms. By supplying a surface treatment agent containing a silane compound represented by (4) to make the surface of the semiconductor substrate hydrophobic, the adhesion of the semiconductor substrate is improved.

[0006]

[Chemical 3]

Next, after a resist containing, for example, a phenol resin is applied to the surface of the semiconductor substrate to form a resist film, the resist film is exposed using a desired mask, and then post exposure bake is performed. (Hereinafter, abbreviated as PEB) and development are sequentially performed to form a resist pattern.

As a second measure for enabling fine processing in the lithography process, DUV light using an excimer laser as a light source or short wavelength light such as EB or X-ray is used as exposure light and acid is used as a resist. Technology for forming a resist pattern consisting of chemically amplified resist that utilizes generation is being developed ("Coloring Material", Vol. 67N
o. 7, pp446-455 (1994)).

Hereinafter, referring to FIGS. 8 and 9, the second
As a conventional example, a pattern forming method using a chemically amplified resist will be described.

FIG. 8 shows a process flow of a pattern forming method according to the second conventional example, and FIG. 9 shows a surface state of a semiconductor substrate formed by the pattern forming method according to the second conventional example.

First, hexamethyldisilazane (hereinafter abbreviated as HMDS) as a surface treatment agent is supplied to the surface of the semiconductor substrate 1 made of silicon to make the surface of the semiconductor substrate 1 hydrophobic to make the semiconductor substrate 1 1. Adhesion is improved. This treatment is performed by bubbling liquid HMDS with nitrogen gas and then spraying HMDS onto the surface of the semiconductor substrate 1 heated to 60 ° C. for 30 seconds, as shown in FIG. 9A. If this is done, FIG.
As shown in (b), H of the OH group on the surface of the semiconductor substrate 1
Is replaced by Si (CH ₃ ) ₃ (trimethylsilyl group), the surface of the semiconductor substrate 1 becomes hydrophobic, the adhesion of the semiconductor substrate 1 is improved, and NH ₃ (ammonia) is generated.

Next, after a chemically amplified resist is applied to the surface of the semiconductor substrate 1 to form a resist film, the resist film is exposed using a desired mask, and then PE is used.
B and development are sequentially performed to form a resist pattern.

[0013]

Since the resist pattern formed on the semiconductor substrate by the pattern forming method according to the first conventional example is the surface of the semiconductor substrate treated with the above surface treating agent. , The adhesion between the semiconductor substrate and the resist pattern is better than before,
There is a first problem in that the adhesiveness is not satisfactory when further fine processing is performed in the lithography process. That is, for example, pattern peeling may occur in pattern formation of 0.30 μm or less by i-line exposure, pattern formation of 0.25 μm or less by KrF excimer laser exposure, or pattern formation of 0.20 μm or less by ArF excimer laser exposure. .

FIG. 10 shows a schematic sectional shape of a resist pattern 2 formed on a semiconductor substrate 1 made of silicon by the pattern forming method according to the second conventional example. That is, in FIG. 10, a positive chemically amplified resist (KRF K2G manufactured by Japan Synthetic Rubber Co., Ltd.) is applied to a semiconductor substrate 1 made of silicon to a film thickness of 0.7 μm, and then NA: 0.5 is applied. Exposure with a KrF excimer laser stepper, then PEB for 90 seconds at a temperature of 100 ° C., and development with a 2.38 wt% tetramethylammonium hydroxide aqueous solution of 0.25 μm line and space The cross-sectional shape of the pattern is shown.

According to the second conventional example, as shown in FIG. 10, the poorly soluble layer 3 is formed on the surface portion of the resist pattern 2. It is considered that the hardly soluble layer 3 is formed on the surface portion of the resist pattern 2 because the atmosphere at the time of pattern formation is different.

Hardly soluble layer 3 on the surface of resist pattern 2
However, there is a second problem that the subsequent process is adversely affected and causes a decrease in the yield of semiconductor devices.

In view of the above, the present invention further improves the adhesion between the semiconductor substrate and the resist pattern, and
When a chemically amplified resist is used as the resist, it is an object to prevent the insolubilized layer from being formed on the surface portion of the resist pattern.

[0018]

As a result of various investigations, the present inventors have found that when a surface treatment of a semiconductor substrate is performed using a surface treatment agent containing a silane compound represented by the following general formula (1), a resist pattern is obtained. It was found that the surface adhesiveness of the is improved.

[0019]

[Chemical 4]

(Wherein R ¹ , R ² and R ³ are the same or different and are a hydrogen atom, a substituted saturated hydrocarbon group having 1 to 6 carbon atoms or an unsubstituted saturated hydrocarbon group, and 1 to 6 carbon atoms. A substituted unsaturated hydrocarbon group or an unsubstituted unsaturated hydrocarbon group,
Or an alicyclic saturated hydrocarbon group having 3 to 6 carbon atoms, R
⁴ , R ⁵ and R ⁶ are the same or different and are a hydrogen atom,
OR ⁷ (R ⁷ represents a hydrogen atom, a substituted saturated hydrocarbon group having 1 to 6 carbon atoms or an unsubstituted saturated hydrocarbon group, 1 to 6 carbon atoms.
Is a substituted unsaturated hydrocarbon group or an unsubstituted unsaturated hydrocarbon group, or an alicyclic saturated hydrocarbon group having 3 to 6 carbon atoms. ) A substituted saturated hydrocarbon group or an unsubstituted saturated hydrocarbon group having 1 to 6 carbon atoms, a substituted unsaturated hydrocarbon group or an unsubstituted unsaturated hydrocarbon group having 1 to 6 carbon atoms, or an alicyclic ring having 3 to 6 carbon atoms Formula is a saturated hydrocarbon group. That is, since the silane compound represented by the general formula (1) has a low energy level of the electrophilic orbit, the reactivity of the trimethylsilyl group of the silane compound with the OH group on the substrate is high. Therefore, as described above, the silicon atom constituting the silane compound having a carbonyl group reacts with the silanol group, which is a compound having an active hydrogen atom, at an extremely high reaction rate.

Therefore, the silane compound represented by the general formula (1) reacts extremely quickly with the silanol groups present on the surface of the semiconductor substrate, and as a result, the surface of the semiconductor substrate tends to be hydrophobic.

In order to prove that the reaction rate between the silane compound represented by the general formula (1) and the silanol group is higher than the reaction rate between the conventional hexamethyldisilazane and the silanol group, the following reaction is performed. An experiment was conducted. That is, 4-trimethylsiloxy-3-penten-2-one, which is an example of the silane compound represented by the general formula (1), was mixed with 0.5 equivalent of cyclohexanol and the reaction rate was measured. A very high reaction rate of 100% was obtained. On the other hand, when HMDS was mixed with 0.5 equivalent of cyclohexanol and the reaction rate was measured, a reaction rate of 43.9% was obtained in 24 hours.

As a result of various studies on the cause of the formation of the insolubilized layer on the surface portion of the resist pattern, the present inventors have found that the cause is the alkaline component. That is, when an alkaline component is present on the surface of the resist pattern, the acid generated by exposure is deactivated to form a surface insolubilized layer, and the surface portion of the resist pattern has a T-top.
It is a shape. This means that the pattern may not be resolved when the alkaline component is high (SAMacDonald et al., Proc.SPIE, vol.1466, p.2 (19
91)) It can be understood from the above.

In order to investigate the cause of generation of the ammonia component as an alkaline component which adversely affects the chemically amplified resist, impurities in the environment were analyzed in a clean room. As shown in FIG. 11, it was a decomposition product of HMDS. It was found that there was a positive correlation between the environmental concentrations of trimethylsilanol and ammonia. From this, it is presumed that the alkaline component that adversely affects the pattern shape of the chemically amplified resist is caused by HMDS, which is the surface treatment agent for the semiconductor substrate.

The present invention was made on the basis of the above findings, and by using a surface treatment agent containing a silane compound represented by the above general formula (1) in place of conventional HMDS, a semiconductor substrate is obtained. To improve the adhesion between the resist pattern and the resist pattern, and when using a chemically amplified resist, prevent the formation of an alkali component on the surface of the semiconductor substrate and prevent the formation of a poorly soluble layer on the surface of the resist pattern. Is.

Specifically, the pattern forming method according to the present invention comprises a first step of subjecting the surface of a semiconductor substrate to a surface treatment agent containing a silane compound represented by the following general formula (1): A second step of forming a resist film by applying a resist on the surface of the surface-treated semiconductor substrate;
A third step of forming a resist pattern by exposing the resist film using a mask having a desired pattern shape and then developing the resist film is provided.

[0027]

[Chemical 5]

(Wherein R ¹ , R ² and R ³ are the same or different and are a hydrogen atom, a substituted saturated hydrocarbon group having 1 to 6 carbon atoms or an unsubstituted saturated hydrocarbon group, and 1 to 6 carbon atoms. A substituted unsaturated hydrocarbon group or an unsubstituted unsaturated hydrocarbon group,
Or an alicyclic saturated hydrocarbon group having 3 to 6 carbon atoms, R
⁴ , R ⁵ and R ⁶ are the same or different and are a hydrogen atom,
OR ⁷ (R ⁷ represents a hydrogen atom, a substituted saturated hydrocarbon group having 1 to 6 carbon atoms or an unsubstituted saturated hydrocarbon group, 1 to 6 carbon atoms.
Is a substituted unsaturated hydrocarbon group or an unsubstituted unsaturated hydrocarbon group, or an alicyclic saturated hydrocarbon group having 3 to 6 carbon atoms. ) A substituted saturated hydrocarbon group or an unsubstituted saturated hydrocarbon group having 1 to 6 carbon atoms, a substituted unsaturated hydrocarbon group or an unsubstituted unsaturated hydrocarbon group having 1 to 6 carbon atoms, or an alicyclic ring having 3 to 6 carbon atoms Formula is a saturated hydrocarbon group. According to the pattern forming method of the present invention, since the semiconductor substrate is surface-treated with the surface treatment agent containing the silane compound represented by the general formula (1), the hydrophobicity of the surface of the semiconductor substrate is improved and Adhesion with the resist pattern is improved.

In the pattern forming method of the present invention, the resist in the second step is a chemically amplified resist containing an acid generator and a resin which becomes alkali-soluble by the action of an acid, or an acid generator. Chemically amplified resist containing an alkali-soluble resin and a compound or resin that becomes alkali-soluble by the action of an acid, or an acid generator, an alkali-soluble resin, and a compound or resin that causes a crosslinking reaction by the action of an acid Can be a chemically amplified resist.

When the resist of the second step is the chemically amplified resist as described above, the semiconductor substrate is surface-treated with the surface treatment agent containing the silane compound represented by the general formula (1). No alkaline component is generated on the surface of the semiconductor substrate.

In the pattern forming method of the present invention, the resist in the second step may contain a naphthoquinonediazide compound and a novolac resin.

The surface treating agent according to the present invention is a surface treating agent for treating the surface of a semiconductor substrate and contains a silane compound represented by the following general formula (1).

[0033]

[Chemical 6]

(However, R ¹ , R ² and R ³ are the same or different and are hydrogen atoms, a substituted saturated hydrocarbon group having 1 to 6 carbon atoms or an unsubstituted saturated hydrocarbon group, and 1 to 6 carbon atoms. A substituted unsaturated hydrocarbon group or an unsubstituted unsaturated hydrocarbon group,
Or an alicyclic saturated hydrocarbon group having 3 to 6 carbon atoms, R
⁴ , R ⁵ and R ⁶ are the same or different and are a hydrogen atom,
OR ⁷ (R ⁷ represents a hydrogen atom, a substituted saturated hydrocarbon group having 1 to 6 carbon atoms or an unsubstituted saturated hydrocarbon group, 1 to 6 carbon atoms.
Is a substituted unsaturated hydrocarbon group or an unsubstituted unsaturated hydrocarbon group, or an alicyclic saturated hydrocarbon group having 3 to 6 carbon atoms. ) A substituted saturated hydrocarbon group or an unsubstituted saturated hydrocarbon group having 1 to 6 carbon atoms, a substituted unsaturated hydrocarbon group or an unsubstituted unsaturated hydrocarbon group having 1 to 6 carbon atoms, or an alicyclic ring having 3 to 6 carbon atoms Formula is a saturated hydrocarbon group. ) When the surface of the semiconductor substrate is treated with the surface treatment agent containing the silane compound represented by the general formula (1), the hydrophobicity of the surface of the semiconductor substrate is improved and the adhesion between the semiconductor substrate and the resist pattern is improved. .

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION (First Reference Embodiment) A pattern forming method according to a first reference embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a process flow of a pattern forming method according to the first or second reference embodiment, and FIG.
FIG. 3B shows the surface condition of the semiconductor substrate when the surface treatment with the surface treatment agent according to the first or second reference embodiment is performed, and FIG. 3 shows the surface treatment with the surface treatment agent according to the first reference embodiment. The schematic cross-sectional shape of the resist pattern formed on the semiconductor substrate is shown.

First, as shown in FIG. 2A, 4-trimethylsiloxy-3-as shown in the following [Chemical Formula 7] as a surface treatment agent is applied to the surface of the semiconductor substrate 1 made of silicon.
Supplying penten-2-one (that is, bubbling 4-trimethylsiloxy-3-penten-2-one with nitrogen gas and spraying on the surface of the semiconductor substrate heated to 90 ° C. for 30 seconds) to obtain a semiconductor substrate The surface of 1 is made hydrophobic to improve the adhesiveness of the semiconductor substrate 1.

[0038]

[Chemical 7]

By doing so, as shown in FIG. 2B, H of the OH group on the surface of the semiconductor substrate 1 becomes Si (CH ₃ ).
CH ₃ COCH ₂ C substituted with ₃ (trimethylsilyl group)
OCH ₃ (acetylacetone) is produced.

Next, a resist is applied to the surface of the semiconductor substrate 1 and then exposed using a desired mask, and then PE
Pattern formation is performed by sequentially performing B and development.

When the pattern is formed as described above,
As shown in FIG. 3, a resist pattern 4 having a good shape with no peeling portion was formed on the semiconductor substrate 1. That is, in FIG. 3, a positive type resist (PFI-38 manufactured by Sumitomo Chemical Co., Ltd.) is applied on the semiconductor substrate 1 to a film thickness of 1.0 μm, and then exposed by an i-line stepper with NA: 0.6. After that, PEB is performed at a temperature of 100 ° C. for 90 seconds, and development is performed using a 2.38 wt% tetramethylammonium hydroxide aqueous solution. The cross-sectional shape of the 0.30 μm line-and-space resist pattern 4 is shown. Is shown.

As described above, according to the first reference embodiment,
Since 4-trimethylsiloxy-3-penten-2-one is used as the surface treatment agent, the adhesiveness with the semiconductor substrate 1 can be enhanced, and the resist pattern 4 having a good shape with no peeling portion can be obtained. .

In the first reference embodiment, the semiconductor substrate 1
Since the adhesion between the resist pattern 4 and the resist pattern 4 depends on the hydrophobicity of the surface-treated semiconductor substrate 1, the type of the resist forming the resist pattern 4 is not limited, and a naphthoquinone diazide compound and a novolac resin are mainly used. A resist containing the same, a two-component system chemically amplified positive resist containing an acid generator and a resin which becomes alkali-soluble by the action of an acid, a compound or a resin which becomes alkali-soluble by the action of an acid generator, an alkali-soluble resin and an acid. It is possible to widely use a three-component type positive chemically amplified resist contained therein, or a chemically amplified negative resist containing an acid generator, an alkali-soluble resin and a compound or resin which causes a crosslinking reaction by the action of an acid.

(Second Reference Embodiment) A pattern forming method according to a second reference embodiment of the present invention will be described below with reference to FIGS. 1, 2 and 4. FIG. 4 shows a schematic cross-sectional shape of a resist pattern formed on a semiconductor substrate surface-treated with the surface-treating agent according to the second reference embodiment.

First, as shown in FIG. 2 (a), 4-trimethylsiloxy-3-as shown in the above [Chemical Formula 7] is used as a surface treatment agent on the surface of the semiconductor substrate 1 made of silicon.
Supplying penten-2-one (that is, bubbling 4-trimethylsiloxy-3-penten-2-one with nitrogen gas and spraying on the surface of the semiconductor substrate heated to 90 ° C. for 30 seconds) to obtain a semiconductor substrate The surface of 1 is made hydrophobic to improve the adhesiveness of the semiconductor substrate 1. By doing so, as shown in FIG. 2B, H of the OH group on the surface of the semiconductor substrate 1 becomes Si (CH ₃ ) ₃ (trimethylsilyl group).
To produce CH ₃ COCH ₂ COCH ₃ (acetylacetone).

Next, a chemically amplified resist is applied to the surface of the semiconductor substrate 1 and then exposed using a desired mask, and then PEB and development are sequentially performed to form a pattern.

When the pattern is formed as described above,
As shown in FIG. 4, the hardly soluble layer is not formed on the surface portion of the resist pattern 5. That is, FIG. 4 shows the semiconductor substrate 1.
A positive chemically amplified resist (KRF K2G, manufactured by Japan Synthetic Rubber Co., Ltd.) was applied on the above to a film thickness of 0.7 μm, and then exposed by a KrF excimer laser stepper with NA: 0.5, and then PEB was applied. The cross-sectional shape of the resist pattern 5 of 0.25 μm line-and-space is shown when the development is carried out at a temperature of 100 ° C. for 90 seconds and the development is performed using a 2.38 wt% tetramethylammonium hydroxide aqueous solution.

As described above, according to the second reference mode,
Since 4-trimethylsiloxy-3-penten-2-one is used as the surface treatment agent, the surface of the semiconductor substrate 1 can be made hydrophobic without generating ammonia, so that the surface portion of the resist pattern 5 is difficult. It is possible to prevent the formation of a solubilized layer and obtain a resist pattern having a stable shape.

( One Embodiment) Hereinafter, a pattern forming method according to one embodiment of the present invention will be described with reference to FIGS.

[0050] Figure 5 shows a process flow of the pattern forming method according to an embodiment, FIG. 6 shows the surface state of the semiconductor substrate when subjected to surface treatment with a surface treatment agent according to one embodiment, FIG. 7 1 shows a schematic cross-sectional shape of a pattern formed on a semiconductor substrate that has been surface-treated with a surface-treating agent according to an embodiment.

First, as shown in FIG. 6 (a), 4-dimethyl-n-hexylsiloxy-3-, represented by the following [Chemical Formula 8], is used as a surface treatment agent on the surface of the semiconductor substrate 1 made of silicon. Penten-2-one was fed (ie 4-dimethyl-n-hexylsiloxy-3-penten-2-one was bubbled with nitrogen gas, 90 ° C.
The surface of the semiconductor substrate 1 is made hydrophobic by spraying on the surface of the semiconductor substrate heated for 30 seconds) to improve the adhesion of the semiconductor substrate 1.

[0052]

[Chemical 8]

By doing so, as shown in FIG. 6B, H of the OH group on the surface of the semiconductor substrate 1 is changed to Si (CH ₃ ).
₂ (CH ₂₎ is replaced by the ₅ CH ₃ (dimethyl -n- hexyl silyl _{group), CH 3 COCH 2 COCH 3} ( acetylacetone) is generated.

Next, a chemically amplified resist is applied to the surface of the semiconductor substrate 1 and then exposed using a desired mask, and then PEB and development are sequentially performed to form a pattern.

When the pattern is formed as described above,
As shown in FIG. 7, the sparingly soluble layer is not formed on the surface portion of the resist pattern 6. That is, FIG. 7 shows the semiconductor substrate 1
A positive chemically amplified resist (KRF K2G, manufactured by Japan Synthetic Rubber Co., Ltd.) was applied on the above to a film thickness of 0.7 μm, and then exposed by a KrF excimer laser stepper with NA: 0.5, and then PEB was applied. The cross-sectional shape of the resist pattern 6 having a line and space of 0.25 μm is shown when the development is carried out at a temperature of 100 ° C. for 90 seconds and the development is performed using a 2.38 wt% tetramethylammonium hydroxide aqueous solution.

As described above, according to one embodiment, 4-dimethyl-n-hexylsiloxy-3 is used as the surface treatment agent.
Since penten-2-one is used, the surface of the semiconductor substrate 1 can be made hydrophobic without generating ammonia, so that it is possible to prevent the formation of the hardly soluble layer on the surface portion of the resist pattern, A stable resist pattern shape can be obtained.

As the surface treatment agent, the first or second reference
In the embodiment, 4-trimethylsiloxy-3-penten-2-one was used, and in one embodiment, 4-dimethyl-n-hexylsiloxy-3-penten-2-one was used. Is not limited to these. That is, a surface treatment agent containing a silane compound represented by the following general formula (1) can be used.

[0058]

[Chemical 9]

However, R ¹ , R ² and R ³ are the same or different and are a hydrogen atom, a substituted saturated hydrocarbon group having 1 to 6 carbon atoms or an unsubstituted saturated hydrocarbon group, and 1 to 6 carbon atoms. A substituted unsaturated hydrocarbon group or an unsubstituted unsaturated hydrocarbon group, or an alicyclic saturated hydrocarbon group having 3 to 6 carbon atoms, R ⁴ ,
R ⁵ and R ⁶ are the same or different and are a hydrogen atom or OR.
⁷ (R ⁷ is a hydrogen atom, a substituted saturated hydrocarbon group having 1 to 6 carbon atoms or an unsubstituted saturated hydrocarbon group, a substituted unsaturated hydrocarbon group having 1 to 6 carbon atoms or an unsubstituted unsaturated hydrocarbon group,
Alternatively, it is an alicyclic saturated hydrocarbon group having 3 to 6 carbon atoms. ) A substituted saturated hydrocarbon group or an unsubstituted saturated hydrocarbon group having 1 to 6 carbon atoms, a substituted unsaturated hydrocarbon group or an unsubstituted unsaturated hydrocarbon group having 1 to 6 carbon atoms, or an alicyclic ring having 3 to 6 carbon atoms Formula is a saturated hydrocarbon group.

Other examples of the silane compound represented by the above general formula (1) include compounds represented by the following [Chemical formula 10], [Chemical formula 11] and [Chemical formula 12].

[0061]

[Chemical 10]

[0062]

[Chemical 11]

[0063]

[Chemical 12]

In [Chemical Formula 10], [Chemical Formula 11] and [Chemical Formula 12], (c) is 3-dimethyl (3 ', 4', 4'-trifluoro-3'-butenyl) siloxytrifluoromethyl-2. -Propen-1-trifluoromethyl-1-one, (e) is 4-dimethylcyclohexylsiloxy-
3-penten-2-one, (j) is 4-t-butyldimethylsiloxy-3-penten-2-one,
(K) is 2-isopropyldimethylsiloxy-1-methoxycarbonyl-1-propene.

When the surface treatment of the surface of the semiconductor substrate with the surface treatment agent containing the silane compound represented by the general formula (1), the surface of the semiconductor substrate becomes hydrophobic,
Adhesion between the semiconductor substrate and the resist pattern is improved.

Further, since the alkaline component is not generated on the surface of the semiconductor substrate after the surface treatment, the acid generated from the chemically amplified resist by exposure does not react with the alkaline component. It is possible to obtain a resist pattern having a stable shape in which the hardly soluble layer is not formed.

In the general formula (1), when at least one of R ¹ , R ² and R ³ has 3 or more carbon atoms, it is present on the surface of the semiconductor substrate when the surface treatment is performed. Since a space composed of a hydrocarbon group layer is formed between the atom having the lone electron pair and the resist, the hydrophobicity of the surface of the semiconductor substrate is further improved.

Due to the improvement of the hydrophobicity of the semiconductor substrate and the hydrocarbon group layer formed on the surface of the semiconductor substrate as described above, the acid generated from the resist and the isolation of the surface of the semiconductor substrate when the chemically amplified resist is used. Since it becomes difficult to react with the electron pair, deactivation of the acid generated from the chemically amplified resist is prevented, so that it is possible to prevent the bottoming portion of the resist pattern from being formed. Incidentally, examples of the semiconductor substrate in this case include a BPSG film, a TiN film, and a Si.
An N film etc. are mentioned.

Further, in the second reference embodiment and one embodiment, as the chemically amplified resist, a two component type chemically amplified positive resist containing an acid generator and a resin which becomes alkali-soluble by the action of an acid ( KRF K2G) was used, but the present invention is not limited thereto, and a three-component chemically amplified positive resist containing an acid generator, an alkali-soluble resin, and a compound or resin that becomes alkali-soluble by the action of an acid, or A three-component chemically amplified negative resist containing an acid generator, an alkali-soluble resin, and a compound or resin that causes a crosslinking reaction by the action of an acid can be widely used. Examples of commercially available two-component chemically amplified positive resists include TDUR-DP manufactured by Tokyo Ohka Co., Ltd.
Examples of commercially available three-component chemically amplified positive resists include DX561 and DX9 manufactured by Hoechst.
81, and examples of commercially available 3-component chemically amplified negative resists include XP-884 manufactured by Shipley Co., Ltd.
3, SAL-601 and the like.

Since the chemically amplified resist is affected by the alkaline component regardless of its constitution or constituent components, the second reference embodiment and one embodiment are applicable to all chemically amplified resists and all exposure light. (KrF, Ar
It is effective for chemically amplified resists applied to F, DUV, EUV, X-ray, EB, etc.).

Examples of the constituent components of the above chemically amplified resist are given below, but the constituent components are not limited to the following.

<Two-Component Chemically Amplified Positive Resist> Resin that becomes alkali-soluble by the action of acid: poly (t-butoxycarbonyloxystyrene-co-hydroxystyrene) poly (t-butoxycarbonylmethyloxystyrene) -co-
Hydroxystyrene) Poly (tetrahydropyranyloxystyrene-co-hydroxystyrene) Poly (2-methyl-2-adamantylmethacrylate-co-3-
Oxocyclohexyl methacrylate) ○ Acid generator …… Onium salt, nitrobenzyl sulfonate compound <Three-component chemical amplification positive resist> ○ Alkali-soluble resin …… Polyvinylphenol, polymethacrylic acid ○ Alkali-soluble by the action of acid Resin or compound that becomes ... Poly (t-butoxycarbonyloxystyrene-co-hydroxystyrene) Poly (t-butoxycarbonylmethyloxystyrene-co-
Hydroxystyrene) Poly (tetrahydropyranyloxystyrene-co-hydroxystyrene) Compound shown in [Chemical Formula 13] below: Acid generator: onium salt, nitrobenzyl sulfonate compound

[0073]

[Chemical 13]

[0074] Hereinafter, the above-mentioned [Chemical Formula 10], using a silane compound represented by Formula 11] and [Chemical Formula 12], the
Experiments similar to those of the first and second reference embodiments and the embodiment were performed, and favorable results were obtained as shown in [Table 1], [Table 2] and [Table 3] below.

[0075]

[Table 1]

[0076]

[Table 2]

[0077]

[Table 3]

[0078]

According to the pattern forming method of the present invention, the surface of the semiconductor substrate is treated with the surface treatment agent containing the silane compound represented by the general formula (1). Adhesion is improved. That is, since the energy level of the electrophilic orbit of the silane compound is low, the reactivity of the trimethylsilyl group of the silane compound with the silanol group on the semiconductor substrate is high. For this reason, since many silyl groups of the silane compound adhere to the surface of the semiconductor substrate, the surface of the semiconductor substrate becomes hydrophobic, the adhesion between the semiconductor substrate and the resist pattern is greatly improved, and the film does not peel off. A reliable resist pattern can be obtained.

In the pattern forming method according to the present invention,
When the resist in the second step is a two-component chemically amplified resist, a three-component chemically amplified positive resist, or a three-component chemically amplified negative resist, the surface of the semiconductor substrate is represented by the general formula (1). Since the surface treatment is performed with the surface treatment agent containing the silane compound represented by, no alkali component is generated on the surface of the semiconductor substrate after the surface treatment. Therefore, the acid generated from the chemically amplified resist by exposure is
Since it does not react with the alkaline component, it is possible to obtain a stable-shaped resist pattern in which the hardly soluble layer is not formed on the surface.

Further, conventionally, during the period from exposure to PEB, the acid generated in the chemically amplified resist by exposure generates an alkali component such as HMDS. There is a problem that the insoluble layer is formed on the surface of the resist pattern as a result of being deactivated upon receipt of the chemical amplification type resist according to the pattern forming method of the present invention during exposure from exposure to PEB. Since no alkaline component is present on the surface of the resist, the acid generated in the chemically amplified resist by exposure is not deactivated, and a resist pattern having a more stable shape in which the surface hardly soluble layer is not formed can be obtained.

In the pattern forming method according to the present invention,
When the resist in the second step is a normal resist having a naphthoquinonediazide compound and a novolac resin,
Adhesion between the semiconductor substrate and the resist pattern is improved when a normal resist is used.

According to the surface treatment agent of the present invention, the adhesiveness between the semiconductor substrate and the resist pattern is improved, so that the film does not peel off regardless of whether the resist is a chemically amplified resist or a non-chemically amplified resist. An excellent resist pattern can be obtained, and particularly when a chemically amplified resist is used, deactivation of the acid generated from the chemically amplified resist by exposure is surely prevented to obtain an excellent resist pattern. You can

[Brief description of drawings]

FIG. 1 is a flowchart illustrating a process of a pattern forming method according to a first reference embodiment of the present invention.

[2] In the pattern forming method according to the first referential embodiment, 4-trimethylsiloxy-3-penten-2
It is a schematic diagram which shows the surface state of a semiconductor substrate when ON is supplied.

FIG. 3 is a schematic view showing a cross-sectional shape of a resist pattern formed by the pattern forming method according to the first reference embodiment.

FIG. 4 is a schematic diagram showing a cross-sectional shape of a resist pattern formed by a pattern forming method according to a second reference embodiment of the present invention.

FIG. 5 is a flowchart illustrating a process of a pattern forming method according to an embodiment of the present invention.

FIG. 6 is a schematic view showing a surface state of a semiconductor substrate when 4-dimethyl-n-hexylsiloxy-3-penten-2-one is supplied in the pattern forming method according to the one embodiment.

FIG. 7 is a schematic view showing a cross-sectional shape of a resist pattern formed by the pattern forming method according to the one embodiment.

FIG. 8 is a flowchart illustrating a process of a pattern forming method according to a second conventional example.

FIG. 9 is a schematic diagram showing a surface state of a semiconductor substrate when HMDS is supplied in a pattern forming method according to a second conventional example.

FIG. 10 is a schematic diagram showing a cross-sectional shape of a resist pattern formed by a pattern forming method according to a second conventional example.

FIG. 11 is a diagram showing the correlation between the environmental concentration of trimethylsilanol, which is a decomposition product of HMDS, and the environmental concentration of ammonia.

[Explanation of symbols]

1 Semiconductor substrate made of silicon 2 resist pattern 3 Insoluble layer 4 Resist pattern 5 resist pattern 6 resist pattern

─────────────────────────────────────────────────── ───Continuation of front page (56) Reference JP-A-7-335603 (JP, A) JP-A-7-120919 (JP, A) JP-A-9-218516 (JP, A) JP-A-9- 102458 (JP, A) Special table H11-511900 (JP, A) International publication 96/15861 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/027 G03F 7 / 00-7/42

Claims (6)

(57) [Claims] 1. The surface of a semiconductor substrate is represented by the following general formula (1):
A first step of performing a surface treatment with a surface treatment agent containing a silane compound; a second step of applying a resist to the surface of the surface-treated semiconductor substrate to form a resist film; On the other hand, a third step of forming a resist pattern by performing development after exposing using a mask having a desired pattern shape. [Chemical 1] (However, R ¹ , R ² , and R ³ are the same or different and are a hydrogen atom, a substituted saturated hydrocarbon group having 1 to 6 carbon atoms or an unsubstituted saturated hydrocarbon group, and a substituted unsubstituted hydrocarbon group having 1 to 6 carbon atoms. It is a saturated hydrocarbon group or an unsubstituted unsaturated hydrocarbon group, or an alicyclic saturated hydrocarbon group having 3 to 6 carbon atoms, and at least one of R ¹ , R ² and R ³ has a carbon number of
3 or more, R ⁴ , R ⁵ and R ⁶ are the same or different and are a hydrogen atom, OR ⁷ (R ⁷ is a hydrogen atom, a substituted saturated hydrocarbon group having 1 to 6 carbon atoms or an unsubstituted saturated group) Hydrocarbon group, carbon number 1-6
Is a substituted unsaturated hydrocarbon group or an unsubstituted unsaturated hydrocarbon group, or an alicyclic saturated hydrocarbon group having 3 to 6 carbon atoms. ) C1-6 substituted saturated hydrocarbon group or unsubstituted saturated hydrocarbon group, C1-6 substituted unsaturated hydrocarbon group or unsubstituted unsaturated hydrocarbon group, or C3-6 alicyclic Formula is a saturated hydrocarbon group. ) 2. The pattern according to claim 1, wherein the resist in the second step is a chemically amplified resist containing an acid generator and a resin which becomes alkali-soluble by the action of acid. Forming method. 3. The resist in the second step is a chemically amplified resist containing an acid generator, an alkali-soluble resin, and a compound or resin which becomes alkali-soluble by the action of an acid. The pattern forming method according to claim 1. 4. The resist in the second step is a chemically amplified resist containing an acid generator, an alkali-soluble resin, and a compound or resin that causes a crosslinking reaction by the action of an acid. The pattern forming method according to claim 1. 5. The pattern forming method according to claim 1, wherein the resist in the second step contains a naphthoquinonediazide compound and a novolac resin. 6. A surface treating agent for treating the surface of a semiconductor substrate, comprising a silane compound represented by the following general formula (1). [Chemical 2] (However, R ¹ , R ² , and R ³ are the same or different and are a hydrogen atom, a substituted saturated hydrocarbon group having 1 to 6 carbon atoms or an unsubstituted saturated hydrocarbon group, and a substituted unsubstituted hydrocarbon group having 1 to 6 carbon atoms. It is a saturated hydrocarbon group or an unsubstituted unsaturated hydrocarbon group, or an alicyclic saturated hydrocarbon group having 3 to 6 carbon atoms, and at least one of R ¹ , R ² and R ³ has a carbon number of
3 or more, R ⁴ , R ⁵ and R ⁶ are the same or different and are a hydrogen atom, OR ⁷ (R ⁷ is a hydrogen atom, a substituted saturated hydrocarbon group having 1 to 6 carbon atoms or an unsubstituted saturated group) Hydrocarbon group, carbon number 1-6
Is a substituted unsaturated hydrocarbon group or an unsubstituted unsaturated hydrocarbon group, or an alicyclic saturated hydrocarbon group having 3 to 6 carbon atoms. ) A substituted saturated hydrocarbon group having 1 to 6 carbon atoms or an unsubstituted saturated hydrocarbon group, a substituted unsaturated hydrocarbon group having 1 to 6 carbon atoms or an unsubstituted unsaturated hydrocarbon group, or an alicyclic ring having 3 to 6 carbon atoms Formula is a saturated hydrocarbon group. )