JP5518458B2 - Pattern formation method - Google Patents

Description

  In the present invention, after forming the first resist pattern using the first chemically amplified positive resist composition, the second film-forming material is applied thereon to form the second film, The present invention relates to a pattern forming method for forming a pattern in which an image of the first resist pattern is reversed on the second film by performing exposure, post-exposure baking and alkali development.

A technique (pattern formation technique) for forming a fine pattern on a support and etching the lower layer of the pattern by using this as a mask is widely adopted for the creation of IC devices in the semiconductor field. Has attracted attention.
The fine pattern is usually made of an organic material, and is formed by a technique such as a lithography method or a nanoimprint method. For example, in a lithography method, a resist film made of a resist material is formed on a support such as a substrate, and the resist film is subjected to selective exposure with radiation such as light or an electron beam, followed by development processing. Thus, a step of forming a resist pattern having a predetermined shape on the resist film is performed. And a semiconductor element etc. are manufactured through the process of processing a board | substrate by an etching using the said resist pattern as a mask. A resist material in which the solubility of the exposed portion in the developer increases is referred to as a positive type, and a resist material in which the solubility of the exposed portion in the developer decreases is referred to as a negative type.
In recent years, pattern miniaturization is rapidly progressing due to the advancement of lithography technology. As a technique for miniaturizing a resist pattern, the exposure light source is generally shortened in wavelength. Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but now mass production of semiconductor elements using KrF excimer laser or ArF excimer laser has been started. Lithography using an ArF excimer laser enables pattern formation with a resolution of 45 nm level. In addition, in order to further improve the resolution, studies have been made on F ₂ excimer lasers, electron beams, EUV (extreme ultraviolet rays), X-rays, and the like having shorter wavelengths than these excimer lasers.
Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing a pattern with fine dimensions. As a resist material that satisfies such requirements, a chemically amplified resist composition containing an acid generator that generates an acid upon exposure is used. In general, the chemically amplified resist composition is mixed with a base material component whose solubility in an alkaline developer is changed by the action of an acid, together with the acid generator. For example, as a base material component of a positive chemically amplified resist, a material whose solubility in an alkaline developer is increased by the action of an acid is used (for example, see Patent Document 1). Resins are mainly used as the base component of the chemically amplified resist composition.

As one of the methods for further improving the resolution, exposure (immersion exposure) is performed by interposing a liquid (immersion medium) having a higher refractive index than air between the objective lens of the exposure machine and the sample. A so-called immersion lithography (hereinafter referred to as “immersion exposure”) is known (for example, see Non-Patent Document 1).
According to immersion exposure, even when a light source having the same exposure wavelength is used, the same high resolution as when using a light source with a shorter wavelength or using a high NA lens can be achieved, and the depth of focus can be reduced. It is said that there is no decline. In addition, immersion exposure can be performed by applying an existing exposure apparatus. For this reason, immersion exposure is expected to be able to form resist patterns with low cost, high resolution, and excellent depth of focus. In particular, in terms of lithography characteristics such as resolution, the semiconductor industry is attracting a great deal of attention.
Immersion exposure is effective in forming all pattern shapes, and can be combined with super-resolution techniques such as the phase shift method and the modified illumination method that are currently being studied. Currently, as an immersion exposure technique, a technique mainly using an ArF excimer laser as a light source is being actively researched. Currently, water is mainly studied as an immersion medium.

One recently proposed lithography technique is a double patterning process in which a resist pattern is formed by performing patterning twice or more (see, for example, Non-Patent Documents 2 to 3).
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 There is a method of repeating the above two times or more.
Formation of the pattern by the method (1) is performed, for example, according to the following procedure. First, a laminate in which a substrate, an underlayer film, and a hard mask are laminated is prepared. Next, a resist film is provided on the hard mask, and the resist film is selectively exposed through a photomask and developed, whereby a plurality of resist patterns of a predetermined size are arranged at predetermined positions. One resist pattern is formed. Next, after etching the hard mask using the first resist pattern as a mask, the remaining first resist pattern is removed. Thereby, a hard mask to which the first resist pattern is transferred is obtained. Next, by applying a resist composition on the hard mask, a resist film that fills the voids in the hard mask is formed. Then, the resist film is selectively exposed through a photomask having a different pattern arrangement and developed to form a second resist pattern. Next, after etching the hard mask using the second resist pattern as a mask, the remaining second resist pattern is removed. Thereby, a hard mask to which the first resist pattern and the second resist pattern are transferred is obtained. By performing etching using this hard mask as a mask, the pattern of the hard mask is transferred to the lower layer film, and as a result, a pattern having a narrower pitch than the photomask used is formed.
In the method (2), for example, a first resist film is formed on a support, a plurality of resist patterns are formed by patterning the first resist film, and then a second resist material is formed thereon. Is applied to form a second resist film that fills the gaps between the plurality of resist patterns, and the second resist film is patterned.
According to these double patterning processes, even if a light source having the same exposure wavelength is used or the same resist composition is used, the resolution is higher than that in the case of forming in one lithography process (single patterning). It is possible to form a resist pattern. The double patterning process can be performed using an existing exposure apparatus.

JP 2003-241385 A

Proceedings of SPIE, 5754, 119-128 (2005). Proceedings of SPIE, 5256, 985-994 (2003). Proceedings of SPIE, 6153, 615301-1-19 (2006).

When a space pattern or hole pattern is formed on a resist film, light that is forced to form a pattern under a weak light incident intensity compared to the case of forming a line pattern or dot pattern, and is incident on an exposed area and an unexposed area, respectively. The contrast of intensity is small. For this reason, the resolution and lithography margin in resist pattern formation (for example, allowance for exposure dose (EL margin), allowance for depth of focus (DOF margin), pattern shape verticality, etc.) are likely to be limited, and high resolution is achieved. It tends to be difficult to form an image resist pattern.
As a technique capable of forming a high-resolution resist pattern, it is conceivable to use a double patterning process as described above. However, in the double patterning process as described above, in the method (1), in order to form a pattern on the substrate, the resist film is patterned at least twice, and the underlying hard mask is etched at least twice. The increase in the number of steps, the increase in the amount of chemicals used, and the increase in the manufacturing cost associated therewith are problems. The method (2) is suitable for forming a line and space pattern, but is not suitable for forming an isolated space pattern (trench pattern) or a hole pattern.
Therefore, a new technique that can form a pattern such as a space pattern and a hole pattern with high resolution is required.
This invention is made | formed in view of the said situation, Comprising: It aims at providing the pattern formation method useful for formation of a fine pattern.

The present invention for solving the above-mentioned problems is to apply a first chemically amplified positive resist composition on a support to form a first resist film, expose the first resist film, and (1) performing baking and alkali development to form a first resist pattern;
On the support on which the first resist pattern is formed, a second film-forming material containing an organic solvent that does not dissolve the first resist film is applied to form a second film, Exposing the region of the second film including the position where the first resist pattern is formed, performing post-exposure baking, and alkali developing (2),
A chemically amplified or non-chemically amplified positive resist composition in which the second film-forming material has a higher energy amount than the first chemically amplified positive resist composition and has increased solubility in an alkaline developer. Or a resin composition whose solubility in an alkali developer does not change depending on the amount of energy or energy ,
In the step (2), the exposure amount and the post-exposure bake temperature are set so that only the first resist pattern in the exposed region is removed by alkali development.

Here, in the present specification and claims, “exposure” is a concept including general irradiation of radiation.
“Structural unit” means a monomer unit (monomer unit) constituting a resin component (polymer, copolymer).
Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups. Unless otherwise specified, the “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms. The “halogenated alkylene group” is a group in which part or all of the hydrogen atoms of the alkylene group are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
“Aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.

  ADVANTAGE OF THE INVENTION According to this invention, the pattern formation method useful for formation of a fine pattern can be provided.

It is a schematic process drawing explaining the preferable embodiment of the 1st patterning process in the pattern formation method of this invention. It is a schematic process drawing explaining the preferable embodiment of the 2nd patterning process in the pattern formation method of this invention. 6 is a graph showing the results of Test Example 1.

≪Pattern formation method≫
In the pattern forming method of the present invention, a first chemically amplified positive resist composition is coated on a support to form a first resist film, the first resist film is exposed, and post-exposure baking is performed. And (1) forming an alkali resist development to form a first resist pattern;
On the support on which the first resist pattern is formed, a second film forming material is applied to form a second film, and the first resist pattern of the second film is formed. A step (2) of exposing the region including the formed position, performing post-exposure baking, and alkali development.

Hereinafter, embodiments of the pattern forming method of the present invention will be described with reference to the drawings. However, the present invention is not limited to this.
1 and 2 show a first embodiment of the present invention.
In the present embodiment, step (1) is performed according to the procedure shown in FIG.
That is, first, as shown in FIG. 1A, a first resist film 2 is formed by applying a first chemically amplified positive resist composition on a support 1.
Next, as shown in FIG. 1B, the first resist film 2 is exposed through a photomask 3 on which a predetermined pattern is formed, and post-exposure baking (post-exposure baking (PEB)) is performed. . Thereby, the solubility with respect to the alkali developing solution of the exposed area | region (exposed part) among the 1st resist films 2 increases on the other hand, while the solubility with respect to the alkaline developing solution of the area | region (unexposed part) which is not exposed is increased. Does not change, or even if it changes, the amount of change is slight, so that there is a difference in dissolution rate (dissolution contrast) between the exposed portion and the unexposed portion in the alkaline developer. Therefore, when development is performed with an alkali developer, the exposed portion of the first resist film 2 is removed, and the unexposed portion remains, and as a result, as shown in FIG. A pattern (first resist pattern) composed of the plurality of arranged resist patterns 2a is formed.

Next, a process (2) is performed in the procedure shown in FIG.
In the step (2), first, on the support 1 (FIG. 2A) on which the first resist pattern is formed in the step (1), an organic solvent that does not dissolve the first resist film is contained, In addition, a second film-forming material that does not increase the solubility in an alkaline developer with an energy amount equal to or less than that of the first chemically amplified positive resist composition is applied, as shown in FIG. In this manner, the second film 6 that fills the gaps between the plurality of resist patterns 2a is formed.
Next, as shown in FIG. 2C, the second film 6 is exposed (entirely exposed) by open frame exposure (exposure not through a photomask), and PEB is performed.
At this time, the exposure amount in exposure and the baking temperature (PEB temperature) in PEB are set so that only the resist pattern 2a in the exposed region is removed by alkali development. When such exposure and PEB are performed, the solubility of the resist pattern 2a in the alkaline developer increases, whereas the solubility of the second resist film 6 filled between the resist patterns 2a in the alkaline developer hardly changes. When the development with an alkaline developer is performed, the resist pattern 2a is removed, while the second resist film 6 filled between the resist patterns 2a remains without being removed. A portion of the second resist film 6 existing on the upper surface of the resist pattern 2a is removed together with the resist pattern 2a at the time of alkali development because the thickness thereof is thin. As a result, as shown in FIG. 2D, a resist pattern (reversal pattern) obtained by reversing the image of the resist pattern 2a is formed at the position 6c where the resist pattern 2a was present.

Hereinafter, step (1) and step (2) in the first embodiment will be described in more detail.
[Step (1)]
The support is not particularly limited, and a conventionally known one can be used, and examples thereof include a substrate for electronic components and a substrate on which a predetermined wiring pattern is formed. 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.
Further, the support may be a substrate in which an inorganic and / or organic film is provided on the above-described substrate. 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 layer film) and at least one resist film are provided on a substrate, and the lower layer patterning is performed 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 first chemically amplified positive resist composition (hereinafter, simply referred to as “first positive resist composition”) is not particularly limited, and is a known chemically amplified positive resist composition. Can be appropriately selected and used.
Here, the “chemically amplified resist composition” contains an acid generator component that generates an acid upon exposure as an essential component, and an alkali of the entire chemically amplified resist composition by the action of the acid. It has the property of changing the solubility in a developer. For example, in the case of a positive type, the solubility in an alkali developer increases.
For example, as a chemically amplified positive resist composition, a compound in which a compound having an acid dissociable, dissolution inhibiting group (for example, a component (A) described later) is blended with the acid generator is generally used. . When exposure and post-exposure baking are performed on such a composition, the acid dissociable, dissolution inhibiting group is dissociated from the compound by the action of the acid generated from the acid generator component. This acid dissociable, dissolution inhibiting group is a group having an alkali dissolution inhibiting property that makes the entire compound difficult to dissolve in an alkali developer before dissociation and a property of dissociating with an acid generated from an acid generator component. Yes, the dissociation of the acid dissociable, dissolution inhibiting group increases the solubility of the compound in an alkaline developer. Therefore, when selective exposure and post-exposure baking are performed on the resist film formed using the chemically amplified positive resist composition, the exposed portion of the resist film is affected by the action of the acid generated from the acid generator component. As a result, the solubility in an alkali developer increases while the solubility in an unexposed portion does not change in the alkali developer. Therefore, only the exposed portion is dissolved and removed by alkali development, and a resist pattern is formed.
Specific examples of the first chemically amplified positive resist composition will be described later in detail.

A method for forming the first resist film 2 by applying the first positive resist composition on the support 1 is not particularly limited, and can be formed by a conventionally known method.
Specifically, for example, the first positive resist composition is applied onto the support 1 using a conventionally known method such as using a spinner, and baked (pre-baked) at a temperature of 80 to 150 ° C. Is applied for 40 to 120 seconds, preferably 60 to 90 seconds, and the first resist film 2 can be formed by volatilizing the organic solvent.
The thickness of the first resist film 2 is preferably 50 to 500 nm, more preferably 50 to 450 nm. By setting it within this range, there are effects that a resist pattern can be formed with high resolution and sufficient resistance to etching can be obtained.

Next, the first resist film 2 formed as described above is selectively exposed through a photomask 3, subjected to PEB treatment, and developed to form a first resist pattern.
The wavelength used for the exposure is not particularly limited, and includes KrF excimer laser, ArF 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. One of ArF excimer laser, EUV, and EB is preferable because a fine resist pattern can be easily formed, and ArF excimer laser is particularly preferable.
The photomask is not particularly limited, and a known one can be used. For example, a binary mask (Binary-Mask) in which the transmittance of the light shielding portion is 0%, or a halftone type phase in which the transmittance of the light shielding portion is 6%. A shift mask (HT-Mask) can be used.
The binary mask is generally formed by forming a chromium film, a chromium oxide film or the like as a light shielding portion on a quartz glass substrate.
As the halftone phase shift mask, generally, a quartz glass substrate on which a MoSi (molybdenum silicide) film, a chromium film, a chromium oxide film, a silicon oxynitride film, or the like is formed as a light shielding portion is used. .
In the present embodiment, the exposure is performed through the photomask 3, but the present invention is not limited to this, and the selective exposure may be performed by exposure without using the photomask, for example, drawing by EB or the like.

The exposure of the first resist film 2 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, as described above, at the time of exposure, the portion between the lens, which is conventionally filled with an inert gas such as air or nitrogen, and the resist film on the support is larger than the refractive index of air. Exposure is performed in a state filled with a solvent having a refractive index (immersion medium).
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 (first resist film 2 in step (1)) exposed by the immersion exposure. Is preferred. 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 step (1), the exposure amount and the PEB temperature are set so that the solubility of the exposed portion of the first resist film 2 in the alkaline developer increases. That is, the amount of energy supplied to the exposed portion of the first resist film 2 by exposure and PEB increases the solubility of the exposed portion in the alkaline developer, while the solubility of the unexposed portion in the alkaline developer is Exposure and PEB are performed so that the amount of energy does not increase.
More specifically, the first resist film 2 made of a chemically amplified positive resist composition is subjected to exposure and PEB to generate an acid from the acid generator component, and the resist film of the generated acid. 2 and the increase in the solubility of the resist film in the alkaline developer by the action of the acid proceeds. At this time, if the exposure amount and the baking temperature (PEB temperature) of PEB are not sufficient, and the amount of energy supplied is not sufficient, the generation and diffusion of acid does not proceed sufficiently in the exposed portion, and alkali development in the exposed portion is performed. The solubility in the liquid does not increase sufficiently. For this reason, the difference in dissolution rate (dissolution contrast) between the exposed portion and the unexposed portion in the alkaline developer is small, and a good resist pattern cannot be formed even when developed. That is, in order to form the first resist pattern, when the first resist film 2 is exposed, PEB, and developed, the exposed portion of the resist film 2 is dissolved and removed with an alkaline developer. Therefore, it is necessary to perform exposure and PEB at an exposure amount and PEB temperature that exhibit sufficient alkali developer solubility.
In order to increase the solubility of the first resist film 2 in the alkaline developer, both the exposure amount and the PEB temperature need to have values of a certain level or more. For example, if the exposure amount is too small, no increase in solubility in an alkaline developer is observed even when the PEB temperature is increased. Even if the exposure amount is large, if the PEB temperature is too low, an increase in solubility in an alkaline developer is not observed.
Hereinafter, the PEB temperature at which the resist film after exposure can exhibit sufficient alkali developer solubility to be dissolved and removed with an alkali developer may be referred to as an effective PEB temperature.

Among the above, the exposure amount may be a temperature that can increase the solubility of the first resist film 2 in the alkaline developer, and the optimum exposure amount (Eop ₁ ) of the first resist film 2 is usually used. It is done. Here, the “optimal exposure amount” means that when the resist film is selectively exposed, PEB is performed at a predetermined PEB temperature and developed, the resist pattern is faithfully reproduced according to the design pattern dimensions. The exposure amount.
The PEB temperature (T _peb1 ) in the step (1) is a temperature that can increase the solubility of the exposed portion of the first resist film 2 exposed at the exposure amount in the alkaline developer, that is, the first resist. What is necessary is _just the temperature more than the minimum value ( _Tmin1 ) of the effective PEB temperature of the film _| membrane 2. That is, T _min1 ≦ T _peb1 is sufficient.
T _peb1 varies depending on the composition of the first positive resist composition to be used, but is usually in the range of 70 to 150 ° C, preferably 80 to 140 ° C, and more preferably 85 to 135 ° C.
The baking time in the PEB treatment is usually 40 to 120 seconds, preferably 60 to 90 seconds.

Whether the exposure amount to be applied and the PEB temperature increase the solubility of the first resist film 2 in the alkaline developer can be determined by the following procedure.
The first resist film 2 is exposed by changing the exposure amount with an exposure light source (for example, ArF excimer laser, EB, EUV, etc.) used in step (1), and is exposed at a predetermined baking temperature for 30 to 120 seconds. The PEB process is performed, and development is performed using a 2.38 mass% tetramethylammonium hydroxide aqueous solution (23 ° C.) as a developer.
At this time, when the exposure amount is increased at a predetermined baking temperature and the exposure amount becomes a predetermined value or more, the dissolution rate of the exposed portion of the first resist film 2 in the alkaline developer is 1 nm / second or more. In this case, it is determined that the baking temperature is a baking temperature that increases the solubility of the first resist film 2 in the alkaline developer (a temperature _{equal to} or higher than T _{min1 of} the first resist film 2). On the other hand, even when the exposure amount is increased, the dissolution rate of the exposed portion of the first resist film 2 in the developer does not become 1 nm / second or more, and when saturation is exhibited at a lower dissolution rate, It is determined that the baking temperature is a baking temperature that does not increase the solubility of the first resist film 2 in the alkaline developer (a temperature _lower than T _{min1 of} the first resist film 2).
At this time, the exposure amount equal to or higher than the exposure amount at the time when the change in dissolution rate in the alkaline developer becomes 1 nm / second or more is the solubility of the first resist film 2 in the alkaline developer at the PEB temperature. It is determined that the exposure amount increases the amount of exposure.

After the PEB treatment, alkali development of the first resist film 2 is performed. Alkali development can be carried out by a known method using an aqueous alkali solution generally used as a developer, for example, an aqueous tetramethylammonium hydroxide (TMAH) solution having a concentration of 0.1 to 10% by mass. By such alkali development, the exposed portion of the first resist film 2 is removed to form a resist pattern 2a.
After the alkali development, a rinse treatment with water or the like may be performed.

In the present invention, after the alkali development or the rinsing treatment, it is preferable to perform a baking treatment (post-baking) in order to reduce the organic solvent remaining in the resist pattern 2a. When the organic solvent is reduced, the resistance of the resist pattern 2a to the organic solvent is improved. When the second film forming material is applied in the step (2), the resist pattern by the organic solvent contained in the film forming material. The damage to 2a can be suppressed.
Although the post-baking temperature varies depending on the organic solvent used in the first positive resist composition, it is usually preferably 130 ° C. or higher, more preferably 130 to 160 ° C. If the baking temperature is too low, the organic solvent cannot be reduced sufficiently, and if it is too high, the shape of the resist pattern 2a may be deteriorated by the heat.
The post-baking time varies depending on the baking temperature, but is usually about 30 to 90 seconds.

[Step (2)]
Next, the support 1 on which the first resist pattern is formed contains an organic solvent that does not dissolve the first resist film (hereinafter referred to as (S ′) component), and the first positive pattern is formed. A second film forming material is applied which fills the gaps between the resist patterns 2a by applying a second film-forming material that does not increase the solubility in an alkaline developer with an energy amount equal to or less than that of the resist composition. To do.
When the second film forming material contains the component (S ′), the resist pattern 2a is dissolved by the organic solvent in the second film forming material when the second film forming material is applied. It is possible to suppress the deterioration and disappearance of the shape of the resist pattern 2a, the mixing at the interface between the resist pattern 2a and the second film 6, and the like.
In addition, as described above, the second film-forming material does not increase the solubility in an alkaline developer with an energy amount equal to or less than that of the first positive resist composition. A pattern can be formed.

Here, “does not dissolve the first resist film” in the component (S ′) means that the first positive resist composition is applied on a support and dried, and the film thickness is 0 at 23 ° C. When a resist film having a thickness of 2 μm is formed and immersed in the organic solvent, the resist film disappears or the film thickness does not change significantly even after 60 minutes (preferably the film of the resist film The thickness does not become 0.16 μm or less.)
As the component (S ′), any component that does not dissolve the first resist film and can dissolve the components blended in the second film-forming material may be used.
Specific examples include alcohol-based organic solvents, fluorine-based organic solvents, and ether-based organic solvents having no hydroxyl group. Any one of these may be used alone, or two or more thereof may be mixed and used. Alcohol-based organic solvents are preferred from the viewpoint of applicability and solubility of materials such as resin components.
Here, the “alcohol-based organic solvent” is a compound in which at least one of the hydrogen atoms of the aliphatic hydrocarbon is substituted with a hydroxyl group, and is a compound that is liquid at normal temperature and normal pressure. The structure of the main chain constituting the aliphatic hydrocarbon may be a chain structure, may be a cyclic structure, may have a cyclic structure in the chain structure, The chain structure may contain an ether bond.
The “fluorine-based organic 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 organic solvent, monohydric alcohols, dihydric alcohols, derivatives of dihydric alcohols, and the like are preferable.
As the monohydric alcohol, although depending on the number of carbon atoms, a primary or secondary monohydric alcohol is preferable, and a primary monohydric alcohol is most preferable.
Here, the monohydric alcohol means a compound in which one of the hydrogen atoms of a hydrocarbon compound composed only of carbon and hydrogen is substituted with a hydroxyl group, and does not include a dihydric or higher polyhydric alcohol derivative. The hydrocarbon compound may have a chain structure or a cyclic structure.
The dihydric alcohol means a compound in which two hydrogen atoms of the hydrocarbon compound are substituted with a hydroxyl group, and does not include a trihydric or higher polyhydric alcohol derivative.
Examples of the dihydric alcohol derivative include compounds in which one of the hydroxyl groups of the dihydric alcohol is substituted with a substituent (such as an alkoxy group or an alkoxyalkyloxy group).

The boiling point of the alcohol-based organic 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. And the most preferable from the viewpoint of the heating temperature in the PEB process.
Specific examples of such alcohol-based organic solvents include those having a chain structure such as propylene glycol (PG); 1-butoxy-2-propanol (BP), n-hexanol, 2-heptanol, 3-heptanol, and 1-heptanol. 5-methyl-1-hexanol, 6-methyl-2-heptanol, 1-octanol, 2-octanol, 3-octanol, 4-octanol, 2-ethyl-1-hexanol, 2- (2-butoxyethoxy) ethanol N-pentyl alcohol, s-pentyl alcohol, t-pentyl alcohol, isopentyl alcohol, isobutanol (also referred to as isobutyl alcohol or 2-methyl-1-propanol), isopropyl alcohol, 2-ethylbutanol, neopentyl alcohol, n-bu Nord, s- butanol, t-butanol, 1-propanol, 2-methyl-1-butanol, 2-methyl-2-butanol, 4-methyl-2-pentanol.
In addition, as those having a cyclic structure, cyclopentanemethanol, 1-cyclopentylethanol, cyclohexanol, cyclohexanemethanol (CM), cyclohexaneethanol, 1,2,3,6-tetrahydrobenzyl alcohol, exo-norbornol, 2-methyl Examples include cyclohexanol, cycloheptanol, 3,5-dimethylcyclohexanol, and benzyl alcohol.

  Among alcohol-based organic solvents, chain-structured monohydric alcohols or dihydric alcohol derivatives are preferable, such as 1-butoxy-2-propanol (BP); isobutanol (2-methyl-1-propanol), 4-methyl. 2-Pentanol and n-butanol are preferred, and isobutanol (2-methyl-1-propanol) and 1-butoxy-2-propanol (BP) are most preferred.

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

Preferred examples of the ether organic solvent having no hydroxyl group include compounds represented by the following general formula (s-1).
R ⁴⁰ —O—R ⁴¹ (s-1)
[Wherein, R ⁴⁰ and R ⁴¹ each independently represent a monovalent hydrocarbon group, and R ⁴⁰ and R ⁴¹ may combine 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, more preferably 1 to 10 carbon atoms, because the coating properties of the 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 less likely to evaporate during spin coating during application of the resist composition, so that application unevenness is suppressed and application 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. Further, when the temperature is within this range, the resist pattern film thickness reduction effect 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 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.

The (S ′) component used for the second film-forming material may be a single type or two or more types.
The second film-forming material contains an organic solvent other than the (S ′) component (hereinafter referred to as the (S ″) component) as long as the effect of using the (S ′) component is not impaired. May be.
The component (S ″) is preferably a component capable of dissolving the component blended in the second film-forming material. Specifically, it will be mentioned in the description of the first positive resist composition described later (S). The thing similar to an ingredient is mentioned.
The compounding amount of the component (S ″) is preferably 0 to 20% by mass and more preferably 1 to 15% by mass in the total organic solvent used for the second film-forming material.
The amount of the total organic solvent used for the second film-forming material is not particularly limited, and usually the amount that makes the second film-forming material a liquid having a concentration that can be applied on the support is used. It is done.

Examples of a material whose solubility in an alkali developer does not increase with an energy amount equal to or less than that of the first positive resist composition include, for example, an alkali with a higher energy amount than that of the first positive resist composition. Chemically amplified or non-chemically amplified positive resist composition with increased solubility in developer, resin having solubility in a predetermined alkali developer (solubility in alkali developer hardly changes depending on the amount of energy) Examples thereof include compositions.
Among these, a chemically amplified positive resist composition that has a higher energy amount and higher solubility in an alkaline developer than the first positive resist composition is preferable. When the chemical amplification type positive resist composition is used, the second film 6 formed in the step (2) can be partially exposed, and a reversal pattern can be formed only on the exposed portion, so that a complicated structure pattern can be formed. Can be formed. Further, a pattern having a complicated structure can be formed by separately performing selective exposure, PEB, and alkali development on the unexposed portion of the second film 6.
However, the present invention is not limited to this, and a non-chemically amplified positive resist composition may be used. Moreover, you may use the resin composition which has the solubility with respect to a predetermined alkali developing solution (the solubility with respect to an alkaline developing solution hardly changes with energy amount). The resin component in the resin composition is, for example, a resin component that does not have a structural unit containing an acid dissociable, dissolution inhibiting group such as the structural unit (a1) described later, and includes the structural unit (a3) (in particular, the formula A resin component containing (the structural unit represented by (a3-3)) is preferred.
Specific examples of the composition of the chemically amplified positive resist composition (hereinafter sometimes referred to as the second positive resist composition) used as the second film forming material will be described later in detail. What is necessary is just to set suitably according to the composition of this positive resist composition. For example, when the first positive resist composition containing an acid generator component (B) that generates an acid upon exposure and a base material component (A) having an acid dissociable, dissolution inhibiting group is used, The positive resist composition contains an acid generator component (B ′) that generates an acid upon exposure and a base component (A ′) having an acid dissociable, dissolution inhibiting group, and the base component (A ′ ) Has an acid dissociable, dissolution inhibiting group having a higher deprotection energy than the acid dissociable, dissolution inhibiting group of the substrate component (A).
The first positive resist composition and the second positive resist composition are known chemical amplifications in consideration of lithography conditions (exposure amount, PEB temperature, etc.) in step (1) and step (2), respectively. It can be appropriately selected from the type positive resist compositions. The method for selecting the first positive resist composition and the second positive resist composition will be described in detail later.

Similar to the first resist film 2, the second film 6 can be formed by a conventionally known method.
In the present invention, the film thickness of the second film 6 (the minimum value of the film thickness of the portion filling the gap between the resist patterns 2a) is equal to or less than the height of the resist pattern 2a. preferable. In this case, the thickness of the second film 6 covering the upper surface of the resist pattern 2a is thin enough to be easily removed during alkali development in the step (2). That is, the film 6 in this portion has a small film thickness (thickness on the upper side from the upper end of the resist pattern 2a). Therefore, it is dissolved and removed together with the resist pattern 2a during development. Therefore, the reverse pattern can be formed satisfactorily.
On the other hand, if the thickness of the second film 6 is too thick, the second film 6 on the upper surface of the resist pattern 2a cannot be removed well during alkali development in the step (2), and a good reverse pattern may not be formed. .

Next, the second resist film 6 formed as described above is exposed (entire exposure) by open frame exposure (exposure not through a photomask), and PEB is performed.
At this time, as described above, the exposure amount in exposure and the PEB temperature are set so that only the resist pattern 2a in the exposed region is removed by alkali development.
That is, the amount of energy supplied to the resist pattern 2a and the second film 6 by exposure and PEB increases the solubility of the resist pattern 2a in the alkaline developer, while the solubility of the second film 6 in the alkaline developer. The exposure and PEB are performed so that the energy amount does not increase.
When such exposure and PEB are performed, the solubility of the resist pattern 2a in the alkaline developer increases, whereas the solubility of the second resist film 6 filled between the resist patterns 2a in the alkaline developer hardly changes. When the development with an alkaline developer is performed, the resist pattern 2a is removed, while the second resist film 6 filled between the resist patterns 2a remains without being removed. A portion of the second resist film 6 existing on the upper surface of the resist pattern 2a is removed together with the resist pattern 2a at the time of alkali development because the thickness thereof is thin.
As a result, as shown in FIG. 2D, a pattern (reversal pattern) in which the image of the resist pattern 2a is reversed is formed at the position 6c where the resist pattern 2a was present.
For example, when the resist pattern 2a is a line pattern, a space pattern having the same dimension (space width) as the dimension (line width) of the line pattern is formed as an inverted pattern at the same position as the line pattern. When the resist pattern 2a is a dot pattern, a hole pattern having the same dimension (hole diameter) as that of the dot pattern is formed as an inverted pattern at the same position as the dot pattern.

The exposure amount in the step (2) is not particularly limited as long as the solubility of the resist pattern 2a in the alkaline developer after exposure and PEB is increased and the solubility of the second film 6 in the alkaline developer is not increased. .
In the case of performing the exposure by the entire surface exposure, the incident energy amount is large even with the same exposure amount as compared with the case of performing the selective exposure through the mask pattern, and the exposure amount is smaller than the exposure amount in the step (1). Even if it exists, the solubility with respect to the alkaline developing solution of the resist pattern 2a can be increased. Therefore, the exposure amount in the step (2) may be equal to or more than the exposure amount (for example, Eop ₁ ) in the step (1), or may be small.
However, when the above-mentioned chemical amplification type or non-chemical amplification type positive resist composition is used as the second film forming material, the exposure amount in the step (2) is the second exposure amount exposed at the exposure amount. It is necessary that the exposure amount be such that the solubility of the exposed portion of the film 6 in the alkaline developer does not increase.
Similarly, the PEB temperature in the step (2) should be within a range in which the solubility of the resist pattern 2a in the alkaline developer after exposure and PEB is increased and the solubility of the second film 6 in the alkaline developer is not increased. There is no particular limitation.

Whether the exposure amount and the PEB temperature in the step (2) are the exposure amount and the baking temperature that increase the solubility of the resist pattern 2a in the alkaline developer can be determined by the procedure described in the step (1).
Further, whether or not the exposure amount and the PEB temperature in the step (2) are the exposure amount and the baking temperature that do not increase the solubility of the second film 6 in the alkaline developer can be determined by the following procedure.
The second film 6 is exposed (entire exposure) by changing the exposure amount with an exposure light source (for example, ArF excimer laser, EB / EUV, etc.) used in step (2), and is exposed at a predetermined baking temperature. PEB treatment is performed for ˜120 seconds, and development is performed using a 2.38 mass% tetramethylammonium hydroxide aqueous solution (23 ° C.) as a developer.
At this time, when (I) the exposure amount is increased, it is only necessary to confirm that the exposed portion of the second film 6 is left with a predetermined exposure amount or more.
If a remaining film of at least 70% or more can be confirmed, it is determined that the exposure amount and the baking temperature are baking temperatures that do not increase the solubility of the second film 6 in the alkaline developer. On the other hand, when the exposure amount is increased, if the remaining film of 70% or more cannot be confirmed in the exposed portion of the second film 6, the baking temperature is higher than the alkaline developer of the second resist film. It is determined that the baking temperature increases the solubility.
Here, the remaining film (%) is the ratio (%) of the “film thickness of the resist film after exposure, PEB and development” to the “film thickness of the resist film before exposure, PEB and development”. is there.
Alternatively, (II) even when the exposure amount is increased, the dissolution rate of the exposed portion of the second film 6 in the developer does not become 1 nm / second or more, and saturation is exhibited at a lower dissolution rate. The baking temperature is determined to be a baking temperature that does not increase the solubility of the second film 6 in the alkaline developer.
On the other hand, when the exposure amount is increased and the dissolution rate of the exposed portion of the second film 6 in the developing solution is 1 nm / second or more, the baking temperature is alkali development of the second film 6. It is determined that the baking temperature increases the solubility in the liquid.
At this time, the exposure amount at which the dissolution rate in the alkaline developer does not change is 1 nm / second or more is the exposure amount that does not increase the solubility of the second film 6 in the alkaline developer at the PEB temperature. It is determined.

The PEB temperature (T _peb2 ) in the step (2) may be any temperature that can increase the solubility of the resist pattern 2a exposed at a predetermined exposure amount in an alkaline developer. As such a temperature, for example, a temperature equal to or higher than T _min1 (the lowest effective PEB temperature of the first resist film 2) is preferable. That is, it is preferable that T _peb2 ≧ T _min1 .
Further, T _peb2 needs to be a temperature lower than the lowest effective PEB temperature of the second film 6. That is, if the minimum value of the effective PEB temperature of the second film 6 is T _min2 , T _peb2 <T _min2 .
Therefore, T _peb2 is set in consideration of T _min1 , T _min2, etc. so as to satisfy T _min1 ≦ T _peb2 <T _min2 .
In order to set T _peb2 to satisfy T _min1 ≦ T _peb2 <T _min2 , it is necessary to make T _min2 higher than T _min1 .
T _min1 and T _min2 are different depending on the composition of the positive resist composition used, and the composition of each positive resist composition is the PEB temperature, exposure light source, exposure in the steps (1) to (2). What is necessary is just to determine suitably, considering lithography conditions, such as quantity.
The difference between T _min1 and T _min2 is preferably 10 ° C. or higher, more preferably 15 ° C. or higher, and further preferably 30 ° C. or higher. The greater the difference, the better the effect of the present invention. In addition, there is an advantage that the margin of the process is improved. The upper limit of the difference is not particularly limited, but is preferably 50 ° C. or lower in consideration of the device surface.
The difference between T _min1 and T _min2 can be adjusted by adjusting the composition of the first positive resist composition and the second film forming material used.
For example, the first positive resist composition and the second film-forming material are both chemically amplified resist compositions, and an acid generator component that generates an acid upon exposure (for example, a component (B) described later, (B ') Component) and a base component having an acid dissociable, dissolution inhibiting group (for example, (A) component, (A') component described later), an acid dissociable, dissolution inhibiting group in the second film-forming material. However, if the deprotection energy is higher than that of the acid dissociable, dissolution inhibiting group in the first positive resist composition, T _min2 is higher than T _min1 .
In addition, as the acid generator component of the first positive resist composition, the acid generating component is a relatively strong acid, and as the acid generator component of the second film forming material, the generated acid is relatively by the use of what is a weak _acid, it can be higher than the _{T min2 T min1.}
For details on the combination of acid dissociable, dissolution inhibiting groups and the combination of acid generator components in the first chemically amplified resist composition and the second chemically amplified resist composition, the first positive resist composition The method for selecting the product and the second positive resist composition will be described later.

T _peb2 varies depending on the composition of the second film forming material to be used, but is usually in the range of 70 to 150 ° C, preferably 80 to 140 ° C, and more preferably 85 to 135 ° C. The baking time is usually 40 to 120 seconds, preferably 60 to 90 seconds.

After the PEB, the second film 6 is developed. Thereby, the resist pattern 2a is removed, and a reverse pattern is formed.
Development can be carried out by a known method using an aqueous alkali solution, for example, an aqueous tetramethylammonium hydroxide (TMAH) solution having a concentration of 0.1 to 10% by mass.
After the alkali development, a rinse treatment with water or the like may be performed.
Further, after the alkali development, a baking process (post-bake) may be further performed. Post baking is usually performed under conditions of about 100 ° C. (because it is performed for the purpose of removing water after alkali development and rinsing), and the processing time is preferably 30 to 90 seconds.

In this embodiment, a space pattern and / or a hole pattern can be obtained as an inverted pattern by forming a line pattern and / or a dot pattern as the resist pattern 2a.
Thus, the space pattern and hole pattern formed as a reversal pattern have a resolution, a shape, a lithography margin (for example, a margin with respect to an exposure amount (EL margin), a focal point, and the like, compared with a case where the space pattern and hole pattern are directly formed in one lithography process. It is excellent in pattern forming ability such as a margin with respect to depth (DOF margin), verticality of pattern shape, and the like. That is, when directly forming a space pattern or a hole pattern that requires removal of a very small part of the resist film or a fine region, as described above, pattern formation under weak light incident intensity is forced. However, the pattern forming ability when forming the reverse pattern depends on the pattern forming ability when forming the first resist pattern (isolated line pattern, dot pattern, line and space pattern, etc.). Compared with the case of directly forming a space pattern or a hole pattern, the pattern forming ability is less limited, and a good resist pattern can be formed.

In the first embodiment, the case where the entire surface exposure is performed in the step (2) is shown. However, the present invention is not limited to this, and a partial region of the second film 6 (however, in the region) , Including a position where at least a part of the resist pattern 2a is formed) may be selectively exposed. In this case, a reverse pattern can be formed only in the exposed portion.
In the present invention, after the step (2), the same step as the step (2) may be repeated once or a plurality of times. Thereby, a pattern with a more complicated shape can be formed.
When a positive resist composition is used as the second film forming material, the second film 6 may be patterned after the step (2). That is, the second film 6 on which the reverse pattern is formed as described above may be selectively exposed and developed to form a resist pattern. Thereby, a denser pattern with a narrower pitch or a pattern with a complicated shape can be formed.
Moreover, in this invention, you may etch the support body 1 using the formed pattern as a mask after the said process (2). A semiconductor device or the like can be manufactured by etching the support 1.
A known method can be used as the etching method. For example, the etching of the organic film (resist pattern, organic antireflection film, etc.) is preferably dry etching. In particular, oxygen plasma etching or etching using CF ₄ gas or CHF ₃ gas is preferable, and oxygen plasma etching is particularly preferable. Etching of the substrate and the inorganic antireflection film is preferably performed using a halogen gas, more preferably using a fluorocarbon gas, and particularly preferably using a CF ₄ gas or a CHF ₃ gas.

In the first embodiment, in the step (1), the first resist pattern is formed by single patterning in which a series of lithography steps from application of the resist composition to exposure and development are performed once. Without being limited thereto, the first resist pattern may be formed by a double patterning process. As described above, the double patterning process is a lithography technique in which patterning is performed twice or more to form a resist pattern. According to the double patterning process, even when a light source having the same exposure wavelength is used, the same resist composition is used. Even if it is used, it is possible to form a resist pattern having higher resolution than single patterning. The double patterning process can be performed using an existing exposure apparatus.
As the double patterning process, the above-described (1) lithography process (from resist composition application to exposure and development) and etching process are repeated twice or more, and (2) the lithography process is repeated twice. The method of repeating above is mentioned, and the method (2) is particularly preferable.

  More specifically, as the method for forming the first resist pattern by the method (2), a chemically amplified positive resist composition (hereinafter referred to as a resist composition) for patterning for the first time on a support. [1]) is applied to form a resist film [1], the resist film [1] is selectively exposed, PEB is performed, and alkali development is performed to form a resist pattern [1]. And a chemical amplification type positive resist composition (hereinafter referred to as resist composition [2] for the second patterning on the support on which the resist pattern [1] is formed). 2]) to form a resist film [2], the resist film [2] is selectively exposed, PEB is performed, alkali development is performed, and the resist pattern [1] is formed. There forming a resist pattern in a region including a position not formed (hereinafter, referred to as 2nd patterning step.) And include a method comprising the.

In the 1st patterning step, the resist composition [1] may be the same as the first positive resist composition used in step (1) in the description of the first embodiment.
A series of steps from formation of the resist film [1] to selective exposure and alkali development can be performed in the same manner as the step (1) in the first embodiment.

In the 2nd patterning step, first, a resist composition [2] is applied to the support on which the resist pattern [1] is formed to form a resist film [2].
As resist composition [2], the thing similar to what was mentioned as a 1st positive resist composition used at a process (1) in the said 1st Embodiment is mentioned.
However, the organic solvent (hereinafter referred to as 2nd solvent) contained in the resist composition [2] is preferably an organic solvent that does not dissolve the resist film [1]. Thereby, dissolution of the resist pattern [1] by the organic solvent in the resist composition [2] when the resist composition [2] is applied can be suppressed, and the shape of the resist pattern [1] is deteriorated or disappeared. Generation of mixing at the interface between the pattern [1] and the resist film [2] can be prevented.
Examples of the 2nd solvent include the (S ′) component, a mixed solvent of the (S ′) component and the (S ″) component (an organic solvent other than the (S ′) component), and the like. It is preferable to contain an alcohol organic solvent from the viewpoint of the solubility of the material such as the property and the resin component.
However, the organic solvent contained in the second film-forming material used in the next step (2) dissolves the first positive resist composition (resist compositions [1] and [2] in the present embodiment). Therefore, the 2nd solvent is usually different from the organic solvent contained in the second film forming material used in the step (2).
As an example of a preferable combination of the 2nd solvent and the organic solvent of the second film forming material, for example, as the 2nd solvent, the solubility of the resist composition [2] rather than 1-butoxy-2-propanol (BP) and BP Use a mixed solvent with a high solvent (for example, the (S) component mentioned in the description of the first positive resist composition described later), and use only isobutanol as the organic solvent for the second film-forming material. Can be mentioned.

Further, the resist composition [2] preferably has increased solubility in an alkaline developer with a smaller amount of energy than the resist composition [1]. That is, it is preferable that the resist composition [1] does not increase the solubility in an alkali developer when the energy amount is the same as or less than that of the resist composition [2].
That is, the positive resist composition is used in both the 1st patterning step and the 2nd patterning step, and the exposed portions of both the resist films [1] and [2] are dissolved and removed by the alkali developer. In the 2nd patterning process, the resist pattern [2] is exposed in the region including the position where the resist pattern [1] is formed because the resist pattern is formed in the region including the position where the resist pattern [1] is not formed. May be. At this time, if the resist composition [2] does not increase the solubility in an alkali developer with an energy amount smaller than that of the resist composition [1], the resist pattern [1] is obtained by exposure and PEB in the 2nd patterning step. ] In an alkaline developer, and may be dissolved and removed together with the exposed portion of the resist film [2] during alkali development in the 2nd patterning step. On the other hand, as the resist composition [2], by using a resist composition having increased solubility in an alkaline developer with an energy amount smaller than that of the resist composition [1], the first resist pattern is formed by the double patterning process. Can be performed satisfactorily.

The selection of the resist composition [1] and the resist composition [2] can be carried out in the same manner as the selection of the second positive resist composition and the first positive resist composition, respectively.
For example, both the resist composition [1] and the resist composition [2] include an acid generator component (B) that generates an acid upon exposure and a base material component (A) having an acid dissociable, dissolution inhibiting group. In the case, the resist composition [1] is alkali-developed with an energy amount equal to or less than that of the resist composition [2] in the same manner as the methods (2a) to (2c) described in the selection method section described later. It can be assumed that the solubility in the liquid does not increase. Among these, the methods (2a) to (2b) are preferable. That is, the following methods (2a ′) to (2b ′) can increase the solubility of the resist composition [2] in an alkali developer with an energy amount smaller than that of the resist composition [1]. .
(2a ′) Acid dissociation property having a lower deprotection energy than the acid dissociable, dissolution inhibiting group of the base material component (A) of the resist composition [1] as the base material component (A) of the resist composition [2] A method using one having a dissolution inhibiting group.
(2b ′) A method of using a resist composition [2] that is more susceptible to exposure and / or PEB damage than the base composition (A) of the resist composition [1] as the base composition (A) of the resist composition [2].
Among these, the method (2a ′) is preferable.
Any 1 type may be used for the said method (2a ')-(2b'), and 2 or more types may be used together.
However, in the next step (2), the “second film-forming material that does not increase the solubility in an alkali developer with the same amount of energy as or less than that of the first chemically amplified positive resist composition” is used. Therefore, both of the resist compositions [1] and [2] need to increase the solubility in the alkaline developer with an energy amount that does not increase the solubility of the second film-forming material in the alkaline developer. There is.
For example, when applying the above methods (2a ′) and (2a) utilizing the difference in deprotection energy of acid dissociable, dissolution inhibiting groups, resist composition [1], resist composition [2], second positive type Each of the resist compositions is blended so that the deprotection energy of the acid dissociable, dissolution inhibiting group contained is second positive resist composition> resist composition [1]> resist composition [2]. It is preferable to select the base material component (A) and the base material component (A ′).

The resist film [2] can be formed by a conventionally known method, like the first resist film in the first embodiment.
The film thickness of the resist film [2] is preferably at least equal to or higher than the height of the resist pattern [1]. That is, the surface of the support is preferably flat when viewed from the resist film [2] side.

Next, the resist film [2] is selectively exposed, PEB is performed, and alkali development is performed to form a resist pattern in a region including a position where the resist pattern [1] is not formed. Thereby, the 1st resist pattern which consists of said resist pattern [1] and the resist pattern newly formed in resist film [2] is formed on a support body.
Here, except for the case where it completely coincides with the position where the resist pattern [1] is formed, all are “regions including positions where the resist pattern [1] is not formed”, and the resist pattern [1] is formed. The case where the position does not overlap at all and the case where the position overlaps with the position where the resist pattern [1] is formed are included.
The resist pattern can be formed, for example, by performing selective exposure by the following method (a) or (b).
(A) A method of shifting the exposure position using the same photomask as the photomask used in the 1st patterning process (for example, moving or rotating the photomask used in the 1st patterning process in parallel or rotating) Etc.),
(B) A method using a photomask in which a pattern different from the photomask used in the 1st patterning process is formed (for example, a line and space pattern photomask is used in the 1st patterning process, and a hole pattern photomask is used in the 2nd patterning process). Etc.).

The exposure and PEB of the resist film [2] are performed so that the solubility of the resist film [2] in the exposed portion in the alkaline developer increases and the solubility of the resist pattern [1] in the alkaline developer does not increase. Set the amount and PEB temperature.
That is, the amount of energy supplied to the resist pattern [1] and the resist film [2] by exposure and PEB increases the solubility of the resist film [2] in the exposed portion in the alkaline developer, while the resist pattern [1] The exposure and PEB are performed so that the solubility of the resin in the alkali developer does not increase.
When such exposure and PEB are performed, the solubility of the resist film [2] in the alkaline developer in the exposed area increases, while the solubility of the resist pattern [1] in the alkaline developer hardly changes. When the development is performed, the exposed portion of the resist film [2] is removed, while the resist pattern [1] remains without being removed. As a result, a first resist pattern composed of the resist pattern [1] and a resist pattern newly formed on the resist film [2] is formed on the support.
The exposure amount and PEB temperature in the 2nd patterning step are the same as the exposure amount and PEB temperature set in step (2) described in the first embodiment, but the solubility of the resist pattern 2a in the alkaline developer increases after exposure and PEB. In addition, from the condition that the solubility of the second film 6 in the alkaline developer does not increase, the solubility of the resist film [2] in the alkaline developer increases after exposure and PEB, and the alkali development of the resist pattern [1] occurs. It can set similarly except changing to the conditions which the solubility with respect to a liquid does not increase.

When forming a resist pattern (line and space pattern) in which a plurality of lines are arranged at intervals or a resist pattern (hole pattern) in which a plurality of holes are arranged at intervals as the first resist pattern In the 2nd patterning step, it is preferable to form the resist pattern so as not to overlap at all with the position where the resist pattern [1] is formed. As a result, a new resist pattern is formed between each of the plurality of resist patterns [1]. As a result, a resist pattern having a narrower pitch than the resist pattern [1] formed in the first patterning step can be formed.
For example, when a line and space pattern is formed as an example, a line and space sparse pattern is formed using a line and space pattern photomask in which a plurality of lines are arranged at a constant pitch in the first patterning step. Later, in the 2nd patterning process, by forming a line having the same line width at an intermediate position between the lines formed in the 1st patterning process, a dense pattern with a narrower line and space than the sparse pattern formed first is formed. It is formed.
Here, the “sparse pattern” means a line and space pattern in which a line width: space width = 1: 2 or more is wide in a line and space resist pattern, and a dense pattern is a line width: space width. = 1: A line and space pattern having a space width narrower than 2:
More specifically, for example, after forming a line-and-space pattern (sparse pattern) having a line width of 100 nm and a pitch of 400 nm (line width: space width = 1: 3) in the first patterning process, the same photo is formed in the 2nd patterning process. The mask is translated by 200 nm in a direction perpendicular to the direction of the line, and a line-and-space pattern having a line width of 100 nm and a pitch of 400 nm (line width: space width = 1: 3) is formed. A line and space pattern (dense pattern) having a width of 100 nm and a pitch of 200 nm (line width: space width = 1: 1) can be formed.

As described above, in the 2nd patterning step, the resist pattern is formed in a region including the position where the resist pattern [1] is not formed, thereby forming the first resist pattern having fine and / or various shapes. Can do.
For example, as described above, when selective exposure is performed so as not to overlap the position where the resist pattern [1] is formed, the first resist pattern has a narrower pitch than the resist pattern [1] formed in the first patterning step. Can be formed.
In addition, a line and space pattern is formed in the first patterning process, and a line and space pattern in which the line and space pattern intersects with the line is formed in the 2nd patterning process. It is also possible to form a resist pattern. When performing cross-line patterning, the ratio of line width: space width and the crossing angle of each pattern in each line-and-space resist pattern match the shape of the finally obtained hole-shaped or lattice-shaped resist pattern. It may be appropriately controlled. For example, the intersecting angle may be made orthogonal or obliquely (less than 90 °) depending on the target pattern.
Therefore, in step (1), a first resist pattern is formed by a double patterning process, and then step (2) is performed, so that patterns of fine and / or various shapes are inverted compared to the case of single patterning. Obtained as a pattern.

<First positive resist composition>
The chemically amplified positive resist composition used as the first positive resist composition in the pattern forming method of the present invention is not particularly limited, and is selected from among many chemically amplified resist compositions that have been proposed so far. It can be appropriately selected and used. Examples of the chemically amplified resist composition include a base material component (A) having an acid dissociable, dissolution inhibiting group (hereinafter referred to as “component (A)”) and an acid generator component (B) that generates an acid upon exposure. Those containing (hereinafter referred to as component (B)) are common. In such a positive resist composition, when an acid is generated from the component (B) by exposure, the acid dissociable, dissolution inhibiting group of the component (A) is dissociated by the action of the acid, and Solubility increases. 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.

[(A) component]
The “base material component” is an organic compound having a film forming ability. As the substrate component, an organic compound having a molecular weight of 500 or more is preferably 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 non-polymer 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 1000 or more are usually used. Hereinafter, a polymer having a molecular weight of 1000 or more may be referred to as “resin”.
In the case of a polymer, the “molecular weight” is a polystyrene-reduced mass average molecular weight measured by GPC (gel permeation chromatography).
The component (A) may be a resin component (A1) (hereinafter also referred to as (A1) component) whose solubility in an alkali 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)) that increases the solubility in, or a mixture thereof.
In the present invention, the component (A) preferably contains the component (A1).
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 according to the type of exposure light source used when forming the resist pattern.
Specific examples of the base resin include those obtained by protecting the hydrophilic group of a resin having a hydrophilic group (hydroxyl group, carboxy group, etc.) with an acid dissociable, dissolution inhibiting group.
Examples of the resin having a hydrophilic group include a novolak resin, a resin having a structural unit derived from hydroxystyrene (PHS resin), such as polyhydroxystyrene (PHS) and hydroxystyrene-styrene copolymer, and an acrylic ester. An acrylic resin containing a structural unit derived from is mentioned. These may be used alone or in combination of two or more.

In the present specification and claims, the “structural unit derived from hydroxystyrene” is a structural unit formed by cleavage of an ethylenic double bond of hydroxystyrene.
“Hydroxystyrene” refers to hydroxystyrene in which a hydrogen atom is bonded to the α-position carbon atom (carbon atom to which the phenyl group is bonded), and a substituent (an atom or group other than a hydrogen atom) to the α-position carbon atom. ) Is also a concept including those that are combined. Examples of the substituent bonded to the α-position carbon atom include an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, and a hydroxyalkyl group.
“A structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid ester” is an acrylic acid ester in which a hydrogen atom is bonded to a carbon atom at the α-position (carbon atom to which the carbonyl group of acrylic acid is bonded), and a substituent (other than a hydrogen atom) on the carbon atom in the α-position In which the atoms or groups are bonded. Examples of the substituent bonded to the α-position carbon atom include an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, and a hydroxyalkyl group. The α-position carbon atom of the acrylate ester is a carbon atom to which the carbonyl group of acrylic acid is bonded unless otherwise specified.
In the hydroxystyrene or acrylate ester, the alkyl group as a substituent at the α-position is preferably a linear or branched alkyl group, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, n -Butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like can be mentioned.
Specific examples of the halogenated alkyl group as the substituent at the α-position include groups in which part or all of the hydrogen atoms of the above-mentioned “alkyl group as the substituent at the α-position” are substituted with a halogen atom. It is done. 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.
Specific examples of the hydroxyalkyl group as a substituent at the α-position include a group in which part or all of the hydrogen atoms of the “alkyl group as the substituent at the α-position” are substituted with a hydroxyl group. 1-5 are preferable and, as for the number of the hydroxyl groups in this hydroxyalkyl group, 1 is the most preferable.
In the present invention, the hydrogen atom, the alkyl group having 1 to 5 carbon atoms or the halogenated alkyl group having 1 to 5 carbon atoms is preferably bonded to the α-position of hydroxystyrene or acrylate ester. An alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is more preferable, and a hydrogen atom or a methyl group is most preferable in terms of industrial availability.

The component (A1) in the positive resist composition used in the present invention preferably contains a structural unit derived from an acrylate ester.
As the component (A1), a resin component (A1-1) having a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group (hereinafter referred to as component (A1-1)). ) Is preferred.
In addition to the structural unit (a1), the component (A1-1) further includes a structural unit derived from an acrylate ester containing a lactone-containing cyclic group and an acrylic acid containing a —SO ₂ -containing cyclic group It is preferable to have at least one structural unit (a2) selected from the group consisting of structural units derived from esters.
The component (A1-1) is derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group, in addition to the structural unit (a1) or in addition to the structural units (a1) and (a2). It is preferable to have a structural unit (a3).

-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 (A1-1) difficult to dissolve in an alkali developer before dissociation, and is exposed from the (B) component by exposure. It is dissociated by the action of the generated acid to increase the solubility of the entire component (A1-1) in an alkali developer.
As the acid dissociable, dissolution inhibiting group in the structural unit (a1), 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.
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) —O— ), The tertiary carbon atom of the chain or cyclic alkyl group is bonded to the terminal oxygen atom. 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 in the “acid dissociable, dissolution inhibiting group containing an 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, 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.
The aliphatic cyclic group is preferably a polycyclic group.
Examples of the aliphatic cyclic group include one or more monocycloalkanes 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 a bicycloalkane, tricycloalkane, tetracycloalkane, or the like. 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.
Examples of the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group include:
(I) Substitution with a carbon atom bonded to an atom adjacent to the acid dissociable, dissolution inhibiting group (for example, —O— in —C (═O) —O—) on the ring skeleton of a monovalent aliphatic cyclic group A group in which a group (atom or group other than a hydrogen atom) is bonded to form a tertiary carbon atom;
(Ii) a group having a monovalent aliphatic cyclic group and a branched alkylene having a tertiary carbon atom bonded thereto; and the like.
In the group (i), examples of the substituent bonded to the carbon atom bonded to the atom adjacent to the acid dissociable, dissolution inhibiting group on the ring skeleton of the aliphatic cyclic group include an alkyl group. Examples of the alkyl group include those similar to R ¹⁴ in formulas (1-1) to (1-9) described later.
Specific examples of the group (i) include groups represented by the following general formulas (1-1) to (1-9).
Specific examples of the group (ii) include groups represented by the following general formulas (2-1) to (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 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).

[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 for R ¹ ′ and R ² ′ include the same alkyl groups as those described above for the α-position substituent in the description of the acrylic ester, and a methyl group or an ethyl group is preferable. Is most preferred.
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 as the α-position substituent in the description of the acrylic ester.
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 the aliphatic cyclic groups mentioned in “Acid dissociable, dissolution inhibiting group containing a 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.

  More specifically, examples of the structural unit (a1) include structural units represented by general formula (a1-0-1) shown below, structural units represented by general formula (a1-0-2) shown below, and the like. .

［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；Ｘ^１は酸解離性溶解抑制基であり；Ｙ^２は２価の連結基であり；Ｘ^２は酸解離性溶解抑制基である。］

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; X ¹ is an acid dissociable, dissolution inhibiting group; Y ² is a divalent linkage. X ² is an acid dissociable, dissolution inhibiting group. ]

In general formula (a1-0-1), the alkyl group and halogenated alkyl group represented by R are the same as the alkyl group and halogenated alkyl group mentioned as the substituent at the α-position in the description of the acrylate ester, respectively. Can be mentioned. R is 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 most preferably a hydrogen atom or a methyl group.
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).
The divalent linking group for Y ² is not particularly limited, and examples thereof include an alkylene group, a divalent aliphatic cyclic group, a divalent aromatic cyclic group, and a divalent linking group containing a hetero atom. It is done.
When Y ² is an alkylene group, it is preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms, and 1 to 3 carbon atoms. Most preferably it is.
When Y ² is a divalent aliphatic cyclic group, the aliphatic cyclic group is the above-mentioned “acid containing an aliphatic cyclic group” except that it is a group in which two or more hydrogen atoms have been removed. Examples thereof include the same aliphatic cyclic groups as mentioned in the “Dissociable dissolution inhibiting group”. As the aliphatic cyclic group for Y ^2, a group in which two or more hydrogen atoms have been removed from cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane or tetracyclododecane is particularly preferable.
When Y ² is a divalent aromatic cyclic group, examples of the aromatic cyclic group include groups in which two hydrogen atoms have been removed from an optionally substituted aromatic hydrocarbon ring. It is done. The aromatic hydrocarbon ring preferably has 6 to 15 carbon atoms, and examples thereof include a benzene ring, a naphthalene ring, a phenanthrene ring, and an anthracene ring. Among these, a benzene ring or a naphthalene ring is particularly preferable.
Examples of the substituent that the aromatic hydrocarbon ring may have include a halogen atom, an alkyl group, an alkoxy group, a halogenated lower alkyl group, and an oxygen atom (═O). Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom.

When Y ² is a divalent linking group containing a hetero atom, examples of the divalent linking group containing a hetero 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 or an acyl group), —S—. , —S (═O) ₂ —, —S (═O) ₂ —O—, a group represented by the formula —A—O—B—, and a formula —A—O—C (═O) —B—. And a group represented by the formula — [A—C (═O) —O] _m —B—, and the like. Here, in formulas -A-O-B-, -A-O-C (= O) -B-, or-[A-C (= O) -O] _m -B-, A and B are each independently The divalent hydrocarbon group which may have a substituent, -O- is an oxygen atom, and m is an integer of 0-3.
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.

When Y ² is —A—O—B—, —A—O—C (═O) —B— or — [A—C (═O) —O] _m —B—, A and B are Each is independently a divalent hydrocarbon group which may have a substituent. The hydrocarbon group having “substituent” means that part or all of the hydrogen atoms in the hydrocarbon group are substituted with groups or atoms other than hydrogen atoms.
The hydrocarbon group in A 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 for A may be saturated or unsaturated, and is usually preferably saturated.
Specific examples of the aliphatic hydrocarbon group for A include a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in the structure.
The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, still more preferably 2 to 5, and most preferably 2.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group, an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [— (CH ₂ ) ₃ -], tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ] , and the like.
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 - 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 —; Alkyl trimethylene groups such as —CH (CH ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) CH ₂ —; —CH (CH ₃ ) CH ₂ CH ₂ CH ₂ —, —CH ₂ CH (CH _{3) CH} 2 CH ₂ - alkyl, such as alkyl tetramethylene group such as Such as an alkylene group, and the like. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
These linear or branched aliphatic hydrocarbon groups 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 include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), Examples include a group bonded to the terminal of an aromatic hydrocarbon group or interposed in the middle of a 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. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, tetra And cyclododecane.
The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.

As A, a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 1 to 5 carbon atoms is more preferable, and a methylene group or an ethylene group is particularly preferable. .
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 — [A—C (═O) —O] _m —B—, m is an integer of 0 to 3, preferably an integer of 0 to 2, and 0 or 1 Is more preferable and 1 is most preferable.

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

［式中、Ｒ、Ｒ^１’、Ｒ^２’、ｎ、ＹおよびＹ^２はそれぞれ前記と同じであり、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す。］

[Wherein, R, R ¹ ′, R ² ′, n, Y and Y ² are the same as defined above, and X ′ represents a tertiary alkyl ester-type acid dissociable, dissolution inhibiting group. ]

In the formula, X ′ is the same as the tertiary alkyl ester type acid dissociable, dissolution inhibiting group.
^{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 (a1) is preferably a structural unit represented by the general formula (a1-1) or (a1-3), specifically, the formulas (a1-1-1) to (a1). -1-4), (a1-1-20) to (a1-1-23), and (a1-3-25) to (a1-3-32). More preferably, at least one kind is used.
Further, the structural unit (a1) is represented by the following general formula (a1-1-01) including the structural units represented by the formulas (a1-1-1) to (a1-1-3). , Formulas (a1-1-16) to (a1-1-17), (a1-1-20) to (a1-1-23), 02), those represented by the following general formula (a1-3-01) including the structural units represented by formulas (a1-3-25) to (a1-3-26), and formulas What is represented by the following general formula (a1-3-02) including the structural units represented by (a1-3-27) to (a1-3-28), formulas (a1-3-29) to ( What represented by the following general formula (a1-3-03) which includes the structural unit of a1-3-32) is preferable.

［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を示し、Ｒ^１１は炭素数１〜５のアルキル基を示し、Ｒ^１２は炭素数１〜５のアルキル基を示し、ｈは１〜６の整数を示す。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, R ¹¹ represents an alkyl group having 1 to 5 carbon atoms, and R ¹² represents a carbon number. 1 to 5 represents an alkyl group, and h represents an integer of 1 to 6. ]

In general formula (a1-1-01), R is the same as defined above.
Examples of the alkyl group for R ¹¹ include the same alkyl groups as those described above for R, and a methyl group, an ethyl group, or an isopropyl group is preferable.
In general formula (a1-1-02), R is the same as defined above.
Examples of the alkyl group for R ¹² include the same alkyl groups as those described above for R, and a methyl group, an ethyl group, or an isopropyl group is preferable.
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炭素数１〜５の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 having 1 to 5 carbon atoms; R ¹⁴ represents an alkyl group having 1 to 5 carbon atoms, and R ¹³ represents a hydrogen atom. Or it is a methyl group, a is an integer of 1-10, n 'is an integer of 1-6. ]

In formula (a1-3-01) or (a1-3-02), R is the same as described above.
R ¹³ is preferably a hydrogen atom.
Alkyl group for R ¹⁴ is the formula (1-1) is the same as ^{R 14} in - (1-9), a methyl group, an ethyl group or an isopropyl group.
a is preferably an integer of 1 to 8, more preferably an integer of 2 to 5, and most preferably 2.
n ′ is most preferably 1 or 2.

［式中、Ｒは前記と同じであり、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、Ｘ’は酸解離性溶解抑制基であり、ｎは０〜３の整数である。］

[Wherein, R is the same as defined above, Y ² ′ and Y ² ″ each independently represent a divalent linking group, X ′ represents an acid dissociable, dissolution inhibiting group, and n represents 0 to 3] It is an integer.]

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 in formula (a1-3).
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 and an ethylene group are 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 in X ′ include the same groups as described above, and are preferably tertiary alkyl ester type acid dissociable, dissolution inhibiting groups, and (i) the monovalent aliphatic cyclic group described above. A group having a tertiary carbon atom on the ring skeleton of the group is more preferable, and among them, the group represented by the general formula (1-1) is preferable.
n is an integer of 0 to 3, and n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 1.

  In the component (A1-1), the proportion of the structural unit (a1) is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, based on all the structural units constituting the component (A1-1). 25-50 mol% is more preferable. 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.

Structural unit (a2):
The structural unit (a2) is composed of a structural unit derived from an acrylate ester containing a lactone-containing cyclic group (hereinafter referred to as the structural unit (a2 ^L )) and an acrylate ester containing an —SO ₂ -containing cyclic group. It is at least one type of structural unit selected from the group consisting of derived structural units (hereinafter referred to as structural unit (a2 ^S )).

-Structural unit (a2 ^L ):
The structural unit (a2 ^L ) 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 lactone cyclic group of the structural unit (a2 ^L ) is used to form a resist film, the component (A1-1) can be used to increase the adhesion of the resist film to the substrate or to a developer containing water. It is effective in increasing affinity.
The lactone cyclic group in the structural unit (a2 ^L ) is not particularly limited, and any one can be used. Specifically, as the lactone-containing monocyclic group, a group in which one hydrogen atom is removed from a 4- to 6-membered ring lactone, for example, a group in which one hydrogen atom is removed 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 ^L ) 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.
A ″ is preferably an alkylene group having 1 to 5 carbon atoms, an oxygen atom (—O—) or a sulfur atom (—S—), more preferably an alkylene group having 1 to 5 carbon atoms or —O—. 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. Examples of the divalent linking group include the same divalent linking groups as those described for Y ² in formula (a1-0-2). 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, in the description of Y ² , the same as the linear alkylene group and branched alkylene group mentioned as the aliphatic hydrocarbon group for A 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 carbon atoms, and still more preferably 1 to 5 carbon atoms.
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.

-Structural unit (a2 ^S ):
The structural unit (a2 ^S ) is a structural unit derived from an acrylate ester containing a —SO ₂ -containing cyclic group.
Here, -SO ₂ - and containing cyclic group, -SO ₂ - within the ring skeleton thereof shows a cyclic group containing a ring containing, in particular, -SO ₂ - in the sulfur atom (S) Are cyclic groups that form part of the ring skeleton of the cyclic group. A ring containing —SO ₂ — in the ring skeleton is counted as one ring, and if it is only the ring, it is a monocyclic group, and if it has another ring structure, it is polycyclic regardless of the structure It is called a group. The —SO ₂ — containing cyclic group may be monocyclic or polycyclic.
-SO ₂ - containing cyclic group, in particular, -O-SO ₂ - within the ring skeleton cyclic group containing, i.e. -O-SO ₂ - -O-S- medium is a part of the ring skeleton A cyclic group containing a sultone ring to be formed is preferable.
The —SO ₂ — containing cyclic group preferably has 3 to 30 carbon atoms, preferably 4 to 20 carbon atoms, more preferably 4 to 15 carbon atoms, and particularly preferably 4 to 12 carbon atoms. . However, the carbon number is the number of carbon atoms constituting the ring skeleton, and does not include the carbon number in the substituent.
The —SO ₂ — containing cyclic group may be an —SO ₂ — containing aliphatic cyclic group or an —SO ₂ — containing aromatic cyclic group. Preferably -SO ₂ - containing aliphatic cyclic group.
The —SO ₂ -containing aliphatic cyclic group includes at least a hydrogen atom from an aliphatic hydrocarbon ring in which a part of carbon atoms constituting the ring skeleton is substituted with —SO ₂ — or —O—SO ₂ —. One group is excluded. More specifically, a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring in which —CH ₂ — constituting the ring skeleton is substituted with —SO ₂ —, —CH ₂ — constituting the ring And a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring in which CH ₂ — is substituted with —O—SO ₂ —.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms are removed from a monocycloalkane having 3 to 6 carbon atoms. Examples of the monocycloalkane include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon group, a group in which two hydrogen atoms have been removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane. , Tricyclodecane, tetracyclododecane and the like.

The —SO ₂ — containing cyclic group may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), —COOR ⁰⁶ , —OC (═O) R ⁰⁶ , a hydroxyalkyl group, a cyano group, and the like. Is mentioned.
The alkyl group as the substituent is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. 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, a neopentyl group, and a hexyl group. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the group couple | bonded with the oxygen atom (-O-) to the alkyl group quoted as the alkyl group as the said substituent is mentioned.
Examples of the halogen atom as the substituent 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 for the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.
Examples of the halogenated alkyl group as the substituent include groups in which part or all of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the substituent are substituted with the halogen atom. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.
The ^-COOR 06, ^{R 06} in the -OC (= ^{O) R 06} are both hydrogen atom or a C 1-15 linear, branched or cyclic alkyl group.
When R ⁰⁶ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. preferable.
When R ⁰⁶ 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, 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. More 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. .
The hydroxyalkyl group as the substituent is preferably one having 1 to 6 carbon atoms. Specifically, at least one of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the substituent is substituted with a hydroxyl group. Group.
More specifically, examples of the —SO ₂ -containing cyclic group include groups represented by the following general formulas (3-1) to (3-4).

［式中、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、ｚは０〜２の整数であり、Ｒ^６はアルキル基、アルコキシ基、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ^０６、−ＯＣ（＝Ｏ）Ｒ^０６、ヒドロキシアルキル基またはシアノ基であり、Ｒ^０６は水素原子またはアルキル基である。］

[In the formula, 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, z is an integer of 0 to 2, and R ⁶ is an alkyl group. , An alkoxy group, a halogenated alkyl group, a hydroxyl group, —COOR ⁰⁶ , —OC (═O) R ⁰⁶ , a hydroxyalkyl group or a cyano group, and R ⁰⁶ is a hydrogen atom or an alkyl group. ]

In the general formulas (3-1) to (3-4), A ′ represents an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (—O—) or a sulfur atom (—S—), An oxygen atom or a sulfur atom.
The alkylene group having 1 to 5 carbon atoms in A ′ is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group.
When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which —O— or —S— is interposed between the terminal or carbon atoms of the alkylene group, such as —O—CH _{2. -, - CH 2 -O-CH} 2 -, - S-CH 2 -, - CH 2 -S-CH 2 - , and the like.
A ′ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.
z may be any of 0 to 2, and is most preferably 0.
When z is 2, the plurality of R ⁶ may be the same or different.
The alkyl group in R ^6, an alkoxy group, a halogenated alkyl ^{group, -COOR 06, -OC (= O} ) R 06, examples of the hydroxyalkyl group, respectively, wherein in -SO ₂ - have the containing cyclic group And the same alkyl groups, alkoxy groups, halogenated alkyl groups, —COOR ⁰⁶ , —OC (═O) R ⁰⁶ , and hydroxyalkyl groups as those exemplified as the preferred substituents.
Below, the specific cyclic group represented by the said general formula (3-1)-(3-4) is illustrated. In the formula, “Ac” represents an acetyl group.

Among the above, the —SO ₂ -containing cyclic group is preferably a group represented by the general formula (3-1), and the chemical formulas (3-1-1), (3-1-18), ( It is more preferable to use at least one selected from the group consisting of groups represented by any of 3-3-1) and (3-4-1), and represented by the chemical formula (3-1-1). Are most preferred.

More specifically, examples of the structural unit (a2 ^S ) include structural units represented by general formula (a2-6) 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^５は−ＳＯ_２−含有環式基であり、Ｒ^２９は単結合または２価の連結基である。］

[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 ⁵ is an —SO ₂ -containing cyclic group, and R ²⁹ is a single bond] Or it is a bivalent coupling group. ]

In formula (a2-6), R is the same as defined above.
R ⁵ is the same as the —SO ₂ — containing cyclic group mentioned above.
R ²⁹ may be a single bond or a divalent linking group. Since it is excellent in the effect of this invention, it is preferable that it is a bivalent coupling group.
Examples of the divalent linking group for R ^29, the formula (a2-1) ~ (a2-5) of the same divalent linking groups as those exemplified in the description of ^{R 29} in can be listed. Among these, those containing an alkylene group or an ester bond (—C (═O) —O—) are preferable.
The alkylene group is 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 Y ² can be used.
As the divalent linking group containing an ester bond, in particular, the general formula: —R ⁴ —C (═O) —O— [wherein R ⁴ is a divalent linking group. ] Is preferable. That is, the structural unit (a2 ^S ) is preferably a structural unit represented by the following general formula (a2-6-1).

［式中、ＲおよびＲ^５はそれぞれ前記と同様であり、Ｒ^４は２価の連結基である。］

[Wherein, R and R ⁵ are the same as defined above, and R ⁴ is a divalent linking group. ]

R ⁴ is not particularly limited, and for example, the same as the divalent linking group for Y ² in the general formula (a1-0-2) mentioned in the description of the structural unit (a1). Things.
The divalent linking group for R ⁴ is preferably a linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent linking group containing a hetero atom.
Examples of the linear or branched alkylene group, divalent alicyclic hydrocarbon group, and divalent linking group containing a hetero atom include the linear or branched groups mentioned above as preferred for Y ^2. Examples thereof include the same chain alkylene groups, divalent alicyclic hydrocarbon groups, and divalent linking groups containing a hetero atom.
Among these, a linear or branched alkylene group or a divalent linking group containing an oxygen atom as a hetero atom is preferable.
As the linear alkylene group, a methylene group or an ethylene group is preferable, and a methylene group is particularly preferable.
As the branched alkylene group, an alkylmethylene group or an alkylethylene group is preferable, and —CH (CH ₃ ) —, —C (CH ₃ ) ₂ — or —C (CH ₃ ) ₂ CH ₂ — is particularly preferable.
The divalent linking group containing an oxygen atom is preferably a divalent linking group containing an ether bond or an ester bond, and the above formulas -A-O-B-, -A-O-C (= O) -B- Or the group represented by-[AC (= O) -O] _m- B- is more preferable.
Among them, preferred is a group represented by the formula -A-O-C (= O ) -B-, - represented by _{- (CH 2) c -C (} = O) -O- (CH 2) d The group is particularly preferred. c is an integer of 1 to 5, and 1 or 2 is preferable. d is an integer of 1-5, and 1 or 2 is preferable.

As the structural unit (a2 ^S ), a structural unit represented by general formula (a2-6-11) or (a2-6-12) shown below is particularly desirable, and represented by formula (a2-6-12) A structural unit is more preferable.

［式中、Ｒ、Ａ’、Ｒ^６、ｚおよびＲ^４はそれぞれ前記と同じである。］

[Wherein, R, A ′, R ⁶ , z and R ⁴ are the same as defined above. ]

In formula (a2-6-11), A ′ is preferably a methylene group, an oxygen atom (—O—) or a sulfur atom (—S—).
R ⁴ is preferably a linear or branched alkylene group or a divalent linking group containing an oxygen atom. As the linear or branched alkylene group and the divalent linking group containing an oxygen atom in R ^4, the linear or branched alkylene group mentioned above and a divalent linking group containing an oxygen atom are mentioned. Examples are the same as the linking group.
As the structural unit represented by the formula (a2-6-12), a structural unit represented by general formula (a2-6-12a) or (a2-6-12b) shown below is particularly desirable.

［式中、ＲおよびＡ’はそれぞれ前記と同じであり、ｃ〜ｅはそれぞれ独立に１〜３の整数である。］

[Wherein, R and A ′ are the same as defined above, and c to e are each independently an integer of 1 to 3.] ]

In the component (A1-1), as the structural unit (a2), one type may be used alone, or two or more types may be used in combination. For example, as the structural unit (a2), only the structural unit (a2 ^S ) may be used, or only the structural unit (a2 ^L ) may be used, or they may be used in combination. As the structural unit (a2 ^S ) or the structural unit (a2 ^L ), one type may be used alone, or two or more types may be used in combination.
As the structural unit (a2), at least one selected from the group consisting of structural units represented by the general formulas (a2-1) to (a2-6) is preferable, and the general formulas (a2-1) to ( At least one selected from the group consisting of structural units represented by a2-3) and (a2-6) is more preferred. Among them, chemical formulas (a2-1-1), (a2-2-1), (a2-2-7), (a2-3-1), (a2-3-5) or (a2-6-1) And at least one selected from the group consisting of structural units represented by
In the component (A1-1), the proportion of the structural unit (a2) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, based on the total of all the structural units constituting the component (A1-1). Preferably, 20-50 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.

-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 (A1-1) has the structural unit (a3), the hydrophilicity of the component (A) is increased, the affinity with the developer is increased, the alkali solubility in the exposed area is improved, and the resolution is increased. Contributes to the improvement of sex.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a fluorinated alcohol group (a hydroxyalkyl group in which a part of the hydrogen atoms of the alkyl group is substituted with a fluorine atom). A hydroxyl group is particularly preferable.
In the structural unit (a3), the number of polar groups bonded to the aliphatic hydrocarbon group is not particularly limited, but is preferably 1 to 3, and most preferably 1.
Examples of the aliphatic hydrocarbon group to which the polar group is bonded include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group), a polycyclic aliphatic hydrocarbon group (multiple Cyclic group). 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.
The structural unit (a3) is preferably a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyl group, a cyano group, a carboxy group or a fluorinated alcohol group. 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.

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 (a3) is derived from hydroxyethyl ester of acrylic acid. Are preferred.
When the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a polycyclic group, the structural unit (a3) is a structural unit represented by the following formula (a3-1), a general formula (a3-2) ), A structural unit represented by the general formula (a3-3), and the like are preferable. Especially, the structural unit represented by general formula (a3-1) is preferable.

（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 the same as 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.
In the component (A1-1), the proportion of the structural unit (a3) is preferably 5 to 50 mol%, and 5 to 40 mol% with respect to all the structural units constituting the component (A1-1). More preferably, 5-25 mol% is further more preferable.

The component (A1-1) may contain other structural units other than the structural units (a1) to (a3) as long as the effects of the present invention are not impaired.
The other structural units are not particularly limited as long as they are other structural units not classified into the structural units (a1) to (a3) described above, and are for ArF excimer laser and KrF excimer laser (preferably ArF excimer). A number of hitherto known materials can be used for resist resins such as lasers.
Examples of the other structural unit include a structural unit (a4) derived from an acrylate ester containing a non-acid-dissociable aliphatic polycyclic group, and a structural unit mentioned in the description of the component (A ′) described later ( a5 ′) and the like. However, in the present invention, the organic solvent for dissolving each component of the first positive resist composition is at least one selected from the group consisting of alcohol solvents, fluorine solvents, and ether organic solvents having no hydroxyl group. In the case where is not used, the component (A1-1) preferably has no structural unit (a5 ′). On the other hand, when using at least one selected from the group consisting of an alcohol-based solvent, a fluorine-based solvent, and an ether-based organic solvent having no hydroxyl group as an organic solvent for dissolving each component of the first positive resist composition The component (A1-1) preferably has a structural unit (a5 ′) from the viewpoint of solubility in these organic solvents.

Examples of the aliphatic polycyclic group in the structural unit (a4) include those similar to those exemplified in the case of the structural unit (a1). For the ArF excimer laser and the KrF excimer laser ( A number of hitherto known materials can be used as the resin component of the resist composition (preferably for ArF excimer laser). 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。）

(In the formula, R is as defined above.)

  When the structural unit (a4) is contained in the component (A1-1), the structural unit (a4) is contained in an amount of 1 to 30 mol% based on the total of all the structural units constituting the component (A1-1). It is preferable that 10 to 20 mol% is contained.

The component (A1-1) 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.
In the component (A1-1), the total ratio of the structural units derived from the acrylate ester (the structural units (a1) to (a4), (a5 ′), etc.) constitutes the component (A1-1). 50 mol% or more is preferable with respect to the total of all the structural units, 80 mol% or more is more preferable, and 100 mol% may be sufficient.
In the component (A), as the component (A1-1), one type may be used alone, or two or more types may be used in combination.

In addition to the component (A1-1), as a preferable component (A1), a structural unit (a11) derived from hydroxystyrene, a structural unit derived from an acrylate ester having an acid dissociable, dissolution inhibiting group, and At least one component selected from the group consisting of a structural unit derived from hydroxystyrene and having at least one hydrogen atom of a hydroxyl group in the structural unit substituted with an acid dissociable, dissolution inhibiting group-containing group And a resin component (A1-2) having a unit (a12) (hereinafter referred to as (A1-2) component).
The component (A1-2) preferably further has a structural unit (a13) derived from styrene.

Structural unit (a11):
The structural unit (a11) is a structural unit derived from hydroxystyrene.
As described above, “a structural unit derived from hydroxystyrene” means a structural unit formed by cleavage of an ethylenic double bond of hydroxystyrene, and “hydroxystyrene” means a carbon atom at the α-position. In addition to hydroxystyrene in which a hydrogen atom is bonded to (the carbon atom to which the phenyl group is bonded), those in which a substituent (atom or group other than a hydrogen atom) is bonded to the α-position carbon atom are also included. Examples of the substituent bonded to the α-position carbon atom include an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, and a hydroxyalkyl group. Among these, an alkyl group is preferable.
Hereinafter, hydroxystyrene in which a hydrogen atom is bonded to the α-position carbon atom is referred to as unsubstituted hydroxystyrene, and one in which a substituent is bonded to the α-position carbon atom is referred to as α-substituted hydroxystyrene. If there is no particular limitation, the “hydroxystyrene” may be either unsubstituted hydroxystyrene or α-substituted hydroxystyrene.
Hydroxystyrene may have a substituent bonded to its benzene ring. Examples of the substituent include a halogen atom, an alkyl group having 1 to 5 carbon atoms, and a halogenated alkyl group having 1 to 5 carbon atoms.
Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
Examples of the alkyl group as a substituent include the same as the alkyl group for R ¹ .
Examples of the halogenated alkyl group as a substituent include a group in which part or all of the hydrogen atoms in the alkyl group as the substituent are substituted with a halogen atom. The halogen atom includes a halogen atom as the substituent. The thing similar to what was mentioned as an atom is mentioned. The halogenated alkyl group is preferably a fluorinated alkyl group.
Preferred examples of the structural unit (a11) include structural units represented by general formula (a11-1) shown below.

［式中、Ｒ^０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。］

[Wherein, R ⁰ 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 a halogenated alkyl group 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 (a11-1), R ⁰ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.
Examples of the alkyl group for R ⁰ include the same alkyl groups as those described above for the substituent bonded to the α-position carbon atom in the description of hydroxystyrene.
R ⁰ is particularly preferably a hydrogen atom or a methyl group.
Examples of R ⁶ ′ include the same groups as those described above as the substituent that may be bonded to the benzene ring of hydroxystyrene.
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 (a11-1), 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 ⁶ ′ 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 ⁶ ′ may be the same or different.

As the structural unit (a11), one type may be used alone, or two or more types may be used in combination.
In the component (A1-2), the proportion of the structural unit (a11) is preferably 50 to 90 mol% with respect to the total of all the structural units constituting the component (A1-2), and is 55 to 85 mol%. More preferably. When it is at least the lower limit of the range, moderate alkali solubility is obtained, and the effect of containing the structural unit (a11) is sufficiently obtained. When the amount is not more than the upper limit of the range, the balance with other structural units is good.

-Structural unit (a12):
The structural unit (a12) is a structural unit derived from an acrylate ester having a dissociable dissolution inhibiting group (hereinafter referred to as a structural unit (a12 ^A )) and a structural unit derived from hydroxystyrene. At least one structural unit selected from the group consisting of structural units in which at least one of the hydrogen atoms of the hydroxyl group is substituted with an acid dissociable, dissolution inhibiting group-containing group (hereinafter referred to as structural unit (a12 ^H )). is there.
As the structural unit (a12 ^A ), the same structural units as the structural unit (a1) can be mentioned.
Examples of the structural unit (a12 ^H ) include those in which the hydrogen atom of the hydroxyl group in the general formula (a11-1) is substituted with an acid dissociable, dissolution inhibiting group-containing group.

The acid-dissociable, dissolution-inhibiting group-containing group in the structural unit (a12 ^H ) may be composed only of an acid-dissociable, dissolution-inhibiting group, or is composed of an acid-dissociable, dissolution-inhibiting group and other groups or atoms. It may be. Specific examples of the latter include an organic group composed of an acid dissociable, dissolution inhibiting group and a divalent linking group bonded to the acid dissociable, dissolution inhibiting group. The divalent linking group is not particularly limited, and examples thereof include the divalent linking group in Y ² in the general formula (a1-0-2) mentioned in the description of the structural unit (a1). The thing similar to a thing is mentioned.
The acid dissociable, dissolution inhibiting group-containing group is not particularly limited, and can be appropriately selected from those proposed in many resins for resist compositions such as for KrF excimer laser and ArF excimer laser. Examples thereof are the same as those mentioned in the structural unit (a1), such as tertiary alkyl ester type acid dissociable, dissolution inhibiting groups, acetal type acid dissociable, dissolution inhibiting groups, and the like. In the structural unit (a12 ^H ), examples of the acid dissociable, dissolution inhibiting group for substituting a hydrogen atom of the hydroxyl group of hydroxystyrene include a tertiary alkyl group and a group (7-2) in the group (7-1) shown below. Is preferred.
In addition, as an acid dissociable, dissolution inhibiting group-containing group consisting of an acid dissociable, dissolution inhibiting group and other groups or atoms, specifically, the following group (7-1) (however, a tertiary alkyl group is excluded) ), (7-3) and the like.
However, the present invention is not limited to this, and any acid dissociable, dissolution inhibiting group-containing group not classified into groups (7-1) to (7-4) can be used.

Group (7-1):
Group (7-1) is a tertiary alkyl group-containing group.
“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. .
The “other atom or group other than the tertiary alkyl group” constituting the tertiary alkyl group-containing group together with the tertiary alkyl group includes a carbonyloxy group, a carbonyl group, an alkylene group, an oxygen atom (—O— ) And the like.

Examples of the tertiary alkyl group-containing group in Z 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 groups represented by general formula (7-1a) shown below.

In formula (7-1a), R ^{7f to} R ^7g 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.
The total carbon number of the group represented by the general formula (7-1a) is preferably 4 to 7, more preferably 4 to 6, and most preferably 4 to 5.
Preferred examples of the group represented by the general formula (7-1a) 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 further preferably an alkylene group having 2 to 2 carbon atoms.

As the chain-like tertiary alkyloxycarbonyl group, for example, a group represented by general formula (7-1b) shown below can be mentioned.
^R 7f ^{to R 7 g} in the formula (7-1b) is the same as ^R 7f ^{to R 7 g} in the formula (7-1a).
The chain-like tertiary alkyloxycarbonyl group is preferably a tert-butyloxycarbonyl group (t-boc) or a tert-pentyloxycarbonyl group.

Examples of the chain-like tertiary alkyloxycarbonylalkyl group include a group represented by general formula (7-1c) shown below.
^R 7f ^{to R 7 g} in the formula (7-1C) is the same as ^R 7f ^{to R 7 g} in the formula (7-1a).
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 and a tert-butyloxycarbonylethyl group are 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. A tert-butyloxycarbonyl group (t-boc) is most preferred.

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, 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 [1] or [2] group as the 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. .
Examples of the group [1] include a 2-methyl-2-adamantyl group, a 2-ethyl-2-adamantyl group, a 1-methyl-1-cycloalkyl group, and a 1-ethyl-1-cycloalkyl group. .
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 lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (═O), and the like.
Examples of the group [2] include a group represented by the following chemical formula (7-1d).

In formula (7-3b), R ^7k is a cycloalkyl group that 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 ^7j and R ^7m are each independently a linear or branched alkyl group. As this alkyl group, the same thing as the alkyl group of R < ^7f > -R < ^7g > in said Formula (7-1a) is mentioned.

The tertiary alkyl group-containing group having a cyclic structure includes a tertiary alkyl group composed of the group [1] or [2] described above; a group [1] or [2] described above as a tertiary alkyl group; A tertiary alkyloxycarbonylalkyl group having the above-mentioned group [1] or [2] as the tertiary alkyl group.
Examples of the tertiary alkyloxycarbonyl group and the tertiary alkyloxycarbonylalkyl group include —C (R ^7f ) (R ^7g ) (R in the general formulas (7-1b) and (7-1c), respectively. ^7h ) is substituted with the group [1] or [2].

  As the group (7-1), a chain-like tertiary alkyloxycarbonyl group is preferable from the viewpoint of excellent resist pattern shape, lithography properties (depth of focus (DOF), etc.), and the general formula (7-1a). ) Is more preferred, and tert-butyloxycarbonyl group (t-boc group) is most preferred.

Group (7-2):
Group (7-2) is an alkoxyalkyl group.
Examples of the alkoxyalkyl group include groups represented by general formula (7-2a) shown below.

［式（７−１ａ）中、Ｒ^７ａは直鎖状または分岐鎖状のアルキレン基であり、Ｒ^７ｂ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のアルキル基である。］

[In the formula (7-1a), R ^7a is a linear or branched alkylene group, R ^7b is an aliphatic cyclic group, an aromatic cyclic hydrocarbon group or an alkyl group having 1 to 5 carbon atoms. It is. ]

In the general formula (7-1a), R ^7a is a linear or branched alkylene group. The alkylene group preferably has 1 to 15 carbon atoms, more preferably 1 to 5 carbon atoms, still more preferably 1 to 3 carbon atoms, and particularly preferably 1 to 2 carbon atoms.
R ^7b is an aliphatic cyclic group, an aromatic cyclic hydrocarbon group, or an alkyl group having 1 to 5 carbon atoms.
The “aliphatic cyclic group” means a monocyclic group or polycyclic group having no aromaticity, and may be either saturated or unsaturated, and is preferably saturated.
The aliphatic cyclic group for R ^7b is a monovalent aliphatic cyclic group. As the aliphatic cyclic group, for example, it can be appropriately selected from 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 tetracyclododecyl group are industrially preferable, and an adamantyl group is particularly preferable.
Examples of the aromatic cyclic hydrocarbon group for R ^7b 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.
As the alkyl group for R ^7b, the same alkyl groups as those described above for R ^{0 in} formula (a11-1) can be used, and a methyl group or an ethyl group is more preferable, and an ethyl group is the most preferable.
As the group (7-2), a group represented by general formula (7-2b) shown below is particularly desirable.

［式（７−１ｂ）中、Ｒ^７ｂは前記と同じであり、Ｒ^７ｃは水素原子もしくは炭素数１〜５のアルキル基であり、または、Ｒ^７ｂおよびＲ^７ｃがそれぞれ独立に炭素数１〜５のアルキレン基であって、Ｒ^７ｂとＲ^７ｃとが結合していてもよく、Ｒ^７ｄは水素原子または炭素数１〜５のアルキル基である。］

[In Formula (7-1b), R ^7b is the same as defined above, R ^7c is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, or R ^7b and R ^7c each independently represent 1 to 5 is an alkylene group, and R ^7b and R ^7c may be bonded to each other, and R ^7d is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ]

In the formula ^(7-2b), as the ^{R 7b,} the same as ^{R 7b} of the general formula (7-2a) can be mentioned.
As the alkyl group for R ^7c, the same alkyl groups as those described above for R ^{0 in} formula (a11-1) can be used. Industrially, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
R ^7d is an alkyl group or a hydrogen atom. As the alkyl group for R ^7d, the same alkyl groups as those for R ^7c can be used. R ^7d is preferably a hydrogen atom industrially.
In formula (7-1b), since the resist pattern shape and the like are excellent, it is preferable that R ^7c is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ^7d is a hydrogen atom. In particular, it is preferable that R ^7c is a methyl group and R ^7d is a hydrogen atom.
In Formula (7-1b), R ^7b and R ^7c are each independently an alkylene group having 1 to 5 carbon atoms, and R ^7b and R ^7c may be bonded to each other. In this case, in the general formula (7-1b), a cyclic group is formed by R ^7c , R ^7b , the oxygen atom to which R ^7b is bonded, and the carbon atom to which the oxygen atom and R ^7c 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.

Specific examples of the group (7-1) include, for example, when R ^7b in the formula (7-2a) or (7-2b) is an alkyl group, a 1-methoxyethyl group, a 1-ethoxyethyl group, a 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.
When R ^7b is an aliphatic cyclic group, a 1-cyclohexyloxyethyl group, a 1- (2-adamantyl) oxymethyl group, a group represented by the following formula (7-1-1) (1- (1-adamantyl) oxyethyl group) and the like.
In addition, when R ^7b is an aromatic cyclic hydrocarbon group, a group represented by the following formula (7-1-2) (1- (2-naphthyl) oxyethyl group) and the like can be given.
Among these, a 1-ethoxyethyl group is particularly preferable.

Group (7-3):
The group (7-3) is a group represented by the following general formula (7-3). In the group (7-3), when an acid is generated from the component (B1) by exposure, a bond between an oxygen atom bonded to R ^7e and a carbon atom bonded to R ^7c and R ^7d is generated by the acid. ^{off, -C (R 7c) (R} 7d) -OR 7b is dissociated.

［式（７−３）中、Ｒ^７ｂ〜Ｒ^７ｄはそれぞれ前記と同じであり、Ｒ^７ｅは２価の脂肪族環式基である。］

[In Formula (7-3), R ^{7b to} R ^7d are the same as defined above, and R ^7e is a divalent aliphatic cyclic group. ]

In the general formula (7-3), R ^{7b to} R ^7d are the same as R ^{7b to} R ^7d in the general formula (7-2b), respectively.
Examples of the divalent aliphatic cyclic group for R ^7e include groups obtained by further removing one hydrogen atom from the aliphatic cyclic group for R ^7b .

In the structural unit (a12 ^H), the acid dissociable, dissolution inhibiting group-containing group to replace the hydrogen atoms of hydroxyl groups of hydroxystyrene, among the above, groups (7-1) are preferred, the general formula (7-1b ) Is more preferred, and tert-butyloxycarbonyl group (t-boc group) is most preferred.

In the component (A1-2), as the structural unit (a12), one type may be used alone, or two or more types may be used in combination. For example, as the structural unit (a12), only the structural unit (a12 ^A ) may be used, or only the structural unit (a12 ^H ) may be used, or they may be used in combination. As the structural unit (a2 ^A ) or the structural unit (a2 ^H ), one type may be used alone, or two or more types may be used in combination.
In the component (A1-2), it is preferable to use only one of the structural unit (a12 ^A ) and the structural unit (a12 ^H ).
In the component (A1-2), the proportion of the structural unit (a12) may be appropriately set in consideration of the balance with the structural unit (a11), lithography properties, and the like.
For example, when the component (A1-2) has the structural unit (a12 ^A ) and does not have the structural unit (a12 ^H ), the proportion of the structural unit (a12 ^A ) in the component (A1-2) is (A1 -2) 5-40 mol% is preferable with respect to the sum total of all the structural units which comprise a component, and 10-30 mol% is more preferable. 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 component (A1-2) has the structural unit (a12 ^H ) and does not have the structural unit (a12 ^A ), the proportion of the structural unit (a12 ^H ) in the component (A1-2) is (A1- 2) 5-60 mol% is preferable with respect to the total of all the structural units which comprise a component, and 10-50 mol% is more preferable. 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.

Structural unit (a13):
The structural unit (a13) is a structural unit derived from styrene.
“Structural unit derived from styrene” means a structural unit formed by cleavage of an ethylenic double bond of styrene. “Styrene” refers to styrene in which a hydrogen atom is bonded to a carbon atom at the α-position (carbon atom to which the phenyl group is bonded), and a substituent (an atom or group other than a hydrogen atom) on the carbon atom in the α-position. Including those that are joined. Examples of the substituent bonded to the α-position carbon atom include the same groups as those described as the substituent bonded to the α-position carbon atom in the description of hydroxystyrene in the structural unit (a11).
Hereinafter, styrene in which a hydrogen atom is bonded to the α-position carbon atom is referred to as unsubstituted styrene, and that in which the substituent is bonded to the α-position carbon atom is referred to as α-substituted styrene. If there is no particular limitation, the “styrene” may be either unsubstituted styrene or α-substituted styrene.
Styrene may have a substituent bonded to its benzene ring. Examples of the substituent include the same groups as those described above for the substituent that may be bonded to the benzene ring of hydroxystyrene in the description of the structural unit (a11).
As the structural unit (a13), for example, a structural unit represented by general formula (a13-1) shown below can be exemplified.

［式中、Ｒ^０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。］

[Wherein, R ⁰ is the same as defined 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; is there. ]

In formula (a13-1), examples of R ⁰ and R ⁷ ′ are the same as R ⁰ and R ⁶ ′ in formula (a11-1).
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 (a13), one type of structural unit may be used alone, or two or more types of structural units may be used in combination.
When the component (A1-2) has the structural unit (a13), the proportion of the structural unit (a13) in the component (A1-2) is based on the total of all the structural units constituting the component (A1-2). 1-40 mol% is preferable and 5-30 mol% is more preferable. The effect by having a structural unit (a13) is high as it is more than the lower limit of this range, and the balance with another structural unit is favorable as it is below an upper limit.

  The component (A1-2) may optionally have other structural units other than the structural units (a11) to (a13) as long as the effects of the present invention are not impaired. Examples of the other structural units include the structural units (a2) to (a4) and a structural unit (a5 ′) described later. In addition to these, many conventionally known resins can be used as resist resins for ArF excimer laser, KrF excimer laser (preferably for ArF excimer laser), and the like.

Suitable examples of the component (A1-2) include a copolymer having the structural unit (a11) and the structural unit (a12 ^A ), the structural unit (a11), the structural unit (a12 ^A ), and the structural unit (a13). ), A copolymer having the structural unit (a11) and the structural unit (a12 ^H ), a copolymer having the structural unit (a11), the structural unit (a12 ^H ) and the structural unit (a13), etc. Is mentioned.

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 the 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

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography (GPC)) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 30000, 2000 to 2000 20000 is most preferred. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
In addition, the dispersity (Mw / Mn) of the component (A1) is not particularly limited, and is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and 1.0 to 2.5. Most preferred. Mn represents a number average molecular weight.

[(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.

As the component (A), one type may be used alone, or two or more types may be used in combination.
The content of the component (A) in the positive resist composition may be adjusted according to the resist film thickness to be formed.

[Component (B)]
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よいアルキル基、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 —C (═O) — (O) _n —R ⁵¹ , wherein R ⁵⁰ is an alkylene group or a single bond, and R ⁵¹ is an acid dissociable group or an acid non-dissociating group. N is 0 or 1. ] 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, 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 —C (═O) — (O) _n —R ⁵¹ in which the hydrogen atom of the aryl group may be substituted, the alkylene group for R ⁵⁰ is a linear or branched alkylene Group is preferable, and the number of carbon atoms is preferably 1 to 5. 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). For example, the acid dissociable group is exemplified in the description of the component (A). Examples include the same acid dissociable, dissolution inhibiting groups. Among them, the tertiary alkyl ester type is preferable.
The acid non-dissociable group for R ⁵¹ is preferably a decyl group, a tricyclodecanyl group, an adamantyl group, a 1- (1-adamantyl) methyl group, a tetracyclododecanyl group, an isobornyl group, or a norbornyl group.

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 decyl 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.

In formula (b-1), any two of R ¹ ″ to R ³ ″ may be bonded to each other to form a ring together with the sulfur atom in the formula. The ring may be saturated or unsaturated. The ring may be monocyclic or polycyclic. For example, when one or both of the two forming a ring is a cyclic group (cyclic alkyl group or aryl group), a polycyclic ring (fused ring) is formed when they are combined.
When two of R ¹ ″ to R ³ ″ are combined to form a ring, one ring containing a sulfur atom in the ring skeleton in the formula is a 3 to 10 membered ring including the sulfur atom. Of these, a 5- to 7-membered ring is particularly preferable.
Specific examples of the ring formed by combining two of R ¹ ″ to R ³ ″ include benzothiophene, dibenzothiophene, 9H-thioxanthene, thioxanthone, thianthrene, phenoxathiin, tetrahydrothiophenium, tetrahydro Examples include thiopyranium.
When 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, the remaining one is preferably an aryl group.

Of the cation moiety 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 triphenylsulfonium. Preferable specific examples in the case of having a skeleton include, for example, cation moieties represented by the following formulas (I-1-1) to (I-1-14).

  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-11-10) to (I-11-13).

［式中、Ｒ^９は、置換基を有していてもよいフェニル基、置換基を有していてもよい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、置換基を有していてもよいナフチル基、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水酸基であり、ｕは１〜３の整数である。］

[Wherein, R ⁹ is a phenyl group which may have a substituent, a naphthyl group which may have a substituent or an alkyl group having 1 to 5 carbon atoms, and R ¹⁰ represents a substituent. A phenyl group which may have, a naphthyl group which may have a substituent, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms or a hydroxyl group, u is an integer of 1 to 3 It is. ]

［式中、Ｚ^４は単結合、メチレン基、硫黄原子、酸素原子、窒素原子、カルボニル基、−ＳＯ−、−ＳＯ_２−、−ＳＯ_３−、−ＣＯＯ−、−ＣＯＮＨ−または−Ｎ（Ｒ_Ｎ）−（該Ｒ_Ｎは炭素数１〜５のアルキル基である。）であり；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。］

[In the formula, Z ⁴ represents a single bond, a methylene group, a sulfur atom, an oxygen atom, a nitrogen atom, a carbonyl group, —SO—, —SO ₂ —, —SO ₃ —, —COO—, —CONH— or —N ( R _N ) — (wherein R _N is an alkyl group having 1 to 5 carbon atoms); R ^{41 to} R ⁴⁶ are each independently an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxyl group or hydroxyalkyl. N _{1 to} n ₅ are each independently an integer of 0 to 3, and n ₆ is an integer of 0 to 2. ]

In the formulas (I-11-10) to (I-11-11), in R ^{9 to} R ¹⁰ , the substituent that the phenyl group or naphthyl group may have may be represented by R ¹ ″ to R ³ ″. The thing similar to what was mentioned as a substituent which an aryl group may have is mentioned. As the substituent that the alkyl group have the ^{R 9 ~R 10, R 1 "} ~R 3" are the same as those of the substituent which may be alkyl groups have in the Can be mentioned.
u is an integer of 1 to 3, and 1 or 2 is most preferable.
In formulas (I-11-12) to (I-11-13), in R ^{41 to} R ⁴⁶ , the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, and in particular, a linear or branched alkyl group A group is more preferable, and a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-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.

In formulas (b-1) to (b-2), 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, for example, a halogen atom, a hetero atom, an alkyl group, a formula: XQ ^1- [where 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 heteroatom” (hereinafter sometimes referred to as a heteroatom-containing substituent) may be composed of only the heteroatom, or may be a group containing a group other than the heteroatom or an atom. May be.

Examples of the hetero atom-containing substituent that may substitute a part of carbon atoms constituting the aliphatic hydrocarbon 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- and the like. In the case of -NH-, the substituent (alkyl group, acyl group, etc.) that may substitute for H preferably has 1 to 10 carbon atoms, and more preferably 1 to 8 carbon atoms. Particularly preferably, it has 1 to 5 carbon atoms.
When the aliphatic hydrocarbon group is cyclic, these substituents may be included in the ring structure.

Examples of the hetero atom-containing substituent that may substitute part or all of the hydrogen atoms constituting the aliphatic hydrocarbon group include a halogen atom, an alkoxy group, a hydroxyl group, —C (═O) —R ⁸⁰ [ R ⁸⁰ is an alkyl group. ], -COOR ⁸¹ [R ⁸¹ is a hydrogen atom or an alkyl group. ], Halogenated alkyl groups, halogenated alkoxy groups, amino groups, amide groups, nitro groups, oxygen atoms (= O), sulfur atoms, sulfonyl groups (SO ₂ ) and the like.
Examples of the halogen atom as the heteroatom-containing substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
The alkyl group in the alkoxy group as the heteroatom-containing substituent may be linear, branched or cyclic, or a combination thereof. The carbon number is preferably 1-30. When the alkyl group is linear or branched, the carbon number is preferably 1-20, more preferably 1-17, still more preferably 1-15, 10 is particularly preferred. Specific examples thereof include those similar to the specific examples of the linear or branched saturated hydrocarbon group exemplified below. When the alkyl group is cyclic (when it is a cycloalkyl group), the carbon number is preferably 3 to 30, more preferably 3 to 20, still more preferably 3 to 15, and 4 to 12 carbon atoms. It is particularly preferred that the number of carbon atoms is 5-10. The alkyl group may be monocyclic or polycyclic. Specific examples include groups in which one or more hydrogen atoms have been removed from monocycloalkane, groups in which one or more hydrogen atoms have been removed from polycycloalkanes such as bicycloalkane, tricycloalkane, and tetracycloalkane. . Specific examples of the monocycloalkane include cyclopentane and cyclohexane. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. In these cycloalkyl groups, some or all of the hydrogen atoms bonded to the ring may or may not be substituted with a substituent such as a fluorine atom or a fluorinated alkyl group.
In —C (═O) —R ⁸⁰ and —COOR ⁸¹ as the hetero atom-containing substituent, the alkyl group in R ⁸⁰ and R ⁸¹ is the same as the alkyl group ^{exemplified as} the alkyl group in the alkoxy group. Can be mentioned.
Examples of the alkyl group in the halogenated alkyl group as the heteroatom-containing substituent include the same alkyl groups as mentioned for the alkyl group in the alkoxy group. As the halogenated alkyl group, a fluorinated alkyl group is particularly preferred.
Examples of the halogenated alkoxy group as the heteroatom-containing substituent include groups in which some or all of the hydrogen atoms of the alkoxy group have been substituted with the halogen atoms. The halogenated alkoxy group is preferably a fluorinated alkoxy group.
Examples of the hydroxyalkyl group as the heteroatom-containing substituent include groups in which at least one hydrogen atom of the alkyl group mentioned as the alkyl group in the alkoxy group is substituted with a hydroxyl group. 1-3 are preferable and, as for the number of the hydroxyl groups which a hydroxyalkyl group has, 1 is the most preferable.

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, decyl 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. As the unsaturated hydrocarbon group, a propenyl group is particularly preferable.

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 groups represented by the following formulas (L1) to (L5) and (S1) to (S4).

［式中、Ｑ”は、酸素原子もしくは硫黄原子を含んでいてもよいアルキレン基、酸素原子または硫黄原子であり、ｍは０または１の整数である。］

[Wherein Q ″ is an alkylene group, an oxygen atom or a sulfur atom which may contain an oxygen atom or a sulfur atom, and m is an integer of 0 or 1.]

In the formula, the alkylene group in Q ″ is preferably linear or branched, and preferably has 1 to 5 carbon atoms. Specifically, 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 )-, an alkylmethylene group such as —C (CH ₂ CH ₃ ) ₂ —; an 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 - alkyl groups such as, trimethylene group (n- propylene _{group) [- CH 2 CH 2 CH} 2 -] _{; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3 Tetramethylene group _{[-CH 2 CH 2 CH 2 CH} 2 -];; - CH 2 alkyltetramethylene groups such as _{- CH (CH 3) CH 2} CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 An alkyltetramethylene group such as CH ₂ —, a pentamethylene group [—CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ —], etc. Among these, a methylene group or an alkylmethylene group is preferable, and a methylene group, —CH (CH ₃ ) — or —C (CH ₃ ) ₂ — is particularly preferred.
The alkylene group may contain an oxygen atom (—O—) or a sulfur atom (—S—). Specific examples thereof include groups in which —O— or —S— is interposed between the terminal or carbon atoms of the alkylene group. For example, —O—R ⁹⁴ —, —S—R ⁹⁵ —, —R ⁹⁶ — O-R ^{<97 >} -, -R < ^{98 >} -S-R ^<99> -etc. are mentioned. Here, R ^{94 to} R ⁹⁹ are each independently an alkylene group. Examples of the alkylene group include the same alkylene groups as those described above for Q ″. Among them, —O—CH ₂ —, —CH ₂ —O—CH ₂ —, —S—CH ₂ — , —CH ₂ —S—CH ₂ — and the like are preferable.

In these aliphatic cyclic groups, some or all of the hydrogen atoms may be substituted with substituents. Examples of the substituent include an alkyl group, a halogen atom, an alkoxy group, a hydroxyl group, —C (═O) —R ⁸⁰ [R ⁸⁰ is an alkyl group. ], -COOR ⁸¹ [R ⁸¹ is a hydrogen atom or an alkyl group. ], Halogenated alkyl groups, halogenated alkoxy groups, amino groups, amide groups, nitro groups, oxygen atoms (= O), sulfur atoms, sulfonyl groups (SO ₂ ) and the like.
Examples of the alkyl group as the substituent include the same alkyl groups as those described above for the alkoxy group as the heteroatom-containing substituent.
As the alkyl group, an alkyl group having 1 to 6 carbon atoms is particularly preferable. The alkyl group is preferably linear or branched, 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, Examples include pentyl group, isopentyl group, neopentyl group, hexyl group and the like. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
As the halogen atom, alkoxy group, —C (═O) —R ⁸⁰ , —COOR ⁸¹ , halogenated alkyl group, and halogenated alkoxy group as the substituent, a hydrogen atom constituting the aliphatic hydrocarbon group, respectively. The same thing as the thing quoted as the hetero atom containing substituent which may substitute a part or all of is mentioned.
Among the above, the substituent for substituting the hydrogen atom of the aliphatic cyclic group is preferably an alkyl group, an oxygen atom (= O), or a hydroxyl group.
The number of substituents possessed by the aliphatic cyclic group may be one or two or more. When having a plurality of substituents, the plurality of substituents may be the same or different.

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. Examples of the polycyclic aliphatic cyclic group include groups obtained by removing one or more hydrogen atoms from the polycycloalkane, and groups represented by the above (L2) to (L5) and (S3) to (S4). Etc. are preferred.

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.
In addition, the anion part of these onium salts may be methanesulfonate, n-propanesulfonate, n-butanesulfonate, n-octanesulfonate, 1-adamantanesulfonate, 2-norbornanesulfonate, d-camphor-10-sulfonate, benzenesulfonate, Onium salts substituted with alkyl sulfonates such as fluorobenzene sulfonate and p-toluene sulfonate 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は置換基であり、Ｒ^８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, ^{R 8} is a hydrogen atom, the number of carbon atoms It is a 1-5 alkyl group or a C1-C5 halogenated alkyl group. ]

［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 include an alkyl group and a heteroatom-containing substituent. Examples of the alkyl group include those similar to the alkyl group mentioned as the substituent that the aromatic hydrocarbon group may have in the description of X. In addition, the heteroatom-containing substituent is the same as the heteroatom-containing substituent that may substitute part or all of the hydrogen atoms constituting the aliphatic hydrocarbon group in the description of X. Is 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.
Examples of the alkyl group and halogenated alkyl group for R ⁸ include the same alkyl groups and halogenated alkyl groups as those described above for R.
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.

In the general formula (b-1) or (b-2), the anion moiety (R ⁴ ″ SO ₃ ⁻ ) is R ⁷ ″ -COO ⁻ [wherein R ⁷ ″ is an alkyl group or a fluorinated alkyl group. An onium salt-based acid generator replaced with a cation group can be used (the cation moiety is the same as (b-1) or (b-2)).
Examples of R ⁷ ″ include the same as R ⁴ ″ described above.
Specific examples of the “R ⁷ ″ —COO ⁻ ” include trifluoroacetate ion, acetate ion, 1-adamantanecarboxylate ion 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 for R ³³ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and more preferably 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 heteroaryl groups in which some of the carbon atoms constituting the ring of these groups are substituted with heteroatoms such as oxygen, sulfur, and nitrogen atoms. 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 for 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 N-tenyl 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.
0.5-50 mass parts is preferable with respect to 100 mass parts of (A) component, and, as for content of (B) component in a positive resist composition, 1-40 mass parts is more preferable. 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 ingredients]
The positive resist composition may further contain a nitrogen-containing organic compound (hereinafter referred to as “component (D)”) as an optional component.
The component (D) is not particularly limited as long as it acts as an acid diffusion controller, 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.
As the component (D), a low molecular compound (non-polymer) is usually used. Examples of the component (D) include amines such as aliphatic amines and aromatic amines, and aliphatic amines are preferable, and secondary aliphatic amines and tertiary aliphatic amines are particularly preferable. Here, the aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 20 carbon atoms.
Examples of the aliphatic amine include an amine (alkylamine 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 20 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 , Trialkylamines such as tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, Li isopropanolamine, di -n- octanol amine, tri -n- octanol amine, stearyl diethanolamine, alkyl alcohol amines such as lauryl diethanolamine. Among these, trialkylamine and / or alkyl alcohol amine are 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.
Other aliphatic amines include tris (2-methoxymethoxyethyl) amine, tris {2- (2-methoxyethoxy) ethyl} amine, tris {2- (2-methoxyethoxymethoxy) ethyl} amine, tris {2 -(1-methoxyethoxy) ethyl} amine, tris {2- (1-ethoxyethoxy) ethyl} amine, tris {2- (1-ethoxypropoxy) ethyl} amine, tris [2- {2- (2-hydroxy Ethoxy) ethoxy} ethylamine and the like.
Examples of the aromatic amine include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, diphenylamine, triphenylamine, tribenzylamine, 2,6-diisopropylaniline, 2,2 Examples include '-dibilidyl, 4,4'-dibilidyl 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.

The positive resist composition further comprises, as an optional component, an organic carboxylic acid, and a phosphorus oxo acid and derivatives thereof for the purpose of preventing sensitivity deterioration, improving the resist pattern shape, stability with time, etc. You may contain the at least 1 sort (s) of compounds selected from the group (henceforth (E) component).
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.
(E) A component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

  If desired, the positive resist composition further includes miscible additives such as an additional resin for improving the performance of the resist film, a surfactant for improving the coating property, a dissolution inhibitor, and a plasticizer. Stabilizers, colorants, antihalation agents, dyes, and the like can be added as appropriate.

The positive 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 of known solvents for chemically amplified resists can be used. Two or more types 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.
(S) The usage-amount of a component is not specifically limited, It is a density | concentration which can be apply | coated to a board | substrate etc., and is suitably set according to a coating film thickness. Generally, it is used so that the solid content concentration of the resist composition is in the range of 1 to 20% by mass, preferably 2 to 15% by mass.

<Second positive resist composition>
The second positive resist composition, that is, the chemically amplified positive resist composition used as the second film forming material in the pattern forming method of the present invention has higher energy than the first positive resist composition. As long as the solubility in an alkaline developer increases with the amount, among the many chemically amplified resist compositions proposed so far, as mentioned in the description of the first positive resist composition, Can be appropriately selected and used.
Examples of the second positive resist composition include a base material component (A ′) having an acid dissociable, dissolution inhibiting group (hereinafter referred to as “component (A ′)”) and an acid generator component that generates an acid upon exposure. (B ′) (hereinafter referred to as “component (B ′)”), and the base component (A ′) is more deprotective than the acid dissociable, dissolution inhibiting group of the base component (A). Have a high acid dissociable, dissolution inhibiting group. When such a positive resist composition is used, in step (2), the amount of energy supplied by the exposure amount and the PEB temperature is such that the acid dissociable, dissolution inhibiting group of the substrate component (A) is dissociated, and the group By performing exposure and PEB so that the acid dissociable, dissolution inhibiting group of the material component (A ′) has an energy amount that does not dissociate, a reverse pattern can be formed as described above.
The combination of acid dissociable, dissolution inhibiting groups in the first positive resist composition and the second positive resist composition will be described in detail in detail. This selection method will be described later.

[(A ′) component]
As the component (A ′), the component (A) except that it has an acid dissociable, dissolution inhibiting group having a higher deprotection energy (hard to dissociate) than the acid dissociable, dissolution inhibiting group of the substrate component (A). The thing similar to what was mentioned by description of the component is mentioned.
In the present invention, the component (A ′) contains a resin component (A1 ′) (hereinafter sometimes referred to as the component (A1 ′)) whose solubility in an alkaline developer is increased by the action of an acid. Preferably, those containing a structural unit derived from an acrylate ester are more preferable.
As the component (A1 ′), in particular, a resin component (A1′-1) having a structural unit (a1 ′) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group (hereinafter referred to as (A1′-1) ) Component)).
In addition to the structural unit (a1 ′), the component (A1′-1) further includes a structural unit derived from an acrylate ester containing a lactone-containing cyclic group and an —SO ₂ -containing cyclic group. It is preferable to have at least one structural unit (a2 ′) selected from the group consisting of structural units derived from acrylate esters.
In addition to the structural unit (a1 ′) or the structural units (a1 ′) and (a2 ′), the component (A1′-1) is an acrylic ester containing a polar group-containing aliphatic hydrocarbon group It is preferable to have a structural unit (a3 ′) derived from
The component (A1′-1) is added to the structural unit (a1 ′), or to the structural units (a1 ′) and (a2 ′), or to the structural units (a1 ′) and (a3 ′). In addition to the structural units (a1 ′), (a2 ′), and (a3 ′), it is preferable to further include a structural unit (a5 ′) represented by the following general formula (a5 ′).
Each structural unit may be used alone or in combination of two or more.

［式（ａ５’）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；Ｙ^１は脂肪族環式基であり、Ｚは第３級アルキル基含有基またはアルコキシアルキル基であり；ａは１〜３の整数であり、ｂは０〜２の整数であり、且つａ＋ｂ＝１〜３であり；ｃ、ｄ、ｅはそれぞれ独立して０〜３の整数である。］

[In the formula (a5 ′), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; Y ¹ represents an aliphatic cyclic group, and Z represents a third group. A secondary alkyl group-containing group or an alkoxyalkyl group; a is an integer of 1 to 3, b is an integer of 0 to 2 and a + b = 1 to 3; c, d and e are each independently And an integer from 0 to 3. ]

Among the above, examples of the structural unit (a1 ′) include the same structural units as the structural unit (a1) mentioned in the description of the component (A1).
In the component (A1 ′), the proportion of the structural unit (a1 ′) is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, based on all structural units constituting the component (A1 ′). More preferred is ˜50 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.

Among the above, examples of the structural unit (a2 ′) include the same structural units as the structural unit (a2) mentioned in the description of the component (A1).
In the component (A1 ′), the proportion of the structural unit (a2 ′) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, based on the total of all structural units constituting the component (A1 ′). 20-50 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.

Among the above, examples of the structural unit (a3 ′) include the same structural units as the structural unit (a3) mentioned in the description of the component (A1).
In the component (A1 ′), the proportion of the structural unit (a3 ′) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, based on all structural units constituting the component (A1 ′). Preferably, 5 to 25 mol% is more preferable.

The structural unit (a5 ′) is a structural unit represented by the general formula (a5 ′).
In formula (a5 ′), R is the same as R in the description of the structural unit (a1). R is preferably a hydrogen atom or a methyl group.
Y ¹ is an aliphatic cyclic group. The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity.
The “aliphatic cyclic group” in the structural unit (a5 ′) 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 structure of the basic ring (aliphatic ring) excluding the substituent of the “aliphatic cyclic group” is not limited to being a ring composed of carbon and hydrogen (hydrocarbon ring), but the ring (aliphatic ring) The ring structure may contain an oxygen atom. The “hydrocarbon ring” may be either saturated or unsaturated, but is usually preferably saturated.
The aliphatic cyclic group may be either a polycyclic group or a monocyclic group. Examples of the aliphatic cyclic group include a monocycloalkane which may or may not be substituted with a lower alkyl group, a fluorine atom or a fluorinated alkyl group; a bicycloalkane, a tricycloalkane, or a tetracycloalkane. Groups obtained by removing two or more hydrogen atoms from polycycloalkanes and the like. More specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing two or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. .
Examples of the aliphatic cyclic group include two or more hydrogen atoms from tetrahydrofuran or tetrahydropyran which may or may not be substituted with a lower alkyl group, a fluorine atom or a fluorinated alkyl group. Examples include groups other than.
The aliphatic cyclic group in the structural unit (a5 ′) is preferably a polycyclic group, and among them, a group obtained by removing two or more hydrogen atoms from adamantane is preferable.

  In the general formula (a5 ′), Z represents a tertiary alkyl group-containing group or an alkoxyalkyl group.

(Tertiary alkyl group-containing group)
“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. .
The “other atom or group other than the tertiary alkyl group” constituting the tertiary alkyl group-containing group together with the tertiary alkyl group includes a carbonyloxy group, a carbonyl group, an alkylene group, an oxygen atom (—O— ) And the like.

Examples of the tertiary alkyl group-containing group in Z 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 groups represented by the following general formula (I).

In formula (I), 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.
Moreover, it is preferable that the total carbon number of group represented by general formula (I) is 4-7, it is more preferable that it is 4-6, and it is most preferable that it is 4-5.
Preferred examples of the group represented by the general formula (I) 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 further preferably an alkylene group having 2 to 2 carbon atoms.
Examples of the chain-like tertiary alkyloxycarbonyl group include a group represented by the following general formula (II).
^R 21 ^{to R 23} in the formula (II) is the same as ^R 21 ^{to R 23} in general formula (I).
The chain-like tertiary alkyloxycarbonyl group is preferably a tert-butyloxycarbonyl group (t-boc) or a tert-pentyloxycarbonyl group.

Examples of the chain-like tertiary alkyloxycarbonylalkyl group include a group represented by the following general formula (III).
^R 21 ^{to R 23} in the formula (III) are the same as ^R 21 ^{to R 23} in general formula (I).
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 and a tert-butyloxycarbonylethyl group are 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. A tert-butyloxycarbonyl group (t-boc) is most preferred.

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, 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 [1] or [2] group as the 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. .
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.

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 lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (═O), and the like.
Examples of the group [2] include groups represented by the following chemical 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 lower 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 (I). Can be mentioned.

(Alkoxyalkyl group)
As an alkoxyalkyl group in Z, group represented by the following general formula (V) is mentioned, for example.

In the formula, R ⁴¹ is a linear, branched or cyclic alkyl group.
When R ⁴¹ 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 ⁴¹ 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. For example, one or more hydrogen atoms from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group And the like except for. More 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.
^R42 is 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.
As the alkoxyalkyl group for Z, a group represented by the following general formula (VI) is particularly preferable.

In the formula (VI), R ⁴¹ is the same as described above, and R ⁴³ and R ⁴⁴ are each independently a linear or branched alkyl group or a hydrogen atom.
In R ⁴³ and R ⁴⁴ , 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 ⁴³ and R ⁴⁴ is a hydrogen atom and the other is a methyl group.

  Among these, as Z, a tertiary alkyl group-containing group is preferable, a group represented by the general formula (II) is more preferable, and a tert-butyloxycarbonyl group (t-boc) is most preferable.

In the general formula (a5 ′), a is an integer of 1 to 3, b is an integer of 0 to 2, and a + b = 1 to 3.
a is preferably 1 or 2, and more preferably 1.
b is preferably 0.
a + b is preferably 1 or 2, and more preferably 1.
c is an integer of 0 to 3, preferably 0 or 1, and more preferably 0.
d is an integer of 0 to 3, preferably 0 or 1, and more preferably 0.
e is an integer of 0 to 3, preferably 0 or 1, and more preferably 0.
When b is 1 or more, the structural unit (a5 ′) is also included in the definition of the structural unit (a3 ′), but the structural unit represented by the formula (a5 ′) is the structural unit (a5 ′). Applicable but not applicable to the structural unit (a3 ′).

  As the structural unit (a5 ′), a structural unit represented by general formula (a5′-1-1), (a5′-1-2) or (a5′-2) shown below is particularly preferable. The structural unit represented by '-1-1) is more preferable.

［式中、Ｒ，Ｚ，ｂ，ｃ，ｄ，ｅはそれぞれ前記と同じである。］

[Wherein R, Z, b, c, d and e are the same as defined above. ]

［式中、Ｒ，Ｚ，ｂ，ｃ，ｄ，ｅはそれぞれ前記と同じである。式中の複数のｅおよびＺはそれぞれ互いに異なっていてもよい。］

[Wherein R, Z, b, c, d and e are the same as defined above. A plurality of e and Z in the formula may be different from each other. ]

［式中、Ｒ，Ｚ，ａ，ｂ，ｃ，ｄ，ｅはそれぞれ前記と同じであり、ｃ”は１〜３の整数である。］

[Wherein, R, Z, a, b, c, d and e are the same as defined above, and c ″ is an integer of 1 to 3]

In the formula (a5′-2), c ′ is an integer of 1 to 3, preferably 1 or 2, and more preferably 1.
When c in the formula (a5′-2) is 0, the oxygen atom at the terminal of the carbonyloxy group (—C (═O) —O—) of the acrylate ester is bonded to the oxygen atom in the cyclic group. It is preferably not bonded to a carbon atom. That is, when c is 0, there are two or more carbon atoms between the terminal oxygen atom and the oxygen atom in the cyclic group (the number of carbon atoms is 1 (that is, acetal bond and It is preferable that the above is excluded).

  The monomer for deriving the structural unit (a5 ′) is, for example, a compound represented by the following general formula (a5′-0) (an acrylate ester containing an aliphatic cyclic group having 1 to 3 alcoholic hydroxyl groups): The hydroxyl group can be synthesized by protecting a part or all of the hydroxyl group with a tertiary alkyl group-containing group or an alkoxyalkyl group using a known method.

［式中、Ｒ，Ｙ^１，ａ，ｂ，ｃ，ｄ，ｅはそれぞれ前記と同じである。］

[Wherein, R, Y ¹ , a, b, c, d, and e are the same as defined above. ]

  The proportion of the structural unit (a5 ′) in the component (A1′-1) is preferably 1 to 45 mol% with respect to the total of all structural units constituting the component (A1′-1). More preferably, it is 45 mol%, More preferably, it is 5-40 mol%, Most preferably, it is 5-35 mol%. By setting it to the lower limit value or more, the solubility in an organic solvent such as an alcohol organic solvent, a fluorine organic solvent, or an ether organic solvent having no hydroxyl group is improved. And the balance is good.

The component (A1′-1) may contain other structural units other than the structural units (a1 ′) to (a3 ′) and (a5 ′) as long as the effects of the present invention are not impaired.
The other structural unit is not particularly limited as long as it is another structural unit not classified into the above structural units (a1 ′) to (a3 ′) and (a5 ′). Many things conventionally known can be used as what is used for resist resin for lasers (preferably for ArF excimer lasers).
Examples of the other structural units include the structural units (a4) and (a11) to (a13) mentioned in the description of the component (A1).

The component (A1′-1) is preferably a copolymer having the structural units (a1 ′), (a2 ′), (a3 ′) and (a5 ′). Examples of such a copolymer include a copolymer comprising the structural units (a1 ′), (a2 ′), (a3 ′) and (a5 ′), the structural units (a1 ′), (a2 ′), Examples thereof include copolymers composed of (a3 ′), (a4) and (a5 ′).
In the component (A1′-1), the total proportion of the structural units derived from the acrylate ester (the structural units (a1) to (a4), (a5 ′), etc.) is the same as the component (A1′-1). 50 mol% or more is preferable with respect to the total of all the structural units to comprise, 80 mol% or more is more preferable, and 100 mol% may be sufficient.
In the component (A ′), as the component (A1′-1), one type may be used alone, or two or more types may be used in combination.

In addition to the component (A1′-1), the component (A1 ′) is preferably derived from a structural unit (a11 ′) derived from hydroxystyrene and an acrylate ester having an acid dissociable, dissolution inhibiting group. A structural unit derived from hydroxystyrene, wherein at least one of the hydrogen atoms of the hydroxyl group in the structural unit is substituted with an acid dissociable, dissolution inhibiting group or an organic group containing an acid dissociable, dissolution inhibiting group And a resin component (A1′-2) (hereinafter referred to as (A1′-2) component) having at least one structural unit (a12 ′) selected from the group consisting of:
The component (A1′-2) preferably further has a structural unit (a13 ′) derived from styrene.

Among the above, examples of the structural unit (a11 ′) include the same structural units as the structural unit (a11) mentioned in the description of the component (A1).
In the component (A1′-2), the proportion of the structural unit (a11) is preferably 50 to 90 mol% with respect to the total of all the structural units constituting the component (A1-2), and is preferably 55 to 85 mol. % Is more preferable. When it is at least the lower limit of the range, moderate alkali solubility is obtained, and the effect of containing the structural unit (a11) is sufficiently obtained. When the amount is not more than the upper limit of the range, the balance with other structural units is good.

Among the above, a structural unit derived from an acrylate ester having an acid dissociable, dissolution inhibiting group in the structural unit (a12 ′) (hereinafter referred to as the structural unit (a12 ′ ^A )), a structural unit derived from hydroxystyrene Wherein at least one hydrogen atom of the hydroxyl group in the structural unit is substituted with an acid-dissociable, dissolution-inhibiting group or an organic group containing an acid-dissociable, dissolution-inhibiting group (hereinafter referred to as a structural unit (a12 ′ ^H )). .) Are the same as the structural unit (a12 ^A ) and the structural unit (a12 ^H ) mentioned in the description of the component (A1).
In the component (A1′-2), the proportion of the structural unit (a12 ′) may be set as appropriate in consideration of the balance with the structural unit (a11 ′), lithography properties, and the like.
For example, when the component (A1′-2) has the structural unit (a12 ′ ^A ) and does not have the structural unit (a12 ′ ^H ), the structural unit (a12 ′ ^A ) in the component (A1′-2) 5-40 mol% is preferable with respect to the sum total of all the structural units which comprise a (A1'-2) component, and 10-30 mol% is more preferable. 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 component (A1′-2) has the structural unit (a12 ′ ^H ) and does not have the structural unit (a12 ′ ^A ), the proportion of the structural unit (a12 ′ ^H ) in the component (A1′-2) Is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, based on the total of all structural units constituting the component (A1′-2). 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.

Among the above, examples of the structural unit (a13 ′) include the same structural units as the structural unit (a3) mentioned in the description of the component (A1).
When the component (A1′-2) has the structural unit (a13 ′), the proportion of the structural unit (a13 ′) in the component (A1′-2) is the entire structural unit constituting the component (A1′-2). 5-40 mol% is preferable with respect to the sum total, and 10-30 mol% is more preferable. The effect by having a structural unit (a13) is high as it is more than the lower limit of this range, and the balance with another structural unit is favorable as it is below an upper limit.

  The component (A1′-2) may optionally have other structural units other than the structural units (a11 ′) to (a13 ′) as long as the effects of the present invention are not impaired. Examples of the other structural units include the structural units (a2 ′) to (a5 ′). In addition to these, many conventionally known resins can be used as resist resins for ArF excimer laser, KrF excimer laser (preferably for ArF excimer laser), and the like.

Preferable examples of the component (A1′-2) include a copolymer having the structural unit (a11 ′) and the structural unit (a12 ′ ^A ), the structural unit (a11 ′), and the structural unit (a12 ′ ^A ). And a copolymer having a structural unit (a13 ′), a copolymer having a structural unit (a11 ′) and a structural unit (a12 ′ ^H ), a structural unit (a11 ′), a structural unit (a12 ′ ^H ), and a structural unit And a copolymer having (a13 ′).

The component (A1 ′) can be obtained by polymerizing a monomer that derives each structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN). .
In addition, for the component (A1 ′), a chain transfer agent such as HS—CH ₂ —CH ₂ —CH ₂ —C (CF ₃ ) ₂ —OH is used in combination in the above polymerization, -C terminated _{(CF 3)} may be introduced 2 -OH group. As described above, a copolymer introduced with a hydroxyalkyl group in which a part of hydrogen atoms of the 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

The mass average molecular weight (Mw) of the component (A1 ′) (polystyrene conversion standard by gel permeation chromatography (GPC)) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 30000, 2000 ˜20,000 is most preferred. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
Further, the dispersity (Mw / Mn) of the component (A1 ′) is not particularly limited, and is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and 1.0 to 2.5. Is most preferred. Mn represents a number average molecular weight.

[(B ′) component]
Examples of the component (B ′) include the same components as the component (B) mentioned in the description of the first positive resist composition.
As the component (B ′), one type may be used alone, or two or more types may be used in combination.
The content of the component (B ′) in the second positive resist composition 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 ingredients]
The second positive resist composition may further contain a nitrogen-containing organic compound (hereinafter referred to as (D ′) component) as an optional component.
Examples of the component (D ′) include the same components as the component (D) mentioned in the description of the first positive resist composition.
As the component (D ′), one type may be used alone, or two or more types may be used in combination.
(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.

The second positive resist composition further includes, as an optional component, an organic carboxylic acid, a phosphorus oxo acid, and its oxo acid for the purpose of preventing sensitivity deterioration, improving the resist pattern shape, stability with time, and the like. It may contain at least one compound selected from the group consisting of derivatives (hereinafter referred to as component (E ′)).
Examples of the component (E ′) include the same components as the component (E) mentioned in the description of the first positive resist composition.
As the component (E ′), one type may be used alone, or two or more types may be used in combination.
(E ') component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A') component.

  If desired, the second positive resist composition may further contain miscible additives such as an additional resin for improving the performance of the resist film, a surfactant for improving coatability, and a dissolution inhibitor. , Plasticizers, stabilizers, colorants, antihalation agents, dyes, and the like can be added as appropriate.

The second positive resist composition can be produced by dissolving the material in an organic solvent.
In the present invention, the second positive resist composition, as the organic solvent, is the same as described for the second film forming material (S ′) component (an organic solvent that does not dissolve the first resist film). Containing.
Examples of the component (S ′) are the same as those described in the description of the step (2).
The (S ′) component used in the second positive resist composition may be a single type or two or more types.
In the same manner as described for the second film-forming material, the second positive resist composition has an (S ″) component ((S ′) within a range that does not impair the effect of using the (S ′) component. ) Organic solvents other than the component) may be contained.
As the (S ″) component, the (S) component mentioned in the description of the first positive resist composition is particularly preferable.
The compounding amount of the component (S ″) is preferably 0 to 20% by mass and more preferably 1 to 15% by mass in the total organic solvent compounded in the second positive resist composition.
The amount of the total organic solvent used in the second positive resist composition is not particularly limited, and is usually an amount such that the second positive resist composition becomes a liquid having a concentration that can be applied onto the support. Is used. Generally, it is used so that the solid content concentration is in the range of 1 to 20% by mass, preferably 2 to 15% by mass.

  As described above, the chemical amplification type positive resist composition has been described in detail as the second film forming material, but the present invention is not limited thereto, and the second film forming material is a non-chemical amplification type. A resist composition may be used. 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.

<Selection Method of First Positive Resist Composition and Second Positive Resist Composition>
As described above, in the present invention, the second positive resist composition does not increase the solubility in an alkali developer with the same amount of energy as that of the first positive resist composition or less. In step (2), the exposure amount and post-exposure bake temperature are set so that only the first resist pattern in the exposed region is removed by alkali development.
Therefore, the first positive resist composition and the second positive resist composition used in the pattern forming method of the present invention so that the lithography conditions (exposure amount, PEB temperature, etc.) in the steps (1) and (2) satisfy the above conditions. A combination of positive resist compositions is selected.
That is, the selection of each of the first positive resist composition and the second positive resist composition is such that the second positive resist composition has the same or less energy than the first positive resist composition. The amount is adjusted so that the solubility in an alkali developer does not increase.

As a method for selecting a combination of the first positive resist composition and the second positive resist composition, for example, the effective PEB temperature of the second film formed using the second positive resist composition is set. minimum value (T _min2) is, to be higher than the lowest value of the effective PEB temperature of the first resist film (T _min1), also, preferably how to set their difference becomes a desired value Can be mentioned. In this case, for example, even if the exposure amount in the step (2) is an amount capable of increasing the solubility of the second film in the alkaline developer, the PEB temperature T _PEB2 in the step (2) is _set to T _min2 or more T _By setting the temperature within the range less than _min1, only the first resist pattern has increased solubility in an alkaline developer.
T _min1 and T _min2 can be adjusted by adjusting the compositions of the first positive resist composition and the second positive resist composition used, respectively.
For example, when using both the first positive resist composition and the second positive resist composition containing an acid generator component that generates an acid upon exposure and a base material component having an acid dissociable, dissolution inhibiting group, The adjustment can be performed by, for example, the following methods (2a) to (2c). All of these methods (2a) to (2c) are considered to affect the ease of the deprotection reaction of the acid dissociable, dissolution inhibiting group.
(2a) An acid dissociable, dissolution inhibiting group having a higher deprotection energy than the acid dissociable, dissolution inhibiting group of the substrate component of the first positive resist composition as the substrate component of the second positive resist composition The method using what has this.
(2b) A method using a substrate component of the second positive resist composition that is less susceptible to exposure and / or PEB damage than the substrate component of the first positive resist composition.
(2c) A method in which the blending amount of the acid generator component in the second positive resist composition is less than the blending amount of the acid generator component in the first positive resist composition.
Any one of these methods may be used, or two or more thereof may be used in combination. In the present invention, it is preferable to use at least method (2a).

For example, in the case of the method (2a), the first positive resist composition and the second positive resist composition each have a base material component having an acid dissociable, dissolution inhibiting group (the above-described (A) component, (A ′ ) Component), the acid dissociable, dissolution inhibiting group in the second positive resist composition has a higher deprotection energy than the acid dissociable, dissolution inhibiting group in the first positive resist composition. To do. As a result, the second positive resist composition is less likely to increase the solubility in an alkaline developer during exposure and PEB than the first positive resist composition, and T _min2 is It becomes higher than T _min1 .
The difference in deprotection energy of each acid dissociable, dissolution inhibiting group is preferably about 2 kcal / mol or more, and more preferably 2.5 kcal / mol or more.

The deprotection energy of the acid dissociable, dissolution inhibiting group can be obtained from the analysis result obtained by the analysis method including the following steps 1 to 4.
Step 1: A resist composition is prepared using a polymer into which a specific protecting group has been introduced.
Step 2: A resist film is formed from the resist composition prepared in Step 1, and the entire surface is exposed. The exposure amount at this time is the same as the optimum exposure amount (Eop).
Step 3: Analyzing the deprotection reaction using the deprotection reaction analyzer (PAGA-100) manufactured by RISOTEC JAPAN Co., Ltd. for the resist film after the exposure process (According to this apparatus, while performing the PEB process) By collecting the IR spectrum of the resist film, the structural change of the resist composition during the PEB treatment can be confirmed.
Step 4: Collect data for a plurality of PEB temperatures and perform analysis.

The structural unit having an acid dissociable, dissolution inhibiting group (the structural unit (a1), the structural unit (a1 ′), the structural unit (a12), the structural unit (a12 ′), etc.) will be described in detail. In the structural unit, the deprotection energy of the acid dissociable dissolution inhibiting group is determined by the structure of the acid dissociable dissolution inhibiting group or the structure of the acid dissociable dissolution inhibiting group in the side chain portion of the structural unit. It depends on whether they are connected.
The following are specific structures of structural units derived from an acid dissociable, dissolution inhibiting group or an acrylate ester having an acid dissociable, dissolution inhibiting group, and the first positive resist composition and the second positive resist Which of the resist compositions is suitable will be described. However, the present invention is not limited to this.

(A) A tertiary alkyl ester-type acid dissociable, dissolution inhibiting group directly bonded to the carboxy group of acrylic acid to form a tertiary alkyl ester, and a ring skeleton of a monovalent aliphatic cyclic group Furthermore, a methyl group is bonded to a carbon atom bonded to an atom adjacent to the acid dissociable, dissolution inhibiting group (—O— in —C (═O) —O—) to form a tertiary carbon atom. Group.
Here, “acrylic acid” is not only acrylic acid (CH ₂ ═CHCOOH) in which a hydrogen atom is bonded to the α-position carbon atom (carbon atom to which the carbonyl group of acrylic acid is bonded), but also the α-position carbon atom. The concept also includes those in which a substituent (atom or group other than a hydrogen atom) is bonded to. Examples of the substituent bonded to the α-position carbon atom include an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, and a hydroxyalkyl group. The α-position carbon atom of the acrylate ester is a carbon atom to which the carbonyl group of acrylic acid is bonded unless otherwise specified.
The fact that the group is directly bonded to the carboxy group of acrylic acid means that the group is replacing the hydrogen atom of the carbonyl group of acrylic acid.
As the “tertiary alkyl ester type acid dissociable, dissolution inhibiting group that is directly bonded to the carboxy group of acrylic acid to form a tertiary alkyl ester”, specifically, in the description of the structural unit (a1), X ′ in the formula (a1-1) mentioned can be mentioned.
“A group in which a tertiary carbon atom is formed by bonding a methyl group to a carbon atom bonded to an atom adjacent to the acid dissociable, dissolution inhibiting group on the ring skeleton of a monovalent aliphatic cyclic group”. Examples thereof include those in which R ¹⁴ in formulas (1-1) to (1-9) mentioned in the description of the structural unit (a1) is a methyl group.
Such an acid dissociable, dissolution inhibiting group has a relatively high deprotection energy and is difficult to dissociate. Therefore, it is suitable for the second positive resist composition. However, an acid dissociable dissolution inhibiting group having a higher deprotection energy than the acid dissociable dissolution inhibiting group (for example, a tertiary alkyl ester which is directly bonded to the carboxyl group of (e) acrylic acid described later). When a tertiary alkyl ester type acid dissociable, dissolution inhibiting group that is an aliphatic branched group) is used in the second positive resist composition, it may be used in the first positive resist composition. it can. For example, the acid dissociable, dissolution inhibiting group can be used as the resist composition [1] described above when the first resist pattern is formed by a double patterning process.

(A) A tertiary alkyl ester-type acid dissociable, dissolution inhibiting group that is directly bonded to the carboxy group of acrylic acid to form a tertiary alkyl ester, and a ring skeleton of a monovalent aliphatic cyclic group In addition, an alkyl group having 2 or more carbon atoms is bonded to a carbon atom bonded to an atom adjacent to the acid dissociable, dissolution inhibiting group (—O— in —C (═O) —O—), and a tertiary carbon atom The group on which is formed.
“On the ring skeleton of the monovalent aliphatic cyclic group, a tertiary carbon atom is formed by bonding an alkyl group having 2 or more carbon atoms to a carbon atom bonded to an atom adjacent to the acid dissociable, dissolution inhibiting group. Examples of the “group” include those in which R ¹⁴ in the formulas (1-1) to (1-9) is an alkyl group having 2 or more carbon atoms.
Such an acid dissociable, dissolution inhibiting group has a relatively low deprotection energy (e.g., compared to the group shown in (a) above) and is easily dissociated. For example, the 2-methyl-2-adamantyl group (M) in which R ¹⁴ in the formula (1-1) is a methyl group is compared with the 2-ethyl-2-adamantyl group (E) in which R ¹⁴ is an ethyl group. Then, the deprotection energy of M is 11.2 [kcal / mol], whereas the deprotection energy of E is 8.3 [kcal / mol]. The deprotection energy of the ethylcyclohexyl group in which g in the formula (1-2) is 2 and R ¹⁴ is an ethyl group is 8.1 [kcal / mol].
Therefore, the acid dissociable, dissolution inhibiting group is suitable for the first positive resist composition. However, when an acid dissociable dissolution inhibiting group (for example, an acetal type acid dissociable dissolution inhibiting group) having lower deprotection energy than the acid dissociable dissolution inhibiting group is used in the first positive resist composition, It can also be used for the positive resist composition.
The acid dissociable, dissolution inhibiting group is suitable for the resist composition [2] when the first resist pattern is formed by the double patterning process. However, when an acid dissociable dissolution inhibiting group (for example, an acetal type acid dissociable dissolution inhibiting group described later) having a lower deprotection energy than the acid dissociable dissolution inhibiting group is used for the resist composition [2], the resist composition It can also be used for the object [1].

(C) A tertiary alkyl ester-type acid dissociable, dissolution inhibiting group that is directly bonded to the carboxy group of acrylic acid to form a tertiary alkyl ester, which is a monovalent aliphatic cyclic group, and And a group having a branched alkylene having a tertiary carbon atom bonded to the group.
Examples of the “group having a monovalent aliphatic cyclic group and a group having a branched alkylene having a tertiary carbon atom bonded to the monovalent aliphatic cyclic group” are given in the description of the structural unit (a1), for example. Examples include groups represented by formulas (2-1) to (2-6).
Such an acid dissociable, dissolution inhibiting group has a relatively high deprotection energy and is difficult to dissociate. Therefore, it is suitable for the second positive resist composition.

(D) A tertiary alkyl ester type acid dissociable, dissolution inhibiting group that is directly bonded to the carboxy group of acrylic acid to form a tertiary alkyl ester, and is a group that is aliphatic branched.
As the “aliphatic branched group”, for example, the aliphatic branched acid dissociable, dissolution inhibiting group mentioned as the tertiary alkyl ester type acid dissociable, dissolution inhibiting group in the description of the structural unit (a1). (For example, a group represented by the formula —C (R ⁷¹ ) (R ⁷² ) (R ⁷³ )).
Such an aliphatic branched acid dissociable, dissolution inhibiting group has a relatively high deprotection energy and is difficult to dissociate. Therefore, it is suitable for the second positive resist composition.

(E) A tertiary alkyl ester type acid dissociable, dissolution inhibiting group which is not directly bonded to the carboxy group of acrylic acid but bonded via a linking group.
Specifically, X ′ in the formula (a1-3) exemplified in the description of the structural unit (a1) can be given.
Such an acid dissociable, dissolution inhibiting group has a relatively low deprotection energy due to the presence of a linking group, compared to the case where a group having the same structure is directly bonded without a linking group. It's easy to do. Therefore, it is suitable for the first positive resist composition.

(F) Acetal type acid dissociable, dissolution inhibiting group.
Specific examples of the acetal type acid dissociable, dissolution inhibiting group include the same groups as those described in the description of the structural unit (a1).
The acetal type acid dissociable, dissolution inhibiting group has a relatively low deprotection energy and is easily dissociated. For example, the deprotection energy of the adamantoxymethyl group is 8.4 [kcal / mol]. Therefore, it is suitable for the first positive resist composition.

(G) A polyfunctional acid dissociable, dissolution inhibiting group.
Examples of the polyfunctional acid dissociable, dissolution inhibiting group include those described in JP 2005-325325 A (general formula: R— [O—CH ₂ ] _n — (wherein R has 20 or less carbon atoms). represents an organic group having a valence of n or more, and n represents an integer of 2 to 5.)).
The polyfunctional acid dissociable, dissolution inhibiting group has a relatively low deprotection energy and is easily dissociated. Therefore, it is suitable for the first positive resist composition.

An acid dissociable, dissolution inhibiting group (hereinafter referred to as protective group 1) of the first positive resist composition and an acid dissociable, dissolution inhibiting group (hereinafter referred to as protective group 2) of the second positive resist composition. In particular, the following combinations are preferable.
[Combination 1]: The protecting group 1 is at least one selected from the group consisting of (a) and (e), and the protecting group 2 is (a).
[Combination 2]: The protecting group 1 is at least one selected from the group consisting of (a) and (e), and the protecting group 2 is (e).
[Combination 3]: The protecting group 1 is at least one selected from the group consisting of (a), (b) and (e), and the protecting group 2 is (d).

In addition, when forming the 1st resist pattern in a process (1) by a double patterning process, 2 or more types (for example, said resist composition [1] and [2]) are used as a 1st positive resist composition. It will be. In this case, an acid dissociable, dissolution inhibiting group (hereinafter referred to as protective group 1a) of the resist composition [1] and an acid dissociable, dissolution inhibiting group (hereinafter referred to as protective group 1b) of the resist composition [2]. In particular, the following combinations are preferable.
[Combination A]: The protecting group 1a is the above (a), and the protecting group 1b is at least one selected from the group consisting of the above (a) and (e).
When the combination A is employed, the combination 3 is preferably the combination of the protecting group 1 and the protecting group 2.

As a specific example of the method (2b), for example, an acrylic resin is used as the base component of the first positive resist composition, and a hydroxystyrene resin is used as the base component of the second positive resist composition. Is mentioned. That is, the acrylic resin such as the above-described (A1-1) component and (A1′-1) component, and the hydroxystyrene resin such as the (A1-2) component and (A1′-2) component, The absorption of ArF excimer laser (wavelength 193 nm) is different, and it is considered that the hydroxystyrene-based resin is less likely to proceed with the deprotection reaction of the acid dissociable, dissolution inhibiting group when exposed to ArF excimer laser. For example, a resin having a structural unit derived from an acrylate ester in which —C (═O) —O—C (CH ₃ ) ₃ is bonded to a carbon atom at the α-position, and a hydroxyl group in the structural unit derived from hydroxystyrene And the resin having a structural unit in which the hydrogen atom is substituted with —C (═O) —O—C (CH ₃ ) ₃ , the latter resin has a deprotection reaction of —C (CH ₃ ) _3. Difficult to progress. Therefore, even if the acid dissociable, dissolution inhibiting groups are the same, a reverse pattern can be formed by changing the type of resin.

In addition, the acid generator component of the first positive resist composition is a relatively strong acid, and the acid generator component of the second positive resist composition is compared with the generated acid. T _min2 can be made higher than T _min1 by using a weak acid.
Hereinafter, which acid generator is suitable for the first positive resist composition and the second positive resist composition will be described with specific examples. However, the influence of the acid generator on the effective PEB temperature is smaller than that of the acid dissociable, dissolution inhibiting group, and is not particularly limited thereto.

(1) An onium salt acid generator having an anion moiety represented by R ⁴ ″ —SO ₃ ^— , wherein a fluorine atom is bonded to a carbon atom adjacent to the sulfur atom of SO ₃ ^— For example, R ⁴ ″ is a perfluoroalkyl group).
Such an acid generator is suitable for the first positive resist composition because the generated acid is a relatively strong acid. However, it can also be used for the second positive resist composition. In particular, the onium salt acid generator having an anion moiety represented by the formulas (b1) to (b7) is also suitable for the second positive resist composition.
(2) the ^R 4 "-SO ₃ ^- a onium salt-based acid generator having an anion moiety represented by, ^{R 4"} comprises a fluorine atom, and SO ₃ ^- carbon atom adjacent to the sulfur atom of the In which no fluorine atom is bonded.
Such an acid generator can be used in any positive resist composition.
(3) An onium salt acid generator having an anion moiety represented by R ⁴ ″ —SO ₃ ^— , wherein R ⁴ ″ is an alkyl group.
Such an acid generator is suitable for the second positive resist composition because the generated acid is a relatively weak acid.
(4) An onium salt acid generator having an anion moiety represented by the formula (b-3) or (b-4).
The acid generator is suitable for the first positive resist.
(5) A diazomethane acid generator.
The acid generator can be used for any positive resist, but is suitable for the second positive resist composition.
(6) An oxime sulfonate acid generator.
The acid generator can be used for any positive resist, but is suitable for the second positive resist composition.

EXAMPLES Hereinafter, the present invention will be described with reference to examples, but the scope of the present invention is not limited to these examples.
<Test Example 1>
Each component shown in Table 1 was mixed and dissolved to prepare a resist composition (chemically amplified positive resist composition).

Each abbreviation in Table 1 has the following meaning. Moreover, the numerical value in [] is a compounding quantity (mass part).
(A) -01: A copolymer having a mass average molecular weight (Mw) of 7000 and a dispersity of 1.7 represented by the following chemical formula (A) -1. In the formula, the symbol on the lower right of () indicates the ratio (mol%) of the structural unit to which the symbol is attached, and is a1: a2: a3 = 45: 35: 20.
(A) -02: A copolymer having a mass average molecular weight (Mw) of 7000 and a dispersity of 1.7 represented by the following chemical formula (A) -2. In the formula, the symbol at the lower right of () indicates the ratio (mol%) of the structural unit to which the symbol is attached, and is a1: a2: a3 = 35: 45: 20.
(A) -03: a copolymer having a mass average molecular weight (Mw) of 7000 and a dispersity of 1.7 represented by the following chemical formula (A) -3. In the formula, the symbol on the lower right of () indicates the ratio (mol%) of the structural unit to which the symbol is attached, and is a1: a2: a3 = 40: 40: 20.
(B) -01: (4-Methylphenyl) diphenylsulfonium nonafluoro-n-butanesulfonate.
(D) -01: Tri-n-pentylamine.
(E) -01: Salicylic acid.
(S) -01: γ-butyrolactone.
(S) -02: Mixed solvent of PGMEA and PGME (PGMEA: PGME = 6: 4 (mass ratio).

The following evaluation was performed using the resist composition obtained above.
An 8-inch silicon wafer was subjected to a HMDS treatment at a treatment temperature of 90 ° C. and a treatment time of 36 seconds to carry out a hydrophobic treatment.
A resist composition (0-1) is applied onto the silicon wafer using a spinner, prebaked (PAB) at 110 ° C. for 60 seconds on a hot plate, and then dried to obtain a film thickness of 100 nm. The resist film (first resist film) was formed.
Next, the exposure amount is set to 0 to 100 mJ with respect to the first resist film by using an ArF exposure apparatus NSR-S302 (product name, manufactured by Nikon Corporation, NA (numerical aperture) = 0.60, σ 0.60). Open frame exposure (exposure not through a photomask) was performed while changing within the range of / cm ² .
Thereafter, PEB treatment was performed for 60 seconds at a predetermined PEB temperature (85 ° C., 90 ° C., 95 ° C., 100 ° C. or 110 ° C.). The dissolution rate (nm / s) of the resist film on the treated wafer with respect to an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution at 23 ° C. using a resist development analyzer RDA-800 manufactured by Risotech Japan Co., Ltd. )
Then, taking the exposure amount on the horizontal axis and the dissolution rate on the vertical axis, a dissolution rate curve for the developer of the first resist film when the PEB treatment was performed at each PEB temperature was prepared. The result is shown in FIG.
From the results shown in FIG. 3, the resist composition (0-1) shows saturation at a value lower than 1 nm / s without increasing the dissolution rate even when the exposure dose is increased at a PEB temperature of 90 ° C. or less. Was confirmed. On the other hand, when the PEB temperature was 100 ° C. or higher, the dissolution rate was significantly increased when the exposure amount exceeded a predetermined value.
From the above results, in the case of a resist film formed using the resist composition (0-1), if the PEB temperature is 100 ° C. or higher, the resist film is dissolved / developed by a 2.38 mass% TMAH aqueous solution (23 ° C.). It has been found that it exhibits a resolvable degree of solubility.
Similarly, also in the case of the resist compositions (0-2) and (0-3), the PEB temperature at which the solubility that can be dissolved and removed was developed was confirmed. As a result, it was found that the PEB temperature was 100 ° C. or higher for the resist composition (0-3) and 80 ° C. or higher for (0-3).
From the above results, the PEB temperature necessary for developing the resist composition so that it can be dissolved and removed by development with an alkaline developer mainly depends on the type of the acid dissociable, dissolution inhibiting group, It was confirmed that there was a gap in the PEB temperature depending on the type of dissociable dissolution inhibiting group.

<Preparation of resist composition>
Each component shown in Table 2 was mixed and dissolved to prepare a resist composition (chemically amplified positive resist composition).

Each abbreviation in Table 2 has the following meaning. Moreover, the numerical value in [] is a compounding quantity (mass part).
(A) -1: a copolymer having a mass average molecular weight (Mw) of 10000 and a dispersity (Mw / Mn) of 1.65 represented by the following structural formula (A) -11. In the formula, the symbol on the lower right of () indicates the proportion (mol%) of the structural unit to which the symbol is attached.
(A) -1 ′: a copolymer having a mass average molecular weight (Mw) of 7000 and a dispersity (Mw / Mn) of 1.7 represented by the following structural formula (A) -12. In the formula, the symbol on the lower right of () indicates the ratio (mol%) of the structural unit to which the symbol is attached, and is a1: a2: a3 = 45: 35: 20.
(A) -2: a copolymer having a mass average molecular weight (Mw) of 7000 and a dispersity (Mw / Mn) of 1.65 represented by the following structural formula (A) -21. In the formula, the symbol on the lower right of () indicates the proportion (mol%) of the structural unit to which the symbol is attached.
(A) -2 ′: a copolymer having a mass average molecular weight (Mw) of 7000 and a dispersity (Mw / Mn) of 1.5 represented by the following structural formula (A) -22. In the formula, the symbol on the lower right of () indicates the proportion (mol%) of the structural unit to which the symbol is attached.
(B) -1: a compound represented by the following structural formula (B) -1.
(D) -1: tri-n-pentylamine.
(E) -1: salicylic acid.
(S) -1: Mixed solvent of PGMEA and PGME (PGMEA: PGME = 6: 4 (mass ratio).
(S) -2: A mixed solvent of 1-butoxy-2-propanol (PGB) and PGMEA (PGB: PGMEA = 9: 1 (mass ratio)).

<Example 1>
An organic antireflection film composition “ARC29” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto an 8-inch silicon wafer using a spinner, and baked on a hot plate at 205 ° C. for 60 seconds to dry. Thus, an organic antireflection film having a film thickness of 82 nm was formed.
On the organic antireflection film, the resist composition (1-1) is applied using a spinner, prebaked (PAB) at 90 ° C. for 60 seconds on a hot plate, and dried. A resist film (first resist film) having a thickness of 100 nm was formed. Next, an ArF excimer laser (193 nm) is applied to the first resist film using an ArF exposure apparatus NSR-S302 (manufactured by Nikon; NA (numerical aperture) = 0.60, 2/3 annular illumination). A mask pattern 1 with a line-and-space resist pattern (hereinafter, the line-and-space resist pattern is referred to as an LS pattern) having a line width of 120 nm and a pitch of 240 nm with the exposure amount shown in Table 3 (1st exposure amount). Irradiated through.
Thereafter, post-exposure baking (PEB) was performed for 60 seconds at the temperature shown in Table 3 (1st PEB temperature), and development was further performed at 23 ° C. with an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution for 30 seconds. Then, water rinsing was performed using pure water for 30 seconds, followed by shake-off drying. As a result, a target LS pattern was formed on the first resist film.
Subsequently, each LS pattern was post-baked for 60 seconds at the temperature shown in Table 3.
Thereafter, the resist composition (2-1) is applied onto each LS pattern using a spinner, prebaked (PAB) at 90 ° C. for 60 seconds on a hot plate, and dried to form a film. A resist film (second resist film) having a thickness of 70 nm was formed. Next, an ArF excimer laser (193 nm) was applied to the second resist film using an ArF exposure apparatus NSR-S302 (Nikon Corporation; NA (numerical aperture) = 0.60, 2/3 annular illumination). Irradiation was performed by open frame exposure (exposure not via a photomask) at an exposure amount (2nd exposure amount) shown in Table 3. Thereafter, PEB is performed for 60 seconds at the temperature shown in Table 3 (2nd PEB temperature), and further developed with a 2.38 mass% TMAH aqueous solution at 23 ° C. for 30 seconds, and then rinsed with pure water for 30 seconds, Shake off and dry.
As a result, the line portion of the LS pattern formed in the first resist film is dissolved and removed by development after the open frame exposure, and the second resist is formed in the space portion of the LS pattern formed in the first resist film. A line derived from the film is formed, and an inverted pattern of the LS pattern formed on the first resist film (a space-and-line resist pattern having a space width of about 120 nm and a pitch of about 240 nm (hereinafter referred to as a space-and-line resist pattern SL). Pattern))) was formed.

In the formation of the reverse pattern, the reverse pattern was formed in the same manner except that the mask pattern 1 used for the exposure of the first resist film was changed to the following.
Mask pattern 2: A mask pattern targeting an LS pattern having a line width of 130 nm and a pitch of 260 nm.
Mask pattern 3: A mask pattern targeting an LS pattern having a line width of 140 nm and a pitch of 280 nm.
Mask pattern 4: A mask pattern targeting an LS pattern having a line width of 150 nm and a pitch of 300 nm.
As a result, in each example, an inverted pattern (SL pattern) of the LS pattern formed on the first resist film was formed.

[Example 2]
Example 1 except that the resist composition (2-1) was changed to the resist composition (2-2) and the exposure amount (2nd exposure amount) for the second resist film was changed to the exposure amount shown in Table 3. The same operation was performed.
As a result, as in Example 1, in the example using any of the mask patterns 1 to 4, an inverted pattern of the LS pattern formed on the first resist film was formed.

[Comparative Example 1]
The same operation as in Example 1 was performed except that the resist composition (2-1) was changed to the resist composition (2-3).
As a result, when developing the second resist film, not only the line pattern formed in the first resist film but also the second resist film is dissolved and removed, and the resist pattern is formed on the support. Not formed.

[Example 3]
In Example 1, except that the mask patterns 1 to 4 were changed to the following mask patterns 1 ′ to 4 ′ and the exposure amount (2nd exposure amount) for the second resist film was changed to the exposure amount shown in Table 3, The same operation as in Example 1 was performed.
Mask pattern 1 ′: A mask pattern that targets an SL pattern having a space width of 120 nm and a pitch of 240 nm.
Mask pattern 2 ′: A mask pattern that targets an SL pattern having a space width of 130 nm and a pitch of 260 nm.
Mask pattern 3 ′: A mask pattern that targets an SL pattern having a space width of 140 nm and a pitch of 280 nm.
Mask pattern 4 ′: A mask pattern that targets an SL pattern having a space width of 150 nm and a pitch of 300 nm.
As a result, after developing the second resist film, the line portion of the SL pattern formed on the first resist film is dissolved and removed by development after the open frame exposure, and formed on the first resist film. A line derived from the second resist film was formed in the space portion of the SL pattern, and an inverted pattern (LS pattern) of the SL pattern formed on the first resist film was formed.

[Example 4]
In Example 2, except that the mask patterns 1 to 4 were changed to the following mask patterns 1 ′ to 4 ′, respectively, and the exposure amount (2nd exposure amount) for the second resist film was changed to the exposure amount shown in Table 3, The same operation as in Example 1 was performed.
Mask pattern 1 ′: A mask pattern that targets an SL pattern having a space width of 120 nm and a pitch of 240 nm.
Mask pattern 2 ′: A mask pattern that targets an SL pattern having a space width of 130 nm and a pitch of 260 nm.
Mask pattern 3 ′: A mask pattern that targets an SL pattern having a space width of 140 nm and a pitch of 280 nm.
Mask pattern 4 ′: A mask pattern that targets an SL pattern having a space width of 150 nm and a pitch of 300 nm.
As a result, after developing the second resist film, the line portion of the SL pattern formed on the first resist film is dissolved and removed by development after the open frame exposure, and formed on the first resist film. A line derived from the second resist film was formed in the space portion of the SL pattern, and an inverted pattern (LS pattern) of the SL pattern formed on the first resist film was formed.

<Preparation of resist composition-2>
Each component shown in Table 4 was mixed and dissolved to prepare a resist composition (chemically amplified positive resist composition).

In Table 4, (A) -1 ′, (D) -1, (E) -1, (S) -1, and (S) -2 are the same as those shown in Table 1 above, Each abbreviation has the following meaning. Moreover, the numerical value in [] is a compounding quantity (mass part).
(A) -3: Co-weight of mass average molecular weight (Mw) 7000 and dispersity (Mw / Mn) 1.56 represented by the following structural formula (A) -3 obtained by Polymer Synthesis Example 1 described later Coalescence. In the formula, the symbol on the lower right of () indicates the proportion (mol%) of the structural unit to which the symbol is attached. In the structural formula, the monomer (compound (1)) corresponding to the second structural unit from the left was synthesized in Monomer Synthesis Example 1 described later.
(A) -4: a copolymer having a mass average molecular weight (Mw) of 12000 and a dispersity (Mw / Mn) of 2.1 represented by the following structural formula (A) -4. In the formula, the symbol on the lower right of () indicates the proportion (mol%) of the structural unit to which the symbol is attached.
(A) -5: A copolymer having a mass average molecular weight (Mw) of 12000 and a dispersity (Mw / Mn) of 2.1 represented by the following structural formula (A) -5. In the formula, the symbol on the lower right of () indicates the proportion (mol%) of the structural unit to which the symbol is attached.
(A) -6: a copolymer having a mass average molecular weight (Mw) of 7000 and a dispersity (Mw / Mn) of 1.6 represented by the following structural formula (A) -6. In the formula, the symbol on the lower right of () indicates the proportion (mol%) of the structural unit to which the symbol is attached.
(B) -2: (4-methylphenyl) diphenylsulfonium nonafluoro-n-butanesulfonate.
(B) -3: Compound represented by the following formula (B) -3 (compound (II) obtained in Component (B) Synthesis Example 1 described later. Refer to Japanese Unexamined Patent Publication No. 2009-91350 for the anion moiety) .
(B) -4: Triphenylsulfonium d-camphor-10-sulfonate.
(B) -5: A compound represented by the following formula (B) -5 (synthesized according to the description in JP-A-2009-186852).
(S) -3: γ-butyrolactone.
(S) -4: Mixed solvent of PGEMA / PGME / CH = 45/35/25 (mass ratio).
(S) -5: Isobutanol.

<Example 5>
An organic antireflection film composition “ARC29” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto an 8-inch silicon wafer using a spinner, and baked on a hot plate at 205 ° C. for 60 seconds to dry. Thus, an organic antireflection film having a film thickness of 82 nm was formed.
The resist composition (1-3) is applied onto the organic antireflection film by using a spinner, subjected to PAB at 110 ° C. for 60 seconds on a hot plate, and dried to obtain a film thickness of 100 nm. The resist film (first resist film) was formed. Next, an ArF excimer laser (193 nm) is applied to the first resist film using an ArF exposure apparatus NSR-S302 (manufactured by Nikon; NA (numerical aperture) = 0.60, 2/3 annular illumination). Irradiation was performed through the mask pattern 1 with an exposure amount (1st exposure amount) shown in Table 5 and using an LS pattern with a line width of 130 nm and a pitch of 260 nm as a target.
Thereafter, PEB was carried out at 95 ° C. for 60 seconds, further developed with a 2.38 mass% TMAH aqueous solution at 23 ° C. for 30 seconds, then rinsed with pure water for 30 seconds, and then shaken off and dried. . As a result, a target LS pattern was formed on the first resist film.
Subsequently, the LS pattern was post-baked at 140 ° C. for 60 seconds.
Thereafter, the resist composition (2-4) is applied onto the LS pattern using a spinner, and subjected to PAB for 60 seconds at 90 ° C. on a hot plate, followed by drying, thereby forming a resist having a thickness of 120 nm. A film (second resist film) was formed. Next, an ArF excimer laser (193 nm) was applied to the second resist film using an ArF exposure apparatus NSR-S302 (Nikon Corporation; NA (numerical aperture) = 0.60, 2/3 annular illumination). Irradiation was performed by open frame exposure at an exposure amount (2nd exposure amount) shown in Table 5. Thereafter, PEB was performed at 90 ° C. for 60 seconds, followed by development with a 2.38 mass% TMAH aqueous solution at 23 ° C. for 30 seconds, and then water rinsing with pure water for 30 seconds, followed by drying by shaking.
As a result, the line portion of the LS pattern formed in the first resist film is dissolved and removed by development after the open frame exposure, and the second resist is formed in the space portion of the LS pattern formed in the first resist film. A line derived from the film was formed, and an inverted pattern of the LS pattern formed on the first resist film (SL pattern having a space width of about 130 nm and a pitch of about 260 nm was formed.

<Example 6>
Example 5 except that the resist composition (2-4) was changed to the resist composition (2-5) and the exposure amount (2nd exposure amount) for the second resist film was changed to the exposure amount shown in Table 5. The same operation was performed.
As a result, as in Example 5, an inverted pattern of the LS pattern formed on the first resist film was formed.

<Example 7: Reversal pattern formation after positive / positive double patterning>
<Example 5> except that the resist composition (1-4) was used in place of the resist composition (1-3) and the exposure was performed with the exposure amount (first exposure amount) shown in Table 6. Thus, an LS pattern having a line width of 130 nm and a pitch of 520 nm was formed.
Subsequently, the LS pattern was post-baked at 150 ° C. for 60 seconds.
Thereafter, the resist composition (2-6) is applied onto the LS pattern using a spinner, and subjected to PAB at 90 ° C. for 60 seconds on a hot plate, followed by drying. A resist film (resist film [2]) was formed. Next, an ArF excimer laser (193 nm) is applied to the resist film [2] using an ArF exposure apparatus NSR-S302 (manufactured by Nikon; NA (numerical aperture) = 0.60, 2/3 annular illumination). Irradiation was performed through a mask pattern with an exposure amount (2nd exposure amount) shown in Table 6. Thereafter, PEB was performed at 90 ° C. for 60 seconds, followed by development with a 2.38 mass% TMAH aqueous solution at 23 ° C. for 30 seconds, and then water rinsing with pure water for 30 seconds, followed by drying by shaking.
As a result, a second pattern having a line width of about 130 nm was formed at the center of the space of the LS pattern, and as a result, a 1: 1 LS pattern having a line width of 130 nm and a space width of 130 nm was formed. .
Subsequently, post-baking was performed on the LS pattern at 120 ° C. for 60 seconds.
Thereafter, the resist composition (3-1) is applied onto the LS pattern using a spinner, and subjected to PAB at 90 ° C. for 60 seconds on a hot plate, followed by drying, thereby forming a resist having a thickness of 120 nm. A film (resist film [3]) was formed. Next, an ArF excimer laser (193 nm) is applied to the resist film [3] using an ArF exposure apparatus NSR-S302 (Nikon Corporation; NA (numerical aperture) = 0.60, 2/3 annular illumination). Irradiation was performed by open frame exposure at an exposure amount (3rd exposure amount) shown in Table 6. Thereafter, PEB was carried out at 100 ° C. for 60 seconds, followed by development with a 2.38 mass% TMAH aqueous solution at 23 ° C. for 30 seconds, and then water rinsing with pure water for 30 seconds, followed by drying by shaking.
As a result, the line portion of the LS pattern (1: 1 LS pattern having a line width of 130 nm and a space width of 130 nm) formed using the resist composition (1-4) and the resist composition (2-6) is exposed by open frame exposure. A reversal pattern (space width of about 130 nm, pitch of about 260 nm SL pattern) in which a line derived from the resist film [3] was formed in the space portion of the LS pattern was dissolved and removed by later development. .

From the results of Example 7, two types of first positive resist compositions (for example, the resist compositions (1-4) and (2-6) described above) used for forming a first resist pattern by a double patterning process are used. ) And a second positive resist composition (for example, the resist composition (3-1)) used for the subsequent formation of the reverse pattern, the following relationships (1) to (2) are provided: It was confirmed that an inverted pattern of the first resist pattern formed by the double patterning process can be formed.
(1) The acid dissociation possessed by the deprotection energy of the acid dissociable, dissolution inhibiting group contained in the component (A) of the second positive resist composition is the acid dissociation possessed by the component (A) of the two first positive resist compositions. Higher than the deprotection energy of the soluble dissolution inhibiting group.
(2) As the (S) component of the second positive resist composition, one that does not dissolve the first resist pattern formed using each of the two first positive resist compositions is used.

[Monomer Synthesis Example 1]
In a 500 ml three-necked flask, under a nitrogen atmosphere, 20 g (105.14 mmol) of the following alcohol (1), 30.23 g (157.71 mmol) of ethyldiisopropylaminocarbodiimide (EDCI) hydrochloride and dimethylaminopyridine (DMAP) 0. After adding 300 g of a THF solution of 6 g (5 mmol), 16.67 g (115.66 mmol) of the following precursor (1) was added under ice cooling (0 ° C.), and the mixture was stirred at room temperature for 12 hours.
After confirming disappearance of the raw material by thin layer chromatography (TLC), 50 ml of water was added to stop the reaction. The reaction solvent was concentrated under reduced pressure, and the organic layer obtained by extraction three times with ethyl acetate was washed with water, saturated sodium bicarbonate and 1N-HCl aqueous solution in this order. The product obtained by distilling off the solvent under reduced pressure was dried to obtain the target compound (1).
The instrumental analysis results of the obtained compound were as follows.
¹ H-NMR (CDCl ₃ , 400 MHz): δ (ppm) = 6.22 (s, 1H, H ^a ), 5.70 (s, 1H, H ^b ), 4.71-4.85 (m, 2H, H ^{c, d} ), 4.67 (s, 2H, H ^k ), 3.40-3.60 (m, 2H, H ^{e, f} ), 2.58-2.70 (m, 1H, ^{H g), 2.11-2.21 (m,} 2H, H h), 2.00 (s, 3H, H i), 1.76-2.09 (m, 2H, H j).

[Polymer synthesis example 1]
In a three-necked flask connected with a thermometer and a reflux tube, 7.93 g (46.64 mmol) of compound (2), 8.00 g (25.32 mmol) of compound (1), 11.17 g (42.64 mmol) Compound (3), 3.13 g (18.66 mmol) of Compound (4), 3.46 g (14.66 mmol) of Compound (5) were dissolved in 50.54 g of methyl ethyl ketone (MEK). To this solution, 13.3 mmol of dimethyl azobisisobutyrate (V-601) as a polymerization initiator was added and dissolved. The resultant was dropwise added to 28.07 g of MEK heated to 78 ° C. in a nitrogen atmosphere over 3 hours. After completion of dropping, the reaction solution was heated and stirred for 4 hours, and then the reaction solution was cooled to room temperature. The obtained reaction polymerization solution was dropped into a large amount of a mixed solvent of n-heptane / isopropyl alcohol, and an operation for precipitating the polymer was performed. The precipitated white powder was separated by filtration and washed with a mixed solvent of n-heptane / isopropyl alcohol. After drying, 20 g of the target polymer compound (A) -3 was obtained.

[(B) Component Synthesis Example 1 (Synthesis of Compound (II))]
5.87 g of compound (I), 41.85 g of dichloromethane and 20.93 g of pure water were added to a beaker, and 4.16 g of the compound (VIII) was added thereto, followed by stirring at room temperature for 1 hour. Thereafter, the reaction solution was separated, and the organic phase was further washed with dilute hydrochloric acid and water. The obtained organic phase was added dropwise to 249.0 g of n-hexane to obtain 6.70 g of the target compound (II) as a white powder.
The counter anion of compound (I) is a mixture of bromide (Br) isomer and chloride (Cl) isomer, and the composition ratio was analyzed by ion chromatography. As a result, Br / Cl = 84/16 (wt%) )Met.

This compound (II) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 1.7-1.97 (m, 30 H, Ad + CH ₃ ), 2.21 (s, 2H, Ad), 2.31 (s, _{6H, Ar-CH 3),} 4.54 (s, 2H, OCH 2), 4.59 (s, 2H, CF 2 CH 2), 7.61 (s, 2H, Ar), 7.72-7 .83 (m, 10H, Ar).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 111.3.
From the results of the above analysis, it was confirmed that the compound (II) had a structure represented by the chemical formula (II).

  DESCRIPTION OF SYMBOLS 1 ... Support body, 2 ... 1st resist film, 3 ... Photomask, 6 ... 2nd film | membrane

Claims (12)

On the support, the first chemically amplified positive resist composition is applied to form a first resist film, the first resist film is exposed, post-exposure baking is performed, and alkali development is performed. Forming a resist pattern (1);
On the support on which the first resist pattern is formed, a second film-forming material containing an organic solvent that does not dissolve the first resist film is applied to form a second film, Exposing the region of the second film including the position where the first resist pattern is formed, performing post-exposure baking, and alkali developing (2),
A chemically amplified or non-chemically amplified positive resist composition in which the second film-forming material has a higher energy amount than the first chemically amplified positive resist composition and has increased solubility in an alkaline developer. Or a resin composition whose solubility in an alkali developer does not change depending on the amount of energy or energy ,
In the step (2), an exposure amount and a post-exposure bake temperature are set so that only the first resist pattern in the exposed region is removed by alkali development.   2. The chemically amplified positive resist composition in which the second film-forming material is a chemically amplified positive resist composition having a higher energy amount than that of the first chemically amplified positive resist composition and having increased solubility in an alkali developer. The pattern forming method according to 1. The first chemically amplified positive resist composition contains an acid generator component (B) that generates an acid upon exposure and a base material component (A) having an acid dissociable, dissolution inhibiting group,
The second film-forming material contains an acid generator component (B ′) that generates an acid upon exposure and a base component (A ′) having an acid dissociable, dissolution inhibiting group, and the base component ( The pattern formation method according to claim 2, wherein A ′) has an acid dissociable, dissolution inhibiting group having a higher deprotection energy than the acid dissociable, dissolution inhibiting group of the substrate component (A).   The said base material component (A ') contains the resin component (A1'-1) which has a structural unit (a1'-1) induced | guided | derived from the acrylate ester which has an acid dissociable, dissolution inhibiting group. The pattern formation method as described. The resin component (A1′-1) is further composed of a structural unit derived from an acrylate ester containing a lactone-containing cyclic group and a structural unit derived from an acrylate ester containing an —SO ₂ -containing cyclic group. The pattern formation method of Claim 4 which has at least 1 type of structural unit (a2 ') selected from the group which consists of.   The pattern forming method according to claim 4 or 5, wherein the resin component (A1'-1) further includes a structural unit (a3 ') derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group. The said resin component (A1'-1) is a pattern formation method as described in any one of Claims 4-6 which has further the structural unit (a5 ') represented by the following general formula (a5').

[In the formula (a5 ′), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; Y ¹ represents an aliphatic cyclic group, and Z represents a third group. A secondary alkyl group-containing group or an alkoxyalkyl group; a is an integer of 1 to 3, b is an integer of 0 to 2 and a + b = 1 to 3; c, d and e are each independently And an integer from 0 to 3. ]   The base component (A ′) includes a structural unit derived from hydroxystyrene (a11 ′), a structural unit derived from an acrylate ester having an acid dissociable, dissolution inhibiting group, and a structure derived from hydroxystyrene. At least one structural unit (a12 ′) selected from the group consisting of structural units in which at least one hydrogen atom of a hydroxyl group in the structural unit is substituted with an acid dissociable, dissolution inhibiting group-containing group; The pattern formation method of Claim 2 or 3 containing the resin component (A1'-2) which has this.   The pattern forming method according to claim 8, wherein the resin component (A1′-2) further includes a structural unit (a13 ′) derived from styrene.   The organic solvent that does not dissolve the first resist film is at least one selected from the group consisting of an alcohol solvent, a fluorine solvent, and an ether organic solvent having no hydroxyl group. The pattern forming method according to one item.   The pattern forming method according to claim 1, wherein the first resist pattern includes a line pattern and / or a dot pattern.   The pattern formation method according to claim 1, wherein the first resist pattern is formed by a double patterning process.

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