JP2010164958A - Resist composition for negative development, pattering method using the same, resist film, and pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist composition for negative development excellent in line width roughness (LWR), exposure latitude (EL) and depth of focus (DOF) and a pattering process using the same, in order to more stably form a high-accuracy fine pattern for manufacturing a highly-integrated and high-accuracy electronic device. <P>SOLUTION: The resist composition for negative development comprises (A) a resin which has an acid decomposable repeating unit and increases in polarity under the action of an acid to exhibit decreased solubility in a negative developer, (B) a photoacid generator which generates an acid having a specific structure upon irradiation with actinic rays or radiation, and (C) a solvent. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a negative developing resist composition and a pattern using the same, which are used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal and a thermal head, and other photofabrication lithography processes. The present invention relates to a forming method. In particular, the present invention relates to a negative developing resist composition suitable for exposure with an ArF exposure apparatus and an immersion projection exposure apparatus using far ultraviolet light having a wavelength of 300 nm or less as a light source, and a pattern forming method using the same. is there.

  Since the resist for KrF excimer laser (248 nm), an image forming method called chemical amplification has been used as an image forming method for a resist in order to compensate for sensitivity reduction due to light absorption. An example of a positive-type chemical amplification image forming method will be described. When exposed, the acid generator in the exposed area decomposes to generate an acid, and the acid generated in the exposure bake (PEB) is a reaction catalyst. Is used to change an alkali-insoluble group to an alkali-soluble group, and an exposed portion is removed by alkali development.

With the miniaturization of semiconductor elements, the wavelength of an exposure light source has been shortened and the projection lens has a high numerical aperture (high NA). Currently, an exposure machine using an ArF excimer laser having a 193 nm wavelength as a light source has been developed. These can be expressed by the following equations as is generally well known.
(Resolving power) = k ₁ · (λ / NA)
(Depth of focus) = ± k ₂ · λ / NA ²
Here, λ is the wavelength of the exposure light source, NA is the numerical aperture of the projection lens, and k ₁ and k ₂ are coefficients related to the process.

As a technique for increasing the resolving power, a so-called immersion method in which a high refractive index liquid (hereinafter also referred to as “immersion liquid”) is filled between the projection lens and the sample has been proposed.
This “immersion effect” means that when λ ₀ is the wavelength of the exposure light in the air, n is the refractive index of the immersion liquid with respect to the air, θ is the convergence angle of the light beam, and NA ₀ = sin θ. The above-described resolving power and depth of focus can be expressed by the following equations.
(Resolving power) = k ₁ · (λ ₀ / n) / NA ₀
(Depth of focus) = ± k ₂ · (λ ₀ / n) / NA ₀ ²
That is, the immersion effect is equivalent to using an exposure wavelength having a wavelength of 1 / n. In other words, in the case of a projection optical system with the same NA, the depth of focus can be increased n times by immersion. This is effective for all pattern shapes, and can be combined with a super-resolution technique such as a phase shift method and a modified illumination method which are currently being studied.

Further, as a technique for further improving the resolution, a double exposure technique (Double Exposure Technology) and a double patterning technique (Double Patterning Technology) have been proposed. This, in the preceding formulas of the resolving power is to reduce k _1, is positioned as a technique for enhancing the resolving power.

Conventionally, pattern formation of electronic devices such as semiconductor elements is performed by reducing and transferring a mask or reticle pattern, which is 4-5 times the size of the pattern to be formed, to an object to be exposed such as a wafer using a reduction projection exposure apparatus. It was.
However, with the miniaturization of dimensions, the conventional exposure method has a problem in that the light irradiated to adjacent patterns interferes with each other and the optical contrast is reduced. The design is divided into two or more, each mask is exposed independently, and an image is synthesized. In these double exposure methods, it is necessary to divide the design of the exposure mask, re-synthesize the image on the object to be exposed (wafer), and the pattern on the reticle faithfully adheres to the object to be exposed. It is necessary to devise the division of the mask design so that it can be reproduced.
An example in which the effect of these double exposure methods is studied for transferring a fine image pattern of a semiconductor element is introduced in Patent Document 1 and the like.

  However, if the conventional resist composition is simply applied to the conventional resist process for pattern formation, these double exposure methods require pattern formation near the resolution limit of the resist. The problem is that a large exposure margin and depth of focus cannot be obtained.

At present, various developers for g-line, i-line, KrF, ArF, EB, EUV lithography have been proposed, but 2.38 mass% TMAH (tetramethylammonium hydroxide) aqueous alkaline development. The liquid is used for general purposes.
However, it is of course desirable to form a pattern with a comprehensively good performance, but it is extremely difficult to find an appropriate combination of resist composition, developer, rinse solution, and the like necessary for that purpose. This was the actual situation, and improvements were required. In particular, as the resolution line width of the resist becomes finer, improvements in line edge roughness performance of line patterns and in-plane uniformity of pattern dimensions have been demanded.

Moreover, in the combination of a conventional resist composition and a developer, a specific resist composition is combined with a developer containing a high-polarity alkaline developer or a low-polar organic solvent to provide a system for forming a pattern. Only. That is, as shown in FIG. 1, in a positive system (combination of a resist composition and a positive developer), a region having a high light irradiation intensity in a spatial frequency of an optical image is selectively dissolved and removed. Only materials for patterning are provided. On the other hand, the negative system (resist composition and negative developer) only provides a material system that selectively dissolves and removes areas with low light irradiation intensity to form a pattern. .
Here, the positive developer is a developer that selectively dissolves and removes the exposed portion that is equal to or higher than the predetermined threshold shown by the solid line in FIG. 1. The negative developer is lower than the predetermined threshold. A developer that selectively dissolves and removes the exposed portion. The development process using a positive developer is referred to as positive development (also referred to as a positive development process), and the development process using a negative developer is referred to as a negative development (also referred to as a negative development process). Call.

On the other hand, Patent Document 2 discloses a double development technique as a double patterning technique for increasing resolution. In this example, a general chemical amplification image forming method is used, and by exposure, the polarity of the resin in the resist composition becomes high in a region where the light intensity is high, and low in a region where the light intensity is low. By utilizing this, positive development is performed by dissolving a high exposure area of a specific resist film in a high polarity developer, and negative development is performed by dissolving a low exposure area in a low polarity developer. . Specifically, as shown in FIG. 2, a region where the exposure amount E2 of the irradiation light 1 is dissolved using an alkaline aqueous solution as a positive developer, and a region where the exposure amount E1 is less than a specific organic solvent is negatively developed. It is dissolved as a liquid. As a result, as shown in FIG. 2, an intermediate exposure amount (E2-E1) region remains without being developed, and an L / S pattern 3 having a half pitch of the exposure mask 2 is formed on the wafer 4. Yes.
However, it is very difficult to select an optimal combination of a resist composition and a negative developer, and in the above example, developability when using a negative developer is deteriorated. There was a problem.
Further, when a fine pattern is formed by double development, it is not sufficient that the resolving power when using a negative developer or a positive developer alone is sufficient, and the negative developer and the positive developer are not sufficient. In either case, it has been required to exhibit good pattern resolution.

In view of the above problems, pattern formation using a positive resist composition in which the solubility in a positive developer is increased and the solubility in a negative developer is decreased by irradiation with actinic rays or radiation in the double development technique. A method is proposed in US Pat. According to this technique, it is said that a highly accurate fine pattern can be stably obtained.
However, it is required that a fine pattern with higher accuracy can be stably obtained by being excellent in line width variation (LWR), exposure latitude (EL), and focus margin (DOF).

JP 2006-156422 A JP 2000-199953 A US Patent Application Publication No. 2008/0187860

  The present invention solves the above-mentioned problems, and in order to more stably form a high-precision fine pattern for manufacturing a highly integrated and high-precision electronic device, line width variation (LWR), exposure latitude (EL) It is another object of the present invention to provide a negative developing resist composition having excellent focus margin (DOF), a pattern forming method using the same, a resist film and a pattern.

  The present invention has the following configuration, whereby the above object of the present invention is achieved.

  (1) (A) a resin having an acid-decomposable repeating unit, which increases in polarity by the action of an acid and decreases in solubility in a negative developer, and (B) the following general formula by irradiation with actinic rays or radiation A negative developing resist composition comprising a photoacid generator for generating an acid represented by (I).

式中、
Ｘｆは、それぞれ独立に、フッ素原子、又は少なくとも１つのフッ素原子で置換されたアルキル基を表す。
Ｒ_１、Ｒ_２は、それぞれ独立に、水素原子、フッ素原子、アルキル基、及び、少なくとも１つのフッ素原子で置換されたアルキル基から選ばれる基を表し、複数存在する場合のＲ_１、Ｒ_２は、それぞれ同一でも異なっていてもよい。ただし、Ｒ_１及びＲ_２の少なくとも一方は、水素原子又はアルキル基を表す。
Ｌは、二価の連結基を表し、該二価の連結基は、―ＣＯＯ−、−ＯＣＯ−、−ＣＯ−、−Ｏ−、−Ｓ―、−ＳＯ―、アルキレン基、シクロアルキレン基又はアルケニレン基である。複数存在する場合のＬは同一でも異なっていてもよい。
Ａは、環状構造を有する基を表す。
ｘは１〜２０の整数を表し、ｙは０〜１０の整数を表し、ｚは０〜１０の整数を表す。

Where
Xf each independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom.
R ₁ and R ₂ each independently represents a hydrogen atom, a fluorine atom, an alkyl group, or a group selected from an alkyl group substituted with at least one fluorine atom, and R ₁ and R ₂ in the case where a plurality of R ₁ and R _{2 are present.} May be the same or different. However, at least one of R ₁ and R ₂ represents a hydrogen atom or an alkyl group.
L represents a divalent linking group, and the divalent linking group is —COO—, —OCO—, —CO—, —O—, —S—, —SO—, an alkylene group, a cycloalkylene group, or Alkenylene group. When there are a plurality of L, they may be the same or different.
A represents a group having a cyclic structure.
x represents an integer of 1 to 20, y represents an integer of 0 to 10, and z represents an integer of 0 to 10.

  (2) The negative developing resist composition as described in (1), wherein the acid represented by the general formula (I) is an acid represented by the following general formula (II) or (III): object.

  (3) In (2), the acid represented by the general formula (II) or (III) is an acid represented by the general formula (II) and having two fluorine atoms. The negative developing resist composition as described.

  (4) The negative developing resist composition as described in (1) or (2), wherein A in the acids represented by the general formulas (I) to (III) does not contain a fluorine atom.

  (5) The negative according to any one of (1) to (4), wherein in the general formulas (I), (II) and (III), the cyclic structure in A has 5 or more carbon atoms. Resist composition for mold development.

  (6) The negative developing resist composition as described in any one of (1) to (5) above, wherein the group having a cyclic structure as A is a cyclic group.

  (7) (a) Using the negative developing resist composition according to any one of (1) to (6), (i) an exposure step, and (d) using a negative developer. And a developing process.

  (8) The negative developer is a developer containing at least one solvent selected from ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents. The pattern formation method as described in (7).

  (9) The resin is a resin whose polarity is increased by the action of an acid to increase the solubility in a positive developer, and (c) further includes a step of developing using a positive developer. (7) The pattern formation method as described in (8).

  (10) The pattern forming method according to any one of (7) to (9), wherein the exposure in the exposure step (A) is immersion exposure.

  (11) A resist film formed from the negative developing resist composition according to any one of (1) to (6).

  (12) A pattern formed by the pattern forming method according to any one of (7) to (9).

  According to the present invention, a negative developing resist composition excellent in line width variation (LWR), exposure latitude (EL), and focus margin (DOF), a pattern forming method using the same, a resist film and a pattern are provided. Can do.

It is a schematic diagram showing the relationship between the positive development, the negative development and the exposure amount in the conventional method. It is a schematic diagram showing a pattern forming method using both positive development and negative development. It is a schematic diagram which shows the relationship between positive image development, negative image development, and exposure amount. It is the graph which showed the relationship between the exposure amount at the time of using a positive developing solution or a negative developing solution, and a residual film curve. It is a schematic diagram showing the relationship between the positive development, the negative development and the exposure amount in the method of the present invention. It is a schematic diagram showing the relationship between the positive development, the negative development and the exposure amount in the method of the present invention. It is a schematic diagram showing the relationship between the positive development, the negative development and the exposure amount in the method of the present invention. It is drawing which shows the spatial intensity distribution of an optical image. It is a schematic diagram which shows the relationship between positive image development, threshold value (a), and light intensity. It is a schematic diagram which shows the spatial intensity distribution of an optical image. It is a schematic diagram which shows the relationship between negative image development, a threshold value (b), and light intensity.

Hereinafter, modes for carrying out the present invention will be described.
In addition, in the description of the group (atomic group) in this specification, the description which does not describe substitution and non-substitution includes the thing which has a substituent with the thing which does not have a substituent. . For example, the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).
“Actinic light” or “radiation” in the present specification means, for example, an emission line spectrum of a mercury lamp, far ultraviolet rays represented by an excimer laser, extreme ultraviolet rays (EUV light), X-rays, electron beams and the like. In the present invention, light means actinic rays or radiation.
In addition, the term “exposure” in the present specification is not limited to exposure with far ultraviolet rays such as mercury lamps and excimer lasers, X-rays, EUV light, etc., but also particle beams such as electron beams and ion beams, unless otherwise specified. Include drawing in exposure.

  First, terms used in this specification will be described. There are two types of pattern formation methods: positive and negative. Both use the fact that the solubility of the resist film in the developer changes due to a chemical reaction triggered by light irradiation. The case where the part is dissolved in the developer is called a positive type, and the case where the non-irradiated part is dissolved in the developer is called a negative type. There are two types of developers used in this case, a positive developer and a negative developer. The positive developer is a developer that selectively dissolves and removes the exposed portion above the predetermined threshold indicated by the solid line in FIG. 1, and the negative developer selects the exposed portion below the predetermined threshold. It is a developer that is dissolved and removed. The development process using a positive developer is referred to as positive development (also referred to as a positive development process), and the development process using a negative developer is referred to as a negative development (also referred to as a negative development process). Call. Multiple development (also referred to as multiple development process) is a development system that combines a development process using the positive developer and a development process using the negative developer. In the present invention, the resist composition used for negative development is called a negative development resist composition, and the resist composition used for multiple development is called a multiple development resist composition. Hereinafter, when it is simply described as a resist composition, it means a negative developing resist composition. The negative type rinsing liquid represents a rinsing liquid containing an organic solvent, which is used in the washing step after the negative type developing step.

  In the present invention, as a technique for increasing the resolving power, as shown in FIG. 3, a developer (negative developer) that selectively dissolves and removes an exposed portion having a predetermined threshold value (b) or less, and a polarity by the action of an acid. Increases the solubility in a positive developer (preferably an alkali developer) and decreases the solubility in a negative developer (preferably an organic developer) by irradiation with actinic rays or radiation. A new pattern forming method is proposed in combination with a negative developing resist composition for forming a film.

The negative development resist composition of the present invention exhibits excellent development characteristics even with respect to a developer (positive developer) that selectively dissolves and removes an exposed area having a predetermined threshold value (a) or more. Developer (positive developer) that selectively dissolves / removes exposed portions that are equal to or higher than the threshold value (a) and developer solution that selectively dissolves / removes exposed portions that are equal to or lower than a predetermined threshold (b) (negative development). (Liquid) and a resist composition for negative development can be combined to form a pattern by multiple development.
That is, as shown in FIG. 3, when a pattern element on an exposure mask is projected onto a wafer by light irradiation, a region having a high light irradiation intensity (an exposed portion having a predetermined threshold value (a) or more) is positively positioned. An optical aerial image (light) is obtained by dissolving / removing with a mold developer and dissolving / removing an area with a low light irradiation intensity (exposed portion below a predetermined threshold (b)) with a negative developer. A pattern having a resolution twice the frequency of the intensity distribution can be obtained.

  Therefore, the negative developing resist composition of the present invention can be suitably used as a multiple developing resist composition.

A pattern forming process necessary for carrying out the present invention includes the following steps.
(A) (A) a resin having an acid-decomposable repeating unit, which increases in polarity by the action of an acid and decreases in solubility in a negative developer, and (B) is detailed later by irradiation with actinic rays or radiation. A step of forming a film with a negative developing resist composition comprising a photoacid generator for generating an acid represented by the general formula (I), and (C) a solvent;
(A) an exposure process;
(D) a pattern forming method comprising a step of developing using a negative developer.

  In the pattern forming method of the present invention, the negative developer is a developer containing at least one solvent selected from a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent, and an ether solvent. It is preferable.

  In the pattern forming method of the present invention, the resin is a resin whose polarity is increased by the action of an acid and the solubility in a positive developer is increased, and (c) further includes a step of developing using a positive developer. It is preferable.

  The pattern forming method of the present invention preferably further includes (f) a step of washing using a rinse solution containing an organic solvent.

  The pattern forming method of the present invention preferably includes (e) a heating step after (b) the exposure step.

  The pattern formation method of this invention can have (b) exposure process in multiple times.

  The pattern formation method of this invention can have (e) a heating process in multiple times.

The resist film of the present invention is formed from the negative developing resist composition of the present invention.
The pattern of the present invention is formed by the pattern forming method of the present invention.

To carry out the present invention, (A) a resin having an acid-decomposable repeating unit, whose polarity is increased by the action of an acid and whose solubility in a negative developer is decreased, and (B) irradiation with actinic rays or radiation A negative-type developing resist composition comprising a photoacid generator that generates an acid represented by formula (I), which will be described in detail later, and (Ab) a negative-type developer ( Preferably, an organic developer) is required.
In order to carry out the present invention, it is further preferred to use (Ac) positive developer (preferably an alkali developer).
In order to carry out the present invention, it is preferable to use a negative developing rinse solution containing (Ad) an organic solvent.

  In the case of performing a pattern formation process using two types of developer, a positive developer and a negative developer, the order of development is not particularly limited, but after the first exposure, the positive developer or the negative developer is used. It is preferable to perform development using a mold developer, and then to perform negative or positive development with a developer different from the first development. Furthermore, after performing negative development, it is preferable to wash with a negative developing rinse containing an organic solvent.

As a method of forming a pattern, there are (a) a method using a chemical reaction such as polarity conversion, and (b) a method using a bond formation between molecules such as a crosslinking reaction and a polymerization reaction.
In resist material systems where the molecular weight of the resin increases due to intermolecular bonds such as cross-linking reactions and polymerization reactions, one resist material is positive for one developer and one for another developer. It was difficult to construct a system that would act on the negative type.

According to the present invention, one resist composition can simultaneously act as a positive type for a positive developer and as a negative type for a negative developer.
In the present invention, an alkaline developer (aqueous) can be used as the positive developer, and an organic developer containing an organic solvent can be used as the negative developer.
In addition, the resist composition contains a resin whose polarity is increased by the action of an acid, and a film whose solubility in a negative developer is decreased and the solubility in a positive developer is increased by irradiation with actinic rays or radiation. It is a “resin composition that forms”.
According to the resist composition of the present invention, it contains a resin whose polarity is increased by the action of an acid, and not only the solubility in a negative developer is reduced by irradiation with actinic rays or radiation, It is possible to simultaneously increase the solubility in the developer and reduce the solubility in the developer containing the organic solvent.

In the present invention, it is important to control the “threshold” of the exposure amount (the exposure amount at which the film is solubilized or insolubilized in the developer in the light irradiation region). That is, when performing pattern formation, the minimum exposure amount that is solubilized in the positive developer and the minimum exposure amount that is insoluble in the negative developer so that a desired line width is obtained is the “threshold value”. It is.
The “threshold value” can be obtained as follows.
That is, when performing pattern formation, the minimum exposure amount solubilized in a positive developer and the minimum exposure amount insoluble in a negative developer are threshold values so that a desired line width can be obtained. .
More precisely, the threshold value is defined as follows.
When the residual film ratio with respect to the exposure amount of the resist film is measured, as shown in FIG. 4, the exposure amount at which the residual film ratio becomes 0% with respect to the positive developer, the threshold value (a), and the negative developer. On the other hand, an exposure amount at which the remaining film rate becomes 100% is defined as a threshold value (b).
For example, as shown in FIG. 5, by setting the exposure threshold (a) solubilized in a positive developer higher than the exposure threshold (b) solubilized in a negative developer, 1 A pattern can be formed by one exposure. That is, as shown in FIG. 6, first, a resist is applied to a wafer, and exposure is performed. First, a positive developing solution dissolves the exposure amount threshold (a) or more, and then a negative developing solution is used to expose the exposure amount threshold. (B) A pattern can be formed by one exposure by dissolving the following. In this case, the order of development with a positive developer and development with a negative developer may be first. After negative development, if a rinse solution containing an organic solvent is used for cleaning, a better pattern can be formed.

As a method for controlling the threshold value, there are a method for controlling a material-related parameter of the resist composition and the developer and a parameter related to the process.
As the material-related parameters, it is effective to control various physical property values related to the solubility of the resist composition in the developer and the organic solvent, that is, SP value (solubility parameter), LogP value, and the like. Specifically, the polymer weight average molecular weight, molecular weight dispersity, monomer composition ratio, monomer polarity, monomer sequence, polymer blend, addition of low molecular additives, and the developer contained in the resist composition, There are developer concentration, addition of low molecular additives, addition of surfactants, and the like.
Process-related parameters include film formation temperature, film formation time, post-exposure post-heating temperature, time, development temperature, development time, developing device nozzle method (liquid filling method), post-development rinsing method Etc.
Therefore, in the pattern formation method using negative development and the pattern formation method by multiple development using both negative development and positive development, in order to obtain a good pattern, the above-mentioned material-related parameters and process parameters are appropriate. It is important to control and combine them.

  The pattern formation process using two types of developer, a positive developer and a negative developer, may be performed by a single exposure as described above, or may be performed by a process of performing two or more exposures. Good. That is, after performing the first exposure, development is performed using a positive developer or a negative developer, and then, after performing the second exposure, with a developer different from the first development, Performs negative or positive development.

As an advantage of performing exposure twice or more, there is an advantage that the degree of freedom in controlling the threshold value in the development after the first exposure and the control of the threshold value in the development after the second exposure is increased. When performing the exposure twice or more, it is desirable to make the second exposure amount larger than the first exposure amount. As shown in FIG. 7, in the second development, the threshold value is determined based on the sum of the first and second exposure amount histories, but the second exposure amount is the first exposure amount. This is because if the amount is sufficiently larger than the amount, the influence of the first exposure amount becomes small and can be ignored in some cases.
Exposure at the first step of performing exposure ^{(Eo1 [mJ / cm 2]} ) , the exposure amount in the step of performing the second exposure ^{(Eo2 [mJ / cm 2]} ) than, 5 [mJ / cm ^2] or more Smaller is desirable. This can reduce the influence of the history of the first exposure on the pattern forming process by the second exposure.

  In order to change the exposure amount for the first time and the exposure amount for the second time, the above-described method of adjusting various parameters of the material / process is effective. In particular, the temperature of the first heating step and 2 It is effective to control the temperature of the second heating step. That is, in order to make the first exposure amount smaller than the second exposure amount, it is effective to set the temperature of the first heating step higher than the temperature of the second heating step.

The threshold value (a) in the positive development corresponds to the following in the actual lithography process.
After forming a film with a resist composition on a substrate that is irradiated with actinic rays or radiation, the solubility in a positive developer increases and the solubility in a negative developer decreases. Exposure is performed through a photomask having a pattern size. At this time, exposure is performed while swinging the focus of exposure (focus) in increments of 0.05 [μm] and the exposure amount in increments of 0.5 [mJ / cm ² ]. After the exposure, heating is performed at a desired temperature for a desired time, and development is performed for a desired time with an alkali developer having a desired concentration. After development, the line width of the pattern is measured using a CD-SEM, and the exposure amount A [mJ / cm ² ] and the focus position for forming the desired line width are determined. Next, the intensity distribution of the optical image when the previous photomask is irradiated at the specific exposure amount A [mJ / cm ² ] and the specific focus position is calculated. The calculation can be performed using simulation software (Prolith ver. 92.0.15 manufactured by KLA). Details of the calculation method are described in Inside PROLITH (by Chris. A. Mack, FINLE Technologies, Inc., Chapter2 Aerial Image Formation).
As an example of the calculation result, a spatial intensity distribution of an optical image as shown in FIG. 8 is obtained.

  Here, as shown in FIG. 9, the light intensity at the position where the spatial position is shifted from the minimum value of the spatial intensity distribution of the optical image by a half of the obtained pattern line width becomes the threshold value (a). Correspond.

The threshold value (b) in the negative development corresponds to the following in the actual lithography process.
A film made of a resist composition containing a resin whose polarity is increased by the action of an acid on a substrate, and increasing the solubility in a positive developer and reducing the solubility in a negative developer by irradiation with actinic rays or radiation. Then, exposure is performed through a photomask having a desired pattern size under desired illumination conditions. At this time, exposure is performed while swinging the focus of exposure (focus) in increments of 0.05 [μm] and the exposure amount in increments of 0.5 [mJ / cm ² ]. After the exposure, heating is performed at a desired temperature for a desired time, and development is performed for a desired time with an organic developer having a desired concentration. After development, the line width of the pattern is measured using a CD-SEM, and the exposure amount A [mJ / cm ² ] and the focus position for forming the desired line width are determined. Next, the intensity distribution of the optical image when the previous photomask is irradiated at the specific exposure amount A [mJ / cm ² ] and the specific focus position is calculated. The calculation is performed using simulation software (Prolith manufactured by KLA).
For example, a spatial intensity distribution of an optical image as shown in FIG. 10 is obtained.

  Here, as shown in FIG. 11, the light intensity at the position where the spatial position is shifted from the maximum value of the spatial intensity distribution of the optical image by 1/2 of the obtained pattern line width is defined as the threshold (b). .

The threshold (a) is preferably 0.1 to 100 [mJ / cm ² ], more preferably 0.5 to 50 [mJ / cm ² ], and still more preferably 1 to 30 [mJ / cm ^2]. ]. The threshold value (b) is preferably 0.1 to 100 [mJ / cm ² ], more preferably 0.5 to 50 [mJ / cm ² ], and still more preferably 1 to 30 [mJ / cm ^2]. ]. The difference between the threshold values (a) and (b) is preferably 0.1 to 80 [mJ / cm ² ], more preferably 0.5 to 50 [mJ / cm ² ], and still more preferably 1 It is -30 [mJ / cm < ² >].

In the present invention, the film formed on the substrate comprises (A) a resin having an acid-decomposable repeating unit, an increase in polarity by the action of an acid and a decrease in solubility in a negative developer, and (B) A negative resist composition comprising a photoacid generator that generates an acid represented by formula (I), which will be described in detail later, upon irradiation with actinic rays or radiation, and (C) a solvent. It is a film formed by applying an object.
Hereinafter, the resist composition that can be used in the present invention will be described.

(A) Resin having an acid-decomposable repeating unit that increases in polarity by the action of an acid and decreases in solubility in a negative developer. The resin used in the resist composition of the present invention has an increased polarity by the action of an acid. Examples of the resin whose solubility in the negative developer is decreased include, for example, a group (hereinafter referred to as an alkali-soluble group) that decomposes into the main chain or side chain of the resin or both the main chain and the side chain by the action of an acid. A resin having an “acid-decomposable group” (hereinafter also referred to as “acid-decomposable resin” or “resin (A)”), and the polarity of this resin is increased by the action of an acid. Thus, it is also a resin whose solubility in a positive developer (particularly an alkali developer) is increased.
As the resin (A), a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure, an increase in polarity by the action of an acid, an increase in solubility in an alkali developer, and a decrease in solubility in an organic solvent ( Hereinafter, it is also referred to as “alicyclic hydrocarbon-based acid-decomposable resin”).
The reason for this is not clear, but it is likely that the positive polarity developer (preferably an alkali developer) and the negative developer (preferably, the polarities of the resin significantly change before and after irradiation with actinic rays or radiation. It is considered that the dissolution contrast is improved when developed using an organic solvent. Furthermore, a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure has high hydrophobicity, and a negative developer (preferably an organic solvent) is used to develop a region of the resist film with low light irradiation intensity. It is considered that the developability in the case is improved.

  The negative resist composition for development according to the present invention containing the resin (A) can be suitably used for irradiation with ArF excimer laser light.

The acid-decomposable resin has a repeating unit having an acid-decomposable group.
A preferable group as the acid-decomposable group is a group in which a hydrogen atom of an alkali-soluble group is substituted with a group capable of leaving with an acid.
Alkali-soluble groups include phenolic hydroxyl groups, carboxyl groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, (alkylsulfonyl) (alkylcarbonyl) imides. Group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris (alkylsulfonyl) methylene group And the like.
Preferred alkali-soluble groups include carboxyl groups, fluorinated alcohol groups (preferably hexafluoroisopropanol groups), and sulfonic acid groups.
As the acid eliminable group, there can be, for _{example, -C (R 36) (R} 37) (R 38), - C (R 36) (R 37) (OR 39), - C (R 01) (R 02 ) (OR ₃₉ ) and the like.
In the formula, R _{36 to} R ₃₉ each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. R ₃₆ and R ₃₇ may be bonded to each other to form a ring.
R _{01 to} R ₀₂ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
The acid-decomposable group is preferably a cumyl ester group, an enol ester group, an acetal ester group, a tertiary alkyl ester group or the like. More preferably, it is a tertiary alkyl ester group.

  The alicyclic hydrocarbon-based acid-decomposable resin includes a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pV) and the following general formula (II-AB). A resin having at least one selected from the group of repeating units shown is preferred.

In general formulas (pI) to (pV),
R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a sec-butyl group, and Z is an atom necessary for forming a cycloalkyl group together with a carbon atom. Represents a group.
R _{12 to} R ₁₆ each independently represents a linear or branched alkyl group or cycloalkyl group having 1 to 4 carbon atoms. However, at least one of R _{12 to} R ₁₄ , or any of R ₁₅ and R ₁₆ represents a cycloalkyl group.
R _{17 to} R ₂₁ each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group. However, at least one of R _{17 to} R ₂₁ represents a cycloalkyl group. Moreover, either R <_19> , R < ₂₁ > represents a C1-C4 linear or branched alkyl group or cycloalkyl group.
R _{22 to} R ₂₅ each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group. However, at least one of R _{22 to} R ₂₅ represents a cycloalkyl group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

In general formula (II-AB),
R ₁₁ ′ and R ₁₂ ′ each independently represents a hydrogen atom, a cyano group, a halogen atom or an alkyl group.
Z ′ represents an atomic group for forming an alicyclic structure containing two bonded carbon atoms (C—C).

  The general formula (II-AB) is more preferably the following general formula (II-AB1) or general formula (II-AB2).

In the formulas (II-AB1) and (II-AB2),
R ₁₃ ′ to R ₁₆ ′ each independently represents a hydrogen atom, a halogen atom, a cyano group, —COOH, —COOR ₅ , an acid-decomposable group, —C (═O) —XA′—R ₁₇ ′, An alkyl group or a cycloalkyl group is represented. At least two members out of R ₁₃ ′ to R ₁₆ ′ may combine to form a ring.
Here, R ₅ represents an alkyl group, a cycloalkyl group, or a group having a lactone structure.
X represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or an -NHSO ₂ NH-.
A ′ represents a single bond or a divalent linking group.
R ₁₇ ′ represents —COOH, —COOR ₅ , —CN, a hydroxyl group, an alkoxy group, —CO—NH—R ₆ , —CO—NH—SO ₂ —R ₆ or a group having a lactone structure.
R ₆ represents an alkyl group or a cycloalkyl group.
n represents 0 or 1.

In the general formulas (pI) to (pV), as the linear or branched alkyl group having 1 to 4 carbon atoms in R _{12 to} R ₂₅ , for example, a methyl group, an ethyl group, an n-propyl group, Examples include isopropyl group, n-butyl group, isobutyl group, sec-butyl group and the like.

The cycloalkyl group or the cycloalkyl group formed by Z and the carbon atom in R _{12 to} R ₂₅ may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These cycloalkyl groups may have a substituent.

  Preferred cycloalkyl groups include adamantyl group, noradamantyl group, decalin residue, tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, A cyclodecanyl group and a cyclododecanyl group can be mentioned. More preferable examples include an adamantyl group, norbornyl group, cyclohexyl group, cyclopentyl group, tetracyclododecanyl group, and tricyclodecanyl group.

  As further substituents of these alkyl groups and cycloalkyl groups, alkyl groups (1 to 4 carbon atoms), halogen atoms, hydroxyl groups, alkoxy groups (1 to 4 carbon atoms), carboxyl groups, alkoxycarbonyl groups (carbon numbers) 2-6). Examples of the substituent that the alkyl group, alkoxy group, alkoxycarbonyl group and the like may further have include a hydroxyl group, a halogen atom, and an alkoxy group.

  The structures represented by the general formulas (pI) to (pV) can be used for protecting alkali-soluble groups. Examples of the alkali-soluble group include various groups known in this technical field.

  Specific examples include a structure in which a hydrogen atom of a carboxyl group, a sulfonic acid group, a phenolic hydroxyl group, or a thiol group is substituted with a structure represented by the general formulas (pI) to (pV), preferably a carboxyl group The hydrogen atom of the sulfonic acid group is substituted with the structure represented by the general formulas (pI) to (pV).

  As the repeating unit having an alkali-soluble group protected by the structure represented by the general formulas (pI) to (pV), a repeating unit represented by the following general formula (pA) is preferable.

Here, each R independently represents a hydrogen atom, a halogen atom, or a linear or branched alkyl group having 1 to 4 carbon atoms. A plurality of R may be the same or different.
A represents a single bond, an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, or a urea group, or a combination of two or more groups. Represents. A single bond is preferable.
Rp ₁ represents any group of the above formulas (pI) to (pV).

  The repeating unit represented by the general formula (pA) is particularly preferably a repeating unit composed of 2-alkyl-2-adamantyl (meth) acrylate and dialkyl (1-adamantyl) methyl (meth) acrylate.

  Hereinafter, although the specific example of the repeating unit which has an acid-decomposable group is shown, this invention is not limited to this.

Examples of the halogen atom in the general formula (II-AB), R ₁₁ ′, and R ₁₂ ′ include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.

Examples of the alkyl group in R ₁₁ ′ and R ₁₂ ′ include a linear or branched alkyl group having 1 to 10 carbon atoms.

  The atomic group for forming the alicyclic structure of Z ′ is an atomic group that forms a repeating unit of an alicyclic hydrocarbon which may have a substituent in a resin, and among them, a bridged type alicyclic group. An atomic group for forming a bridged alicyclic structure forming a cyclic hydrocarbon repeating unit is preferred.

Examples of the skeleton of the alicyclic hydrocarbon formed include those similar to the alicyclic hydrocarbon groups of R _{12 to} R _{25 in} the general formulas (pI) to (pV).

The alicyclic hydrocarbon skeleton may have a substituent. Examples of such a substituent include R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or (II-AB2).

  In the alicyclic hydrocarbon-based acid-decomposable resin, the group decomposed by the action of an acid is a repeating unit having a partial structure containing the alicyclic hydrocarbon represented by the general formula (pI) to the general formula (pV), It can contain in at least 1 sort (s) of a repeating unit represented by general formula (II-AB), and the repeating unit of a postscript copolymerization component. The group capable of decomposing by the action of an acid is preferably contained in a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by general formula (pI) to general formula (pV).

Various substituents of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or the general formula (II-AB2) are atomic groups for forming an alicyclic structure in the general formula (II-AB). It can also be a substituent of the atomic group Z ′ for forming a bridged alicyclic structure.

  Specific examples of the repeating unit represented by the general formula (II-AB1) or (II-AB2) include the following specific examples, but the present invention is not limited to these specific examples.

  The alicyclic hydrocarbon-based acid-decomposable resin preferably has a lactone group. As the lactone group, any group having a lactone structure can be used, but a group having a 5- to 7-membered ring lactone structure is preferred, and a bicyclo structure or spiro is added to the 5- to 7-membered ring lactone structure. Those in which other ring structures are condensed to form a structure are preferred. It is more preferable to have a repeating unit having a group having a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-17). Further, a group having a lactone structure may be directly bonded to the main chain. Preferred lactone structures are represented by the general formulas (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), (LC1-14), and (LC1-17). By using a specific lactone structure, line edge roughness and development defects are improved.

The lactone structure portion may or may not have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 2 to 8 carbon atoms, and a carboxyl group. , Halogen atom, hydroxyl group, cyano group, acid-decomposable group and the like. n ₂ represents an integer of 0-4. When n ₂ is 2 or more, a plurality of substituents (Rb ₂ ) may be the same or different, and a plurality of substituents (Rb ₂ ) may be bonded to form a ring. .

As the repeating unit having a group having a lactone structure represented by any of the general formulas (LC1-1) to (LC1-17), R _{13 in the} above general formula (II-AB1) or (II-AB2) may be used. A group in which at least one of 'to R ₁₆ ' has a group represented by general formula (LC1-1) to (LC1-17) (for example, R _{5 of} -COOR ₅ is represented by general formula (LC1-1) to (LC1) -17) or a repeating unit represented by the following general formula (AI).

In general formula (AI),
Rb ₀ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms.
Preferable substituents that the alkyl group of Rb ₀ may have include a hydroxyl group and a halogen atom.
Examples of the halogen atom for Rb ₀ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Rb ₀ is preferably a hydrogen atom, a methyl group or a trifluoromethyl group, particularly preferably a hydrogen atom or a methyl group.
Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent group obtained by combining these. A linking group represented by a single bond or -Ab ₁ -CO _2- is preferable. Ab ₁ is a linear or branched alkylene group, a monocyclic or polycyclic cycloalkylene group, and preferably a methylene group, an ethylene group, a cyclohexylene group, an adamantylene group, or a norbornylene group.
V represents a group represented by any one of the general formulas (LC1-1) to (LC1-17).

  The repeating unit having a lactone structure usually has an optical isomer, but any optical isomer may be used. One optical isomer may be used alone, or a plurality of optical isomers may be mixed and used. When one kind of optical isomer is mainly used, the optical purity (ee) thereof is preferably 90% or more, more preferably 95% or more.

Specific examples of the repeating unit having a group having a lactone structure are given below, but the present invention is not limited thereto. In specific examples, Rx represents H, CH ₃ , CH ₂ OH, or CF ₃ .

The alicyclic hydrocarbon-based acid-decomposable resin preferably has a repeating unit having an organic group having a polar group, particularly a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group. This improves the substrate adhesion and developer compatibility. The alicyclic hydrocarbon structure of the alicyclic hydrocarbon structure substituted with a polar group is preferably an adamantyl group, a diamantyl group, or a norbornane group. The polar group is preferably a hydroxyl group or a cyano group.
As the alicyclic hydrocarbon structure substituted with a polar group, partial structures represented by the following general formulas (VIIa) to (VIId) are preferable.

In general formulas (VIIa) to (VIIc),
R _{2c to} R _4c each independently represents a hydrogen atom, a hydroxyl group or a cyano group. However, at least one of R _{2c to} R _4c represents a hydroxyl group or a cyano group. Preferably, one or two of R _{2c to} R _4c are a hydroxyl group and the remainder is a hydrogen atom.
In general formula (VIIa), it is more preferable that two of R _{2c to} R _4c are a hydroxyl group and the remaining is a hydrogen atom.

As the repeating unit having a group represented by the general formulas (VIIa) to (VIId), at least one of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-AB1) or (II-AB2) is the above. Those having groups represented by general formulas (VIIa) to (VIId) (for example, R ₅ in —COOR ₅ represents groups represented by general formulas (VIIa) to (VIId)) or the following general formula (AIIa) ) To (AIId).

In general formulas (AIIa) to (AIId),
R _1c represents a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.
R _<2c > -R < _4c > is synonymous with R < _2c > -R < _4c > in general formula (VIIa)-(VIIc).

  Specific examples of the repeating units represented by the general formulas (AIIa) to (AIId) are given below, but the present invention is not limited thereto.

  The alicyclic hydrocarbon-based acid-decomposable resin may have a repeating unit represented by the following general formula (VIII).

In general formula (VIII):
Z ₂ represents —O— or —N (R ₄₁ ) —. R ₄₁ represents a hydrogen atom, a hydroxyl group, an alkyl group, or —OSO ₂ —R ₄₂ . R ₄₂ represents an alkyl group, a cycloalkyl group or a camphor residue. The alkyl group of R ₄₁ and R ₄₂ may be substituted with a halogen atom (preferably a fluorine atom) or the like.

  Examples of the repeating unit represented by the general formula (VIII) include the following specific examples, but the present invention is not limited thereto.

  The alicyclic hydrocarbon-based acid-decomposable resin preferably has a repeating unit having an alkali-soluble group, and more preferably has a repeating unit having a carboxyl group. By having this, the resolution in contact hole applications increases. The repeating unit having a carboxyl group includes a repeating unit in which a carboxyl group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid or methacrylic acid, or a carboxyl group in the main chain of the resin through a linking group. Either a repeating unit that is bonded, or a polymerization initiator or chain transfer agent having an alkali-soluble group is introduced at the end of the polymer chain during polymerization, and the linking group is a monocyclic or polycyclic hydrocarbon. You may have a structure. Particularly preferred are repeating units of acrylic acid or methacrylic acid.

  The alicyclic hydrocarbon-based acid-decomposable resin may further have a repeating unit having 1 to 3 groups represented by the following general formula (F1). This improves line edge roughness performance.

In general formula (F1),
R _{50 to} R ₅₅ each independently represent a hydrogen atom, a fluorine atom or an alkyl group. However, at least one of R _{50 to} R ₅₅ represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
Rxa represents a hydrogen atom or an organic group (preferably an acid-decomposable protective group, an alkyl group, a cycloalkyl group, an acyl group, or an alkoxycarbonyl group).

The alkyl group of R _{50 to} R ₅₅ may be substituted with a halogen atom such as a fluorine atom, a cyano group, or the like, and preferably an alkyl group having 1 to 3 carbon atoms, such as a methyl group or a trifluoromethyl group. be able to.
R _{50 to} R ₅₅ are preferably all fluorine atoms.

  Examples of the organic group represented by Rxa include an acid-decomposable protecting group and an optionally substituted alkyl group, cycloalkyl group, acyl group, alkylcarbonyl group, alkoxycarbonyl group, alkoxycarbonylmethyl group, alkoxymethyl group. , 1-alkoxyethyl group is preferable.

  The repeating unit having a group represented by the general formula (F1) is preferably a repeating unit represented by the following general formula (F1a).

In general formula (F1a),
Rx represents a hydrogen atom, a halogen atom or an alkyl group (preferably having 1 to 4 carbon atoms). Preferable substituents that the alkyl group of Rx may have include a hydroxyl group and a halogen atom.
Fa represents a single bond or a linear or branched alkylene group, preferably a single bond.
Fb represents a monocyclic or polycyclic hydrocarbon group.
Fc represents a single bond or a linear or branched alkylene group (preferably a single bond or a methylene group).
F ₁ represents a group represented by the general formula (F1).
p ₁ is an integer of 1 to 3.
The cyclic hydrocarbon group in Fb is preferably a cyclopentylene group, a cyclohexylene group, or a norbornylene group.

  Specific examples of the repeating unit having a group represented by the general formula (F1) are shown below, but the present invention is not limited thereto.

The alicyclic hydrocarbon-based acid-decomposable resin may further have a repeating unit that has an alicyclic hydrocarbon structure and does not exhibit acid-decomposability. This can reduce the elution of low molecular components from the resist film to the immersion liquid during immersion exposure.
Specifically, the alicyclic hydrocarbon-based acid-decomposable resin preferably further contains a repeating unit represented by the general formula (III) that has neither a hydroxyl group nor a cyano group.

In general formula (III), R ₅ represents a hydrocarbon group having at least one cyclic structure and having neither a hydroxyl group nor a cyano group.
Ra represents a hydrogen atom, an alkyl group, or a —CH ₂ —O—Ra ₂ group. In the formula, Ra ₂ represents an alkyl group or an acyl group. Examples of Ra include a hydrogen atom, a methyl group, or a trifluoromethyl group.

The cyclic structure possessed by R ₅ includes a monocyclic hydrocarbon group and a polycyclic hydrocarbon group. Examples of the monocyclic hydrocarbon group include cycloalkenyl having 3 to 12 carbon atoms such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and the like, and cycloalkyl groups having 3 to 12 carbon atoms and cyclohexenyl group. Groups. Preferable monocyclic hydrocarbon groups are monocyclic hydrocarbon groups having 3 to 7 carbon atoms, and more preferable examples include a cyclopentyl group and a cyclohexyl group.

The polycyclic hydrocarbon group includes a ring assembly hydrocarbon group and a bridged cyclic hydrocarbon group, and examples of the ring assembly hydrocarbon group include a bicyclohexyl group and a perhydronaphthalenyl group. As the bridged cyclic hydrocarbon ring, for example, bicyclic such as pinane, bornane, norpinane, norbornane, bicyclooctane ring (bicyclo [2.2.2] octane ring, bicyclo [3.2.1] octane ring, etc.) Hydrocarbon rings and tricyclic hydrocarbon rings such as homobredan, adamantane, tricyclo [5.2.1.0 ^2,6 ] decane, tricyclo [4.3.1.1 ^2,5 ] undecane ring, tetracyclo [ 4.4.0.1 ^2,5 . 1 ^7,10 ] dodecane, and tetracyclic hydrocarbon rings such as perhydro-1,4-methano-5,8-methanonaphthalene ring. The bridged cyclic hydrocarbon ring includes a condensed cyclic hydrocarbon ring such as perhydronaphthalene (decalin), perhydroanthracene, perhydrophenanthrene, perhydroacenaphthene, perhydrofluorene, perhydroindene, perhydroindene. A condensed ring in which a plurality of 5- to 8-membered cycloalkane rings such as a phenalene ring are condensed is also included.

Preferred examples of the bridged cyclic hydrocarbon ring include a norbornyl group, an adamantyl group, a bicyclooctanyl group, a tricyclo [5,2,1,0 ^2,6 ] decanyl group, and the like. More preferable examples of the bridged cyclic hydrocarbon ring include a norbornyl group and an adamantyl group.

  These alicyclic hydrocarbon groups may have a substituent, and preferred substituents include a halogen atom, an alkyl group, a hydroxyl group protected with a protecting group, an amino group protected with a protecting group, and the like. It is done. Preferred halogen atoms include bromine, chlorine and fluorine atoms, and preferred alkyl groups include methyl, ethyl, butyl and t-butyl groups. The above alkyl group may further have a substituent, and the substituent which may further have a halogen atom, an alkyl group, a hydroxyl group protected with a protecting group, an amino protected with a protecting group The group can be mentioned.

  Examples of the protecting group include an alkyl group, a cycloalkyl group, an aralkyl group, a substituted methyl group, a substituted ethyl group, an alkoxycarbonyl group, and an aralkyloxycarbonyl group. Preferred alkyl groups include alkyl groups having 1 to 4 carbon atoms, preferred substituted methyl groups include methoxymethyl, methoxythiomethyl, benzyloxymethyl, t-butoxymethyl, 2-methoxyethoxymethyl groups, and preferred substituted ethyl groups. 1-ethoxyethyl, 1-methyl-1-methoxyethyl, preferred acyl groups include formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, pivaloyl groups, etc., aliphatic acyl groups having 1 to 6 carbon atoms, alkoxycarbonyl Examples of the group include an alkoxycarbonyl group having 1 to 4 carbon atoms.

The content of the repeating unit represented by the general formula (III) having neither a hydroxyl group nor a cyano group is preferably from 0 to 40 mol%, more preferably based on all repeating units in the resin (A). 0 to 20 mol%.
Specific examples of the repeating unit represented by the general formula (III) are shown below, but the present invention is not limited thereto. In the formula, Ra represents H, CH ₃ , or CF ₃ .

  In addition to the above repeating units, the alicyclic hydrocarbon-based acid-decomposable resin includes dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general required properties of resist, resolving power, heat resistance, Various repeating units can be used for the purpose of adjusting sensitivity and the like.

  Examples of such a repeating unit include, but are not limited to, repeating units corresponding to the following monomers.

Thereby, performance required for the alicyclic hydrocarbon-based acid-decomposable resin, in particular,
(1) Solubility in coating solvent,
(2) Film formability (glass transition temperature),
(3) Solubility in positive developer and negative developer,
(4) Membrane slip (hydrophobic, alkali-soluble group selection),
(5) Adhesion of unexposed part to substrate,
(6) Dry etching resistance,
Etc. can be finely adjusted.

  As such a monomer, for example, a compound having one addition polymerizable unsaturated bond selected from acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, etc. Etc.

  In addition, any addition-polymerizable unsaturated compound that can be copolymerized with monomers corresponding to the above various repeating structural units may be copolymerized.

  In alicyclic hydrocarbon-based acid-decomposable resins, the molar ratio of each repeating structural unit is the resist dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolution that is the general required performance of resists. In order to adjust heat resistance, sensitivity, etc., it is set appropriately.

Preferred embodiments of the alicyclic hydrocarbon-based acid-decomposable resin include the following.
(1) What has a repeating unit which has a partial structure containing the alicyclic hydrocarbon represented by the said general formula (pI)-(pV) (side chain type).
Preferably, those having a (meth) acrylate repeating unit having a structure of (pI) to (pV).
(2) One having a repeating unit represented by the general formula (II-AB) (main chain type).
However, in (2), for example, the following can be further mentioned.
(3) What has a repeating unit represented by general formula (II-AB), a maleic anhydride derivative type repeating unit, and a (meth) acrylate type repeating unit (hybrid type).

In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having an acid-decomposable group is preferably 10 to 60 mol%, more preferably 20 to 50 mol%, still more preferably 25 in all repeating structural units. -40 mol%.
In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having a partial structure containing the alicyclic hydrocarbon represented by the general formulas (pI) to (pV) is 20 to 70 in all the repeating structural units. The mol% is preferable, more preferably 20 to 50 mol%, still more preferably 25 to 40 mol%.
In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit represented by the general formula (II-AB) is preferably 10 to 60 mol%, more preferably 15 to 55 mol% in all repeating structural units. More preferably, it is 20-50 mol%.
In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having a group having a lactone structure is preferably from 10 to 70 mol%, more preferably from 20 to 60 mol%, still more preferably from all repeating structural units. It is 25-40 mol%.
In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having an organic group having a polar group is preferably 1 to 40 mol%, more preferably 5 to 30 mol%, still more preferably in all repeating structural units. Is 5 to 20 mol%.

  In addition, the content of the repeating structural unit based on the monomer of the further copolymer component in the resin can also be appropriately set according to the performance of the desired resist. ) To (pV) 99 mol% with respect to the total number of moles of the repeating structural unit having a partial structure containing an alicyclic hydrocarbon and the repeating unit represented by the above general formula (II-AB) The following is preferable, More preferably, it is 90 mol% or less, More preferably, it is 80 mol% or less.

  When the negative developing resist composition of the present invention is for ArF exposure, the resin preferably has no aromatic group from the viewpoint of transparency to ArF light.

  The alicyclic hydrocarbon-based acid-decomposable resin is preferably one in which all of the repeating units are composed of (meth) acrylate-based repeating units. In this case, all of the repeating units may be methacrylate repeating units, all of the repeating units may be acrylate repeating units, and all of the repeating units may be any mixture of methacrylate repeating units / acrylate repeating units, It is preferable that the acrylate repeating unit is 50 mol% or less of the entire repeating unit.

  The alicyclic hydrocarbon-based acid-decomposable resin has at least a (meth) acrylate-based repeating unit having a group having a lactone structure, an organic group substituted with at least one of a hydroxyl group and a cyano group. It is preferable that it is a copolymer which has a unit and three types of repeating units of the (meth) acrylate type repeating unit which has an acid-decomposable group.

  Preferably, 20 to 50 mol% of repeating units having a partial structure containing an alicyclic hydrocarbon represented by general formulas (pI) to (pV), 20 to 50 mol% of repeating units having a group having a lactone structure, and polarity It is a ternary copolymer containing 5 to 30% of repeating units having an alicyclic hydrocarbon structure substituted with a group, or a quaternary copolymer containing 0 to 20% of other repeating units.

  Particularly preferable resins include 20 to 50 mol% of repeating units having an acid-decomposable group represented by the following general formulas (ARA-1) to (ARA-7), and the following general formulas (ARL-1) to (ARL- 7) The alicyclic hydrocarbon structure substituted with 20 to 50 mol% of repeating units having a group having a lactone structure represented by formula (ARH-1) to (ARH-3) shown below. A ternary copolymer containing 5 to 30 mol% of repeating units, or a carboxyl group, or a repeating unit having a structure represented by formula (F1), or an alicyclic hydrocarbon structure and acid-decomposable Is a quaternary copolymer containing 5 to 20 mol% of repeating units.

(In the formula, Rxy ₁ represents a hydrogen atom or a methyl group, Rxa ₁ and Rxb ₁ each independently represent a methyl group or an ethyl group, and Rxc ₁ represents a hydrogen atom or a methyl group.)

(In the formula, Rxy ₁ represents a hydrogen atom or a methyl group, Rxd ₁ represents a hydrogen atom or a methyl group, and Rxe ₁ represents a trifluoromethyl group, a hydroxyl group, or a cyano group.)

(In the formula, Rxy ₁ represents a hydrogen atom or a methyl group.)

  The alicyclic hydrocarbon-based acid-decomposable resin can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and heating is performed, and a solution of the monomer species and the initiator is dropped into the heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane and diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate, amide solvents such as dimethylformamide and dimethylacetamide, Furthermore, the solvent which melt | dissolves the composition of this invention like the below-mentioned propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone is mentioned. More preferably, the polymerization is performed using the same solvent as that used in the resist composition of the present invention. Thereby, generation | occurrence | production of the particle at the time of a preservation | save can be suppressed.

The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As a polymerization initiator, a commercially available radical initiator (azo initiator, peroxide, etc.) is used to initiate the polymerization. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is preferable. Preferred examples of the initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. If desired, an initiator is added or added in portions, and after completion of the reaction, it is put into a solvent and a desired polymer is recovered by a method such as powder or solid recovery. The concentration of solutes such as monomers and polymerization initiators in the reaction solution is 5 to 50% by mass, preferably 10 to 30% by mass. The reaction temperature is usually from 10 ° C to 150 ° C, preferably from 30 ° C to 120 ° C, more preferably from 60 ° C to 100 ° C.
For purification, the same method as that for the resin (D) described later can be used, and a liquid-liquid extraction method that removes residual monomers and oligomer components by combining water washing and an appropriate solvent, only those having a specific molecular weight or less. A purification method in a solution state such as ultrafiltration to extract and remove the residual monomer by coagulating the resin in the poor solvent by dropping the resin solution into the poor solvent, A usual method such as a purification method in a solid state, such as washing the filtered resin slurry with a poor solvent, can be applied.

The weight average molecular weight of the resin (A) is preferably 1,000 to 200,000, more preferably 1,000 to 20,000, and particularly preferably 1,000 to 15, as a polystyrene-converted value by the GPC method. 000. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, and developability is deteriorated, and viscosity is increased, resulting in deterioration of film forming property. Can be prevented.
The degree of dispersion (molecular weight distribution) is usually 1 to 5, preferably 1 to 3, more preferably 1.2 to 3.0, particularly preferably 1.2 to 2.0. . The smaller the degree of dispersion, the better the resolution and the resist shape, the smoother the side wall of the resist pattern, and the better the roughness.

In the resist composition of the present invention, the blending amount of all the resins according to the present invention in the entire composition is preferably 50 to 99.9% by mass, more preferably 60 to 99.0% by mass in the total solid content. is there.
In the present invention, the resins may be used alone or in combination.

When the composition of the present invention is for ArF exposure, the resin (A) used in the composition of the present invention has substantially no aromatic group from the viewpoint of transparency to ArF light (specifically, The ratio of the repeating unit having an aromatic group in the resin is preferably 5 mol% or less, more preferably 3 mol% or less, ideally 0 mol%, that is, no aromatic group). The resin (A) preferably has a monocyclic or polycyclic alicyclic hydrocarbon structure.
It is preferable that resin (A) does not have a fluorine atom and a silicon atom from a compatible viewpoint with resin (D).

(B) A photoacid generator that generates an acid represented by the general formula (I) upon irradiation with actinic rays or radiation. The resist composition of the present invention is represented by the general formula (I) upon irradiation with actinic rays or radiation. The compound which generate | occur | produces the acid represented (it is also called a "photo-acid generator" or "compound (B)").
When the resist composition of the present invention contains such a photoacid generator, an unintended phenomenon in which the acid generated from the photoacid generator in the exposed area diffuses to the unexposed area is suppressed. be able to. Although the detailed mechanism of action is unknown, in the following general formula (I), it is particularly excellent with respect to LWR, EL, and DOF that L is a group defined as follows and A is a group having a cyclic structure. It is thought that it greatly contributes to establishing the characteristics.

Where
Xf each independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom.
R ₁ and R ₂ each independently represents a hydrogen atom, a fluorine atom, an alkyl group, or a group selected from an alkyl group substituted with at least one fluorine atom, and R ₁ and R ₂ in the case where a plurality of R ₁ and R _{2 are present.} May be the same or different. However, at least one of R ₁ and R ₂ represents a hydrogen atom or an alkyl group.
L represents a divalent linking group, and when there are a plurality of L, L may be the same or different. (Note that z represents the number of repetitions of L.)
A represents a group having a cyclic structure.
x represents an integer of 1 to 20, y represents an integer of 0 to 10, and z represents an integer of 0 to 10.

General formula (I) will be described in more detail.
The alkyl group in the alkyl group substituted with the fluorine atom of Xf preferably has 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms. The alkyl group substituted with a fluorine atom of Xf is preferably a perfluoroalkyl group.
Xf is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms. Specific examples of Xf include fluorine atom, CF ₃ , C ₂ F ₅ , C ₃ F ₇ , C ₄ F ₉ , C ₅ F ₁₁ , C ₆ F ₁₃ , C ₇ F ₁₅ , C ₈ F ₁₇ , CH _{2 CF 3, CH 2 CH 2 CF} 3, CH 2 C 2 F 5, CH 2 CH 2 C 2 F 5, CH 2 C 3 F 7, CH 2 CH 2 C 3 F 7, CH 2 C 4 F 9, CH ₂ CH ₂ C ₄ F ₉ is mentioned, among which a fluorine atom and CF ₃ are preferable. In particular, it is preferable that both Xf are fluorine atoms.

The alkyl group in R ₁ and R _{2 and} the alkyl group substituted with at least one fluorine atom are preferably those having 1 to 4 carbon atoms. More preferably, it is a C1-C4 perfluoroalkyl group. Specific examples of R ₁ and R ₂ include CF ₃ , C ₂ F ₅ , C ₃ F ₇ , C ₄ F ₉ , C ₅ F ₁₁ , C ₆ F ₁₃ , C ₇ F ₁₅ , C ₈ F ₁₇ , CH _{2 CF 3, CH 2 CH 2} CF 3, CH 2 C 2 F 5, CH 2 CH 2 C 2 F 5, CH 2 C 3 F 7, CH 2 CH 2 C 3 F 7, CH 2 C 4 F 9, CH ₂ CH ₂ C ₄ F ₉ may be mentioned, among which CF ₃ is preferable.

y is preferably 0 to 4, and more preferably 0. x is preferably 1 to 8, more preferably 1 to 4, and particularly preferably 1. z is preferably 0 to 8, particularly preferably 0 to 4.
The divalent linking group for L is —COO—, —OCO—, —CO—, —O—, —S—, —SO—, an alkylene group, a cycloalkylene group, or an alkenylene group, and among these, —COO -, -OCO-, -CO-, and -O- are preferable, and -COO- and -OCO- are more preferable.

  The group having a cyclic structure of A is not particularly limited as long as it has a cyclic structure, but a cyclic group (a group formed by removing one hydrogen atom connected to any atom constituting the cyclic structure, That is, the ring structure itself is preferable. Examples of the cyclic structure include an alicyclic group, an aryl group, and a heterocyclic group (including not only those having an aromatic attribute but also those having no aromatic attribute, including, for example, a tetrahydropyran ring and a lactone ring structure). It is done.

  The alicyclic group may be monocyclic or polycyclic, and may be a monocyclic cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, or a cyclooctyl group, a norbornyl group, a tricyclodecanyl group, a tetracyclodecanyl group, or a tetracyclododecane group. A polycyclic cycloalkyl group such as a nyl group and an adamantyl group is preferred. Among them, an alicyclic group having a bulky structure having 7 or more carbon atoms such as a norbornyl group, a tricyclodecanyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group is used in the PEB (post-exposure heating) step. The diffusibility in the film can be suppressed, which is preferable from the viewpoint of improving MEEF.

  Examples of the aryl group include a benzene ring, a naphthalene ring, a phenanthrene ring, and an anthracene ring. Of these, naphthalene having low absorbance is preferred from the viewpoint of light absorbance at 193 nm.

  Examples of the heterocyclic group include a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, a dibenzothiophene ring, and a pyridine ring. Of these, a furan ring, a thiophene ring, and a pyridine ring are preferable.

  Examples of the cyclic structure include lactone structures, and specific examples include lactone structures represented by the general formulas (LC1-1) to (LC1-17).

  The group having the cyclic structure may have a substituent, and the substituent may be a halogen atom or an alkyl group (which may be linear, branched or cyclic, and has 1 to 12 carbon atoms. Preferred), a cycloalkyl group (which may be monocyclic, polycyclic or spirocyclic, preferably having 3 to 20 carbon atoms), an aryl group (preferably having 6 to 14 carbon atoms), a hydroxy group, a cyano group, Examples include an alkoxy group, an ester group, an amide group, a urethane group, a ureido group, a thioether group, a sulfonamide group, a sulfonic acid ester group, and a group formed by combining two or more selected from these atoms and groups. It is done. The carbon constituting the cyclic structure (carbon contributing to ring formation) may be carbonyl carbon.

Examples of preferred embodiments of general formula (I) include the following general formulas (Ia) and (Ib). In the formula, Xf, R ₁ , R ₂ , L, A, y, and z have the same meanings as those in general formula (I).

Among the compounds that generate an acid represented by the general formula (I) upon irradiation with actinic rays or radiation, preferred compounds include compounds having an ionic structure such as sulfonium salts and iodonium salts, oxime esters, imide esters and the like. The thing which has an ionic compound structure is mentioned. Examples of the compound having an ionic structure include compounds represented by the following general formulas (ZI) and (ZII).

In the general formula (ZI),
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1 to 30, preferably 1 to 20.
Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. Examples of the group formed by combining two of R _{201 to} R ₂₀₃ include an alkylene group (eg, butylene group, pentylene group).
Z ⁻ represents the anion structure of the acid represented by the general formula (I).

In addition, the compound which has two or more structures represented by general formula (ZI) may be sufficient. For example, at least one of R _{201 to} R ₂₀₃ of the compound represented by the general formula (ZI) is a single bond or at least one of R _{201 to} R ₂₀₃ of another compound represented by the general formula (ZI) It may be a compound having a structure bonded through a linking group.

  More preferred (ZI) components include compounds (ZI-1), (ZI-2), (ZI-3) and (ZI-4) described below.

The compound (ZI-1) is an arylsulfonium compound in which at least one of R _{201 to} R _{203 in} the general formula (ZI) is an aryl group, that is, a compound having arylsulfonium as a cation.

In the arylsulfonium compound, all of R _{201 to} R ₂₀₃ may be an aryl group, or a part of R _{201 to} R ₂₀₃ may be an aryl group, and the rest may be an alkyl group or a cycloalkyl group.

  Examples of the arylsulfonium compound include triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, and aryldicycloalkylsulfonium compounds.

  The aryl group of the arylsulfonium compound is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom or the like. Examples of the heterocyclic structure include a pyrrole residue, a furan residue, a thiophene residue, an indole residue, a benzofuran residue, and a benzothiophene residue. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.

  The alkyl group or cycloalkyl group that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms and a cycloalkyl group having 3 to 15 carbon atoms, such as a methyl group, Examples thereof include an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

The aryl group, alkyl group and cycloalkyl group of R _{201 to} R ₂₀₃ are an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms). , An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group may be substituted. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, more preferably carbon. These are an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms. The substituent may be substituted with any one of three R _{201 to} R ₂₀₃ , or may be substituted with all three. When R _{201 to} R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

Next, the compound (ZI-2) will be described.
Compound (ZI-2) is a compound in which R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group having no aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.

The organic group not containing an aromatic ring as R _{201 to} R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.
R _{201 to} R ₂₀₃ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, 2-oxocycloalkyl group, alkoxy group. A carbonylmethyl group, particularly preferably a linear or branched 2-oxoalkyl group.

As the alkyl group and cycloalkyl group of R _{201 to} R ₂₀₃ , a linear or branched alkyl group having 1 to 10 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group), carbon Examples thereof include cycloalkyl groups of several 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group). More preferred examples of the alkyl group include a 2-oxoalkyl group and an alkoxycarbonylmethyl group. More preferred examples of the cycloalkyl group include a 2-oxocycloalkyl group.

The 2-oxoalkyl group may be either linear or branched, and a group having> C = O at the 2-position of the above alkyl group is preferable.
The 2-oxocycloalkyl group is preferably a group having> C═O at the 2-position of the cycloalkyl group.

  The alkoxy group in the alkoxycarbonylmethyl group is preferably an alkoxy group having 1 to 5 carbon atoms (methoxy group, ethoxy group, propoxy group, butoxy group, pentoxy group).

R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (eg, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

  The compound (ZI-3) is a compound represented by the following general formula (ZI-3), and is a compound having a phenacylsulfonium salt structure.

In general formula (ZI-3),
R _{1c to} R _5c are each independently a hydrogen atom, a linear or branched alkyl group (preferably having 1 to 12 carbon atoms), a cycloalkyl group (preferably having 3 to 8 carbon atoms), a linear or branched alkoxy group. A group (C1-C12 is preferable in the case of a straight chain, C3-C8 is preferable in the case of a branch), or represents a halogen atom.

R _6c and R _7c each independently represent a hydrogen atom, a linear or branched alkyl group (preferably having 1 to 12 carbon atoms) or a cycloalkyl group (preferably having 3 to 8 carbon atoms).
R _x and R _y each independently represents a linear or branched alkyl group (preferably having 1 to 12 carbon atoms), a cycloalkyl group (preferably having 3 to 8 carbon atoms), an allyl group or a vinyl group.

Any two or more of R _{1c to} R _5c , R _5c and R _6c , R _6c and R _7c , and R _x and R _y may be bonded to each other to form a ring structure, , An oxygen atom, a sulfur atom, an ester bond, and an amide bond may be included.
Examples of the ring structure include an aromatic or non-aromatic hydrocarbon ring, an aromatic or non-aromatic heterocycle, or a polycyclic fused ring formed by combining two or more of these rings. Examples of the ring structure include 3- to 10-membered rings, preferably 4- to 8-membered rings, and more preferably 5- or 6-membered rings.
Zc ^- is, Z ^- represents an anion structure of the acid represented by the same general formula (I) and.

  Specific examples of suitable cations of the compound (ZI-3) include those described in paragraphs 0046 and 0047 of JP-A-2004-233661, paragraphs 0040 to 0046 of JP-A-2003-35948, and US2003 / 0224288A1. Compounds exemplified as (I-1) to (I-70), formulas (IA-1) to (IA-54), formulas (IB-1) to (IB-24) in US2003 / 0077540A1 And the compounds exemplified as the above.

  The compound (ZI-4) is a compound represented by the following general formula (ZI-4).

In general formula (ZI-4),
R ₁₃ represents a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, or an alkoxycarbonyl group.
When a plurality of R ₁₄ are present, each independently represents a hydroxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkylsulfonyl group, or a cycloalkylsulfonyl group.
R ₁₅ each independently represents an alkyl group or a cycloalkyl group. Two R ₁₅ may be bonded to each other to form a ring.
l represents an integer of 0-2.
r represents an integer of 0 to 10.
Z ⁻ represents the anion structure of the acid represented by the general formula (I).

In formula _(ZI-4), the alkyl group of R _{13, R 14} and _{R 15,} may be linear or branched, preferably has 1 to 10 carbon atoms, a methyl group, an ethyl radical, n -Propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n -An octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group etc. can be mentioned. Of these alkyl groups, a methyl group, an ethyl group, an n-butyl group, a t-butyl group, and the like are preferable.

Examples of the cycloalkyl group of R ₁₃ , R ₁₄ and R ₁₅ include monocyclic or polycyclic cycloalkyl groups (preferably cycloalkyl groups having 3 to 20 carbon atoms), and cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl , Cycloheptyl, cyclooctyl, cyclododecanyl, cyclopentenyl, cyclohexenyl, cyclooctadienyl, and the like, with cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl being particularly preferred.

The alkoxy group of R ₁₃ and R ₁₄ is linear or branched and preferably has 1 to 10 carbon atoms, such as methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n -Butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group, n-pentyloxy group, neopentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, 2-ethylhexyloxy group, n-nonyloxy group, n-decyloxy group and the like can be mentioned. Of these alkoxy groups, a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, and the like are preferable.

The alkoxycarbonyl group for R ₁₃ is linear or branched and preferably has 2 to 11 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, or an i-propoxycarbonyl group. N-butoxycarbonyl group, 2-methylpropoxycarbonyl group, 1-methylpropoxycarbonyl group, t-butoxycarbonyl group, n-pentyloxycarbonyl group, neopentyloxycarbonyl group, n-hexyloxycarbonyl group, n-heptyl Examples thereof include an oxycarbonyl group, an n-octyloxycarbonyl group, a 2-ethylhexyloxycarbonyl group, an n-nonyloxycarbonyl group, and an n-decyloxycarbonyl group. Of these alkoxycarbonyl groups, a methoxycarbonyl group, an ethoxycarbonyl group, an n-butoxycarbonyl group, and the like are preferable.

The alkylsulfonyl group and cycloalkylsulfonyl group of R ₁₄ are linear, branched, or cyclic, and preferably those having 1 to 10 carbon atoms, such as methanesulfonyl group, ethanesulfonyl group, n-propanesulfonyl. Group, n-butanesulfonyl group, tert-butanesulfonyl group, n-pentanesulfonyl group, neopentanesulfonyl group, n-hexanesulfonyl group, n-heptanesulfonyl group, n-octanesulfonyl group, 2-ethylhexanesulfonyl group n -Nonanesulfonyl group, n-decanesulfonyl group, cyclopentanesulfonyl group, cyclohexanesulfonyl group, etc. can be mentioned. Of these alkylsulfonyl groups, a methanesulfonyl group, an ethanesulfonyl group, an n-propanesulfonyl group, an n-butanesulfonyl group, a cyclopentanesulfonyl group, a cyclohexanesulfonyl group, and the like are preferable.

l is preferably 0 or 1, and more preferably 1. As r, 0-2 are preferable.
Examples of the substituent that each group of R ₁₃ , R ₁₄ , and R ₁₅ may have include a halogen atom (for example, a fluorine atom), a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxy group, and an alkoxy group. Examples thereof include an alkyl group, an alkoxycarbonyl group, and an alkoxycarbonyloxy group.

  Examples of the alkoxy group include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group, cyclopentyloxy group, Examples thereof include a linear, branched or cyclic alkoxy group having 1 to 20 carbon atoms such as a cyclohexyloxy group.

  Examples of the alkoxyalkyl group include straight chain having 2 to 21 carbon atoms such as methoxymethyl group, ethoxymethyl group, 1-methoxyethyl group, 2-methoxyethyl group, 1-ethoxyethyl group, and 2-ethoxyethyl group. Examples thereof include a chain, branched or cyclic alkoxyalkyl group.

  Examples of the alkoxycarbonyl group include methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, i-propoxycarbonyl group, n-butoxycarbonyl group, 2-methylpropoxycarbonyl group, 1-methylpropoxycarbonyl group, t Examples thereof include linear, branched or cyclic alkoxycarbonyl groups having 2 to 21 carbon atoms such as butoxycarbonyl group, cyclopentyloxycarbonyl group, cyclohexyloxycarbonyl and the like.

  Examples of the alkoxycarbonyloxy group include a methoxycarbonyloxy group, an ethoxycarbonyloxy group, an n-propoxycarbonyloxy group, an i-propoxycarbonyloxy group, an n-butoxycarbonyloxy group, a t-butoxycarbonyloxy group, and a cyclopentyloxy group. Examples thereof include linear, branched or cyclic alkoxycarbonyloxy groups having 2 to 21 carbon atoms such as carbonyl group and cyclohexyloxycarbonyl.

When two R ₁₅ are bonded to each other to form a ring structure, the group formed by bonding two R ₁₅ to each other is a 5- or 6-membered ring together with the sulfur atom in the general formula (ZI-4). Particularly preferred is a divalent group that forms a 5-membered ring (that is, a tetrahydrothiophene ring). In addition, examples of the substituent for the divalent group include a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxy group, an alkoxyalkyl group, an alkoxycarbonyl group, and an alkoxycarbonyloxy group. As R ₁₅ in the general formula (ZI-4), a methyl group, an ethyl group, a phenyl group, a 4-methoxyphenyl group, a 1-naphthyl group, and two R ₁₅ are bonded to each other to form a tetrahydrothiophene ring structure together with a sulfur atom. A divalent group or the like that forms is preferable.

The alkyl group, cycloalkyl group, alkoxy group, or alkoxycarbonyl group of R _13, the alkyl group, cycloalkyl group, alkoxy group, alkylsulfonyl group, and cycloalkylsulfonyl group of R ₁₄ may be substituted as described above. The substituent is preferably a hydroxyl group, an alkoxy group, an alkoxycarbonyl group, or a halogen atom (particularly a fluorine atom).
Below, the preferable specific example of the cation in the compound represented by general formula (ZI-4) is shown.

  Furthermore, the specific example of the cation in the compound represented by general formula (ZI) is shown.

Next, general formula (ZII) will be described.
In General Formula (ZII), R ₂₀₄ and R ₂₀₅ each independently represents an aryl group, an alkyl group, or a cycloalkyl group.
The aryl group, alkyl group, and cycloalkyl group of R ₂₀₄ and R ₂₀₅ are the same as the groups described as the aryl group, alkyl group, and cycloalkyl group of R _{201 to} R ₂₀₃ in the aforementioned compound (ZI-1). is there.

The aryl group, alkyl group, and cycloalkyl group of R _{204 to} R ₂₀₅ may have a substituent. As this substituent, the same substituents as those which the aryl group, alkyl group, and cycloalkyl group of R _{201 to} R ₂₀₃ in the above-described compound (ZI-1) may have may be mentioned.
Z ⁻ represents the anion structure of the acid represented by the general formula (I).
Specific examples of the cation in the compound represented by the general formula (ZII) are shown.

  Examples of the acid generator further include compounds represented by the following general formulas (ZV) and (ZVI).

In general formulas (ZV) and (ZVI),
R ₂₀₉ and R ₂₁₀ each independently represents an alkyl group, a cycloalkyl group or an aryl group. The aryl group, alkyl group, and cycloalkyl group of R ₂₀₉ and R ₂₁₀ are the same as the groups described as the aryl group, alkyl group, and cycloalkyl group of R _{201 to} R ₂₀₃ in the aforementioned compound (ZI-1). is there. The aryl group, alkyl group, and cycloalkyl group of R ₂₀₉ and R ₂₁₀ may have a substituent. As this substituent, the same substituents as those which the aryl group, alkyl group, and cycloalkyl group of R _{201 to} R ₂₀₃ in the above-described compound (ZI-1) may have may be mentioned.

A ′ represents an alkylene group, an alkenylene group or an arylene group.
The alkylene group as A ′ may have a substituent, and preferably has 1 to 8 carbon atoms, for example, methylene group, ethylene group, propylene group, butylene group, hexylene group, octylene group and the like. it can.
The alkenylene group as A ′ may have a substituent, and preferably has 2 to 6 carbon atoms, for example, ethenylene group, propenylene group, butenylene group and the like.
The arylene group as A ′ may have a substituent, and preferably has 6 to 15 carbon atoms, such as a phenylene group, a tolylene group, and a naphthylene group.

  Examples of the substituent that A ′ may have include those having active hydrogen such as a cycloalkyl group, an aryl group, an amino group, an amide group, a ureido group, a urethane group, a hydroxyl group, and a carboxyl group, and a halogen atom. (Fluorine atom, chlorine atom, bromine atom, iodine atom), alkoxy group (eg methoxy group, ethoxy group, propoxy group, butoxy group, etc.), thioether group, acyl group (acetyl group, propanoyl group, benzoyl group, etc.), acyloxy Groups (acetoxy group, propanoyloxy group, benzoyloxy group, etc.), alkoxycarbonyl groups (methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, etc.), cyano group, nitro group and the like. Further, the arylene group may further include an alkyl group (methyl group, ethyl group, propyl group, butyl group, etc.).

  Rz represents a structure in which H of the acid represented by the general formula (I) is dissociated, and is represented by the following general formula (I-s).

In the formula, R ₁ , R ₂ , L, A, Xf, x, y, and z are the same as those in the general formula (I). * Represents a bond with a compound residue represented by the general formulas (ZV) and (ZVI).
Specific examples of the compound residues represented by the general formulas (ZV) and (ZVI) are shown below. * In a specific example represents a coupling | bond part with * of the said general formula (I-s).

  The acid represented by the general formula (I) generated by the photoacid generator is preferably an acid represented by the following general formula (II) or (III).

  Specific examples and preferred examples of A in the general formulas (II) and (III) are the same as those described for A in the general formula (I).

Therefore, in the compound represented by the above (ZI), (ZII), (ZV) or (ZVI), Z ⁻ and Rz correspond to the acid represented by the general formula (II) or (III), respectively. It is preferable to show a structure in which the anion and H of the acid represented by the general formula (II) or (III) are dissociated.

It is preferable that A in the acids represented by the general formulas (I) to (III) does not contain a fluorine atom, and as a result, improvement in distribution uniformity of the photoacid generator in the resist film can be expected.
Among these, as the photoacid generator, a photoacid generator represented by the general formula (II) and which generates an acid having two fluorine atoms (hereinafter, this photoacid generator is referred to as a photoacid generator). (It is also referred to as agent (II ′)). That is, in the acid represented by the general formula (II) from which the photoacid generator (II ′) is generated, A in the general formula (II) does not have a fluorine atom.

  The acid generated by the photoacid generator (II ′) has two fluorine atoms, so that the acidity of the acid is not too high and the polarity of the unexposed portion of the resist film is not intended. Therefore, when negative development is performed, excellent results can be obtained more reliably with respect to all of line width variation (LWR), exposure latitude (EL), and focus margin (DOF) (especially LWR). It is possible to stably form a fine pattern.

  In the general formulas (I), (II) and (III), as the group having a cyclic structure represented by A (including A in the general formula (II) in the photoacid generator (II ′)), Preferable examples include groups represented by general formula (IV).

In general formula (IV), Rc represents a monocyclic or polycyclic organic group having 3 to 30 carbon atoms which may contain a cyclic ether, a cyclic thioether, a cyclic ketone, a cyclic carbonate, a lactone, or a lactam structure.
Y is a hydroxyl group, a halogen atom, a cyano group, a carboxyl group, a hydrocarbon group having 1 to 10 carbon atoms, a hydroxyalkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an acyl having 1 to 10 carbon atoms. Group, an alkoxycarbonyl group having 2 to 10 carbon atoms, an acyloxy group having 2 to 10 carbon atoms, an alkoxyalkyl group having 2 to 10 carbon atoms, and a halogenated alkyl group having 1 to 8 carbon atoms.
m is an integer of 0 to 6, and when a plurality of Y are present, they may be the same as or different from each other. n is an integer of 0-10.

  The total number of carbon atoms constituting the group having a cyclic structure represented by the general formula (IV) is preferably 40 or less. In general formula (IV), n is an integer of 0 to 3, and Rc is preferably a monocyclic or polycyclic organic group having 7 to 16 carbon atoms. Specific examples and preferred examples of Rc are the same as the specific examples and preferred examples of the cyclic structure in A described in the general formula (I).

In the general formulas (I), (II), and (III), the cyclic structure in A (including A in the general formula (II) in the photoacid generator (II ′) has 5 or more carbon atoms. It is preferable. Here, the cyclic structure having 5 or more carbon atoms means that there are 5 or more carbon atoms contributing to ring formation.
Thereby, since the diffusion of the acid generated in the exposed portion to the non-exposed portion can be more reliably suppressed, particularly excellent results can be obtained with respect to LWR.
More preferably, the cyclic structure in A has 5 to 20 carbon atoms, and more preferably 6 to 10 carbon atoms.
By setting the number of carbon atoms of the cyclic structure in A to 20 or less, the acid diffusion length can be sufficiently obtained in the exposed portion, so that a desired pattern can be reliably formed.

  The molecular weight of the compound (B) is generally 300 to 1000, preferably 400 to 800, and more preferably 500 to 700.

  Specific examples of the acid represented by the general formula (I) are shown below.

  Among the specific examples, more preferable acids are shown below.

  Specific examples of the compound capable of generating an acid represented by the general formula (I) include the cation structure having the specific structure shown in the general formulas (ZI) and (ZII) and the general formula (I A combination of an anion structure, which is a specific structure of an acid represented by (II), and a specific structure of (ZV), (ZVI) and an acid H, which is a specific structure of an acid represented by formula (I), Combination with dissociated formula (I-s).

  Specific examples of the compound (B) include the following compounds, but are not limited thereto.

Compound (B) can be synthesized by a known method, for example, according to the method described in JP-A No. 2007-161707.
A compound (B) can be used 1 type or in combination of 2 or more types.
The content of the compound (B) in the resist composition is preferably 0.1 to 20% by mass, more preferably 0.1 to 15% by mass, and still more preferably, based on the total solid content of the resist composition. It is 0.5-15 mass%, Most preferably, it is 0.5-10 mass%, Most preferably, it is 1-7 mass%.

  The compound (B) may be used in combination with an acid generator other than the compound (B).

  Examples of the acid generator other than compound (B) that can be used in combination with compound (B) include the acid generators described in [0150] of US Patent Application Publication No. 2008/0248425.

  Examples of the acid generator other than the compound (B) that can be used in combination include a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization, a photodecolorant for dyes, a photochromic agent, or Known compounds that generate an acid upon irradiation with actinic rays or radiation used in microresists and the like and mixtures thereof can be appropriately selected and used.

  In addition, other diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates can be used in combination. A compound in which a group to be generated or a compound is introduced into a main chain or a side chain of a polymer, for example, US Pat. No. 3,849,137, German Patent No. 3914407, JP-A 63-26653 JP, 55-164824, JP, 62-69263, JP, 63-146038, JP, 63-163452, JP, 62-153853, JP, 63. The compounds described in JP-A-146029 and the like can be used.

Furthermore, compounds capable of generating an acid by light described in US Pat. No. 3,779,778, European Patent 126,712, etc. can also be used.
As preferred compounds among the acid generators (B ′) other than the acid generator (B) that can be used in combination with the acid generator (B) that generates an acid represented by the general formula (I), Mention may be made of compounds represented by the general formulas (ZI ′), (ZII ′), (ZIII ′).

In the above general formulas (ZI ′) and (ZII ′),
R ₂₀₁ , R ₂₀₂ , R ₂₀₃ , R ₂₀₄ , and R ₂₀₅ have the same meanings as in general formulas (ZI) and (ZII) described above.
Z ⁻ represents a non-nucleophilic anion.
Examples of the non-nucleophilic anion as Z ⁻ include a sulfonate anion, a carboxylate anion, a sulfonylimide anion, a bis (alkylsulfonyl) imide anion, and a tris (alkylsulfonyl) methide anion.

  A non-nucleophilic anion is an anion that has an extremely low ability to cause a nucleophilic reaction, and is an anion that can suppress degradation over time due to an intramolecular nucleophilic reaction. This improves the temporal stability of the resist.

Examples of the sulfonate anion include an aliphatic sulfonate anion, an aromatic sulfonate anion, and a camphor sulfonate anion.
Examples of the carboxylate anion include an aliphatic carboxylate anion, an aromatic carboxylate anion, and an aralkylcarboxylate anion.

  The aliphatic moiety in the aliphatic sulfonate anion may be an alkyl group or a cycloalkyl group, preferably an alkyl group having 1 to 30 carbon atoms and a cycloalkyl group having 3 to 30 carbon atoms such as methyl. Group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group , Tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, adamantyl group, norbornyl group, bornyl group and the like.

  The aromatic group in the aromatic sulfonate anion is preferably an aryl group having 6 to 14 carbon atoms, such as a phenyl group, a tolyl group, and a naphthyl group.

  The alkyl group, cycloalkyl group and aryl group in the aliphatic sulfonate anion and aromatic sulfonate anion may have a substituent. Examples of the substituent of the alkyl group, cycloalkyl group, and aryl group in the aliphatic sulfonate anion and aromatic sulfonate anion include, for example, a nitro group, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), carboxyl group , Hydroxyl group, amino group, cyano group, alkoxy group (preferably having 1 to 15 carbon atoms), cycloalkyl group (preferably having 3 to 15 carbon atoms), aryl group (preferably having 6 to 14 carbon atoms), alkoxycarbonyl group ( Preferably 2 to 7 carbon atoms, acyl group (preferably 2 to 12 carbon atoms), alkoxycarbonyloxy group (preferably 2 to 7 carbon atoms), alkylthio group (preferably 1 to 15 carbon atoms), alkylsulfonyl group (Preferably 1 to 15 carbon atoms), alkyliminosulfonyl group (preferably 2 to 15 carbon atoms), ant Ruoxysulfonyl group (preferably having 6 to 20 carbon atoms), alkylaryloxysulfonyl group (preferably having 7 to 20 carbon atoms), cycloalkylaryloxysulfonyl group (preferably having 10 to 20 carbon atoms), alkyloxyalkyloxy group (Preferably having 5 to 20 carbon atoms), a cycloalkylalkyloxyalkyloxy group (preferably having 8 to 20 carbon atoms), and the like. About the aryl group and ring structure which each group has, an alkyl group (preferably C1-C15) can further be mentioned as a substituent.

Examples of the aliphatic moiety in the aliphatic carboxylate anion include the same alkyl group and cycloalkyl group as in the aliphatic sulfonate anion.
Examples of the aromatic group in the aromatic carboxylate anion include the same aryl group as in the aromatic sulfonate anion.

  The aralkyl group in the aralkyl carboxylate anion is preferably an aralkyl group having 7 to 12 carbon atoms, such as a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group, and a naphthylbutyl group.

  The alkyl group, cycloalkyl group, aryl group and aralkyl group in the aliphatic carboxylate anion, aromatic carboxylate anion and aralkylcarboxylate anion may have a substituent. Examples of the substituent of the alkyl group, cycloalkyl group, aryl group and aralkyl group in the aliphatic carboxylate anion, aromatic carboxylate anion and aralkylcarboxylate anion include, for example, the same halogen atom and alkyl as in the aromatic sulfonate anion Group, cycloalkyl group, alkoxy group, alkylthio group and the like.

Examples of the sulfonylimide anion include saccharin anion.
The alkyl group in the bis (alkylsulfonyl) imide anion and tris (alkylsulfonyl) methide anion is preferably an alkyl group having 1 to 5 carbon atoms, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl. Group, sec-butyl group, pentyl group, neopentyl group and the like. Examples of substituents for these alkyl groups include halogen atoms, alkyl groups substituted with halogen atoms, alkoxy groups, alkylthio groups, alkyloxysulfonyl groups, aryloxysulfonyl groups, cycloalkylaryloxysulfonyl groups, and the like. Alkyl groups substituted with fluorine atoms are preferred.

Examples of other non-nucleophilic anions include fluorinated phosphorus, fluorinated boron, and fluorinated antimony.
Examples of the non-nucleophilic anion of Z ⁻ include an aliphatic sulfonate anion in which the α-position of the sulfonic acid is substituted with a fluorine atom, an aromatic sulfonate anion substituted with a fluorine atom or a group having a fluorine atom, and an alkyl group. A bis (alkylsulfonyl) imide anion substituted with a fluorine atom and a tris (alkylsulfonyl) methide anion wherein an alkyl group is substituted with a fluorine atom are preferred. The non-nucleophilic anion is more preferably a perfluoroaliphatic sulfonic acid anion having 4 to 8 carbon atoms, a benzenesulfonic acid anion having a fluorine atom, still more preferably a nonafluorobutanesulfonic acid anion, a perfluorooctanesulfonic acid anion, It is a pentafluorobenzenesulfonic acid anion and 3,5-bis (trifluoromethyl) benzenesulfonic acid anion.

In addition, the compound which has two or more structures represented by general formula (ZI ') may be sufficient. For example, at least one of R _{201 to} R ₂₀₃ of the compound represented by the general formula (ZI ′) is bonded to at least one of R _{201 to} R ₂₀₃ of another compound represented by the general formula (ZI ′). It may be a compound having a structure.

  More preferred (ZI ′) components include compounds (ZI-1 ′), (ZI-2 ′) and (ZI-3 ′) described below.

The compound (ZI-1 ′) is an arylsulfonium compound in which at least one of R _{201 to} R _{203 in} the general formula (ZI ′) is an aryl group, that is, a compound having arylsulfonium as a cation. _R 201 _{to R 203} in the compound (ZI-1 ') is the same as _R 201 _{to R 203} in the compound described above (ZI-1).

Next, the compound (ZI-2 ′) will be described.
Compound (ZI-2 ′) is a compound in which R _{201 to} R ₂₀₃ in formula (ZI ′) each independently represents an organic group having no aromatic ring. _R 201 _{to R 203} in the compound (ZI-2 ') is the same as _R 201 _{to R 203} in the compound described above (ZI-2).

  The compound (ZI-3 ′) is a compound represented by the following general formula (ZI-3 ′), and is a compound having a phenacylsulfonium salt structure.

In the general formula (ZI-3 ′),
R _{< 1c} > -R _{< 7c>} , R _{<x >} , R _{< y} > is synonymous with each in general formula (ZI-3) mentioned above.

Zc ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as Z ⁻ in formula (ZI ′).

In general formulas (ZII ′) and (ZIII ′),
R ₂₀₄ to R ₂₀₇ each independently represents an aryl group, an alkyl group or a cycloalkyl group.

The aryl group for R _{204 to} R ₂₀₇ is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group of R _{204 to} R ₂₀₇ may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Examples of the aryl group having a heterocyclic structure include a pyrrole residue (a group formed by losing one hydrogen atom from pyrrole) and a furan residue (a group formed by losing one hydrogen atom from furan). Groups), thiophene residues (groups formed by the loss of one hydrogen atom from thiophene), indole residues (groups formed by the loss of one hydrogen atom from indole), benzofuran residues ( A group formed by losing one hydrogen atom from benzofuran), a benzothiophene residue (a group formed by losing one hydrogen atom from benzothiophene), and the like.

The alkyl group and cycloalkyl group in R _{204 to} R ₂₀₇ are preferably a linear or branched alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group, butyl group, pentyl group), carbon Examples thereof include cycloalkyl groups of several 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group).

The aryl group, alkyl group, and cycloalkyl group of R _{204 to} R ₂₀₇ may have a substituent. Aryl group, alkyl group of R ₂₀₄ to R _207, the cycloalkyl group substituent which may be possessed by, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms ), An aryl group (for example, having 6 to 15 carbon atoms), an alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group.

Z ⁻ represents a non-nucleophilic anion, and examples thereof include the same as the non-nucleophilic anion of Z ^{− in} the general formula (ZI ′).
Examples of the acid generator further include compounds represented by the following general formulas (ZIV ′), (ZV ′), and (ZVI ′).

In general formulas (ZIV ′) to (ZVI ′),
Ar ₃ and Ar ₄ each independently represents an aryl group.
R ₂₀₈ , R ₂₀₉ and R ₂₁₀ each independently represents an alkyl group, a cycloalkyl group or an aryl group.
A represents an alkylene group, an alkenylene group or an arylene group.
Specific examples of the aryl group represented by Ar ₃ , Ar ₄ , R ₂₀₈ , R _209, and R ₂₁₀ are the same as the specific examples of the aryl group represented by R ₂₀₁ , R _202, and R ₂₀₃ in the general formula (ZI-1 ′). Can be mentioned.
Specific examples of the alkyl group and the cycloalkyl group represented by R ₂₀₈ , R _209, and R ₂₁₀ include an alkyl group and a cycloalkyl group represented by R ₂₀₁ , R _202, and R ₂₀₃ in the general formula (ZI-2 ′), respectively. The thing similar to a specific example can be mentioned.
The alkylene group of A is alkylene having 1 to 12 carbon atoms (for example, methylene group, ethylene group, propylene group, isopropylene group, butylene group, isobutylene group, etc.), and the alkenylene group of A is 2 to 2 carbon atoms. 12 alkenylene groups (for example, ethynylene group, propenylene group, butenylene group, etc.), and the arylene group of A is an arylene group having 6 to 10 carbon atoms (for example, phenylene group, tolylene group, naphthylene group, etc.) Can be mentioned.
Of the acid generators (B ′), compounds represented by the general formulas (ZI ′) to (ZIII ′) are more preferable.

The acid generator (B ′) is preferably a compound that generates an acid having one sulfonic acid group or imide group, more preferably a compound that generates monovalent perfluoroalkanesulfonic acid, or monovalent fluorine. A compound that generates an aromatic sulfonic acid substituted with an atom or a group containing a fluorine atom, or a compound that generates an imide acid substituted with a monovalent fluorine atom or a group containing a fluorine atom, and more preferably Is a sulfonium salt of a fluorinated substituted alkane sulfonic acid, a fluorinated benzene sulfonic acid, a fluorinated imide acid or a fluorinated methide acid. The acid generator that can be used is particularly preferably a fluorinated substituted alkane sulfonic acid, a fluorinated substituted benzene sulfonic acid, or a fluorinated substituted imido acid whose pKa of the generated acid is −1 or less, and the sensitivity is improved.
Among acid generators, particularly preferred examples are given below.

  The total amount of the photoacid generator (including an acid generator other than the compound (B) when the acid generator is used) is 0.1 to 0.1 on the basis of the total solid content of the resist composition. 25% by mass is preferable, 0.1 to 20% by mass is more preferable, 0.5 to 20% by mass is further preferable, 0.5 to 10% by mass is particularly preferable, and 1 to 15% by mass is particularly preferable, and particularly preferable. Is 1-7 mass%.

  When the compound (B) and an acid generator other than the compound (B) are used in combination, the acid generator is used in a molar ratio (compound (B) / other acid generator), usually 99/1 to 1 20/80, preferably 99/1 to 40/60, more preferably 99/1 to 50/50.

(C) Solvent The resist composition of the present invention preferably contains a solvent (C).
Solvents that can be used when preparing the resist composition by dissolving the above components include, for example, alkylene glycol monoalkyl ether carboxylate, alkylene glycol monoalkyl ether, alkyl lactate ester, alkyl alkoxypropionate, cyclic Examples thereof include organic solvents such as lactones (preferably having 4 to 10 carbon atoms), monoketone compounds (preferably having 4 to 10 carbon atoms) which may have a ring, alkylene carbonate, alkyl alkoxyacetate, and alkyl pyruvate.
Specific examples of these solvents can include those described in US Patent Application Publication No. 2008/0187860 [0441] to [0455].

In this invention, you may use the mixed solvent which mixed the solvent which contains a hydroxyl group in a structure, and the solvent which does not contain a hydroxyl group as an organic solvent.
As the solvent containing a hydroxyl group and the solvent not containing a hydroxyl group, the above-described exemplary compounds can be selected as appropriate, but as the solvent containing a hydroxyl group, alkylene glycol monoalkyl ether, alkyl lactate, etc. are preferable, propylene glycol monomethyl ether, More preferred is ethyl lactate. Further, as the solvent not containing a hydroxyl group, alkylene glycol monoalkyl ether acetate, alkyl alkoxypropionate, monoketone compound which may contain a ring, cyclic lactone, alkyl acetate and the like are preferable, and among these, propylene glycol monomethyl ether Acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone and butyl acetate are particularly preferred, and propylene glycol monomethyl ether acetate, ethyl ethoxypropionate and 2-heptanone are most preferred.
The mixing ratio (mass) of the solvent containing a hydroxyl group and the solvent not containing a hydroxyl group is 1/99 to 99/1, preferably 10/90 to 90/10, more preferably 20/80 to 60/40. . A mixed solvent containing 50% by mass or more of a solvent not containing a hydroxyl group is particularly preferred from the viewpoint of coating uniformity.
The solvent is preferably a mixed solvent of two or more containing propylene glycol monomethyl ether acetate.

(D) Resin having at least one of fluorine atom and silicon atom The resist composition of the present invention preferably contains a resin (D) having at least one of a fluorine atom and a silicon atom.
The fluorine atom or silicon atom in the resin (D) may be contained in the main chain of the resin or may be substituted with a side chain.

The resin (D) is preferably a resin having an alkyl group having a fluorine atom, a cycloalkyl group having a fluorine atom, or an aryl group having a fluorine atom as a partial structure having a fluorine atom.
The alkyl group having a fluorine atom (preferably having 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms) is a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom. It may have a substituent.
The cycloalkyl group having a fluorine atom is a monocyclic or polycyclic cycloalkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and may further have another substituent.
Examples of the aryl group having a fluorine atom include those in which at least one hydrogen atom of an aryl group such as a phenyl group or a naphthyl group is substituted with a fluorine atom, and the aryl group may further have another substituent.

  Specific examples of the alkyl group having a fluorine atom, the cycloalkyl group having a fluorine atom, or the aryl group having a fluorine atom are shown below, but the present invention is not limited thereto.

In general formulas (F2) to (F4),
R _{57 to} R ₆₈ each independently represents a hydrogen atom, a fluorine atom or an alkyl group. Provided that at least one of R _{57 to} R ₆₁ , at least one of R _{62 to} R ₆₄ and at least one of R _{65 to} R ₆₈ are fluorine atoms or at least one hydrogen atom is a fluorine atom. Represents an alkyl group (preferably having 1 to 4 carbon atoms) substituted with. R _{57 to} R ₆₁ and R _{65 to} R ₆₇ are preferably all fluorine atoms. R ₆₂ , R ₆₃ and R ₆₈ are preferably an alkyl group (preferably having 1 to 4 carbon atoms) in which at least one hydrogen atom is substituted with a fluorine atom, and preferably a perfluoroalkyl group having 1 to 4 carbon atoms. Further preferred. R ₆₂ and R ₆₃ may be connected to each other to form a ring.

Specific examples of the group represented by the general formula (F2) include a p-fluorophenyl group, a pentafluorophenyl group, and a 3,5-di (trifluoromethyl) phenyl group.
Specific examples of the group represented by the general formula (F3) include trifluoroethyl group, pentafluoropropyl group, pentafluoroethyl group, heptafluorobutyl group, hexafluoroisopropyl group, heptafluoroisopropyl group, hexafluoro (2 -Methyl) isopropyl group, nonafluorobutyl group, octafluoroisobutyl group, nonafluorohexyl group, nonafluoro-t-butyl group, perfluoroisopentyl group, perfluorooctyl group, perfluoro (trimethyl) hexyl group, 2,2 , 3,3-tetrafluorocyclobutyl group, perfluorocyclohexyl group and the like. Hexafluoroisopropyl group, heptafluoroisopropyl group, hexafluoro (2-methyl) isopropyl group, octafluoroisobutyl group, nonafluoro-t-butyl group and perfluoroisopentyl group are preferable, and hexafluoroisopropyl group and heptafluoroisopropyl group are preferable. Further preferred.
Specific examples of the group represented by the general formula (F4) include, for example, —C (CF ₃ ) ₂ OH, —C (C ₂ F ₅ ) ₂ OH, —C (CF ₃ ) (CH ₃ ) OH, -CH _(CF 3) OH and the like, -C _{(CF 3)} 2 OH is preferred.

The resin (D) is preferably a resin having an alkylsilyl structure (preferably a trialkylsilyl group) or a cyclic siloxane structure as a partial structure having a silicon atom.
Specific examples of the alkylsilyl structure or the cyclic siloxane structure include groups represented by the following general formulas (CS-1) to (CS-3).

In general formulas (CS-1) to (CS-3),
R _{12 to} R ₂₆ each independently represents a linear alkyl group (preferably having 1 to 20 carbon atoms), a branched alkyl group or a cycloalkyl group (preferably having 3 to 20 carbon atoms).
L < ₃ > -L < ₅ > represents a single bond or a bivalent coupling group. The divalent linking group is selected from the group consisting of an alkylene group, a phenylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a ureylene group or a urea group, or a combination of two or more groups. Can be mentioned.
n represents an integer of 1 to 5. n is preferably an integer of 2 to 4.

  Examples of the resin (D) include resins having at least one selected from the group of repeating units represented by the following general formulas (CI) to (CV).

In the general formulas (CI) to (CV),
R _{1 to} R ₃ are each independently a hydrogen atom, a fluorine atom, a linear or branched alkyl group (preferably having 1 to 4 carbon atoms) or a linear or branched fluorinated alkyl group (preferably having 1 carbon atom). ~ 4).
W ₁ to _W-2 represents an organic group having at least either a fluorine atom or a silicon atom.
R _{4 to} R ₇ are each independently a hydrogen atom, a fluorine atom, a linear or branched alkyl group (preferably having 1 to 4 carbon atoms) or a linear or branched fluorinated alkyl group (preferably having 1 carbon atom). ~ 4). However, at least one of R _{4 to} R ₇ represents a fluorine atom. R ₄ and R ₅ or R ₆ and R ₇ may form a ring.
R ₈ represents a hydrogen atom or a linear or branched alkyl group (preferably having 1 to 4 carbon atoms).
R ₉ represents a linear or branched alkyl group (preferably having 1 to 4 carbon atoms) or a linear or branched fluorinated alkyl group (preferably having 1 to 4 carbon atoms).
L _{1 to} L ₂ represent a single bond or a divalent linking group, and are the same as L _{3 to} L ₅ described above.
Q represents a monocyclic or polycyclic cyclic aliphatic group. That is, it represents an atomic group that contains two bonded carbon atoms (C—C) and forms an alicyclic structure. Q may have a substituent. The monocyclic aliphatic group as Q is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include a cyclopentyl group, a cyclohexyl group, a cyclobutyl group, and a cyclooctyl group. Examples of the polycyclic aliphatic group as Q include a group having a bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms, and a cycloalkyl group having 6 to 20 carbon atoms is preferable, for example, an adamantyl group , Norbornyl group, dicyclopentyl group, tricyclodecanyl group, tetocyclododecyl group and the like. A part of carbon atoms in the cycloalkyl group may be substituted with a hetero atom such as an oxygen atom.
R ₃₀ and R ₃₁ each independently represent a hydrogen atom or a fluorine atom.
R ₃₂ and R ₃₃ each independently represents an alkyl group, a cycloalkyl group, a fluorinated alkyl group or a fluorinated cycloalkyl group.
However, the repeating unit represented by formula (CV) has at least one fluorine atom in at least one of R ₃₀ , R ₃₁ , R ₃₂ and R ₃₃ .

  The resin (D) preferably has a repeating unit represented by the general formula (CI), and further has a repeating unit represented by the following general formulas (C-Ia) to (C-Id). preferable.

In the general formulas (C-Ia) to (C-Id),
R ₁₀ and R ₁₁ are a hydrogen atom, a fluorine atom, a linear or branched alkyl group (preferably having 1 to 4 carbon atoms), or a linear or branched fluorinated alkyl group (preferably having 1 to 4 carbon atoms). Represents.
W _{3 to} W ₆ represent an organic group having at least one of a fluorine atom and a silicon atom.

When W _{1 to} W ₆ are an organic group having a fluorine atom, a fluorinated linear or branched alkyl group (preferably having a carbon number of 1 to 20), a fluorinated cycloalkyl group (preferably having a carbon number) 3-20) or a fluorinated linear, branched or cyclic alkyl ether group (preferably having 1 to 20 carbon atoms).

Examples of the fluorinated alkyl group of W _{1 to} W ₆ include trifluoroethyl group, pentafluoropropyl group, hexafluoroisopropyl group, hexafluoro (2-methyl) isopropyl group, heptafluorobutyl group, heptafluoroisopropyl group, octafluoro Examples thereof include an isobutyl group, a nonafluorohexyl group, a nonafluoro-t-butyl group, a perfluoroisopentyl group, a perfluorooctyl group, and a perfluoro (trimethyl) hexyl group.

When W _{1 to} W ₆ are organic groups having a silicon atom, it is preferably a group having an alkylsilyl structure or a cyclic siloxane structure. Specific examples include groups represented by the general formulas (CS-1) to (CS-3).

Hereinafter, although the specific example of the repeating unit represented by general formula (CI) is shown, this invention is not limited to this. In the formula, X represents a hydrogen atom, —CH ₃ , —F or —CF ₃ .

The resin (D) is preferably any resin selected from the following (D-1) to (D-6).
(D-1) A resin having a repeating unit (a) having a fluoroalkyl group (preferably having 1 to 4 carbon atoms), more preferably a resin having only a repeating unit (a).
(D-2) A resin having a repeating unit (b) having a trialkylsilyl group or a group having a cyclic siloxane structure, more preferably a resin having only a repeating unit (b).
(D-3) a repeating unit (a) having a fluoroalkyl group (preferably having 1 to 4 carbon atoms), a branched alkyl group (preferably having 4 to 20 carbon atoms), a cycloalkyl group (preferably having 4 to 4 carbon atoms) 20) a repeating unit (c) having a branched alkenyl group (preferably having 4 to 20 carbon atoms), a cycloalkenyl group (preferably having 4 to 20 carbon atoms) or an aryl group (preferably having 4 to 20 carbon atoms). A resin having a repeating unit (a) and a repeating unit (c).
(D-4) a repeating unit (b) having a trialkylsilyl group or a group having a cyclic siloxane structure, a branched alkyl group (preferably having 4 to 20 carbon atoms), a cycloalkyl group (preferably having 4 to 20 carbon atoms) ), A branched alkenyl group (preferably having 4 to 20 carbon atoms), a cycloalkenyl group (preferably having 4 to 20 carbon atoms) or an aryl group (preferably having 4 to 20 carbon atoms) and a repeating unit (c). Resin, more preferably a copolymer resin of repeating unit (b) and repeating unit (c).
(D-5) a resin having a repeating unit (a) having a fluoroalkyl group (preferably having 1 to 4 carbon atoms) and a repeating unit (b) having a trialkylsilyl group or a group having a cyclic siloxane structure; Preferably, a copolymer resin of repeating unit (a) and repeating unit (b).
(D-6) a repeating unit (a) having a fluoroalkyl group (preferably having 1 to 4 carbon atoms), a repeating unit (b) having a trialkylsilyl group or a group having a cyclic siloxane structure, and a branched alkyl group (Preferably 4 to 20 carbon atoms), cycloalkyl group (preferably 4 to 20 carbon atoms), branched alkenyl group (preferably 4 to 20 carbon atoms), cycloalkenyl group (preferably 4 to 20 carbon atoms) or A resin having a repeating unit (c) having an aryl group (preferably having 4 to 20 carbon atoms), more preferably a copolymer resin of the repeating unit (a), the repeating unit (b) and the repeating unit (c).
As the repeating unit (c) having a branched alkyl group, a cycloalkyl group, a branched alkenyl group, a cycloalkenyl group, or an aryl group in the resins (D-3), (D-4), and (D-6) In view of hydrophilicity / hydrophobicity, interaction, etc., an appropriate functional group can be introduced, but from the viewpoints of immersion liquid followability and receding contact angle, a functional group having no polar group is preferred. .
In the resins (D-3), (D-4), and (D-6), a repeating unit (a) having a fluoroalkyl group and / or a repeating unit having a trialkylsilyl group or a group having a cyclic siloxane structure (B) is preferably 20 to 99 mol%.

  The resin (D) is preferably a resin having a repeating unit represented by the following general formula (Ia).

In general formula (Ia):
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₁ represents an alkyl group.
R ₂ represents a hydrogen atom or an alkyl group.

In general formula (Ia), the alkyl group in which at least one hydrogen atom of Rf is substituted with a fluorine atom preferably has 1 to 3 carbon atoms, and more preferably a trifluoromethyl group.
The alkyl group for R ₁ is preferably a linear or branched alkyl group having 3 to 10 carbon atoms, and more preferably a branched alkyl group having 3 to 10 carbon atoms.
R ₂ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, and more preferably a linear or branched alkyl group having 3 to 10 carbon atoms.

  Hereinafter, although the specific example of the repeating unit represented by general formula (Ia) is given, this invention is not limited to this.

  The repeating unit represented by the general formula (Ia) can be formed by polymerizing a compound represented by the following general formula (If).

In the general formula (the If), Rf, _{R 1} and _{R 2} are in the general formula (Ia), Rf, _{R 1} and _{R 2} synonymous.
As the compound represented by the general formula (If), a commercially available product may be used, or a synthesized product may be used. In the case of synthesis, 2-trifluoromethylmethacrylic acid can be obtained by acidification and then esterification.

  The resin (D) having a repeating unit represented by the general formula (Ia) preferably further has a repeating unit represented by the following general formula (IIIF).

In general formula (IIIF):
R ₄ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a trialkylsilyl group, or a group having a cyclic siloxane structure.
L ₆ represents a single bond or a divalent linking group.

In the general formula (IIIF), the alkyl group represented by R ₄ is preferably a linear or branched alkyl group having 3 to 20 carbon atoms.
The cycloalkyl group is preferably a cycloalkyl group having 3 to 20 carbon atoms.
The alkenyl group is preferably an alkenyl group having 3 to 20 carbon atoms.
The cycloalkenyl group is preferably a cycloalkenyl group having 3 to 20 carbon atoms.
The trialkylsilyl group is preferably a trialkylsilyl group having 3 to 20 carbon atoms.
The group having a cyclic siloxane structure is preferably a group having a cyclic siloxane structure having 3 to 20 carbon atoms.
The divalent linking group of L ₆ is preferably an alkylene group (preferably having 1 to 5 carbon atoms) or an oxy group.

  Hereinafter, although the specific example of resin (D) which has a repeating unit represented by general formula (Ia) is given, this invention is not limited to this.

  The resin (D) is preferably a resin having a repeating unit represented by the following general formula (IIF) and a repeating unit represented by the following general formula (IIIF).

In general formulas (IIF) and (IIIF),
Rf represents a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.
R ₃ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, or a group formed by combining two or more thereof.
R ₄ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a trialkylsilyl group, a group having a cyclic siloxane structure, or a group formed by combining two or more thereof.
L ₆ represents a single bond or a divalent linking group.
m and n represent the ratio of repeating units, and 0 <m <100 and 0 <n <100.

Rf in the general formula (IIF) is the same as Rf in the general formula (Ia).
The alkyl group of R ₃ and R ₄ is preferably a linear or branched alkyl group having 3 to 20 carbon atoms.
The cycloalkyl group is preferably a cycloalkyl group having 3 to 20 carbon atoms.
The alkenyl group is preferably an alkenyl group having 3 to 20 carbon atoms.
The cycloalkenyl group is preferably a cycloalkenyl group having 3 to 20 carbon atoms.
The trialkylsilyl group of R ₄ is preferably a C 3-20 trialkylsilyl group.
The group having a cyclic siloxane structure is preferably a group having a cyclic siloxane structure having 3 to 20 carbon atoms.
The alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, and trialkylsilyl group of R ₃ and R ₄ can introduce a functional group, but have a polar group from the viewpoint of following the immersion liquid. The functional group is preferably not substituted, and more preferably unsubstituted.
L ₆ is preferably a single bond, a methylene group, an ethylene group or an ether group.
m = 30 to 70 and n = 30 to 70 are preferable, and m = 40 to 60 and n = 40 to 60 are more preferable.

  Hereinafter, specific examples of the resin (D) having the repeating unit represented by the general formula (IIF) and the repeating unit represented by the general formula (IIIF) will be described, but the present invention is not limited thereto. .

  Resin (D) may have a repeating unit represented by the following general formula (VIII).

In general formula (VIII):
Z ₂ represents —O— or —N (R ₄₁ ) —. R ₄₁ represents a hydrogen atom, a hydroxyl group, an alkyl group, or —OSO ₂ —R ₄₂ . R ₄₂ represents an alkyl group, a cycloalkyl group or a camphor residue. The alkyl group of R ₄₁ and R ₄₂ may be substituted with a halogen atom (preferably a fluorine atom) or the like.

  The resin (D) is preferably solid at room temperature (25 ° C.). Furthermore, it is preferable that glass transition temperature (Tg) is 50-200 degreeC, and 80-160 degreeC is more preferable.

Being solid at 25 ° C. means that the melting point is 25 ° C. or higher.
The glass transition temperature (Tg) can be measured by scanning calorimetry. For example, the specific volume changes when the sample is heated once, cooled and then heated again at 5 ° C./min. It can be measured by analyzing the value.

  The resin (D) is preferably stable to an acid and insoluble in an alkaline developer.

Resin (D) is decomposed by the action of (x) an alkali-soluble group, (y) an alkali (alkaline developer), a group that increases the solubility in the alkali developer and (z) an acid, From the viewpoint of the followability of the immersion liquid, it is preferable not to have a group that increases the solubility in the developer.
The total amount of repeating units having an alkali-soluble group in the resin (D) or a group whose solubility in a developer is increased by the action of an acid or an alkali is preferably 20 with respect to all the repeating units constituting the resin (D). It is not more than mol%, more preferably 0 to 10 mol%, still more preferably 0 to 5 mol%.
In addition, unlike the surfactant generally used in resists, the resin (D) does not have an ionic bond or a hydrophilic group such as a (poly (oxyalkylene)) group. When the resin (D) has a hydrophilic polar group, the followability of immersion water tends to decrease. Therefore, it is more preferable that the resin (D) does not have a polar group selected from a hydroxyl group, an alkylene glycol, and a sulfone group. In addition, it is preferable not to have an ether group bonded to a carbon atom of the main chain through a linking group because hydrophilicity increases and immersion liquid followability deteriorates. On the other hand, an ether group bonded directly to a carbon atom of the main chain as shown by the general formula (IIIF) is preferable because it may express a hydrophobic group.

  (X) Examples of alkali-soluble groups include phenolic hydroxyl groups, carboxyl groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, and (alkylsulfonyl). (Alkylcarbonyl) imide group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris (alkyl And a group having a sulfonyl) methylene group.

  (Y) Examples of the group that decomposes by the action of an alkali (alkaline developer) and increases the solubility in the alkali developer include a lactone group, an ester group, a sulfonamide group, an acid anhydride, and an acid imide group. Can be mentioned.

  (Z) Examples of the group that decomposes by the action of an acid and increases the solubility in a developer include the same groups as the acid-decomposable groups in the resin (A).

  However, the repeating unit represented by the following general formula (pA-c) has no or very little decomposability due to the action of acid as compared with the acid-decomposable group of the resin (A), and is substantially non-acid-decomposable. Considered equivalent to gender.

In the general formula (pA-c),
Rp ₂ represents a hydrocarbon group having a tertiary carbon atom bonded to the oxygen atom in the formula.

  When the resin (D) has a silicon atom, the content of the silicon atom is preferably 2 to 50% by mass and more preferably 2 to 30% by mass with respect to the molecular weight of the resin (D). Moreover, it is preferable that the repeating unit containing a silicon atom is 10-100 mass% in resin (D), and it is more preferable that it is 20-100 mass%.

  When resin (D) has a fluorine atom, the fluorine atom content is preferably 5 to 80% by mass and more preferably 10 to 80% by mass with respect to the molecular weight of resin (D). Moreover, it is preferable that the repeating unit containing a fluorine atom is 10-100 mass% in resin (D), and it is more preferable that it is 30-100 mass%.

  The weight average molecular weight in terms of standard polystyrene of the resin (D) is preferably 1,000 to 100,000, more preferably 1,000 to 50,000, still more preferably 2,000 to 15,000, and particularly preferably. Is 3,000 to 15,000.

  The resin (D) preferably has a residual monomer amount of 0 to 10% by mass, more preferably 0 to 5% by mass, and still more preferably 0 to 1% by mass. The molecular weight distribution (Mw / Mn, also referred to as dispersity) is preferably 1 to 5, more preferably 1 to 3, and still more preferably 1 in terms of resolution, resist shape, resist pattern sidewall, roughness, and the like. It is in the range of ~ 1.5.

  The amount of the resin (D) added in the resist composition is preferably 0.1 to 20% by mass, more preferably 0.1 to 10% by mass, based on the total solid content of the resist composition. preferable. Furthermore, it is preferable that it is 0.1-5 mass%, More preferably, it is 0.2-3.0 mass%, More preferably, it is 0.3-2.0 mass%.

  Resin (D), like resin (A), naturally has few impurities such as metals, but the residual monomer and oligomer components are not more than predetermined values, for example, 0.1% by mass or the like by HPLC. It is preferable that not only the sensitivity, resolution, process stability, pattern shape, etc. as a resist can be further improved, but also a resist composition free from foreign matter in liquid, sensitivity, etc. can be obtained.

  As the resin (D), various commercially available products can be used, or they can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer type and a polymerization initiator are dissolved in a solvent, and a batch polymerization method in which polymerization is performed by heating, a solution of the monomer type and the polymerization initiator is added to the heating solvent over 1 to 10 hours. Examples thereof include a dropping polymerization method which is added dropwise, and a dropping polymerization method is preferred. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate, amide solvents such as dimethylformamide and dimethylacetamide. Furthermore, the solvent which melt | dissolves the composition of this invention like the below-mentioned propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone is mentioned. More preferably, the polymerization is performed using the same solvent as that used in the resist composition of the present invention. Thereby, generation | occurrence | production of the particle at the time of a preservation | save can be suppressed.

  The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As a polymerization initiator, a commercially available radical initiator (azo initiator, peroxide, etc.) is used to initiate the polymerization. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is preferable. Preferred polymerization initiators include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2'-azobis (2-methylpropionate) and the like. A chain transfer agent can also be used as needed. The concentration of solutes such as monomers, polymerization initiators and chain transfer agents in the reaction solution is usually 5 to 50% by mass, preferably 20 to 50% by mass, and more preferably 30 to 50% by mass. The reaction temperature is usually from 10 ° C to 150 ° C, preferably from 30 ° C to 120 ° C, more preferably from 60 ° C to 100 ° C.

  After completion of the reaction, the mixture is allowed to cool to room temperature and purified. Purification can be accomplished by a liquid-liquid extraction method that removes residual monomers and oligomer components by combining water and an appropriate solvent, and a purification method in a solution state such as ultrafiltration that extracts and removes only those having a specific molecular weight or less. , Reprecipitation method that removes residual monomer by coagulating resin in poor solvent by dripping resin solution into poor solvent and purification in solid state such as washing filtered resin slurry with poor solvent A normal method such as a method can be applied. For example, the resin is precipitated as a solid by contacting a solvent (poor solvent) in which the resin is hardly soluble or insoluble in a volume amount of 10 times or less, preferably 10 to 5 times that of the reaction solution.

  The solvent (precipitation or reprecipitation solvent) used in the precipitation or reprecipitation operation from the polymer solution may be a poor solvent for the polymer. For example, hydrocarbon (pentane, hexane, Aliphatic hydrocarbons such as heptane and octane; Cycloaliphatic hydrocarbons such as cyclohexane and methylcyclohexane; Aromatic hydrocarbons such as benzene, toluene and xylene), halogenated hydrocarbons (methylene chloride, chloroform, carbon tetrachloride, etc.) Halogenated aliphatic hydrocarbons; halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene), nitro compounds (nitromethane, nitroethane, etc.), nitriles (acetonitrile, benzonitrile, etc.), ethers (diethyl ether, diisopropyl ether, dimethoxyethane) Chain A Cyclic ethers such as tetrahydrofuran and dioxane), ketones (acetone, methyl ethyl ketone, diisobutyl ketone, etc.), esters (ethyl acetate, butyl acetate, etc.), carbonates (dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, etc.), alcohols ( (Methanol, ethanol, propanol, isopropyl alcohol, butanol, etc.), carboxylic acid (acetic acid, etc.), water, a mixed solvent containing these solvents, and the like. Among these, as a precipitation or reprecipitation solvent, a solvent containing at least an alcohol (particularly methanol or the like) or water is preferable. In such a solvent containing at least alcohol, the ratio of alcohol (particularly methanol, etc.) to other solvent (eg, ester such as ethyl acetate, ether such as tetrahydrofuran) is, for example, the former / the latter (volume ratio; 25 ° C.) = 10/90 to 99/1, preferably the former / the latter (volume ratio; 25 ° C.) = 30/70 to 98/2, more preferably the former / the latter (volume ratio; 25 ° C.) = 50/50 About 97/3.

  The amount of the precipitation or reprecipitation solvent used can be appropriately selected in consideration of efficiency, yield, and the like, but generally 100 to 10000 parts by mass, preferably 200 to 2000 parts by mass with respect to 100 parts by mass of the polymer solution, More preferably, it is 300-1000 mass parts.

  The nozzle diameter at the time of supplying the polymer solution to the precipitation or reprecipitation solvent (poor solvent) is preferably 4 mmφ or less (for example, 0.2 to 4 mmφ). Moreover, the supply speed (dropping speed) of the polymer solution into the poor solvent is, for example, about 0.1 to 10 m / second, preferably about 0.3 to 5 m / second, as the linear speed.

  The precipitation or reprecipitation operation is preferably performed with stirring. As a stirring blade used for stirring, for example, a desk turbine, a fan turbine (including a paddle), a curved blade turbine, an arrow blade turbine, a fiddler type, a bull margin type, an angled blade fan turbine, a propeller, a multistage type, an anchor type (or Horseshoe type), gate type, double ribbon, screw, etc. can be used. Stirring is preferably further performed for 10 minutes or more, particularly 20 minutes or more after the supply of the polymer solution. When the stirring time is short, the monomer content in the polymer particles may not be sufficiently reduced. Further, the polymer solution and the poor solvent can be mixed and stirred using a line mixer instead of the stirring blade.

  The temperature for precipitation or reprecipitation can be appropriately selected in consideration of efficiency and operability, but is usually about 0 to 50 ° C., preferably around room temperature (for example, about 20 to 35 ° C.). The precipitation or reprecipitation operation can be performed by a known method such as a batch method or a continuous method using a conventional mixing vessel such as a stirring tank.

  The precipitated or re-precipitated particulate polymer is usually subjected to conventional solid-liquid separation such as filtration and centrifugation, and dried before use. Filtration is performed using a solvent-resistant filter medium, preferably under pressure. Drying is performed at a temperature of about 30 to 100 ° C., preferably about 30 to 50 ° C. under normal pressure or reduced pressure (preferably under reduced pressure).

In addition, once the resin is precipitated and separated, it may be dissolved again in a solvent, and the resin may be brought into contact with a hardly soluble or insoluble solvent.
That is, after completion of the radical polymerization reaction, a solvent in which the polymer is hardly soluble or insoluble is brought into contact, the resin is precipitated (step a), the resin is separated from the solution (step b), and dissolved again in the solvent. (Step c), and then contact the resin solution A with a solvent in which the resin is hardly soluble or insoluble in a volume amount less than 10 times that of the resin solution A (preferably 5 times or less volume). This may be a method including precipitating a resin solid (step d) and separating the precipitated resin (step e).
The solvent used in the preparation of the resin solution A can be the same solvent as the solvent that dissolves the monomer in the polymerization reaction, and may be the same as or different from the solvent used in the polymerization reaction.

(E) Basic compound The resist composition of the present invention preferably contains (E) a basic compound in order to reduce a change in performance over time from exposure to heating.
Preferred examples of the basic compound include compounds having structures represented by the following formulas (A) to (E).

In general formulas (A) and (E),
R ²⁰⁰ , R ²⁰¹ and R ²⁰² may be the same or different and are a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (having a carbon number). 6-20), wherein R ²⁰¹ and R ²⁰² may combine with each other to form a ring. R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ may be the same or different and each represents an alkyl group having 1 to 20 carbon atoms.
About the said alkyl group, as an alkyl group which has a substituent, a C1-C20 aminoalkyl group, a C1-C20 hydroxyalkyl group, or a C1-C20 cyanoalkyl group is preferable.
The alkyl groups in the general formulas (A) and (E) are more preferably unsubstituted.

  Preferred compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, piperidine and the like, and more preferred compounds include imidazole structure, diazabicyclo structure, onium hydroxide structure, onium carboxylate Examples thereof include a compound having a structure, a trialkylamine structure, an aniline structure or a pyridine structure, an alkylamine derivative having a hydroxyl group and / or an ether bond, and an aniline derivative having a hydroxyl group and / or an ether bond.

  Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, and benzimidazole. Examples of the compound having a diazabicyclo structure include 1,4-diazabicyclo [2,2,2] octane, 1,5-diazabicyclo [4,3,0] non-5-ene, and 1,8-diazabicyclo [5,4. 0] Undecaker 7-ene and the like. Examples of the compound having an onium hydroxide structure include triarylsulfonium hydroxide, phenacylsulfonium hydroxide, sulfonium hydroxide having a 2-oxoalkyl group, specifically, triphenylsulfonium hydroxide, tris (t-butylphenyl). Examples include sulfonium hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide, and 2-oxopropylthiophenium hydroxide. As a compound which has an onium carboxylate structure, the anion part of the compound which has an onium hydroxide structure turns into carboxylate, For example, an acetate, an adamantane 1-carboxylate, a perfluoroalkyl carboxylate etc. are mentioned. Examples of the compound having a trialkylamine structure include tri (n-butyl) amine and tri (n-octyl) amine. Examples of the compound having an aniline structure include 2,6-diisopropylaniline, N, N-dimethylaniline, N, N-dibutylaniline, N, N-dihexylaniline and the like. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, and tris (methoxyethoxyethyl) amine. Examples of aniline derivatives having a hydroxyl group and / or an ether bond include N, N-bis (hydroxyethyl) aniline.

Preferred examples of the basic compound further include an amine compound having a phenoxy group, an ammonium salt compound having a phenoxy group, an amine compound having a sulfonic acid ester group, and an ammonium salt compound having a sulfonic acid ester group.
The amine compound having a phenoxy group, the ammonium salt compound having a phenoxy group, the amine compound having a sulfonate group, and the ammonium salt compound having a sulfonate group have at least one alkyl group bonded to a nitrogen atom. Is preferred. The alkyl chain preferably has an oxygen atom and an oxyalkylene group is formed. The number of oxyalkylene groups is 1 or more, preferably 3 to 9, more preferably 4 to 6 in the molecule. _-CH 2 _CH 2 O Among the oxyalkylene group _{-, - CH (CH 3)} CH 2 O- or _-CH 2 _CH 2 _CH 2 O- structure is preferred.
Specific examples of the amine compound having a phenoxy group, an ammonium salt compound having a phenoxy group, an amine compound having a sulfonic acid ester group, and an ammonium salt compound having a sulfonic acid ester group include US Patent Application Publication No. 2007/0224539. The compounds (C1-1) to (C3-3) exemplified in [0066] are not limited thereto. These basic compounds are used alone or in combination of two or more.

  The usage-amount of a basic compound is 0.001-10 mass% normally based on solid content of a resist composition, Preferably it is 0.01-5 mass%.

  The use ratio of the acid generator and the basic compound in the composition is preferably acid generator / basic compound (molar ratio) = 2.5 to 300. In other words, the molar ratio is preferably 2.5 or more from the viewpoint of sensitivity and resolution, and is preferably 300 or less from the viewpoint of suppressing the reduction in resolution due to the thickening of the resist pattern over time until post-exposure heat treatment. The acid generator / basic compound (molar ratio) is more preferably 5.0 to 200, still more preferably 7.0 to 150.

(F) Surfactant The resist composition of the present invention may or may not further contain a surfactant. When it is contained, fluorine and / or silicon surfactant (fluorine surfactant, silicon surfactant) It is more preferable to contain any one of surfactants, surfactants having both fluorine atoms and silicon atoms, or two or more thereof.

  When the resist composition of the present invention contains a surfactant, it is possible to provide a resist pattern with less adhesion and development defects with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. It becomes. Examples of the fluorine-based and / or silicon-based surfactant include surfactants described in [0276] of US Patent Application Publication No. 2008/0248425. For example, F-top EF301, EF303, (Shin-Akita Kasei Co., Ltd.) )), FLORARD FC430, 431, 4430 (manufactured by Sumitomo 3M Co., Ltd.), Megafac F171, F173, F176, F189, F113, F110, F177, F120, R08 (manufactured by Dainippon Ink & Chemicals, Inc.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (manufactured by Asahi Glass Co., Ltd.), Troisol S-366 (manufactured by Troy Chemical Co., Ltd.), GF-300, GF-150 (Toagosei Chemical Co., Ltd.) ), Surflon S-393 (Seimi Chemical Co., Ltd.), F-top EF121, E 122A, EF122B, RF122C, EF125M, EF135M, EF351, EF352, EF801, EF802, EF601 (manufactured by Gemco), PF636, PF656, PF6320, PF6520 (manufactured by OMNOVA), FTX-204G, 230G, 218G, 218G 204D, 208D, 212D, 218D, 222D (manufactured by Neos Co., Ltd.) and the like. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

In addition to the known surfactants described above, surfactants are derived from fluoroaliphatic compounds produced by the telomerization method (also referred to as the telomer method) or the oligomerization method (also referred to as the oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.
As the surfactant corresponding to the above, Megafac F178, F-470, F-473, F-475, F-476, F-472 (manufactured by Dainippon Ink & Chemicals, Inc.), C ₆ F ₁₃ group Copolymer of acrylate (or methacrylate) and (poly (oxyalkylene)) acrylate (or methacrylate), acrylate (or methacrylate) and (poly (oxyethylene)) acrylate (or methacrylate) having a C ₃ F ₇ group And a copolymer of (poly (oxypropylene)) acrylate (or methacrylate).

  In the present invention, surfactants other than fluorine-based and / or silicon-based surfactants described in [0280] of US Patent Application Publication No. 2008/0248425 can also be used.

  These surfactants may be used alone or in several combinations.

When the resist composition contains a surfactant, the amount of the surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.0005 to the total amount of the resist composition (excluding the solvent). 1% by mass.
On the other hand, by making the addition amount of the surfactant 10 ppm or less with respect to the total amount of the resist composition (excluding the solvent), the surface unevenness of the hydrophobic resin is improved, thereby making the resist film surface more hydrophobic. It is possible to improve the water followability at the time of immersion exposure.

(G) Onium carboxylate The resist composition in the present invention may contain an onium carboxylate. Examples of such carboxylic acid onium salts include those described in US Patent Application Publication No. 2008/0187860 [0605] to [0606].

  These carboxylic acid onium salts can be synthesized by reacting sulfonium hydroxide, iodonium hydroxide, ammonium hydroxide and carboxylic acid with silver oxide in a suitable solvent.

  The content of the carboxylic acid onium salt in the composition is generally 0.1 to 20% by mass, preferably 0.5 to 10% by mass, more preferably 1 to 7% by mass, based on the total solid content of the composition. %.

(H) Other additives The resist composition of the present invention further promotes solubility in dyes, plasticizers, photosensitizers, light absorbers, alkali-soluble resins, dissolution inhibitors and developers as necessary. The compound to be made (for example, a phenol compound having a molecular weight of 1000 or less, an alicyclic compound having a carboxyl group, or an aliphatic compound) and the like can be contained.

Such phenolic compounds having a molecular weight of 1000 or less can be obtained by referring to, for example, the methods described in JP-A-4-1222938, JP-A-2-28531, US Pat. No. 4,916,210, European Patent 219294, etc. It can be easily synthesized by those skilled in the art.
Specific examples of alicyclic or aliphatic compounds having a carboxyl group include carboxylic acid derivatives having a steroid structure such as cholic acid, deoxycholic acid, lithocholic acid, adamantane carboxylic acid derivatives, adamantane dicarboxylic acid, cyclohexane carboxylic acid, cyclohexane Examples thereof include, but are not limited to, dicarboxylic acids.

The solid content concentration of the resist composition of the present invention is usually 1.0 to 10% by mass, preferably 2.0 to 5.7% by mass, and more preferably 2.0 to 5.3% by mass. . By setting the solid content concentration within the above range, it is possible to uniformly apply the resist solution on the substrate and to form a resist pattern having excellent line edge roughness. The reason for this is not clear, but perhaps the solid content concentration is 10% by mass or less, preferably 5.7% by mass or less, which suppresses aggregation of the material in the resist solution, particularly the photoacid generator. As a result, it is considered that a uniform resist film was formed.
The solid content concentration is a weight percentage of the weight of other resist components excluding the solvent with respect to the total weight of the resist composition.

  In the pattern forming method of the present invention, a step of forming a film with a resin composition whose solubility in a negative developer is reduced by irradiation with actinic rays or radiation, a step of exposing the film, a step of heating, and a positive The step of mold development can be performed by a generally known method.

The light source wavelength limit is not used for the exposure apparatus in the present invention, KrF excimer laser wavelength (248 nm), ArF excimer laser wavelength and (193 nm) _{F 2} can be applied to excimer laser wavelength (157 nm) or the like.

Moreover, the immersion exposure method can be applied in the step of performing exposure according to the present invention.
The immersion exposure method is a technology for filling and exposing a projection lens and a sample with a liquid having a high refractive index (hereinafter also referred to as “immersion liquid”) as a technique for increasing the resolving power.
As described above, this “immersion effect” means that λ ₀ is the wavelength of the exposure light in the air, n is the refractive index of the immersion liquid with respect to the air, θ is the convergence angle of the light beam, and NA ₀ = sin θ. When immersed, the resolving power and the depth of focus can be expressed by the following equations. Here, k ₁ and k ₂ are coefficients related to the process.
(Resolving power) = k ₁ · (λ ₀ / n) / NA ₀
(Depth of focus) = ± k ₂ · (λ ₀ / n) / NA ₀ ²
That is, the immersion effect is equivalent to using an exposure wavelength having a wavelength of 1 / n. In other words, in the case of a projection optical system with the same NA, the depth of focus can be increased n times by immersion. This is effective for all pattern shapes, and can be combined with a super-resolution technique such as a phase shift method and a modified illumination method which are currently being studied.

  When performing immersion exposure, (1) after forming the film on the substrate, before the exposure step and / or (2) after exposing the film via the immersion liquid, Prior to the heating step, a step of washing the surface of the membrane with an aqueous chemical may be performed.

  The immersion liquid is preferably a liquid that is transparent to the exposure wavelength and has a refractive index temperature coefficient as small as possible so as to minimize distortion of the optical image projected onto the film. In the case of an ArF excimer laser (wavelength: 193 nm), it is preferable to use water from the viewpoints of availability and ease of handling in addition to the above-described viewpoints.

When water is used, an additive (liquid) that decreases the surface tension of water and increases the surface activity may be added in a small proportion. This additive is preferably one that does not dissolve the resist layer on the wafer and can ignore the influence on the optical coating on the lower surface of the lens element.
As such an additive, for example, an aliphatic alcohol having a refractive index substantially equal to that of water is preferable, and specific examples include methyl alcohol, ethyl alcohol, isopropyl alcohol and the like. By adding an alcohol having a refractive index substantially equal to that of water, even if the alcohol component in water evaporates and the content concentration changes, an advantage that the change in the refractive index of the entire liquid can be made extremely small can be obtained.

  On the other hand, when an opaque substance or impurities whose refractive index is significantly different from that of water are mixed with respect to 193 nm light, the optical image projected on the resist is distorted. Therefore, distilled water is preferable as the water to be used. Further, pure water filtered through an ion exchange filter or the like may be used.

In the present invention, the substrate on which the film is formed is not particularly limited, and silicon, SiN, inorganic substrates such as SiO ₂ and SiN, coated inorganic substrates such as SOG, semiconductor manufacturing processes such as IC, liquid crystal, and thermal head For example, a substrate generally used in a circuit board manufacturing process or other photofabrication lithography process can be used. Further, if necessary, an organic antireflection film may be formed between the film and the substrate.

When performing positive development, an alkali developer is preferably used.
Examples of the alkaline developer used for positive development include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, ethylamine, and n-propylamine. Secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, and tetramethylammonium hydroxide Alkaline aqueous solutions such as quaternary ammonium salts such as tetraethylammonium hydroxide and cyclic amines such as pyrrole and pihelidine can be used.
Furthermore, an appropriate amount of alcohol or surfactant may be added to the alkaline aqueous solution.
The alkali concentration of the alkali developer is usually from 0.1 to 20% by mass.
The pH of the alkali developer is usually from 10.0 to 15.0.
In particular, an aqueous solution of 2.38% by mass of tetramethylammonium hydroxide is desirable.

  As the rinsing liquid in the rinsing treatment performed after the positive development, pure water can be used and an appropriate amount of a surfactant can be added.

When performing negative development, it is preferable to use an organic developer containing an organic solvent.
As an organic developer that can be used in negative development, polar solvents such as ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents can be used. .
Examples of the ketone solvent include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, and methyl ethyl ketone. Methyl isobutyl ketone, acetyl acetone, acetonyl acetone, ionone, diacetyl alcohol, acetyl carbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, and the like.
Examples of the ester solvent include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3- Examples include ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, and propyl lactate.
Examples of the alcohol solvent include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, alcohols such as n-octyl alcohol and n-decanol, glycol solvents such as ethylene glycol, diethylene glycol and triethylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, Diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methoxymethyl butano It can be mentioned glycol ether solvents such as Le.
Examples of the ether solvent include dioxane, tetrahydrofuran and the like in addition to the glycol ether solvent.
Examples of the amide solvent include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, hexamethylphosphoric triamide, 1,3-dimethyl-2-imidazolidinone and the like. Can be used.
Examples of the hydrocarbon solvent include aromatic hydrocarbon solvents such as toluene and xylene, and aliphatic hydrocarbon solvents such as pentane, hexane, octane and decane.
A plurality of the above solvents may be mixed, or may be used by mixing with a solvent other than the above or water. However, in order to fully exhibit the effects of the present invention, the water content of the developer as a whole is preferably less than 10% by mass, and more preferably substantially free of moisture.
That is, the amount of the organic solvent used in the organic developer is preferably 90% by mass or more and 100% by mass or less, and more preferably 95% by mass or more and 100% by mass or less, with respect to the total amount of the developer.
In particular, the negative developer is preferably a developer containing at least one solvent selected from ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents.

The vapor pressure of the negative developer is preferably 5 kPa or less, more preferably 3 kPa or less, and particularly preferably 2 kPa or less at 20 ° C. By setting the vapor pressure of the negative developer to 5 kPa or less, evaporation of the developer on the substrate or in the developing cup is suppressed, and the temperature uniformity in the wafer surface is improved. As a result, the dimensions in the wafer surface are uniform. Sexuality improves.
Specific examples having a vapor pressure of 5 kPa or less include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, 4-heptanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl Ketone solvents such as isobutyl ketone, butyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxy Esters such as butyl acetate, 3-methyl-3-methoxybutyl acetate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate Agents, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, n-octyl alcohol, n-decanol, etc. Solvents, glycol solvents such as ethylene glycol, diethylene glycol, triethylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, Glycol ether solvents such as methoxymethylbutanol, solvents such as tetrahydrofuran Solvent, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide amide solvent, toluene, xylene and other aromatic hydrocarbon solvents, octane, decane and other aliphatic carbonization A hydrogen solvent is mentioned.
Specific examples having a vapor pressure of 2 kPa or less, which is a particularly preferable range, include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, 4-heptanone, 2-hexanone, diisobutyl ketone, cyclohexanone, and methylcyclohexanone. , Ketone solvents such as phenylacetone, butyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3- Ester solvents such as methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, ethyl lactate, butyl lactate and propyl lactate, n-butyl alcohol, alcohol solvents such as ec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, n-octyl alcohol and n-decanol; glycol solvents such as ethylene glycol, diethylene glycol and triethylene glycol And glycol ether solvents such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methoxymethylbutanol, N-methyl-2 Amide solvents of pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, Aromatic hydrocarbon solvents such as cyclohexylene, octane, aliphatic hydrocarbon solvents decane.

An appropriate amount of a surfactant can be added to the developer that can be used for negative development, if necessary.
The surfactant is not particularly limited, and for example, ionic or nonionic fluorine-based and / or silicon-based surfactants can be used. Examples of these fluorine and / or silicon surfactants include, for example, JP-A No. 62-36663, JP-A No. 61-226746, JP-A No. 61-226745, JP-A No. 62-170950, JP 63-34540 A, JP 7-230165 A, JP 8-62834 A, JP 9-54432 A, JP 9-5988 A, US Pat. No. 5,405,720, etc. The surfactants described in US Pat. Nos. 5,360,692, 5,529,881, 5,296,330, 5,346,098, 5,576,143, 5,294,511, and 5,824,451 can be mentioned. Preferably, it is a nonionic surfactant. Although it does not specifically limit as a nonionic surfactant, It is still more preferable to use a fluorochemical surfactant or a silicon-type surfactant.
The amount of the surfactant used is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass with respect to the total amount of the developer.

As a developing method, for example, a method in which a substrate is immersed in a tank filled with a developer for a certain period of time (dip method), a method in which the developer is raised on the surface of the substrate by surface tension and is left stationary for a certain time (paddle) Method), a method of spraying the developer on the substrate surface (spray method), a method of continuously discharging the developer while scanning the developer discharge nozzle on the substrate rotating at a constant speed (dynamic dispensing method) Etc. can be applied.
When the various development methods described above include a step of discharging the developer from the developing nozzle of the developing device toward the resist film, the discharge pressure of the discharged developer (the flow rate per unit area of the discharged developer) is Preferably it is 2 mL / sec / mm ² or less, More preferably, it is 1.5 mL / sec / mm ² or less, More preferably, it is 1 mL / sec / mm ² or less. There is no particular lower limit on the flow rate, but 0.2 mL / sec / mm ² or more is preferable in consideration of throughput.
By setting the discharge pressure of the discharged developer to be in the above range, pattern defects derived from the resist residue after development can be remarkably reduced.
The details of this mechanism are not clear, but perhaps by setting the discharge pressure within the above range, the pressure applied by the developer to the resist film will decrease, and the resist film / resist pattern may be inadvertently cut or collapsed. This is considered to be suppressed.
The developer discharge pressure (mL / sec / mm ² ) is a value at the developing nozzle outlet in the developing device.

  Examples of the method for adjusting the discharge pressure of the developer include a method for adjusting the discharge pressure with a pump and the like, and a method for changing the pressure by adjusting the pressure by supplying from a pressurized tank.

  Further, after the step of performing the negative development, a step of stopping the development may be performed while substituting with another solvent.

  After the negative development, it is preferable to include a step of washing with a negative development rinsing solution containing an organic solvent.

  The rinsing liquid used in the rinsing step after negative development is not particularly limited as long as the resist pattern is not dissolved, and a solution containing a general organic solvent can be used. As the rinsing liquid, it is preferable to use a rinsing liquid containing at least one organic solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents. . More preferably, after the negative development, a cleaning step is performed using a rinsing liquid containing at least one organic solvent selected from a ketone solvent, an ester solvent, an alcohol solvent, and an amide solvent. Even more preferably, after negative development, a step of washing with a rinse solution containing an alcohol solvent or an ester solvent is performed. Even more preferably, after negative development, a step of washing with a rinsing solution containing a monohydric alcohol is performed. Particularly preferably, after the negative development, a cleaning step is performed using a rinsing solution containing a monohydric alcohol having 5 or more carbon atoms. Here, examples of the monohydric alcohol used in the rinsing step after the negative development include linear, branched, and cyclic monohydric alcohols. Specifically, 1-butanol, 2-butanol, 3- Methyl-1-butanol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 1-hexanol, 4-methyl-2-pentanol, 1-heptanol, 1-octanol, 2-hexanol, cyclopentanol, 2 -Heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol and the like can be used, and particularly preferable monohydric alcohols having 5 or more carbon atoms include 1-hexanol, 2-hexanol, 4-methyl-2-pentanol, 1-pentanol, 3-methyl-1-butanol It can be used.

  A plurality of these components may be mixed, or may be used by mixing with an organic solvent other than the above.

  The water content in the rinse liquid is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less. By setting the water content to 10% by mass or less, good development characteristics can be obtained.

  The vapor pressure of the rinsing liquid used after negative development is preferably 0.05 kPa or more and 5 kPa or less, more preferably 0.1 kPa or more and 5 kPa or less, and most preferably 0.12 kPa or more and 3 kPa or less at 20 ° C. By setting the vapor pressure of the rinse liquid to 0.05 kPa or more and 5 kPa or less, the temperature uniformity in the wafer surface is improved, and further, the swelling due to the penetration of the rinse solution is suppressed, and the dimensional uniformity in the wafer surface. Improves.

  An appropriate amount of a surfactant can be added to the rinse solution.

  In the rinsing step, the wafer that has been subjected to negative development is cleaned using a rinsing solution containing the organic solvent. The cleaning method is not particularly limited. For example, a method of continuing to discharge the rinse liquid onto the substrate rotating at a constant speed (rotary coating method), or immersing the substrate in a tank filled with the rinse liquid for a certain period of time. A method (dip method), a method of spraying a rinsing liquid on the substrate surface (spray method), and the like can be applied. Among them, a cleaning process is performed by a spin coating method, and after cleaning, the substrate is rotated at 2000 rpm to 4000 rpm. It is preferable to rotate and remove the rinse liquid from the substrate. It is also preferable to include a heating step (Post Bake) after the rinsing step. The developing solution and the rinsing solution remaining between the patterns and inside the patterns are removed by baking. The heating step after the rinsing step is usually 40 to 160 ° C., preferably 70 to 95 ° C., and usually 10 seconds to 3 minutes, preferably 30 seconds to 90 seconds.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these.

Synthesis Example 1 (Synthesis of Resin (1))
Under a nitrogen stream, 20 g of a 6/4 (mass ratio) mixed solvent of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether was placed in a three-necked flask and heated to 80 ° C. (solvent 1). The following compound (1-A), the following compound (1-B), the following compound (1-C) and the following compound (1-D) in a molar ratio of 40/10/40/10 in propylene glycol monomethyl ether acetate, It melt | dissolved in the mixed solvent of 6/4 (mass ratio) of propylene glycol monomethyl ether, and prepared 22 mass% monomer solution (200g). Furthermore, 8 mol% of polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) was added to the monomer, and a dissolved solution was added dropwise to the solvent 1 over 6 hours. After completion of dropping, the reaction was further continued at 80 ° C. for 2 hours. The reaction solution was allowed to cool and then poured into 1800 ml of hexane / 200 ml of ethyl acetate. The precipitated powder was collected by filtration and dried to obtain 37 g of Resin (1). The obtained resin (1) had a weight average molecular weight of 10,000 and a dispersity (Mw / Mn) of 1.4.

  Resins (2) to (67) and hydrophobic resin (1a) in the same manner as in Synthesis Example 1 except that monomers corresponding to each repeating unit were used so as to have a desired composition ratio (molar ratio). ~ (4b) was synthesized. Here, the hydrophobic resins (1a) to (4b) correspond to the resin (D).

  Hereinafter, the structures of the resins (2) to (67) and the resins (1a) to (4b) are shown. Moreover, including the above-mentioned resin (1), the composition ratio (molar ratio), weight average molecular weight, and dispersity of the resins (2) to (67) and the resins (1a) to (4b) are shown in Tables 1 and 2. Shown in

Synthesis Example 2 (Synthesis of Compound (PAG-1))
The compound (PAG-1) was synthesized according to [0108] to [0110] of JP2007-161707A.
Compounds (PAG-2) to (PAG-6) and (PAG-8) to (PAG-20) were also synthesized according to the same method. In addition, CGI * 1907 (made by Ciba Specialty Chemicals) was used for the compound (PAG-7).

  Hereinafter, the structures of the compounds (PAG-1) to (PAG-20) are shown.

<Preparation of resist composition>
The components shown in Tables 3 and 4 below are dissolved in the solvents shown in Tables 3 and 4 to prepare solutions with a solid content concentration of 4% by mass, and each is filtered through a polyethylene filter having a pore size of 0.03 μm. Compositions (Ar-1) to (Ar-77) and (Ref-Ar-01) to (Ref-Ar-03) were prepared.

  Abbreviations in Table 3 and Table 4 are as follows.

  B-1 to B-8: each represents the following compound.

W-1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.) (fluorine and silicon)
W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) (silicon-based)

A1: Propylene glycol monomethyl ether acetate (PGMEA, also known as 1-methoxy-2-acetoxypropane)
A2: γ-butyrolactone A3: Cyclohexanone B1: Propylene glycol monomethyl ether (PGME, also known as 1-methoxy-2-propanol)
B2: Ethyl lactate

  A resist pattern was formed by the following method using the prepared resist composition.

Example 1 (one-time exposure → negative development: abbreviation E-B-N)
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied on a silicon wafer, and baked at 205 ° C. for 60 seconds to form an antireflection film having a thickness of 86 nm. A resist composition Ar-01 was applied thereon, and baked at 115 ° C. for 60 seconds to form a resist film having a thickness of 100 nm. Using an ArF excimer laser scanner (PAS5500 / 1100, NA0.75, Dipole, σo / σi = 0.89 / 0.65) manufactured by ASML, an exposure mask (line / space = 1/1) was obtained. Used for pattern exposure. After heating at 105 ° C. for 60 seconds, paddle with a negative developer for 30 seconds to develop (negative development), paddle with a rinse solution for 30 seconds and rinse, and then a wafer is rotated at 4000 rpm for 30 seconds. By rotating, a 100 nm (1: 1) line and space resist pattern was obtained.

Examples 2-67, 74-83 and Comparative Examples 1-3
A resist pattern having a pitch of 200 nm and a line width of 100 nm was obtained in the same manner as in Example 1 except that the resists and conditions described in Tables 5 and 6 were employed. However, the comparative example 3 could not be resolved.

Example 68 (single exposure → positive development → negative development: abbreviation E-B-P-N)
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied on a silicon wafer, and baked at 205 ° C. for 60 seconds to form an antireflection film having a thickness of 86 nm. A resist composition Ar-01 was applied thereon, and baked at 115 ° C. for 60 seconds to form a resist film having a thickness of 100 nm. Using an ArF excimer laser scanner (PAS5500 / 1100, NA0.75, Dipole, σo / σi = 0.89 / 0.65) manufactured by ASML, an exposure mask (line / space = 1/1) was obtained. Then, pattern exposure was performed. After heating at 105 ° C. for 60 seconds, paddle development (positive development) with tetramethylammonium hydroxide aqueous solution (2.38 mass%) (positive developer) for 30 seconds, and paddle with pure water for 30 seconds. Then, a pattern having a pitch of 480 nm and a line width of 360 nm was obtained. Next, paddle development is performed with a negative developer for 30 seconds (negative development), paddle is rinsed with a rinse solution for 30 seconds, and then the wafer is rotated at 4000 rpm for 30 seconds to obtain 100 nm (1 1) Line and space resist pattern was obtained.

Comparative Example 4
A resist pattern having a pitch of 200 nm and a line width of 100 nm was obtained in the same manner as in Example 68 except that the resists and conditions shown in Table 6 were employed.

Example 69 (Single exposure → negative development → positive development: abbreviation E-B-N-P)
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied on a silicon wafer, and baked at 205 ° C. for 60 seconds to form an antireflection film having a thickness of 86 nm. A resist composition Ar-01 was applied thereon and baked at 115 ° C. for 60 seconds to form a resist film having a thickness of 150 nm. Using an ArF excimer laser scanner (PAS5500 / 1100, NA0.75, Dipole, σo / σi = 0.89 / 0.65) manufactured by ASML, an exposure mask (line / space = 1/1) was obtained. Then, pattern exposure was performed. After heating at 105 ° C. for 60 seconds, paddle with a negative developer for 30 seconds to develop (negative development), paddle with a rinse solution for 30 seconds and rinse, and then a wafer is rotated at 4000 rpm for 30 seconds. By rotating, a pattern having a pitch of 400 nm and a line width of 300 nm was obtained. Next, development was performed by paddle with a tetramethylammonium hydroxide aqueous solution (2.38% by mass) (positive developer) for 30 seconds (positive development), paddle with pure water for 30 seconds, and rinsed to 100 nm ( A 1) line and space resist pattern was obtained.

Comparative Example 5
A resist pattern having a pitch of 200 nm and a line width of 100 nm was obtained in the same manner as in Example 69 except that the resists and conditions shown in Table 6 were employed.

Example 70 (double exposure → negative development: abbreviation E-E-B-N)
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied on a silicon wafer, and baked at 205 ° C. for 60 seconds to form an antireflection film having a thickness of 86 nm. A resist composition Ar-01 was applied thereon and baked at 115 ° C. for 60 seconds to form a resist film having a thickness of 150 nm. Using an ArF excimer laser scanner (PAS5500 / 1100, NA0.75, Dipole, σo / σi = 0.89 / 0.65) manufactured by ASML, an exposure mask (line / space = 1/1) was obtained. Then, a first pattern exposure was performed. Next, the mask was rotated in a direction orthogonal to the first exposure, and a second pattern exposure was performed through this. After heating at 105 ° C. for 60 seconds, paddle with a negative developer for 30 seconds to develop (negative development), paddle with a rinse solution for 30 seconds and rinse, and then a wafer is rotated at 4000 rpm for 30 seconds. By rotating, a hole pattern having a pitch of 200 nm and a hole diameter of 100 nm was obtained.

Example 71 (Single exposure → bake → positive development → bake → negative development: abbreviation E-B-P-B-N)
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied on a silicon wafer, and baked at 205 ° C. for 60 seconds to form an antireflection film having a thickness of 86 nm. A resist composition Ar-05 was applied thereon and baked at 115 ° C. for 60 seconds to form a resist film having a thickness of 150 nm. Using an ArF excimer laser scanner (PAS5500 / 1100, NA0.75, Dipole, σo / σi = 0.89 / 0.65) manufactured by ASML, an exposure mask (line / space = 1/1) was obtained. Then, a first pattern exposure was performed. After heating at 95 ° C. for 60 seconds, paddle development (positive development) with tetramethylammonium hydroxide aqueous solution (2.38 mass%) (positive developer) for 30 seconds, and paddle with pure water for 30 seconds. Then, a pattern having a pitch of 400 nm and a line width of 300 nm was obtained. Next, after heating at 105 ° C. for 60 seconds, paddle with negative developer for 30 seconds to develop (negative development), paddle with rinse solution for 30 seconds, rinse, and then rotate at 4000 rpm for 30 seconds. By rotating the wafer, a 100 nm (1: 1) line-and-space resist pattern was obtained.

Example 72 (Single exposure → Bake → Negative development → Bake → Positive development: abbreviation E-B-N-B-P)
An organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied on a silicon wafer, and baked at 205 ° C. for 60 seconds to form an antireflection film having a thickness of 86 nm. A resist composition Ar-06 was applied thereon and baked at 115 ° C. for 60 seconds to form a resist film having a thickness of 150 nm. Using an ArF excimer laser scanner (PAS5500 / 1100, NA0.75, Dipole, σo / σi = 0.89 / 0.65) manufactured by ASML, an exposure mask (line / space = 1/1) was obtained. Then, a first pattern exposure was performed. After heating at 95 ° C. for 60 seconds, paddle development with a negative developer for 30 seconds (negative development), paddle with pure water for 30 seconds and rinse to obtain a pattern with a pitch of 400 nm and a line width of 300 nm. It was. Next, after heating at 105 ° C. for 60 seconds, paddle development with a tetramethylammonium hydroxide aqueous solution (2.38 mass%) (positive developer) for 30 seconds (positive development), and 30 with a rinse solution. After paddling for 2 seconds and rinsing, the wafer was rotated at 4000 rpm for 30 seconds to obtain a 100 nm (1: 1) line-and-space resist pattern.

Example 73 (Single immersion exposure → negative development: abbreviation iE-B-N)
An organic antireflection film ARC29SR (manufactured by Nissan Chemical Industries, Ltd.) was applied on a silicon wafer, and baked at 205 ° C. for 60 seconds to form an antireflection film having a thickness of 95 nm. A resist composition Ar-01 was applied thereon and baked at 115 ° C. for 60 seconds to form a resist film having a thickness of 150 nm. The obtained wafer was exposed using an ArF excimer laser immersion scanner (XTML1700i, NA1.20, C-Quad, outer sigma 0.981, inner sigma 0.895, XY deflection manufactured by ASML) (line / space = 1/1), pattern exposure was performed. Pure water was used as the immersion liquid. After heating at 105 ° C. for 60 seconds, paddle with a negative developer for 30 seconds to develop (negative development), paddle with a rinse solution for 30 seconds and rinse, and then a wafer is rotated at 2000 rpm for 30 seconds. By rotating, a pattern with a pitch of 110 nm and a line width of 55 nm was obtained.

Comparative Example 6
A resist pattern having a pitch of 110 nm and a line width of 55 nm was obtained in the same manner as in the method of Example 73 except that the resists and conditions described in the table were used.

  In Tables 5 and 6, PB means heating before exposure, and PEB means heating after exposure. In the columns of PB, first PEB and second PEB, for example, “115C60s” means heating at 115 ° C. for 60 seconds. A1, A3 and B1 in the negative developer represent the solvents described above. “Negative developer ratio (1) / (2)” and “Rinse solution ratio (1) / (2)” are both mass ratios.

<Evaluation method>
[Line width roughness (LWR)]
100 nm (1: 1) line and space (however, with respect to Example 73 and Comparative Example 6, 55 nm (1: 1) line and space) resist pattern was measured with a length-measuring scanning electron microscope (SEM, Hitachi, Ltd.). Observed using a manufacturing plant S-9380II), 50 dotted line widths were measured at regular intervals in the range of 2 μm in the longitudinal direction of the space pattern, and 3σ was calculated from the standard deviation. It shows that it is so that it is so favorable that a value is small (in addition, regarding Example 70, it replaced with evaluation of LWR and evaluated the following HR).

[Hall Roughness (HR)]
The above resist pattern was observed using a length measuring scanning electron microscope (SEM, Hitachi, Ltd. S-9380II) and measured by calculating 3σ from the standard deviation of the diameter of the hole pattern. A smaller value indicates better performance.

[Exposure latitude (EL)]
100 nm (1: 1) line and space (however, with respect to Example 70, a hole pattern with a pitch of 200 nm and a hole diameter of 100 nm, and with respect to Example 73 and Comparative Example 6, a resist pattern of 55 nm (1: 1)) Is the optimum exposure amount (in the case of multiple development, it means the exposure amount to form the line-and-space resist pattern after finally undergoing multiple development, and in the case of multiple development, This means the first exposure amount for forming a resist pattern in the space), and the exposure amount width that allows ± 10% of the pattern size when the exposure amount is changed is obtained, and this value is the optimum exposure amount. Divided by and displayed as a percentage. The larger the value, the smaller the change in performance due to the change in exposure amount, and the better the exposure latitude (EL).

[Defocus margin (DOF)]
100 nm (1: 1) line and space (however, with respect to Example 70, a hole pattern with a pitch of 200 nm and a hole diameter of 100 nm, and with respect to Example 73 and Comparative Example 6, a resist pattern of 55 nm (1: 1)) The optimum exposure amount (in the case of multiple development, the exposure amount for forming the line-and-space resist pattern after finally undergoing multiple development, and in the case of multiple development, (This means the first exposure amount for forming the above-mentioned line-and-space resist pattern). When the focus is changed (defocused) with the exposure amount set to the optimum exposure amount, the pattern is obtained. The focus width that allowed ± 10% of the size was determined. The larger the value, the smaller the performance change due to the focus change, and the better the defocus margin (DOF).

  From Tables 7 and 8, it is clear that the negative developing resist composition of the present invention can stably form a high-precision fine pattern excellent in line width roughness, exposure latitude, and defocus margin. .

1 Irradiation light 2 Exposure mask 3 Pattern 4 Wafer

Claims (12)

(A) a resin having an acid-decomposable repeating unit, the polarity being increased by the action of an acid, and the solubility in a negative developer is decreased;
(B) A negative developing resist composition comprising: a photoacid generator that generates an acid represented by the following general formula (I) by irradiation with actinic rays or radiation.

Where
Xf each independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom.
R ₁ and R ₂ each independently represents a hydrogen atom, a fluorine atom, an alkyl group, or a group selected from an alkyl group substituted with at least one fluorine atom, and R ₁ and R ₂ in the case where a plurality of R ₁ and R _{2 are present.} May be the same or different. However, at least one of R ₁ and R ₂ represents a hydrogen atom or an alkyl group.
L represents a divalent linking group, and the divalent linking group is —COO—, —OCO—, —CO—, —O—, —S—, —SO—, an alkylene group, a cycloalkylene group, or Alkenylene group. When there are a plurality of L, they may be the same or different.
A represents a group having a cyclic structure.
x represents an integer of 1 to 20, y represents an integer of 0 to 10, and z represents an integer of 0 to 10. 2. The negative developing resist composition according to claim 1, wherein the acid represented by the general formula (I) is an acid represented by the following general formula (II) or (III).

  3. The negative according to claim 2, wherein the acid represented by the general formula (II) or (III) is an acid represented by the general formula (II) and having two fluorine atoms. Resist composition for mold development.   The negative developing resist composition according to claim 1, wherein A in the acids represented by the general formulas (I) to (III) does not contain a fluorine atom.   The negative developing resist composition according to claim 1, wherein in the general formulas (I), (II), and (III), the cyclic structure in A has 5 or more carbon atoms. object.   The negative developing resist composition according to claim 1, wherein the group having a cyclic structure as A is a cyclic group. (A) forming a film with the negative developing resist composition according to any one of claims 1 to 6;
(A) an exposure process;
(D) a pattern forming method comprising a step of developing using a negative developer.   The negative developer is a developer containing at least one solvent selected from a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent, and an ether solvent. The pattern forming method according to 1. The resin is a resin whose polarity is increased by the action of an acid to increase the solubility in a positive developer,
(C) The pattern forming method according to claim 7 or 8, further comprising a step of developing using a positive developer.   The pattern forming method according to claim 7, wherein the exposure in the exposure step (A) is immersion exposure.   A resist film formed from the negative developing resist composition according to claim 1.   The pattern formed by the pattern formation method in any one of Claims 7-9.

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