TWI446112B - 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

Description

Pattern forming method, photoresist composition for the pattern forming method, negative developer for the pattern forming method, and negative developer cleaning solution for the pattern forming method

The present invention relates to a pattern forming method that can be used to fabricate semiconductors (such as ICs), liquid crystals or circuit boards (such as heating heads), and other optical applications of lithography, and a negative development light for the pattern forming method. A resist composition, a resist for multiple development of the pattern forming method, a negative developer for the pattern forming method, and a negative developer for use in the pattern forming method. In particular, it relates to a pattern forming method which can be suitably used for exposure using an ArF exposure apparatus and an immersion type projection exposure apparatus in which far ultraviolet light having a wavelength of 300 nm or less is used as a light source, and a method for A photoresist composition of a pattern forming method, a negative developing solution for the pattern forming method, and a negative developing developing solution for the pattern forming method.

After developing a photoresist for a KrF excimer laser beam (248 nm), a so-called chemically amplified image forming method has been used, which is a photoresist image forming method for compensating for a decrease in sensitivity due to light absorption. In a positive chemical amplification method for forming an image, for example, an acid generator decomposes to form an acid upon exposure of an exposed portion. In post-exposure bake (PEB: post-exposure bake), the acid thus produced is used as a reaction catalyst, thus converting an alkali-insoluble group into an alkali-soluble group. Therefore, the exposed portion is removed by alkali development to form an image.

With the recent fine patterning of semiconductors, attempts have been made to shorten the wavelength of the exposure source and increase the numerical aperture (high NA) of the projection lens. Has developed one An exposure apparatus using a 193 nm ArF excimer laser beam as a light source. As is well known, this device can be represented by the following formula.

(resolution) = k ₁ . (λ/NA)

(focus depth) = ± k ₂ . λ/NA ²

In the above formula, λ represents the wavelength of the exposure source; NA represents the numerical aperture of the projection lens; and k ₁ and k ₂ represent the coefficients for this method.

As a technique for improving the resolution, a so-called impregnation method in which a liquid having a high refractive index (hereinafter also referred to as "impregnation liquid") is filled between a projection lens and a sample is known.

Considering this "impregnation effect", the above resolution and depth of focus can be expressed by the following formula, where λ ₀ represents the exposure wavelength in air, n represents the refractive index of the air immersed in the liquid, and θ represents the convergence half angle of the light, and NA ₀ means sin θ.

(resolution) = k ₁ . (λ ₀ /n)/NA ₀

(focus depth) = ± k ₂ . (λ ₀ /n)/NA ₀ ²

That is, the impregnation effect is equal to the exposure using a wavelength of 1/n. In other words, in the case of using the same projection optical system as NA, the immersion can increase the depth of focus by n times. It is effective for any pattern, and can be combined with super-analytical techniques currently being studied, such as phase shifting and anamorphic lighting.

In order to further improve the resolution, a double exposure technique and a double patterning technique have been proposed, which are considered as techniques for improving the resolution by reducing k ₁ in the above equation regarding the resolution.

In order to pattern an electronic device such as a semiconductor, it has been practiced to use a reduced projection exposure device to transfer the pattern of the reticle or reticle (where the target pattern has been magnified 4 to 5 times) onto the substrate (such as a wafer) to be exposed. .

However, with recent fine patterning, existing exposure systems have optical interference in adjacent patterns, thus reducing the problem of optical contrast. In order to overcome this problem, these techniques have attempted to divide the reticle design into a plurality of reticle patterns and separately expose the individual reticles, thereby forming an image. This dual exposure system requires splitting the reticle design and recombining the patterns on the substrate to be exposed (eg, wafer) to form an image. Therefore, the reticle design should be segmented in such a way as to ensure reliable reticle pattern reproduction.

The patent JP-A-2006-156422 shows the effect of this double exposure system on the effect of fine image pattern shifting.

Further recent advances in dual exposure techniques are reported in SPIE Proc 5754, 1508 (2005), SPIE Proc 5377, 1315 (2005), SPIE Proc 61531 K-1 (2006), and the like.

In the case where a pattern is formed only by coating the existing photoresist composition of the existing photoresist method, since the pattern should be formed close to the resolution limit of the photoresist in the double exposure system, it is impossible to have a sufficient exposure range or a sufficient depth of focus. Get the problem.

That is, a dual exposure system application includes coating a substrate with a photoresist composition containing a resin having an increased polarity upon exposure, exposure, and a pattern forming method developed by dissolving an exposed portion of the photoresist film with an alkaline developing solution, such as JP -A-2001-109154, or the like, or comprising coating a substrate with a photoresist composition containing a resin having an increased molecular weight upon exposure, exposing, and dissolving the unexposed portion of the photoresist film with an alkaline developing solution. A method of forming a developed pattern, as reported in JP-A-2003-76019, etc., cannot establish sufficient resolution performance.

As for the g-line, i-line, KrF, ArF, EB, and EUV lithography developer, a 2.38 mass% alkaline aqueous developer of TMAH (tetramethylammonium hydroxide) was recently used.

As for the developing solution other than the above, for example, JP-A-2001-215731 discloses a developing solution for dissolving and developing an exposed portion of a photoresist material containing a copolymer composed of an ethylene-based monomer and an acrylic monomer. It contains an aliphatic linear ether solvent or an aromatic ether solvent and a ketone (having 5 or more carbon atoms) solvent. JP-A-2006-227174 discloses a developer for dissolving and developing an exposed portion of a photoresist material (breaking of a polymer chain upon irradiation), which is characterized by containing an acetate group, a ketone, an ether, and a phenyl group. Two or more and having a molecular weight of 150 or more. JP-A-6-194847 discloses a photoresist material (by reacting a polyhydroxy ether resin with glycidyl (meth) acrylate) containing a photosensitive polyhydroxy ether resin as a main component. An unexposed partially developed developing solution characterized by using a solvent mixture having an aromatic compound of 6 to 12 carbon atoms or an aromatic compound having 50% by mass or more and having 6 to 12 carbon atoms as a developing solution.

However, the combination of these photoresist compositions and developer provides only one system in which a specified photoresist composition is combined with a highly polar alkaline developer or a developer containing a low polarity organic solvent to form a pattern.

That is, the positive type system (the combination of the photoresist composition and the positive type developing solution) provides only a material which forms a pattern by selectively dissolving and removing a region which is a high light irradiation intensity in an optical hologram (light intensity distribution), As shown in Figure 1. On the other hand, the negative type system only provides a material which forms a pattern by selectively dissolving and removing low light irradiation intensity regions.

The term "positive developing solution" as used herein means a developing solution by which it selectively dissolves and removes an exposed portion located at or above a defined critical value (as indicated by the solid line in Fig. 1). The term "negative developer" as used herein refers to a developer by which it selectively dissolves and removes exposed portions below a defined threshold. The development step using a positive developer is referred to as positive development (also referred to as a positive development step), and the development step using a negative developer is referred to as negative development (also referred to as a negative development step).

JP-A-2000-199953 discloses a dual development technique as a double patterning technique for improving resolution. In this case, a common image is formed by using chemical amplification. By utilizing the phenomenon that the polarity of the resin in the photoresist composition is increased by exposure in the high light intensity region and lowered in the low light intensity region, the positive development system dissolves the specified photoresist film by developing the developer with high polarity. The high-exposure region is performed, and the negative development is performed by dissolving the low-exposure region with a developer having a low polarity. More specifically, it uses an alkaline aqueous solution as a positive developing solution to dissolve an area in which the exposure dose of the irradiation light 1 is E2 or more, and dissolves the exposure amount as E1 using a specified organic solvent as a negative developing solution. Or smaller areas, as shown in Figure 2. The area where the medium exposure dose (E2 to E1) is left is the undeveloped area, and the L/S pattern 3 having the pitch of the half of the exposure mask pattern 2 formed on the wafer 4 is as shown in Fig. 2 .

In the above case, however, it uses a third butyl group as an acid decomposable group in the resin contained in the photoresist composition. Therefore, it is impossible to exhibit a polarity change sufficient to cause a difference in solubility characteristics due to a chemical amplification reaction attached to the exposure.

In addition, a resin having a styrene skeleton is used as a photoresist composition. Resin, the low exposure area of the photoresist film has high polarity. As a result, development using a negative type developing solution is performed only at a low development speed, which causes a problem that deterioration of development properties using a negative type developing solution.

In order to solve the above problems and to form a highly accurate and fine pattern stably, thereby manufacturing a highly integrated and highly precise electronic device, it is an object of the present invention to provide a pattern forming method which can alleviate the thickness of a line edge and improve dimensional stability.

The present invention has the following constitution, whereby the above object according to the present invention can be achieved.

<1> A pattern forming method comprising: (a) coating a photoresist composition comprising a resin comprising a repeating unit represented by the following formula (NGH-1) and increasing polarity and decreasing by an action of an acid; Solubility in negative developer; (b) exposure; and (d) development with negative developer:

Wherein R _NGH1 represents a hydrogen atom or an alkyl group; and R _NGH2 to R _NGH4 each independently represent a hydrogen atom or a hydroxyl group, provided that at least one of R _NGH2 to R _NGH4 represents a hydroxyl group.

<2> The pattern forming method according to <1>, wherein the negative type developing solution comprises an organic solvent and has a vapor pressure of 5 kPa or less at 20 °C.

<3> The pattern forming method according to <1>, which further comprises: (f) washing with a negative-type developing washing liquid including an organic solvent.

<4> The pattern forming method according to <3>, wherein the negative-type developing washing liquid has a vapor pressure of 0.1 kPa or more at 20 °C.

<5> The pattern forming method according to <1>, which further comprises: (c) developing with a positive developer.

<6> A negative-type developing photoresist composition comprising: (A) a repeating unit represented by the following formula (NGH-1) and increasing polarity due to an action of an acid and lowering solubility in a negative developing solution a resin; (B) a compound which produces an acid upon irradiation with actinic radiation or radiation; and (C) a solvent:

Wherein R _NGH1 represents a hydrogen atom or an alkyl group; and R _NGH2 to R _NGH4 each independently represent a hydrogen atom or a hydroxyl group, provided that at least one of R _NGH2 to R _NGH4 represents a hydroxyl group.

<7> A photoresist composition for multiple development comprising: (A) a repeating unit represented by the following formula (NGH-1) and having a polarity due to an action of an acid to lower the solubility in a negative developing solution, And a resin which increases the solubility in the positive developing solution; (B) a compound which generates an acid upon irradiation with actinic rays or radiation; and (C) a solvent:

Wherein R _NGH1 represents a hydrogen atom or an alkyl group; and R _NGH2 to R _NGH4 each independently represent a hydrogen atom or a hydroxyl group, provided that at least one of R _NGH2 to R _NGH4 represents a hydroxyl group.

<8> A pattern forming method according to <1>, which comprises a negative developing solution comprising an organic solvent and having a vapor pressure of 5 kPa or less at 20 °C.

<9> A washing liquid for negative pattern development of the pattern forming method according to <3>, which comprises an organic solvent and has a vapor pressure of 0.1 kPa or higher at 20 °C.

Next, the best mode for carrying out the invention will be described.

In the group (atomic group) described herein, those which are not shown as substituted or unsubstituted include an unsubstituted group and a group having a substituent. Such as the noun "alkyl" package The alkyl group (unsubstituted alkyl group) having an unsubstituted group and the alkyl group (substituted alkyl group) having a substituent are included.

The meaning of the nouns used herein will first be described. The pattern forming method is divided into a positive type system and a negative type system. Although the solubility of the photoresist film in the developer is changed by the chemical reaction induced by light irradiation in both systems, the irradiated portion is dissolved in the developer in the positive system and the unirradiated portion in the negative system. Dissolved in the developer. Here, two types of developing solutions, a negative developing solution and a positive developing solution, are used. The positive developer is a developer which selectively dissolves and removes the exposed portion above the critical value indicated by the solid line in Fig. 1. The negative developer is a developer by which it selectively dissolves and removes the exposed portion below the defined critical value. The development step using a positive developer is referred to as positive development (also referred to as a positive development step), and the development step using a negative developer is referred to as negative development (also referred to as a negative development step). The development system in which the above-described development step using a positive developer is combined with the above-described development step using a negative developer is referred to as multiple development (also referred to as multiple development step). In the present invention, the photoresist composition for negative development is referred to as a negative development photoresist composition, and the photoresist composition for multiple development is referred to as a multiple development photoresist composition. Only the "photoresist composition" is a photoresist composition for negative development and a photoresist composition for multiple development. The negative development cleaning liquid represents a washing liquid containing an organic solvent used in the washing step after the negative development step.

As for the technique for improving the resolution, the present invention proposes a novel pattern forming method in which a developing solution (negative type developing solution) which selectively forms and dissolves an exposed portion under the threshold value (b) is selectively dissolved and removed as shown in FIG. ),group A negative-type developing photoresist composition containing a resin having a repeating unit represented by the following formula (NGH-1) and exhibiting an increase in polarity due to the action of an acid and a decrease in solubility in a negative developing solution.

In the formula (NHG-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, provided that at least one of R _NGH2 to R _NGH4 represents a hydroxyl group.

As for the technique for improving the resolution, the present invention preferably proposes a novel pattern forming method in which a developing solution (positive developing solution) which selectively dissolves and removes an exposed portion above a critical value (a), and By selectively dissolving and removing the developing solution (negative developing solution) defining the exposed portion below the critical value (b), the resin-containing compound (having a repeating unit represented by the following general formula (NGH-1) and having an acid The dual development photoresist composition exhibits an increase in polarity, a decrease in solubility in a negative developer, and an increase in solubility in a positive developer.

When the pattern element on the exposure mask is projected onto the wafer by light irradiation, as shown in FIG. 3, the positive developing solution is used to dissolve and remove the high irradiation intensity region (the exposure portion above the threshold value (a) is defined. And use a negative developer to dissolve and remove areas of low illumination intensity (defining the exposed portion below the threshold (b)). This gives a pattern with a resolution up to twice the optical full-image frequency. . Furthermore, it is not necessary to divide the exposure reticle design in accordance with the method of the present invention.

As for the photoresist composition for multiple development which simultaneously performs the above two or more development steps, it is possible to directly use the photoresist composition for negative development.

The pattern forming method required for carrying out the invention comprises the steps of: (a) coating a photoresist composition comprising a resin having a repeating unit represented by the following formula (NGH-1) and acting on the acid The display polarity is increased and the solubility in the negative developer is lowered; (b) the exposure step; and (d) the step of developing using the negative developer:

In the formula (NGH-1), R _NGH1 represents a hydrogen atom or an alkyl group. _R NGH2 to _R NGH4 each independently represents a hydrogen atom or a hydroxyl group, with the proviso that at least one represents a hydroxyl group _R NGH2 to _R NGH4.

Preferably, the pattern forming method according to the present invention further comprises (f) a step of washing with a negative-type developing washing liquid containing an organic solvent.

Preferably, the pattern forming method according to the present invention further comprises (c) a step of developing using a positive developer.

Preferably, the pattern forming method according to the present invention further comprises (e) a step of heating after (b) the exposing step.

In the pattern forming method according to the present invention, (b) the exposing step can be performed repeatedly.

In the pattern forming method according to the present invention, the (e) heating step can be performed a plurality of times.

In order to carry out the present invention, there is a need for a resin containing resin (having a repeating unit represented by the following formula (NGH-1) and exhibiting an increase in polarity due to the action of an acid and a decrease in solubility in a negative developing solution), a negative developing solution ( Preferably, it is an organic developer) and a photoresist composition for a negative developer (which preferably contains an organic solvent).

In the 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, provided that at least one of R _NGH2 to R _NGH4 represents a hydroxyl group.

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

In the pattern forming method using two developing solutions (i.e., a positive developing solution and a negative developing solution), the developing order is not particularly limited. It is preferred to perform the first development using a positive developer or a negative developer after the first exposure, and then perform negative or positive development using a developer which is different from the first development. It is also preferred to use a negative-type developing cleaning liquid containing an organic solvent after the negative development.

Patterning systems include (a) systems that employ chemical reactions (such as polarity changes), and (b) systems that use bond formation in molecules (such as cross-linking or polymerization).

In a photoresist material whose molecular weight is increased due to bond formation (eg, crosslinking or polymerization) in a molecule, it is difficult to constitute a single photoresist material for one developer as a positive photoresist but another developer as a negative photoresist. The system.

The photoresist composition according to the present invention is "a photoresist composition having a repeating unit represented by the following formula (NGH-1) and exhibiting an increase in polarity due to the action of an acid and a decrease in solubility in a negative developing solution".

The resin contained in the photoresist composition according to the present invention shows an increase in polarity due to the action of an acid. As a result, it was revealed that not only the solubility in the negative developer was lowered, but also the solubility in the alkaline developer was increased.

Therefore, the photoresist composition according to the present invention acts as a negative photoresist for a negative developer but as a positive photoresist for a positive developer.

In the present invention, an organic developing solution containing an organic solvent can be used as a negative developing solution, and an alkaline (aqueous) developing solution can be used as a positive developing solution.

Controlling the "threshold value" of the exposure dose (i.e., the exposure dose at which the film becomes soluble or insoluble in the light-irradiated region) is important to the present invention. In order to obtain a desired line width in pattern formation, the minimum exposure amount in which the film is soluble in the positive developer and the maximum exposure amount in which the film is insoluble in the negative developer are regarded as "critical values".

The "threshold value" can be determined as follows.

In order to obtain a desired line width in pattern formation, the minimum exposure amount in which the film is soluble in the positive developer and the maximum exposure amount in which the film is insoluble in the negative developer are regarded as "critical values".

More strictly speaking, the critical values are as defined below.

When measuring the ratio of the residual film of the photoresist film to the exposure dose, the exposure dose which is 0% of the residual film ratio of the positive developer is referred to as the critical value (a), and the residual film ratio of the negative developer is determined. The exposure dose of 100% is called the critical value (b), as shown in Fig. 4.

For example, by changing the film to a threshold value (a) of the exposure amount soluble in the positive developer, it is controlled to a level higher than the critical value (b) of the exposure amount of the film which becomes soluble in the negative developer, as in the fifth. As shown, the pattern can be made with a single exposure. As shown in Fig. 6, the wafer to which the photoresist is applied is exposed, and the positive developing solution is first used to dissolve the portion above the critical value (a) of the exposure dose. Next, the negative developing solution is used to dissolve the portion below the critical value (b) of the exposure dose. Thus, pattern formation can be accomplished by a single exposure. In this case, the development of the positive and negative developers can be carried out in any order. An improved pattern can be obtained by washing with a washing solution containing an organic solvent after negative development.

As for the method of controlling the critical value, it is possible to use a method including controlling parameters regarding materials such as a photoresist composition and a developing solution, and parameters relating to the program.

As for the parameters of the material, it is effective to control various physical values (i.e., SP value (solubility parameter), LogP value, etc.) regarding the solubility of the photoresist composition in the developer and the organic solvent. Specific examples thereof include a weight average molecular weight, a weight average dispersibility, a monomer composition ratio, a monomer polarity, a monomer sequence, and a polymer blend of a polymer contained in the photoresist composition, and a low molecular weight additive (if included) The concentration of the developer, the low molecular weight additive (if included), the surfactant (if included), and the like.

Examples of the parameters of the program include a film formation temperature, a film formation time, a temperature and time of heating after exposure, a development temperature, a development time, a nozzle system of a developing device (solution spraying method), a post-development washing method, and the like.

Therefore, in order to obtain an excellent pattern by a pattern forming method using negative development and a pattern forming method using multiple development (which uses a combination of negative development and positive development), the above parameters regarding the material and parameters regarding the program are appropriately controlled. The combination is important.

In the pattern forming method using two types of developing solutions (i.e., positive developing solution and negative developing solution), the exposure can be performed once as in the above examples. Or the exposure can be performed multiple times. In the latter case, the first exposure is performed after development using a positive or negative developer, and then double exposure is performed after development using a developer different from that used for the first exposure.

The advantage of performing exposure two or more times is that the threshold value for development after the first exposure can be controlled with a higher degree of freedom, and the threshold value for development after the double exposure can be controlled. In the case where exposure is performed two or more times, it is desirable that the exposure dose of the double exposure is higher than the exposure dose of the first exposure. In the secondary development, as shown in Fig. 7, the critical value is determined based on the history of the first and second exposure doses. When the exposure dose of the double exposure is sufficiently higher than the exposure dose of the first exposure, the exposure dose of the first exposure has only a small effect, which is negligible in some cases.

It is desirable that the exposure dose (Eo1 [mJ/cm^2]) of the first exposure step is 5 [mJ/m2] or less lower than the exposure dose (Eo2 [mJ/cm2]) of the second exposure step. This can reduce the influence of the first exposure history on the method of forming the double exposure pattern.

In order to change the first exposure dose and the double exposure dose, it is effective to use the above methods for controlling various parameters regarding materials and procedures. It is particularly effective to control the temperature of the first heating step and the temperature of the second heating step. In order to make the first exposure dose lower than the second exposure dose, it is effective to perform the first heating step at a temperature lower than the second heating step.

In practical lithography, the critical value (a) of positive development is as follows.

A film of a photoresist composition containing a resin having a repeating unit represented by the following formula (NGH-1) and exhibiting an increase in polarity due to the action of an acid and a decrease in solubility in a negative developing solution is formed on the substrate. The film is then exposed to the reticle having the desired pattern size under the desired lighting conditions. In this step, the exposure focus was changed at intervals of 0.05 [micrometers] and the exposure dose was changed at intervals of 0.5 [millijoules/cm 2 ]. After exposure, the film is heated at the desired temperature for the desired time and developed with the desired concentration of alkaline developer for the desired time. After development, it uses a CD-SEM to measure the line width of the pattern such that the exposure dose A [mJ/cm2] is determined and the focal position of the desired line width is formed. The film is then illuminated through the reticle at a specified exposure dose A [milli joules per square centimeter] and a specified focal position, and the intensity distribution of the optical image is calculated. The calculation can be done using the simulation software (Prolith ver. 9.2.0.15 manufactured by KLA). The detailed calculation method is described in Inside PROLITH (Chris, A. Mack, FINLE Technologies, Inc., Chapter 2, Aerial Image Formation).

Fig. 8 shows an example of the holographic intensity distribution of the optical image as a calculation data.

As shown in Figure 9, the total image position is divided from the holographic intensity of the optical image. The cloth minimum is offset by half of the resulting line width and the light intensity at the determined position corresponds to a critical value (a).

In practical lithography, the critical value (b) of negative development is as follows.

A film of a photoresist composition containing a resin having a repeating unit represented by the following formula (NGH-1) and exhibiting an increase in polarity due to the action of an acid and a decrease in solubility in a negative developing solution is formed on the substrate. The film is then exposed to the reticle having the desired pattern size under the desired lighting conditions. In this step, the exposure focus was changed at intervals of 0.05 [micrometers] and the exposure dose was changed at intervals of 0.5 [millijoules/cm 2 ]. After exposure, the film is heated at the desired temperature for the desired time and developed with the desired concentration of alkaline developer for the desired time. After development, it uses a CD-SEM to measure the line width of the pattern such that the exposure dose A [mJ/cm2] is determined and the focal position of the desired line width is formed. The film is then illuminated through the reticle at a specified exposure dose A [milli joules per square centimeter] and a specified focal position, and the intensity distribution of the optical image is calculated. Calculations can be done using simulation software (made by KLA).

Fig. 10 shows an example of the holographic intensity distribution of the optical image as a calculation data.

As shown in Fig. 11, the light intensity at the position determined by shifting the total image position from the maximum of the total image intensity distribution of the optical image to the half of the obtained pattern line width corresponds to the critical value (b).

The critical value (a) is preferably from 0.1 to 100 [mJ/cm 2 ], more preferably from 0.5 to 50 [mJ/cm 2 ], and still more preferably from 1 to 30 [mJ/cm 2 ]. The critical value (b) is preferably from 0.1 to 100 [mJ/cm 2 ], more preferably from 0.5 to 50 [mJ/cm 2 ], and more preferably 1 Up to 30 [mJ/cm2].

The difference between the critical value (a) and the critical value (b) is preferably from 0.1 to 80 [mJ/cm 2 ], more preferably from 0.5 to 50 [mJ/cm 2 ], and still more preferably from 1 to 30. [milli joules per square centimeter].

In the present invention, the film formed on the substrate is coated with a resin containing a repeating unit represented by the following formula (NGH-1) and exhibits an increase in polarity due to the action of an acid and solubility in a negative developing solution. A film formed by reducing the photoresist composition.

In the 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, provided that at least one of R _NGH2 to R _NGH4 represents a hydroxyl group.

Next, the photoresist composition which can be used in the present invention will be described.

(A) A resin having a repeating unit represented by the formula (NGH-1) and exhibiting an increase in polarity due to the action of an acid and a decrease in solubility in a negative developing solution.

The photoresist composition according to the present invention contains a resin having a repeating unit represented by the general formula (NGH-1) and exhibiting an increase in polarity due to the action of an acid and a decrease in solubility in a negative developing solution (hereinafter also referred to as "resin (A) )").

In the general formula _(NGH1), 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, provided that at least one of R _NGH2 to R _NGH4 represents a hydroxyl group.

The alkyl group represented by R _{NGH1 in the} formula (NGH-1) is preferably an alkyl group having 1 to 4 carbon atoms which may be substituted with a fluorine atom, a hydroxyl group or the like.

As for R _NGH1 , it is preferably a hydrogen atom, a methyl group or an ethyl group. R _{NGH1 is more} preferably a methyl group.

Preferably, one or both of R _NGH2 to R _NGH4 is a hydroxyl group, and the balance is a hydrogen atom.

The content of the repeating unit represented by the formula (NGH-1) is preferably from 1 to 15 mol%, and more preferably from 5 to 15 mol%. The compatibility of the photoresist composition with the negative developer and the positive developer can be improved by controlling the content to 1 to 15 mol%.

Since it contains a repeating unit represented by the general formula (NGH-1), it can improve the adhesion of the resin (A) to the substrate.

Next, a specific example of a repeating unit represented by the general formula (NGH-1) is proposed, although the invention is not limited thereto.

The resin (A) is a resin which exhibits an increase in polarity due to the action of an acid.

It is preferred that the resin (A) is a group having an alkali-soluble group (hereinafter sometimes referred to as an "acid-decomposable group") which forms an alkali-soluble group in a main chain or a side chain of a resin or a main chain and a side chain by an action of an acid. Thus, a resin having an increased polarity is shown.

The resin (A) shows a decrease in solubility in the negative developer due to the action of the acid due to an increase in polarity due to the action of the acid.

The resin (A) shows an increase in solubility in the positive developer due to the action of the acid due to an increase in polarity due to the action of the acid.

As the acid-decomposable group, it is preferably a group in which a hydrogen atom in the alkali-soluble group is substituted by a group which is desorbed by the action of an acid.

Examples of the alkali-soluble group include a phenolic hydroxyl group, a carboxylic acid group, a fluoroalcohol group, a sulfonic acid group, a sulfonylamino group, a sulfonyl fluorenylene group, an (alkylsulfonyl) (alkylcarbonyl) methylene group. (alkylsulfonyl)(alkylcarbonyl)indolimide, anthracene (alkylcarbonyl)methylene, anthracene (alkylcarbonyl) fluorenylene, anthracene (alkylsulfonyl) methylene And anthracene (alkylsulfonyl) quinone imine group, ginseng (alkylcarbonyl) methylene group, ginseng (alkylsulfonyl) methylene group and the like.

Preferable examples of the alkali-soluble group include a carboxylic acid group, a fluoroalcohol group (preferably hexafluoroisopropanol), and a sulfonic acid group.

The group desorbed by the action of acid includes -C(R ₃₆ )(R ₃₇ )(R ₃₈ ), -C(R ₃₆ )(R ₃₇ )(R ₃₉ ) and -C(R ₀₁ )(R ₀₂ )(R ₃₉ ) Wait.

In these formulas, R ₃₆ to R ₃₉ each independently represent an alkyl group, a cycloalkyl group, an aryl group, an arylalkyl 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 represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group.

As the acid-decomposable group, it is preferably a cumene ester group, an enol ester group, an acetal ester group, a tertiary alkyl ester group or the like, and still more preferably a tertiary alkyl ester group.

Preferably, the resin (A) is a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure, exhibiting a decrease in solubility in a negative developing solution due to an acid action, and an increase in solubility in a positive developing solution (hereinafter sometimes referred to as a resin). "Aromatic hydrocarbons are main acid decomposable resins").

This is because the polarity of the resin changes greatly before and after irradiation with actinic rays or radiation due to the monocyclic or polycyclic alicyclic hydrocarbon structure. As a result, the contrast can be improved when developing with a negative developing solution (preferably an organic solvent) and a positive developing solution (preferably an alkaline developing solution).

Further, a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure generally has a high hydrophobic nature. Therefore, when a low-light irradiation intensity region is developed using a negative developer (preferably an organic solvent), a high development speed and improved development properties can be obtained by using a negative developer.

The photoresist composition according to the present invention containing an alicyclic hydrocarbon as a main acid-decomposable resin can be suitably used in the case of irradiation with an ArF excimer laser beam.

Preferably, the alicyclic hydrocarbon is a main acid-decomposable resin which is a resin containing at least one repeating unit selected from the group consisting of a partial structure having an alicyclic hydrocarbon represented by one of the following general formulae (pI) to (pV). A repeating unit and a repeating unit represented by the following formula (II-AB).

In the general formulae (pI) to (pV), R ₁₁ represents an alkyl group.

Z represents an atomic group required to form a cycloalkyl group together with a carbon atom.

R ₁₂ to R ₁₄ each independently represent an alkyl group or a cycloalkyl group, provided that at least one of R ₁₂ to R ₁₄ is a cycloalkyl group.

R ₁₅ and R ₁₆ each independently represent an alkyl group or a cycloalkyl group, provided that at least one of R ₁₅ and R ₁₆ is a cycloalkyl group.

R ₁₇ to R ₂₁ each independently represent a hydrogen atom or an alkyl group or a cycloalkyl group, provided that at least one of R ₁₇ to R ₂₁ is a cycloalkyl group and one of R ₁₉ and R ₂₁ is an alkyl group or a cycloalkyl group.

R ₂₂ to R ₂₅ each independently represent a hydrogen atom or an alkyl group or a cycloalkyl group, provided that at least one of R ₂₂ to R ₂₅ is a cycloalkyl group and R ₂₃ and R ₂₄ may be bonded together to form a ring.

In the formula (II-AB), R ₁₁ ' and R ₁₂ ' each independently represent a hydrogen atom, a cyano group, a halogen atom, or an alkyl group.

Z' represents an atomic group containing two carbon atoms (C-C) bonded together in an alicyclic structure.

More preferably, the above formula (II-AB) is represented by the following formula (II-AB1) or the following formula (II-AB2).

In the general formulae (II-AB1) and (II-AB2), R ₁₃ ' to R ₁₆ ' each independently represent a hydrogen atom, a halogen atom, a cyano group, -COOH, -COOR ₅ , and a group decomposed by the action of an acid. , -C(=O), -X-A'-R ₁₇ ', alkyl, or cycloalkyl, provided that at least two of R ₁₃ ' to R ₁₆ ' may be bonded together to form a ring.

R ₅ above represents an alkyl group, a cycloalkyl group, or a group having a lactone structure.

X represents an oxygen, _{sulfur, -NH -, - NHSO 2 -} , or -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 formulae (pI) to (pV), the alkyl group represented by R ₁₂ 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, a n-propyl group, Isopropyl, n-butyl, isobutyl, and second butyl.

The cycloalkyl group of R ₁₂ to R ₂₅ or the cycloalkyl group formed by Z and a carbon atom may be monocyclic or polycyclic. A specified example thereof includes a group having 5 or more carbon atoms and having a monocyclic, bicyclic, tricyclic or tetracyclic structure. These cycloalkyl groups preferably have from 6 to 30, particularly preferably from 7 to 25 carbon atoms. These cycloalkyl groups may have a substituent.

Preferable examples of the cycloalkyl group include an adamantyl group, adamantyl group, a decahydronaphthalene residue, a tricyclodecanyl group, a tetracyclododecyl group, a decyl group, a cedar group, a cyclopentyl group, a cyclohexyl group, Cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl. More preferred examples thereof include adamantyl, norbornyl, cyclohexyl, cyclopentyl, tetracyclododecyl, and tricyclic fluorenyl.

These alkyl groups and cycloalkyl groups may further have a substituent. Examples of the substituent of the alkyl group and the cycloalkyl group include an alkyl group (having 1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (having 1 to 4 carbon atoms), a carboxyl group, and an alkoxycarbonyl group ( Has 2 to 6 carbon atoms). Examples of the substituent which may be attached to the above alkyl group, alkoxy group and alkoxycarbonyl group include a hydroxyl group, a halogen atom and an alkoxy group.

The structure represented by the general formula (pI) to (pV) can be used to protect an alkali-soluble group. Examples of alkali soluble groups include various groups well known in the art.

More specifically, it has 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 one of the formulae (pI) to (pV). Preferred examples thereof include a hydrogen atom in a carboxylic acid group or a sulfonic acid group. A structure substituted by a structure represented by one of the general formulae (pI) to (pV).

As the repeating unit having an alkali-soluble group protected by the structure represented by one of the general formulae (pI) to (pV), it is preferably a repeating unit represented by the following formula (pA).

In the formula (pA), R represents a hydrogen atom, a halogen atom or an alkyl group (preferably having 1 to 4 carbon atoms). The plurality of Rs may be the same or different from each other.

A represents a single bond or one or more selected from the group consisting of alkylene, ether, thioether, carbonyl, ester, decylamine, sulfonamide, urethane, and ureido groups, and combinations thereof. A is preferably a single bond.

R _p1 represents a group represented by the above formula (pI) to (pV).

It is particularly preferred that the repeating unit represented by the formula (pA) is a repeat comprising 2-alkyl-2-adamantyl (meth)acrylate or dialkyl (1-adamantyl)methyl (meth)acrylate unit.

Next, a specific example of the repeating unit represented by the general formula (pA) will be described, although the invention is not limited thereto.

In the following formula, R _x represents H, CH ₃ or CH ₂ OH; and R _xa and R _xb each represent an alkyl group having 1 to 4 carbon atoms.

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

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

The atomic group Z' used to form the alicyclic structure is an atomic group which forms a repeating unit of an alicyclic hydrocarbon which may have a substituent in the resin. In particular, it is preferably an atomic group for forming a crosslinked alicyclic structure which forms a crosslinked alicyclic hydrocarbon repeating unit.

Examples of the skeleton of the aliphatic cyclic hydrocarbon thus formed comprises the general formula (the pI) to (the pV) the same as the R ₁₂ to R ₂₅ represents an alicyclic hydrocarbon group of persons.

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

In the alicyclic hydrocarbon-based acid-decomposable resin according to the present invention, the acid-decomposable group may have at least one repeating unit selected from the group consisting of having an alicyclic ring represented by one of the above formulas (pI) to (pV) a repeating unit of a partial structure of a hydrocarbon, a repeating unit represented by the formula (II-AB), and a repeating unit of a copolymerizable component described later. Preferably, the acid-decomposable group is contained in a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by one of the above formulas (pI) to (pV).

The above general formula (II-AB1) or (II-AB2) in R ₁₃ 'to R _16' may be used as the substituent of the above general formula (II-AB) atomic group for forming a ring structure of the aliphatic or for forming A substituent of the atomic group Z' of the crosslinked alicyclic structure.

Next, a specific example of a repeating unit represented by the above formula (II-AB1) or (II-AB2) will be described, and the present invention is not limited by these specific examples.

It is preferred that the alicyclic hydrocarbon-based acid-decomposable resin according to the present invention has a repeating unit having a lactone group. As the lactone group, any group can be used as long as it has a lactone structure. It is preferably a group having a 5- to 7-membered lactone ring structure, and is still preferably a group in which the other ring structure is fused with a 5- to 7-membered lactone ring structure to form a bicyclic structure or a helical structure. More preferably, the alicyclic hydrocarbon-based acid-decomposable resin according to the present invention has a repeating unit having a lactone structure represented by any one of the following general formulae (LC1-1) to (LC1-16). The group having a lactone structure can be directly attached to the main chain. Preferred lactone structures include (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), and (LC1-14). By using the specified lactone structure, it can improve line edge roughness and development.

The lactone ring structure may or may not have a substituent (Rb ₂ ). Preferred examples of the substituent (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), an alkoxycarbonyl group (preferably having 1 to 8 carbon atoms), a carboxyl group, a halogen atom, a hydroxyl group, a cyano group, an acid decomposable group or the like. n ₂ represents an integer of 0 to 4. In the case where n ₂ is an integer of 2 or more, a plurality of Rb ₂ may be the same or different. Further, a plurality of Rb ₂ may be bonded together to form a ring.

Examples of the repeating unit having a lactone structure including any one of the formulae (LC1-1) to (LC1-16) include R ₁₃ ' to R in the above formula (II-AB1) or (II-AB2) At least one of ₁₆ ' has a group represented by one of the formulae (LC1-1) to (LC1-16) (for example, wherein R _{5 in} -COOR ₅ is from the formula (LC1-1) to (LC1-16) The repeating unit represented by one of the groups, the repeating unit represented by the following general formula (AI), and the like.

In the general formula (AI), Rb ₀ represents a hydrogen atom, a halogen atom or an alkyl group (preferably having 1 to 4 carbon atoms).

As the substituent which the alkyl group Rb ₀ may have, it may be a hydroxyl group and a halogen atom.

Examples of the halogen atom 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, a carboxyl group, or a divalent group including a combination thereof. It is preferably a single bond or a linking group represented by -Ab ₁ -CO ₂ -. Ab ₁ represents a linear or branched alkyl group or a monocyclic or polycyclic cycloalkyl group, and preferred examples thereof include a methylene group, an exoethyl group, a cyclohexyl group, an adamantyl group, and an extended fluorenyl group.

V represents a group having a lactone structure represented by any one of the formulae (LC1-1) to (LC1-16).

The repeating unit having a lactone structure is usually produced as an optical isomer, and any optical isomer can be used. Further, any optical isomer or a mixture of optical isomers may be used. In the case where a single single optical isomer is used, its optical purity (ee) is preferably 90 or more, more preferably 95 or more.

Next, a specified example of a repeating unit having a lactone structure is proposed, although the invention is not limited thereto.

In the following formula, R _x represents H, CH ₃ , CH ₂ OH, or CF ₃ .

In the following formula, R _x represents H, CH ₃ , CH ₂ OH, or CF ₃ .

In the following formula, R _x represents H, CH ₃ , CH ₂ OH, or CF ₃ .

In addition to the above-described hydroxyl group-containing alicyclic hydrocarbon group in the repeating unit represented by the formula (NHG-1), the alicyclic hydrocarbon-based acid-decomposable resin according to the present invention preferably has a repeating unit having an organic group having a polar group. In particular, a repeating unit having a polar group-substituted alicyclic hydrocarbon structure. This can further improve the substrate adhesion. Preferable examples of the alicyclic hydrocarbon structure in which the alicyclic hydrocarbon structure is substituted by a polar group include an adamantyl group, a diadamantyl group and a norbornyl group. Preferred examples of the polar group include a carboxyl group and a cyano group.

Preferable examples of the polar group-substituted alicyclic hydrocarbon structure include a partial structure represented by the following general formulae (VIIa) to (VIId).

In the general formulae (VIIa) to (VIIc), R _2c to R _4c each independently represent a hydrogen atom, a hydroxyl group or a cyano group, provided that at least one of R _2c to R _4c represents a carboxyl group or a cyano group. It is preferred that one or two of R _2c to R _4c are a hydroxyl group, and the rest represent a hydrogen atom.

More preferably, in the formula (VIIa), two of R _2c to R _4c are a cyano group, and the balance is a hydrogen atom.

Examples of the repeating unit having a group represented by any one of the general formulae (VIIa) to (VIId) include wherein at least one of R ₁₃ ' to R ₁₆ ' in the above formula (II-AB1) or (II-AB2) has a repeating unit represented by any one of the formulae (VIIa) to (VIId) (for example, wherein R _{5 in} -COOR ₅ is a group represented by any one of the formulae (VIIa) to (VIId)), or a formula Repeating units represented by (AII-a) to (AII-d).

In the general formulae (AII-a) to (AII-d), R _1c represents a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group. R _2c to R _4c have the general formula (Vila) to (VIId) in the same meaning of R _2c to R _4c.

Next, a designation example of a repeating unit having a structure represented by any one of the general formulae (AII-a) to (AII-d) is shown, although the invention is not limited thereto.

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

In the formula (VIII), Z ₂ represents -O- or -N(R ₄₁ )-, wherein R ₄₁ represents a hydrogen atom, a hydroxyl group, an alkyl group, or -OSO ₂ -R ₄₂ , wherein R ₄₂ represents an alkyl group, A cycloalkyl or camphor residue. Alkyl R ₄₁ and R ₄₂ may be further (preferably fluorine atom) substituted with a halogen atom.

Next, a specific example of the repeating unit represented by the general formula (VIII) is proposed, although the invention is not limited thereto.

Preferably, the alicyclic hydrocarbon-based acid-decomposable resin according to the present invention has a repeating unit having an alkali-soluble group, more preferably a repeating unit having a carboxyl group. Due to the presence of this repeating unit, it improves the resolution when used for contact holes. Preferred examples of the repeating unit having a carboxyl group include any of which a carboxyl group directly attached to a repeating unit of a resin main chain (such as a main repeating unit of acrylic acid or methacrylic acid), a repeating unit in which a carboxyl group is attached to a resin main chain via a linking group, and a polymerization initiator or a chain transfer agent having an alkali-soluble group The alkali soluble group is introduced into the repeating unit of the terminal of the polymer chain during the polymerization. The linking group may have a monocyclic or polycyclic alicyclic hydrocarbon structure. It is particularly preferably a repeating unit comprising acrylic acid or methacrylic acid.

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

In the formula (F1), R ₅₀ to R ₅₅ each independently represent a hydrogen atom, a fluorine atom or an alkyl group, provided that at least one of R ₅₀ to R ₅₅ represents a fluorine atom, or at least one hydrogen atom thereof passes through a fluorine atom. Substituted alkyl.

R _xa represents a hydrogen atom or an organic group (preferably an acid-decomposable protecting group, an alkyl group, a cycloalkyl group, a decyl group, an alkoxycarbonyl group, an alkoxycarbonylmethyl group, an alkoxymethyl group, or a 1-alkane group). Oxyethyl).

The alkyl groups R ₅₀ to R ₅₅ may be substituted by a halogen atom such as a fluorine atom, a cyano group or the like. Preferred examples thereof include an alkyl group having 1 to 3 carbon atoms such as a methyl group and a trifluoromethyl group.

Preferably, R ₅₀ to R ₅₅ are each a fluorine atom.

Preferable examples of the organic group represented by R _xa include an acid-decomposable protecting group, an optionally substituted alkyl group, a cycloalkyl group, a decyl group, an alkoxycarbonyl group, an alkoxycarbonylmethyl group, an alkoxymethyl group. And 1-alkoxyethyl.

As a preferred example of the repeating unit having a group represented by the formula (F1), a repeating unit represented by the following formula (F2) can be listed.

In the formula (F2), R _x represents a hydrogen atom, a halogen atom or an alkyl group (preferably having 1 to 4 carbon atoms). As a preferred example of the substituent which the alkyl group R _x may carry, it may list a hydroxyl group and a halogen atom.

F _a represents a single bond or a linear or branched alkyl group, and is preferably a single bond.

F _b represents a monocyclic or polycyclic hydrocarbon group.

F _c represents a single bond or a linear or branched alkyl group, and is preferably a single bond or a methylene group.

F ₁ represents a group represented by the formula (F1).

p ₁ represents 1 to 3.

As for the cyclic hydrocarbon group in F _b , it is preferably a cyclopentyl group, a cyclohexyl group and a norbornyl group.

Next, a designation example of a repeating unit having a structure represented by the general formula (F1) is proposed, and the present invention is not limited thereto.

The alicyclic hydrocarbon-based acid-decomposable resin according to the present invention may further have a repeating unit having an alicyclic hydrocarbon structure but exhibiting no acid decomposition power. This prevents the low molecular weight component from being eluted from the photoresist film into the immersion liquid during the immersion exposure. Examples of the repeating unit include repeating units containing 1-adamantyl (meth)acrylate, tricyclodecyl (meth)acrylate, cyclohexyl (meth)acrylate, and the like.

In addition to the above repeating structural units, in order to control dry etching resistance, standard developer suitability, substrate adhesion, photoresist profile, and other characteristics typically required for photoresist (eg, resolution, heat resistance, and sensitivity), in accordance with the present invention The alicyclic hydrocarbon-based acid-decomposable resin may have various repeating structural units.

Examples of such repeating structural units include repeating structural units corresponding to the following monomers. However, the invention is not limited thereto.

Thus, the properties required for the alicyclic hydrocarbon-based acid-decomposable resin can be precisely controlled, particularly the following.

(1) Solubility in a coating solvent.

(2) Film formation properties (glass transition point).

(3) Solubility in positive developer and negative developer.

(4) Membrane loss (selection of hydrophilic/hydrophobic and alkali-soluble groups).

(5) Adhesion of the unexposed portion to the substrate.

(6) Dry etching resistance and the like.

Examples of the monomer include a compound having an addition polymerizable unsaturated bond selected from the group consisting of acrylate, methacrylate, acrylamide, methacrylamide, allyl compound, vinyl ether, vinyl ester Wait.

Further, the monomer having various repeating structural units listed above may copolymerize an addition polymerizable unsaturated compound as long as it can be copolymerized with a monomer.

In the alicyclic hydrocarbon-based acid-decomposable resin, the molar ratio of each repeating structural unit can be appropriately determined to control the dry etching resistance of the photoresist, the standard developer suitability, the photoresist adhesion, the photoresist profile, and Other properties (such as resolution, heat resistance, and sensitivity) are typically required for photoresist.

Preferred examples of the film form of the alicyclic hydrocarbon-based acid-decomposable resin according to the present invention are as follows.

(1) an alicyclic hydrocarbon containing a repeating unit represented by the formula (NGH-1) and a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by one of the above formulas (pI) to (pV) The main acid-decomposable resin (side chain type) is preferably a (meth) acrylate repeating unit having a structure of one of (pI) to (pV).

(2) A repeating unit represented by the formula (NGH-1) and a repeating unit represented by the formula (II-AB) (main chain type), and examples of the condition (2) include the following.

(3) having a repeating unit represented by the formula (NGH-1), a repeating unit represented by the formula (II-AB), a maleic anhydride derivative structure, and a (meth) acrylate structure ( Hybrid).

In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having an acid-decomposable group is preferably from 10 to 60 mol%, more preferably from 20 to 50 mol%, and more preferably from all repeating units. 25 to 40% by mole.

In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having a partial structure containing an alicyclic hydrocarbon represented by one of the general formulae (pI) to (pV) is preferably 20 to 70 moles based on the total repeating unit. The ear %, more preferably 20 to 50 mol%, and more preferably 25 to 40 mol%.

In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having a repeating unit represented by the formula (II-AB) is preferably from 10 to 60 mol%, more preferably from 15 to 55, based on the total repeating unit. Molar%, and more preferably 20 to 50 mol%.

In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having a lactone structure is preferably from 10 to 70 mol%, more preferably from 20 to 60 mol%, and still more preferably 25, based on the total repeating unit. Up to 40% by mole.

In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit represented by the formula (NHG-1) is preferably from 1 to 15 mol%, and more preferably from 5 to 15 mol%.

In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having a polar group other than the polar group contained in the formula (NHG-1) is preferably from 1 to 30 mol% based on the total repeating unit, more preferably 1 to 20 mol%, and more preferably 5 to 15 mol%.

Although the content of the repeating unit in terms of the monomer as the above-mentioned additional copolymerization component in the resin can be appropriately determined depending on the desired photoresist property, it is usually preferred that the content is a repeating unit represented by the general formula (NHG-1). Have the above More preferably, the repeating unit of the partial structure of the alicyclic hydrocarbon represented by one of the formulas (pI) to (pV) and the molar unit of the repeating unit represented by the above formula (II-AB) are not more than 99 mol%, more preferably It is not more than 90% by mole, and more preferably not more than 80% by mole.

In the case where the composition of the present invention is used for ArF exposure, it is preferred that the resin has no aromatic group from the viewpoint of transparency to the ArF light beam.

As the alicyclic hydrocarbon to be used as the acid-decomposable resin of the present invention, it is preferred that all of the repeating units are composed of repeating units of (meth) acrylate. In this case, it is possible to use any one in which all of the repeating units are composed of acrylate repeating units, in which all of the repeating units are composed of methacrylic repeating units, and all of the repeating units are composed of acrylate/(methyl) The acrylate mixture composition is preferably used in which the content of the acrylate repeating unit is 50 mol% or less based on the total repeating unit.

The alicyclic hydrocarbon-based acid-decomposable resin is preferably a (meth) acrylate having a repeating unit represented by the formula (NHG-1), a (meth) acrylate having a lactone ring, and an acid-decomposable group. The (meth) acrylate is a copolymer of the main repeating unit.

The alicyclic hydrocarbon-based acid-decomposable resin is still preferably a repeating unit represented by the formula (NHG-1) in an amount of 1 to 15 mol%, and 20 to 50 mol% of the formula (pI) a repeating unit of a partial structure of an alicyclic hydrocarbon represented by one of (pV), and a copolymer of 20 to 50 mol% of a repeating unit having a lactone structure, or a further repeat containing 0 to 20 mol% Copolymer of the unit.

Particularly preferred examples of the resin include a repeating unit having 20 to 50 mol% of an acid-decomposable group represented by one of the following general formulae (ARA-1) to (ARA-7), 20 to 50 mol% A repeating unit having a lactone structure represented by one of the following general formulae (ARL-1) to (ARL-6), and 1 to 15 mol% of having a formula (ARH-1) to (ARH-2) One of which represents a terpolymer of a repeating unit of a polar group-substituted alicyclic hydrocarbon structure, and a repeating unit further having 5 to 20 mol% of a carboxyl group, or represented by the formula (F1) and not shown A tetrapolymer of an alicyclic repeating unit of acid decomposition.

(In the formula below, R _xy1 represents a hydrogen atom or a methyl group; R _xa1 and R _xb1 each independently represent a methyl group or an ethyl group; and R _xc1 represents a hydrogen atom or a methyl group).

The alicyclic hydrocarbon used in the present invention is a main acid decomposable resin which can be synthesized in accordance with a usual method (e.g., radical polymerization). Examples of commonly used synthetic methods include an integral polymerization method comprising dissolving a monomer species and an initiator in a solvent and heating to thereby polymerize, and a method comprising dropping a solution of the monomer species and the initiator into the heated solvent over 1 to 10 hours. Into the polymerization method, etc. It is preferably a dropping polymerization method. Examples of the reaction solvent include tetrahydrofuran, 1,4-dioxane, ether (e.g., diisopropyl ether), ketone (e.g., methyl ethyl ketone and methyl isobutyl ketone), an ester solvent (e.g., ethyl acetate), and a decylamine solvent ( Such as dimethylformamide and diethylformamide), and as discussed below, soluble in the composition according to the invention Solvent (eg propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether and cyclohexanone). More preferably, the same solvent as used in the photoresist composition according to the present invention is used so that the occurrence of particles can be prevented during storage.

It is preferably polymerized in an inert atmosphere such as nitrogen or argon. As the polymerization initiator, polymerization is initiated using a commercially available radical initiator (azo-type initiator, peroxide, etc.). As the radical initiator, an azo type initiator is preferred. An azo type initiator having an ester group, a cyano group or a carboxyl group is preferred. Preferable examples of the initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, 2,2'-azobis(2-methylpropionic acid) dimethyl ester, and the like. The initiator is additionally used or added in portions if necessary. The initiator can then be added to the solvent after the reaction has ended, thus collecting the desired polymer as a powder or solid. The reaction concentration is 5 to 50% by mass, preferably 10 to 30% by mass. The reaction temperature is usually from 10 ° C to 150 ° C, preferably from 30 ° C to 120 ° C, and more preferably from 60 ° C to 100 ° C.

Purification can be carried out in the same manner as in the case of the resin (D) described later. For example, it may be washed with water, including a liquid-liquid extraction method in which a suitable solvent is combined and thus the residual monomer and oligomer components are removed, including ultrafiltration to extract and remove a solution state filtration method having a specified molecular weight or less. The method includes a reprecipitation method of dropping a resin solution into a poor solvent, curing the resin in the poor solvent, separating the residual monomers, and the like, and a solid-state purification method including filtering the resin slurry and washing with a poor solvent.

The weight average molecular weight of the resin (A) according to the present invention is preferably from 1,000 to 200,000, more preferably from 1,000 to 20,000, and particularly preferably from 1,000 to 15,000, in terms of polystyrene by the GPC method. By dividing the weight evenly The adjustment of the sub-quantity to 1,000 to 200,000 can prevent deterioration of heat resistance or dry etching resistance while preventing deterioration of development properties due to an increase in viscosity and degradation of film formation properties.

In another embodiment, the weight average molecular weight of the resin (A) according to the present invention is preferably from 3,000 to 95,000 in terms of polystyrene by the GPC method. By adjusting the weight average molecular weight to 3,000 to 95,000, formation of a photoresist residue (hereinafter also referred to as "scum") can be prevented, so that an improved pattern can be formed.

It is preferably a resin having a degree of dispersion (molecular weight distribution) of usually 1 to 5, preferably 1 to 3, more preferably 1.2 to 3.0, and particularly preferably 1.2 to 2.0. A less dispersed resin produces better resolution, photoresist profile, smoothness of the sidewalls of the photoresist pattern, and roughness.

In the photoresist composition according to the present invention, the content of the resin in accordance with the present invention in all the compositions is preferably from 50 to 99.99% by mass, more preferably from 60 to 99.0% by mass, based on the total solids.

The present invention may use a single resin or two or more resins.

From the viewpoint of compatibility with the resin (D), it is preferred that the alicyclic hydrocarbon is a main acid-decomposable resin free from fluorine and ruthenium atoms.

(B) Compounds which produce acid when irradiated with actinic radiation or radiation

The photoresist composition according to the present invention contains a compound which can generate an acid upon irradiation with actinic rays or radiation (hereinafter also referred to as "photoacid generator" or "ingredient (B)").

As the photoacid generator, a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization, a photodecolorizer for dyes, a photochromic agent, and the like can be suitably used. Known compounds which produce an acid upon irradiation with actinic radiation or radiation, such as micro-resistances, and mixtures thereof.

For example, it may be listed as a diazonium salt, a phosphonium salt, a phosphonium salt, a phosphonium salt, a sulfonium imide sulfonate, an anthracene sulfonate, a diazodiazine, a diterpene, an o-nitrobenzylsulfonate or the like.

Further, a compound in which a group or a compound which can generate an acid upon irradiation with actinic rays or radiation is introduced into a main chain or a side chain of the polymer can be used, for example, U.S. Patent No. 3,849,137, German Patent No. 3,914,407, JP-A -63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, JP-A-63 The compound described in the '146 patent.

Further, a compound which generates an acid by the action of light, which is described in, for example, U.S. Patent No. 3,779,778 and European Patent No. 126,712, can also be used.

As preferred compounds of the compound which can generate an acid upon irradiation with actinic rays or radiation, compounds represented by the following general formulae (ZI), (ZII) and (ZIII) can be used.

In the general formula (ZI), R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represent an organic group.

X ^- represents a non-nucleophilic anion, which is preferably a sulfonic acid anion, a carboxylic acid anion, an anthracene (alkylsulfonyl) decyl anion, a sulfhydryl methine anion, BF ^4- , PF ^6- , SbF ^6-, etc. are exemplified. An organic anion having a carbon atom is preferred.

As preferred examples of the organic anion, the following can be listed.

In the above formula, R _c1 represents an organic group.

As the organic group R _c1 , it may be listed as having 1 to 30 carbon atoms. Preferred examples thereof include optionally substituted alkyl groups, aryl groups, and a plurality of these groups via a single bond or a linking group (e.g., -O-, -CO ₂ -, -S-, -SO ₃ -, -SO ₂ N(R _d1 ) _-etc. ). R _d1 represents a hydrogen atom or an alkyl group.

R _c3 , R _c4 and R _c5 each independently represent an organic group. With _regard to preferred examples of the organic groups R _c3 , R _c4 and R _c5 , those listed as preferred examples of R _c1 above may be listed. Particularly preferred is a perfluoroalkylene group having 1 to 4 carbon atoms.

R _c3 and R _c4 may be bonded together to form a ring. Examples of the ring formed by bonding R _c3 and R _c4 together include an alkylene group and an extended aryl group. Preferred is a perfluoroalkylene group having 1 to 4 carbon atoms.

_Particularly preferred examples of the organic group R _c1 and R _c3 to R _c5 include an alkyl group substituted with a fluorine atom or a fluoroalkyl group at the 1-position, and a phenyl group substituted with a fluorine atom or a fluoroalkyl group. Due to the presence of a fluorine atom or a fluoroalkyl group, the acidity of the acid due to light irradiation increases and the sensitivity is thus increased. When R _c3 and R _{c4 are} bonded together to form a ring, the acidity of the acid due to light irradiation increases and the sensitivity is thus increased.

The organic group each represented by R ₂₀₁ , R ₂₀₂ and R ₂₀₃ usually has 1 to 30, preferably 1 to 20 carbon atoms.

R ₂₀₁ , R ₂₀₂ and R _{203 are} bonded together to form a ring structure which may contain an oxygen atom, a sulfur atom, an ester bond, a guanamine bond, or a carbonyl group in the ring. As examples of groups forming R _201, R ₂₀₂ and R ₂₀₃ bonded together of the two, which may be listed an alkylene group (e.g., stretch or elongation butyl pentyl).

Specific examples of the organic group represented by R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include the corresponding ones of the compounds (ZI-1), (ZI-2) and (ZI-3) described later.

A compound having a plurality of structures represented by the general formula (ZI) can also be used. For example, it may be a compound having a compound represented by the formula (ZI) wherein R ₂₀₁ , R ₂₀₂ and R _{203 are} bonded to each other, and another compound represented by the formula (ZI), R ₂₀₁ , R ₂₀₂ and R ₂₀₃ At least one of the structural compounds.

Still preferred examples of the compound (ZI) include the compounds (ZI-1), (ZI-2) and (ZI-3) described later.

The compound (ZI-1) is an arylsulfonium compound in which at least one of R ₂₀₁ , R ₂₀₂ and R ₂₀₃ in the above formula (ZI) is an aryl group, that is, a compound having an aryl hydrazine as a cation.

In the arylsulfonium compound, all of R ₂₀₁ , R ₂₀₂ and R ₂₀₃ may be an aryl group. Or a portion of R ₂₀₁ , R ₂₀₂ and R ₂₀₃ may be an aryl group, and the balance is an alkyl group or a cycloalkyl group.

Examples of the arylsulfonium compound include a triarylsulfonium compound, a diarylalkylsulfonium compound, an aryldialkylsulfonium compound, a diarylcycloalkylsulfonium compound, an arylbicycloalkylsulfonium compound, and the like.

As the aryl group in the arylsulfonium compound, it is preferably an aryl group (e.g., phenyl or naphthyl) and a heteroaryl group (e.g., an anthracene residue or a pyrrole residue). Still better Phenyl or anthracene residue. In the case where the aryl hydrazine compound has two or more aryl groups, these groups may be the same or different.

As the alkyl group (if necessary) of the aryl hydrazine compound, it is preferably a linear or branched alkyl group having 1 to 15 carbon atoms. Examples thereof include a methyl group, an ethyl group, a propyl group, a n-butyl group, a second butyl group, a tert-butyl group and the like.

As the cycloalkyl group which the aryl hydrazine compound carries, if necessary, it is preferably a cycloalkyl group having 3 to 15 carbon atoms. Examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclohexyl group and the like.

The aryl group, alkyl group or cycloalkyl group represented by R ₂₀₁ to R ₂₀₃ may have a substituent such as an alkyl group (for example, having 1 to 15 carbon atoms) or a cycloalkyl group (for example, having 3 to 15 carbon atoms) And an aryl group (for example, having 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. Preferable examples of the substituent include a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a linear or branched alkoxy group having 1 to 12 carbon atoms. Still preferred is an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms. This substituent may attach any or all of R ₂₀₁ to R ₂₀₃ . In the case where R ₂₀₁ to R ₂₀₃ are aryl groups, it is preferred that the substituents are attached to the opposite positions of the aryl groups.

Next, the compound (ZI-2) will be described.

The compound (ZI-2) is a compound in which R ₂₀₁ to R _{203 in} the formula (ZI) each independently represent an organic group having no aromatic ring. The term "aromatic ring" as used herein relates to an aromatic ring having a hetero atom.

The aromatic ring-free organic group represented by R ₂₀₁ to R ₂₀₃ usually has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.

R ₂₀₁ to R ₂₀₃ each independently preferably represent an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear, branched or cyclic 2-oxoalkyl group, or an alkoxycarbonylmethyl group, and More preferably, it is linear or branched 2-oxoalkyl.

The alkyl group represented by R ₂₀₁ to R ₂₀₃ may be a linear or branched alkyl group. Preferable examples thereof include a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, and pentyl group). As the alkyl group R ₂₀₁ to R ₂₀₃ , it is more preferably a linear or branched 2-oxoalkyl group or an alkoxycarbonylmethyl group.

Preferable examples of the cycloalkyl group represented by R ₂₀₁ to R ₂₀₃ include a cycloalkyl group having 3 to 10 carbon atoms (cyclopentyl group, cyclohexyl group and norbornyl group). As the cycloalkyl group R ₂₀₁ to R ₂₀₃ , it is more preferably a cyclic 2-oxoalkyl group.

Preferred examples of the linear, branched and cyclic 2-oxoalkyl group as R ₂₀₁ to R ₂₀₃ include the above-mentioned alkyl group and cycloalkyl group having a C=O attached to the 2-position thereof.

Preferable examples of the alkoxy group in the alkoxycarbonylmethyl group of R ₂₀₁ to R ₂₀₃ include an alkoxy group having 1 to 5 carbon atoms (methoxy group, ethoxy group, propoxy group, butoxy group). And pentyloxy).

R ₂₀₁ to R ₂₀₃ may further pass through a halogen atom, an alkoxy group (for example, 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 formula (ZI-3), that is, a compound having a phenylhydrazine sulfonium salt structure.

In the formula (ZI-3), R _1c to R _5c each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group or a halogen atom.

R _6c and R _7c each independently represent a hydrogen atom, an alkyl group or a cycloalkyl group.

R _x and R _y each independently represent an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group.

Any two or more of R _1c to R _7c may be bonded together and thus each form a ring structure. This ring structure contains an oxygen atom, a sulfur atom, an ester bond, or a guanamine bond. Examples of the ring formed by bonding any two or more of R _1c to R _7c together include a butyl group, a pentyl group and the like.

X ^- represents a non-nucleophilic anion which is identical to the non-nucleophilic anion X ^- in the formula (ZI).

The alkyl group represented by R _1c to R _7c may be linear or branched. Examples thereof include a linear or branched alkyl group having 1 to 20 carbon atoms, preferably a linear or branched alkyl group having 1 to 12 carbon atoms (e.g., methyl, ethyl, linear or branched propyl, linear or branched). Butyl, with linear or branched pentyl).

Preferable examples of the cycloalkyl group represented by R _1c to R _7c include a cycloalkyl group having 3 to 8 carbon atoms (e.g., a cyclopentyl group and a cyclohexyl group).

The alkoxy group represented by R _1c to R _5c may be linear, branched or cyclic. For example, it may list an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms (for example, a methoxy group, an ethoxy group, a linear group or a branched propoxy group). a linear or branched butoxy group, and a linear or branched pentyloxy group, and a cyclic alkoxy group having 3 to 8 carbon atoms (for example, a cyclopentyloxy group and a cyclohexyloxy group).

Preferably, any of R _1c to R _{5c is} a linear or branched alkyl group, a cycloalkyl group, or a linear, branched or cyclic alkoxy group. More preferably, the carbon atoms in R _1c to R _5c are from 2 to 15. This increases the solubility in the solvent and prevents particles from occurring during storage.

Examples of the alkyl group as R _x and R _y include the same as those listed above as R _1c to R _7c . The alkyl groups R _x and R _{y are more} preferably linear or branched 2-oxoalkyl or alkoxycarbonylmethyl.

Examples of the cycloalkyl group as R _x and R _y include the same as the cycloalkyl group listed above as R _1c to R _7c . The cycloalkyl groups R _x and R _{y are more} preferably a cyclic 2-oxoalkyl group.

Preferred examples of the linear, branched or cyclic 2-oxoalkyl group include the above-mentioned alkyl group or cycloalkyl group as R _1c to R _7c at the 2-position of >C=O.

Preferable examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as R _1c to R _5c as described above.

R _x and R _{y are} preferably an alkyl group having 4 or more carbon atoms, more preferably an alkyl group of 6 or more carbon atoms, and still more preferably an alkyl group having 8 or more carbon atoms.

In the above formulae (ZII) and (ZIII), R ₂₀₄ to R ₂₀₇ each independently represent an aryl group, an alkyl group or a cycloalkyl group.

Preferable examples of the aryl group represented by R ₂₀₄ to R ₂₀₇ include an aryl group such as a phenyl group or a naphthyl group. Still preferred is phenyl.

The alkyl group represented by R ₂₀₄ to R ₂₀₇ may be linear or branched. Preferable examples thereof include a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, and pentyl group).

Preferable examples of the cycloalkyl group represented by R ₂₀₄ to R ₂₀₇ include a cycloalkyl group having 3 to 10 carbon atoms (cyclopentyl group, cyclohexyl group and norbornyl group).

R ₂₀₄ to R ₂₀₇ may be substituted. Examples of the substituent which may be substituted by R ₂₀₄ to R ₂₀₇ include an alkyl group (for example, those having 1 to 15 carbon atoms), a cycloalkyl group (for example, having 3 to 15 carbon atoms), and an aryl group (for example, having 6). To 15 carbon atoms), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, and phenylthio groups.

X ^- represents a non-nucleophilic anion which is identical to the non-nucleophilic anion X ^- in the formula (ZI).

As preferred examples of the compound which can generate an acid upon irradiation with actinic rays or radiation, the compounds represented by the following general formulae (ZIV), (ZV) and (ZVI) can be further listed.

In the general formulae (ZIV) to (ZVI), Ar ₃ and Ar ₄ each independently represent an aryl group.

R ₂₂₆ represents an alkyl group or an aryl group.

R ₂₂₇ and R ₂₂₈ each independently represent an alkyl group, an aryl group or an electron attracting group.

R ₂₂₇ preferably represents an aryl group. R _{228 is} preferably an electron attracting group, and is still preferably a cyano group or a fluoroalkyl group.

A represents an alkyl group, an alkenyl group or an aryl group.

Still preferred examples of the compound which can generate an acid upon irradiation with actinic rays or radiation include compounds represented by the general formulae (ZI) to (ZIII).

The compound (B) is preferably one which can be irradiated with actinic rays or radiation. A compound which produces a fluorine-containing aliphatic sulfonic acid or a fluorine-containing benzenesulfonic acid.

The compound (B) preferably has a triphenylphosphonium structure.

The compound (B) is preferably a triphenylsulfonium salt compound having a fluoroalkyl group or a cycloalkyl group in the cationic portion.

This presents a preferred example of a compound which produces an acid upon irradiation with actinic radiation or radiation.

It may use a single photoacid generator or a combination of two or more thereof. In the case of using a combination of two or more thereof, it is preferred to combine a compound which can produce an atom other than two hydrogen atoms and an organic acid which differs by 2 or more.

The content of the photoacid generator is preferably from 0.1 to 20% by mass, more preferably from 0.5 to 10% by mass, and still more preferably from 1 to 7% by mass, based on the total solid matter in the photoresist composition.

(C) solvent

Examples of the solvent which can be used for dissolving the above components to prepare a photoresist composition include alkylene glycol monoalkyl ether carboxylate, alkylene glycol monoalkyl ether, alkyl lactate, alkyl alkoxypropionate, cyclic lactone. (preferably having 4 to 10 carbon atoms), a ring-containing monoketone compound (preferably having 4 to 10 carbon atoms), an alkylene carbonate, an alkyl alkoxyacetate, and an alkyl pyruvate .

Preferable 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, and propylene glycol monomethyl ether. Propionate, propylene glycol monoethyl ether propionate, ethylene glycol monomethyl ether acetate, and ethylene glycol monoethyl ether acetate.

Preferable 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.

Preferable examples of the alkyl lactate include methyl lactate, ethyl lactate, propyl lactate, and butyl lactate.

Preferable examples of the alkoxypropionic acid alkyl ester include ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, methyl 3-ethoxypropionate, and 3-methoxypropionic acid. Ethyl ester.

Preferable examples of the cyclic lactone include β-propiolactone, β-butyrolactone, γ-butyrolactone, α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, γ- Valerolactone, γ-caprolactone, γ-octanolactone, and α-hydroxy-γ-butyrolactone.

Preferable examples of the monoketone compound which may contain a ring include 2-butanone, 3-methylbutanone, tert-butyl ketone, 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-anthracene Ketone, 5-fluorenone, 2-nonanone, 3-fluorenone, 4-fluorenone, 5-hexen-2-one, 3-penten-2-one, cyclopentanone, 2-methylcyclopentan Ketone, 3-methylcyclopentanone, 2,2-dimethylcyclopentanone, 2,4,4-trimethylcyclopentanone, cyclohexanone, 3-methylcyclohexanone, 4-methyl Cyclohexanone, 4-ethylcyclohexanone, 2,2-dimethylcyclohexanone, 2,6-dimethylcyclohexanone, 2,2,6-trimethylcyclohexanone, cycloheptanone 2-methylcycloheptanone and 3-methylcycloheptanone.

Preferable examples of the alkylene carbonate include propylene carbonate, vinyl carbonate, ethyl carbonate, and butyl carbonate.

Preferable examples of the alkyl alkoxyacetate include ethyl 2-methoxyethyl ester, 2-ethoxyethyl acetate, 2-(2-ethoxyethoxy)ethyl acetate, and 3-methyl acetate. Oxy-3-methylbutyl ester, and 1-methoxy-2-propyl acetate.

Preferred examples of the alkyl pyruvate include methyl pyruvate and ethyl pyruvate. With propyl pyruvate.

It is preferably a solvent having a boiling point of 130 ° C or higher at room temperature under atmospheric pressure. Specific examples of the solvent include cyclopentanone, γ-butyrolactone, cyclohexanone, ethyl lactate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and ethyl 3-ethoxypropionate. Ethyl pyruvate, 2-ethoxyethyl acetate, 2-(2-ethoxyethoxy)ethyl acetate, and propyl carbonate.

In the present invention, one of these solvents may be used singly or two or more solvents may be used in combination.

As the organic solvent, a mixed solvent comprising a solvent having a hydroxyl group in the structure and a solvent having no hydroxyl group in the structure can be used in the present invention.

Examples of the hydroxyl group-containing solvent include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and ethyl lactate. Particularly preferred among these solvents are propylene glycol monomethyl ether and ethyl lactate.

Examples of the hydroxyl-free solvent include propylene glycol monomethyl ether acetate, ethoxyethyl propionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, N,N-dimethylacetamide, and dimethyl hydrazine. Particularly preferred among these solvents are propylene glycol monomethyl ether acetate, ethoxyethyl propionate, 2-heptanone, γ-butyrolactone, cyclohexanone, and butyl acetate, and still preferably propylene glycol-methyl Ether acetate, ethoxyethyl propionate and 2-heptanone.

The mixing ratio (mass ratio) of the hydroxyl group-containing solvent to the hydroxyl group-free solvent is from 1/99 to 99/1, preferably from 10/90 to 90/10, and more preferably from 20/80 to 60/40. From the viewpoint of coating uniformity, it is particularly preferably a mixed solvent containing 50% by mass or more of a hydroxyl group-free solvent.

The solvent is preferably two or more solvents containing propylene glycol monomethyl ether acetate Mixed solvent.

(D) a resin containing at least one of fluorine or antimony atoms

It is preferred that the photoresist composition according to the present invention contains at least one of fluorine- or hafnium-containing resins (D).

In the resin (D), fluorine or a halogen atom may be contained in the main chain of the resin or a side chain thereof.

The resin (D) is preferably a resin containing an alkyl group having a fluorine atom, a cycloalkyl group having a fluorine atom, or an aryl group having a fluorine atom as a fluorine atom-containing partial structure.

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. This group may have other substituents.

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. This group may have other substituents.

Examples of the aryl group having a fluorine atom include an aryl group in which at least one hydrogen atom is substituted with a fluorine atom, such as a phenyl group and a naphthyl group. This group may have other substituents.

Next, a specific example of an alkyl group having a fluorine atom, a cycloalkyl group having a fluorine atom, and an aryl group having a fluorine atom is proposed, although the invention is not limited thereto.

In the general formulae (F2a) to (F4a), R ₅₇ to R ₆₈ each independently represent a hydrogen atom, a fluorine atom or an alkyl group, provided that at least one of R ₅₇ to R _{61 and} at least one of R ₆₂ to R _{64 are present} . And at least one of R ₆₅ to R ₆₈ each represents a fluorine atom, or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom (preferably having 1 to 4 carbon atoms). Preferably, R ₅₇ to R ₆₁ and R ₆₅ to R ₆₇ are each a fluorine atom. Preferably, R ₆₂ to R ₆₄ and R _{68 are} each an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom (preferably having 1 to 4 carbon atoms), and more preferably has 1 to 4 carbon atoms. Perfluoroalkyl. R ₆₂ and R ₆₃ may be bonded to each other to form a ring.

Specific examples of the group represented by the formula (F2a) include p-fluorophenyl group, pentafluorophenyl group and 3,5-bis(trifluoromethyl)phenyl group.

Specific examples of the group represented by the formula (F3a) include trifluoroethyl, pentafluoropropyl, pentafluoroethyl, heptafluorobutyl, hexafluoroisopropyl, heptafluoroisopropyl, hexafluoro (2- Methyl)isopropyl, nonafluorobutyl, octafluoroisobutyl, nonafluorohexyl, nonafluorobutanyl, perfluoroisopentyl, perfluorooctyl, perfluoro(trimethyl)hexyl, 2 , 2,3,3-tetrafluorocyclobutyl, perfluorocyclohexyl, and the like. More preferred examples are hexafluoroisopropyl, heptafluoroisopropyl, hexafluoro(2-methyl)isopropyl, octafluoroisobutyl, nonafluoro-t-butyl, and perfluoroisopentyl. Also better for six Fluoroisopropyl or heptafluoroisopropyl.

Specific examples of the group represented by the formula (F4a) include -C(CF ₃ ) ₂ OH, -C(C ₂ F ₅ ) ₂ OH, -C(CF ₃ )(CH ₃ )OH, -CH(CF _{3 )} ) OH and so on. Preferred is -C(CF ₃ ) ₂ OH.

As for the fluorene-containing partial structure, it is preferred that the resin (D) has an alkyl fluorenyl group structure (preferably a trialkyl decyl group) or a cyclic oxime structure.

Specific examples of the alkyl fluorenyl structure or the cyclic siloxane structure include those represented by the following general formulae (CS-1) to (CS-3).

In the general formulae (CS-1) to (CS-3), R ₁₂ to R ₂₆ each independently represent a linear or branched alkyl group (preferably having 1 to 20 carbon atoms) or a cycloalkyl group (preferably Has 3 to 20 carbon atoms).

L ₃ to L ₅ each represent a single bond or a divalent linking group. Examples of the divalent linking group include a member selected from an alkyl group, a phenyl group, an ether group, a thioether group, a carbonyl group, an ester group, a decylamino group, a urethane group, and a urea group, or a di- or More combinations.

n represents an integer from 1 to 5.

As an example of the resin (D), it may list a resin having at least one repeating unit selected from the repeating units represented by the following general formulae (C-I) to (C-V).

In the general formulae (C-I) to (C-V), R ₁ to R ₃ each represent a hydrogen atom, an alkyl group (preferably having 1 to 4 carbon atoms), or a fluoroalkyl group (preferably having 1 to 4 carbon atoms).

W ₁ and W ₂ each independently represent an organic group having at least one of fluorine and a halogen atom.

R ₄ to R ₇ each independently represent a hydrogen atom, a fluorine atom, an alkyl group (preferably having 1 to 4 carbon atoms), or a fluoroalkyl group (preferably having 1 to 4 carbon atoms) under the condition that 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 be bonded to 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 fluoroalkyl group (preferably having 1 to 4 carbon atoms).

L ₁ and L ₂ each independently represent the same single bond or divalent linking group as L ₃ to L ₅ .

Q represents a monocyclic or polycyclic aliphatic group. That is, it represents an atomic group containing two carbon atoms (C-C) bonded to each other for forming an alicyclic structure.

R ₃₀ and R ₃₁ each independently represent a hydrogen atom or a fluorine atom.

R ₃₂ and R ₃₃ each independently represent an alkyl group, a cycloalkyl group, a fluoroalkyl group, or a fluorocycloalkyl group.

It should be noted that the repeating unit represented by the formula (C-V) 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 formula (C-I), and more preferably a repeating unit represented by any one of the following formulae (C-Ia) to (C-Id).

In the general formulae (C-Ia) to (C-Id), R ₁₀ and R ₁₁ each represent a hydrogen atom, an alkyl group (preferably having 1 to 4 carbon atoms), or a fluoroalkyl group (preferably having 1 to 4 carbon atoms).

W ₃ , W ₅ and W ₆ each represent an organic group having at least one of fluorine and a halogen atom.

W ₄ represents a fluorine atom or an organic group having at least one of fluorine and a halogen atom.

m represents an integer from 1 to 5.

n represents 0 or 1.

In the case where each of W ₁ to W ₆ is an organic group having at least one of fluorine and a halogen atom, a preferred example thereof is a linear or branched fluorinated alkyl group having 1 to 20 carbon atoms, or 1 to 20 carbons. A linear, branched or cyclic fluorinated alkyl ether group of atoms.

Examples of the fluoroalkyl group represented by W ₁ to W ₆ include trifluoroethyl, pentafluoropropyl, hexafluoroisopropyl, hexafluoro(2-methyl)isopropyl, heptafluorobutyl, hexafluoroiso Propyl, octafluoroisobutyl, nonafluorohexyl, nonafluorotributyl, perfluoroisopentyl, perfluorooctyl, perfluoro(trimethyl)hexyl, and the like.

When W ₁ to W ₆ each represent a ruthenium containing organic group, it is preferably an alkyl fluorenyl structure or a cyclic oxime structure. Specific examples of the alkyl fluorenyl structure include groups represented by the above general formulae (CS-1) to (CS-3).

Next, a specified example of a repeating unit represented by the general formula (C-I) in which X represents a hydrogen atom, -CH ₃ , -F, or -CF _{3 is} proposed.

The resin (D) is preferably a resin selected from the following (D-1) to (D-6).

(D-1) A resin comprising (a) a repeating unit having a fluoroalkyl group (preferably having 1 to 4 carbon atoms), more preferably a repeating unit (a).

(D-2) A repeating unit containing (b) a structure having a trialkylsulfanyl group or a cyclic fluorene oxide, more preferably a resin containing only repeating units.

(D-3) a repeating unit containing (a) having a fluoroalkyl group (preferably having 1 to 4 carbon atoms), and (c) having a branched alkyl group (preferably having 4 to 20 carbon atoms) a cycloalkyl group (preferably having 4 to 20 carbon atoms), a branched alkenyl group (preferably having 4 to 20 carbon atoms), a cycloalkenyl group (preferably having 4 to 20 carbon atoms), or A resin of a repeating unit of an aryl group (preferably having 4 to 20 carbon atoms) is more preferably a copolymer resin of the repeating unit (a) and the repeating unit (c).

(D-4) a repeating unit containing (b) a structure having a trialkylsulfanyl group or a cyclic oxime, and (c) having a branched alkyl group (preferably having 4 to 20 carbon atoms), a cycloalkyl group (preferably having 4 to 20 carbon atoms), branched alkenyl (preferably having 4 to 20 carbon atoms), cycloalkenyl (preferably having 4 to 20 carbon atoms), or aryl (comparative A resin which is preferably a repeating unit having 4 to 20 carbon atoms, more preferably a copolymer resin of the repeating unit (b) and the repeating unit (c).

(D-5) a repeating unit comprising (a) a repeating unit having a fluoroalkyl group (preferably having 1 to 4 carbon atoms), and (b) having a repeating unit having a trialkyldecyl group or a cyclic azide structure The resin is more preferably a copolymer resin of the repeating unit (a) and the repeating unit (b).

(D-6) one containing (a) having a fluoroalkyl group (preferably having 1 to 4 carbon atoms) a repeating unit of (b) a repeating unit having a trialkylalkylene group or a cyclic decane structure, and (c) having a branched alkyl group (preferably having 4 to 20 carbon atoms), a cycloalkyl group ( It preferably has 4 to 20 carbon atoms), a branched alkenyl group (preferably having 4 to 20 carbon atoms), a cycloalkenyl group (preferably having 4 to 20 carbon atoms), or an aryl group (preferably) The resin which is a repeating unit having 4 to 20 carbon atoms) is more preferably a copolymer resin of the repeating unit (a), the repeating unit (b) and the repeating unit (c).

Considering hydrophilicity/hydrophobicity, interaction, etc., the resin (D-3), (D-4), and (D-6) include a branched alkyl group, a cycloalkyl group, a branched alkenyl group, a cycloalkenyl group, or The repeating unit (c) of the aryl group may introduce a suitable functional group. From the viewpoint of the following force of the immersion liquid and the backward tilt contact angle, it is preferably a functional group having no polar group.

In the resins (D-3), (D-4) and (D-6), a repeating unit having a fluoroalkyl group (a) and/or a repeating unit having a trialkyldecyl or cyclic oxime structure ( The content of b) is preferably from 20 to 99 mol%.

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

In the 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 the formula (Ia), the alkyl group Rf in which at least one hydrogen atom is substituted by a fluorine atom is preferably an alkyl group having 1 to 3 carbon atoms, and more preferably a trifluoromethyl group.

The alkyl group of R ₁ is preferably a linear or branched alkyl group having 3 to 10 carbon atoms, more preferably a branched alkyl group having 3 to 10 carbon atoms.

The alkyl group of R ₂ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, and more preferably a linear or branched alkyl group having 3 to 10 carbon atoms.

Next, a specific example of the repeating unit represented by the general formula (Ia) is proposed, but the present invention is not limited thereto.

X represents F or CF ₃ .

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

In the 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 formula (I), Rf, R ₁ and R ₂ have the same meanings as Rf, R ₁ and R _{2 in} the formula (Ia).

As the compound represented by the general formula (I), commercially available products or synthetic compounds can be used. In the case of synthesizing a compound, it can be obtained by chlorinating 2-trifluoromethyl methacrylic acid to acid chloride and then esterifying the acid chloride.

The resin (D) having a repeating unit represented by the formula (Ia) preferably further contains a repeating unit represented by the following formula (III).

In the formula (III), R ₄ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a trialkylalkylene group, or a group having a cyclic oxime structure.

L ₆ represents a single bond or a divalent linking group.

In the formula (III), the alkyl group of 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 trialkylsulfanyl group is preferably a trialkylsulfonyl 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.

Next, a designation example of the resin (D) having a repeating unit represented by the general formula (Ia) is proposed, although the invention is not limited thereto.

The resin (D) is preferably a resin containing a repeating unit represented by the following formula (II) and a repeating unit represented by the following formula (III).

In the general formula (II) and the formula (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, or a cycloalkenyl group, or a group formed by bonding two or more of these groups.

R ₄ represents an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, a trialkylsulfanyl group, or a group having a cyclic siloxane structure, or a group formed by bonding two or more of these groups.

Each of the alkyl, cycloalkyl, alkenyl, cycloalkenyl, and trialkyldecyl groups of R ₃ and R ₄ may have a suitable functional group introduced therein. However, with respect to the following force of the immersion liquid, the functional group is preferably a non-polar group and more preferably unsubstituted.

L ₆ represents a single bond or a divalent linking group.

m and n each represent the molar ratio of the corresponding repeating unit, and the conditions are 0 < m < 100 and 0 < n < 100.

In the formula (II), Rf has the same meaning as Rf in the formula (I).

The alkyl group of 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 represents a single bond, a methylene group, an extended ethyl group, or an ether group.

It is preferably m from 30 to 70 and n from 30 to 70, more preferably from 40 to 60 and n from 40 to 60.

Next, a designation example of the resin (D) having a repeating unit represented by the general formula (II) and a repeating unit represented by the general formula (III) is proposed, but the present invention is not limited thereto.

The resin (D) may have a repeating unit represented by the following formula (VIII)

In the formula (VIII), Z ₂ represents -O- or -N(R ₄₁ )-, wherein R ₄₁ represents a hydrogen atom, 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 by a halogen atom (preferably a fluorine atom) or the like.

Preferably, the resin (D) is a solid at room temperature (25 ° C). Further, the glass transition temperature (Tg) thereof is preferably from 50 to 200 ° C, more preferably from 80 to 160 ° C.

A resin which is solid at 25 ° C means a melting point of 25 ° C or higher.

The glass transition temperature (Tg) can be measured by a scanning calorimeter (differential scanning calorimeter). For example, it can be determined by analyzing the change in volume ratio when the sample is heated again at 5 ° C / min after heating and then cooling the sample.

Preferably, the resin (D) is stable to acid and insoluble in an alkaline developer.

From the viewpoint of the following force of the immersion liquid, it is preferred that the resin (D) has no (x) alkali-soluble group, and (y) is decomposed by the action of a base (alkaline developing solution) to increase the solubility in the alkaline developing solution. And (z) a group which increases the solubility in the developer due to decomposition by the action of an acid.

In the resin (D), the total amount of the repeating unit having an alkali-soluble group or a group which increases the solubility in the developer due to the action of an acid or a base is preferably 20 mol% based on the total repeating unit of the constituent resin (D). Or less, more preferably 0 to 10 mol%, still more preferably 0 to 5 mol%.

Also unlike the surfactant which is generally used for photoresist, the resin (D) does not contain an ionic bond or a hydrophilic group such as (poly(oxyalkylene)). In the resin (D) contains pro In the case of a water-based polar group, the following force of the immersion liquid tends to decrease. It is therefore more preferred that the resin (D) does not have a polar group selected from the group consisting of a hydroxyl group, an alkanediol and a mercapto group. Further preferably, the resin (D) does not have an ether group which bonds a carbon atom of the main chain via a linking group, because the ether group causes an increase in hydrophilicity, thereby deteriorating the following force of the immersion liquid. On the other hand, it is preferably an ether group in which a carbon atom of the main chain is directly bonded in the above formula (C-Id) because the ether group sometimes exhibits activity as a hydrophobic group.

Examples of the (x) alkali-soluble group include a phenolic hydroxyl group, a carboxylic acid group, a fluoroalcohol group, a sulfonic acid group, a sulfonylamino group, a sulfonyl fluorenylene group, or an alkyl sulfonyl group. Methylene, (alkylsulfonyl) (alkylcarbonyl) fluorenylene, fluorenyl (alkylcarbonyl) methylene, fluorenyl (alkylcarbonyl) fluorenylene, fluorene (alkyl sulfonyl) a group such as a methylene group, an anthracene (alkylsulfonyl) quinone imine group, a ginseng (alkylcarbonyl) methylene group, a ginseng (alkylsulfonyl) methylene group or the like.

(y) Examples of the group which can be decomposed by the action of a base (alkaline developing solution) to increase the solubility in an alkaline developing solution include a lactone group, an ester group, a sulfonamide group, an acid anhydride, and a hydrazide group.

(z) Examples of the group which can be decomposed by the action of an acid to increase the solubility in the developer include the same group as the acid-decomposable group in the resin (A).

However, the repeating unit represented by the following general formula (pA-c) is not or hardly decomposed by the action of the acid as compared with the acid decomposable group of the resin (A), and thus it is considered that the non-acid is decomposable in the straight line.

In the formula (pA-c), R _p2 represents a hydrocarbon group having a tertiary carbon atom of an oxygen atom in the bonding formula.

In the case where the resin (D) contains a ruthenium atom, the ruthenium atom content is preferably from 2 to 50% by mass, more preferably from 2 to 30% by mass, based on the molecular weight of the resin (D). Further, the halogen atom-containing repeating unit is preferably from 10 to 100% by mass, more preferably from 20 to 100% by mass based on the resin (D).

In the case of the fluorine atom of the resin (D), the fluorine atom content is preferably from 5 to 80% by mass, more preferably from 10 to 80% by mass, based on the molecular weight of the resin (D).

Further, the fluorine atom-containing repeating unit is preferably from 10 to 100% by mass, and more preferably from 30 to 100% by mass, based on the resin (D).

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

The amount of the residual monomer in the resin (D) is preferably from 0 to 10% by mass, more preferably from 0 to 5% by mass, still more preferably from 0 to 1% by mass. Further, from the viewpoints of the resolution of the photoresist pattern, the shape of the photoresist, the side wall, the thickness, and the like, the molecular weight distribution (Mw/Mn, also referred to as the degree of dispersion) is preferably from 1 to 5, more preferably from 1 to 3, still more preferably. It is from 1 to 1.5.

The addition amount of the resin (D) in the photoresist composition is preferably from 0.1 to 20% by mass, more preferably from 0.1 to 10% by mass, based on the solid content of the photoresist composition. . Further, it is preferably from 0.1 to 5% by mass, more preferably from 0.2 to 3.0% by mass, and still more preferably from 0.3 to 2.0% by mass.

Similar to the resin (A), it is of course preferred that the resin (D) contains only a trace amount of impurities such as a metal. It is also preferred that the resin (D) contains a defined content or smaller residual monomer and oligomer component, for example, 0.1% by mass or less as determined by HPLC. This not only further improves the sensitivity, resolution, method stability, pattern shape, etc., as the photoresist, and the resulting photoresist also has no contaminants in the liquid or changes in sensitivity over time.

As the resin (D), a commercially available product can be used. Alternatively it can be synthesized according to conventional methods such as free radical polymerization. Examples of commonly used synthetic methods include an integral polymerization method comprising dissolving a monomer species and an initiator in a solvent and heating to thereby polymerize, and a method comprising dropping a solution of the monomer species and the initiator into the heated solvent over 1 to 10 hours. Into the polymerization method, etc. Examples of the reaction solvent include tetrahydrofuran, 1,4-dioxane, ether (e.g., diisopropyl ether), ketone (e.g., methyl ethyl ketone and methyl isobutyl ketone), an ester solvent (e.g., ethyl acetate), and a decylamine solvent ( For example, dimethylformamide and diethylformamide, and the solvents discussed below, which dissolve the composition according to the invention (e.g., propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether and cyclohexanone). More preferably, the same solvent as used in the photoresist composition according to the present invention is used so that the occurrence of particles can be prevented during storage.

It is preferably polymerized in an inert atmosphere such as nitrogen or argon. As the polymerization initiator, polymerization is initiated using a commercially available radical initiator (azo-type initiator, peroxide, etc.). As the radical initiator, an azo type initiator is preferred. Preferred is an azo type having an ester group, a cyano group or a carboxyl group. Initiator. Preferable examples of the initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, 2,2'-azobis(2-methylpropionic acid) dimethyl ester, and the like. Chain transfer agents can also be used if desired. The reaction concentration is 5 to 50% by mass, preferably 20 to 50% by mass, and more preferably 30 to 50% by mass. The reaction temperature is usually from 10 ° C to 150 ° C, preferably from 30 ° C to 120 ° C, and more preferably from 60 ° C to 100 ° C.

After the end of the reaction, it was allowed to stand and the reaction solution was cooled to room temperature and then purified. Purification can be accomplished using conventional methods, such as water washing, including liquid-liquid extraction methods that combine a suitable solvent and thus remove residual monomer and oligomer components, including ultrafiltration to extract and remove solutions having a specified molecular weight or smaller. The state filtration method includes a reprecipitation method in which a resin solution is dropped into a poor solvent, a resin in a poor solvent is solidified, and residual monomers are separated, and a solid purification method including filtering the resin slurry and washing it with a poor solvent. For example, the reaction solution is brought into contact with a volume of not more than 10 times (preferably 5 to 10 times by volume) of the solvent in which the above-mentioned resin is poorly soluble or insoluble (poor solvent), so that the resin precipitates into a solid.

The solvent (precipitation or reprecipitation solvent) used for precipitation or reprecipitation from the polymer solution may be any solvent as long as it is a poor solvent for the polymer. It may suitably be selected, for example, from hydrocarbons (for example, aliphatic hydrocarbons such as pentane, hexane, heptane, and octane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; aromatic hydrocarbons such as benzene, Toluene and xylene), halogenated hydrocarbons (eg halogenated aliphatic hydrocarbons such as dichloromethane, chloroform and carbon tetrachloride; halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene), nitro compounds (eg nitromethane and Nitroethane), nitrile (eg acetonitrile, benzonitrile), ether (eg chain ethers such as diethyl ether, diisopropyl ether, Dimethoxyethane; and a cyclic ether such as tetrahydrofuran and dioxane), a ketone (such as acetone, methyl ethyl ketone, diisobutyl ketone), an ester (such as ethyl acetate, butyl acetate), a carbonate (such as carbonic acid) Methyl ester, diethyl carbonate, ethyl carbonate, propyl carbonate), alcohol (such as methanol, ethanol, propanol, isopropanol, butanol), carboxylic acid (such as acetic acid), water, and the like Mixed solvent. The solvent for precipitation or reprecipitation is preferably a solvent containing at least an alcohol (particularly methanol or the like) or water. In the solvent containing at least a hydrocarbon, the ratio of the alcohol (particularly methanol or the like) to other solvents (for example, an ester such as ethyl acetate, and an ether such as tetrahydrofuran) is, for example, the former/the latter (volume ratio at 25 ° C). It is preferably from 10/90 to 99/1, preferably the former/the latter (volume ratio at 25 ° C) is from 30/70 to 98/2, more preferably the former/the latter (volume ratio at 25 ° C) is 50 /50 to 97/3.

The amount of the precipitation or reprecipitation solvent to be used can be appropriately selected in consideration of efficiency, productivity, and the like. It is usually used in an amount of 100 to 10,000 parts by mass, preferably 200 to 2,000 parts by mass, and more preferably 300 to 1,000 parts by mass per 100 parts by mass of the polymer solution.

In the step of feeding the polymer solution to a precipitation or reprecipitation solvent (poor solvent), the nozzle diameter is preferably 4 mm or less (for example, 0.2 to 4 mm), and the feed rate of the polymer solution to the poor solvent The (dropping rate) is, for example, 0.1 to 10 m/sec with respect to the linear velocity, and preferably about 0.3 to about 5 m/sec.

The precipitation or reprecipitation step is preferably carried out under agitation. Examples of agitating buckets that can be used for agitation include dish turbines, fan turbines (including paddles), curved bucket turbines, arrow feather turbines, Pfaudler type, strong type, and Angle wheel fan turbine, propeller, multi-section, anchor type (or horseshoe type), gate type, double belt type, and screw type. Preferably, the agitation is carried out for another 10 minutes or more, more preferably 20 minutes or more, after the end of the feed of the polymer solution. If the stirring time is too short, the monomer content in the polymer particles may not be sufficiently reduced in some cases. Further, mixing and stirring of the polymer solution and the poor solvent may be carried out using a linear mixer instead of the stirring blade.

While the temperature of precipitation or reprecipitation can be suitably selected in view of efficiency or performance, this temperature is usually from about 0 to about 50 ° C, preferably near room temperature (for example, from about 20 to about 35 ° C). The precipitation or reprecipitation step can be carried out according to any method using a conventional mixing vessel such as a stirred tank, such as a batch system and a continuous system.

The precipitated or reprecipitated particulate polymer is typically subjected to conventional solid-liquid separation, such as filtration and centrifugation, and then dried prior to use. The filtration system uses an anti-solvent filter material, preferably under high pressure. The drying is carried out at a temperature of from about 30 to about 100 ° C, preferably from about 30 to about 50 ° C, at atmospheric pressure or at a low pressure, preferably at a low pressure.

Once the resin is precipitated and separated, it can be dissolved again in the solvent and then contacted with a solvent in which the resin is poorly soluble or insoluble.

That is, the method may include, after the end of the radical polymerization reaction, precipitating the resin by contacting the polymer with a solvent in which the polymer is poorly soluble or insoluble (step a), separating the resin from the solution (step b), and re-dissolving the resin. The resin solution A is prepared in a solvent (step c) by bringing the resin solution A into contact with a resin in which the resin is poorly soluble or insoluble and the volume is less than 10 times (preferably 5 times or less by volume) of the resin solution A. Solvent, and separation of precipitation resin (step Step e), and the resin is precipitated.

As the solvent for preparing the resin solution A, the same solvent as the solvent for dissolving the monomer at the time of the polymerization reaction can be used, and the solvent can be the same as or different from the solvent used for the polymerization reaction.

(E) basic compound

Preferably, the photoresist composition according to the present invention contains (E) a basic compound, thereby alleviating the change in properties over time during exposure to heating.

As an example of the basic compound, a compound having a structure represented by the following formulas (A) to (E) can be listed.

In the general formulae (A) to (E), R ²⁰⁰ , R ²⁰¹ and R ²⁰² may be the same or different and each represents 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 (preferably having 6 to 20 carbon atoms). R ²⁰¹ and R ²⁰² may be bonded together to form a ring.

These groups may have a substituent. Preferable examples of the alkyl group having a substituent include an aminoalkyl group (preferably having 1 to 20 carbon atoms), a hydroxyalkyl group (preferably having 1 to 20 carbon atoms), and a cyanoalkyl group ( It preferably has 1 to 20 carbon atoms).

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 group in the formulae (A) to (E) is preferably an unsubstituted alkyl group.

Preferred compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, and piperazine. , aminomorpholine, aminoalkylmorpholine, piperidine and the like. More preferred compounds include compounds having an imidazole structure, a diazobicyclic structure, a cesium hydroxide structure, a ruthenium carboxylate structure, a trialkylamine structure, an aniline structure, or a pyridine structure, and an alkyl group having a hydroxyl group and/or an ether bond. An amine derivative, an aniline derivative having a hydroxyl group and/or an ether bond, and the like.

Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, benzimidazole and the like. Examples of the compound having a diazobicyclic structure include 1,4-diazabicyclo[2,2,2]octane, 1,5-diazabicyclo[4,3,0]non-5-ene, 1,8 -Diazabicyclo[5,4,0]undec-7-ene. Examples of the compound having a ruthenium hydroxide salt structure include triarylsulfonium hydroxide, benzoquinone hydroxide, ruthenium hydroxide having a 2-oxoalkyl group (more preferably triphenylsulfonium hydroxide, and hydroxide hydroxide (third Butylphenyl) hydrazine, hydrazine hydroxide (t-butylphenyl) hydrazine, phenylhydrazinium thiophene salt, or 2-oxopropylthiophene hydroxide). Examples of the compound having a ruthenium carboxylate structure include an anion moiety in which a compound having a ruthenium hydroxide salt structure is converted into a carboxylic acid group (e.g., an acetate group, an adamantane-1-carboxylic acid group, and a perfluoroalkyl carboxylic acid) a compound of the formula). Examples of the compound having a trialkylamine structure include tri(n-butyl)amine, tri(n-octyl)amine, and the like. Examples of the compound having an aniline structure include 2,6-diisopropylaniline, N,N-dimethylaniline, N,N-dibutylaniline, N,N-dihexylaniline and the like. Examples of the alkylamine derivative having a hydroxyl group and/or an ether bond include ethanolamine, diethanolamine, triethanolamine, methoxy(methoxyethoxyethyl)amine and the like. Examples of the aniline derivative having a hydroxyl group and/or an ether bond include N,N-fluorene (hydroxyethyl)aniline and the like.

It may use one of these basic compounds or a combination of two or more thereof.

The basic compound is used in an amount of usually 0.001 to 10% by mass, preferably 0.01 to 5% by mass, based on the solid matter in the resist composition.

Preferably, the acid generator and the basic compound are used in the composition at a molar ratio of an acid generator/basic compound of 2.5 to 300. That is, from the viewpoint of sensitivity and resolution, it is preferably a molar ratio of 2.5 or more, and is preferable from the viewpoint of preventing the resolution from being lowered due to the thickening of the photoresist pattern over time during the exposure to heating. It is a ratio of 300 or less. The acid generator/basic compound molar ratio is more preferably from 5.0 to 200, and still more preferably from 7.0 to 150.

(F) surfactant

The photoresist composition according to the present invention preferably contains a surfactant (F). More preferably, it contains one or more interfaces selected from the group consisting of fluorine-based and/or ruthenium-based surfactants (fluorine-based surfactants, ruthenium-based surfactants, and surfactants having fluorine and ruthenium atoms). Active agent.

Since the (F) surfactant is contained in the photoresist composition according to the present invention, it can exhibit favorable sensitivity and resolution during use of an exposure source of 250 nm or less, particularly 220 nm or less. Degree and high adhesion, and the photoresist pattern with few development failures.

Examples of the fluorine and/or rhodium-based surfactant include those described in JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950, and JP-A. -63-34540, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, JP-A-2000-277862 Patent, US Patent No. U.S. Patent No. 5, 405, 720, U.S. Patent No. 5,360, 692, U.S. Patent No. 5, 527, 988, U.S. Patent No. 5,296,330, U.S. Patent No. 5, 436, 098, U.S. Patent No. 5,576, 143 Surfactant, U.S. Patent No. 5,294,511, and U.S. Patent No. 5,824,451. The commercially available surfactants shown below can also be used directly.

Examples of commercially available surfactants which may be used herein include fluorine and/or hydrazine as main surfactants, such as Eftops E301 and EF 303 (manufactured by Shin-Akita Kasei KK), Florad FC430, 431 and 4430 (Sumitomo 3M, Inc., manufactured by Megafac F171, F173, F176, F189, F113, F110, F117, F120, and R08 (manufactured by Dainippon Ink & Chemicals, Inc.), Surflon S-382, SC101, 102, 103, 104, 105, and 106 (manufactured by Asahi Glass Co., Ltd.), Troysol S-366 (manufactured by Troy Chemical Industries, Inc.), GF-130 and GF-150 (manufactured by TOA GOSEI Co., Ltd.), Surflon S- 393 (manufactured by AGC SEIMI CHEMICAL Co., Ltd.), Eftops EF121, EF122A, EF122B, RF122C, EF125M, EF135M, EF351, 352, EF801, EF802, and EF601 (manufactured by JEMCO Inc.), PF636, PF656, PF6320, and PF6520 (manufactured by OMNOVA), FTXs-204G, 208G, 218G, 230G, 204D, 208D, 212D, 218D, and 222D (manufactured by NEOS Co.). A polyoxyalkylene polymer KP-341 (manufactured by Shin-Etsu Chemical Industry Co., Ltd.) can also be used as the main polymer of ruthenium.

In addition to the above-mentioned well-known surfactants, polymers including fluoroaliphatic groups derived from short-chain polymerization (also known as short-chain polymer methods) or oligomerization processes (also known as oligomers) may also be used. The surfactant of the fluoroaliphatic compound produced by the method). This fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.

As the polymer having a fluoroaliphatic group, it preferably has a fluoroaliphatic group. a copolymer of a monomer with (poly(oxyalkylene)) acrylate and/or (poly(oxyalkylene)) methacrylate. It allows for the random distribution of copolymers or block copolymers. Examples of the poly(oxyalkylene) group include poly(oxyethyl), poly(oxypropyl), poly(oxybutylene), and the like. It is also possible to use units having an alkyl group having a different chain length in a single chain, such as poly(oxyethyl-oxy-extension-oxy-extension ethyl block unit) and poly(oxygen-extension ethyl-oxygen-extended) Base block unit). Further, a copolymer or dimer of a monomer other than a fluoroaliphatic group and (poly(oxyalkylene)) acrylate (or methacrylate) may be used, and at the same time, two or more copolymerizations may be used. A terpolymer or higher copolymer having a different fluoroaliphatic group and two or more different (poly(oxyalkylene)) acrylate (or methacrylate).

Examples of commercially available surfactants include Megafacs F178, F-470, F-473, F-475, F-476, and F-472 (manufactured by Dainippon Ink & Chemicals, Inc.). Other examples include copolymers containing C ₆ F ₁₃ acrylate (or methacrylate) and (poly(oxyalkylene)) acrylate (or methacrylate), C ₃ F ₇ -based acrylate (or Copolymer of methacrylate) with (poly(oxyethylidene)) acrylate (or methacrylate) and (poly(oxypropyl)) acrylate (or methacrylate).

The present invention may also use a surfactant other than fluorine and/or cerium as the main surfactant. As for the specified examples, nonionic surfactants such as polyoxyethylene ethyl ether, such as polyoxyethylidene ethyl ester, polyoxyethylene ethyl stearyl ether and polyoxyethylene ethyl ether, may be listed. Polyether alkyl ethyl aryl ether, such as polyoxyethylene ethyl octyl phenol ether and polyoxyethyl decyl phenol ether; polyoxyl extension Ethyl/polyoxypropyl propyl block copolymer; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan Oleic acid ester, sorbitan trioleate, and sorbitan tristearate; polyoxyethylene ethyl sorbitan fatty acid ester, such as polyoxyethylene ethyl sorbitan monolaurate, polyoxyl Ethyl sorbitan monopalmitate, polyoxyethylene ethyl sorbitan monostearate, polyoxyethyl sorbitan trioleate, and polyoxyethylene sorbitan tristearyl Acid esters, etc.

It may use one of these surfactants or a combination of two or more thereof.

The surfactant (F) is preferably used in an amount of from 0.01 to 10% by mass, more preferably from 0.1 to 5% by mass, based on the total of the photoresist composition (excluding the solvent).

(G) cerium carboxylate

The photoresist composition according to the present invention may comprise (G) a phosphonium carboxylate salt. Examples of the cerium carboxylate salt include a cerium carboxylate salt, a carboxylic acid iodide salt, a carboxylate ammonium salt, and the like. In particular, the (G) cerium carboxylate salt is preferably an iodide salt and a phosphonium salt thereof. Further, the carboxylic acid residue used in the (G) acid cerium salt of the present invention preferably contains no aromatic group and carbon-carbon double bond. The anion moiety is preferably a linear, branched, monocyclic, or polycyclic alkylcarboxylate anion having from 1 to 30 carbon atoms, more preferably an anion of a carboxylic acid in which the alkyl group is partially or fully fluorinated. The alkyl chain may contain an oxygen atom. Due to this configuration, it ensures transparency to light of 220 nm or less, enhances sensitivity and resolution, and improves the defocusing latitude and exposure range of the attached pitch.

Examples of the anion of the fluorine-substituted carboxylic acid include fluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, pentafluoropropionic acid, heptafluorobutyric acid, nonafluoropentanoic acid, and perfluorododecane An anion such as carbonic acid, perfluorotridecanoic acid, perfluorocyclohexanecarboxylic acid or 2,2-fluorene trifluoromethylpropionic acid.

These (G) cerium carboxylate salts can be synthesized by reacting cerium hydroxide, cerium hydroxide or ammonium hydroxide, and a carboxylic acid with silver oxide in a suitable solvent.

The content of the (G) cerium carboxylate salt in the composition is usually from 0.1 to 20% by mass, preferably from 0.5 to 10% by mass, more preferably from 1 to 7% by mass, based on the total solids of the composition.

(H) Other additives

If necessary, the photoresist composition according to the present invention may further contain a dye, a plasticizer, a photosensitizer, a light absorber, an alkali-soluble resin, a dissolution inhibitor, and a compound which accelerates dissolution in a developer (for example, a molecular weight of 1,000 or more) Small phenolic compounds, or alicyclic or aliphatic compounds having a carboxyl group, and the like.

The phenolic compound having a molecular weight of 1,000 or less can be referred to by those skilled in the art, for example, as described in JP-A-4-122938, JP-A-2-28531, U.S. Patent No. 4,916,210, and European Patent No. 219,294. The method is easy to synthesize.

Specific examples of the alicyclic or aliphatic compound having a carboxyl group include a carboxylic acid derivative having a steroid structure (e.g., cholic acid, deoxycholic acid and lithocholic acid), an adamantanecarboxylic acid derivative, an adamantane dicarboxylic acid, and a ring. Hexanecarboxylic acid, cyclohexanecarboxylic acid, cyclohexanedicarboxylic acid and the like, although the invention is not limited thereto.

In the pattern forming method according to the present invention, a film made of a resin composition which exhibits an increase in solubility in a positive developing solution and a decrease in solubility in a negative developing solution upon irradiation with actinic rays or radiation is formed on the substrate. step The step of exposing the film, the step of heating the film, and the step of subjecting the film to positive development can be carried out by a known method.

Although the wavelength of the light source used for the exposure apparatus in the present invention is not particularly limited, it is possible to use KrF excimer laser beam wavelength (248 nm), ArF excimer laser beam wavelength (193 nm), F _{2 .} Excimer laser beam wavelength (157 nm) and so on.

The dipping method can be used in the exposure step of the present invention.

The dipping method is a technique in which a liquid having a high refractive index (hereinafter also referred to as "impregnation liquid") is filled between a projection lens and a sample.

Regarding the "impregnation effect", the resolution and the depth of focus can be expressed by the following formula, where λ ₀ represents the exposure wavelength in air, n represents the refractive index of the air immersed in the liquid, θ represents the convergence half angle of the light, and NA ₀ refers to sin θ.

(resolution) = k ₁ . (λ ₀ /n)/NA ₀

(focus depth) = ± k ₂ . (λ ₀ /n)/NA ₀ ²

That is, the impregnation effect is equal to the exposure using a wavelength of 1/n. In other words, in the case of an optical projection system using the same NA, the impregnation can increase the depth of focus by a factor of n. It is effective for any pattern, and can be combined with super-analytical techniques currently being studied, such as phase shifting and anamorphic lighting.

In the impregnation method, the membrane surface is washed with an aqueous solution between (1) a step of forming a film on the substrate and an exposure step and/or (2) between a step of exposing the film by the immersion liquid and a step of heating the film. step.

As for the immersion liquid, it is preferred to use a liquid which is transparent to the exposure wavelength and has as small a temperature coefficient of refraction as possible to minimize distortion of the optical image projected on the photoresist. Especially when using ArF excimer laser light In the case of a beam (wavelength: 193 nm) as an exposure light source, in addition to the above discussion, water is advantageously used because of its high availability and ease of handling.

In the case of using water as the immersion liquid, it is possible to use a small amount of an additive (liquid) which does not cause dissolution of the photoresist layer on the wafer and which has only a negligible effect on the optical coating on the lower surface of the lens device, thereby reducing the surface tension of the water and Improve interface activity.

As the additive, it is preferred to use an aliphatic alcohol having a refractive index almost the same as that of water, such as methanol, ethanol, isopropanol or the like. By adding an alcohol having a refractive index almost the same as that of water, there is an advantage that even if the alcohol component in the water evaporates and changes its concentration, the refractive index change of all the liquids can be minimized.

On the other hand, when the immersion liquid is contaminated by a material having opacity of 193 nm or a refractive index different from water, the optical image projected on the photoresist is deformed. Therefore, it is preferred to use distilled water as water. Pure water filtered through, for example, an ion exchange filter can also be used.

In the present invention, the substrate on which the film is formed is not particularly limited. For example, it may be a method commonly used for manufacturing a semiconductor such as an IC, a method of manufacturing a circuit substrate such as a liquid crystal or a heating head, and other optical applications such as an inorganic substrate made of ruthenium, SiN, SiO ₂ or the like, or SOG. A substrate of a lithography method coated with an inorganic substrate. If necessary, an organic anti-reflection film can be formed between the film and the substrate.

It is preferred to perform positive development using an alkaline developer.

As the alkaline developing solution for positive development, an inorganic base (for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium citrate, sodium metasilicate) can be used. , with ammonia); primary amines (such as ethylamine and n-propylamine); secondary amines (such as diethylamine and di-n-butylamine); tertiary amines (such as triethylamine and methyldiethylamine); Such as dimethylethanolamine and triethanolamine); quaternary ammonium salts (such as tetramethylammonium hydroxide and tetraethylammonium hydroxide); and an aqueous alkaline solution of a cyclic amine (such as pyrrole and piperidine).

It is also possible to use an alkaline developer which is further contained in an amount of an alcohol or a surfactant.

The alkali concentration in the alkaline developer is usually from 0.1 to 20% by mass.

The pH of the alkaline developer is usually from 10.0 to 15.0.

It is particularly desirable to be a 2.38% aqueous solution of tetramethylammonium hydroxide.

In the washing treatment performed after the positive development, pure water was used as the washing liquid. It is also possible to add a suitable surfactant to it.

In the case of negative development, it is preferred to use an organic developer containing an organic solvent.

As the organic developing solution which can be used for negative development, a polar solvent such as a ketone solvent, an ester solvent, an alcohol solvent, a guanamine solvent or an ether solvent, and a hydrocarbon solvent can be used.

Examples of usable ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexyl Ketone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetyl ketone acetone, acetone acetone, ionone, diacetone alcohol, acetonitrile methanol, acetophenone, methyl naphthalene Ketone, isophorone, propyl carbonate, and the like.

Examples of useful ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, and ethylene. Alcohol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl 3-ethoxypropionate, 3-methoxybutyl acetate, acetic acid 3- Methyl-3-methoxybutyl ester, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, and the like.

Examples of the alcohol solvent include alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, second butanol, third butanol, isobutanol, n-hexanol, n-heptanol, n-octanol, and Sterols, etc.; glycol solvents such as ethylene glycol, diethylene glycol, triethylene glycol, etc.; and glycol ether solvents such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol, propylene glycol, two Ethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methoxy methyl butanol and the like.

Examples of the ether solvent include the above glycol ether solvent, dioxane, tetrahydrofuran, and the like.

Examples of the available guanamine solvent include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphoric acid triamide, 1, 3-dimethyl-2-imidazolidinone and the like.

Examples of the hydrocarbon solvent include aromatic hydrocarbon solvents such as toluene, xylene, and the like, and aliphatic hydrocarbon solvents such as pentane, hexane, octane, decane, and the like.

It can use two or more of these solvents. Further, the above solvent may be mixed with other solvents or water.

As an example of the developing system, there may be listed a method including a method of accumulating a developing solution on a surface of a substrate due to surface tension, and allowing it to stand for a defined time to perform development (paddle method), and a method of spraying a developing solution on a surface of a substrate The method of spraying (spraying method), comprising rotating the substrate at a defined speed and continuously coating the developer solution by scanning the developer liquid nozzle at a defined speed Overlay method (dynamic allocation method), etc. In the case where the negative developing solution has a high vapor pressure in the developing method, it evaporates and cools the surface of the substrate by the developing solution, thereby lowering the temperature of the developing solution. Thus, the dissolution rate of the photoresist composition film formed on the substrate cannot be fixed, which deteriorates the dimensional stability. Therefore, the developer which can be used for negative development is preferably a vapor pressure of 5 kPa or less, more preferably 3 kPa or less, and most preferably 2 kPa or less at 20 °C.

Specific examples of the developing solution having a vapor pressure of 5 kPa or less include ketone solvents such as 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, 4-heptanone, 2-hexanone, and Isobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl isobutyl ketone, etc.; ester solvent, such as butyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol Ethyl acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl 3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl acetate -3-methoxybutyl ester, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, etc.; alcohol solvent, such as n-propanol, isopropanol, n-butanol, second butanol , tert-butanol, isobutanol, n-hexanol, n-heptanol, n-octanol, n-decyl alcohol, etc.; glycol solvent, such as ethylene glycol, diethylene glycol, triethylene glycol, etc.; glycol ether solvent Such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol, propylene glycol, diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methoxy methyl butanol, etc.; ether solvent, such as tetrahydrofuran, etc. ; guanamine solvent, N-methyl-2-pyrrolidone, N,N-dimethylacetamide and N,N-dimethylformamide; aromatic hydrocarbon solvents such as toluene, xylene, etc.; and aliphatic hydrocarbon solvents Such as octane, decane and the like.

a developer having a vapor pressure of 2 kPa or less (ie, a better range) Examples include ketone solvents such as 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, 4-heptanone, 2-hexanone, diisobutylketone, cyclohexanone, methylcyclohexane Ketone, phenylacetone, etc.; ester solvent, such as butyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol Alcohol monoethyl ether acetate, ethyl 3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, ethyl lactate, butyl lactate, lactate Ester, etc.; alcohol solvent, such as alcohol, such as n-butanol, second butanol, tert-butanol, isobutanol, n-hexanol, n-heptanol, n-octanol, n-nonanol, etc.; glycol solvent, such as B Glycol, diethylene glycol, triethylene glycol, etc.; glycol ether solvent, such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol, propylene glycol, diethylene glycol monomethyl ether, triethylene glycol Monoethyl ether, methoxymethylbutanol, etc.; guanamine solvent, such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide and N,N-dimethylformamide; An aromatic hydrocarbon solvent such as xylene; and an aliphatic hydrocarbon solvent Such as octane, decane and the like.

If necessary, the developer which can be used for negative development can contain an appropriate amount of surfactant.

The surfactant is not particularly limited, and for example, ionic or nonionic fluorine and/or ruthenium may be used as the main surfactant. The fluorine and/or bismuth-based surfactants in this example are described in JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950, JP-A. -63-34540, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, U.S. Patent No. 5,405,720, U.S. Patent No. 5,360,692, U.S. Patent No. 55,291,881, U.S. Patent No. 5,296,330, U.S. Patent No. 5,436,098, U.S. Patent No. 5,576,143 Surfactant, U.S. Patent No. 5,294,511, and U.S. Patent No. 5,824,451. A nonionic surfactant is preferred. Although the nonionic surfactant is not particularly limited, it is particularly preferable to use a fluorine-based or ruthenium-based surfactant directly.

The surfactant is usually used in an amount of from 0.001 to 5% by mass, preferably from 0.005 to 2% by mass, and more preferably from 0.01 to 0.5% by mass, based on the total developer.

As an example of the developing method, there may be listed a method including immersing the substrate in a bath for filling the developing solution for a defined time (soaking method), one including accumulating the developer on the surface of the substrate due to surface tension, and allowing it to be static a method of defining a time and thus developing (paddle method), a method comprising spraying a developer onto a surface of a substrate (spraying method), a method comprising rotating the substrate at a defined speed and scanning the developing solution nozzle at a defined speed It is a method of continuously coating a developing solution (dynamic dispensing method) or the like.

After the step of performing negative development, it may be subjected to a step of stopping development by replacing with another solvent.

After the negative development, it is preferably a step of washing with a negative development developing solution containing an organic solvent.

After cleaning with the negative development cleaning liquid, it is preferred to rotate the substrate at a rotation speed of 2000 rpm to 4000 rpm, thereby removing the washing liquid from the surface of the substrate. In the case where the washing liquid has a low vapor pressure, even after the washing liquid is removed by rotating the substrate, the washing liquid remains on the substrate. The residual washing liquid penetrates into the photoresist pattern that has been formed on the substrate, and thus the photoresist pattern expands. As a result, the dimensional stability of the photoresist pattern deteriorates. Therefore, it is preferred that the washing liquid is 20 ° C has a vapor pressure of 0.05 kPa or higher, more preferably 0.1 kPa or higher, and most preferably 0.12 kPa or higher.

In the washing step after the negative development, it is preferably washed with a washing liquid containing at least one selected from the group consisting of a hydrocarbon solvent, a ketone solvent, an ester solvent, an alcohol solvent, a guanamine solvent, and an organic solvent with an ether solvent. More preferably, the cleaning step is carried out after the negative development using a washing liquid containing at least one organic solvent selected from the group consisting of a ketone solvent, an ester solvent, an alcohol solvent, and a guanamine solvent. It is still more preferable to carry out the washing step using a washing liquid containing an alcohol solvent or an ester solvent after the negative development. It is particularly preferred to carry out the washing step using a washing liquid containing a monohydric alcohol having 5 to 8 carbon atoms after negative development. Examples of monohydric alcohols having 5 to 8 carbon atoms which can be used in the post-development post-development washing step include linear, branched and cyclic monohydric alcohols such as 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., and preferably 1- Hexanol, 2-hexanol and 2-heptanol.

The above individual components may be a mixture of a plurality of components. Mixtures of organic solvents other than those listed above can also be used.

The water content of the washing liquid is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less. By adjusting the water content to 10% by mass or less, it is possible to establish advantageous developing properties.

A washing liquid containing an appropriate amount of a surfactant may also be used.

In the washing step, it cleans the wafer which has undergone negative development using the above-described organic solvent-containing cleaning liquid. The cleaning treatment method is not particularly limited. For example, it may be a method including a substrate coated with a washing liquid at a defined speed rotation (spin coating method), and a method comprising immersing the substrate in a filling washing liquid. A method of defining a time in a tank (soaking method), a method including spraying a washing liquid on a surface of a substrate (spraying method), and the like. Preferably, the cleaning treatment is performed by a spin coating method, and after the cleaning is completed, the substrate is rotated at a rotation speed of 2000 rpm to 4000 rpm, thereby removing the washing liquid from the substrate.

[Example]

The invention will now be described with reference to the following examples, although the invention is not limited thereto.

[Synthesis Example 1: Synthesis of Resin (A1)]

In a three-necked flask, 20 g of a mixture including propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether in a ratio (mass ratio) of 6/4 was introduced under a nitrogen stream, and heated to 80 ° C (solvent 1). Γ-butyrolactone methacrylate, hydroxyadamantane methacrylic acid and 2-methyl-2-adamantyl methacrylate were added in a molar ratio of 45/15/40 (mass ratio) of 6/ A solvent mixture of 4 propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether to produce 22% by mass of a monomer solution (200 g). To this solution, 8 mol% of a polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) was added and dissolved. The resulting solution was dropped into the above solvent 1 for 6 hours. After the end of the dropwise addition, the reaction mixture was reacted at 80 ° C for another 2 hours. The liquid reaction mixture was then cooled by standing and poured into hexane 1800 ml / ethyl acetate 200 ml. The thus precipitated powder was collected by filtration and dried. 37 g of the resin (A1) was thus obtained. The obtained resin (A1) had a weight average molecular weight of 9,500 and a degree of dispersion (Mw/Mn) of 1.80.

(Resin A1) Mw = 9500, Mw / Mn = 1.80

Moer composition ratio 45/15/40

[Photoresist composition (A1)]

The following ingredients were dissolved in a solvent mixture of polyethylene glycol monomethyl ether acetate/polyethylene glycol monomethyl ether (60:40), and the resulting solution having a solid concentration of 5.8% by mass was passed through a 0.1 micron polyethylene filter. filter. The positive resist composition (A1) was thus prepared.

Resin (A1) 1.83 g, triphenylsu lfonium nonaf late 69.6 mg, diphenylaniline 8.7 mg, and PF6320 (fluorine-based surfactant manufactured by OMNOVA) 1.7 mg.

[Photoresist composition (A2)]

The photoresist composition (A2) was prepared using the following resin (A2) as a substitute for the resin (A1).

(Resin A2) Mw = 8000, Mw / Mn = 1.85

Moer composition ratio 50/10/40

[Photoresist composition (A3)]

The photoresist composition (A3) was prepared using the following resin (A3) as a substitute for the resin (A1).

(Resin A3) Mw = 7500, Mw / Mn = 1.80

Moer composition ratio 50/5/45

[Photoresist composition (A4)]

The photoresist composition (A4) was prepared using the following resin (A4) as a substitute for the resin (A1).

(Resin A4) Mw = 7500, Mw / Mn = 1.80

Moer composition ratio 50/5/45

[Photoresist composition (A5) to (A9)]

The photoresist compositions (A5) to (A9) were prepared using the following resins (A5) to (A9) as a substitute for the resin (A1).

(Resin A5) Mw = 10500, Mw / Mn = 1.95

Molar composition ratio 45/5/50

(Resin A6) Mw=12500, Mw/Mn=1.65

Molar composition ratio 42/8/50

(Resin A7) Mw = 8200, Mw / Mn = 1.60

Moer composition ratio 38/13/49

(Resin A8) Mw=11200, Mw/Mn=1.80

Molar composition ratio 50/2/48

(Resin A9) Mw = 10000, Mw / Mn = 1.85

Moer composition ratio 50/4/46

[Photoresist composition (B)]

The photoresist composition (B) was prepared using the following resin (B) as a substitute for the resin (A1).

(Resin B) Mw = 9200, Mw / Mn = 1.95

Moer composition ratio 40/20/40

[Photoresist composition (C) and (D)]

The photoresist compositions (C) and (D) were prepared using the following resins (C) and (D) as a substitute for the resin (A1).

(Resin C) Mw = 6200, Mw / Mn = 1.95

Molar composition ratio 15/85

(Resin D) Mw=1200, Mw/Mn=2.00

Molar composition ratio 10/90

[Example 1]

An organic anti-reflection film ARC29A (manufactured by Nissan Chemical Industries, Ltd.) was coated on a tantalum wafer, and baked at 205 ° C for 60 seconds to form a 78 nm antireflection film. Then, the photoresist composition (A1) was applied thereon, and baked at 120 ° C for 60 seconds to form a 150 nm photoresist film. The resulting wafer was exposed in a pattern using an ArF excimer laser scanner (NA 0.75). After heating at 120 ° C for 60 seconds, the wafer was subjected to (negative) development for 60 seconds by a spray method using butyl acetate (negative type developer) to rotate the wafer at a rotation speed of 1000 rpm. Thus, a 150 nm (1:1) line and gap photoresist pattern was obtained.

[Example 2]

An organic anti-reflection film ARC29A (manufactured by Nissan Chemical Industries, Ltd.) was coated on a tantalum wafer, and baked at 205 ° C for 60 seconds to form a 78 nm antireflection film. Then, the photoresist composition (A1) was applied thereon, and baked at 120 ° C for 60 seconds to form a 150 nm photoresist film. The resulting wafer was exposed in a pattern using an ArF excimer laser scanner (NA 0.75). After heating at 120 ° C for 60 seconds, the wafer was subjected to (negative) development for 60 seconds by a spray method using butyl acetate (negative type developer) to rotate the wafer at a rotation speed of 1000 rpm. The wafer was then continuously rotated to wash the wafer with 1-hexanol for 30 seconds. The wafer was then rotated at 4000 rpm for 30 seconds to remove the wash solution. So get A 150 nm (1:1) line and gap photoresist pattern.

[Examples 3 to 5 and 8 to 13 and Comparative Examples 1 and 2]

As in Example 2, a 150 nm (1:1) line and gap photoresist pattern was obtained, but each of the photoresist compositions (A2) to (A9), (B), (C), and (D) was used.

[Example 6]

An organic anti-reflection film ARC29A (manufactured by Nissan Chemical Industries, Ltd.) was coated on a tantalum wafer, and baked at 205 ° C for 60 seconds to form a 78 nm antireflection film. Then, the photoresist composition (A1) was applied thereon, and baked at 120 ° C for 60 seconds to form a 150 nm photoresist film. The resulting wafer was exposed in a pattern using an ArF excimer laser scanner (NA 0.75). After heating at 120 ° C for 60 seconds, the wafer was subjected to (positive type) development for 30 seconds using an aqueous solution of tetramethylammonium hydroxide (2.38 mass%) (positive type developing solution), and then washed with pure water. This gives a pattern of 600 nm pitch and 450 nm line width. Next, the wafer was subjected to (negative) development for 60 seconds by a spray method using butyl acetate (negative type developer) to rotate the wafer at a rotation speed of 1000 rpm. The wafer was then continuously rotated to wash the wafer with 1-hexanol for 30 seconds. The wafer was then rotated at 4000 rpm for 30 seconds to remove the wash solution. This gave a 150 nm (1:1) line and gap photoresist pattern.

[Example 7]

An organic anti-reflection film ARC29A (manufactured by Nissan Chemical Industries, Ltd.) was coated on a tantalum wafer, and baked at 205 ° C for 60 seconds to form a 78 nm antireflection film. Then, the photoresist composition (A) was applied thereon, and baked at 120 ° C for 60 seconds to form a 150 nm photoresist film. The resulting wafer was exposed in a pattern using an ArF excimer laser scanner (NA 0.75). At 120 After heating at ° C for 60 seconds, the wafer was subjected to (negative) development for 60 seconds by a spray method using butyl acetate (negative type developing solution) while rotating the wafer at a rotation speed of 1000 rpm. The wafer was then continuously rotated to wash the wafer with 1-hexanol for 30 seconds. The wafer was then rotated at 4000 rpm for 30 seconds to remove the wash solution. This gives a pattern of 600 nm pitch and 450 nm line width. Next, the wafer was subjected to (positive type) development for 30 seconds using an aqueous solution of tetramethylammonium hydroxide (2.38 mass%) (positive type developing solution), and then washed with pure water. This gave a 150 nm (1:1) line and gap photoresist pattern.

<Evaluation of Line Edge Thickness (LER)>

The 150 nm (1:1) line and gap resist patterns obtained in Examples 1 to 13 and Comparative Examples 1 and 2 were observed under a scanning electron microscope (S-9260 manufactured by Hitachi, Ltd.). In the 2 micron region in the longitudinal direction of the 150 nanowire pattern, the standard line which is assumed to be the edge is measured at 50 points. The standard deviation was determined in this way and 3σ was calculated. The smaller the value, the better the performance. Table 1 summarizes the results.

[Examples 14 to 27 and Comparative Examples 3 and 4]

As in Example 7, a 150 nm (1:1) line and gap resist pattern was obtained, but a combination of each negative type developing solution listed in Table 3 and a negative type developing washing liquid was used.

[Example 28]

As in Example 7, a 150 nm (1:1) line and gap photoresist pattern was obtained, but a photoresist composition (B) was used.

Table 2 shows the vapor pressure and boiling point of each solvent used for the negative developing solution and the negative developing developing washing liquid.

<Evaluation of dimensional uniformity>

Observed under a scanning microscope (S-9260, manufactured by Hitachi, Ltd.) Each 150 nm (1:1) line and gap photoresist pattern obtained in Examples 14 to 28 and Comparative Examples 3 and 4. 50 points were measured at 2 nm intervals and the standard deviation of 50 points was determined and 3σ was calculated. The smaller the value, the better the performance. Table 3 summarizes the results. In Table 3, the mass ratio indicates a case where a combination of two organic solvents is used as a negative developing solution, or a combination of two organic solvents is used as a negative developing cleaning liquid, and two solvents are used together. Mix the mass ratio. In the case where the negative developing solution or the negative developing washing liquid includes a single organic solvent, the mass ratio is 100.

As shown in Table 3, by combining the photoresist composition according to the present invention with the negative developer and the negative developer cleaning liquid according to the present invention, it is possible to stably obtain a reduced line edge roughness and excellent. Highly precise fine pattern of dimensional uniformity.

According to the present invention, there is provided a pattern forming method capable of alleviating the thickness of a line edge and improving dimensional stability, a photoresist composition for negative development for use in the method, and a light for multiple development of the method. A resist composition, a negative developer for use in the method, and a negative developer for use in the method.

The entire disclosure of each of the foreign patent applications in the present application, which is hereby incorporated by reference in its entirety, is hereby incorporated by reference.

[Fig. 1]

A‧‧‧Exposure dose

B‧‧‧Digital development

C‧‧‧Exposure dose

D‧‧‧Negative development

[Fig. 2]

A‧‧‧Exposure dose

B‧‧‧ Wafer pattern

C‧‧‧Parts to be removed with organic solvents

D‧‧‧Parts to be removed with an alkaline aqueous solution

E‧‧‧Parts to be removed with organic solvents

F‧‧‧Parts to be removed with an alkaline aqueous solution

G‧‧‧Parts to be removed with organic solvents

[Fig. 3]

A‧‧‧Full image (light intensity distribution)

B‧‧‧ Wafer pattern

C‧‧‧Parts to be removed with negative developer

D‧‧‧Parts to be removed with positive developer

E‧‧‧Parts to be removed with negative developer

F‧‧‧Parts to be removed with positive developer

G‧‧‧Parts to be removed with negative developer

[Fig. 4]

A‧‧‧ Residual film ratio (%)

B‧‧‧Exposure dose

C‧‧‧Exposure dose/residual film ratio curve in the case of positive developer

D‧‧‧ Residual film ratio (%)

E‧‧‧Exposure dose

F‧‧‧Exposure dose/residual film ratio curve in the case of negative developer

[Fig. 5]

A‧‧‧Exposure dose

B‧‧‧Digital development

C‧‧‧Exposure dose

D‧‧‧Negative development

[Picture 6]

A‧‧‧ positive development

B‧‧‧Negative development

[Picture 7]

A‧‧‧Full image (light intensity distribution)

B‧‧‧Exposure intensity of double exposure

C‧‧‧Exposure intensity for the first exposure

D‧‧‧Parts after the first (negative) exposure on the wafer

E‧‧‧Parts on the wafer after the first (positive) exposure

[Fig. 8]

A‧‧‧Light intensity

[Fig. 9]

A‧‧‧Light intensity

B‧‧‧Digital development

C‧‧‧critical value (a)

D‧‧‧min

[Fig. 10]

A‧‧‧Light intensity

[Fig. 11]

A‧‧‧Light intensity

B‧‧‧Negative development

C‧‧‧critical value (b)

D‧‧‧Line width

E‧‧‧max

Fig. 1 is a model diagram showing the relationship between positive development, negative development and exposure dose in the conventional method; Fig. 2 is a model diagram showing a pattern formation method using positive development and negative development in combination; A model diagram showing the relationship between positive development, negative development, and exposure dose; and Fig. 4 is a graph showing the relationship between exposure dose and residual film ratio using a positive developer or a negative developer; Model diagram of the relationship between positive development, negative development and exposure dose in the method according to the invention; Fig. 6 is a model diagram showing the relationship between positive development, negative development and exposure dose in the method according to the invention; Figure 7 is a model diagram showing the relationship between positive development, negative development and exposure dose in the method according to the present invention; Figure 8 shows the holographic intensity distribution of the optical image; and Figure 9 shows the positive development, the critical value. (a) a model map associated with light intensity; Fig. 10 shows a holographic intensity distribution of the optical image; and Fig. 11 is a model diagram showing the relationship between positive development, critical value (b) and light intensity.

Claims (17)

A pattern forming method comprising: (a) coating a photoresist composition comprising a resin comprising a repeating unit represented by the following formula (NGH-1) and increasing polarity and decreasing in negative due to an action of an acid a solubility in a developing solution which is a developing solution consisting essentially of an organic solvent; (b) exposure; and (d) development with the negative developing solution: Wherein R _NGH1 represents a hydrogen atom or an alkyl group; and R _NGH2 to R _NGH4 each independently represent a hydrogen atom or a hydroxyl group, provided that at least one of R _NGH2 to R _NGH4 represents a hydroxyl group. The pattern forming method according to claim 1, wherein the organic solvent contained in the negative developing solution is a ketone solvent, an ester solvent, an alcohol solvent or an ether solvent. The pattern forming method of claim 2, wherein the organic solvent is an ester solvent. The pattern forming method of claim 3, wherein the ester solvent is butyl acetate or amyl acetate. The pattern forming method of claim 1, wherein the negative developer has a vapor pressure of 5 kPa or less at 20 °C. The pattern forming method of claim 1, further comprising: (f) washing with a negative development developing solution including an organic solvent. The pattern forming method of claim 6, wherein the organic solvent contained in the washing liquid is a hydrocarbon solvent or an alcohol solvent. The pattern forming method of claim 7, wherein the organic solvent is an alcohol solvent. The pattern forming method of claim 8, wherein the alcohol solvent is a monohydric alcohol having 5 to 8 carbon atoms. The pattern forming method of claim 6, wherein the negative-type developing washing liquid has a vapor pressure of 0.1 kPa or more at 20 °C. The pattern forming method of claim 1, further comprising: (c) developing with a positive developer, the positive developer being an alkaline developer. The pattern forming method of claim 1, wherein the resin includes a repeating unit having a lactone group in addition to the repeating unit represented by the formula (NGH-1). The pattern forming method of claim 1, wherein the exposure system uses an ArF excimer laser. A pattern forming method comprising: (a) coating a photoresist composition comprising a resin comprising a repeating unit represented by the following formula (NGH-1) and increasing polarity and decreasing in negative due to an action of an acid a solubility in a developing solution which is a developing solution including a ketone solvent or an ester solvent; (b) exposure; and (d) development with the negative developing solution: Wherein R _NGH1 represents a hydrogen atom or an alkyl group; and R _NGH2 to R _NGH4 each independently represent a hydrogen atom or a hydroxyl group, provided that at least one of R _NGH2 to R _NGH4 represents a hydroxyl group. The pattern forming method of claim 14, wherein the developer comprises an ester solvent. The pattern forming method of claim 15, wherein the ester solvent is butyl acetate. The pattern forming method of claim 14, which further comprises: (c) developing with a positive developing solution which is an alkaline developing solution.