JP2008281974A - Pattern forming method, resist composition to be used in the pattern forming method, negative developing solution to be used in the pattern forming method and rinsing solution for negative development to be used in the pattern forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for stably forming a high-accuracy fine pattern to be used in the production process of a semiconductor such as IC, in the production of a circuit substrate of liquid crystal, thermal head and the like or in other photofabrication processes, a resist composition to be used in the method, a developing solution to be used in the method and a rinsing solution to be used in the method. <P>SOLUTION: The pattern forming method includes: (α) coating a resist composition including a resin that includes a specific repeating unit, and, by the action of an acid, increases the polarity and decreases the solubility in a negative developing solution; (β) exposing; and (γ) developing with a negative developing solution. There are also provided the resist composition to be used in the method, the developing solution to be used in the method and the rinsing solution to be used in the method. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pattern forming method used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal or a thermal head, and a lithography process for other photo applications, and a negative development used in the pattern forming method. The present invention relates to a resist composition for multiple development, a resist composition for multiple development used in the pattern formation method, a negative developer used in the pattern formation method, and a negative development rinse used in the pattern formation method. In particular, a pattern forming method, a resist composition used in the pattern forming method, and a pattern forming method 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 The present invention relates to a negative developing solution used in the above and a negative developing rinsing solution used in the pattern forming method.

  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
Where 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 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 is to reduce k ₁ in the above-described resolving power formula, and is positioned as a technique for increasing the resolving power.

Conventionally, pattern formation of an electronic device such as a semiconductor element is performed by changing the pattern size to be formed to
The mask or reticle pattern enlarged by -5 times was reduced and transferred to an object to be exposed such as a wafer by using a reduction projection exposure apparatus.
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 (Japanese Patent Laid-Open No. 2006-156422) and the like.
Recent progress in double exposure technology includes Non-Patent Document 1 (SPIE Proc 5754, 1508 (2005)), Non-Patent Document 2 (SPIE Proc 5377, 1315 (2004)), Non-Patent Document 3 (SPIE Proc 61531K-1 ( 2006)).

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.
That is, a resist composition containing a resin whose polarity is increased by exposure as introduced in Patent Document 2 (Japanese Patent Application Laid-Open No. 2001-109154) is applied to a substrate, exposure, and an exposed portion of the resist film is made alkaline. A resist composition containing a resin whose molecular weight increases by exposure, such as a pattern formation process that dissolves and develops in a developing solution, and a patent document 3 (Japanese Patent Laid-Open No. 2003-76019) is applied to a substrate. If the pattern forming process in which the exposed and unexposed portions of the resist film are dissolved and developed with an alkaline developer is applied to the double exposure process, sufficient resolution performance cannot be obtained.

At present, as a developing solution for g-line, i-line, KrF, ArF, EB, EUV lithography, an aqueous alkaline developer of 2.38% by mass TMAH (tetramethylammonium hydroxide) is widely used.
As a developer other than the above, for example, Patent Document 4 (Japanese Patent Laid-Open No. 2001-215731) discloses an exposed portion of a resist material containing a copolymer of a styrene monomer and an acrylic monomer. A developer containing an aliphatic linear ether solvent or aromatic ether solvent for dissolving and developing and a ketone solvent having 5 or more carbon atoms is described. Patent Document 5 (Japanese Patent Application Laid-Open No. 2006-227174) discloses an acetic acid group or a ketone group for dissolving and developing an exposed portion of a resist material that has a polymer chain that is cut and reduced in molecular weight upon irradiation with radiation. And a developer having at least two ether groups and phenyl groups and having a molecular weight of 150 or more. Further, Patent Document 6 (Japanese Patent Application Laid-Open No. 6-194847) discloses an unexposed resist material mainly composed of a photosensitive polyhydroxyether resin obtained by a reaction between a polyhydroxyether resin and glycidyl (meth) acrylate. Described is a developer characterized by using as a developer a mixed solvent containing 50% by mass or more of an aromatic compound having 6 to 12 carbon atoms or an aromatic compound having 6 to 12 carbon atoms for developing a portion. Yes.
However, in the combination of the resist composition and the developer described above, a specific resist composition is combined with a developer containing a high polarity alkaline developer or a low polarity 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 an optical aerial image (light intensity distribution) is selectively dissolved and dissolved. Only the material to be removed and patterned is 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.

A double development technique as a double patterning technique for increasing the resolving power is described in Patent Document 7 (Japanese Patent Laid-Open No. 2000-199953). 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 or more of the irradiation light 1 is dissolved using an alkaline aqueous solution as a positive developer, and a region where the exposure amount E1 or less is negative with a specific organic solvent. It is dissolved as a developer. 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, in the above example, the acid-decomposable group of the resin of the resist composition is tert-
Since a butyl group is used, it has been impossible to express a change in the polarity of the resin sufficient to cause a difference in solubility characteristics by a chemical amplification reaction accompanying exposure.
Furthermore, since a resin containing a styrene skeleton is used as the resin of the resist composition, the polarity of the low-exposed region of the resist film is high, and therefore the development speed when developing with a negative developer is slow. There was a problem that the developability at the time of using a negative developer was deteriorated.

JP 2006-156422 A Japanese Patent Laid-Open No. 2001-109154 JP 2003-76019 A JP 2001-215731 A JP 2006-227174 A Japanese Patent Laid-Open No. 6-194847 Japanese Unexamined Patent Publication No. 2000-199953 SPIE Proc 5754,1508 (2005) SPIE Proc 5377,1315 (2004) SPIE Proc 61531K-1 (2006)

  The present invention solves the above-described problems, stably forms a high-precision fine pattern, and manufactures a highly integrated and high-precision electronic device, so that line edge roughness is reduced and pattern dimensional uniformity is achieved. It is an object of the present invention to provide a method for forming a pattern with an increased sag.

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

(1) (a) A resist composition comprising a resin having a repeating unit represented by the following general formula (NGH-1), which increases in polarity by the action of an acid and decreases in solubility in a negative developer. Applying step,
A pattern forming method comprising: (a) an exposure step; and (d) a step of developing using a negative developer.

In the general formula (NGH-1),
R _NGH1 represents a hydrogen atom or an alkyl group.
R _{NGH2 to} R _NGH4 each independently represent a hydrogen atom or a hydroxyl group. However, at least one of R _{NGH2 to} R _NGH4 represents a hydroxyl group.

  (2) The step of developing using a negative developer is a step of using a negative developer containing an organic solvent and having a vapor pressure at 20 ° C. of 5 kPa or less (1) The pattern forming method according to 1.

(3) The pattern forming method as described in (1) or (2), further comprising (f) a step of washing with a negative developing rinsing solution containing an organic solvent.

  (4) The step of washing with a negative developing rinse containing an organic solvent, using a negative developing rinse containing an organic solvent and having a vapor pressure at 20 ° C. of 0.1 kPa or more. (4) The pattern forming method as described in (3) above.

(5) The pattern forming method as described in any one of (1) to (4), further comprising (c) a step of developing using a positive developer.

  (6) (A) a resin having a repeating unit represented by the following general formula (NGH-1), having increased polarity by the action of an acid and having reduced solubility in a negative developer, (B) active light or A negative developing resist composition comprising a compound that generates an acid upon irradiation with radiation and (C) a solvent.

In the general formula (NGH-1),
R _NGH1 represents a hydrogen atom or an alkyl group.
R _{NGH2 to} R _NGH4 each independently represent a hydrogen atom or a hydroxyl group. However, at least one of R _{NGH2 to} R _NGH4 represents a hydroxyl group.

  (7) (A) It has a repeating unit represented by the following general formula (NGH-1), the polarity is increased by the action of an acid, the solubility in a negative developer is decreased, and the solubility in a positive developer is increased. A resist composition for multiple development, comprising an increasing resin, (B) a compound that generates an acid upon irradiation with actinic rays or radiation, and (C) a solvent.

In the general formula (NGH-1),
R _NGH1 represents a hydrogen atom or an alkyl group.
R _{NGH2 to} R _NGH4 each independently represent a hydrogen atom or a hydroxyl group. However, at least one of R _{NGH2 to} R _NGH4 represents a hydroxyl group.

  (8) The negative developer used in the pattern forming method according to (1), which contains an organic solvent and has a vapor pressure at 20 ° C. of 5 kPa or less.

  (9) The negative developing rinse solution used for the pattern forming method according to (3), which contains an organic solvent and has a vapor pressure at 20 ° C. of 0.1 kPa or more.

  INDUSTRIAL APPLICABILITY According to the present invention, a method for forming a pattern with reduced line edge roughness and increased pattern dimensional uniformity, a negative developing resist composition used in the method, and a multiple developing resist composition used in the method The negative developer used in the method and the negative developer rinse used in the method can be provided.

Hereinafter, the best mode 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 what does not have a substituent and what has 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).

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 in which the development process using the positive developer and the development process using the negative developer are combined. 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 indicates both a negative developing resist composition and a multiple 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. 2, a developer (negative developer) that selectively dissolves and removes an exposed portion having a predetermined threshold value (b) or less, and the following general formula (NGH) -1), a new pattern which is combined with a negative developing resist composition containing a resin having a repeating unit represented by formula (1) and having an increased polarity by the action of an acid and a reduced solubility in a negative developing solution. The formation method is presented.

In the general formula (NGH-1),
R _NGH1 represents a hydrogen atom or an alkyl group.
R _{NGH2 to} R _NGH4 each independently represent a hydrogen atom or a hydroxyl group. However, at least one of R _{NGH2 to} R _NGH4 represents a hydroxyl group.

In the present invention, as a technique for increasing the resolving power, more preferably, a developer (positive developer) that selectively dissolves and removes an exposed portion having a predetermined threshold value (a) or higher, and a predetermined threshold value (b) or lower. A developer (negative developer) that selectively dissolves and removes the exposed area and a repeating unit represented by the general formula (NGH-1), the polarity is increased by the action of an acid, and a negative developer. A new pattern forming method is proposed, which is combined with a resist composition for multi-development containing a resin having a reduced solubility in a positive developer and an increased solubility in a positive developer.
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. Further, in the method of the present invention, it is not necessary to divide the design of the exposure mask.

  As the resist composition for multiple development in the case where the above two or more developments are simultaneously performed, a negative developing resist composition can be used as it is.

A pattern forming process necessary for carrying out the present invention includes the following steps.
(A) The process of apply | coating the resist composition containing resin which has a repeating unit represented by the following general formula (NGH-1), increases polarity by the effect | action of an acid, and the solubility with respect to a negative developing solution decreases. ,
(A) an exposure step and (d) a step of developing using a negative developer.

In the general formula (NGH-1),
R _NGH1 represents a hydrogen atom or an alkyl group.
R _{NGH2 to} R _NGH4 each independently represent a hydrogen atom or a hydroxyl group. However, at least one of R _{NGH2 to} R _NGH4 represents a hydroxyl group.

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

  The pattern formation method of the present invention preferably further includes (c) a step of developing using a positive developer.

  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.

  In practicing the present invention, a resist composition containing a resin having a repeating unit represented by the following general formula (NGH-1), which increases in polarity by the action of an acid and decreases in solubility in a negative developer. Product, negative developer (preferably an organic developer) and preferably a negative developer rinse solution containing an organic solvent.

In the general formula (NGH-1),
R _NGH1 represents a hydrogen atom or an alkyl group.
R _{NGH2 to} R _NGH4 each independently represent a hydrogen atom or a hydroxyl group. However, at least one of R _{NGH2 to} R _NGH4 represents a hydroxyl group.

  In order to carry out the present invention, it is further preferable to use a positive developer (preferably an alkali developer).

  The order of development in the pattern forming process using two types of developer, a positive developer and a negative developer, is not particularly limited. After the first exposure, the positive developer or the negative developer is used. It is preferable to perform development, and then to perform negative-type or positive-type development using a developer different from the first development. Furthermore, after negative development, it is preferable to wash with a negative development 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.

The resist composition of the present invention is “a resin composition containing a resin having a repeating unit represented by the general formula (NGH-1), whose polarity is increased by the action of an acid and whose solubility in a negative developer is decreased. Things ".
The resin contained in the resist composition of the present invention not only decreases the solubility in a negative developer by increasing the polarity by the action of an acid, but also increases the solubility in an alkaline developer at the same time.
For this reason, the resist composition of the present invention acts as a negative type for a negative developer, and at the same time acts as a positive type for a positive developer.
In the present invention, an organic developer containing an organic solvent can be used as the negative developer, and an alkaline developer (aqueous) can be used as the positive developer.

In the present invention, it is important to control the “threshold value” 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 solubilized in the positive developer and the maximum exposure amount insolubilized in the negative developer so that a desired line width can be obtained are 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 the positive developer and the maximum exposure amount insolubilized in the 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 In contrast, the remaining film rate is 100
The exposure amount that becomes% 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 the first exposure, development is performed using a positive developer or a negative developer, and then, after the second exposure, with a developer different from the first development, Perform 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 is determined based on the sum of the first and second exposure history, but the second exposure is the first exposure. 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.
The exposure amount (Eo1 [mJ / cm ² ]) in the first exposure process is 5 [mJ / cm ² ] or more from the exposure amount (Eo2 [mJ / cm ² ]) in the ^second exposure process. Smaller is desirable. This is 1
The influence of the history of the second exposure on the process of pattern formation by the second exposure can be reduced.

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.
On the substrate, a film is formed of a resist composition containing a resin that has a repeating unit represented by the general formula (NGH-1), increases in polarity by the action of an acid, and decreases in solubility in a negative developer. After that, exposure is performed through a photomask having a desired pattern size under a desired illumination condition. At this time, exposure is performed while swinging the focus of exposure (focus) by 0.05 [μm] and the exposure amount by 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 an exposure amount A [mJ / cm ² ] and a focus position for forming a desired line width are determined. Next, the intensity distribution of the optical image when the previous photomask is irradiated at a specific exposure amount A [mJ / cm ² ] and a specific focus position is calculated. The calculation can be performed using simulation software (Prolith ver.9.2.0.15 manufactured by KLA). Details of the calculation method are described in Inside PROLITH (Chris. A. Mack, FINLE Technologies, Inc., Cahpter2 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 1/2 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.
On the substrate, a film is formed of a resist composition containing a resin that has a repeating unit represented by the general formula (NGH-1), increases in polarity by the action of an acid, and decreases in solubility in a negative developer. After that, exposure is performed through a photomask having a desired pattern size under a desired illumination condition. At this time, exposure is performed while swinging the focus of exposure (focus) by 0.05 [μm] and the exposure amount by 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 an exposure amount A [mJ / cm ² ] and a focus position for forming a desired line width are determined. Next, the intensity distribution of the optical image when the previous photomask is irradiated at a specific exposure amount A [mJ / cm ² ] and a 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 the threshold value (b). And

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 (b) is preferably 0.1 to 100 [mJ / cm ² ],
More preferably, it is 0.5-50 [mJ / cm < ² >], More preferably, it is 1-30 [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 more preferably 1 to 30 [mJ / cm ² ].

  In the present invention, the film formed on the substrate has a repeating unit represented by the following general formula (NGH-1), the polarity is increased by the action of an acid, and the solubility in a negative developer is decreased. It is a film formed by applying a resist composition containing a resin.

In the general formula (NGH-1),
R _NGH1 represents a hydrogen atom or an alkyl group.
R _{NGH2 to} R _NGH4 each independently represent a hydrogen atom or a hydroxyl group. However, at least one of R _{NGH2 to} R _NGH4 represents a hydroxyl group.

  Hereinafter, the resist composition that can be used in the present invention will be described.

(A) Resin having a repeating unit represented by the general formula (NGH-1), having increased polarity by the action of an acid, and having reduced solubility in a negative developer, The resist composition of the present invention has the following general formula It contains a resin (hereinafter also referred to as “resin (A)”) that has a repeating unit represented by (NGH-1), increases in polarity by the action of an acid, and decreases in solubility in a negative developer.

In the general formula (NGH-1),
R _NGH1 represents a hydrogen atom or an alkyl group.
R _{NGH2 to} R _NGH4 each independently represent a hydrogen atom or a hydroxyl group. However, at least one of R _{NGH2 to} R _NGH4 represents a hydroxyl group.

In general formula (NGH-1), the alkyl group of R _NGH1 is preferably an alkyl group having 1 to 4 carbon atoms, and may be substituted with a fluorine atom, a hydroxyl group, or the like.
R _NGH1 is preferably _a hydrogen atom, a methyl group or an ethyl group. R _NGH1 is more preferably _a methyl group.
Of _{RNGH2 to RNGH4} , one or two are preferably a hydroxyl group and the rest are hydrogen atoms.

  The content of the repeating unit represented by the general formula (NGH-1) is preferably 1 to 15 mol%, more preferably 5 to 15 mol%. By setting the content to 1 to 15 mol%, the affinity for the negative developer and the positive developer is improved.

  Further, the resin (A) has a repeating unit represented by the general formula (NGH-1), whereby the substrate adhesion is improved.

  Specific examples of the repeating unit having a structure represented by the general formula (NGH-1) are shown below, but the present invention is not limited thereto.

Resin (A) is a resin whose polarity increases by the action of an acid.
Resin (A) is a group that decomposes by the action of an acid on the main chain or side chain of the resin, or both of the main chain and side chain, to generate an alkali-soluble group (hereinafter also referred to as “acid-decomposable group”). It is preferable that it is resin which polarity increases by the effect | action of an acid by having.
Resin (A) is increased in polarity by the action of acid, so that the solubility in negative developer is reduced by the action of acid.
Further, the resin (A) is increased in polarity by the action of an acid, so that the solubility in a positive developer is increased by the action of an acid.

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, carboxylic acid groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, (alkylsulfonyl) (alkylcarbonyl) Imido 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 A group having
Preferred alkali-soluble groups include carboxylic acid groups, fluorinated alcohol groups (preferably hexafluoroisopropanol), and sulfonic acid groups.
Examples of the group leaving with an acid include -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 and} 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.

Resin (A) is a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure, increasing polarity by the action of an acid, decreasing solubility in negative developer, and increasing solubility in positive developer. (Hereinafter also referred to as “alicyclic hydrocarbon-based acid-decomposable resin”) is more preferable.
The reason is that by having a monocyclic or polycyclic alicyclic hydrocarbon structure, the polarity of the resin changes greatly before and after irradiation with actinic rays or radiation, and a negative developer (preferably an organic solvent) and This is because the dissolution contrast is improved when developing with a positive developer (preferably an alkali developer).
Furthermore, a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure generally has high hydrophobicity, and a negative developing solution (preferably an organic solvent) is used to develop a region of a resist film where the light irradiation intensity is low. The developing speed is high, and the developability when using a negative developer is improved.

  The resist composition of the present invention containing an alicyclic hydrocarbon-based acid-decomposable resin can be suitably used when irradiating ArF excimer laser light.

As the alicyclic hydrocarbon-based acid-decomposable resin, 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-
A resin containing at least one selected from the group of repeating units represented by AB) is preferred.

In the general formulas (pI) to (pV),
R ₁₁ represents an alkyl group.
Z represents an atomic group necessary for forming a cycloalkyl group together with a carbon atom.
R _{12 to} R ₁₄ each independently represents an alkyl group or a cycloalkyl group. However, at least one of R _{12 to} R ₁₄ represents a cycloalkyl group.
R ₁₅ and R ₁₆ each independently represents an alkyl group or a cycloalkyl group. However, at least one of R ₁₅ and R ₁₆ represents a cycloalkyl group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group. However, at least one of R _{17 to} R ₂₁ represents a cycloalkyl group. Moreover, any of R ₁₉ and R ₂₁ represents an alkyl group or a cycloalkyl group.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, an alkyl group 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 general 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 , a group that decomposes by the action of an acid, —C (═O) —XA′—R. ₁₇ ′ represents an alkyl group or a cycloalkyl group. At least two 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), the alkyl group in R _{11 to} R ₂₅ is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, Examples include n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group and the like.

The cycloalkyl group represented by R _{12 to} R ₂₅ or the cycloalkyl group formed by Z and the carbon atom may be monocyclic or polycyclic. Specifically, monocyclo, bicyclo having 5 or more carbon atoms,
Examples thereof include a group having a tricyclo or tetracyclo structure. 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.

  These alkyl groups and cycloalkyl groups may have a further substituent. As further substituents for 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 (2 to 2 carbon atoms). 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 carboxylic acid group, a sulfonic acid group, a phenol group, or a thiol group is substituted with a structure represented by the general formulas (pI) to (pV), preferably a carboxylic acid Group, a hydrogen atom of a sulfonic acid group is substituted with a structure represented by 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, R represents a hydrogen atom, a halogen atom or an alkyl group (preferably 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 general 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 shown by general formula (pA) 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 for R ₁₁ ′ and R ₁₂ ′ include linear or branched alkyl groups 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 the resin, and in particular, a bridged alicyclic ring An atomic group for forming a bridged alicyclic structure forming a repeating unit of the formula hydrocarbon is preferred.

Examples of the skeleton of the alicyclic hydrocarbon formed include the same alicyclic hydrocarbon groups as 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 according to the present invention, the acid-decomposable group has a repeating unit having a partial structure containing the alicyclic hydrocarbon represented by the general formula (pI) to the general formula (pV). In addition, it can be contained in at least one repeating unit among the repeating unit represented by formula (II-AB) and the repeating unit of the copolymerization component described later. The acid-decomposable group 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 (II-AB2) are atomic groups or bridged formulas for forming an alicyclic structure in the general formula (II-AB). It can also be a substituent of the atomic group Z for forming an 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 of the present invention preferably has a lactone group. As the lactone group, any group can be used as long as it contains a lactone structure, but preferably a group containing a 5- to 7-membered ring lactone structure, and a bicyclo structure in the 5- to 7-membered ring lactone structure, Those in which other ring structures are condensed to form a spiro 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 (LC1-16). Further, a group having a lactone structure may be directly bonded to the main chain. Preferred lactone structures are groups represented by general formulas (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), (LC1-14), By using a specific lactone structure, line edge roughness and development defects are improved.

The lactone structure moiety may or may not have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include an alkyl group (preferably having 1 to 8 carbon atoms), a cycloalkyl group (preferably having 4 to 7 carbon atoms), an alkoxy group (preferably having 1 to 8 carbon atoms), and an alkoxycarbonyl group. (Preferably having 1 to 8 carbon atoms), carboxyl group, halogen atom, hydroxyl group, cyano group, acid-decomposable group and the like. n2 represents an integer of 0 to 4. When n2 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 (LC1-16), R _{13 in the} general formula (II-AB1) or (II-AB2) may be used. Wherein at least one of 'to R ₁₆ ' has a group represented by the general formulas (LC1-1) to (LC1-16) (for example, R _{5 of} -COOR ₅ is represented by the general formulas (LC1-1) to (LC1) -16) 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 (preferably having 1 to 4 carbon atoms).
Preferred substituents that the alkyl group represented by 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 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 (LC1-16).

  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.

The alicyclic hydrocarbon-based acid-decomposable resin of the present invention is a repeating unit containing an organic group having a polar group other than the hydroxyl group-containing alicyclic hydrocarbon group in the repeating unit represented by the general formula (NGH-1). In particular, it may have a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group. Thereby, the substrate adhesion is further improved. 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. As the polar group, a carboxyl group and a cyano group are preferable.
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 carboxyl group or a cyano group. However, at least one of R _{2c to} R _4c represents a carboxyl group or a cyano group. Preferably, one or two of R _{2c to} R _4c are cyano groups and the rest are hydrogen atoms.
In general formula (VIIa), it is more preferable that two of R _{2c to} R _4c are cyano groups and the rest are hydrogen atoms.

As the repeating unit having a group represented by general formulas (VIIa) to (VIId), at least one of R ₁₃ ′ to R ₁₆ ′ in general formula (II-AB1) or (II-AB2) is generally Those having groups represented by 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 the general formulas (AIIa) to (AIId),
R _1c represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R _2c to R _4c is a general formula (VIIa) ~ same meanings as in R _2c to R _4c in (VIIc).

  Although the specific example of the repeating unit which has a structure represented by general formula (AIIa)-(AIId) is given to the following, this invention is not limited to these.

  The alicyclic hydrocarbon-based acid-decomposable resin of the present invention 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 of the present invention preferably has a repeating unit having an alkali-soluble group, and more preferably has a repeating unit having a carboxyl group. By containing 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 at the time of 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 of the present invention may further have a repeating unit having 1 to 3 groups represented by the general formula (F1). This improves line edge roughness performance.

In general formula (F1),
R _{50 to} R ₅₅ each independently represents 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, alkyl group, cycloalkyl group, acyl group, alkylcarbonyl group, alkoxycarbonyl group, alkoxycarbonylmethyl group, alkoxymethyl group, 1-alkoxyethyl 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, etc., 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 (F2).

In general formula (F2),
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 of the present invention may further contain a repeating unit having an alicyclic hydrocarbon structure and not exhibiting acid decomposability. This can reduce the elution of low molecular components from the resist film to the immersion liquid during immersion exposure. Examples of such a repeating unit include a repeating unit of 1-adamantyl (meth) acrylate, tricyclodecanyl (meth) acrylate, and cyclohexyl (meth) acrylate.

  In addition to the above repeating structural units, the alicyclic hydrocarbon-based acid-decomposable resin of the present invention has a dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolving power that is a general necessary characteristic of a resist. Various repeating structural units can be contained for the purpose of adjusting heat resistance, sensitivity, and the like.

  Examples of such repeating structural units include, but are not limited to, repeating structural 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's dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolution that is a 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 of the present invention include the following.
(1) Having a repeating unit having a partial structure including a repeating unit represented by the general formula (NGH-1) and an alicyclic hydrocarbon represented by the general formulas (pI) to (pV) (side chain type) ).
Preferably, those having a repeating unit represented by formula (NGH-1) and a (meth) acrylate repeating unit having a structure of formulas (pI) to (pV).
(2) Those having a repeating unit represented by the general formula (NGH-1) and 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) A repeating unit represented by the general formula (NGH-1), a repeating unit represented by the general formula (II-AB), a maleic anhydride derivative and a (meth) acrylate structure (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 lactone ring is preferably 10 to 70 mol%, more preferably 20 to 60 mol%, still more preferably 25 to 40 in all repeating structural units. Mol%.
In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit represented by the general formula (NGH-1) is preferably 1 to 15 mol%, more preferably 5 to 15 mol%.
In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having an organic group having a polar group other than the polar group contained in the general formula (NGH-1) is 1 to 30 mol% in all repeating structural units. Is more preferable, more preferably 1 to 20 mol%, still more preferably 5 to 15 mol%.

  In addition, the content of the repeating structural unit based on the monomer of the further copolymer component in the resin can be appropriately set according to the performance of the desired resist. Generally, the general formula (NGH- 1), a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by general formulas (pI) to (pV), and a repeating unit represented by general formula (II-AB) 99 mol% or less is preferable, more preferably 90 mol% or less, and still more preferably 80 mol% or less with respect to the total number of moles.

  When the 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 used in the present invention 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 repeating unit represented by the general formula (NGH-1), a (meth) acrylate-based repeating unit having a lactone ring, and an acid-decomposable group (meth). A copolymer having an acrylate repeating unit is preferred.

  Preferably, 1 to 15 mol% of the repeating unit represented by the general formula (NGH-1) and the repeating unit 20 to 20 having a partial structure containing an alicyclic hydrocarbon represented by the general formulas (pI) to (pV) The copolymer is a copolymer having 50 mol%, 20 to 50 mol% of repeating units having a lactone structure, or a 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- 6) 50 to 50 mol% of a repeating unit having a lactone group represented by formula (6), and a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group represented by the following general formulas (ARH-1) to (ARH-2) A ternary copolymer containing 1 to 15 mol% of units, or a repeating unit having a structure represented by a carboxyl group or general formula (F1), an alicyclic hydrocarbon structure, and not exhibiting acid decomposability It 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.)

  The alicyclic hydrocarbon-based acid-decomposable resin used in the present invention 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 the polymerization is performed by heating, 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, 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 the reaction is 5 to 50% by mass, preferably 10 to 30% by mass. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 60-100 ° 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) according to the present invention is preferably 1,000 to 200,000, more preferably 1,000 to 20,000, and most preferably 1, as a polystyrene conversion value by GPC method. 000 to 15,000. The weight average molecular weight is 1,000
By setting it to 0-200,000, it is possible to prevent deterioration of heat resistance and dry etching resistance, and it is possible to prevent developability and deterioration of film forming property due to increased viscosity.
Another most preferable form of the weight average molecular weight of the resin (A) according to the present invention is 3,000 to 9,500 in terms of polystyrene by GPC method. By setting the weight average molecular weight to 3,000 to 9,500, resist residues (hereinafter also referred to as “scum”) are particularly suppressed, and a better pattern can be formed.
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.

  The alicyclic hydrocarbon-based acid-decomposable resin of the present invention preferably has no fluorine atom or silicon atom from the viewpoint of compatibility with the resin (D).

(B) Compound that generates acid upon irradiation with actinic ray or radiation The resist composition of the present invention is a compound that generates acid upon irradiation with actinic ray or radiation (also referred to as “photoacid generator” or “(B) component”). ).
Examples of such photoacid generators include photoinitiators for photocationic polymerization, photoinitiators for photoradical polymerization, photodecolorants for dyes, photochromic agents, actinic rays used in microresists, etc. Known compounds that generate an acid upon irradiation with radiation and mixtures thereof can be appropriately selected and used.

  Examples thereof include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates.

  Further, a group that generates an acid upon irradiation with these actinic rays or radiation, or a compound in which a compound is introduced into the main chain or side chain of the polymer, for example, US Pat. No. 3,849,137, German Patent No. 3914407. JP, 63-26653, JP, 55-164824, JP, 62-69263, JP, 63-146038, JP, 63-163452, JP, 62-153853, The compounds described in JP-A 63-146029 can be used.

Furthermore, compounds capable of generating an acid by light described in US Pat. No. 3,779,778, European Patent 126,712 and the like can also be used.

  Among the compounds that decompose upon irradiation with actinic rays or radiation to generate an acid, compounds represented by the following general formulas (ZI), (ZII), and (ZIII) can be exemplified.

In general formula (ZI),
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents a non-nucleophilic anion, preferably sulfonate anion, carboxylate anion, bis (alkylsulfonyl) amide anion, tris (alkylsulfonyl) methide anion, BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ^{− and the} like. Preferably, it is an organic anion containing a carbon atom.

  Preferable organic anions include organic anions represented by the following formula.

Where
Rc ₁ represents an organic group.
Examples of the organic group in Rc ₁ include those having 1 to 30 carbon atoms, and preferably an alkyl group, an aryl group, or a plurality thereof, which may be substituted, is a single bond, —O—, —CO ₂ —.
, —S—, —SO ₃ —, —SO ₂ N (Rd ₁ ) — and the like. Rd ₁ represents a hydrogen atom or an alkyl group.
Rc ₃ , Rc ₄ and Rc ₅ each independently represents an organic group. Preferred examples of the organic group for Rc ₃ , Rc ₄ , and Rc ₅ include the same organic groups as those for Rc ₁ , and particularly preferred is a perfluoroalkyl group having 1 to 4 carbon atoms.
Rc ₃ and Rc ₄ may combine to form a ring. Examples of the group formed by combining Rc ₃ and Rc ₄ include an alkylene group and an arylene group. Preferably, it is a C2-C4 perfluoroalkylene group.
Rc ₁ and particularly preferably as, rc ₃ organic groups to Rc ₅ is at least one position is an alkyl group substituted with a fluorine atom or a fluoroalkyl group, a phenyl group substituted with a fluorine atom or a fluoroalkyl group. By having a fluorine atom or a fluoroalkyl group, the acidity of the acid generated by light irradiation is increased and the sensitivity is improved. Further, when Rc ₃ and Rc ₄ are combined to form a ring, the acidity of the acid generated by light irradiation is increased, and the sensitivity is improved.

The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1 to 30, preferably 1
~ 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. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).
Specific examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include a compound (ZI-1) described later.
), (ZI-2) and (ZI-3).

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

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

The compound (ZI-1) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (ZI), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.
In the arylsulfonium compound, all of R _{201 to} R ₂₀₃ may be an aryl group, or R ₂₀₁
Some of to R ₂₀₃ is an aryl group with the remaining being 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 an aryl group such as a phenyl group or a naphthyl group, or a heteroaryl group such as an indole residue or a pyrrole residue, and more preferably a phenyl group or an indole 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 that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, sec- Examples thereof include a butyl group and a t-butyl group.
The cycloalkyl group that the arylsulfonium compound has as necessary is preferably a cycloalkyl group having 3 to 15 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.
Aryl group, alkyl group of R ₂₀₁ to R _203, cycloalkyl group, 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, and particularly preferable. Is 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 the 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 the case where R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group not containing an aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.
The organic group having no 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, branched, cyclic 2-oxoalkyl group, or an alkoxycarbonylmethyl group, particularly preferably Is a linear, branched 2-oxoalkyl group.

The alkyl group as R ₂₀₁ to R ₂₀₃ may be linear, it may be either branched, preferably a straight-chain or branched alkyl group (e.g., methyl group having 1 to 10 carbon atoms, an ethyl group, a propyl Group, butyl group, pentyl group). The alkyl group as R ₂₀₁ to R ₂₀₃ is a straight-chain or branched 2-oxoalkyl group is preferably an alkoxycarbonyl methyl group.
The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably, and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl). The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably a cyclic 2-oxoalkyl group.
Linear as R ₂₀₁ to R _203, branched or cyclic 2-oxoalkyl group may preferably be a group having a 2-position> C = O in the above-described alkyl or cycloalkyl group.
The alkoxy group in the alkoxycarbonylmethyl group as R ₂₀₁ to R _203, preferably may be mentioned alkoxy groups having 1 to 5 carbon atoms (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a 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 each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, or a halogen atom.
R _6c and R _7c each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
Rx and Ry each independently represents an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group.
Any two or more of R _1c to R _7c, and R _x and R _y may be bonded to each other to form a ring structure, the ring structure may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond May be included. Examples of the group formed by combining any two or more of R _{1c to} R _7c and R _x and R _y include a butylene group and a pentylene group.
X ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as X ^{− in} formula (ZI).

The alkyl group as R _{1c to} R _7c may be either linear or branched, for example, a linear or branched alkyl group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms. Or a linear or branched alkyl group (for example, a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, or a linear or branched pentyl group).
The cycloalkyl group as R _{1c to} R _7c is preferably a cycloalkyl group having 3 to 8 carbon atoms (for example, a cyclopentyl group or a cyclohexyl group).
The alkoxy group as R _{1c to} R _{5c may} be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms. (For example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), C3-C8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) ).
Preferably, any one of R _{1c to} R _5c is a linear or branched alkyl group, a cycloalkyl group, or a linear, branched or cyclic alkoxy group, and more preferably the sum of the carbon number of R _{1c to} R _5c is 2 ~ 15. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

_Examples of the alkyl group as R _x and R _y include the same alkyl groups as R _{1c to} R _7c . The alkyl group as R _x and R _y is preferably a linear or branched 2-oxoalkyl group or an alkoxycarbonylmethyl group.
The cycloalkyl group as R _x and R _y may be the same as the cycloalkyl group as R _1c to R _7c. The cycloalkyl group as R _x and R _y is preferably a cyclic 2-oxoalkyl group.
Examples of the linear, branched, or cyclic 2-oxoalkyl group include a group having> C═O at the 2-position of the alkyl group or cycloalkyl group as R _{1c to} R _7c .
Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as R _{1c to} R _5c .
R _x and R _y are preferably an alkyl group having 4 or more carbon atoms, more preferably 6 or more, and still more preferably 8 or more.

In general formulas (ZII) and (ZIII),
R ₂₀₄ to R ₂₀₇ each independently represents an aryl group, an alkyl group or a cycloalkyl group.
Phenyl group and a naphthyl group are preferred as the aryl group of R ₂₀₄ to R _207, more preferably a phenyl group.
The alkyl group as R ₂₀₄ to R ₂₀₇ may be linear, it may be either branched, preferably a straight-chain or branched alkyl group (e.g., methyl group having 1 to 10 carbon atoms, an ethyl group, a propyl Group, butyl group, pentyl group).
The cycloalkyl group as R ₂₀₄ to R ₂₀₇ is preferably, and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl).
R ₂₀₄ to R ₂₀₇ may have a substituent. The R ₂₀₄ to R ₂₀₇ are substituents which may have, 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 (e.g., 6 carbon atoms 15), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.
X ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as X ^{− in} formula (ZI).

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, compounds represented by the following general formulas (ZIV), (ZV), and (ZVI) can be further exemplified.

In the general formulas (ZIV) to (ZVI),
Ar ₃ and Ar ₄ each independently represents an aryl group.
R ₂₂₆ represents an alkyl group or an aryl group.
R ₂₂₇ and R ₂₂₈ each independently represents an alkyl group, an aryl group, or an electron-withdrawing group. R ₂₂₇ is preferably an aryl group. R ₂₂₈ is preferably an electron-withdrawing group, more preferably a cyano group or a fluoroalkyl group.
A represents an alkylene group, an alkenylene group or an arylene group.

  As the compound that generates an acid upon irradiation with actinic rays or radiation, compounds represented by general formulas (ZI) to (ZIII) are preferable.

  The compound (B) is preferably a compound that generates an aliphatic sulfonic acid having a fluorine atom or a benzenesulfonic acid having a fluorine atom upon irradiation with actinic rays or radiation.

  The compound (B) preferably has a triphenylsulfonium structure.

  The compound (B) is preferably a triphenylsulfonium salt compound having an alkyl group or a cycloalkyl group not substituted with fluorine in the cation moiety.

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, examples of particularly preferable compounds are listed below.

A photo-acid generator can be used individually by 1 type or in combination of 2 or more types. When two or more types are used in combination, it is preferable to combine two types of compounds that generate two types of organic acids that differ in the total number of atoms excluding hydrogen atoms by two or more.
The content of the photoacid generator is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and further preferably 1 to 7% by mass, based on the total solid content of the resist composition. .

(C) Solvent 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, lactate alkyl ester, and alkoxypropion. Organic solvents such as alkyl acid, cyclic lactone (preferably having 4 to 10 carbon atoms), monoketone compound (preferably having 4 to 10 carbon atoms) which may contain a ring, alkylene carbonate, alkyl alkoxyacetate, alkyl pyruvate, etc. be able to.

Examples of the alkylene glycol monoalkyl ether carboxylate include propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol monomethyl ether propionate, propylene glycol monoethyl Preferred examples include ether propionate, ethylene glycol monomethyl ether acetate, and ethylene glycol monoethyl ether acetate.
Preferred examples of the alkylene glycol monoalkyl ether include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether.

Preferred examples of the alkyl lactate include methyl lactate, ethyl lactate, propyl lactate and butyl lactate.
Preferable examples of the alkyl alkoxypropionate include ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, methyl 3-ethoxypropionate, and ethyl 3-methoxypropionate.

  Examples of the cyclic lactone include β-propiolactone, β-butyrolactone, γ-butyrolactone, α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, γ-valerolactone, γ-caprolactone, and γ-octano. Preferred are iclactone and α-hydroxy-γ-butyrolactone.

Examples of the monoketone compound which may contain a ring include 2-butanone, 3-methylbutanone, pinacolone, 2-pentanone, 3-pentanone, 3-methyl-2-pentanone, 4-methyl-2-pentanone, 2 -Methyl-3-pentanone, 4,4-dimethyl-2-pentanone, 2,4-dimethyl-3-pentanone, 2,2,4,4-tetramethyl-3-pentanone, 2-hexanone, 3-hexanone, 5-methyl-3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-methyl-3-heptanone, 5-methyl-3-heptanone, 2,6-dimethyl-4-heptanone, 2-octanone, 3-octanone, 2-nonanone, 3-nonanone, 5-nonanone, 2-decanone, 3-decanone, 4-decanone, 5-hexen-2-one 3-penten-2-one, cyclopentanone, 2-methylcyclopentanone, 3-methylcyclopentanone, 2,2-dimethylcyclopentanone, 2,4,4-trimethylcyclopentanone, cyclohexanone, 3- Methylcyclohexanone, 4-methylcyclohexanone, 4-ethylcyclohexanone, 2,2-dimethylcyclohexanone, 2,6-dimethylcyclohexanone, 2,2,6-trimethylcyclohexanone, cycloheptanone, 2-methylcycloheptanone, 3-methyl Preferred is cycloheptanone.

Preferred examples of the alkylene carbonate include propylene carbonate, vinylene carbonate, ethylene carbonate, and butylene carbonate.
Examples of the alkyl alkoxyacetate include 2-methoxyethyl acetate, 2-ethoxyethyl acetate, 2- (2-ethoxyethoxy) ethyl acetate, 3-methoxy-3-methylbutyl acetate, and 1-methoxy-acetate. 2-propyl is preferred.
Preferred examples of the alkyl pyruvate include methyl pyruvate, ethyl pyruvate, and propyl pyruvate.
As a solvent which can be preferably used, a solvent having a boiling point of 130 ° C. or higher under normal temperature and normal pressure can be mentioned. Specifically, cyclopentanone, γ-butyrolactone, cyclohexanone, ethyl lactate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, ethyl 3-ethoxypropionate, ethyl pyruvate, 2-ethoxyethyl acetate, acetic acid -2- (2-ethoxyethoxy) ethyl and propylene carbonate are mentioned.
In the present invention, the above solvents may be used alone or in combination of two or more.

In this invention, you may use the mixed solvent which mixed the solvent which has a hydroxyl group in a structure, and the solvent which does not have a hydroxyl group as an organic solvent.
Examples of the solvent having a hydroxyl group include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethyl lactate, and the like. Propylene glycol monomethyl ether and ethyl lactate are particularly preferred.
Examples of the solvent having no hydroxyl group include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide. Of these, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, and butyl acetate are more preferable, and propylene glycol monomethyl ether acetate, ethyl ethoxypropio Nate and 2-heptanone are particularly preferred.
The mixing ratio (mass) of the solvent having a hydroxyl group and the solvent having no hydroxyl group is from 1/99 to 99/1, preferably from 10/90 to 90/10, more preferably from 20/80 to 60/40. . A mixed solvent containing 50% by mass or more of a solvent having no hydroxyl group is particularly preferable 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 present in the main chain of the resin or may be substituted on the 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 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 (F2a) to (F4a),
R _{57 to} R ₆₈ each independently represents a hydrogen atom, a fluorine atom or an alkyl group. However, at least one of R _{57 to} R ₆₁ , R _{62 to} R ₆₄ and R _{65 to} R ₆₈ is a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom (preferably having a carbon number of 1 ~ 4). R _{57 to} R ₆₁ and R _{65 to} R ₆₇ are preferably all fluorine atoms. R _{62 to} R ₆₄ 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 (F2a) 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 (F3a) 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 1,3,3-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 (F4a) 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 the general formulas (CS-1) to (CS-3),
R _{12 to} R ₂₆ each independently represents a linear or branched alkyl group (preferably having 1 to 20 carbon atoms) 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 phenyl group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a urethane group or a urea group, or a combination of two or more groups. Can be mentioned.
n represents an integer of 1 to 5.

  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 each independently represents a hydrogen atom, a fluorine atom, an alkyl group (preferably having 1 to 4 carbon atoms) or a fluorinated alkyl group (preferably having 1 to 4 carbon atoms).
W _{1 to} W ₂ represent an organic group having at least one of a fluorine atom and a silicon atom.
R _{4 to} R ₇ each independently represents a hydrogen atom, a fluorine atom, an alkyl group (preferably having 1 to 4 carbon atoms) or a fluorinated alkyl group (preferably having 1 to 4 carbon atoms). 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 an alkyl group (preferably having 1 to 4 carbon atoms).
R ₉ represents an alkyl group (preferably having 1 to 4 carbon atoms) or a fluorinated alkyl group (preferably having 1 to 4 carbon atoms).
L < ₁ > -L < ₂ > represents a single bond or a bivalent coupling group, and is the same as said L < ₃ > -L < ₅ >.
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.
R ₃₀ and R ₃₁ each independently represents 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 represent a hydrogen atom, a fluorine atom, an alkyl group (preferably having 1 to 4 carbon atoms) or a fluorinated alkyl group (preferably having 1 to 4 carbon atoms).
W ₃ , W ₅ and W ₆ each represents an organic group having at least one of a fluorine atom and a silicon atom.
W ₄ represents a fluorine atom or an organic group having at least one of a fluorine atom and a silicon atom.
m represents an integer of 1 to 5.
n represents 0 or 1.

When W _{1 to} W ₆ are an organic group having a fluorine atom, the fluorinated linear, branched alkyl group or cycloalkyl group having 1 to 20 carbon atoms, or the fluorinated group having 1 to 20 carbon atoms. It is preferably a linear, branched, or cyclic alkyl ether group.

Examples of the fluorinated alkyl group for 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 an organic group having a silicon atom, an alkylsilyl structure or a cyclic siloxane structure is preferable. Specific examples include groups represented by the general formulas (CS-1) to (CS-3).

Specific examples of the repeating unit represented by the general formula (CI) are shown below. 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) Repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure
More preferably, a resin having only the 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 carbon atoms) To 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). More preferably, a copolymer resin of the repeating unit (a) and the repeating unit (c).
(D-4) a repeating unit (b) having a trialkylsilyl group or 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), Resin having 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) More preferably, a copolymer resin of the repeating unit (b) and the 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 cyclic siloxane structure, more preferably a repeating unit Copolymer resin of 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 cyclic siloxane structure, and a branched alkyl group (preferably Is a C4-20), cycloalkyl group (preferably C4-20), branched alkenyl group (preferably C4-20), cycloalkenyl group (preferably C4-20) or aryl. A resin having a repeating unit (c) having a group (preferably having 4 to 20 carbon atoms), more preferably a copolymer resin of repeating unit (a), repeating unit (b) and repeating unit (c).
Repeating unit (c) having a branched alkyl group, cycloalkyl group, branched alkenyl group, cycloalkenyl group, or aryl group in resins (D-3), (D-4), and (D-6) In consideration of hydrophilicity / hydrophobicity, interaction, etc., appropriate functional groups can be introduced, but from the viewpoint of immersion liquid follow-up and receding contact angle, functional groups that do not have polar groups Is preferred.
In the resins (D-3), (D-4), and (D-6), the repeating unit (a) having a fluoroalkyl group and / or the repeating unit (b) having a trialkylsilyl group or a cyclic siloxane structure is It is preferable that it is 20-99 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,
A branched alkyl group having 3 to 10 carbon atoms is more preferable.
R ₂ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, and 3 to 1 carbon atoms.
A linear or branched alkyl group of 0 is more preferable.

  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 (I).

In general formula (I),
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 the general formula (I), 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 (I), 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 (III).

In general formula (III):
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 general formula (III), 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 (II) and a repeating unit represented by the following general formula (III).

In general formulas (II) and (III):
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.
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 immersion liquid followability. The functional group is preferably not substituted, and more preferably unsubstituted.
L ₆ represents a single bond or a divalent linking group.
m and n represent a molar ratio of repeating units, and 0 <m <100 and 0 <n <100.

Rf in the general formula (II) is the same as Rf in the general formula (Ia).
The alkyl group represented by R ₃ 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.
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 (II) and the repeating unit represented by the general formula (III) 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, an alkyl group, or —O
It represents an SO ₂ -R _42. R ₄₂ represents an alkyl group, a cycloalkyl group or a camphor residue. R ₄₁
And the alkyl group of 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.
Glass transition temperature (Tg) is determined by differential scanning calorimete.
For example, it can be measured by analyzing the value of the change in specific volume when the sample is once heated and cooled and then heated again at 5 ° C./min.

  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) contains a hydrophilic polar group, the followability of immersion water tends to decrease, and 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 directly bonded to a carbon atom of the main chain as shown by the general formula (C-Id) is preferable because it may express a hydrophobic group.

  (X) Examples of alkali-soluble groups include phenolic hydroxyl groups, carboxylic acid 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 ( And a group having an alkylsulfonyl) 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%.

  The resin (D), like the 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. Preferably, this not only can further improve the sensitivity, resolution, process stability, pattern shape, and the like as a resist, but also provides a resist that does not change with time, such as foreign matter in liquid or sensitivity.

  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 polymerization method in which a monomer species and an initiator are dissolved in a solvent and the polymerization is performed by heating, 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, 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 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 the reaction 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 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 60-100 ° 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 hydrocarbon, the ratio of alcohol (particularly methanol) and other solvent (for example, ester such as ethyl acetate, ethers 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).

The resin may be once deposited and separated, and then 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) to (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.

Regarding the alkyl group, the alkyl group having a substituent is an aminoalkyl group (preferably having 1 to 20 carbon atoms), a hydroxyalkyl group (preferably having 1 to 20 carbon atoms), or a cyanoalkyl group (preferably having 1 carbon atom). ~ 20) is preferred.
R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ may be the same or different and each represents an alkyl group (preferably having 1 to 20 carbon atoms).
The alkyl groups in these general formulas (A) to (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. ] Undecar 7-ene etc. are mentioned. 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) sulfonium. Examples thereof include hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide, and 2-oxopropylthiophenium hydroxide. As the compound having an onium carboxylate structure, an anion portion of the compound having an onium hydroxide structure is converted to a carboxylate, and examples thereof include acetate, adamantane-1-carboxylate, and perfluoroalkylcarboxylate. Examples of the compound having a trialkylamine structure include tri (n-butyl) amine and tri (n-octyl) amine. Examples of the aniline compound 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.
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 preferably further contains (F) a surfactant, and is a fluorine-based and / or silicon-based surfactant (fluorine-based surfactant, silicon-based surfactant). , A surfactant having both a fluorine atom and a silicon atom), or more preferably two or more.

When the resist composition of the present invention contains the surfactant (F), when using an exposure light source of 250 nm or less, particularly 220 nm or less, a resist pattern with good sensitivity and resolution and less adhesion and development defects can be obtained. It becomes possible to give.
Examples of the fluorine-based and / or silicon-based surfactant 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, JP 2002-277862 A, US Patent Nos. 5,405,720, 5,360,692, 5,529,881, 5,296,330, 5,436,098, 5,576,143, 5,294,511, 5,824,451 Surfactant can be mentioned, The following commercially available surfactant can also be used as it is.
Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431, 4430 (manufactured by Sumitomo 3M Co., Ltd.),
Megafuck F171, F173, F176, F189, F113, F110, F177, F120, R08 (manufactured by Dainippon Ink and Chemicals), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass ( Co., Ltd.), Troisol S-366 (manufactured by Troy Chemical Co., Ltd.), GF-300, GF-150 (manufactured by Toagosei Co., Ltd.), Surflon S-393 (manufactured by Seimi Chemical Co., Ltd.), Ftop EF121, EF122A, EF122B, RF122C, EF125M, EF135M, EF351, 352, EF801, EF802, EF601 (manufactured by Gemco), PF636, PF656, PF6320, PF6520 (manufactured by OMNOVA), FTX-204G, 208, 230G, 204 , Mention may be made of 208D, 212D, 218D, the fluorine-based surfactant or silicone-based surfactants such as 222D ((KK) Neos). 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, the surfactant is derived from a fluoroaliphatic compound produced by a telomerization method (also called telomer method) or an oligomerization method (also called 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 polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. Or may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block link) or poly (block link of oxyethylene and oxypropylene) may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₃ F ₇ group and (poly (oxy) And a copolymer of (ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate).

  In the present invention, other surfactants other than fluorine-based and / or silicon-based surfactants can also be used. Specifically, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol ether, etc. Sorbitans such as polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate Fatty acid esters, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopal Te - DOO, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, may be mentioned polyoxyethylene sorbitan tristearate nonionic surfactants of polyoxyethylene sorbitan fatty acid esters such as such.

  These surfactants may be used alone or in several combinations.

  (F) The usage-amount of surfactant becomes like this. Preferably it is 0.01-10 mass% with respect to resist composition whole quantity (except a solvent), More preferably, it is 0.1-5 mass%.

(G) Carboxylic acid onium salt The resist composition in the present invention may contain (G) a carboxylic acid onium salt. Examples of the carboxylic acid onium salt include a carboxylic acid sulfonium salt, a carboxylic acid iodonium salt, and a carboxylic acid ammonium salt. In particular, the (G) carboxylic acid onium salt is preferably an iodonium salt or a sulfonium salt. Furthermore, it is preferable that the carboxylate residue of the (H) carboxylic acid onium salt of the present invention does not contain an aromatic group or a carbon-carbon double bond. As a particularly preferable anion moiety, a linear, branched, monocyclic or polycyclic alkylcarboxylic acid anion having 1 to 30 carbon atoms is preferable. More preferably, an anion of a carboxylic acid in which some or all of these alkyl groups are fluorine-substituted is preferable. The alkyl chain may contain an oxygen atom. This ensures transparency with respect to light of 220 nm or less, improves sensitivity and resolution, and improves density dependency and exposure margin.

  Fluoro-substituted carboxylic acid anions include fluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, pentafluoropropionic acid, heptafluorobutyric acid, nonafluoropentanoic acid, perfluorododecanoic acid, perfluorotridecanoic acid, perfluorocyclohexanecarboxylic acid, 2 , 2-bistrifluoromethylpropionic acid anion and the like.

  These (G) 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, and more preferably 1%, based on the total solid content of the composition. -7% by mass.

(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.

  In the pattern formation method of the present invention, a step of forming a film of a resin composition on a substrate, which increases the solubility in a positive developer and decreases the solubility in a negative developer by irradiation with actinic rays or radiation. The step of exposing the film, the step of heating the film, and the step of positive development of the film 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.
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 air, θ is the convergence angle of the light beam, and NA ₀ = sin θ. The resolution and the 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.

  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 material or impurities whose refractive index is significantly different from that of water are mixed with 193 nm light, the optical image projected on the resist is distorted, so that 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 manufacturing process of a circuit board such as a lithography process of other photo applications 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, alcohols and surfactants can be added in appropriate amounts 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, a 2.38% aqueous solution 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 ketone solvents 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- Use ester solvents such as ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate Can do.
Examples of alcohol solvents 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, n- Alcohols such as 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, propylene glycol, diethylene glycol monomethyl ether, triethylene glycol mono Examples include glycol ether solvents such as ethyl ether and methoxymethylbutanol.
Examples of the ether solvent include dioxane, tetrahydrofuran and the like in addition to the glycol ether solvent.
As the amide solvent, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, hexamethylphosphoric triamide, 1,3-dimethyl-2-imidazolidinone, etc. 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 those described above or water.

As a development method, a method of developing by raising the developer on the surface of the substrate by surface tension and allowing it to stand for a certain time (paddle method), a method of spraying the developer on the surface of the substrate (spray method), and rotating at a constant speed There are methods such as a method of continuously applying the developer while scanning the developer application nozzle on the substrate at a constant speed (dynamic dispensing method). When these development methods are used, the vapor pressure of the negative developer is used. Is high, the developer surface evaporates, the substrate surface is cooled, the temperature of the developer solution is lowered, the dissolution rate of the resist composition film formed on the substrate is not constant, and the dimensional uniformity deteriorates. To do. For this reason, the vapor pressure of the developer that can be used for negative development is preferably 5 kPa or less, more preferably 3 kPa or less, and most preferably 2 kPa or less at 20 ° C.
Specific examples having a vapor pressure of 5 kPa or less include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, 4-heptanone, 2-hexanone, diisobutylketone, 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 Ester solvents such as butyl acetate, 3-methyl-3-methoxybutyl acetate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, n-propyl Alcohol solvents such as 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, ethylene glycol, Glycol solvents such as diethylene glycol and triethylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol, propylene glycol, diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, glycol ether solvents such as methoxymethyl butanol, tetrahydrofuran Ether solvents such as N-methyl-2-pyrrolidone, N, N-dimethylacetami , N, N-dimethylformamide amide solvents, toluene, aromatic hydrocarbon solvents such as xylene, octane, aliphatic hydrocarbon solvents decane Ageraru.
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- Methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, ester solvents such as ethyl lactate, butyl lactate, propyl lactate, n-butyl alcohol, sec-butyl alcohol Alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, n-octyl alcohol, n-decanol and other alcohol solvents, ethylene glycol, diethylene glycol, triethylene glycol and other glycol solvents, Glycol ether solvents such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol, propylene glycol, diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methoxymethyl butanol, N-methyl-2-pyrrolidone, N, N-dimethyl Acetamide, amide solvents of N, N-dimethylformamide, aromatic hydrocarbon solvents such as xylene, aliphatic hydrocarbons such as octane and decane System solvent Ageraru.

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 development 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 applying the developer while scanning the developer application nozzle at a constant speed on a substrate rotating at a constant speed (dynamic dispensing method) ) Etc. can be applied.

  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.

  After washing with the rinse liquid, it is preferable to remove the rinse liquid from the substrate by rotating the substrate at a rotational speed of 2000 rpm to 4000 rpm. When the vapor pressure of the rinsing liquid is low, the rinsing liquid remains on the substrate even if the rinsing liquid is removed by rotating the substrate, and the residual rinsing liquid penetrates into the resist pattern formed on the substrate and the resist pattern swells. Therefore, the dimensional uniformity of the resist pattern is deteriorated. For this reason, the vapor pressure of the rinse liquid is preferably 0.05 kPa or more, more preferably 0.1 kPa or more, and most preferably 0.12 kPa or more at 20 ° C.

  In the rinsing step after negative development, a rinsing liquid containing at least one organic solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents is used. It is preferable to wash it. 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. More preferably, after the negative development, a step of washing with a rinse solution containing an alcohol solvent or an ester solvent is performed. Particularly preferably, after negative development, a step of washing with a rinsing solution containing a monohydric alcohol having 5 to 8 carbon atoms is performed. Here, examples of the monohydric alcohol having 5 to 8 carbon atoms used in the rinsing step after the negative development include linear, branched, and cyclic monohydric alcohols, and specifically, 1-pentanol. 2-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, etc. 1-hexanol, 2-hexanol, and 2-heptanol are preferable.

  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.

  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 method of the cleaning treatment is not particularly limited. For example, a method of continuously applying 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.

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

[Synthesis Example 1 (Synthesis of Resin (A1))]
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). γ-butyrolactone methacrylate, hydroxyadamantane methacrylate, 2-methyl-2-adamantyl methacrylate in a mixed solvent of 6/4 (mass ratio) of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether in a molar ratio of 45/15/40 It melt | dissolved and the 22 mass% monomer solution (200g) was prepared. 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 carried out 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 (A1). The obtained resin (A1) had a weight average molecular weight of 9,500 and a dispersity (Mw / Mn) of 1.80.

[Resist composition (A1)]
A positive resist composition obtained by dissolving the following components in a mixed solvent of polyethylene glycol monomethyl ether acetate / polyethylene glycol monomethyl ether (60:40) and filtering the solution with a solid content concentration of 5.8% by mass through a 0.1 μm polyethylene filter. A product (A1) was prepared.
Resin (A1) 1.83 g, triphenylsulfonium nonaflate 69.6 mg, diphenylaniline 8.7 mg, PF 6320 (fluorine surfactant manufactured by OMNOVA) 1.7 mg.

[Resist composition (A2)]
Instead of the resin (A1), the following resin (A2) was used to prepare a resist composition (A2).

[Resist composition (A3)]
Instead of the resin (A1), the following resin (A3) was used to prepare a resist composition (A3).

[Resist composition (A4)]
Instead of the resin (A1), the following resin (A4) was used to prepare a resist composition (A4).

[Resist compositions (A5) to (A9)]
Resist compositions (A5) to (A9) were prepared using the following resins (A5) to (A9) instead of the resin (A1), respectively.

[Resist composition (B)]
Instead of the resin (A1), the following resin (B) was used to prepare a resist composition (B).

[Resist compositions (C) and (D)]
Resist compositions (C) and (D) were prepared using the following resins (C) and (D) instead of the resin (A1).

[Example 1]
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 a 78 nm antireflection film. A resist composition (A1) was applied thereon, and baked at 120 ° C. for 60 seconds to form a 150 nm resist film. The obtained wafer was subjected to pattern exposure using an ArF excimer laser scanner (NA 0.75). After heating at 120 ° C. for 60 seconds, the wafer was developed with butyl acetate (negative developer) for 60 seconds using a spray method while rotating the wafer at a rotation speed of 1000 rpm (negative development), and 150 nm (1: A line and space resist pattern of 1) was obtained.

[Example 2]
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 a 78 nm antireflection film. A resist composition (A1) was applied thereon, and baked at 120 ° C. for 60 seconds to form a 150 nm resist film. The obtained wafer was subjected to pattern exposure using an ArF excimer laser scanner (NA 0.75). Then, after heating at 120 ° C. for 60 seconds, the wafer was rotated at 1000 rpm, developed with butyl acetate (negative developer) for 60 seconds using a spray method (negative development), and kept rotating. The wafer was rinsed with 1-hexanol for 30 seconds using a spray method, and then the wafer was rotated at 4000 rpm for 30 seconds to remove the rinsing liquid. A resist pattern was obtained.

[Examples 3-5, 8-13 and Comparative Examples 1-2]
A 150 nm (1: 1) line was obtained in the same manner as in Example 2 except that (A2) to (A9), (B), (C) and (D) were used as the resist compositions, respectively. An andspace resist pattern was obtained.

Example 6
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 a 78 nm antireflection film. A resist composition (A1) was applied thereon, and baked at 120 ° C. for 60 seconds to form a 150 nm resist film. The obtained wafer was subjected to pattern exposure using an ArF excimer laser scanner (NA 0.75). Then, after heating at 120 ° C. for 60 seconds, developed with an aqueous tetramethylammonium hydroxide solution (2.38% by mass) (positive developer) for 30 seconds (positive development), rinsed with pure water, pitch 600 nm, A pattern with a line width of 450 nm was obtained. Next, while rotating the wafer at a rotation speed of 1000 rpm, development is performed with butyl acetate (negative developer) for 60 seconds using a spray method (negative development). -After rinsing with hexanol for 30 seconds, the wafer was rotated at 4000 rpm for 30 seconds to remove the rinsing solution, thereby obtaining a 150 nm (1: 1) line-and-space resist pattern.

Example 7
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 a 78 nm antireflection film. A resist composition (A1) was applied thereon, and baked at 120 ° C. for 60 seconds to form a 150 nm resist film. The obtained wafer was subjected to pattern exposure using an ArF excimer laser scanner (NA 0.75). Then, after heating at 120 ° C. for 60 seconds, the wafer was rotated at 1000 rpm, developed with butyl acetate (negative developer) for 60 seconds using a spray method (negative development), and kept rotating. The wafer was rinsed with 1-hexanol for 30 seconds using a spray method, and then the wafer was rotated at a rotation speed of 4000 rpm for 30 seconds to remove the rinse liquid, thereby obtaining a pattern having a pitch of 600 nm and a line width of 450 nm. . Next, the film was developed with a tetramethylammonium hydroxide aqueous solution (2.38% by mass) (positive developer) for 30 seconds (positive development), rinsed with pure water, and 150 nm (1: 1) line and space. A resist pattern was obtained.

<Evaluation of line edge roughness (LER)>
The 150 nm (1: 1) line and space resist patterns obtained in Examples 1 to 13 and Comparative Examples 1 and 2 were observed using a length measurement scanning electron microscope (S-9260 manufactured by Hitachi, Ltd.). In the range of the edge of 2 μm in the longitudinal direction of the 150 nm line pattern, the distance from the reference line where the edge should be was measured at 50 points, the standard deviation was obtained, and 3σ was calculated. A smaller value indicates better performance. The results are shown in Table 1 below.

[Examples 14 to 27 and Comparative Examples 3 to 4]
A 150 nm (1: 1) line-and-space resist pattern was obtained in the same manner as in Example 7 except that the combinations of the negative developer and the rinsing solution for negative developer were changed to the combinations shown in Table 3 below. It was.

Example 28
A 150 nm (1: 1) line-and-space resist pattern was obtained in the same manner as in Example 7 except that (B) was used as the resist composition.

  Table 2 shows the vapor pressure and boiling point of the negative developing solvent and the negative rinsing solvent used in Examples and Comparative Examples.

<Evaluation of dimensional uniformity>
Using a scanning microscope (S-9260, manufactured by Hitachi, Ltd.), the dimensions of 50 locations of the 150 nm (1: 1) line and space resist patterns obtained in Examples 14 to 28 and Comparative Examples 3 to 4 were measured. Then, 50 standard deviations were obtained and 3σ was calculated. A smaller value indicates better performance. The results are shown in Table 3. The mass ratio in Table 3 is the mixture mass ratio of the two types of solvents when two types of organic solvents are used together as a negative developer or when two types of organic solvents are used as a negative developer rinse. To express. The mass ratio when the negative developing solution or the negative developing rinsing solution is composed of a single organic solvent is 100.

  From Table 3, the combination of the resist composition of the present invention with a negative developer and a rinsing solution for negative developer reduces line edge roughness, and stably produces a highly accurate fine pattern with excellent dimensional uniformity. Can be formed.

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.

Explanation of symbols

1 Irradiation Light 2 Exposure Mask 3 Pattern 4 Wafer

Claims (9)

(A) The process of apply | coating the resist composition containing resin which has a repeating unit represented by the following general formula (NGH-1), increases polarity by the effect | action of an acid, and the solubility with respect to a negative developing solution decreases. ,
(A) A pattern forming method comprising an exposure step and (d) a development step using a negative developer.

In the general formula (NGH-1),
R _NGH1 represents a hydrogen atom or an alkyl group.
R _{NGH2 to} R _NGH4 each independently represent a hydrogen atom or a hydroxyl group. However, at least one of R _{NGH2 to} R _NGH4 represents a hydroxyl group.   The step of developing using a negative developer is a step of using a negative developer containing an organic solvent and having a vapor pressure at 20 ° C. of 5 kPa or less. Pattern forming method. The pattern forming method according to claim 1, further comprising (f) a step of washing with a negative developing rinse containing an organic solvent.   The step of washing with a negative developing rinse containing an organic solvent is a step of using a negative developing rinse containing an organic solvent and having a vapor pressure at 20 ° C. of 0.1 kPa or higher. The pattern forming method according to claim 3. 5. The pattern forming method according to claim 1, further comprising (c) a step of developing using a positive developer. (A) Resin which has a repeating unit represented by the following general formula (NGH-1), increases in polarity by the action of an acid, and decreases in solubility in a negative developer, (B) irradiation with actinic rays or radiation A negative developing resist composition comprising a compound capable of generating an acid and (C) a solvent.

In the general formula (NGH-1),
R _NGH1 represents a hydrogen atom or an alkyl group.
R _{NGH2 to} R _NGH4 each independently represent a hydrogen atom or a hydroxyl group. However, at least one of R _{NGH2 to} R _NGH4 represents a hydroxyl group. (A) Resin having a repeating unit represented by the following general formula (NGH-1), having increased polarity by the action of an acid, decreased solubility in a negative developer, and increased solubility in a positive developer (B) A resist composition for multiple development, comprising a compound that generates an acid upon irradiation with actinic rays or radiation, and (C) a solvent.

In the general formula (NGH-1),
R _NGH1 represents a hydrogen atom or an alkyl group.
R _{NGH2 to} R _NGH4 each independently represent a hydrogen atom or a hydroxyl group. However, at least one of R _{NGH2 to} R _NGH4 represents a hydroxyl group.   The negative developer for use in the pattern forming method according to claim 1, comprising an organic solvent and having a vapor pressure at 20 ° C. of 5 kPa or less.   The rinsing solution for negative development used in the pattern forming method according to claim 3, comprising an organic solvent and having a vapor pressure at 20 ° C. of 0.1 kPa or more.

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