JP5663140B2 - Coating pattern forming method, resist coating film forming material, pattern forming method - Google Patents

Description

  The present invention relates to a coating pattern forming method, a resist coating film forming material used in the method, and a pattern forming method using the coating pattern forming method.

A technology (pattern formation technology) that forms a fine pattern on a substrate and processes the lower layer of the pattern by etching using this as a mask has been widely adopted for IC creation in the semiconductor industry, and has received great attention. ing. The pattern formation technology has made rapid progress with the high integration of semiconductor devices, but there is a demand for higher pattern density.
In order to increase the density of fine patterns, one of the pattern forming techniques that has been proposed in recent years is a spacer patterning technology. For example, in Non-Patent Document 1, FIG. 1 (b) to (d), a fin-like SiN spacer pattern is formed on the substrate, and the upper portion and both side surfaces of the SiN spacer are formed thereon by CVD (chemical vapor deposition method, also referred to as chemical vapor deposition method). A method of forming a coating (SiO ₂ film) on the substrate and then removing the coating on the top of the SiN spacer and the SiN spacer by dry etching is shown. According to such a method, the coating on both sides of the SiN spacer remains on the substrate. That is, twice as many SiO ₂ patterns as the original SiN spacers remain on the substrate, and a higher density pattern is formed.

B. Degroote et al., “Spacer defined FinFET: Active area patterning of sub-20 nm fins with high density”, Microelectronic Engineering, Vol. 60, 1999, Vol.

However, the method described in Non-Patent Document 1 uses CVD to form a coating (SiO ₂ film) on a pattern (SiN), which requires a large number of processes, takes time, and costs equipment. There are problems such as taking. Therefore, there is a need for a technique that can easily form a pattern (covering pattern) whose surface is coated without using CVD.
The present invention has been made in view of the above circumstances, and a coating pattern forming method capable of easily forming a coating pattern, a material useful for the coating pattern forming method, and a pattern forming method using the coating pattern forming method The purpose is to provide.

In order to achieve the above object, the present invention employs the following configuration.
That is, the first aspect of the present invention is a coating pattern forming method for forming a pattern whose surface is coated with a coating film on a support,
Forming a resist pattern on a support using a resist composition containing an acid generator capable of generating an acid by exposure and / or heat; and
On the support on which the resist pattern is formed, a resist coating film forming material containing a silicon-containing polymer capable of causing a crosslinking reaction by the action of an acid and an organic solvent that dissolves the silicon-containing polymer is applied. Forming a coating film (ii),
Exposing and / or baking the resist pattern to generate an acid in the resist pattern (iii);
A step (iv) of developing the coating film;
Including
The silicon-containing polymer is a silicone resin;
In the coating pattern forming method, the silicone resin has a phenolic hydroxyl group and / or an alcoholic hydroxyl group in a side chain.
The second aspect of the present invention is a coating pattern forming method for forming a pattern whose surface is coated with a coating film on a support,
Forming a resist pattern on a support using a resist composition containing an acid generator capable of generating an acid by exposure and / or heat; and
On the support on which the resist pattern is formed, a resist coating film forming material containing a silicon-containing polymer capable of causing a crosslinking reaction by the action of an acid and an organic solvent that dissolves the silicon-containing polymer is applied. Forming a coating film (ii),
Exposing and / or baking the resist pattern to generate an acid in the resist pattern (iii);
A step (iv) of developing the coating film;
Including
The silicon-containing polymer is a silicone resin;
The silicone resin has an epoxy group-containing group and / or an ethylenically unsaturated double bond-containing group in a side chain and a hydrogen atom directly bonded to a silicon atom. .
According to a third aspect of the present invention, there is provided a step (i) of forming a resist pattern on a support using a resist composition containing an acid generator capable of generating an acid by exposure and / or heat, and the resist A resist coating film forming material containing a silicon-containing polymer capable of causing a crosslinking reaction by the action of an acid and an organic solvent that dissolves the silicon-containing polymer is applied onto the support on which the pattern is formed. A step (ii) of forming a film, a step (iii) of exposing and / or baking the resist pattern to generate an acid in the resist pattern, and a step of developing the coating film And (iv), a resist coating film forming material used in a coating pattern forming method for forming on a support a pattern whose surface is coated with a coating film,
Containing a silicon-containing polymer capable of causing a crosslinking reaction by the action of an acid, and an organic solvent for dissolving the silicon-containing polymer,
The silicon-containing polymer is a silicone resin;
The silicone resin has a phenolic hydroxyl group and / or an alcoholic hydroxyl group in a side chain.
A fourth aspect of the present invention is a pattern forming method including a step of performing an etching process on a support on which a coating pattern is formed by the coating pattern forming method of the first aspect or the second aspect.

In the present specification and claims, “aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.
The “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified.
Unless otherwise specified, the “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group.
“Structural unit” means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
“Exposure” is a concept including general irradiation of radiation.

  According to the present invention, a coating pattern forming method capable of easily forming a coating pattern, materials useful for the coating pattern forming method (resist coating film forming material and resist composition), and the coating pattern forming method are used. A pattern forming method can be provided.

It is a schematic process drawing explaining preferable embodiment of the coating pattern formation method of this invention. It is a schematic sectional drawing explaining the case where the whole coating film hardens | cures. It is a schematic process drawing explaining preferable embodiment of the pattern formation method of this invention.

≪Coating pattern formation method≫
The coating pattern forming method of the present invention is a coating pattern forming method in which a pattern whose surface is coated with a coating film is formed on a support, and an acid is generated on the support by exposure and / or heat. A step (i) of forming a resist pattern using a resist composition containing an acid generator to be obtained, and a silicon-containing polymer capable of causing a crosslinking reaction by the action of an acid on the support on which the resist pattern is formed; Applying a resist coating film forming material containing an organic solvent that dissolves the silicon-containing polymer to form a coating film (ii), and exposing and / or baking the resist pattern; A step (iii) of generating an acid in the resist pattern, and a step (iv) of developing the coating film.
Hereinafter, preferred embodiments of the coating pattern forming method of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic process diagram showing a first embodiment of the coating pattern forming method of the present invention.
In this embodiment, first, as shown in FIG. 1A, a resist pattern 2 having a height h is formed on one main surface 1a of the support 1 using a resist composition containing an acid generator. Is formed (step (i)).
Next, as shown in FIG.1 (b), the coating material 3 is formed by apply | coating a specific resist coating film forming material on the support body 1 in which the resist pattern 2 was formed (process (ii)). ). As a result, the gaps between the plurality of resist patterns 2 are filled with the resist coating film forming material. Further, in the illustrated example, the coating film 3 is formed with a film thickness larger than the height h of the resist pattern 2, whereby the upper surface of the resist pattern 2 is also covered with the resist coating film forming material.

Next, the resist pattern 2 is exposed and / or baked to generate an acid in the resist pattern 2 (step (iii)). Since the coating film 3 in contact with the resist pattern 2 contains a silicon-containing polymer capable of causing a crosslinking reaction by the action of an acid, when an acid is generated in the resist pattern 2, the part of the resist pattern 2 that is in contact with the resist pattern 2 by the action of the acid. As a result, a cured film (resist coating film 4) is formed on the surface of the resist pattern 2 as shown in FIG. 1 (c).
In the case of using a conventional method, for example, CVD, a similar coating film is formed not only on the resist pattern surface but also on the support surface when forming the coating film. A coating film can be formed only on the surface. Therefore, the coating film is useful as an etching mask for etching the support, as shown in a pattern forming method described later.

Next, the coating film 3 is developed (step (iv)).
After the step (iii), the portion of the coating film 3 that has been cured to become the resist coating film 4 and the uncured (uncrosslinked) portion are dissolved in an alkali or an organic solvent due to a difference in molecular weight or the like. Sex is different. For this reason, when the developing process is performed using a fluid that hardly dissolves the resist coating film 4 and easily dissolves the uncured portion as a developing solution, the uncured portion of the coating film 3 is removed while the resist coating film 4 is removed. The covering film 4 remains without being removed. As a result, as shown in FIG. 1 (d), a coating pattern 7 including a resist pattern 2 and a resist coating film 4 that covers the surface of the resist pattern 2 is formed on the support 1.

Hereinafter, steps (i) to (iv) will be described in more detail.
[Step (i)]
The support 1 is not particularly limited, and a conventionally known one can be used. For example, a substrate for an electronic component or a substrate on which a predetermined wiring pattern is formed can be exemplified. More specifically, a silicon substrate, a metal substrate such as copper, chromium, iron, and aluminum, a glass substrate, and the like can be given. As a material for the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
Moreover, as a support body, the lower layer film | membrane may be provided on the above substrates. The lower layer film is not particularly limited, and a known layer can be used as a layer provided under the resist film, and may be an inorganic film or an organic film. May be. An inorganic antireflection film (inorganic BARC) is an example of the inorganic film. Examples of the organic film include an organic antireflection film (organic BARC) and a lower layer film in a multilayer resist method. In particular, it is preferable to provide an organic film because a pattern with a high aspect ratio can be formed on the substrate, which is useful in manufacturing semiconductors.
Here, the multilayer resist method is a method in which at least one organic film (lower film) and at least one resist film are provided on a substrate, and the lower layer is patterned using the resist pattern formed on the upper resist film as a mask. It is said that a high aspect ratio pattern can be formed. In the multilayer resist method, basically, a method having a two-layer structure of an upper layer resist film and a lower layer film, and one or more intermediate layers (metal thin film, etc.) are provided between these resist film and lower layer film. It is divided into a method of providing a multilayer structure of three or more layers provided. According to the multilayer resist method, by securing a required thickness with the lower layer film, the resist film can be thinned and a fine pattern with a high aspect ratio can be formed.
The inorganic film can be formed, for example, by applying an inorganic antireflective film composition such as a silicon-based material on a substrate and baking it.
The organic film is formed by, for example, applying an organic film forming material in which a resin component or the like constituting the film is dissolved in an organic solvent to a substrate with a spinner or the like, preferably 200 to 300 ° C., preferably 30 to 300 seconds, More preferably, it can be formed by baking under heating conditions of 60 to 180 seconds.
The organic film forming material for forming the organic film is not particularly limited, and a resist or resin generally used in manufacturing a semiconductor element or a liquid crystal display element can be used. However, the organic film forming material does not necessarily require sensitivity to an electron beam or light like a resist film.
In the pattern forming method of the present invention to be described later, the organic film forming material may be a material capable of forming an organic film that can be etched, particularly dry-etched, so that the lower layer film can be etched using the coating pattern as an etching mask. preferable. Among these, a material capable of forming an organic film capable of etching such as oxygen plasma etching is preferable.
As the lower layer film, an organic film is preferable since it has an excellent etching selectivity with the material constituting the coating pattern. In addition, when an organic film is provided as a lower layer film, a high aspect ratio pattern can be easily formed on a substrate as described above, which is preferable because it is useful in manufacturing semiconductors.

In the step (i), in order to form the resist pattern 2 on one main surface 1a of the support 1, an acid generator that can generate an acid by exposure and / or heat (hereinafter referred to as component (B)). A resist composition containing is used.
As this resist composition, what was mix | blended (B) component among the resist compositions proposed so far can be utilized. Moreover, you may mix | blend and use the (B) component in the resist composition which is not mix | blended (B) component.
An example of the former is a chemically amplified resist composition. As an example of the latter, a non-chemically amplified resist composition can be given.
In the present invention, a chemically amplified resist composition is preferably used as the resist composition because it is particularly excellent in sensitivity, resolution and the like.

As a method of forming the resist pattern 2 on one main surface 1a of the support 1, a conventionally known method can be used. For example, a resist pattern is formed by a method including a step of forming a resist film on a support using the resist composition, a step of exposing the resist film, and a step of developing the resist film to form a resist pattern. it can.
What is necessary is just to set suitably the specific conditions at the time of this resist pattern formation according to the kind of resist composition to be used.
As a specific example, when a chemically amplified resist composition is used, for example, the resist pattern forming method can be performed as follows. That is, first, the resist composition is applied onto the support 1 with a spinner or the like, and pre-baked (post-apply bake (PAB)) for 40 to 120 seconds, preferably 60 to 90 seconds under a temperature condition of 80 to 150 ° C. To form a resist film, for example, using an exposure apparatus such as an ArF exposure apparatus, an electron beam drawing apparatus, an EUV exposure apparatus, or the like, through a photomask (mask pattern) on which a predetermined pattern is formed, or After selective exposure by drawing or the like by direct irradiation with an electron beam without passing through a mask pattern, PEB (post-exposure heating) is applied for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150 ° C. Subsequently, this is developed using an alkali developer, for example, an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH), preferably rinsed with pure water and dried. In some cases, a baking process (post-bake) may be performed after the development process. In this way, the resist pattern 2 can be obtained.

The film thickness of the resist film is not particularly limited, and can be appropriately selected in consideration of the target dimension of the resist pattern to be formed.
The film thickness is preferably 150 nm or less, more preferably 120 nm or less, and even more preferably 100 nm or less because a fine resist pattern (for example, a resist pattern having a dimension of 100 nm or less) can be easily formed and the effectiveness of the present invention is high.
Although the minimum of this film thickness is not specifically limited, Preferably it is 50 nm or more. When the film thickness is 50 nm or more, the pattern reversal coating 4 is used as an etching mask for etching the resist pattern 2, and when the support 1 is provided with a lower film, the lower film is etched. The film can be formed with a film thickness sufficient to function as an etching mask.

The wavelength used for the exposure is not particularly limited, and ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. Can be done using radiation. When a chemically amplified resist composition is used, among these, KrF excimer laser, ArF excimer laser, EB or EUV is preferably used.

The exposure may be performed by normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be performed by immersion exposure.
In immersion exposure, a solvent (immersion medium) having a refractive index larger than the refractive index of air is applied to a portion between a lens and a resist film on the wafer, which is conventionally filled with an inert gas such as air or nitrogen. This is a method of performing exposure in a state where
More specifically, the immersion exposure is a solvent (immersion medium) having a refractive index larger than the refractive index of air between the resist film obtained as described above and the lowermost lens of the exposure apparatus. And in that state, exposure (immersion exposure) is performed through a desired photomask.
As the immersion medium, a solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film exposed by the immersion exposure is preferable. The refractive index of such a solvent is not particularly limited as long as it is within the above range.
Examples of the solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film include water, a fluorine-based inert liquid, a silicon-based solvent, and a hydrocarbon-based solvent.
Specific examples of the fluorine-based inert liquid include a fluorine-based compound such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , and C ₅ H ₃ F ₇ as a main component. Examples thereof include liquids, and those having a boiling point of 70 to 180 ° C are preferable, and those having a boiling point of 80 to 160 ° C are more preferable. It is preferable that the fluorine-based inert liquid has a boiling point in the above range since the medium used for immersion can be removed by a simple method after the exposure is completed.
As the fluorine-based inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms is particularly preferable. Specific examples of the perfluoroalkyl compound include a perfluoroalkyl ether compound and a perfluoroalkylamine compound.
More specifically, examples of the perfluoroalkyl ether compound include perfluoro (2-butyl-tetrahydrofuran) (boiling point: 102 ° C.). Examples of the perfluoroalkylamine compound include perfluorotributylamine ( Boiling point of 174 ° C.).

In the present invention, the resist pattern 2 may be formed by a double patterning process. The double patterning process is a method of forming a resist pattern by performing patterning twice or more (for example, “Proceedings of SPIE, 5256, 985-994 (2003).”). , "Proceedings of SPIE, 6153, 615301-1-19 (2006)."). According to the double patterning process, even if a light source having the same exposure wavelength is used as compared with single patterning in which a series of steps (lithography steps) from the formation of the resist film to development is performed once to form a resist pattern, Even if the same resist composition is used, a resist pattern with higher resolution can be formed at a higher density. The double patterning process can be performed using an existing exposure apparatus.
There are several types of double patterning processes. For example, (1) a method of forming a pattern by repeating a lithography step (from application of a resist composition to exposure and development) and an etching step twice or more, and (2) a lithography step And (3) a method of forming a resist pattern after forming a resist film by performing selective exposure to the resist film twice or more and developing it (multiple exposure method). Among these, (2) or (3) is preferable, and (2) is particularly preferable.

In the formation of the resist pattern by the double patterning process of (2), for example, a first resist composition is applied on a support to form a first resist film, and the first resist film is selectively formed. A step of exposing and alkali developing to form a first resist pattern (first patterning step);
On the support on which the first resist pattern is formed, a second resist composition is applied to form a second resist film, the second resist film is selectively exposed, and alkali development is performed. And a step of forming a second resist pattern (second patterning step);
It can implement by the method of including.
According to this method, a resist pattern composed of the first resist pattern and the second resist pattern is formed on the support.

Specifically, the first patterning step and the second patterning step are respectively performed in the same manner as in the case where “the resist pattern 2 is formed on one main surface 1a of the support 1” described above. Can be implemented.
Each of the first resist composition and the second resist composition used in each step may be a positive type or a negative type.
In the second patterning step, it is preferable that the thickness of the second resist film is at least equal to or higher than the height of the first resist pattern. That is, when the support 1 is viewed from the second resist film side, the surface is preferably flat.
The selective exposure of the second resist film is performed so that the second resist pattern is formed at a position different from the position where the first resist pattern is formed.
Such selective exposure can be performed, for example, by using a photomask different from the photomask used in the first patterning step as the photomask in the second patterning step. In addition, when using a positive type as each of the first resist composition and the second resist composition, or when using a negative type, respectively, for example, the position of the photomask used in the first patterning step is set. It can also be implemented by slightly shifting and using this as the photomask 22 in the second patterning step.

Thus, in the second patterning step, by performing selective exposure so that the position of the second resist pattern and the position of the first resist pattern do not overlap at all, the pattern is more effective than the first resist pattern. A narrow pitch resist pattern having a narrow interval (pitch) is obtained.
For example, in the case of forming a line and space resist pattern, for example, in the first patterning step, a line and space resist pattern is used by using a line and space photomask in which a plurality of lines are arranged at a constant pitch. In the second patterning step, the line pattern is formed at an intermediate position between the line pattern and the line pattern formed in the first patterning step. A line-and-space resist pattern (dense pattern) arranged in a narrower pitch than the (pattern) is formed. The “sparse pattern” is preferably a line and space pattern having a line width: space width = 1: 2 or larger in the line and space resist pattern.
However, the present invention is not limited to this, and the position of the second resist pattern formed in the second patterning step and the position of the first resist pattern formed in the first patterning step partially overlap. Also good.
Further, in the second patterning step, the photomask used in the first patterning step is used as a photomask by rotating, or a photomask having a different pattern from the photomask (for example, the first patterning step). And the like using a photomask having a line and space pattern and a hole mask pattern in the second patterning step).

  In the double patterning process, after the second patterning step, the same patterning step as the second patterning step may be repeated a plurality of times. That is, on the support on which the resist pattern is formed in the second patterning step, a resist composition is applied to form a resist film, and the resist film is selectively exposed and developed to form a resist pattern. The operation to be performed may be performed a plurality of times. Thereby, a denser pattern with a narrower pitch or a pattern with a complicated shape can be formed.

In the present embodiment, in the example of FIG. 1A, the cross-sectional shape of the resist pattern 2 is schematically illustrated as a rectangular shape whose side is perpendicular to the main surface 1a and whose upper part is parallel to the main surface 1a. However, the present invention is not limited to this, and the upper part of the resist pattern 2 may be rounded or the side part may be inclined in a tapered shape.
The width w and interval s of the resist pattern 2 are not particularly limited.
In the present invention, since a coating pattern is formed by utilizing a crosslinking reaction by the action of an acid, it can be applied to a resist pattern 2 having a width w of about several tens of nm, and may be several μm.
The ratio of w / s can also be set as appropriate according to the purpose of use of the coating pattern. In an embodiment of the pattern forming method to be described later, it is preferable that w / s = 1/3.

[Step (ii)]
In step (ii), a resist coating film containing a silicon-containing polymer capable of causing a crosslinking reaction by the action of an acid and an organic solvent that dissolves the silicon-containing polymer on the support 1 on which the resist pattern 2 is formed A coating material 3 is formed by applying a forming material.
The composition of the resist coating film forming material will be described in detail later.
The method for applying the resist coating film forming material onto the support 1 is not particularly limited, and known means such as a spinner, a coater, a dispenser and the like can be used.
The application may be performed so that the coating film 3 having a desired film thickness can be formed.
In the present embodiment, the coating film 3 is formed with a film thickness that is thicker than the height of the resist pattern 2. The difference between the film thickness of the coating film 3 and the height of the resist pattern 2 ([film thickness of the coating film 3]-[height of the resist pattern 2]) is the upper surface of the resist pattern 2 by the pattern forming method described later. Considering ease of exposure when the resist film 2 is exposed by removing a portion of the coating film by etching or the like, 1 to 40 nm is preferable, and 1 to 30 nm is more preferable.
The application is performed so that at least the resist pattern 2 in the region where the coating pattern 7 is to be formed is covered with the coating film 3. At this time, you may carry out so that the whole main surface of the support body 1 may be covered with the coating film 3, and you may carry out so that a part on this main surface may be covered. For example, application to a region where the resist pattern 2 is not formed may be omitted.

  After application, in some cases (for example, when only exposure is performed in the next step (iii) and baking is not performed), a baking process (pre-baking process) for the purpose of drying the coating (solvent volatilization) may be performed. Good. In this case, the baking process is performed at a temperature at which no acid is generated from the component (B) in the resist pattern 2.

[Step (iii)]
In step (iii), the exposure and / or baking may be performed by generating an acid from the component (B) in the resist pattern 2 and crosslinking the silicon-containing polymer in the coating film 3 by the action of the acid. Of baking, only exposure may be performed, only baking may be performed, or both may be performed.
The exposure to the resist pattern 2 can be carried out, for example, by exposing the resist pattern 2 from the coating film 3 side using a transparent material for the exposure light source as a resist coating film forming material for forming the coating film 3. . Moreover, when using the thing transparent to an exposure light source as the support body 1, it can implement also by exposing from the support body 1 side.
The resist pattern 2 may be baked from the support 1 side, from the coating film 3 side, or from both sides.
When baking is performed only from the support 1 side, the support 1 is preferably made of a material having thermal conductivity. As a material having thermal conductivity, an organic material can be selected as long as it has necessary thermal conductivity, but an inorganic material is preferable. Specific examples include semiconductors such as silicon (Si) and germanium, metals such as copper, chromium, iron and aluminum, and silicon compounds such as SiO ₂ , SiO _x N _y and SiN _y .

The exposure and / or baking processing conditions (exposure amount, baking temperature, processing time, etc.) in step (iii) are as follows. Acid is generated from the component (B) in the resist pattern 2, and the coating film 3 is activated by the action of the acid. In order to form the resist coating film 4 by crosslinking the silicon-containing polymer, it is appropriately set in consideration of the type of the component (B) to be used, the exposure light source, the resist pattern dimension, the film thickness, and the like. Specifically, for example, the resist pattern forming method of the present invention is carried out by appropriately changing the exposure and / or baking conditions as appropriate, and the conditions for forming the coating film may be obtained.
The processing conditions in the case of baking are not particularly limited, but are usually 60 to 160 ° C. and about 5 to 150 seconds, preferably 80 to 140 ° C. and 20 to 120 seconds.
The exposure amount may be appropriately set in consideration of each component in the resist composition), the resist pattern dimension, the target dimension of the coating pattern, the exposure apparatus, and the like.

In step (iii), the film thickness of the resist coating film 4 to be formed can be adjusted by adjusting exposure and / or baking processing conditions (exposure amount, baking temperature, processing time, etc.).
Since the crosslinking reaction in the coating film 3 proceeds from the portion in contact with the resist pattern 2, if the processing time is excessive, as shown in FIG. However, by finishing the processing in an appropriate time, only the vicinity of the surface of the resist pattern 2 can be formed as a cured film as shown in FIG.
The processing time varies depending on the exposure amount, baking temperature, the amount of component (B) and the acid generation efficiency, the crosslinking speed of the resist coating film forming material, the ambient temperature during processing, etc. It is easy to obtain the relationship between the desired thickness of the resist coating film 4 and the necessary processing time. Therefore, it is possible to form the resist coating film 4 having a desired thickness by using a processing time determined in advance by preliminary experiments or simulations.

[Step (iv)]
The developer used in step (iv) is one in which a difference (dissolution contrast) occurs in the solubility between the portion of the coating film 3 that has been cured to become the resist coating film 4 and the uncured (uncrosslinked) portion. Specifically, an organic solvent that can dissolve each component contained in the resist coating film forming material (before crosslinking), an alkali developer (alkaline aqueous solution), and the like can be given.
Examples of the organic solvent include organic solvents described in the description of “resist coating film forming material” described later.
A conventionally well-known thing can be utilized as an alkali developing solution, for example, 0.1-10 mass% tetramethylammonium hydroxide (TMAH) aqueous solution is mentioned.
As the developer used in step (iv), an alcohol organic solvent is particularly preferable.
After the development, water rinsing may be performed using pure water or the like.
Further, the surface of the support 1 may be dried by performing a post-bake treatment.

As described above, the coating pattern 7 (pattern in which the surface of the resist pattern 2 is coated with the resist coating film 4) formed on the support 1 can be obtained.
In FIG. 1, the film thickness of the resist coating film 4 is smaller than the width w of the resist pattern 2, but the present invention is not limited to this. For example, the pattern formation of the present invention described later is performed. In the method, as shown in FIG. 3B as the first embodiment, the film thickness of the resist coating film 4 may be equal to the width w of the resist pattern 2 or thicker than the width w of the resist pattern 2. May be.

≪Resist composition≫
The resist composition used in the present invention contains a component (B) (an acid generator capable of generating an acid by exposure and / or heat).
As this resist composition, what was mix | blended (B) component among the resist compositions proposed so far can be utilized. Examples of such resist compositions include chemically amplified resist compositions.
There is no restriction | limiting in particular as a chemically amplified resist composition, It can select suitably from many chemically amplified resist compositions proposed until now and can use it. The chemical amplification resist composition generally contains the component (B) and a base material component (hereinafter referred to as the component (A)) whose solubility in an alkaline developer is changed by the action of an acid. is there.
Here, the “base component” of the resist composition refers to an organic compound having film-forming ability. In general, a base material component (for example, a component (A) described later) is blended in the resist composition in order to form a resist film.
As the base material component, an organic compound having a molecular weight of 500 or more is generally used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved and a nano-level resist pattern is easily formed.
“Organic compounds having a molecular weight of 500 or more” used as the base component are roughly classified into non-polymers and polymers.
As the non-polymer, those having a molecular weight of 500 or more and less than 4000 are usually used. Hereinafter, a nonpolymer having a molecular weight of 500 or more and less than 4000 is referred to as a low molecular compound.
As the polymer, those having a molecular weight of 2000 or more are usually used. Hereinafter, a polymer having a molecular weight of 2000 or more is sometimes simply referred to as “resin”. In the case of a resin, as the “molecular weight”, a mass average molecular weight in terms of polystyrene by GPC (gel permeation chromatography) is used.
Conventionally, a resin is generally used as a base component of a resist composition.
Resist compositions include a positive type in which alkali solubility increases upon exposure and a negative type in which alkali solubility decreases upon exposure. In the present invention, the resist composition may be a positive type or a negative type. A positive resist composition is preferably used.

<(A) component>
When the chemically amplified resist composition is a negative resist composition, as the component (A), a base material component that is soluble in an alkali developer is used, and a crosslinking agent is further blended.
In such a negative resist composition, when an acid is generated from the component (B) by exposure, cross-linking occurs between the base component and the cross-linking agent by the action of the acid, and the base component is in contact with the alkaline developer. It changes from soluble to sparingly soluble. For this reason, when the resist film formed using the negative resist composition is selectively exposed, the exposed portion turns into poorly soluble in the alkali developer, while the unexposed portion is insensitive to the alkali developer. Therefore, only the unexposed portion is removed by alkali development, and a resist pattern is formed.
As the base material component of the negative resist composition, a resin soluble in an alkali developer (alkali-soluble resin) is usually used.
As the alkali-soluble resin, a resin having a unit derived from at least one selected from α- (hydroxyalkyl) acrylic acid or an alkyl ester having 1 to 5 carbon atoms of α- (hydroxyalkyl) acrylic acid, A favorable resist pattern with less swelling can be formed, which is preferable. Α- (Hydroxyalkyl) acrylic acid includes acrylic acid in which a hydrogen atom is bonded to the α-position carbon atom to which the carboxy group is bonded, and a hydroxyalkyl group (preferably having 1 carbon atom) in the α-position carbon atom. One or both of [alpha] -hydroxyalkylacrylic acids to which (5) hydroxyalkyl groups) are attached.
As the crosslinking agent, for example, it is usually preferable to use an amino crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group because a good resist pattern with less swelling can be formed.
It is preferable that the compounding quantity of a crosslinking agent is 1-50 mass parts with respect to 100 mass parts of alkali-soluble resin.

When the chemically amplified resist composition is a positive resist composition, as the component (A), a base material component whose solubility in an alkaline developer is increased by the action of an acid is used.
Such a positive resist composition is poorly soluble in an alkali developer before exposure, and when an acid is generated from the component (B) by exposure, the component (A) is insensitive to the alkali developer by the action of the acid. It turns into soluble. Therefore, in the formation of the resist pattern, when the resist film formed using the positive resist composition is selectively exposed, the exposed portion turns soluble in an alkali developer, while the unexposed portion is Since it remains hardly soluble in the alkali developer, the exposed portion is removed by alkali development, and a resist pattern is formed.
The component (A) may be a resin component (A1) (hereinafter also referred to as component (A1)) whose solubility in an alkaline developer is increased by the action of an acid. It may be a low molecular compound (A2) (hereinafter sometimes referred to as the component (A2)) whose solubility in a liquid is increased, or a mixture thereof.
Hereinafter, preferred embodiments of the component (A1) and the component (A2) will be described more specifically.

[(A1) component]
Component (A1) is proposed as a base resin for conventional chemically amplified KrF positive resist compositions, ArF positive resist compositions, EB positive resist compositions, EUV positive resist compositions, etc. Among these, it can be appropriately selected depending on the type of exposure light source used when forming the resist pattern.
As the base resin, a resin having a structural unit containing an acid dissociable, dissolution inhibiting group is usually used. Examples of the resin include novolak resins, polyhydroxystyrene resins (for example, (A12) component described later), Examples thereof include acrylic resins (for example, (A11) component described later).
Here, the acid dissociable, dissolution inhibiting group is acid dissociable that can be dissociated by the action of the acid generated from the component (B), and the entire component (A) before the dissociation is hardly soluble in an alkali developer. It is a group having alkali dissolution inhibiting properties. Therefore, in the component (A), when an acid is generated from the component (B) by exposure, the acid dissociable, dissolution inhibiting group is dissociated by the action of the acid, and as a result, the entire component (A) changes to alkali-soluble. .
As the acid dissociable, dissolution inhibiting group, those proposed so far as the acid dissociable, dissolution inhibiting group of the base resin for chemically amplified resist can be used. In general, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group in (meth) acrylic acid or the like; an acetal-type acid dissociable, dissolution inhibiting group such as an alkoxyalkyl group is widely known. . The “(meth) acrylic acid ester” means one or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the α-position.
Here, the “tertiary alkyl ester” is an ester formed by replacing a hydrogen atom of a carboxy group with a chain or cyclic alkyl group, and the carbonyloxy group (—C (O)). A structure in which the tertiary carbon atom of the chain or cyclic alkyl group is bonded to the terminal oxygen atom of -O-). In this tertiary alkyl ester, when an acid acts, a bond is cut between an oxygen atom and a tertiary carbon atom.
The chain or cyclic alkyl group may have a substituent.
Hereinafter, a group that is acid dissociable by constituting a carboxy group and a tertiary alkyl ester is referred to as a “tertiary alkyl ester type acid dissociable, dissolution inhibiting group” for convenience.

Examples of the tertiary alkyl ester type acid dissociable, dissolution inhibiting group include an aliphatic branched acid dissociable, dissolution inhibiting group and an acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group.
Here, “aliphatic branched” means having a branched structure having no aromaticity. The structure of the “aliphatic branched acid dissociable, dissolution inhibiting group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.
Examples of the aliphatic branched acid dissociable, dissolution inhibiting group include a group represented by -C (R ⁷¹ ) (R ⁷² ) (R ⁷³ ). ^Wherein, R 71 ^{to R 73} each independently represents a linear alkyl group of 1 to 5 carbon atoms. The group represented by —C (R ⁷¹ ) (R ⁷² ) (R ⁷³ ) preferably has 4 to 8 carbon atoms, specifically, a tert-butyl group or a 2-methyl-2-butyl group. , 2-methyl-2-pentyl group, 3-methyl-3-pentyl group and the like. A tert-butyl group is particularly preferable.

The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity.
The aliphatic cyclic group may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O). , Etc.
The basic ring structure excluding the substituent of the “aliphatic cyclic group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.
Examples of the aliphatic cyclic group include one or more hydrogens from a monocycloalkane which may or may not be substituted with an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated alkyl group. Examples thereof include a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as bicycloalkane, tricycloalkane, and tetracycloalkane. More specifically, a group obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane or cyclohexane or one or more polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane. And a group in which a hydrogen atom is removed. Further, a part of the carbon atoms constituting the ring of a group obtained by removing one or more hydrogen atoms from these monocycloalkanes or a group obtained by removing one or more hydrogen atoms from polycycloalkanes are etheric oxygen atoms (- O-) may be substituted.
In the present invention, the aliphatic cyclic group is preferably a polycyclic group.

Examples of the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group include:
(I) a group having a tertiary carbon atom on the ring skeleton of a monovalent aliphatic cyclic group;
(Ii) a group having a monovalent aliphatic cyclic group and a branched alkylene having a tertiary carbon atom bonded thereto, and the like.
(I) Specific examples of the group having a tertiary carbon atom on the ring skeleton of the monovalent aliphatic cyclic group are represented by the following general formulas (1-1) to (1-9). Groups and the like.
(Ii) Specific examples of the group having a monovalent aliphatic cyclic group and a branched alkylene group having a tertiary carbon atom bonded thereto include, for example, the following general formulas (2-1) to (2-1) And the group represented by (2-6).

［式中、Ｒ^１４はアルキル基であり、ｇは０〜８の整数である。］

[Wherein, R ¹⁴ represents an alkyl group, and g represents an integer of 0 to 8. ]

［式中、Ｒ^１５およびＲ^１６は、それぞれ独立してアルキル基である。］

[Wherein, R ¹⁵ and R ¹⁶ each independently represents an alkyl group. ]

The alkyl group for R ¹⁴ is preferably a linear or branched alkyl group.
The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and still more preferably 1 or 2. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.
The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group and the like, and isopropyl group is most preferable.
g is preferably an integer of 0 to 3, more preferably an integer of 1 to 3, and still more preferably 1 or 2.
Examples of the alkyl group for R ^{15 to} R ¹⁶ include the same alkyl groups as those for R ¹⁴ .
In the formulas (1-1) to (1-9) and (2-1) to (2-6), a part of the carbon atoms constituting the ring is substituted with an etheric oxygen atom (—O—). May be.
In formulas (1-1) to (1-9) and (2-1) to (2-6), a hydrogen atom bonded to a carbon atom constituting the ring may be substituted with a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, and a fluorinated alkyl group.

The “acetal-type acid dissociable, dissolution inhibiting group” is generally bonded to an oxygen atom by substituting a hydrogen atom at the terminal of an alkali-soluble group such as a carboxy group or a hydroxyl group. When an acid is generated by exposure, the acid acts to break the bond between the acetal acid dissociable, dissolution inhibiting group and the oxygen atom to which the acetal acid dissociable, dissolution inhibiting group is bonded.
Examples of the acetal type acid dissociable, dissolution inhibiting group include a group represented by the following general formula (p1).

［式中、Ｒ^１’，Ｒ^２’はそれぞれ独立して水素原子または炭素数１〜５のアルキル基を表し、ｎは０〜３の整数を表し、Ｙは炭素数１〜５のアルキル基または脂肪族環式基を表す。］

[Wherein, R ¹ ′ and R ² ′ each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, n represents an integer of 0 to 3, and Y represents an alkyl group having 1 to 5 carbon atoms. Or represents an aliphatic cyclic group. ]

In the formula (p1), n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
Examples of the alkyl group having 1 to 5 carbon atoms of R ¹ ′ and R ² ′ include the same alkyl groups as those described above for R. A methyl group or an ethyl group is preferable, and a methyl group is most preferable.
In the present invention, it is preferable that at least one of R ¹ ′ and R ² ′ is a hydrogen atom. That is, the acid dissociable, dissolution inhibiting group (p1) is preferably a group represented by the following general formula (p1-1).

［式中、Ｒ^１’、ｎ、Ｙは上記と同じである。］

[Wherein R ¹ ′, n and Y are the same as described above. ]

Examples of the alkyl group for Y include the same alkyl groups as those described above for R.
The aliphatic cyclic group for Y can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups that have been proposed in a number of conventional ArF resists. For example, the above “aliphatic ring” Examples thereof are the same as those in the formula group.

  Examples of the acetal type acid dissociable, dissolution inhibiting group also include a group represented by the following general formula (p2).

［式中、Ｒ^１７、Ｒ^１８はそれぞれ独立して直鎖状若しくは分岐鎖状のアルキル基または水素原子であり；Ｒ^１９は直鎖状、分岐鎖状若しくは環状のアルキル基である。または、Ｒ^１７およびＲ^１９がそれぞれ独立に直鎖状若しくは分岐鎖状のアルキレン基であって、Ｒ^１７の末端とＲ^１９の末端とが結合して環を形成していてもよい。］

[Wherein, R ¹⁷ and R ¹⁸ each independently represents a linear or branched alkyl group or a hydrogen atom; and R ¹⁹ represents a linear, branched or cyclic alkyl group. Alternatively, R ¹⁷ and R ¹⁹ may be each independently a linear or branched alkylene group, and the end of R ^{17 and} the end of R ¹⁹ may be bonded to form a ring. ]

In R ¹⁷ and R ¹⁸ , the alkyl group preferably has 1 to 15 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group.
In particular, it is preferable that one of R ¹⁷ and R ¹⁸ is a hydrogen atom and the other is a methyl group.
R ¹⁹ is a linear, branched or cyclic alkyl group, preferably having 1 to 15 carbon atoms, and may be any of linear, branched or cyclic.
When R ¹⁹ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group.
When R ¹⁹ is cyclic, it preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, one or more polycycloalkanes such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group. And the like, in which a hydrogen atom is removed. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
In the formula (p2), R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 5 carbon atoms), and the end of R ¹⁹ is The terminal of R ¹⁷ may be bonded.
In this case, a cyclic group is formed by R ¹⁷ , R ¹⁹ , the oxygen atom to which R ¹⁹ is bonded, and the carbon atom to which the oxygen atom and R ¹⁷ are bonded. The cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

  Specific examples of the acetal type acid dissociable, dissolution inhibiting group include groups represented by the following formulas (p3-1) to (p3-12).

［式中、Ｒ^１３は水素原子またはメチル基であり、ｇは前記と同じである。］

[Wherein, R ¹³ represents a hydrogen atom or a methyl group, and g is the same as defined above. ]

More specifically, examples of the structural unit containing an acid dissociable, dissolution inhibiting group include structural units (a1) and (a7) described later.
The component (A1) may contain a constituent unit other than the constituent unit containing an acid dissociable, dissolution inhibiting group. As the other structural unit, any structural unit proposed for use in a base resin for a chemically amplified resist can be used. Examples of the structural unit include structural units (a2) to (a7) described later. ) And the like.

-Structural unit (a1):
The structural unit (a1) is a structural unit derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.
The acid dissociable, dissolution inhibiting group in the structural unit (a1) has an alkali dissolution inhibiting property that makes the entire component (A1) hardly soluble in an alkali developer before dissociation, and an acid generated by exposure from an acid generator. To increase the solubility of the entire component (A1) in the alkaline developer.

Here, the “structural unit derived from an acrylate ester” means a structural unit configured by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid esters” include those in which a hydrogen atom is bonded to the carbon atom at the α-position, and those in which a substituent (atom or group other than a hydrogen atom) is bonded to the carbon atom in the α-position. Include concepts. Examples of the substituent include an alkyl group and a halogenated alkyl group. Note that the α-position (α-position carbon atom) of a structural unit derived from an acrylate ester means a carbon atom to which a carbonyl group is bonded, unless otherwise specified.
The alkyl group as a substituent bonded to the α-position carbon atom is preferably an alkyl group having 1 to 5 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, Examples thereof include linear or branched alkyl groups such as isobutyl group, tert-butyl group, pentyl group, isopentyl group, and neopentyl group.
Specific examples of the halogenated alkyl group include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
In a structural unit derived from an acrylate ester, the α-position of the acrylate ester is bonded to a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. It is more preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, it is preferably a hydrogen atom or a methyl group. Most preferred.

Examples of the acid dissociable, dissolution inhibiting group in the structural unit (a1) include the same groups as those described above.
As the structural unit (a1), one or more selected from the group consisting of structural units represented by the following general formula (a1-0-1) and structural units represented by the following general formula (a1-0-2): Is preferably used.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基またはハロゲン化アルキル基を示し；Ｘ^１およびＸ^２はそれぞれ独立に酸解離性溶解抑制基を示し；Ｙ^２は２価の連結基を示す。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group; X ¹ and X ² each independently represent an acid dissociable, dissolution inhibiting group; Y ² represents a divalent linkage. Indicates a group. ]

In general formula (a1-0-1), the alkyl group having 1 to 5 carbon atoms or the halogenated alkyl group represented by R is an alkyl group having 1 to 5 carbon atoms which may be bonded to the α-position of the acrylate ester. The thing similar to what was mentioned as a halogenated alkyl group is mentioned.
X ¹ is not particularly limited as long as it is an acid dissociable, dissolution inhibiting group, and examples thereof include the above-described tertiary alkyl ester type acid dissociable, dissolution inhibiting group and acetal type acid dissociable, dissolution inhibiting group. And tertiary alkyl ester type acid dissociable, dissolution inhibiting groups are preferred.
In general formula (a1-0-2), R is the same as defined above.
X ² is the same as X ¹ in formula (a1-0-1).

Preferred examples of Y ² include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like.
In the “divalent hydrocarbon group optionally having substituent (s)” in Y ^2, the hydrocarbon group has “substituent” means that part or all of the hydrogen atoms in the hydrocarbon group are It means substituted with a group or atom other than a hydrogen atom.
The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity.
The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.
More specifically, examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, still more preferably 1 to 5, and most preferably 1 to 2.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group [—CH ₂ —], an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [ — (CH ₂ ) ₃ —], tetramethylene group [— (CH ₂ ) ₄ —], pentamethylene group [— (CH ₂ ) ₅ —] and the like can be mentioned.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ). _{2 -, - C (CH 3} ) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as - _{CH (CH 3) CH 2 -} , - CH (CH 3) CH (CH 3) -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - C (CH 2 CH _{3) 2} -CH ₂ - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - alkyl trimethylene groups such as; -CH _(CH 3) _{CH 2 CH 2 CH 2 -,} - CH 2 CH (CH 3) CH 2 CH 2 - And the like alkyl alkylene group such as an alkyl tetramethylene group of. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.

Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and the cyclic aliphatic hydrocarbon group described above. Examples thereof include a group bonded to the terminal of the chain aliphatic hydrocarbon group or interposed in the middle of the chain aliphatic hydrocarbon group.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic group, a group in which two hydrogen atoms have been removed from a monocycloalkane having 3 to 6 carbon atoms is preferable, and examples of the monocycloalkane include cyclopentane and cyclohexane.
As the polycyclic group, a group in which two hydrogen atoms are removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specifically, the polycycloalkane includes adamantane, norbornane, isobornane, tricyclodecane, tetra And cyclododecane.
The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O).

Examples of the aromatic hydrocarbon group include aromatics of monovalent aromatic hydrocarbon groups such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. A divalent aromatic hydrocarbon group obtained by removing one hydrogen atom from the nucleus of the aromatic hydrocarbon;
An aromatic hydrocarbon group in which a part of carbon atoms constituting the ring of the divalent aromatic hydrocarbon group is substituted with a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom;
A benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, an 1-naphthylethyl group, an arylalkyl group such as a 2-naphthylethyl group, etc., and a hydrogen atom from the nucleus of the aromatic hydrocarbon Further, an aromatic hydrocarbon group from which one is removed;
The aromatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O).

The hetero atom in the “divalent linking group containing a hetero atom” is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.
Specific examples of the divalent linking group containing a hetero atom include —O—, —C (═O) —, —C (═O) —O—, and a carbonate bond (—O—C (═O) —. O-), -NH-, ^-NR04 ( ^R04 is an alkyl group)-, -NH-C (= O)-, = N- and the like. Moreover, the combination etc. of these "divalent coupling groups containing a hetero atom" and a bivalent hydrocarbon group are mentioned. Examples of the divalent hydrocarbon group include the same hydrocarbon groups that may have a substituent as described above, and a linear or branched aliphatic hydrocarbon group is preferable.

In the present invention, the divalent linking group for Y ² is preferably an alkylene group, a divalent aliphatic cyclic group or a divalent linking group containing a hetero atom. Among these, an alkylene group is particularly preferable.
When Y ² is an alkylene group, the alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms, It is most preferable that it is number 1-3. Specific examples include the same linear alkylene groups and branched alkylene groups as mentioned above.
When Y ² is a divalent aliphatic cyclic group, the aliphatic cyclic group is the same as the cyclic aliphatic hydrocarbon group mentioned in the above “aliphatic hydrocarbon group containing a ring in the structure”. Can be mentioned.
The aliphatic cyclic group is particularly preferably a group in which two or more hydrogen atoms have been removed from cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane or tetracyclododecane.

When Y ² is a divalent linking group containing a hetero atom, preferred examples of the linking group include —O—, —C (═O) —O—, —C (═O) —, —O—C. (═O) —O—, —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group or an acyl group), —S—, —S ( ═O) ₂ —, —S (═O) ₂ —O—, a group represented by the general formula —A—O—B—, a general formula — [A—C (═O) —O] _d —B— The group etc. which are represented by these are mentioned. Here, A and B are each independently a divalent hydrocarbon group which may have a substituent, and d is an integer of 0 to 3.
When Y ² is —NH—, H may be substituted with a substituent such as an alkyl group or an acyl group. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.

In the general formula —A—O—B— or — [A—C (═O) —O] _d —B—, each of A and B independently represents a divalent group that may have a substituent. It is a hydrocarbon group.
Examples of the divalent hydrocarbon group which may have a substituent in A and B are the same as those described above as the “divalent hydrocarbon group which may have a substituent” in R ² . Can be mentioned.
A is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group. .
B is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.
In the group represented by the formula- _[ AC (= O) -O] _d -B-, d is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1. Preferably 1 is most preferred.

  More specifically, examples of the structural unit (a1) include structural units represented by the following general formulas (a1-1) to (a1-4).

［式中、Ｘ’は第３級アルキルエステル型酸解離性溶解抑制基を表し、Ｙは炭素数１〜５のアルキル基、または脂肪族環式基を表し；ｎは０〜３の整数を表し；Ｙ^２は２価の連結基を表し；Ｒは前記と同じであり、Ｒ^１’、Ｒ^２’はそれぞれ独立して水素原子または炭素数１〜５のアルキル基を表す。］

[Wherein, X ′ represents a tertiary alkyl ester-type acid dissociable, dissolution inhibiting group, Y represents an alkyl group having 1 to 5 carbon atoms, or an aliphatic cyclic group; n represents an integer of 0 to 3; Y ² represents a divalent linking group; R is the same as defined above; R ¹ ′ and R ² ′ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ]

Wherein, X 'include the same tertiary alkyl ester-type acid dissociable, dissolution inhibiting groups as those described above for X ^{1.
R 1 ', R 2',} n, as the Y, respectively, ^{R 1} in the general formula listed in the description of "acetal-type acid dissociable, dissolution inhibiting group" described above ^{(p1) ', R 2'} , n, Y The same thing is mentioned.
The Y ^2, the same groups as those described above for ^{Y 2} in the general formula (a1-0-2).
Specific examples of the structural units represented by the general formulas (a1-1) to (a1-4) are shown below.
In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

As the structural unit (a1), one type may be used alone, or two or more types may be used in combination.
Among the above, the structural unit represented by the general formula (a1-1) or (a1-3) is preferable, and specifically, (a1-1-1) to (a1-1-4), (a1-1) It is more preferable to use at least one selected from the group consisting of -20) to (a1-1-23) and (a1-3-25) to (a1-3-28).
Furthermore, as the structural unit (a1), those represented by the following general formula (a1-1-01) that include structural units of the formula (a1-1-1) to the formula (a1-1-3), In the following general formula (a1-1-02) including the structural units of formulas (a1-1-16) to (a1-1-17) and formulas (a1-1-20) to (a1-1-23) Represented by the following general formula (a1-3-01) including structural units of the formulas (a1-3-25) to (a1-3-26), or the formula (a1-3- What is represented by the following general formula (a1-3-02) including the structural units of 27) to (a1-3-28) is also preferable. In addition, the following general formula (a1-3) including the structural units represented by the formulas (a1-3-13) to (a1-3-24) and (a1-3-29) to (a1-3-32). Those represented by 3-03) are also preferred.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基またはハロゲン化アルキル基を示し、Ｒ^１１は炭素数１〜５のアルキル基を示す。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group, and R ¹¹ represents an alkyl group having 1 to 5 carbon atoms. ]

［式中、Ｒは水素原子、炭素数１〜５のアルキル基またはハロゲン化アルキル基を示し、Ｒ^１２は炭素数１〜５のアルキル基を示す。ｈは１〜６の整数を表す。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group, and R ¹² represents an alkyl group having 1 to 5 carbon atoms. h represents an integer of 1 to 6. ]

In general formula (a1-1-01), R is the same as defined above. The alkyl group for R ^{11 is the same as} the alkyl group for R, and is preferably a methyl group or an ethyl group.
In general formula (a1-1-02), R is the same as defined above. The alkyl group for R ^{12 is the same as} the alkyl group for R, preferably a methyl group or an ethyl group, and most preferably an ethyl group. h is preferably 1 or 2, and most preferably 2.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基またはハロゲン化アルキル基を示し；Ｒ^１４は炭素数１〜５のアルキル基であり、Ｒ^１３は水素原子またはメチル基であり、ａは１〜１０の整数である。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group; R ¹⁴ represents an alkyl group having 1 to 5 carbon atoms; R ¹³ represents a hydrogen atom or a methyl group; a is an integer of 1-10. ]

［式中、Ｒは水素原子、炭素数１〜５のアルキル基またはハロゲン化アルキル基を示し；Ｒ^１４はアルキル基であり、Ｒ^１３は水素原子またはメチル基であり、ａは１〜１０の整数であり、ｎ’は１〜６の整数である。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group; R ¹⁴ represents an alkyl group, R ¹³ represents a hydrogen atom or a methyl group, and a represents 1-10. It is an integer and n ′ is an integer of 1-6. ]

In the general formula (a1-3-01) or (a1-3-02), R is the same as described above.
R ¹³ is preferably a hydrogen atom.
The alkyl group for R ^{14 is the same as} the alkyl group for R, and is preferably a methyl group or an ethyl group.
a is preferably an integer of 1 to 8, more preferably an integer of 2 to 5, and most preferably 2.

［式中、ＲおよびＸ^２はそれぞれ前記と同じであり、Ｙ^２’およびＹ^２”はそれぞれ独立して２価の連結基であり、ｎ”は０〜３の整数である。］

[Wherein, R and X ² are the same as defined above, Y ² ′ and Y ² ″ are each independently a divalent linking group, and n ″ is an integer of 0 to 3. ]

In formula (a1-3-03), examples of the divalent linking group for Y ² ′ and Y ² ″ include the same groups as those described above for Y ² .
Y ² ′ is preferably a divalent hydrocarbon group which may have a substituent, more preferably a linear aliphatic hydrocarbon group, and even more preferably a linear alkylene group. Among these, a linear alkylene group having 1 to 5 carbon atoms is preferable, and a methylene group or an ethylene group is most preferable.
Y ² ″ is preferably a divalent hydrocarbon group which may have a substituent, more preferably a linear aliphatic hydrocarbon group, and still more preferably a linear alkylene group. A linear alkylene group of 1 to 5 is preferable, and a methylene group and an ethylene group are most preferable.
Examples of the acid dissociable, dissolution inhibiting group for X ² are the same as those described above.
X ² in the formula (a1-3-03) is preferably a tertiary alkyl ester type acid dissociable, dissolution inhibiting group, and the above-mentioned (i) the third group on the ring skeleton of the monovalent aliphatic cyclic group. A group having a secondary carbon atom is more preferable, and a group in which the aliphatic cyclic group is a polycyclic group (aliphatic polycyclic group) is particularly preferable. Among these, a group represented by the general formula (1-1) is preferable.
n ″ is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.

Structural unit (a2):
The structural unit (a2) is a structural unit derived from an acrylate ester containing a lactone-containing cyclic group.
Here, the lactone-containing cyclic group refers to a cyclic group containing one ring (lactone ring) containing an —O—C (O) — structure. The lactone ring is counted as the first ring, and when it is only the lactone ring, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure.
When the component (A1) is used for forming a resist film, the lactone cyclic group of the structural unit (a2) increases the adhesion of the resist film to the substrate or has an affinity for a developer containing water. It is effective in raising.
As the structural unit (a2), any unit can be used without any particular limitation.
Specifically, the lactone-containing monocyclic group is a group obtained by removing one hydrogen atom from a 4- to 6-membered ring lactone, such as a group obtained by removing one hydrogen atom from β-propionolactone, or γ-butyrolactone. Examples thereof include a group in which one hydrogen atom has been removed, and a group in which one hydrogen atom has been removed from δ-valerolactone. Examples of the lactone-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring.
More specifically, examples of the structural unit (a2) include structural units represented by general formulas (a2-1) to (a2-5) shown below.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり；Ｒ’はそれぞれ独立に水素原子、炭素数１〜５のアルキル基、炭素数１〜５のアルコキシ基または−ＣＯＯＲ”であり、Ｒ”は水素原子またはアルキル基であり；Ｒ^２９は単結合または２価の連結基であり、ｓ”は０〜２の整数であり；Ａ”は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子であり；ｍは０または１である。］

[Wherein, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ′ is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, carbon An alkoxy group of 1 to 5 or —COOR ″, R ″ is a hydrogen atom or an alkyl group; R ²⁹ is a single bond or a divalent linking group, and s ″ is an integer of 0 to 2; A ″ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom; m is 0 or 1. ]

R in the general formulas (a2-1) to (a2-5) is the same as R in the structural unit (a1).
Examples of the alkyl group having 1 to 5 carbon atoms of R ′ include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group.
Examples of the alkoxy group having 1 to 5 carbon atoms of R ′ include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group.
R ′ is preferably a hydrogen atom in view of industrial availability.
The alkyl group in R ″ may be linear, branched or cyclic.
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms.
When R ″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a fluorine atom Or a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group Specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Etc.
Examples of A ″ include the same as A ′ in the general formula (3-1). A ″ represents an alkylene group having 1 to 5 carbon atoms, an oxygen atom (—O—) or a sulfur atom (— S-) is preferable, and an alkylene group having 1 to 5 carbon atoms or -O- is more preferable. The alkylene group having 1 to 5 carbon atoms is more preferably a methylene group or dimethylmethylene group, and most preferably a methylene group.

R ²⁹ is a single bond or a divalent linking group. As a bivalent coupling group, the thing similar to the bivalent coupling group demonstrated by R < ² > in the said general formula (a0-1) is mentioned. Among these, an alkylene group, an ester bond (—C (═O) —O—), or a combination thereof is preferable. The alkylene group as the divalent linking group for R ²⁹ is more preferably a linear or branched alkylene group. Specifically, the same as the linear alkylene group and the branched alkylene group mentioned as the aliphatic hydrocarbon group for R ² can be used.
As R ²⁹ , in particular, a single bond or —R ²⁹ ′ —C (═O) —O— [wherein R ²⁹ ′ is a linear or branched alkylene group. ] Is preferable.
The linear or branched alkylene group for R ²⁹ ′ preferably has 1 to 10 carbon atoms, more preferably 1 to 8, still more preferably 1 to 5, particularly preferably 1 to 3. ~ 2 is most preferred.
As the linear alkylene group for R ²⁹ ′, a methylene group or an ethylene group is preferable, and a methylene group is particularly preferable. The branched alkylene group for R ²⁹ ′ is preferably an alkylmethylene group or an alkylethylene group, and —CH (CH ₃ ) —, —C (CH ₃ ) ₂ — or —C (CH ₃ ) ₂ CH ₂ — Is particularly preferred.
In formula (a2-1), s ″ is preferably 1 to 2.
Specific examples of the structural units represented by the general formulas (a2-1) to (a2-5) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

In the component (A1), as the structural unit (a2), one type may be used alone, or two or more types may be used in combination.
In the present invention, the component (A1) is at least one selected from the group consisting of structural units represented by any one of the general formulas (a2-1) to (a2-5) as the structural unit (a2). It is preferable that at least one selected from the group consisting of structural units represented by any one of the general formulas (a2-1) to (a2-3) is more preferable. It is particularly preferable to have at least one selected from the group consisting of structural units represented by 1) or (a2-2).

-Structural unit (a3):
The structural unit (a3) is a structural unit derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.
When the component (A1) has the structural unit (a3), the hydrophilicity of the component (A1) is increased, the affinity with the developer is increased, the alkali solubility in the exposed area is improved, and the resolution is improved. Contributes to improvement.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom. A hydroxyl group is particularly preferable.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a polycyclic aliphatic hydrocarbon group (polycyclic group). It is done. As the polycyclic group, for example, a resin for a resist composition for ArF excimer laser can be appropriately selected from among many proposed ones. The polycyclic group preferably has 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom Is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, there are groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane. Industrially preferable.

  The structural unit (a3) is derived from a hydroxyethyl ester of acrylic acid when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms. The structural unit is preferred. When the hydrocarbon group is a polycyclic group, it is represented by the structural unit represented by the following formula (a3-1), the structural unit represented by (a3-2), or (a3-3). A structural unit is mentioned as a preferable thing.

［式中、Ｒは前記に同じであり、ｊは１〜３の整数であり、ｋは１〜３の整数であり、ｔ’は１〜３の整数であり、ｌは１〜５の整数であり、ｓは１〜３の整数である。］

[Wherein, R is as defined above, j is an integer of 1 to 3, k is an integer of 1 to 3, t ′ is an integer of 1 to 3, and l is an integer of 1 to 5] And s is an integer of 1 to 3. ]

In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.
j is preferably 1, and a hydroxyl group bonded to the 3rd position of the adamantyl group is particularly preferred.
In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.
In formula (a3-3), t ′ is preferably 1. l is preferably 1. s is preferably 1. These preferably have a 2-norbornyl group or a 3-norbornyl group bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.
As the structural unit (a3), one type may be used alone, or two or more types may be used in combination.

-Structural unit (a4):
The structural unit (a4) is a structural unit derived from another acrylate ester not classified into the above-described structural units (a1) to (a3).
As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing a non-acid-dissociable aliphatic polycyclic group is preferable. Examples of the polycyclic group include those exemplified in the case of the structural unit (a1), and for ArF excimer laser and KrF excimer laser (preferably for ArF excimer laser). A number of hitherto known materials can be used as the resin component of the resist composition.
In particular, at least one selected from a tricyclodecanyl group, an adamantyl group, a tetracyclododecanyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.
Specific examples of the structural unit (a4) include those represented by the following general formulas (a4-1) to (a4-5).

［式中、Ｒは前記と同じである。］

[Wherein, R is the same as defined above. ]

-Structural unit (a5):
The structural unit (a5) is a structural unit derived from hydroxystyrene.
Here, “structural unit derived from hydroxystyrene” means a structural unit formed by cleavage of an ethylenic double bond of hydroxystyrene.
“Hydroxystyrene” refers to hydroxystyrene in a narrow sense (= a compound in which at least one hydroxyl group is bonded to the benzene ring of vinylbenzene; hereinafter, sometimes referred to as unsubstituted hydroxystyrene), and α of the unsubstituted hydroxystyrene. It is a concept that includes a hydrogen atom bonded to a carbon atom at the position substituted with a substituent (α-substituted hydroxystyrene) and derivatives thereof. That is, it is simply referred to as “hydroxystyrene”, and there is no particular limitation. The “hydroxystyrene” may be any of unsubstituted hydroxystyrene, α-substituted hydroxystyrene, and derivatives thereof. The α-position carbon atom of hydroxystyrene means a carbon atom to which a benzene ring is bonded unless otherwise specified.
Examples of the substituent that may be bonded to the α-position carbon atom in the α-substituted hydroxystyrene include an alkyl group having 1 to 5 carbon atoms, and an alkyl group having 1 to 5 carbon atoms is particularly preferable. The alkyl group is preferably a linear or branched alkyl group, and specifically includes a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, and pentyl. Group, isopentyl group, neopentyl group and the like.
Examples of the derivative include compounds in which a substituent is bonded to the benzene ring of unsubstituted hydroxystyrene or α-substituted hydroxystyrene.
Preferred examples of the structural unit (a5) include structural units represented by general formula (a5-1) shown below.

［式（ａ５−１）中、Ｒ’は水素原子または炭素数１〜５のアルキル基であり；Ｒ^６はハロゲン原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり；ｐは１〜３の整数であり；ｑは０〜４の整数であり、ｐ＋ｑは１〜５である。］

[In formula (a5-1), R ′ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; R ⁶ is a halogen atom, an alkyl group having 1 to 5 carbon atoms or an alkyl halide having 1 to 5 carbon atoms; P is an integer of 1 to 3; q is an integer of 0 to 4, and p + q is 1 to 5. ]

In formula (a5-1), R ′ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.
Examples of the alkyl group for R ′ include the same groups as those described above as the alkyl group that may be bonded to the α-position carbon atom of the α-substituted hydroxystyrene in the description of hydroxystyrene.
R ′ is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, particularly preferably a hydrogen atom or a methyl group.
p is an integer of 1 to 3, q is an integer of 0 to 4, and p + q is 1 to 5. However, p + q is 1-5.
p is most preferably 1.
q is preferably an integer of 0 to 2, more preferably 0 or 1, and industrially particularly preferably 0.

In formula (a5-1), the bonding position of the hydroxyl group in the phenyl group is not particularly limited. When p is 1, any of the o-position, m-position and p-position may be used, and the p-position is preferred because it is readily available and inexpensive. When p is 2 or 3, any bonding position can be combined.
Moreover, the bonding position of R ^{2 in} the phenyl group is not particularly limited. When q is 1, any of the o-position, m-position and p-position may be used. When q is an integer greater than or equal to 2, arbitrary bond positions can be combined.
When q is an integer of 2 or more, the plurality of R ² may be the same or different.

R ⁶ is a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.
Examples of the halogen atom for R ⁶ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
As the alkyl group for R ^6, the same alkyl groups as those for R ¹ can be used.
Examples of the halogenated alkyl group for R ^6, part or all of the hydrogen atoms in the alkyl group of the R ⁶ are mentioned group substituted by a halogen atom, Examples of the halogen atom, mentioned as the halogen atom of R ⁶ The thing similar to a thing is mentioned. The halogenated alkyl group for R ⁶ is preferably a fluorinated alkyl group.

  As the structural unit (a5), one type of structural unit may be used alone, or two or more types of structural units may be used in combination.

-Structural unit (a6):
The structural unit (a6) is a structural unit derived from styrene.
Here, in the present specification, “structural unit derived from styrene” means a structural unit formed by cleavage of an ethylenic double bond of styrene.
“Styrene” means styrene in a narrow sense (= vinylbenzene; hereinafter sometimes referred to as unsubstituted styrene), and a hydrogen atom bonded to the α-position carbon atom of the unsubstituted styrene is substituted with a substituent. The concept includes products (α-substituted styrene) and derivatives thereof. That is, it is simply referred to as “styrene”, and there is no particular limitation. The “styrene” may be any of unsubstituted styrene, α-substituted styrene, and derivatives thereof. The α-position carbon atom of styrene means a carbon atom to which a benzene ring is bonded unless otherwise specified.
Examples of the substituent that may be bonded to the α-position carbon atom in the α-substituted styrene include an alkyl group having 1 to 5 carbon atoms, and an alkyl group having 1 to 5 carbon atoms is particularly preferable. The alkyl group is preferably a linear or branched alkyl group, and specifically includes a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, and pentyl. Group, isopentyl group, neopentyl group and the like.
Examples of the derivative include those in which a substituent is bonded to the benzene ring of unsubstituted styrene or α-substituted styrene.
As the structural unit (a6), for example, a structural unit represented by general formula (a6-1) shown below can be exemplified.

［式（ａ６−１）中、Ｒ’は前記と同じであり；Ｒ^７はハロゲン原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり；ｒは０〜５の整数である。］
［式中、Ｒ^１は前記と同じであり、Ｒ^３はハロゲン原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり、ｒは０〜５の整数である。］

[In the formula (a6-1), R ′ is the same as above; R ⁷ is a halogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; It is an integer of 5. ]
[Wherein, R ¹ is the same as above, R ³ is a halogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and r is an integer of 0 to 5] . ]

In formula (a6-1), examples of R ′ and R ⁷ are the same as R ′ and R ^{6 in} formula (a5-1).
r is preferably an integer of 0 to 3, more preferably 0 or 1, and most preferably 0 industrially.
When r is 1, the substitution position of R ⁷ may be any of the o-position, m-position and p-position of the phenyl group.
When r is 2 or 3, any substitution position can be combined. The plurality of R ⁷ may be the same or different.
As the structural unit (a6), one type may be used alone, or two or more types may be used in combination.

-Structural unit (a7):
The structural unit (a7) is a structural unit derived from hydroxystyrene, and at least one of the hydrogen atoms of the hydroxyl group contained in the structural unit includes an acid dissociable, dissolution inhibiting group or an acid dissociable, dissolution inhibiting group. A structural unit substituted with an organic group.
As the structural unit (a7), it is preferable that the hydrogen atom of the hydroxyl group in the general formula (a5-1) is substituted with an acid dissociable, dissolution inhibiting group or an organic group containing an acid dissociable, dissolution inhibiting group. Is mentioned.
The acid dissociable, dissolution inhibiting group in the structural unit (a7) is not particularly limited, and may be appropriately selected from many proposed resins for resist compositions such as for KrF excimer laser and ArF excimer laser. Examples thereof include those similar to those exemplified in the structural unit (a1).
As preferred acid dissociable, dissolution inhibiting groups, specifically, tertiary alkyl groups exemplified below as acid dissociable, dissolution inhibiting groups (7-1) and the following acid dissociable, dissolution inhibiting group-containing groups (7-3) A containing group.
The organic group having an acid dissociable, dissolution inhibiting group is not particularly limited. For example, a resin for resist compositions such as for KrF excimer laser and ArF excimer laser is appropriately selected and used. be able to. Specific examples include organic groups having the acid dissociable, dissolution inhibiting groups listed above. Examples include the following acid dissociable, dissolution inhibiting groups as organic groups having an acid dissociable, dissolution inhibiting group (7-1). An organic group (7-2) having a tertiary alkyl group-containing group exemplified by the following acid dissociable, dissolution inhibiting group-containing group (7-3) (for example, a tertiary alkyl group, a tertiary alkyloxycarbonyl group, A tertiary alkyloxycarbonylalkyl group, etc.).

Acid dissociable, dissolution inhibiting group (7-1):
Examples of the acid dissociable, dissolution inhibiting group (7-1) include a group represented by the following general formula (7-1a) and a group represented by the following general formula (7-1b).

［式（７−１ａ）中、Ｒ^２７は直鎖状又は分岐鎖状のアルキレン基を表し；Ｘ^０は脂肪族環式基、芳香族環式炭化水素基又は炭素数１〜５のアルキル基を表す。式（７−１ｂ）中、Ｘ^０は前記式（７−１ａ）におけるＸ^０と同じであり；Ｒ^４は水素原子若しくは炭素数１〜５のアルキル基を表し、又は、Ｘ^０およびＲ^４がそれぞれ独立に炭素数１〜５のアルキレン基であって、Ｘ^０の末端とＲ^４の末端とが結合していてもよく；Ｒ^５は水素原子又は炭素数１〜５のアルキル基を表す。］

[In the formula (7-1a), R ²⁷ represents a linear or branched alkylene group; X ⁰ is an aliphatic cyclic group, an aromatic cyclic hydrocarbon group or an alkyl group having 1 to 5 carbon atoms. Represents. In Formula (7-1b), X ⁰ is the same as X ⁰ in Formula (7-1a); R ⁴ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, or X ⁰ and R ⁴ Are each independently an alkylene group having 1 to 5 carbon atoms, and the end of X ^{0 and} the end of R ⁴ may be bonded; R ⁵ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. . ]

In the general formula (7-1a), R ²⁷ represents a linear or branched alkylene group.
The alkylene group preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms, and still more preferably 1 to 2 carbon atoms.
In the formulas (7-1a) and (7-1b), X ⁰ each independently represents an aliphatic cyclic group, an aromatic cyclic hydrocarbon group, or an alkyl group having 1 to 5 carbon atoms.
Here, the “aliphatic cyclic group” in the present specification and claims means a monocyclic group or a polycyclic group having no aromaticity, and is either saturated or unsaturated. Usually, it is usually preferable to be saturated.
The aliphatic cyclic group for X ⁰ is a monovalent aliphatic cyclic group. The aliphatic cyclic group can be appropriately selected from, for example, those proposed in a number of conventional ArF resists. Specific examples of the aliphatic cyclic group include an aliphatic monocyclic group having 5 to 7 carbon atoms and an aliphatic polycyclic group having 10 to 16 carbon atoms.
Examples of the aliphatic monocyclic group having 5 to 7 carbon atoms include groups in which one hydrogen atom has been removed from a monocycloalkane. Specifically, one hydrogen atom has been removed from cyclopentane, cyclohexane and the like. Group.
Examples of the aliphatic polycyclic group having 10 to 16 carbon atoms include groups in which one hydrogen atom has been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. Specific examples include groups in which one hydrogen atom has been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these, an adamantyl group, a norbornyl group, and a tetracyclododecanyl group are industrially preferable, and an adamantyl group is particularly preferable.
Examples of the aromatic cyclic hydrocarbon group for X ⁰ include aromatic polycyclic groups having 10 to 16 carbon atoms. Specific examples include groups in which one hydrogen atom has been removed from naphthalene, anthracene, phenanthrene, pyrene, and the like. Specific examples include 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 1-pyrenyl group, and the like. A naphthyl group is particularly preferred industrially.
Examples of the alkyl group for X ⁰ include the same alkyl groups as R ′ in the general formula (a5-1), more preferably a methyl group or an ethyl group, and most preferably an ethyl group.

In the formula (7-1b), examples of the alkyl group for R ⁴ include the same alkyl groups as R ′ in the general formula (a5-1). Industrially, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
R ⁵ represents an alkyl group or a hydrogen atom. As the alkyl group for R ^5, the same alkyl groups as those for R ⁴ can be used. R ⁵ is preferably industrially a hydrogen atom.
In particular, it is preferable that either one of R ⁴ and R ⁵ is a hydrogen atom and the other is a methyl group.
In the general formula (7-1b), X ⁰ and R ⁴ are each independently an alkylene group having 1 to 5 carbon atoms, and the end of X ^{0 and} the end of R ⁴ are bonded to each other. Also good. In this case, in the general formula (7-1b), a cyclic group is formed by R ⁴ , X ⁰ , the oxygen atom to which X ⁰ is bonded, and the carbon atom to which the oxygen atom and R ⁴ are bonded. ing. The cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

As the acid dissociable, dissolution inhibiting group (7-1), R ⁵ is a hydrogen atom and R ⁴ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms because of excellent resist pattern shape and the like. Is preferred.
Specific examples of the acid dissociable, dissolution inhibiting group (7-1) include, for example, a group in which X ⁰ is an alkyl group, that is, a 1-alkoxyalkyl group such as a 1-methoxyethyl group, a 1-ethoxyethyl group, 1- Examples include iso-propoxyethyl group, 1-n-butoxyethyl group, 1-tert-butoxyethyl group, methoxymethyl group, ethoxymethyl group, iso-propoxymethyl group, n-butoxymethyl group, tert-butoxymethyl group, etc. It is done.
In addition, examples of the group in which X ⁰ is an aliphatic cyclic group include a 1-cyclohexyloxyethyl group, a 1- (2-adamantyl) oxymethyl group, and 1- (represented by the following formula (7-1-1). 1-adamantyl) oxyethyl group and the like.
Examples of the group in which X ⁰ is an aromatic cyclic hydrocarbon group include a 1- (2-naphthyl) oxyethyl group represented by the following formula (7-1-2).
Among these, a 1-ethoxyethyl group is particularly preferable.

Organic group having acid dissociable, dissolution inhibiting group (7-2):
Examples of the organic group (7-2) having an acid dissociable, dissolution inhibiting group include a group represented by the following general formula (7-2). In the organic group (7-2) having such a structure, when an acid is generated from the component (B1) by exposure, the acid causes an oxygen atom bonded to Y and a carbon atom to which R ⁴ and R ⁵ are bonded. broken bond ^{between, -C (R 4) (R} 5) -OX 0 dissociates.

［式（７−２）中、Ｘ^０は脂肪族環式基、芳香族環式炭化水素基または炭素数１〜５のアルキル基を表し；Ｒ^４は水素原子若しくはアルキル基を表し、又は、Ｘ^０およびＲ^４がそれぞれ独立に炭素数１〜５のアルキレン基であって、Ｘ^０の末端とＲ^４の末端とが結合していてもよく；Ｒ^５はアルキル基または水素原子を表し；Ｙは２価の脂肪族環式基を表す。］

[In Formula (7-2), X ⁰ represents an aliphatic cyclic group, an aromatic cyclic hydrocarbon group, or an alkyl group having 1 to 5 carbon atoms; R ⁴ represents a hydrogen atom or an alkyl group, or X ⁰ and R ⁴ are each independently an alkylene group having 1 to 5 carbon atoms, and the end of X ^{0 and} the end of R ⁴ may be bonded; R ⁵ represents an alkyl group or a hydrogen atom; Y represents a divalent aliphatic cyclic group. ]

In the general formula ^(7-2), as the X ^{0, R 4,} R ^5, respectively the same as ^{X 0, R 4,} R ⁵ in the general formula (7-1b).
Examples of the divalent aliphatic cyclic group for Y, include further groups in which one hydrogen atom has been removed from an aliphatic cyclic group for the X ^0.

Acid-dissociable, dissolution inhibiting group-containing group (7-3)
The acid dissociable, dissolution inhibiting group-containing group (7-3) is composed of the above acid dissociable, dissolution inhibiting group (7-1) and the organic group (7-2) having an acid dissociable, dissolution inhibiting group (hereinafter collectively referred to as these). It is an acid dissociable, dissolution inhibiting group-containing group that is not classified as “acid dissociable, dissolution inhibiting group, etc. (7-1) to (7-2)”.
As the acid dissociable, dissolution inhibiting group-containing group (7-3), among the conventionally known acid dissociable, dissolution inhibiting group-containing groups, the above acid dissociable, dissolution inhibiting groups, etc. (7-1) to (7-2) Any acid dissociable, dissolution inhibiting group-containing group that is not classified can be used.
Specific examples of the acid dissociable, dissolution inhibiting group-containing group (7-3) include a tertiary alkyl group-containing group.
Here, in this specification, the “tertiary alkyl group” refers to an alkyl group having a tertiary carbon atom. As described above, the “alkyl group” represents a monovalent saturated hydrocarbon group, and includes a chain (straight chain or branched chain) alkyl group and an alkyl group having a cyclic structure.
The “tertiary alkyl group-containing group” refers to a group containing a tertiary alkyl group in its structure.
The tertiary alkyl group-containing group may be composed only of a tertiary alkyl group, or may be composed of a tertiary alkyl group and another atom or group other than the tertiary alkyl group. .
Examples of the aforementioned “other atom or group other than the tertiary alkyl group” constituting the tertiary alkyl group-containing group together with the tertiary alkyl group include a carbonyloxy group, a carbonyl group, an alkylene group, and an oxygen atom. .

Examples of the tertiary alkyl group-containing group include a tertiary alkyl group-containing group having no cyclic structure and a tertiary alkyl group-containing group having a cyclic structure.
A tertiary alkyl group-containing group having no cyclic structure is a group containing a branched tertiary alkyl group as the tertiary alkyl group and having no cyclic structure in the structure.
Examples of the branched tertiary alkyl group include a group represented by the following general formula (7-3a).

In formula (7-3a), R ^{21 to} R ²³ are each independently a linear or branched alkyl group. 1-5 are preferable and, as for carbon number of this alkyl group, 1-3 are more preferable.
Specific examples of the alkyl group having 1 to 5 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, and neopentyl group. Can be mentioned.
Moreover, as the general type total number of carbon atoms of the group represented by (7-3a) is 4 to 7, it is preferable to combine the above-described alkyl group ^R 21 ^{to R 23,} the total number of carbon atoms is 4 to 6 It is more preferable to combine the alkyl groups so that the total number of carbon atoms is 4 to 5, and it is most preferable to combine the alkyl groups. Specific examples of the group represented by the general formula (7-3a) include a tert-butyl group and a tert-pentyl group, and a tert-butyl group is more preferable.

Examples of the tertiary alkyl group-containing group that does not have a cyclic structure include the above-described branched tertiary alkyl group; the above-described branched tertiary alkyl group is a linear or branched alkylene group A tertiary alkyl group-containing chain alkyl group bonded to the above; a tertiary alkyloxycarbonyl group having the branched tertiary alkyl group described above as the tertiary alkyl group; And tertiary alkyloxycarbonylalkyl groups having a branched tertiary alkyl group.
The alkylene group in the tertiary alkyl group-containing chain alkyl group is preferably an alkylene group having 1 to 5 carbon atoms, more preferably an alkylene group having 1 to 4 carbon atoms, and still more preferably an alkylene group having 1 to 2 carbon atoms. .
As the chain-like tertiary alkyloxycarbonyl group, for example, a group represented by general formula (7-3b) shown below can be mentioned. ^R 21 ^{to R} in the formula (7-3b) ²³ are respectively similar to the formula (7-3a) in ^R 21 ^{to R 23.} The chain-like tertiary alkyloxycarbonyl group is preferably a tert-butyloxycarbonyl group (t-boc) or a tert-pentyloxycarbonyl group.
As the chain-like tertiary alkyloxycarbonylalkyl group, for example, a group represented by general formula (7-3c) shown below can be mentioned. ^R 21 ^{to R} in the formula (7-3c) ²³ are respectively similar to the formula (7-3a) in ^R 21 ^{to R 23.} f is an integer of 1 to 3, and 1 or 2 is preferable. As the chain-like tertiary alkyloxycarbonylalkyl group, a tert-butyloxycarbonylmethyl group, a tert-pentyloxycarbonylmethyl group, or a tert-butyloxycarbonylethyl group is preferable.

  Of these, the tertiary alkyl group-containing group having no cyclic structure is preferably a tertiary alkyloxycarbonyl group or a tertiary alkyloxycarbonylalkyl group, more preferably a tertiary alkyloxycarbonyl group. And tert-butyloxycarbonyl group (t-boc) is particularly preferable.

The tertiary alkyl group-containing group having a cyclic structure is a group having a tertiary carbon atom and a cyclic structure in the structure.
In the tertiary alkyl group-containing group having a cyclic structure, the cyclic structure preferably has 4 to 12 carbon atoms, more preferably 5 to 10 carbon atoms, and more preferably 6 to 10 carbon atoms constituting the ring. Most preferred. Examples of the cyclic structure include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane. Preferable examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

Examples of the tertiary alkyl group-containing group having a cyclic structure include a group having the following group (1) or (2) as a tertiary alkyl group.
(1) A group in which a linear or branched alkyl group is bonded to a carbon atom constituting a ring of a cyclic alkyl group (cycloalkyl group), and the carbon atom is a tertiary carbon atom.
(2) A group in which an alkylene group having a tertiary carbon atom (branched alkylene group) is bonded to the carbon atom constituting the ring of the cycloalkyl group.

The linear or branched alkyl group in the group (1) preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. .
Specific examples of the group (1) include 2-methyl-2-adamantyl group, 2-ethyl-2-adamantyl group, 1-methyl-1-cycloalkyl group, 1-ethyl-1-cycloalkyl group and the like. More specifically, 1-methylcyclopentyl group, 1-ethylcyclopentyl group, 1-methylcyclohexyl group, 1-ethylcyclohexyl group, 2-methyl-2-adamantyl group, 2-ethyl-2-adamantyl group Etc.

In the group (2), the cycloalkyl group to which the branched alkylene group is bonded may have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.
Specific examples of the group (2) include groups represented by the following general formula (IV).

In the formula (IV), R ²⁴ is a cycloalkyl group which may or may not have a substituent. Examples of the substituent that the cycloalkyl group may have include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (═O).
R ²⁵ and R ²⁶ are each independently a linear or branched alkyl group, and the alkyl group is the same as the alkyl group of R ^{21 to} R ²³ in the formula (7-3a). Can be mentioned.

  In the acid dissociable, dissolution inhibiting group-containing group (7-3), as the tertiary alkyl group-containing group, from the viewpoint of excellent resist pattern shape or lithography properties (depth of focus (DOF), etc.), the general formula (7 A chain-like tertiary alkyloxycarbonyl group represented by -3b) is more preferable, and a tert-butyloxycarbonyl group (t-boc) is most preferable.

The component (A1) may include a structural unit (a8) that does not fall under any of the structural units (a1) to (a7).
The structural unit (a8) is not particularly limited as long as it is another structural unit that is not classified into the structural units (a1) to (a7) described above. For ArF excimer laser, for KrF excimer laser (preferably ArF A number of hitherto known materials can be used for resist resins such as for excimer lasers.

As the component (A1) used in the present invention, the following resins (A11) and resins (A12) are preferable. However, the present invention is not limited to these.
Resin (A11): a structural unit (a5) derived from hydroxystyrene, a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group, and / or a structural unit derived from hydroxystyrene A resin having a structural unit (a7) in which at least one of hydrogen atoms of a hydroxyl group contained in the structural unit is substituted with an acid dissociable, dissolution inhibiting group or an organic group containing an acid dissociable, dissolution inhibiting group.
Resin (A12): An acrylic resin having a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.
The resin (A11) is suitable for electron beams and EUV.
Resin (A12) is suitable for ArF excimer laser.

"Resin (A11)"
In the resin (A11), as the structural unit (a5), one type of structural unit may be used, or two or more types may be used in combination.
The proportion of the structural unit (a5) in the resin (A11) is preferably 50 to 90 mol%, and preferably 55 to 85 mol%, based on the total of all structural units constituting the resin (A11). More preferably, it is more preferably 60 to 80 mol%. When it is at least the lower limit of the range, moderate alkali solubility is obtained, and the effect of containing the structural unit (a5) is sufficiently obtained. When the amount is not more than the upper limit of the range, the balance with other structural units is good.

The resin (A11) may have only one of the structural units (a1) and (a7), or may have both. As the structural units (a1) and (a7), one type may be used alone, or two or more types may be used in combination.
When the resin (A11) has the structural unit (a1) and does not have the structural unit (a7), the proportion of the structural unit (a1) in the resin (A11) is the entire structural unit constituting the resin (A11). Is preferably 5 to 50 mol%, more preferably 10 to 40 mol%, still more preferably 15 to 35 mol%. When it is at least the lower limit of the range, a pattern can be obtained when the resist composition is used, and when it is at most the upper limit, the balance with other structural units is good.
When the resin (A11) has the structural unit (a7) and does not have the structural unit (a1), the proportion of the structural unit (a7) in the resin (A11) is the entire structural unit constituting the resin (A11). Is preferably 5 to 50 mol%, more preferably 10 to 45 mol%, still more preferably 15 to 40 mol%. When it is at least the lower limit of the range, a pattern can be obtained when the resist composition is used, and when it is at most the upper limit, the balance with other structural units is good.

Moreover, resin (A11) may have structural units other than structural unit (a5), (a1), and (a7) arbitrarily.
Examples of the other structural unit include the structural unit (a6).
When the resin (A11) has the structural unit (a6), the proportion of the structural unit (a6) in the resin (A11) is 1 to 20 mol% with respect to the total of all the structural units constituting the resin (A11). Preferably, 3-15 mol% is more preferable, and 5-15 mol% is further more preferable. The effect by having a structural unit (a6) as it is more than the lower limit of this range is high, and the balance with another structural unit is favorable as it is below an upper limit.
Moreover, resin (A11) may have structural unit (a2)-(a4), (a8) etc. arbitrarily.

  In the present invention, preferred examples of the resin (A11) include, for example, a copolymer having the structural unit (a5) and the structural unit (a1), and a copolymer having the structural unit (a5) and the structural unit (a7). Etc. These copolymers include a copolymer comprising the structural unit (a5) and the structural unit (a1), a copolymer comprising the structural unit (a5) and the structural unit (a7), a structural unit (a5), and the structural unit. Examples thereof include a copolymer composed of (a1) and the structural unit (a6), a copolymer composed of the structural unit (a5), the structural unit (a1) and the structural unit (a7).

"Resin (A12)"
The “acrylic resin” is a resin that includes a structural unit derived from an acrylate ester such as the structural unit (a1) and does not include a styrenic structural unit such as the structural units (a5) to (a7). is there.
In the resin (A12), as the structural unit (a1), one type of structural unit may be used, or two or more types may be used in combination.
In the resin (A12), the proportion of the structural unit (a1) is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, based on the total of all the structural units constituting the resin (A12). More preferred is mol%. By setting it to the lower limit value or more, a pattern can be easily obtained when the resist composition is used, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

The resin (A12) preferably further has a structural unit (a2) in addition to the structural unit (a1).
In the resin (A12), as the structural unit (a2), one type of structural unit may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a2) in the resin (A12) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, with respect to the total of all structural units constituting the resin (A12). 50 mol% is more preferable. By making it the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by making it the upper limit value or less, it is possible to balance with other structural units.

The resin (A12) preferably has a structural unit (a3) in addition to the structural unit (a1) or in addition to the structural unit (a1) and the structural unit (a2).
In the resin (A12), as the structural unit (a3), one type of structural unit may be used alone, or two or more types may be used in combination.
In the resin (A12), the proportion of the structural unit (a3) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, based on the total of all structural units constituting the resin (A12). 5 to 25 mol% is more preferable.

The resin (A12) may optionally have other structural units other than the structural units (a1) to (a3). Examples of the other structural unit include the structural unit (a4).
When the structural unit (a4) is contained in the resin (A12), the ratio is preferably 1 to 30 mol%, more preferably 10 to 20 mol%, based on the total of all the structural units constituting the resin (A12). preferable.

  In the present invention, the resin (A12) is preferably a copolymer having the structural units (a1), (a2) and (a3). Examples of such a copolymer include a copolymer composed of the structural units (a1), (a2) and (a3), and a copolymer composed of the structural units (a1), (a2), (a3) and (a4). A polymer etc. can be illustrated.

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but is preferably 2000 to 50000, more preferably 3000 to 30000, and 5000 to 20000. Most preferred. If it is smaller than the upper limit of this range, there is sufficient solubility in a resist solvent to be used as a resist, and if it is larger than the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
Further, the dispersity (Mw / Mn) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5. In addition, Mn shows a number average molecular weight.

The component (A1) can be obtained by polymerizing a monomer for deriving each structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN).
Further, for the component (A1), in the polymerization, a chain transfer agent such as HS—CH ₂ —CH ₂ —CH ₂ —C (CF ₃ ) ₂ —OH is used in combination, so that the terminal A —C (CF ₃ ) ₂ —OH group may be introduced into the. As described above, a copolymer introduced with a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom reduces development defects and LER (line edge roughness: uneven unevenness of line side walls). It is effective in reducing

[(A2) component]
The component (A2) is preferably a low molecular compound having a molecular weight of 500 or more and less than 4000 and having an acid dissociable, dissolution inhibiting group and a hydrophilic group as exemplified in the description of the component (A1). Specifically, a compound in which a part of hydrogen atoms of a hydroxyl group of a compound having a plurality of phenol skeletons is substituted with the acid dissociable, dissolution inhibiting group can be mentioned.
The component (A2) is, for example, a part of the hydrogen atom of the hydroxyl group of a low molecular weight phenol compound known as a sensitizer in a non-chemically amplified g-line or i-line resist or a heat resistance improver. Those substituted with a soluble dissolution inhibiting group are preferred and can be arbitrarily used.
Examples of such low molecular weight phenol compounds include bis (4-hydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, and bis (4-hydroxy-3-methylphenyl) -3,4-dihydroxy. Phenylmethane, bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) -3,4-dihydroxyphenylmethane, 1 -[1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, bis (2,3, -trihydroxyphenyl) methane, bis (2,4- Dihydroxyphenyl) methane, 2,3,4-trihydroxyphenyl-4′-hydroxy Siphenylmethane, 2- (2,3,4-trihydroxyphenyl) -2- (2 ′, 3 ′, 4′-trihydroxyphenyl) propane, 2- (2,4-dihydroxyphenyl) -2- ( 2 ', 4'-dihydroxyphenyl) propane, 2- (4-hydroxyphenyl) -2- (4'-hydroxyphenyl) propane, 2- (3-fluoro-4-hydroxyphenyl) -2- (3'- Fluoro-4'-hydroxyphenyl) propane, 2- (2,4-dihydroxyphenyl) -2- (4'-hydroxyphenyl) propane, 2- (2,3,4-trihydroxyphenyl) -2- (4 Bisphenol-type conversion such as '-hydroxyphenyl) propane and 2- (2,3,4-trihydroxyphenyl) -2- (4'-hydroxy-3', 5'-dimethylphenyl) propane Compound: Tris (4-hydroxyphenyl) methane, bis (4-hydroxy-3-methylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,3,5-trimethylphenyl) -2-hydroxy Phenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3-hydroxyphenylmethane, bis (4-hydroxy-3) , 5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3-hydroxy Phenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydro Siphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis ( 4-hydroxy-2,5-dimethylphenyl) -2,4-dihydroxyphenylmethane, bis (4-hydroxyphenyl) -3-methoxy-4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-) Methylphenyl) -4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -2- Hydroxyphenylmethane and bis (5-cyclohexyl- Trisphenol type compounds such as -hydroxy-2-methylphenyl) -3,4-dihydroxyphenylmethane; 2,4-bis (3,5-dimethyl-4-hydroxybenzyl) -5-hydroxyphenol, and 2,6 -Linear trinuclear phenol compounds such as bis (2,5-dimethyl-4-hydroxybenzyl) -4-methylphenol; 1,1-bis [3- (2-hydroxy-5-methylbenzyl) -4- Hydroxy-5-cyclohexylphenyl] isopropane, bis [2,5-dimethyl-3- (4-hydroxy-5-methylbenzyl) -4-hydroxyphenyl] methane, bis [2,5-dimethyl-3- (4) -Hydroxybenzyl) -4-hydroxyphenyl] methane, bis [3- (3,5-dimethyl-4-hydroxybenzyl) -4- Hydroxy-5-methylphenyl] methane, bis [3- (3,5-dimethyl-4-hydroxybenzyl) -4-hydroxy-5-ethylphenyl] methane, bis [3- (3,5-diethyl-4-) Hydroxybenzyl) -4-hydroxy-5-methylphenyl] methane, bis [3- (3,5-diethyl-4-hydroxybenzyl) -4-hydroxy-5-ethylphenyl] methane, bis [2-hydroxy-3 -(3,5-dimethyl-4-hydroxybenzyl) -5-methylphenyl] methane, bis [2-hydroxy-3- (2-hydroxy-5-methylbenzyl) -5-methylphenyl] methane, bis [4 -Hydroxy-3- (2-hydroxy-5-methylbenzyl) -5-methylphenyl] methane and bis [2,5-dimethyl-3- (2- Linear type tetranuclear phenol compounds such as droxy-5-methylbenzyl) -4-hydroxyphenyl] methane; 2,4-bis [2-hydroxy-3- (4-hydroxybenzyl) -5-methylbenzyl] -6 -Cyclohexylphenol, 2,4-bis [4-hydroxy-3- (4-hydroxybenzyl) -5-methylbenzyl] -6-cyclohexylphenol, and 2,6-bis [2,5-dimethyl-3- ( 2-hydroxy-5-methylbenzyl) -4-hydroxybenzyl] -4-polyphenols such as linear polyphenol compounds such as 5-nuclear phenol compounds; 1- [1- (4-hydroxyphenyl) isopropyl]- 4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, and 1- [1- (3-methyl-4) Polynuclear branched compounds such as hydroxyphenyl) isopropyl] -4- [1,1-bis (3-methyl-4-hydroxyphenyl) ethyl] benzene; phenols such as phenol, m-cresol, p-cresol or xylenol Examples thereof include 2-12 nuclei of formalin condensate. Of course, it is not limited to these.
The acid dissociable, dissolution inhibiting group is not particularly limited, and examples thereof include those described above.

(A) A component may be used individually by 1 type and may use 2 or more types together.
In the present invention, the component (A) preferably contains the component (A1) because the lithography properties are improved.

<(B) component>
The component (B) is not particularly limited, and those that have been proposed as acid generators for chemically amplified resists can be used. Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, poly (bissulfonyl) diazomethanes, and the like. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.

  As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^１”〜Ｒ^３”，Ｒ^５”〜Ｒ^６”は、それぞれ独立に、置換基を有していてもよいアリール基またはアルキル基を表し；式（ｂ−１）におけるＲ^１”〜Ｒ^３”のうち、いずれか２つが相互に結合して式中のイオウ原子と共に環を形成してもよく；Ｒ^４”は、置換基を有していても良いアルキル基、ハロゲン化アルキル基、アリール基、またはアルケニル基を表し；Ｒ^１”〜Ｒ^３”のうち少なくとも１つはアリール基を表し、Ｒ^５”〜Ｒ^６”のうち少なくとも１つはアリール基を表す。］

[Wherein, R ¹ ″ to R ³ ″ and R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group which may have a substituent; R in the formula (b-1) Any one of ¹ ″ to R ³ ″ may be bonded to each other to form a ring together with the sulfur atom in the formula; R ⁴ ″ represents an alkyl group which may have a substituent, a halogen atom; An alkyl group, an aryl group, or an alkenyl group; at least one of R ¹ ″ to R ³ ″ represents an aryl group, and at least one of R ⁵ ″ to R ⁶ ″ represents an aryl group.]

In formula (b-1), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group which may have a substituent. In addition, any two of R ¹ ″ to R ³ ″ in formula (b-1) may be bonded to each other to form a ring together with the sulfur atom in the formula.
Further, at least one of R ¹ ″ to R ³ ″ represents an aryl group. Of R ¹ ″ to R ³ ″, two or more are preferably aryl groups, and most preferably all R ¹ ″ to R ³ ″ are aryl groups.

The aryl group for R ¹ ″ to R ³ ″ is not particularly limited, and examples thereof include an aryl group having 6 to 20 carbon atoms. The aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
The aryl group may have a substituent. “Having a substituent” means that part or all of the hydrogen atoms of the aryl group are substituted with a substituent, and examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, An alkoxyalkyloxy group, —O—R ⁵⁰ —CO—O—R ^{51 wherein} R ⁵⁰ is an alkylene group and R ⁵¹ is an acid-dissociable group; ] Etc. are mentioned.
The alkyl group that may be substituted for the hydrogen atom of the aryl group is preferably an alkyl group having 1 to 5 carbon atoms, and is a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Is most preferred.
As the alkoxy group that may be substituted for the hydrogen atom of the aryl group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, A tert-butoxy group is preferable, and a methoxy group and an ethoxy group are most preferable.
The halogen atom that may be substituted with the hydrogen atom of the aryl group is preferably a fluorine atom.

As the alkoxyalkyloxy group in which the hydrogen atom of the aryl group may be substituted, for example, —O—C (R ⁴⁷ ) (R ⁴⁸ ) —O—R ^{49 wherein} R ⁴⁷ and R ⁴⁸ are each It is independently a hydrogen atom or a linear or branched alkyl group, R ⁴⁹ is an alkyl group, and R ⁴⁸ and R ⁴⁹ may be bonded to each other to form one ring structure. However, at least one of R ⁴⁷ and R ⁴⁸ is a hydrogen atom. ].
In R ⁴⁷ and R ⁴⁸ , the alkyl group preferably has 1 to 5 carbon atoms, preferably an ethyl group or a methyl group, and most preferably a methyl group.
One of R ⁴⁷ and R ⁴⁸ is preferably a hydrogen atom, the other is preferably a hydrogen atom or a methyl group, and both R ⁴⁷ and R ⁴⁸ are particularly preferably hydrogen atoms.
The alkyl group for R ⁴⁹ preferably has 1 to 15 carbon atoms and may be linear, branched or cyclic.
The linear or branched alkyl group for R ⁴⁹ preferably has 1 to 5 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group. Can be mentioned.
The cyclic alkyl group for R ⁴⁹ preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms.
Specifically, a monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, etc., which may or may not be substituted with an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated alkyl group, etc. And a group obtained by removing one or more hydrogen atoms from the polycycloalkane. Examples of the monocycloalkane include cyclopentane and cyclohexane. Examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
R ⁴⁸ and R ⁴⁹ may be bonded to each other to form one ring structure. In this case, a cyclic group is formed by R ⁴⁸ , R ⁴⁹ , the oxygen atom to which R ⁴⁹ is bonded, and the carbon atom to which the oxygen atom and R ⁴⁸ are bonded. The cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring.

In —O—R ⁵⁰ —CO—O—R ⁵¹ in which the hydrogen atom of the aryl group may be substituted, the alkylene group in R ⁵⁰ is preferably a linear or branched alkylene group, and the carbon number thereof 1-5 are preferable. Examples of the alkylene group include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, and a 1,1-dimethylethylene group.
The acid dissociable group in R ⁵¹ is not particularly limited as long as it is an organic group that can be dissociated by the action of an acid (an acid generated from the component (B) at the time of exposure). Examples include the same acid dissociable, dissolution inhibiting groups. Among them, the tertiary alkyl ester type is preferable.

The alkyl group for R 1 ^{"~R 3",} is not particularly limited, for example, linear C1-10, branched or cyclic alkyl group, and the like. It is preferable that it is C1-C5 from the point which is excellent in resolution. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decanyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.
The alkyl group may have a substituent. “Having a substituent” means that part or all of the hydrogen atoms of the alkyl group are substituted with a substituent, and the substituent may be a substituent that the aryl group may have. The thing similar to what was mentioned as a group is mentioned.

When any two of R ¹ ″ to R ³ ″ in the formula (b-1) are bonded to each other to form a ring together with the sulfur atom in the formula, a 3 to 10 membered ring including the sulfur atom is formed. It is preferable that a 5- to 7-membered ring is formed.
When any two of R ¹ ″ to R ³ ″ in formula (b-1) are bonded to each other to form a ring together with the sulfur atom in the formula, the remaining one may be an aryl group preferable. Examples of the aryl group include the same aryl groups as those described above for R ¹ ″ to R ³ ″.

Of the cation moieties of the compound represented by formula (b-1), when R ¹ ″ to R ³ ″ are all phenyl groups that may have a substituent, that is, the cation moiety is triphenylmethane. Specific examples of preferred skeletons include cation moieties represented by the following formulas (I-1-1) to (I-1-8).
Moreover, what substituted a part or all of the phenyl group in these cation parts with the naphthyl group which may have a substituent is mentioned as a preferable thing. Of the three phenyl groups, 1 or 2 is preferably substituted with the naphthyl group.

Moreover, among the cation part of the compound represented by the formula (b-1), any two of R ¹ ″ to R ³ ″ are bonded to each other to form a ring together with the sulfur atom in the formula. Preferable specific examples of the case include, for example, cation moieties represented by the following formulas (I-1-10) to (I-1-11).
In the following formula (I-1-10), R ⁹ is a phenyl group, a naphthyl group, or an alkyl group having 1 to 5 carbon atoms which may have a substituent.
In the following formula (I-1-11), R ¹⁰ represents a phenyl group, a naphthyl group, an alkyl group having 1 to 5 carbon atoms, an alkoxy group, or a hydroxyl group, which may have a substituent.
u is an integer of 1 to 3, and 1 or 2 is most preferable.

［式中、Ｒ^９は、置換基を有していてもよいフェニル基、ナフチル基または炭素数１〜５のアルキル基であり、Ｒ^１０は、置換基を有していてもよいフェニル基、ナフチル基、炭素数１〜５のアルキル基、アルコキシ基または水酸基であり、ｕは１〜３の整数である。］

[Wherein, R ⁹ is a phenyl group optionally having a substituent, a naphthyl group or an alkyl group having 1 to 5 carbon atoms, and R ¹⁰ is a phenyl group optionally having a substituent, A naphthyl group, an alkyl group having 1 to 5 carbon atoms, an alkoxy group or a hydroxyl group; u is an integer of 1 to 3; ]

R ⁴ ″ represents an alkyl group, a halogenated alkyl group, an aryl group, or an alkenyl group which may have a substituent.
The alkyl group for R ⁴ ″ may be linear, branched or cyclic.
The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
The cyclic alkyl group preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.
Examples of the halogenated alkyl group for R ⁴ ″ include groups in which part or all of the hydrogen atoms of the linear, branched, or cyclic alkyl group have been substituted with halogen atoms. A fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
In the halogenated alkyl group, the ratio of the number of halogen atoms to the total number of halogen atoms and hydrogen atoms contained in the halogenated alkyl group (halogenation rate (%)) is preferably 10 to 100%. 50 to 100% is preferable, and 100% is most preferable. The higher the halogenation rate, the better the acid strength.
The aryl group for R ⁴ ″ is preferably an aryl group having 6 to 20 carbon atoms.
The alkenyl group in R ⁴ ″ is preferably an alkenyl group having 2 to 10 carbon atoms.
In the above R ⁴ ″, “optionally substituted” means one of hydrogen atoms in the linear, branched or cyclic alkyl group, halogenated alkyl group, aryl group, or alkenyl group. It means that part or all may be substituted with a substituent (an atom or group other than a hydrogen atom).
The number of substituents in R ⁴ ″ may be one or two or more.

Examples of the substituent include a halogen atom, a hetero atom, an alkyl group, and a formula: XQ ^1- [wherein Q ¹ is a divalent linking group containing an oxygen atom, and X has a substituent. And a hydrocarbon group having 3 to 30 carbon atoms. ] Etc. which are represented by these.
Examples of the halogen atom and alkyl group include the same groups as those described above for R ⁴ ″ as the halogen atom and alkyl group in the halogenated alkyl group.
Examples of the hetero atom include an oxygen atom, a nitrogen atom, and a sulfur atom.

X-Q 1 ^- In the group represented by, Q ¹ represents a divalent linking group containing an oxygen atom.
Q ¹ may contain an atom other than an oxygen atom. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.
Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond; —O—), an ester bond (—C (═O) —O—), and an amide bond (—C (═O) —NH. -), A carbonyl group (-C (= O)-), a non-hydrocarbon oxygen atom-containing linking group such as a carbonate bond (-O-C (= O) -O-); the non-hydrocarbon oxygen atom Examples include a combination of a containing linking group and an alkylene group.
Examples of the combination include —R ⁹¹ —O—, —R ⁹² —O—C (═O) —, —C (═O) —O—R ⁹³ —, —C (═O) —O—R. ⁹³ —O—C (═O) — (wherein R ^{91 to} R ⁹³ are each independently an alkylene group).
The alkylene group for R ^{91 to} R ⁹³ is preferably a linear or branched alkylene group, and the alkylene group preferably has 1 to 12 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably 1 to 3 carbon atoms. preferable.
Specific examples of the alkylene group include a methylene group [—CH ₂ —]; —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ) ₂ —, —C ( _{CH 3) (CH 2 CH 3} ) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as ethylene group _[-CH 2 CH _2— ]; —CH (CH ₃ ) CH ₂ —, —CH (CH ₃ ) CH (CH ₃ ) —, —C (CH ₃ ) ₂ CH ₂ —, —CH (CH ₂ CH ₃ ) CH ₂ —, Alkylethylene groups such as —CH (CH ₂ CH ₃ ) CH ₂ —; trimethylene group (n-propylene group) [—CH ₂ CH ₂ CH ₂ —]; —CH (CH ₃ ) CH ₂ CH ₂ —, —CH _{2 CH (CH 3) CH 2} - alkyl trimethylene group and the like; Toramechiren group _{[-CH 2 CH 2 CH 2 CH} 2 -]; - CH (CH 3) CH 2 CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 CH 2 - alkyl tetramethylene group and the like; penta And methylene group [—CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ —] and the like.
Q ¹ is preferably a divalent linking group containing an ester bond or an ether bond. Among them, —R ⁹¹ —O—, —R ⁹² —O—C (═O) —, —C (═O) — O—, —C (═O) —O—R ⁹³ — or —C (═O) —O—R ⁹³ —O—C (═O) — is preferred.

In the group represented by XQ ^1- , the hydrocarbon group of X may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.
The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and most preferably 6 to 12. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic hydrocarbon group include a hydrogen atom from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. Aryl groups such as aryl group, benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc., from which one is removed. The number of carbon atoms in the alkyl chain in the arylalkyl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.
The aromatic hydrocarbon group may have a substituent. For example, a part of carbon atoms constituting the aromatic ring of the aromatic hydrocarbon group may be substituted with a hetero atom, and the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group is substituted with the substituent. May be.
Examples of the former include heteroaryl groups in which some of the carbon atoms constituting the ring of the aryl group are substituted with heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and aromatic hydrocarbons in the arylalkyl groups. Examples include heteroarylalkyl groups in which some of the carbon atoms constituting the ring are substituted with the above heteroatoms.
Examples of the substituent of the aromatic hydrocarbon group in the latter example include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
The alkyl group as a substituent of the aromatic hydrocarbon group is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. preferable.
The alkoxy group as a substituent of the aromatic hydrocarbon group is preferably an alkoxy group having 1 to 5 carbon atoms, and is a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, tert- A butoxy group is preferable, and a methoxy group and an ethoxy group are most preferable.
Examples of the halogen atom as a substituent for the aromatic hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent of the aromatic hydrocarbon group include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.

The aliphatic hydrocarbon group for X may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear, branched or cyclic.
In X, the aliphatic hydrocarbon group may have a part of the carbon atoms constituting the aliphatic hydrocarbon group substituted by a substituent containing a hetero atom, and the hydrogen atom constituting the aliphatic hydrocarbon group May be substituted with a substituent containing a hetero atom.
The “heteroatom” in X is not particularly limited as long as it is an atom other than a carbon atom and a hydrogen atom, and examples thereof include a halogen atom, an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom.
The substituent containing a hetero atom may be composed of only the hetero atom, or may be a group containing a group or atom other than the hetero atom.
Specific examples of the substituent for substituting a part of the carbon atom include —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O. —, —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group, an acyl group, etc.), —S—, —S (═O) ₂ —, — S (= O) ₂ —O— and the like can be mentioned. When the aliphatic hydrocarbon group is cyclic, these substituents may be included in the ring structure.
Specific examples of the substituent for substituting part or all of the hydrogen atoms include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), and a cyano group.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group, and a methoxy group or an ethoxy group. Is most preferred.
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
As the halogenated alkyl group, a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc. And a group substituted with a halogen atom.

Examples of the aliphatic hydrocarbon group include a linear or branched saturated hydrocarbon group, a linear or branched monovalent unsaturated hydrocarbon group, or a cyclic aliphatic hydrocarbon group (aliphatic ring). Formula group) is preferred.
The linear saturated hydrocarbon group (alkyl group) preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
The branched saturated hydrocarbon group (alkyl group) preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, Examples include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.

As an unsaturated hydrocarbon group, it is preferable that carbon number is 2-10, 2-5 are preferable, 2-4 are preferable, and 3 is especially preferable. Examples of the linear monovalent unsaturated hydrocarbon group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched monovalent unsaturated hydrocarbon group include a 1-methylpropenyl group and a 2-methylpropenyl group.
Among the above, the unsaturated hydrocarbon group is particularly preferably a propenyl group.

The aliphatic cyclic group may be a monocyclic group or a polycyclic group. The number of carbon atoms is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12.
Specifically, for example, a group in which one or more hydrogen atoms are removed from a monocycloalkane; a group in which one or more hydrogen atoms are removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, etc. Can be mentioned. More specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; one or more polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples include a group excluding a hydrogen atom.
When the aliphatic cyclic group does not contain a substituent containing a hetero atom in the ring structure, the aliphatic cyclic group is preferably a polycyclic group, and has one or more hydrogen atoms from the polycycloalkane. Excluded groups are preferred, and most preferred are groups in which one or more hydrogen atoms have been removed from adamantane.
When the aliphatic cyclic group includes a substituent containing a hetero atom in the ring structure, examples of the substituent containing a hetero atom include —O—, —C (═O) —O—, —S—. , —S (═O) ₂ — and —S (═O) ₂ —O— are preferable. Specific examples of the aliphatic cyclic group include the following formulas (L1) to (L5), (S1) to (S4), and the like.

［式中、Ｑ”は炭素数１〜５のアルキレン基、−Ｏ−、−Ｓ−、−Ｏ−Ｒ^９４−または−Ｓ−Ｒ^９５−であり、Ｒ^９４およびＲ^９５はそれぞれ独立に炭素数１〜５のアルキレン基であり、ｍは０または１の整数である。］

[Wherein, Q ″ is an alkylene group having 1 to 5 carbon atoms, —O—, —S—, —O—R ⁹⁴ — or —S—R ⁹⁵ —, and R ⁹⁴ and R ⁹⁵ are each independently carbon. An alkylene group of 1 to 5 and m is an integer of 0 or 1.]

In the formula, examples of the alkylene group for Q ″, R ⁹⁴ and R ⁹⁵ include the same alkylene groups as those described above for R ^{91 to} R ⁹³ .
In these aliphatic cyclic groups, a part of hydrogen atoms bonded to carbon atoms constituting the ring structure may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
As said alkyl group, a C1-C5 alkyl group is preferable, and it is especially preferable that they are a methyl group, an ethyl group, a propyl group, n-butyl group, and a tert- butyl group.
Examples of the alkoxy group and the halogen atom are the same as those exemplified as the substituent for substituting part or all of the hydrogen atoms.

In the present invention, X is preferably a cyclic group which may have a substituent. The cyclic group may be an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent. It is preferably an aliphatic cyclic group that may be used.
The aromatic hydrocarbon group is preferably a naphthyl group which may have a substituent or a phenyl group which may have a substituent.
As the aliphatic cyclic group which may have a substituent, a polycyclic aliphatic cyclic group which may have a substituent is preferable. The polycyclic aliphatic cyclic group is preferably a group obtained by removing one or more hydrogen atoms from the polycycloalkane, the above (L2) to (L5), (S3) to (S4), and the like.

In the present invention, ^{R 4} ", ^{X-Q 1} - as a substituent preferably has the case, ^{R 4."} The, ^{X-Q 1} -Y 1 - in the Formula, ^{Q 1} and X are the Y ¹ is an optionally substituted alkylene group having 1 to 4 carbon atoms or an optionally substituted fluorinated alkylene group having 1 to 4 carbon atoms. ] Is preferable.
In the group represented by XQ ¹ -Y ^1- , the alkylene group for Y ¹ includes the same alkylene groups as those described above for Q ¹ having 1 to 4 carbon atoms.
Examples of the fluorinated alkylene group include groups in which part or all of the hydrogen atoms of the alkylene group have been substituted with fluorine atoms.
As Y ^1, _{specifically, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF (CF 2 CF 3) -, _{-C (CF 3) 2 -,} - CF 2 CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF ₃ ) —, —C (CF ₃ ) ₂ CF ₂ —, —CF (CF ₂ CF ₃ ) CF ₂ —, —CF (CF ₂ CF ₂ CF ₃ ) —, —C (CF ₃ ) (CF _{2 CF 3) -; - CHF} -, - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -, - CH (CF 3) CH 2 -, - CH (CF 2 _{CF 3) -, - C (} CH 3) (CF 3) -, - CH 2 CH 2 CH 2 CF 2 -, - C H ₂ CH ₂ CF ₂ CF ₂ —, —CH (CF ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CF ₃ ) CH ₂ —, —CH (CF ₃ ) CH (CF ₃ ) —, —C ( _{CF 3) 2 CH 2 -;} - CH 2 -, - CH 2 CH 2 -, - CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 -, - CH (CH 2 CH 3) -, - _{C (CH 3) 2 -,} - CH 2 CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 -, - CH (CH 3) CH _{(CH 3) -, - C} (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - CH (CH 2 CH 2 CH 3) -, - C (CH 3) (CH 2 CH ₃ ) — and the like.

Y ¹ is preferably a fluorinated alkylene group, and particularly preferably a fluorinated alkylene group in which the carbon atom bonded to the adjacent sulfur atom is fluorinated. Examples of such fluorinated alkylene _{group, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF 2 CF 2 CF 2 CF 2 _{-, - CF (CF 3)} CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF 3) -, - C (CF 3) 2 CF 2 -, _{-CF (CF 2 CF 3) CF} 2 -; - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -; - CH 2 CH 2 CH 2 CF 2 -, - CH ₂ CH ₂ CF ₂ CF ₂ —, —CH ₂ CF ₂ CF ₂ CF ₂ — and the like can be mentioned.
Of _{these, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, or _CH 2 _CF 2 CF ₂ - is _{preferable, -CF 2 -, - CF 2} CF 2 - or -CF ₂ CF ₂ CF ₂ - is more preferable, -CF ₂ - is particularly preferred.

The alkylene group or fluorinated alkylene group may have a substituent. An alkylene group or a fluorinated alkylene group has a “substituent” means that part or all of the hydrogen atom or fluorine atom in the alkylene group or fluorinated alkylene group is substituted with an atom or group other than a hydrogen atom and a fluorine atom. Means that
Examples of the substituent that the alkylene group or fluorinated alkylene group may have include an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a hydroxyl group.

In formula (b-2), R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group. At least one of R ⁵ ″ to R ⁶ ″ represents an aryl group. It is preferable that all of R ⁵ ″ to R ⁶ ″ are aryl groups.
As the aryl group for R ⁵ ″ to R ⁶ ″, the same as the aryl groups for R ¹ ″ to R ³ ″ can be used.
Examples of the alkyl group for R ⁵ ″ to R ⁶ ″ include the same as the alkyl group for R ¹ ″ to R ³ ″.
Among these, it is most preferable that all of R ⁵ ″ to R ⁶ ″ are phenyl groups.
"As ^{R 4} in the formula (b-1)" ^{R 4} in the In the formula (b-2) include the same as.

Specific examples of the onium salt acid generators represented by formulas (b-1) and (b-2) include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate; bis (4-tert-butylphenyl) iodonium. Trifluoromethane sulfonate or nonafluorobutane sulfonate; triphenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; tri (4-methylphenyl) sulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its Nonafluorobutanesulfonate; dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethanesulfonate, its heptaful Lopropane sulfonate or its nonafluorobutane sulfonate; trifluoromethane sulfonate of monophenyldimethylsulfonium, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; trifluoromethane sulfonate of diphenyl monomethylsulfonium, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate (4-methylphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; (4-methoxyphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; Trifluoromethanesulfonate of tri (4-tert-butyl) phenylsulfonium, its heptafluoropropane sulfonate or its nonafluorobutanesulfonate; trifluoromethanesulfonate of diphenyl (1- (4-methoxy) naphthyl) sulfonium, its heptafluoropropane Sulfonate or its nonafluorobutane sulfonate; trifluoromethane sulfonate of di (1-naphthyl) phenylsulfonium, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1-phenyltetrahydrothiophenium trifluoromethane sulfonate, its heptafluoropropane sulfonate Or nonafluorobutanesulfonate thereof; 1- (4-methylphenyl) ) Tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1- (4-ethoxynaphthalene-1- Yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonaflu 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1-phenyltetrahydrothiopyranium trifluoromethanesulfonate , Its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl -4-Hydroxyphenyl) tetrahydrothiopyranium trifluoromethanesulfonate, its heptafluoropropanes Honeto or nonafluorobutanesulfonate; 1- (4-methylphenyl) trifluoromethanesulfonate tetrahydrothiophenium Pila chloride, heptafluoropropane sulfonate or its nonafluorobutane sulfonate, and the like.
Moreover, the onium salt which replaced the anion part of these onium salts with alkyl sulfonates, such as methanesulfonate, n-propanesulfonate, n-butanesulfonate, n-octanesulfonate, can also be used.
Moreover, the onium salt which replaced the anion part of these onium salts by the anion part represented by either of following formula (b1)-(b8) can also be used.

［式中、ｐは１〜３の整数であり、ｖ０は０〜３の整数であり、ｑ１〜ｑ２はそれぞれ独立に１〜５の整数であり、ｑ３は１〜１２の整数であり、ｒ１〜ｒ２はそれぞれ独立に０〜３の整数であり、ｇは１〜２０の整数であり、ｔ３は１〜３の整数であり、Ｒ^７は置換基である。］

[Wherein, p is an integer of 1 to 3, v0 is an integer of 0 to 3, q1 to q2 are each independently an integer of 1 to 5, q3 is an integer of 1 to 12, and r1 ~r2 are each independently an integer of 0 to 3, g is an integer of 1 to 20, t3 is an integer from 1 to 3, ^{R 7} is a substituent. ]

［式中、ｐ、Ｒ^７、Ｑ”はそれぞれ前記と同じであり、ｎ１〜ｎ５はそれぞれ独立に０または１であり、ｖ１〜ｖ５はそれぞれ独立に０〜３の整数であり、ｗ１〜ｗ５はそれぞれ独立に０〜３の整数である。］

[Wherein, p, R ⁷ and Q ″ are the same as defined above, n1 to n5 are each independently 0 or 1, v1 to v5 are each independently an integer of 0 to 3, w1 to w5 Are each independently an integer of 0 to 3.]

Examples of the substituent for R ⁷ are the same as those described above as the substituent that the aliphatic hydrocarbon group may have and the substituent that the aromatic hydrocarbon group may have in X. Can be mentioned.
Code (r1 and r2, w1 to w5) attached to R ⁷ when is an integer of 2 or more, a plurality of the ^{R 7} groups may be the same, respectively, may be different.
r1 to r2 and w1 to w5 are each preferably an integer of 0 to 2, and more preferably 0 or 1.
v0 to v5 are preferably 0 to 2, and most preferably 0 or 1.
t3 is preferably 1 or 2, and most preferably 1.
q3 is preferably 1 to 5, more preferably 1 to 3, and most preferably 1.

  Moreover, as an onium salt type | system | group acid generator, in the said general formula (b-1) or (b-2), an anion part is represented by the following general formula (b-3) or (b-4). An onium salt-based acid generator replaced with can also be used (the cation moiety is the same as (b-1) or (b-2)).

［式中、Ｘ”は、少なくとも１つの水素原子がフッ素原子で置換された炭素数２〜６のアルキレン基を表し；Ｙ”、Ｚ”は、それぞれ独立に、少なくとも１つの水素原子がフッ素原子で置換された炭素数１〜１０のアルキル基を表す。］

[Wherein X ″ represents an alkylene group having 2 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom; Y ″ and Z ″ each independently represent at least one hydrogen atom as a fluorine atom; Represents an alkyl group having 1 to 10 carbon atoms and substituted with

X ″ is a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkylene group has 2 to 6 carbon atoms, preferably 3 to 5 carbon atoms, Most preferably, it has 3 carbon atoms.
Y ″ and Z ″ are each independently a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkyl group has 1 to 10 carbon atoms, preferably Has 1 to 7 carbon atoms, more preferably 1 to 3 carbon atoms.
The carbon number of the alkylene group of X ″ or the carbon number of the alkyl group of Y ″ and Z ″ is preferably as small as possible because the solubility in the resist solvent is good within the above carbon number range.
In addition, in the alkylene group of X ″ or the alkyl group of Y ″ and Z ″, as the number of hydrogen atoms substituted with fluorine atoms increases, the strength of the acid increases, and high-energy light or electron beam of 200 nm or less The ratio of fluorine atoms in the alkylene group or alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all. Are a perfluoroalkylene group or a perfluoroalkyl group in which a hydrogen atom is substituted with a fluorine atom.

  Moreover, the sulfonium salt which has a cation part represented by the following general formula (b-5) or (b-6) can also be used as an onium salt type | system | group acid generator.

［式中、Ｒ^４１〜Ｒ^４６はそれぞれ独立してアルキル基、アセチル基、アルコキシ基、カルボキシ基、水酸基またはヒドロキシアルキル基であり；ｎ_１〜ｎ_５はそれぞれ独立して０〜３の整数であり、ｎ_６は０〜２の整数である。］

[Wherein R ^{41 to} R ⁴⁶ are each independently an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxyl group or hydroxyalkyl group; n _{1 to} n ₅ are each independently an integer of 0 to 3; There, _{n 6} is an integer of 0-2. ]

In R ^{41 to} R ⁴⁶ , the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group, and a methyl group, an ethyl group, a propyl group, an isopropyl group, n A butyl group or a tert-butyl group is particularly preferable.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a linear or branched alkoxy group, and particularly preferably a methoxy group or an ethoxy group.
The hydroxyalkyl group is preferably a group in which one or more hydrogen atoms in the alkyl group are substituted with a hydroxy group, and examples thereof include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.
When the symbols n _{1 to} n ₆ attached to R ^{41 to} R ⁴⁶ are integers of 2 or more, the plurality of R ^{41 to} R ⁴⁶ may be the same or different.
n ₁ is preferably 0 to 2, more preferably 0 or 1, and still more preferably 0.
n ₂ and n ₃ are preferably each independently 0 or 1, more preferably 0.
n ₄ is preferably 0 to 2, more preferably 0 or 1.
n ₅ is preferably 0 or 1, more preferably 0.
n ₆ is preferably 0 or 1, more preferably 1.

The anion part of the sulfonium salt having a cation part represented by the formula (b-5) or (b-6) is not particularly limited, and is the same as the anion part of the onium salt acid generators proposed so far. It may be a thing. Examples of the anion moiety include fluorinated alkyl sulfonate ions such as the anion moiety (R ⁴ ″ SO ₃ ⁻ ) of the onium salt acid generator represented by the general formula (b-1) or (b-2). The anion part represented by the general formula (b-3) or (b-4) and the like.

  In this specification, the oxime sulfonate acid generator is a compound having at least one group represented by the following general formula (B-1), and has a property of generating an acid upon irradiation with radiation. is there. Such oxime sulfonate-based acid generators are frequently used for chemically amplified resist compositions, and can be arbitrarily selected and used.

（式（Ｂ−１）中、Ｒ^３１、Ｒ^３２はそれぞれ独立に有機基を表す。）

(In formula (B-1), R ³¹ and R ³² each independently represents an organic group.)

The organic groups of R ³¹ and R ³² are groups containing carbon atoms, and atoms other than carbon atoms (for example, hydrogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms (fluorine atoms, chlorine atoms, etc.), etc.) You may have.
As the organic group for R ^31, a linear, branched, or cyclic alkyl group or aryl group is preferable. These alkyl groups and aryl groups may have a substituent. There is no restriction | limiting in particular as this substituent, For example, a fluorine atom, a C1-C6 linear, branched or cyclic alkyl group etc. are mentioned. Here, “having a substituent” means that part or all of the hydrogen atoms of the alkyl group or aryl group are substituted with a substituent.
As an alkyl group, C1-C20 is preferable, C1-C10 is more preferable, C1-C8 is more preferable, C1-C6 is especially preferable, and C1-C4 is the most preferable. As the alkyl group, a partially or completely halogenated alkyl group (hereinafter sometimes referred to as a halogenated alkyl group) is particularly preferable. The partially halogenated alkyl group means an alkyl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated alkyl group means that all of the hydrogen atoms are halogen atoms. Means an alkyl group substituted with Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. That is, the halogenated alkyl group is preferably a fluorinated alkyl group.
The aryl group preferably has 4 to 20 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms. As the aryl group, a partially or completely halogenated aryl group is particularly preferable. The partially halogenated aryl group means an aryl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated aryl group means that all of the hydrogen atoms are halogen atoms. Means an aryl group substituted with.
R ³¹ is particularly preferably an alkyl group having 1 to 4 carbon atoms having no substituent or a fluorinated alkyl group having 1 to 4 carbon atoms.
As the organic group for R ^32, a linear, branched, or cyclic alkyl group, aryl group, or cyano group is preferable. As the alkyl group and aryl group for R ^32, the same alkyl groups and aryl groups as those described above for R ³¹ can be used.
R ³² is particularly preferably a cyano group, an alkyl group having 1 to 8 carbon atoms having no substituent, or a fluorinated alkyl group having 1 to 8 carbon atoms.

  More preferable examples of the oxime sulfonate-based acid generator include compounds represented by the following general formula (B-2) or (B-3).

［式（Ｂ−２）中、Ｒ^３３は、シアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３４はアリール基である。Ｒ^３５は置換基を有さないアルキル基またはハロゲン化アルキル基である。］

[In Formula (B-2), R ³³ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁴ is an aryl group. R ³⁵ represents an alkyl group having no substituent or a halogenated alkyl group. ]

［式（Ｂ−３）中、Ｒ^３６はシアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３７は２または３価の芳香族炭化水素基である。Ｒ^３８は置換基を有さないアルキル基またはハロゲン化アルキル基である。ｐ”は２または３である。］

[In Formula (B-3), R ³⁶ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁷ is a divalent or trivalent aromatic hydrocarbon group. ^R38 is an alkyl group having no substituent or a halogenated alkyl group. p ″ is 2 or 3.]

In the general formula (B-2), the alkyl group or halogenated alkyl group having no substituent of R ³³ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and carbon atoms. Numbers 1 to 6 are most preferable.
R ³³ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³³ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred.
As the aryl group of R ³⁴ , one hydrogen atom is removed from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, or a phenanthryl group. And a heteroaryl group in which a part of carbon atoms constituting the ring of these groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Among these, a fluorenyl group is preferable.
The aryl group of R ³⁴ may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, or an alkoxy group. The alkyl group or halogenated alkyl group in the substituent preferably has 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. The halogenated alkyl group is preferably a fluorinated alkyl group.
The alkyl group or halogenated alkyl group having no substituent of R ³⁵ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 6 carbon atoms.
R ³⁵ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³⁵ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred is the strength of the acid generated. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted.

In the general formula (B-3), the alkyl group or halogenated alkyl group having no substituent for R ³⁶ is the same as the alkyl group or halogenated alkyl group having no substituent for R ^33. Is mentioned.
Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁷ include groups obtained by further removing one or two hydrogen atoms from the aryl group for R ³⁴ .
Examples of the alkyl group or halogenated alkyl group having no substituent of R ³⁸ include the same alkyl groups or halogenated alkyl groups as those having no substituent of R ³⁵ .
p ″ is preferably 2.

Specific examples of the oxime sulfonate acid generator include α- (p-toluenesulfonyloxyimino) -benzyl cyanide, α- (p-chlorobenzenesulfonyloxyimino) -benzyl cyanide, α- (4-nitrobenzenesulfonyloxy). Imino) -benzylcyanide, α- (4-nitro-2-trifluoromethylbenzenesulfonyloxyimino) -benzylcyanide, α- (benzenesulfonyloxyimino) -4-chlorobenzylcyanide, α- (benzenesulfonyl) Oxyimino) -2,4-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -2,6-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -4-methoxybenzyl cyanide, α- ( 2-Chlorobenzenesulfonyloxyimino) 4-methoxybenzylcyanide, α- (benzenesulfonyloxyimino) -thien-2-ylacetonitrile, α- (4-dodecylbenzenesulfonyloxyimino) -benzylcyanide, α-[(p-toluenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α-[(dodecylbenzenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α- (tosyloxyimino) -4-thienyl cyanide, α- (methylsulfonyloxyimino) -1-cyclo Pentenyl acetonitrile, α- (methylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -1-cycloheptenylacetonitrile, α- (methylsulfonyloxyimino) -1-cyclooctene Acetonitrile, α- (trifluoromethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -cyclohexylacetonitrile, α- (ethylsulfonyloxyimino) -ethylacetonitrile, α- (propyl Sulfonyloxyimino) -propylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclopentylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclohexylacetonitrile, α- (cyclohexylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- ( Ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclope Nthenyl acetonitrile, α- (n-butylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (ethylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclohexenylacetonitrile , Α- (n-butylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -phenylacetonitrile, α- (methylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (trifluoro Methylsulfonyloxyimino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -p- Butoxy phenylacetonitrile, alpha-(propylsulfonyl oxyimino)-p-methylphenyl acetonitrile, alpha-like (methylsulfonyloxyimino)-p-bromophenyl acetonitrile.
Further, an oxime sulfonate-based acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014] [chemical formula 18] to [chemical formula 19]), WO2004 / 074242A2 (pages 65 to 85). The oxime sulfonate acid generators disclosed in Examples 1 to 40) of No. 1 can also be suitably used.
Moreover, the following can be illustrated as a suitable thing.

Among diazomethane acid generators, specific examples of bisalkyl or bisarylsulfonyldiazomethanes include bis (isopropylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, Examples include bis (cyclohexylsulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane, and the like.
Further, diazomethane acid generators disclosed in JP-A-11-035551, JP-A-11-035552, and JP-A-11-035573 can also be suitably used.
Examples of poly (bissulfonyl) diazomethanes include 1,3-bis (phenylsulfonyldiazomethylsulfonyl) propane and 1,4-bis (phenylsulfonyldiazo) disclosed in JP-A-11-322707. Methylsulfonyl) butane, 1,6-bis (phenylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (phenylsulfonyldiazomethylsulfonyl) decane, 1,2-bis (cyclohexylsulfonyldiazomethylsulfonyl) ethane, 1,3 -Bis (cyclohexylsulfonyldiazomethylsulfonyl) propane, 1,6-bis (cyclohexylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (cyclohexylsulfonyldiazomethylsulfonyl) decane, etc. Door can be.

(B) As a component, these acid generators may be used individually by 1 type, and may be used in combination of 2 or more type.
In the present invention, it is particularly preferable to use an onium salt having a fluorinated alkyl sulfonate ion as an anion as the component (B).
In the resist composition, the content of the component (B) is preferably 0.5 to 50 parts by mass and more preferably 1 to 40 parts by mass with respect to 100 parts by mass of the component (A). By setting it within the above range, pattern formation is sufficiently performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

<Optional component>
A nitrogen-containing organic compound component (D) (hereinafter referred to as “component (D)”) can be added to the resist composition as an optional component.
The component (D) is not particularly limited as long as it acts as an acid diffusion control agent, that is, a quencher that traps the acid generated from the component (B) by exposure, and a wide variety of components have already been proposed. Therefore, any known one may be used, and aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are particularly preferable. An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of the aliphatic amine include an amine (alkyl amine or alkyl alcohol amine) or a cyclic amine in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms.
Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di- -Dialkylamines such as n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-hexylamine, tri-n-pentylamine , Tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, tri-n-dodecylamine, etc .; diethanolamine, triethanolamine, diisopropanolamine Triisopropanolamine, di -n- octanol amines, alkyl alcohol amines tri -n- octanol amine. Among these, a trialkylamine having 5 to 10 carbon atoms is more preferable, and a tri-n-alkylamine having 5 to 10 carbon atoms is most preferable.
Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable. Specifically, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5. 4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane, and the like.
These may be used alone or in combination of two or more.
(D) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component. By setting the content in the above range, the resist pattern shape, the stability over time, and the like are improved.

In addition, the resist composition includes, as an optional component, a group consisting of an organic carboxylic acid and a phosphorus oxo acid and derivatives thereof for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, retention stability over time, and the like. At least one compound (E) selected from (hereinafter referred to as component (E)) can be contained.
As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.
Examples of phosphorus oxo acids and derivatives thereof include phosphoric acid, phosphonic acid, phosphinic acid and the like, and among these, phosphonic acid is particularly preferable.
Examples of the oxo acid derivative of phosphorus include esters in which the hydrogen atom of the oxo acid is substituted with a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 5 carbon atoms and 6 to 6 carbon atoms. 15 aryl groups and the like.
Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
Examples of phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.
Examples of the phosphinic acid derivatives include phosphinic acid esters such as phenylphosphinic acid.
(E) A component may be used individually by 1 type and may use 2 or more types together.
As the component (E), an organic carboxylic acid is preferable, and salicylic acid is particularly preferable.
(E) A component is used in the ratio of 0.01-5.0 mass parts per 100 mass parts of (A) component.

  If desired, the resist composition may further contain miscible additives, for example, additional resins for improving the performance of the resist film, surfactants for improving coatability, dissolution inhibitors, plasticizers, and stabilizers. A coloring agent, a coloring agent, an antihalation agent, a dye, and the like can be appropriately added and contained. In addition, when the resist pattern is formed by immersion exposure, for example, a fluorine-based additive as described in JP-A-2008-134607 can be contained.

The resist composition can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as (S) component).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Conventionally, any one or more of known resist solvents can be used. It can be appropriately selected and used.
For example, lactones such as γ-butyrolactone;
Ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, 2-heptanone;
Polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol;
Compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, monomethyl ether, monoethyl ether, monopropyl of the polyhydric alcohols or the compound having an ester bond Derivatives of polyhydric alcohols such as ethers, monoalkyl ethers such as monobutyl ether or compounds having an ether bond such as monophenyl ether [in these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME) Is preferred];
Cyclic ethers such as dioxane and esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate;
Aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. be able to.

These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and EL are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is also preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range.
More specifically, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3.
In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.

In the pattern formation method, when the resist pattern is formed by a double patterning process, the second resist composition is applied onto the first resist pattern, so that the (S) component of the second resist composition is used. It is preferable to use an organic solvent that does not dissolve the first resist pattern. Examples of the organic solvent include the same solvents as those described above for the component (S ′) of the material for forming a reverse pattern of the present invention.
However, in this case, as the (S ′) component of the material for forming an inverted pattern, it is used for these resist compositions so that both the first resist pattern and the resist pattern formed with the second resist composition are not dissolved. It is preferable to use a different organic solvent. For example, when an alcohol-based organic solvent is used as the (S) component of the second resist composition, an ether-based organic solvent having no hydroxyl group is preferably used as the (S ′) component of the reversal pattern forming material.

  The amount of the component (S) used is not particularly limited, but is a concentration that can be applied to a substrate or the like and is appropriately set according to the coating film thickness. In general, the solid content concentration of the resist composition is 0. .5 to 20% by mass, preferably 1 to 15% by mass.

  As described above, the chemically amplified resist composition has been described in detail, but the present invention is not limited thereto. For example, the resist composition (non-chemically amplified resist composition) containing no component (B) ( You may mix | blend and use B) component. As the non-chemically amplified resist composition, those conventionally proposed as radiation-sensitive compositions can be used, such as alkali-soluble resins such as novolak resins and hydroxystyrene resins, and naphthoquinonediazide group-containing compounds. And a resist composition containing a photosensitive component. The resist composition may contain a sensitizer as necessary.

≪Material for resist coating film formation≫
The material for forming a resist coating film used in the coating pattern forming method of the present invention includes a silicon-containing polymer (hereinafter sometimes referred to as (X ′) component) capable of causing a crosslinking reaction by the action of an acid, and the silicon-containing material. It contains an organic solvent that dissolves the polymer (hereinafter sometimes referred to as (S ′) component).
In such a material for forming a resist coating film, by containing the component (X ′), it can be cured by the action of an acid generated from the component (B) contained in the resist pattern.
Therefore, in the coating pattern forming method of the present invention, when the resist coating film forming material is applied to form a coating film on the resist pattern and exposed and / or baked, it is included in the resist pattern ( B) Due to the action of the acid generated from the component, the crosslinking reaction proceeds from the portion in contact with the resist pattern, and the resist coating film forming material is cured to form a resist coating film that covers the surface of the resist pattern. can do.
In addition, the coating film formed in this way was subjected to etching under a sufficient etching selectivity ratio (for example, an organic material such as a resist pattern) to be removed by etching in a pattern forming method described later (for example, etching was performed under the same conditions). Difference in etching rate at the time) and sufficiently functions as an etching mask.
In the present invention, the resist coating film forming material preferably does not contain the component (B). As a result, the crosslinking reaction proceeds from the portion in contact with the resist pattern, so that the uniformity of the film thickness of the resist coating film formed on the resist pattern surface is improved. However, the present invention is not limited to this, and the resist coating film forming material may contain the component (B) as long as the effects of the present invention are not impaired.

[(X ′) component]
A “silicon-containing polymer” is a polymer that contains silicon atoms in its structure. The type of the silicon-containing polymer is not particularly limited, and may include a group containing a silicon atom in the side chain (for example, an alkylsilyl group, a group containing a —Si—O— bond), and a silicon atom in the main chain. May be included. Examples of the former include those in which a group containing a silicon atom is introduced into the side chain, such as a novolak resin, a hydroxystyrene resin, and an acrylic resin. Examples of the latter include silicone resin, polysilane, polycarbosilane and the like.
In the present invention, among these, a silicone resin is preferable from the viewpoint of etching resistance.

In the present invention, the component (X ′) needs to have acid crosslinkability capable of causing a crosslinking reaction by the action of an acid. From such a viewpoint, the component (X ′) preferably has a group having acid crosslinkability (hereinafter referred to as an acid crosslinkable group) capable of undergoing a crosslinking reaction by the action of an acid.
Specific examples of the acid crosslinking group include, for example, a group containing an ethylenically unsaturated double bond (> C = C <) (an ethylenically unsaturated double bond-containing group), an epoxy group-containing group, and a phenolic hydroxyl group. And alcoholic hydroxyl groups.

  As an ethylenically unsaturated double bond containing group, what has an ethylenically unsaturated double bond at the terminal is preferable, and especially the group represented by the following general formula (I) is preferable.

［式中、Ｒ^ａ、Ｒ^ｂおよびＲ^ｃはそれぞれ独立に水素原子、アルキル基またはハロゲン化アルキル基であり、Ｒ^ｂおよびＲ^ｃが相互に結合して環を形成していてもよく、Ｗは単結合または２価の連結基である。］

[Wherein, R ^a , R ^b and R ^c are each independently a hydrogen atom, an alkyl group or a halogenated alkyl group, and R ^b and R ^c may be bonded to each other to form a ring; Is a single bond or a divalent linking group. ]

The alkyl group in R ^a , R ^b and R ^c is preferably an alkyl group having 1 to 5 carbon atoms. Specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert group -Linear or branched alkyl groups, such as a butyl group, a pentyl group, an isopentyl group, and a neopentyl group.
As the halogenated alkyl group, a halogenated alkyl group having 1 to 5 carbon atoms is preferable, and specific examples include a group in which part or all of the hydrogen atoms of the alkyl group are substituted with a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
In the formula (I), R ^a and R ^b are preferably hydrogen atoms.
R ^c is preferably a hydrogen atom, an alkyl group or a fluorinated alkyl group, and most preferably a hydrogen atom or a methyl group in view of industrial availability.
The alkyl group or halogenated alkyl group in R ^a , R ^b and R ^c each may have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a hydroxyl group, a carboxy group, and an oxygen atom (═O).
In formula (I), R ^b and R ^c may be bonded to each other to form a ring. In this case, a part of carbon atoms constituting the ring skeleton of the ring may be substituted with an etheric oxygen atom (—O—).

Examples of the divalent linking group for W include the same groups as those described above for Y ² in the general formula (a1-0-2) given in the description of the structural unit (a1) of the component (A) of the resist composition. .
In the present invention, the divalent linking group for W is particularly preferably one containing a carbonyloxy group, and the carbon atom of the carbonyl group in the carbonyloxy group is the carbon to which R ^c in the formula (I) is bonded. It is preferably directly bonded to the atom.
As the divalent linking group containing a carbonyloxy group, —C (═O) —O— (R ^d —O) _n — [wherein R ^d is an alkylene group, and n is an integer of 0 to 10. is there. ], —C (═O) —O—R ^d1 —O—C (═O) —R ^d2 —O—, wherein R ^d1 and R ^d2 are each independently an alkylene group. ] Etc. are mentioned. Among these, —C (═O) —O— (R ^d —O) _n — is preferable.
As the alkylene group for R ^d , R ^d1 and R ^d2, an alkylene group having 1 to 10 carbon atoms is preferable, and an ethylene group or a propylene group is particularly preferable.
n is the number of added moles of the alkylene oxide group (R ^d —O), preferably an integer of 0 to 6, more preferably an integer of 0 to 4, and most preferably 0. That is, W is most preferably —C (═O) —O—.

  Examples of the epoxy group-containing group include the following formulas (e1) to (e4).

  The component (X ′) may have the acid cross-linking group as described above on the side chain, at the end of the main chain, or on both. From the viewpoint of curability, it is preferable to have an acid crosslinking group in the side chain.

In addition, the component (X ′) needs to be soluble in the developer used in the development process in order to remove the uncured (uncrosslinked) portion by the development process in the step (iv) of the coating pattern forming method. is there. From this point of view, the component (X ′) preferably has a group (hereinafter referred to as a development soluble group) having an action (development solubility) for enhancing solubility in the developer.
The development-soluble group is not particularly limited as long as it has the above-mentioned development solubility, and may be appropriately set according to the type of developer used for the development process. For example, when an alkali developer is used as the developer, the development soluble group preferably includes a phenolic hydroxyl group, an alcoholic hydroxyl group, a hydrogen atom (Si-H) directly bonded to a silicon atom, a carboxy group, and the like.
In the case where an organic solvent (preferably an alcohol solvent) is used as the developer, it is not limited to the above-mentioned substituents. Therefore, hereinafter, when simply referred to as “development soluble”, it means alkali development solubility. .

  The component (X ′) may have a development-soluble group as described above in the side chain, may be present at the end of the main chain, or may be present in both. From the viewpoint of solubility, it is preferable to have a development soluble group in the side chain.

However, when the component (X ′) uses a group having both acid crosslinkability and development solubility (development soluble / acid crosslinking group) as the acid crosslinking group, the development soluble / acid crosslinking There may be no development-soluble group other than the group.
Examples of the development-soluble / acid-crosslinking group include a phenolic hydroxyl group and an alcoholic hydroxyl group.

In the present invention, the (X ′) component preferably used includes the following (X′1) component, (X′2) component and the like.
Component (X′1): A silicone resin having a development-soluble / acid-crosslinking group in the side chain.
Component (X′2): a silicone resin having an acid crosslinking group and a development-soluble group that do not have development solubility in the side chain.
Hereinafter, the component (X′1) and the component (X′2) will be described in more detail.

[(X′1) component]
As the component (X′1), those having a phenolic hydroxyl group and / or an alcoholic hydroxyl group in the side chain are particularly preferred.
The component (X′1) may optionally further have a crosslinking group and / or a development soluble group that does not have development solubility.
Preferable (X′1) component includes those having the structural unit (x1) shown below.

-Structural unit (x1):
The structural unit (x1) is a structural unit represented by the following formula (x1-11).

［式中、Ｒ^１は、置換基として現像可溶・酸架橋基を有するアルキル基、アリール基またはアラルキル基である。］

[Wherein, R ¹ represents an alkyl group, aryl group or aralkyl group having a development-soluble / acid-crosslinking group as a substituent. ]

In formula (x1-11), the alkyl group, aryl group or aralkyl group in R ¹ has “developable solubility / acid crosslinking group as a substituent” means hydrogen in the alkyl group, aryl group or arylalkyl group It means that the atom is substituted with a development soluble / acid bridging group.
The development-soluble / acid-crosslinking group in R ¹ is preferably a hydroxyl group (phenolic hydroxyl group, alcoholic hydroxyl group). When the hydroxyl group is bonded to the alkyl chain portion in the alkyl group or aralkyl group, the hydroxyl group is an alcoholic hydroxyl group, and when bonded to the aromatic ring of the aryl group or aralkyl group, it is a phenolic hydroxyl group.
The number of development-soluble / acid-crosslinking groups in R ¹ is preferably 1 to 3, more preferably 1 to 2, and most preferably 1.

The alkyl group for R ¹ may be linear, branched or cyclic, preferably linear or branched, and particularly preferably linear. 1-5 are preferable and, as for carbon number of this alkyl group, 1-3 are more preferable. However, the carbon number does not include the carbon number in the substituent. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. Among these, a methyl group, an ethyl group, or an n-propyl group is preferable.
The alkyl group may have a substituent other than the hydroxyl group. Examples of the other substituent include an alkoxy group, a halogen atom, a halogenated alkyl group, a thiol group (—SH), an alkylthio group (—S—R [R is an alkyl group]), an oxygen atom (= O), an ester group (—C (═O) —O—R [R is an alkyl group]), a cyano group, an amino group, an amide group, a carboxy group, —SO ₃ R ¹⁰¹ [R ¹⁰¹ is an alkyl group. It is. _{^{], - (O-R 103}} ) c -OR 102 [R 102 is an alkyl ^{group, R 103} is an alkylene radical, c is an integer of 1 to 10. ] Etc. are mentioned.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group, and a methoxy group or an ethoxy group. Is most preferred.
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
As the halogenated alkyl group, a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc. And a group substituted with a halogen atom.
The alkylthio group is preferably an alkylthio group having 1 to 5 carbon atoms, preferably a methylthio group, an ethylthio group, an n-propylthio group, an iso-propylthio group, an n-butylthio group, or a tert-butylthio group, and a methylthio group or an ethylthio group. Is most preferred.
As the ester group, an alkyl ester group having 1 to 5 carbon atoms of an alkyl group is preferable, and a methyl ester group, an ethyl ester group, an n-propyl ester group, an iso-propyl ester group, an n-butyl ester group, a tert- A butyl ester group is preferred, and a methyl ester group is most preferred.
As the amide group, the two substituents bonded to nitrogen are preferably independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and the alkyl group is the same as above. The alkyl groups may be bonded to each other to form a ring, in which case a 5-membered ring or a 6-membered ring is preferred.
The alkyl group of ^{R 101} in -SO ₃ R ^101, include those same alkyl groups as the alkyl group for ^{R 1.}
- Examples of the alkyl group _{^{(O-R 103) c R}} 102 of ^{-OR 102,} include those same alkyl groups as the alkyl group for ^{R 1.}
As the alkylene group for R ^103, an alkylene group having 1 to 6 carbon atoms is preferable, and an ethylene group or a propylene group is particularly preferable.
c is the number of added moles of the alkylene oxide group (O—R ¹⁰³ ), preferably an integer of 1 to 8, and more preferably an integer of 1 to 5.

The aryl group in R ¹ preferably has 3 to 30 carbon atoms, more preferably 5 to 30, more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aryl group include a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group.
The aryl group may have a substituent other than the hydroxyl group. Examples of the other substituents include groups exemplified as the substituents that the alkyl group may have, alkyl groups, and the like.
The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.

The aralkyl group in R ^1, for example, those in which some of the hydrogen atoms of the alkyl group for R ¹ described above is substituted by an aryl group for R ¹ described above. The carbon number of the alkyl chain in the aralkyl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.
Specific examples of the aralkyl group include a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, and a 2-naphthylethyl group.
The aralkyl group may have a substituent other than the hydroxyl group. Examples of the other substituent include the same substituents as those described above as the substituents that the alkyl group and aryl group may have.

R ¹ is preferably an aryl group or aralkyl group having a hydroxyl group, particularly a phenyl group or benzyl group having a hydroxyl group, from the viewpoint of excellent etching resistance of the coating film to be formed, control of coating pattern dimensions, developability, and the like. preferable.

In the component (X′1), as the structural unit (x1), one type may be used alone, or two or more types may be used in combination.
In the component (X′1), the proportion of the structural unit (x1) may be 100 mol%. When combined with other structural units, it is preferably 20 to 95 mol%, more preferably 40 to 90 mol%, even more preferably 50 to 85 mol%, based on the total of all structural units constituting the component (X′1) 60 to 80 mol% is particularly preferable. By setting it as the said range, melt | dissolution contrast becomes favorable.

  In addition to the structural unit (x1), the component (X′1) preferably further has a structural unit represented by the following general formula (x14).

［式中、Ｒ^０は、アルキル基、アリール基、アリールアルキル基である。］

[Wherein, R ⁰ represents an alkyl group, an aryl group, or an arylalkyl group. ]

In formula (x1-14), examples of the alkyl group, aryl group, or arylalkyl group for R ² include the same groups as those described above for R ¹ in formula (x1-11).
The hydrogen atom in the alkyl group, aryl group or aralkyl group in R ⁰ is an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a thiol group (—SH), an alkylthio group (—S—R [R is an alkyl group ]), Oxygen atom (═O), ester group (—C (═O) —O—R [R is an alkyl group]), cyano group, amino group, amide group, carboxy group, — SO ₃ R ¹⁰¹ [R ¹⁰¹ is an alkyl group. _{^{], - (O-R 103}} ) c -OR 102 [R 102 is an alkyl ^{group, R 103} is an alkylene radical, c is an integer of 1 to 10. ] May be substituted. In the alkyl group, aryl group or aralkyl group, the number of hydroxyl groups substituted with these groups is preferably 0 to 3, more preferably 0 to 2, and most preferably 0 or 1.

In the component (X′1), as the structural unit (x14), one type may be used alone, or two or more types may be used in combination.
In the component (X′1), as the structural unit (x14), from the viewpoint of synthesis, it is preferable that R ⁰ in the formula (x1-14) is an aryl group or an aralkyl group. Those which are groups are particularly preferred.
In addition, from the viewpoint of excellent balance between the etching resistance of the coating film and the dimensional controllability during etching, it is preferable that R ⁰ in the formula (x1-14) is an alkyl group, particularly a methyl group. An ethyl group is preferred.
In the component (X′1), the proportion of the structural unit (x14) is preferably 5 to 80 mol%, more preferably 10 to 60 mol%, based on the total of all the structural units constituting the (X′1) component. More preferably, it is 15-50 mol%. By setting it as the above range or more, the balance with other structural units becomes good.

  The component (X′1) may have a structural unit other than the structural units (x11) and (x14). Examples of the other structural units include structural units (x12) and (x13) described later. In addition, it can be appropriately selected from those conventionally proposed as a structural unit in a siloxane resin (hereinafter referred to as a structural unit (x15)).

In the present invention, the component (X′1) is preferably a copolymer having the structural units (x11) and (x14), and more preferably a copolymer composed of the structural units (x11) and (x14).
As the component (X′1), in particular, a copolymer having two structural units represented by the following general formula (X′-11), and two structural units represented by the following general formula (X′-12) The copolymer etc. which have are preferable.

［式中、ｘ、ｙはそれぞれ独立に０〜５の整数であり、Ｒ^１０２はアルキル基である。］

[Wherein, x and y are each independently an integer of 0 to 5, and R ¹⁰² is an alkyl group. ]

[(X′2) component]
As the component (X′2), those having an epoxy group-containing group and / or an ethylenically unsaturated double bond-containing group in the side chain are preferable.
In this case, the development soluble group combined with the epoxy group-containing group and / or the ethylenically unsaturated double bond-containing group is not particularly limited, and development solubility such as a hydrogen atom (Si-H) directly bonded to a silicon atom is possible. A group may be used, and a development-soluble / acid-crosslinking group such as a phenolic hydroxyl group or an alcoholic hydroxyl group may be used. In the present invention, it is particularly preferable that the silicone resin has a hydrogen atom directly bonded to a silicon atom as a development soluble group.
The component (X′2) may optionally further have a development-soluble / acid-crosslinking group.

Preferable (X′2) component includes those having the structural unit (x2) shown below.
In this case, it is preferable that the component (X′2) further has a structural unit (x3) described later.

-Structural unit (x2):
The structural unit (x2) is a structural unit represented by the following formula (x1-12).

［式中、Ｒ^２は、置換基としてエポキシ基含有基および／またはエチレン性不飽和二重結合含有基を有するアルキル基、アリール基またはアラルキル基である。］

[Wherein, R ² is an alkyl group, aryl group or aralkyl group having an epoxy group-containing group and / or an ethylenically unsaturated double bond-containing group as a substituent. ]

In formula (x1-12), the alkyl group, aryl group or aralkyl group in R ² "has an epoxy group-containing group and / or an ethylenically unsaturated double bond-containing group as a substituent" means the alkyl group, It means that the hydrogen atom in the aryl group or arylalkyl group is substituted with an epoxy group-containing group and / or an ethylenically unsaturated double bond-containing group.
The number of acid crosslinking groups having no development solubility in R ² is preferably 1 to 3, more preferably 1 to 2, and most preferably 1.

In formula (x1-12), examples of the alkyl group, aryl group, or arylalkyl group for R ² include the same groups as those described above for R ¹ in formula (x1-11).
The alkyl group, aryl group or arylalkyl group in R ² may have a substituent other than the epoxy group-containing group and / or the ethylenically unsaturated double bond-containing group. Examples of the other substituents include those similar to those exemplified as other substituents which the alkyl group, aryl group or arylalkyl group in R ¹ may have in the description of R ¹ above. .

R ² is preferably an alkyl group having an epoxy group-containing group or an ethylenically unsaturated double bond-containing group from the viewpoint of excellent control of the coating pattern size, etching resistance, and the like. A linear alkyl group having a heavy bond-containing group is particularly preferred.

In the component (X′2), as the structural unit (x12), one type may be used alone, or two or more types may be used in combination.
In the component (X′2), the proportion of the structural unit (x12) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, based on the total of all the structural units constituting the (X′2) component. 15 to 45 mol% is more preferable. When it is at least the lower limit value, the curability is good, and when it is at most the upper limit value, the development solubility is good.

-Structural unit (x3):
The structural unit (x3) is a structural unit represented by the following formula (x1-13).

  In the component (X′2), the proportion of the structural unit (x13) is preferably 20 to 95 mol%, more preferably 35 to 90 mol%, based on the total of all the structural units constituting the (X′2) component. More preferably, it is 45-85 mol%. Etching resistance, development solubility and the like can be improved.

In addition to the structural units (x12) and (x13), the component (X′2) preferably further includes the structural unit (x14) described above. Thereby, the solubility to an organic solvent improves.
In the component (X′2), as the structural unit (x14), it is preferable that R ⁰ in the formula (x1-14) is an alkyl group having the substituent, and in particular, the substituent is — What is (O-R ¹⁰³ ) _c -OR ¹⁰² is preferable.
In the component (X′2), as the structural unit (x14), one type may be used alone, or two or more types may be used in combination.
In the component (X′2), the proportion of the structural unit (x14) is preferably 1 to 20 mol% and more preferably 2 to 15 mol% with respect to the total of all the structural units constituting the component (X′2). 5-10 mol% is more preferable. By setting it to the lower limit value or more, the solubility of the organic solvent is improved, and by setting it to the upper limit value or less, a balance with other structural units can be achieved.

  The component (X′2) may optionally have a structural unit other than the structural units (x12), (x13), and (a14). Examples of the other structural units include the structural units (a11) and (x15) described above.

In the present invention, the component (X′2) is preferably a copolymer having the structural units (x12) and (x13), and the copolymer having the structural units (x12), (x13) and (x14). It is more preferable that Examples of such a copolymer include a copolymer composed of the structural units (x12) and (x13), a copolymer composed of the structural units (x12), (x13), and (x14).
As the component (X′1), in particular, a copolymer having three structural units represented by the following general formula (X′-21), and three structures represented by the following general formula (X′-22) A copolymer having a unit is preferred.

［式中、Ｒ^１０２、ｃおよびＲ^１０３はそれぞれ前記と同じであり、ｖおよびｗはそれぞれ独立に１〜５の整数であり、Ｒ^Ｘはエポキシ基含有基または−Ｏ−Ｃ（＝Ｏ）−Ｃ（Ｒ^１０５）＝ＣＨ_２であり、Ｒ^１０５は水素原子またはメチル基である。］

[Wherein, R ¹⁰² , c and R ¹⁰³ are the same as defined above, v and w are each independently an integer of 1 to 5, and R ^X is an epoxy group-containing group or —O—C (═O) —C (R ¹⁰⁵ ) ═CH ₂ , and R ¹⁰⁵ is a hydrogen atom or a methyl group. ]

  In the formulas (X′-21) and (X′-22), the epoxy-containing group is preferably a group represented by the above formulas (e1) to (e4), and particularly a group represented by (e1). Is preferred.

In the present invention, the component (X ′) preferably has a silicon content of 5% by mass or more, and the upper limit is not particularly limited, but is preferably 50% by mass or less. More preferably, it is 10-48 mass%, It is further more preferable that it is 15-45 mass%, It is especially preferable that it is 20-40 mass%. By being above the lower limit, high resistance to etching such as oxygen plasma etching can be obtained, and the etching selectivity with respect to the resist pattern or the like is sufficient.
The silicon content is a ratio (%) of the total mass of silicon atoms contained in the structural unit constituting the component (X ′) to the total mass of atoms in the structural unit constituting the component (X ′). . The silicon content can be obtained by calculation. For example, in the case of a siloxane polymer composed of a structural unit represented by-[Si (H) O _3/2 ]-, {(28 × 1) × 100} ÷ [{(28 × 1) + (16 × 1.5) + (1 × 1)} × 100] = 52.83%,
_{- [Si (H) O 3/2} ] - a structural unit 30 mol% represented _{by, - [Si (CH 3)} O 3/2] - siloxane polymer comprising the constituent units 70 mole% represented In the case of {(28 × 1) × 100} ÷ <[{(28 × 1) + (16 × 1.5) + (1 × 1)} × 30] + [{(28 × 1) + ( 16 × 1.5) + (12 × 1) + (1 × 3)} × 70]> = 44.6%.
The silicon content can be adjusted by changing each constituent unit or composition ratio.

The mass average molecular weight (Mw) of the component (X ′) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but is preferably 500 to 500,000, more preferably 1000 to 250,000. By setting it in the above range, good coatability can be obtained.
The dispersity (Mw / Mn (number average molecular weight)) of the component (X ′) is preferably 1 to 10, and more preferably 1 to 5.0.
The component (X ′) can be produced using a known method such as JP 2008-525824 A.

[(S ′) component]
The component (S ′) is an organic solvent that dissolves the component (X ′).
As the component (S ′), any component that can dissolve the component (X ′) may be used, and examples thereof include those similar to those exemplified in the description of the component (S) of the positive resist composition.
Considering that the resist coating film forming material is applied onto the resist pattern, the component (S ′) includes an organic solvent that does not dissolve the resist pattern (hereinafter, referred to as a component (S1 ′)). Is preferred. As a result, when the resist coating film forming material is applied onto the support on which the resist pattern is formed, the resist pattern shape can be kept good and the coating pattern can be stably formed.
Here, whether or not the organic solvent to be used is “does not dissolve the resist pattern” can be determined by the following method.
A resist composition is applied on a support and dried to form a resist film having a thickness of 0.2 μm under a condition of 23 ° C., which is immersed in the organic solvent. At this time, even after 60 minutes from the start of immersion, the resist film disappears or the film thickness does not change significantly (preferably the film thickness of the resist film is not less than 0.16 μm). Is not dissolved ".

Specific examples of the component (S1 ′) include alcohol solvents, fluorine solvents, ether organic solvents having no hydroxyl group, and the like.
Here, the “alcohol solvent” is a compound in which at least one of hydrogen atoms of an aliphatic hydrocarbon is substituted with a hydroxyl group, and is a compound that is liquid at normal temperature and normal pressure.
The “fluorinated solvent” is a compound containing a fluorine atom and is a liquid at normal temperature and normal pressure.
The “ether-based organic solvent having no hydroxyl group” is a compound that has an ether bond (C—O—C) in its structure, does not have a hydroxyl group, and is liquid at normal temperature and pressure. The ether organic solvent having no hydroxyl group preferably further has no carbonyl group in addition to the hydroxyl group.

As the alcohol solvent, a monohydric alcohol is more preferable. Among them, although depending on the number of carbons, a primary or secondary monohydric alcohol is preferable, and a primary monohydric alcohol is most preferable.
Here, the monohydric alcohol means a case where the number of hydroxy groups contained in the alcohol molecule is 1, and does not include a dihydric alcohol, a trihydric alcohol, or a derivative thereof.
The boiling point of the alcohol solvent is preferably 80 to 160 ° C., more preferably 90 to 150 ° C., and preferably 100 to 135 ° C., coating properties, stability of composition during storage, and PAB process, Most preferable from the viewpoint of the heating temperature in the PEB process.
Specific examples of the alcohol solvent include n-pentyl alcohol (boiling point 138.0 ° C.), s-pentyl alcohol (boiling point 119.3 ° C.), t-pentyl alcohol (101.8 ° C.), isopentyl alcohol (boiling point 130). 8 ° C), isobutanol (also called isobutyl alcohol or 2-methyl-1-propanol) (boiling point 107.9 ° C), isopropyl alcohol (boiling point 82.3 ° C), 2-ethylbutanol (boiling point 147 ° C), neo Pentyl alcohol (boiling point 114 ° C), n-butanol (boiling point 117.7 ° C), s-butanol (boiling point 99.5 ° C), t-butanol (boiling point 82.5 ° C), 1-propanol (boiling point 97.2 ° C) ), N-hexanol (boiling point 157.1 ° C.), 2-heptanol (boiling point 160.4 ° C.), 3-heptanol (boiling point 1) 6.2 ° C), 2-methyl-1-butanol (boiling point 128.0 ° C), 2-methyl-2-butanol (boiling point 112.0 ° C), 4-methyl-2-pentanol (boiling point 131.8 ° C) ) And the like. In particular, isobutanol (2-methyl-1-propanol), 4-methyl-2-pentanol, n-butanol, and the like are preferable because the effect of containing the component (S1 ′) is good. Among these, isobutanol and n-butanol are preferable, and isobutanol is most preferable.

  Examples of the fluorine-based solvent include perfluoro-2-butyltetrahydrofuran.

Preferred examples of the ether organic solvent having no hydroxyl group include compounds represented by the following general formula (s1′-1).
R ⁴⁰ —O—R ⁴¹ (s1′-1)
[Wherein, R ⁴⁰ and R ⁴¹ each independently represent a hydrocarbon group. Alternatively, R ⁴⁰ and R ⁴¹ may be bonded to form a ring. -O- represents an ether bond. ]

In the above formula, examples of the hydrocarbon group for R ⁴⁰ and R ⁴¹ include an alkyl group and an aryl group, and an alkyl group is preferred. Among ^them, it is preferable that any of R ^{40, R 41} is an alkyl ^group, more preferably a ^{R 40} and ^{R 41} are the same alkyl group.
As each of the alkyl groups of R ^40, R ^41, not particularly limited, for example, straight, branched or cyclic alkyl group, and the like. In the alkyl group, part or all of the hydrogen atoms may or may not be substituted with a halogen atom or the like.
The alkyl group preferably has 1 to 15 carbon atoms, and more preferably 1 to 10 carbon atoms because the coating properties of the negative resist composition are good. Specific examples include an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, an isopentyl group, a cyclopentyl group, and a hexyl group, and an n-butyl group and an isopentyl group are particularly preferable. .
The halogen atom that may be substituted for the hydrogen atom of the alkyl group is preferably a fluorine atom.
Each aryl group for R ⁴⁰ and R ⁴¹ is not particularly limited, and is, for example, an aryl group having 6 to 12 carbon atoms, in which part or all of the hydrogen atoms are alkyl groups, alkoxy groups, It may or may not be substituted with a halogen atom or the like.
The aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specifically, a phenyl group, a benzyl group, a naphthyl group, etc. are mentioned, for example.
The alkyl group that may be substituted for the hydrogen atom of the aryl group is preferably an alkyl group having 1 to 5 carbon atoms, and is a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Is more preferable.
As the alkoxy group which may substitute the hydrogen atom of the said aryl group, a C1-C5 alkoxy group is preferable and a methoxy group and an ethoxy group are more preferable.
The halogen atom that may be substituted for the hydrogen atom of the aryl group is preferably a fluorine atom.
In the above formula, R ⁴⁰ and R ⁴¹ may combine to form a ring.
R ⁴⁰ and R ⁴¹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 10 carbon atoms), and the end of R ⁴⁰ is bonded to the end of R ^41. To form a ring. In addition, the carbon atom of the alkylene group may be substituted with an oxygen atom.
Specific examples of the ether organic solvent include 1,8-cineol, tetrahydrofuran, dioxane and the like.

The boiling point (under normal pressure) of the ether-based organic solvent having no hydroxyl group is preferably 30 to 300 ° C, more preferably 100 to 200 ° C, and further preferably 140 to 180 ° C. By being equal to or higher than the lower limit of the temperature range, the component (S ′) is difficult to evaporate during spin coating during application of the negative resist composition, so that coating unevenness is suppressed and coating properties are improved. On the other hand, by being below the upper limit, the (S ′) component is sufficiently removed from the resist film by pre-baking, and the formability of the second resist film is improved. Moreover, when the temperature is within this range, the effect of reducing the film thickness of the resist pattern and the stability of the composition during storage are further improved. Moreover, it is preferable also from a viewpoint of the heating temperature of a PAB process or a PEB process.
Specific examples of ether organic solvents having no hydroxyl group include, for example, 1,8-cineol (boiling point 176 ° C.), dibutyl ether (boiling point 142 ° C.), diisopentyl ether (boiling point 171 ° C.), dioxane (boiling point 101 ° C.). ), Anisole (boiling point 155 ° C.), ethyl benzyl ether (boiling point 189 ° C.), diphenyl ether (boiling point 259 ° C.), dibenzyl ether (boiling point 297 ° C.), phenetole (boiling point 170 ° C.), butyl phenyl ether, tetrahydrofuran (boiling point 66 ° C.) ), Ethyl propyl ether (boiling point 63 ° C.), diisopropyl ether (boiling point 69 ° C.), dihexyl ether (boiling point 226 ° C.), dipropyl ether (boiling point 91 ° C.) and the like.
The ether-based organic solvent having no hydroxyl group is preferably a cyclic or chain-shaped ether-based organic solvent because it has a good effect of reducing the film loss of the resist pattern. Among them, 1,8-cineole, dibutyl ether is preferable. And at least one selected from the group consisting of diisopentyl ether is preferred.

Any one of these (S1 ′) components may be used alone, or two or more thereof may be mixed and used.
As the component (S1 ′), an alcohol solvent is preferably used from the viewpoint of applicability and the solubility of materials such as the component (X ′).

When the component (S1 ′) is included as the component (S ′), the component (S ′) is an organic solvent other than the component (S1 ′) (hereinafter referred to as (S2 ′)) as long as the effects of the present invention are not impaired. May be included). As the component (S2 ′), any component that can dissolve each component to be used may be used, and examples thereof include those similar to those exemplified as the component (S) in the resist composition.
However, in order to sufficiently obtain the effect of including the (S1 ′) component, the ratio of the (S1 ′) component in the (S ′) component is 50 to 100 with respect to the total mass of the (S ′) component. % By mass is preferable, 80 to 100% by mass is more preferable, and 100% by mass is most preferable. That is, the (S ′) component is most preferably composed of only the (S1 ′) component.

  The amount of the (S ′) component used in the resist coating film forming material is not particularly limited, and may be set as appropriate so that the resist coating film forming material becomes a liquid that can be applied onto the support.

[Crosslinking agent]
It is preferable that the resist coating film forming material further contains a crosslinking agent (hereinafter referred to as (C ′) component) in addition to the above (X ′) component and (S ′) component. Thereby, the crosslinking reaction is promoted, and the uniformity of the film thickness of the resist coating film formed on the resist pattern surface is improved.
In particular, when the acid crosslinking group in the component (X ′) is a phenolic hydroxyl group and / or an alcoholic hydroxyl group or an ethylenically unsaturated double bond-containing group, the component (C ′) is contained. It is preferable.
The component (C ′) is not particularly limited, and can be arbitrarily selected from conventionally known ones, for example, cross-linking agents used in conventionally known chemically amplified negative resist compositions. Can be used.
Specifically, for example, 2,3-dihydroxy-5-hydroxymethylnorbornane, 2-hydroxy-5,6-bis (hydroxymethyl) norbornane, cyclohexanedimethanol, 3,4,8 (or 9) -trihydroxytri Aliphatic cyclic carbonization having a hydroxyl group or a hydroxyalkyl group or both such as cyclodecane, 2-methyl-2-adamantanol, 1,4-dioxane-2,3-diol, 1,3,5-trihydroxycyclohexane Examples thereof include hydrogen and oxygen-containing derivatives thereof.

In addition, amino group-containing compounds such as melamine, acetoguanamine, benzoguanamine, urea, ethylene urea, propylene urea, glycoluril are reacted with formaldehyde or formaldehyde and lower alcohol, and the hydrogen atom of the amino group is hydroxymethyl group or lower alkoxymethyl. And a compound substituted with a group and a compound having an epoxy group.
Of these, those using melamine are melamine-based crosslinking agents, those using urea are urea-based crosslinking agents, those using alkylene ureas such as ethylene urea and propylene urea are alkylene urea-based crosslinking agents, and glycoluril is used. What was used was a glycoluril-based crosslinking agent, and what used an epoxy group-containing compound was called an epoxy-based crosslinking agent.
The crosslinking agent is preferably at least one selected from the group consisting of melamine crosslinking agents, urea crosslinking agents, alkylene urea crosslinking agents, glycoluril crosslinking agents, and epoxy crosslinking agents, and particularly glycoluril. System crosslinking agents are preferred.

  Melamine-based crosslinking agents include compounds in which melamine and formaldehyde are reacted to replace the amino group hydrogen atom with a hydroxymethyl group, and melamine, formaldehyde and lower alcohol are reacted to convert the amino group hydrogen atom into a lower alkoxy group. Examples include compounds substituted with a methyl group. Specific examples include hexamethoxymethyl melamine, hexaethoxymethyl melamine, hexapropoxymethyl melamine, hexabutoxybutyl melamine, and the like, among which hexamethoxymethyl melamine is preferable.

  Urea-based crosslinking agents include compounds in which urea and formaldehyde are reacted to replace amino group hydrogen atoms with hydroxymethyl groups, and urea, formaldehyde and lower alcohols are reacted to convert amino group hydrogen atoms into lower alkoxy groups. Examples include compounds substituted with a methyl group. Specific examples include bismethoxymethylurea, bisethoxymethylurea, bispropoxymethylurea, bisbutoxymethylurea, etc. Among them, bismethoxymethylurea is preferable.

  As an alkylene urea type crosslinking agent, the compound represented by the following general formula (C-1) is mentioned.

［式（Ｃ−１）中、Ｒ^５’とＲ^６’はそれぞれ独立に水酸基又は低級アルコキシ基であり、Ｒ^３’とＲ^４’はそれぞれ独立に水素原子、水酸基又は低級アルコキシ基であり、ｖは０又は１〜２の整数である。］

[In the formula (C-1), R ⁵ ′ and R ⁶ ′ are each independently a hydroxyl group or a lower alkoxy group, and R ³ ′ and R ⁴ ′ are each independently a hydrogen atom, a hydroxyl group or a lower alkoxy group, v is 0 or an integer of 1-2. ]

When R ⁵ ′ and R ⁶ ′ are lower alkoxy groups, they are preferably alkoxy groups having 1 to 4 carbon atoms, and may be linear or branched. R ⁵ ′ and R ⁶ ′ may be the same or different from each other. More preferably, they are the same.
When R ³ ′ and R ⁴ ′ are lower alkoxy groups, they are preferably alkoxy groups having 1 to 4 carbon atoms, and may be linear or branched. R ³ ′ and R ⁴ ′ may be the same or different from each other. More preferably, they are the same.
v is 0 or an integer of 1 to 2, and preferably 0 or 1.
As the alkylene urea crosslinking agent, a compound in which v is 0 (ethylene urea crosslinking agent) and / or a compound in which v is 1 (propylene urea crosslinking agent) are particularly preferable.
The compound represented by the general formula (C-1) can be obtained by a condensation reaction of alkylene urea and formalin, and by reacting this product with a lower alcohol.

  Specific examples of the alkylene urea crosslinking agent include, for example, mono and / or dihydroxymethylated ethylene urea, mono and / or dimethoxymethylated ethylene urea, mono and / or diethoxymethylated ethylene urea, mono and / or dipropoxy Ethylene urea-based crosslinking agents such as methylated ethylene urea, mono and / or dibutoxymethylated ethylene urea; mono and / or dihydroxymethylated propylene urea, mono and / or dimethoxymethylated propylene urea, mono and / or diethoxymethyl Propylene urea-based crosslinkers such as propylene urea, mono and / or dipropoxymethylated propylene urea, mono and / or dibutoxymethylated propylene urea; 1,3-di (methoxymethyl) 4,5-dihydroxy-2- Imidazolidinone, 1,3-di (Metoki Like, etc.) -4,5-dimethoxy-2-imidazolidinone.

Examples of the glycoluril-based crosslinking agent include glycoluril derivatives in which the N position is substituted with one or both of a hydroxyalkyl group and an alkoxyalkyl group having 1 to 4 carbon atoms. Such a glycoluril derivative can be obtained by a condensation reaction of glycoluril and formalin and by reacting this product with a lower alcohol.
Specific examples of the glycoluril-based crosslinking agent include, for example, mono, di, tri and / or tetrahydroxymethylated glycoluril; mono, di, tri and / or tetramethoxymethylated glycoluril; mono, di, tri and / or Tetraethoxymethylated glycoluril; mono, di, tri and / or tetrapropoxymethylated glycoluril; mono, di, tri and / or tetrabutoxymethylated glycoluril.

The epoxy-based crosslinking agent is not particularly limited as long as it has an epoxy group, and can be arbitrarily selected and used. Among them, those having two or more epoxy groups are preferable. By having two or more epoxy groups, crosslinking reactivity is improved.
The number of epoxy groups is preferably 2 or more, more preferably 2 to 4, and most preferably 2.
The following are suitable as the epoxy-based crosslinking agent.

These crosslinking agents may be used individually by 1 type, and may be used in combination of 2 or more type.
When a crosslinking agent is blended in the resist coating film forming material, the blending amount of the crosslinking agent is preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the component (X ′), and 1 to 15 Mass parts are more preferable, and 5 to 12 parts by mass are even more preferable. When the content of the crosslinking agent is not less than the lower limit of the above range, the effect of blending the crosslinking agent is sufficiently obtained, and when it is not more than the upper limit, the storage stability of the resist coating film forming material is It is good.

[Other ingredients]
In addition to the above components, the resist coating film forming material may contain additives such as nitrogen-containing organic compounds, antifoaming agents, surfactants, sensitizers, and stabilizers as necessary. .
Among these, it is preferable to contain a nitrogen-containing organic compound (hereinafter referred to as (D ′) component). Thereby, excessive diffusion of the acid generated in the resist pattern in the resist coating film can be suppressed, and the contrast margin is improved.
The component (D ′) may be any component as long as it can capture the acid generated in the resist pattern, and examples thereof include the same ones listed as the component (D) in the resist composition.
When the component (D ′) is added to the resist coating film forming material, the amount of the component (D ′) is 0.01 to 10 parts by mass with respect to 100 parts by mass of the component (X ′). Is preferable, and 0.1-5 mass parts is more preferable.

A conventionally well-known thing can be utilized as an antifoamer, for example, a silicone type compound, a fluorine-type compound, etc. are mentioned.
As the surfactant, conventionally known ones such as an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant can be used.

  The resist coating film forming material can be prepared, for example, by mixing the above-described components with a stirrer and, if necessary, filtering with a filter such as a 5 μm membrane filter.

≪Pattern formation method≫
The pattern forming method of the present invention includes a step of etching the support on which the coating pattern is formed by the above-described coating pattern forming method of the present invention.
In this pattern forming method, a pattern can be formed on a support by a spacer technique using the above-described coating pattern. For example, after a line-shaped coating pattern is formed on a support, the coating film on the upper surface of the coating pattern is removed to expose the resist pattern, and the resist pattern is removed by etching. The coating on both sides of the pattern will remain. That is, a higher-density pattern twice as many as the initial resist pattern is formed on the support.
Hereinafter, preferred embodiments of the pattern forming method of the present invention will be described with reference to the drawings.

FIG. 3 is a schematic process diagram showing the first embodiment of the pattern forming method of the present invention.
In the present embodiment, a process of forming a coating pattern consisting of a resist pattern 13 whose surface is coated with a resist coating film 14 on the support 10 by the coating pattern forming method of the present invention (coating pattern forming process); And a step of removing the upper part of the covering pattern to expose the resist pattern 13 (resist pattern exposure step), and a step of performing an etching process from above the support 10 (etching step).
Hereinafter, each process will be described in more detail.

(Coating pattern forming process)
In the coating pattern forming step, first, a support 10 in which an organic film 12 is formed on a substrate 11 is prepared, and the support 10 is coated using the coating pattern forming method of the present invention. Form a pattern.
That is, first, by performing step (i) of the coating pattern forming method of the present invention, as shown in FIG. 3A, a line-like shape having a width w and a height h is formed on the surface 12a of the organic film 12. A line-and-space pattern in which the resist pattern 13 is arranged with a predetermined interval s is formed.
Next, by performing steps (ii) to (iv) of the coating pattern forming method of the present invention, as shown in FIG. 3B, a resist coating film 14 that covers the surface of the resist pattern 13 is formed. A coating pattern is obtained.

(Resist pattern exposure process)
In the resist pattern exposure step, the resist pattern 13 is exposed as shown in FIG. 3C by removing the upper portion of the coating pattern so that at least the resist coating film 14 on the upper surface of the resist pattern 13 is removed. .
As a result, the resist pattern 13 and the resist coating film (resist coating film formed on the side surface of the resist pattern 13; hereinafter referred to as a side surface portion) 14A that remains without being removed on the support 10 are obtained. Will exist.
The method for removing the upper portion of the coating pattern is not particularly limited, and may be performed by, for example, etching (etchback), or a known smoothing method may be used. Examples of the smoothing method include chemical mechanical polishing (CMP).

In the resist pattern exposure step, the upper portion of the coating pattern is preferably removed by etch back.
The etch back is preferably performed by dry etching from the viewpoint of simplicity of the processing step.
Known dry etching methods include chemical etching such as downflow etching and chemical dry etching; physical etching such as sputter etching and ion beam etching; and chemical and physical etching such as RIE (reactive ion etching). This method can be used.
The most common dry etching is parallel plate RIE. In this method, first, a multilayer laminate is put into a chamber of an RIE apparatus, and a necessary etching gas is introduced. When a high-frequency voltage is applied to the holder of the multilayer stack placed in parallel with the upper electrode in the chamber, the etching gas is turned into plasma. In the plasma, there are charged particles such as positive and negative ions and electrons, and etching species such as neutral active species. When these etching species are adsorbed on the lower resist layer, a chemical reaction occurs, the reaction product is detached from the surface and exhausted to the outside, and etching proceeds.
As an etching gas used for etch back, a halogen-based gas is preferable. Examples of the halogen-based gas include hydrocarbon gases in which some or all of the hydrogen atoms are substituted with halogen atoms such as fluorine atoms and chlorine atoms. Specifically, fluorocarbon gases and carbon chloride gases are used. Etc. Examples of the fluorocarbon gas include a CF gas such as tetrafluoromethane (CF ₄ ) gas, a CHF gas such as trifluoromethane (CHF ₃ ) gas, and the like. Examples of the carbon chloride-based gas include tetrachloromethane (CCl ₄ ) gas. Any one of these etching gases may be used alone, or two or more thereof may be mixed and used. Further, nitrogen gas, rare gas (argon gas, etc.), etc. may be mixed with the etching gas.
As an etching gas used for the etch back, a fluorocarbon gas is preferable, and CF ₄ gas and / or CHF ₃ gas is particularly preferable.

(Etching process)
In the present embodiment, the etching process is performed until the surface 11a of the substrate 11 is exposed under the condition that the side surface portion 14A serves as an etching mask and the material that forms the resist pattern 13 and the organic film 12 is removed.
Thereby, the resist pattern 13 is removed, and portions of the organic film 12 other than the portion below the side surface portion 14A are removed. As a result, as shown in FIG. 3D, a pattern 15 including the organic film 12 (organic pattern 12A) remaining without being removed and the side surface portion 14A stacked thereon is formed on the substrate 11. .
Etching in this step is preferably performed by dry etching. As a dry etching method, a known method similar to the above can be used.
The type of etching gas used at this time may be any as long as the etching selectivity can be obtained between the side surface portion 14A serving as an etching mask and the resist pattern 3. For example, oxygen (O ₂ ) gas, sulfur dioxide gas, and the like described above. And halogen-based gases. Any one of these etching gases may be used alone, or two or more thereof may be mixed and used. Further, nitrogen gas, rare gas (argon gas, etc.), etc. may be mixed with the etching gas.
As the etching method in this step, oxygen plasma etching (dry etching using plasma obtained from O ₂ gas) is particularly preferable because the etching selectivity with respect to the side surface portion 14A is high.
After the etching, a step of removing the residue or cleaning the substrate 11 having the pattern 15 can be performed as necessary.

As described above, twice as many patterns 15 as the first resist pattern 13 are formed on the substrate 11.
The pattern 15 can be used for various purposes. For example, it can be used as it is as a structure (for example, a circuit) on the substrate 11 or as a mask for transferring the same pattern as the pattern 15 to the substrate 11.
Moreover, as shown in FIG.3 (e), 14 A of side parts may be removed and the organic pattern 12A may be exposed. Thereby, twice as many organic patterns as the first resist pattern 13 can be formed on the substrate.
Similar to the pattern 15, the organic pattern can be used for various purposes. For example, a semiconductor device or the like can be manufactured by etching the substrate 11 using the organic pattern as a mask.

According to the pattern forming method of the present invention, for example, a pattern having a linear density (number per unit length) twice that of the resist pattern originally formed on the support can be formed.
For example, when a line-and-space pattern is formed as a resist pattern as shown in the above embodiment, a narrow pitch is formed by a simple operation of etching a support on which a coating pattern obtained from the resist pattern is formed. A dense line and space pattern can be formed. Specifically, for example, in the embodiment shown in FIG. 3, the ratio of the line width w in the line-and-space pattern and the spacing (space width) s between the patterns is set to line width: space width = 1: 3, and the resist When the film thickness of the coating film 14 is the same as that of the line w, finally, the line-shaped pattern 15 having the line width w is formed on the substrate 11 with an initial interval of 1/3 (line width: space width = 1: 1).
In addition, the pattern forming method of the present invention can easily form a fine and high-density pattern as described above with a small number of steps, via the coating pattern forming step by the coating pattern forming method of the present invention, The shape of the formed pattern is also good.
For example, in the conventional spacer patterning method, it is necessary to perform the etching process a plurality of times, which is troublesome. On the other hand, in the present invention, for example, the process up to the formation of the coating pattern can be advanced using only a general exposure apparatus, and thereafter, pattern formation by etching can be advanced collectively by the etching apparatus. Therefore, it is possible to reduce the movement of the support between the plurality of apparatuses, for example, between the exposure apparatus and the etching apparatus, and the trouble associated therewith.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.
[Preparation of resist composition]
Each component shown in Table 1 was mixed and dissolved to prepare a resist composition (positive type).

Each abbreviation in Table 1 has the following meaning. Moreover, the numerical value in [] of Table 1 is a compounding quantity (mass part).
(A) -1: a copolymer having a mass average molecular weight (Mw) of 7000 and a dispersity of 1.4 represented by the following chemical formula (A) -1. In the formula, the symbol on the lower right of () indicates the proportion (mol%) of the structural unit to which the symbol is attached, and a1 / a2 / a3 = 30/50/20.
(B) -1: Di (1-naphthyl) phenylsulfonium nonafluoro-n-butanesulfonate.
(B) -2: Compound (B) -2 represented by the following formula (B) -2.
(D) -1: Triethylamine.
(E) -1: salicylic acid.
(S) -1: γ-butyrolactone.
(S) -2: Mixed solvent of PGMEA / PGME = 6/4 (mass ratio).
(F) -1: a polymer compound represented by the following formula (F) -1 (Mw = 8000, Mw / Mn = 1.5).

[Preparation of resist coating film forming material]
Each component shown in Table 2 was mixed and dissolved to prepare a resist coating film forming material.

Each abbreviation in Table 2 has the following meaning. Moreover, the numerical value in [] of Table 2 is a compounding quantity (mass part).
(X ′)-1: a copolymer represented by the following chemical formula (X ′)-1 [1 / m / n = 60/30/10 (molar ratio)] (manufactured by Dow Corning, Mw = 10000, Mw /Mn=4.5, silicon content: 23%).
(X ′)-2: a copolymer represented by the following chemical formula (X ′)-2 [m / n = 70/30 (molar ratio)] (manufactured by Toray Fine Co., Ltd., Mw = 10000, Mw / Mn = 1) .2, silicon content: 19%).
(X ′)-3: a copolymer represented by the following chemical formula (X ′)-3 (manufactured by Dow Corning, Mw = 16000, Mw / Mn = 2.70, silicon content: 40%).
(C ′)-1: a compound represented by the following chemical formula (C ′)-1.
(C ′)-2: A compound represented by the following chemical formula (C ′)-2.
(S ′)-1: Isobutanol.

[Examples 1 and 2 and Comparative Example 1 (resist composition 1 / resist coating film forming materials 1, 3, 4; 120 nm L / S)]
(I)
An organic antireflection film composition “ARC-29A” (trade name, manufactured by Brewer Science) is applied onto a substrate (8-inch silicon wafer) using a spinner, and baked on a hot plate at 205 ° C. for 60 seconds. Then, an organic antireflection film having a film thickness of 82 nm was formed by drying.
The resist composition 1 is applied onto the organic antireflection film using a spinner, prebaked (PAB) at 120 ° C. for 60 seconds on a hot plate, and dried to obtain a film thickness of 100 nm. The resist film was formed.
Next, an ArF exposure apparatus NSR-S302A (Nikon Corp .; NA (numerical aperture) = 0.60, 2/3 annular illumination) is applied to the resist film through a mask (6% halftone) pattern. Then, ArF excimer laser (193 nm) was selectively irradiated. Next, post-exposure heating (PEB) treatment was performed at 110 ° C. for 60 seconds, and a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution “NMD-3” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23 ° C. ) For 30 seconds. Thereafter, the substrate was rinsed with pure water for 30 seconds and post-baked at 100 ° C. for 60 seconds.
As a result, a line-and-space resist pattern (hereinafter referred to as a 120 nm L / S pattern) in which line patterns with a line width of 120 nm were arranged at equal intervals (pitch 480 nm) was formed on the organic antireflection film.

(Ii)
On the organic antireflection film on which the 120 nm L / S pattern is formed, the resist coating film forming materials 1, 3, and 4 are respectively applied using a spinner, and then heated on a hot plate at 90 ° C. for 90 seconds. A pre-baking process (PAB) was performed under the conditions and dried to form a coating film having a thickness of about 120 nm.

(Iii)
Next, the entire surface of the resist film was exposed at an exposure amount of 24.5 mJ / cm ² using an ArF exposure apparatus NSR-S302A (Nikon Corporation; NA (numerical aperture) = 0.60, 2/3 annular illumination). Exposure (exposure not through a mask pattern) was performed, and then a baking process was performed for 60 seconds at a predetermined baking temperature (125 ° C., 130 ° C.).

(Iv)
Next, development processing was performed at 23 ° C. for 30 seconds using a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution as a developer. Thereafter, the substrate was rinsed with pure water for 30 seconds and post-baked at 100 ° C. for 60 seconds.

After the post-baking, the cross section of the pattern of the obtained support surface was observed with an SEM (scanning electron microscope), and the width (line width) and height were 120 nmL / before coating the resist coating film forming material. Compared with the S pattern (uncoated pattern), the amount of dimensional change was determined. The results are shown in Table 3. The dimensional change amount on the side surface of the line indicates the value of the total change amount (the value on one side of the line was about ½ of the value).
As a result, when the resist coating film forming materials 1 and 3 are used, the width and height of the line pattern are the same regardless of whether the baking process in (iii) is performed at 125 ° C. or 130 ° C. Each was wider than the line width and height of the pattern before coating. From this, it was confirmed that a coating film was formed on the resist pattern surface and a coating pattern was obtained.
Further, the line width and height were larger as the baking temperature was higher.
In addition, when the resist coating film forming material 4 using a siloxane polymer not containing an acid crosslinking group was used, formation of a coating pattern could not be confirmed.

[Example 3 (resist composition 1 / resist coating film forming material 2; 120 nm L / S)]
A 120 nm L / S pattern was formed in the same manner as in Example 1 (i).
The resist coating film forming material 2 is applied to the organic antireflection film having the 120 nm L / S pattern formed thereon using a spinner, and prebaked on a hot plate at 90 ° C. for 90 seconds ( PAB) was performed and dried to form a coating film having a film thickness of about 120 nm.
Next, with the ArF exposure apparatus NSR-S302A (Nikon Corporation; NA (numerical aperture) = 0.60, 2/3 annular illumination), a predetermined exposure amount is applied to the coating film (and 120 nm L / S pattern). Full surface exposure (exposure not through a mask pattern) was performed at (24.0 mJ / cm ² , 24.5 mJ / cm ² ), and then a baking process was performed at 135 ° C. for 60 seconds.
Next, development, water rinsing, and post-baking steps were performed under the same conditions as in (iv) of Example 1 above.
After the post-baking, the cross section of the pattern of the obtained support surface was observed with an SEM (scanning electron microscope), and the width (line width) and height were 120 nmL / before coating the resist coating film forming material. Compared with the S pattern (uncoated pattern), the amount of dimensional change was determined. The results are shown in Table 4.

As shown in the above results, the width and height of the line pattern both when the exposure treatment for the coating film (and the L / S pattern) was performed at 24.0 mJ / cm ² and when performed at 24.5 mJ / cm ^2. However, it was larger than the line width of the pattern before coating. From this, it was confirmed that a coating film was formed on the resist pattern surface and a coating pattern was obtained.
Further, the line width and height were increased as the exposure amount was increased.

[Example 4 (resist composition 2 / resist coating film forming material 2, 60 nm L / S)]
(I)
An organic antireflective coating composition “ARC-29A” (trade name, manufactured by Brewer Science) is applied onto a substrate (12-inch silicon wafer) using a spinner and baked on a hot plate at 205 ° C. for 60 seconds. Then, an organic antireflection film with a film thickness of 85 nm was formed by drying.
The resist composition 2 is applied onto the organic antireflection film using a spinner, prebaked (PAB) at 120 ° C. for 60 seconds on a hot plate, and dried to obtain a film thickness of 100 nm. The resist film was formed.
Next, an ArF exposure apparatus NSR-S308F (Nikon Corp .; NA (numerical aperture) = 0.92, σ = Crossole (0.57 / 0.72)) is applied to the resist film through a mask pattern. Then, ArF excimer laser (193 nm) was selectively irradiated. Next, post-exposure heating (PEB) treatment was performed at 110 ° C. for 60 seconds, and a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution “NMD-3” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23 ° C. ) For 30 seconds. Thereafter, the substrate was rinsed with pure water for 30 seconds and post-baked at 100 ° C. for 60 seconds.
As a result, a line-and-space resist pattern (hereinafter referred to as a 65 nm L / S pattern) in which line patterns with a line width of 65 nm were arranged at equal intervals (pitch: 200 nm) was formed on the organic antireflection film.

The resist coating film forming material 2 is applied on the organic antireflection film having the 65 nm L / S pattern formed thereon using a spinner, and prebaked on a hot plate at 90 ° C. for 90 seconds ( PAB) was performed and dried to form a coating film having a film thickness of about 135 nm.
Next, the coating film (and 65 nm L / S pattern) was applied with an ArF exposure apparatus NSR-S308F (manufactured by Nikon Corporation; NA (numerical aperture) = 0.92, σ = Crossole (0.57 / 0.72)). On the other hand, the whole surface exposure (exposure not through a mask pattern) is performed at a predetermined exposure amount (25.0 mJ / cm ² , 25.5 mJ / cm ² , 26.0 mJ / cm ² ), and then at 135 ° C. for 60 seconds. Was baked.
Next, development processing was performed at 23 ° C. for 30 seconds using a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution as a developer. Thereafter, the substrate was rinsed with pure water for 30 seconds and post-baked at 100 ° C. for 60 seconds.
After the post-baking, the cross section of the pattern of the obtained support surface was observed with an SEM (scanning electron microscope), and the width (line width) and height were 65 nmL / height before application of the resist coating film forming material. Compared with the S pattern (uncoated pattern), the amount of dimensional change was determined. The results are shown in Table 5.

As shown in the results, even when subjected to exposure processing for the coating (and 65nmL / S pattern) with 25.0mJ / cm ^2, even if made in 25.5mJ / cm ^2, at 26.0mJ / cm ² Also when it performed, the width | variety and height of the line pattern were large compared with the line width of the pattern before application | coating. From this, it was confirmed that a coating film was formed on the resist pattern surface and a coating pattern was obtained.

[Example 5 (Etching for coating pattern)]
In Example 4, the following process was performed on the coating pattern formed by performing the exposure process on the coating film (and the 65 nm L / S pattern) at 26.0 mJ / cm ² .
The substrate on which the coating pattern was formed was mixed with CF ₄ gas, Ar gas and N ₂ gas (flow rate ratio: CF ₄ / Ar /) using a plasma etching apparatus (manufactured by Tokyo Electron, apparatus name: Telius). Etching treatment (pressure: 4 Pa; RF power source (upper electrode / lower electrode): 500 W / 1800 W; temperature: 20 ° C .; treatment time: 6 seconds) by N ₂ = 9/57/34).

The substrate after the etching treatment was mixed with O ₂ gas and N ₂ gas (flow rate ratio: O ₂ / N ₂ = 1/1) using a plasma etching apparatus (manufactured by Tokyo Electron, apparatus name: Telius). Oxygen plasma etching treatment (pressure: 0.67 Pa; RF power source (upper electrode / lower electrode): 750 W / 150 W; temperature: 0 ° C .; treatment time: 10 seconds).

  The top surface and cross section of the substrate after the etching treatment were observed by SEM. As a result, only a line pattern (line pattern derived from the coating film) having a line width of about 19.9 nm remains on the substrate at positions on both sides of the 65 nm L / S pattern. (The 65 nm L / S pattern, the organic antireflection film below it, and the organic antireflection film below the portion where the coating pattern was not formed (space portion)) had disappeared.

  DESCRIPTION OF SYMBOLS 1 ... Support body, 2 ... Resist pattern, 3 ... Coating film, 4 ... Resist coating film, 7 ... Covering pattern, 10 ... Support body, 11 ... Substrate, 12 ... Organic film, 13 ... Resist pattern, 14 ... Resist coating Cover film, 15 ... pattern.

Claims (17)

A coating pattern forming method for forming a pattern having a surface coated with a coating film on a support,
Forming a resist pattern on a support using a resist composition containing an acid generator capable of generating an acid by exposure and / or heat; and
On the support on which the resist pattern is formed, a resist coating film forming material containing a silicon-containing polymer capable of causing a crosslinking reaction by the action of an acid and an organic solvent that dissolves the silicon-containing polymer is applied. Forming a coating film (ii),
Exposing and / or baking the resist pattern to generate an acid in the resist pattern (iii);
A step (iv) of developing the coating film;
Including
The silicon-containing polymer is a silicone resin;
The method for forming a coating pattern, wherein the silicone resin has a phenolic hydroxyl group and / or an alcoholic hydroxyl group in a side chain. A coating pattern forming method for forming a pattern having a surface coated with a coating film on a support,
Forming a resist pattern on a support using a resist composition containing an acid generator capable of generating an acid by exposure and / or heat; and
On the support on which the resist pattern is formed, a resist coating film forming material containing a silicon-containing polymer capable of causing a crosslinking reaction by the action of an acid and an organic solvent that dissolves the silicon-containing polymer is applied. Forming a coating film (ii),
Exposing and / or baking the resist pattern to generate an acid in the resist pattern (iii);
A step (iv) of developing the coating film;
Including
The silicon-containing polymer is a silicone resin;
The method for forming a coating pattern, wherein the silicone resin has an epoxy group-containing group and / or an ethylenically unsaturated double bond-containing group in a side chain and a hydrogen atom directly bonded to a silicon atom. The method for forming a coating pattern according to claim 1 or 2, wherein the silicon-containing polymer has a silicon content of 5 to 50 mass %.   The said silicone resin is a coating pattern formation method of Claim 1 which has an epoxy group containing group and / or an ethylenically unsaturated double bond containing group in a side chain.   The said silicone resin is a coating pattern formation method of Claim 4 which has a hydrogen atom further couple | bonded with the silicon atom directly.   The said resist coating film forming material is a coating pattern formation method as described in any one of Claims 1-5 containing a crosslinking agent.   The said resist coating film forming material is a coating pattern formation method as described in any one of Claims 1-6 which does not contain the said acid generator.   The said organic solvent is an organic solvent which does not melt | dissolve a resist pattern, The coating pattern formation method as described in any one of Claims 1-7.   9. The coating pattern according to claim 8, wherein the organic solvent that does not dissolve the resist pattern is at least one selected from the group consisting of alcohol organic solvents, fluorine organic solvents, and ether organic solvents having no hydroxyl group. Forming method.   The coating pattern formation method as described in any one of Claims 1-9 which performs the said image development process using the organic solvent which melt | dissolves an alkali developing solution and / or the said silicon-containing polymer. Forming a resist pattern on the support using a resist composition containing an acid generator capable of generating an acid by exposure and / or heat; and on the support on which the resist pattern is formed And (ii) forming a coating film by applying a resist coating film forming material containing a silicon-containing polymer capable of causing a crosslinking reaction by the action of an acid and an organic solvent for dissolving the silicon-containing polymer; And a step (iii) of exposing and / or baking the resist pattern to generate an acid in the resist pattern, and a step (iv) of developing the coating film. Is a resist coating film forming material used in a coating pattern forming method for forming a pattern coated with a coating film on a support,
Containing a silicon-containing polymer capable of causing a crosslinking reaction by the action of an acid, and an organic solvent for dissolving the silicon-containing polymer,
The silicon-containing polymer is a silicone resin;
A material for forming a resist coating film, wherein the silicone resin has a phenolic hydroxyl group and / or an alcoholic hydroxyl group in a side chain. The material for forming a resist coating film according to claim 11, wherein the silicon-containing polymer has a silicon content of 5 to 50 mass %. The material for forming a resist coating film according to claim 11 or 12 containing a crosslinking agent. The material for forming a resist coating film according to any one of claims 11 to 13 , which does not contain an acid generator capable of generating an acid by exposure and / or heat. The material for forming a resist coating film according to any one of claims 11 to 14 , wherein the organic solvent is an organic solvent that does not dissolve the resist pattern. 16. The resist coating film forming material according to claim 15 , wherein the organic solvent is at least one selected from the group consisting of an alcohol organic solvent, a fluorine organic solvent, and an ether organic solvent having no hydroxyl group. .   The pattern formation method including the process of performing an etching process with respect to the support body in which the coating pattern was formed by the coating pattern formation method as described in any one of Claims 1-10.

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