KR102417026B1 - Resist pattern formation method and resist - Google Patents

Abstract

The resist pattern formation method of the present invention is a radiation-sensitive resin composition containing an alkali-soluble resin (a), a crosslinking component (b), and a compound (c) that absorbs actinic radiation, wherein 100 parts by mass of the resin (a) In contrast, a preparation step of preparing a radiation-sensitive resin composition containing more than 1.0 parts by mass of the compound (c), a coating step of forming a coating film of the radiation-sensitive resin composition on a substrate, and a coating film at a first temperature It includes a first heat treatment step of heating, an exposure step of irradiating the obtained resist film with actinic radiation, and a second heat treatment step of maintaining the resist film under a second temperature condition after the exposure step is started. Here, the first temperature is equal to or greater than the second temperature.

Description

Resist pattern formation method and resist

The present invention relates to a resist pattern forming method and a resist, and more particularly, to a resist pattern forming method capable of forming a resist pattern having a reverse tapered cross section, and a resist having a resist pattern having a reverse tapered cross section.

In the photolithography technique, there are cases where a resist material capable of forming a resist pattern having an inversely tapered cross section is required. The case of forming a pattern by the lift-off method specifically, and the case of forming the electrically insulating barrier rib of an organic electroluminescent display element are mentioned. For example, when wiring is formed by the lift-off method using a resist pattern having a reverse tapered cross section, a metal wiring material is deposited on the outermost surface and bottom of the resist pattern having a reverse tapered cross section, and thereafter , the resist pattern is removed together with the metal wiring material deposited on the outermost surface. If the cross-section of the resist pattern has a reverse tapered shape, it is possible to suppress deposition of the metal wiring material on the sidewalls constituting the reverse tapered shape at the time of deposition of the metal wiring material, so that the metal wiring material deposited on the bottom of the resist pattern A wiring pattern consisting of

For this reason, conventionally, the photoresist composition which can form a high-sensitivity resist pattern with favorable reverse taper shape has been proposed (for example, refer patent document 1). The photoresist composition by patent document 1 contains alkali-soluble resin, two types of photo-acid generators, a crosslinking agent, and a solvent. More specifically, the two types of photo-acid generators contained in such a photoresist composition are halogen-containing photo-acid generators, one of which is easily distributed over a coating film obtained by applying the photoresist composition on a substrate, and the other is exposure and It is a triazine-based photoacid generator capable of improving the sensitivity of the photoresist composition in the development process. In particular, by dispersing a halogen-containing photo-acid generator on the upper part of the coating film to generate a relatively large amount of acid on the upper part of the coating film by exposure or heat treatment to form a relatively large number of cross-linked structures on the upper part of the coating film, a good reverse-tapered resist pattern was formed. .

Here, the process of depositing a metal wiring material on a resist pattern is generally performed in high temperature environment. Accordingly, the resist pattern is required to have excellent heat resistance. For this reason, conventionally, a radiation-sensitive resin composition having excellent heat resistance and capable of forming a resist pattern having a reverse tapered cross section has been proposed (for example, refer to Patent Document 2). The radiation-sensitive resin composition according to Patent Document 2 contains a specific alkali-soluble resin, a crosslinking component that crosslinks alkali-soluble resin, and a compound that absorbs actinic radiation. In particular, such a resin composition was realizing high heat resistance by using resin of a specific compounding as alkali-soluble resin.

Japanese Laid-Open Patent Publication No. 2013-527940 Japanese Laid-Open Patent Publication No. 2005-316412

In recent years, it is required to further refine|miniaturize the wiring pattern of a semiconductor device. In the miniaturization of the wiring pattern, it is necessary to make the angle formed by the sidewall constituting the reverse tapered shape of the resist pattern with respect to the resist surface more acute, that is, the taper angle (the angle formed by the sidewalls) must be made obtuse.

However, in the photoresist composition disclosed in Patent Document 1 and the radiation-sensitive resin composition disclosed in Patent Document 2, a resist pattern having a good reverse taper shape with a sufficiently large taper angle is formed, and also in a high temperature environment, such good reverse taper With regard to maintaining the shape, there is room for improvement.

Accordingly, an object of the present invention is to provide a resist pattern forming method capable of forming a resist pattern having a good reverse taper shape with a sufficiently large taper angle and maintaining a good reverse taper shape even in a high-temperature environment. Another object of the present invention is to provide a resist having a sufficiently large taper angle and a good reverse taper shape resist pattern, and capable of maintaining a good reverse taper shape even in a high-temperature environment.

MEANS TO SOLVE THE PROBLEM The present inventors earnestly examined for the purpose of solving the said subject. And, the present inventors mix|blended the compound which absorbs a predetermined amount or more of actinic radiation with respect to a radiation-sensitive resin composition, Moreover, when forming a resist pattern using this radiation-sensitive composition, the resist under predetermined temperature conditions. By forming the pattern, it was found that it was possible to form a resist pattern having a good reverse taper shape with a sufficiently large taper angle, and to maintain such a good reverse taper shape even in a high temperature environment, thereby completing the present invention.

That is, this invention aims to solve the said subject advantageously, and the resist pattern formation method of this invention is a preparation process of preparing a radiation-sensitive resin composition, and on a board|substrate, the said radiation-sensitive resin composition A coating step of applying and drying to form a coating film, a first heat treatment step of heating the coating film at a first temperature, an exposure step of irradiating actinic radiation to the resist film obtained through the first heat treatment step; a second heat treatment step of maintaining the resist film under a second temperature condition after initiation of the exposure step; A radiation-sensitive resin composition comprising a crosslinking component (b) that crosslinks the alkali-soluble resin by irradiation and subsequent heat treatment, and a compound (c) that absorbs the actinic radiation, comprising (1) the crosslinking component (b) ) is a combination of a compound that generates an acid upon irradiation with the actinic radiation, and a compound that crosslinks the alkali-soluble resin (a) using an acid generated by the actinic radiation as a catalyst, (2) the actinic radiation The absorbing compound (c) is contained in an amount exceeding 1.0 parts by mass with respect to 100 parts by mass of the alkali-soluble resin (a), and the first temperature is not less than the second temperature. Heating temperature in the 1st heat treatment process before an exposure process using the radiation-sensitive resin composition which contains the compound (c) which absorbs actinic radiation more than 1.0 mass part with respect to 100 mass parts of alkali-soluble resin (a) When the phosphorus first temperature is set to be equal to or higher than the second temperature in the second heat treatment step after the start of the exposure step to form a resist pattern, a good reverse taper shape can be obtained, and the good reverse taper shape can be maintained even under a high temperature environment. can

Here, in the present specification, the "reverse tapered shape" means that in addition to the standard tapered shape constituted by a surface inclined toward the taper apex, the open area on the resist surface is smaller than the open area at the bottom of the resist, It shall also include the structure of an overhang shape.

Moreover, in the resist pattern formation method of this invention, it is preferable that the said radiation-sensitive resin composition further contains the basic compound (d). This is because, when the radiation-sensitive resin composition contains the basic compound, the permissible range for the fluctuation of the second temperature can be expanded, and the flexibility of the resist pattern forming method can be improved.

Moreover, this invention aims at solving the said subject advantageously, and the resist of this invention is an alkali-soluble resin (a), irradiation of actinic radiation, or irradiation of actinic radiation and subsequent heat processing, A radiation-sensitive resin composition comprising a crosslinking component (b) that crosslinks an alkali-soluble resin, and a compound (c) that absorbs the actinic radiation, wherein (1) the crosslinking component (b) is irradiated with the actinic radiation a combination of a compound that generates an acid by reaction, and a compound that crosslinks the alkali-soluble resin (a) using the acid generated by the actinic radiation as a catalyst, (2) the compound (c) that absorbs the actinic radiation, With respect to 100 parts by mass of the alkali-soluble resin (a), when a resist pattern having a reverse tapered cross-section is formed using a radiation-sensitive resin composition containing more than 1.0 parts by mass, and consisting of lines and spaces, The ratio Wb/Wt of the line width Wt on the exposed surface to the line width Wb on the non-exposed surface is less than 0.7, and after heating for 1 minute under a temperature condition of 120° C., a reverse taper shape of the resist pattern is formed. It is characterized in that the angle the sidewall of the line makes with respect to the resist surface is less than 90°. Such a resist has a favorable taper shape and is excellent in heat resistance.

According to the present invention, it is possible to form a resist pattern having a good reverse taper shape and capable of maintaining such a good reverse taper shape even in a high-temperature environment.

ADVANTAGE OF THE INVENTION According to this invention, the resist which has a favorable reverse taper shape and the resist pattern excellent in heat resistance can be provided.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail. The resist pattern formation method of this invention can be used when forming the electrically insulating barrier rib of the manufacturing process of a semiconductor device or organic electroluminescent display element. In particular, the resist pattern forming method of the present invention relates to a reverse tapered resist pattern, and the resist of the present invention can be formed by the resist pattern forming method of the present invention.

(Resist pattern formation method)

The method for forming a resist pattern of the present invention includes a preparation step of preparing a radiation-sensitive resin composition, a coating step of coating and drying the resin composition on a substrate to form a coating film, and a first step of heating the coating film at a first temperature. a heat treatment step; an exposure step of irradiating actinic radiation to the resist film obtained through the first heat treatment step; and a second heat treatment step of maintaining the resist film under a second temperature condition after the exposure step is started. The radiation-sensitive resin composition prepared in the preparation step is an alkali-soluble resin (a), a cross-linking component (b) that cross-links alkali-soluble resin by irradiation with actinic radiation, or irradiation with actinic radiation and subsequent heat treatment, and active Contains a compound (c) that absorbs radiation. Further, the resin composition is characterized in that the crosslinking component (b) is a combination of a compound that generates an acid upon irradiation with actinic radiation, and a compound that crosslinks an alkali-soluble resin using an acid generated by actinic radiation as a catalyst. . Moreover, the resin composition contains more than 1.0 mass part of compound (c) which absorbs actinic radiation with respect to 100 mass parts of alkali-soluble resin (a).

In addition, the resist pattern forming method of the present invention may include a developing step of developing the resist film that has been subjected to the second heat treatment step.

The resist pattern forming method of the present invention is characterized in that the first temperature (so-called pre-bake temperature) is higher than or equal to the second temperature (so-called post-bake temperature). In this way, in forming a resist pattern using the resin composition, the heating temperature in the first heat treatment step before the exposure step is set to be equal to or higher than the second temperature in the second heat treatment step after the exposure step is started, so that the reverse taper A resist pattern having a good shape and capable of maintaining such a good reverse taper shape even in a high-temperature environment can be formed. Although the reason is not clear, it is guessed that it is as follows.

Conventionally, it was common to make the heating temperature in the 1st heat processing process before an exposure process lower than the heating temperature in the 2nd heat processing process after an exposure process. This was in order to sharpen the resist pattern obtained, without excessively increasing the exposure amount in an exposure process and reducing a resist sensitivity. Here, in the radiation-sensitive resin composition prepared in the preparation step, in particular, the compounding amount of the compound (c) that absorbs actinic radiation is more than 1.0 parts by mass with respect to 100 parts by mass of the alkali-soluble resin (a), more than before. characterized. When the compounding amount of the compound (c) that absorbs actinic radiation is large, it is assumed that the probability that the compound (c) is not uniformly dispersed and biased in the coating film formed using the resin composition in the application step increases. Accordingly, in the present invention, a resist film in which a high content of compound (c) is uniformly dispersed is formed by heat-treating a coating film formed using a resin composition containing a large amount of compound (c) at a pre-bake temperature equal to or higher than the post-bake temperature. It is conjectured that it can In addition, the dispersion state in the resist film of various components uniformly dispersed in the resist film by post-baking by making the pre-bake temperature equal to or higher than the post-bake temperature, in other words, by not raising the post-bake temperature higher than the pre-bake temperature. is maintained, and as a result, it is inferred that a good reverse taper shape can be formed.

Hereinafter, each process included in the resist pattern formation method of this invention is demonstrated.

<Preparation process>

In the preparation step, the radiation-sensitive resin composition comprising an alkali-soluble resin (a), a crosslinking component (b), and a compound (c) absorbing actinic radiation, and optionally further comprising a basic compound (d) and other components to prepare A radiation-sensitive resin composition is obtained by mixing components (a)-(d), for example. The obtained radiation-sensitive resin composition can be used for a coating process as it is. Alternatively, the radiation-sensitive resin composition solution can be prepared by adding and dissolving the components (a) to (d) in the solvent, and optionally performing a filtration treatment or the like. When mixing components (a) to (d) or dissolving (a) to (d) in a solvent, ball mill, sand mill, bead mill, pigment disperser, cerebral blaster, ultrasonic disperser, homogenizer, flask Known mixers, such as a netary mixer and a fill mix, can be used. In addition, at the time of filtration, the general filtration method using filter media, such as a filter, is employable. Hereinafter, each component which can be contained in the radiation-sensitive resin composition, and the solvent which can be used at the time of preparation of the radiation-sensitive resin composition solution are demonstrated.

[Radiation-sensitive resin composition]

The radiation-sensitive resin composition (hereinafter, simply referred to as "resin composition") used in the resist pattern forming method of the present invention is an alkali-soluble resin (a), irradiation with actinic radiation, or irradiation with actinic radiation and heat treatment thereafter. It contains the crosslinking component (b) which bridge|crosslinks alkali-soluble resin, and the compound (c) which absorbs actinic radiation. Further, the resin composition is characterized in that the crosslinking component (b) is a combination of a compound that generates an acid upon irradiation with actinic radiation, and a compound that crosslinks an alkali-soluble resin using an acid generated by actinic radiation as a catalyst. . Moreover, the resin composition is characterized by including more than 1.0 mass part of compound (c) which absorbs actinic radiation with respect to 100 mass parts of alkali-soluble resin (a). When the resin composition contains more than 1.0 part by mass of the compound (c) in particular, it is possible to form a resist pattern having a good reverse taper shape and to maintain such a good reverse taper shape even under a high temperature environment. Although the reason is not clear, it is guessed that it is as follows.

First, the compound (c) that absorbs actinic radiation is active in the exposure step of irradiating actinic radiation to the resist film obtained by coating the resin composition on a substrate in forming a resist having a resist pattern using the resin composition. It functions to absorb radiation. Accordingly, in the thickness direction of the resist film, a gradient is formed in the amount of the actinic radiation reaching from the side close to the exposure surface to the surface opposite to the exposure surface of the resist film. Specifically, the dose reaching the side close to the exposure surface increases, and the dose decreases as it approaches the surface on the opposite side to the exposure surface. Here, as a crosslinking component (b), the resin composition contains the compound which generate|occur|produces an acid by irradiation of actinic radiation, and the compound which crosslinks alkali-soluble resin using the acid which generate|occur|produced by actinic radiation as a catalyst. For this reason, if there is a gradient in the dose of actinic radiation reaching in the thickness direction of the resist film, more bridges are formed in the vicinity of the exposure surface with a high dose, and the bridges formed decrease as they move away from the exposure surface. For this reason, it becomes difficult to remove the resist film in the vicinity of an exposure surface in a developing process, and conversely, the solubility with respect to the developing solution of a resist film increases as it approaches the surface on the opposite side to an exposure surface. In this way, it is possible to form a resist having an inversely tapered resist pattern.

And in this invention, the content rate of the compound (c) in a resin composition was made into more than 1.0 mass part with respect to 100 mass parts of alkali-soluble resin (a). Such a content rate is higher than the content rate conventionally employ|adopted with respect to the compound which absorbs actinic radiation. In the resin composition, it is conjectured that by containing the compound (c) in such a high content ratio, the difference between the amount of crosslinking in the vicinity of the exposed surface and the amount of crosslinking in the surface on the opposite side to the exposed surface can be enlarged. . In other words, the angle formed by the sidewall constituting the reverse taper shape of the resist pattern with respect to the resist surface is sharpened, and a favorable reverse taper shape can be formed. And, if the crosslinking formation in the vicinity of the exposed surface of the resist is stronger than that at the bottom of the resist, even when the resist is placed in a high-temperature environment, the resist near the exposed surface where crosslinking formation is stronger than the heat effect at the bottom of the resist Since it is possible to compensate by In addition, since the resist formed using the resin composition has a stronger crosslinked structure in the vicinity of the exposed surface of the resist compared to the crosslinked structure in the vicinity of the resist bottom, deformation occurring in the vicinity of the resist bottom under a high temperature environment is reduced in the vicinity of the exposed surface. It is speculated that it is possible to compensate by the resist of

In addition, in this specification, "the angle formed by the side wall with respect to the resist surface" means the angle of the acute angle side formed between the side wall which forms an inverse taper structure, and the resist surface.

[[Alkali-soluble resin (a)]]

It does not specifically limit as alkali-soluble resin, An alkali-soluble resin which can be generally used for formation of a resist can be used. In this specification, "alkali-soluble resin" is a developing solution used in the developing process process of the negative photosensitive resin composition containing the said component, Especially preferably, it is resin which has solubility with respect to an alkali developing solution. On the other hand, "it has solubility with respect to an alkali developing solution" means that, when an alkali developing solution and a resin solution are mixed, a visually transparent mixed solution is obtained. More specifically, in this specification, when it melt|dissolves in the solution of pH 8 or more, "alkali solubility" means resin whose insoluble fraction is less than 0.1 mass %. For example, alkali-soluble resins include novolac resins, polyvinylphenol resins, polyvinyl alcohol resins, resol resins, acrylic resins, styrene-acrylic acid copolymer resins, hydroxystyrene polymer resins, and polyvinylhydroxybenzoate. , and mixed resins thereof. Especially, it is preferable to use a novolak resin individually or in mixture with other resin.

-Novolac resin-

As the novolac resin, a commercially available novolac resin or, for example, a novolac resin obtained by reacting phenols with aldehydes or ketones in the presence of an acidic catalyst (eg, oxalic acid) can be used.

Examples of the phenols include phenol, orthocresol, methacresol, paracresol, 2,3-dimethylphenol, 2,5-dimethylphenol, 3,4-dimethylphenol, 3,5-dimethylphenol, 2,4 -Dimethylphenol, 2,6-dimethylphenol, 2,3,5-trimethylphenol, 2,3,6-trimethylphenol, 2-t-butylphenol, 3-t-butylphenol, 4-t-butylphenol, 2-methylresorcinol, 4-methylresorcinol, 5-methylresorcinol, 4-t-butylcatechol, 2-methoxyphenol, 3-methoxyphenol, 2-propylphenol, 3-propylphenol , 4-propylphenol, 2-isopropylphenol, 2-methoxy-5-methylphenol, 2-t-butyl-5-methylphenol, thymol, isothymol, etc. are mentioned. These can be used individually or in combination of 2 or more types, respectively.

The aldehydes include, for example, formaldehyde, formalin, paraformaldehyde, trioxane, acetaldehyde, propylaldehyde, benzaldehyde, phenylacetaldehyde, α-phenylpropylaldehyde, β-phenylpropylaldehyde, o-hydroxybenzaldehyde , m-hydroxybenzaldehyde, p-hydroxybenzaldehyde, o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, p-ethylbenzaldehyde, p-n- Butylbenzaldehyde, terephthalaldehyde, etc. are mentioned. As ketones, acetone, methyl ethyl ketone, diethyl ketone, diphenyl ketone, etc. are mentioned. These can be used individually or in combination of 2 or more types, respectively.

Among the above-mentioned, it is preferable to use methacresol and paracresol together, to make these and formaldehyde, formalin, or paraformaldehyde condensation-react, and to prepare a novolak resin. This is because it is easy to control the molecular weight distribution of the polymer constituting the novolak resin, and thus the sensitivity of the resist can be easily controlled. The input ratio of methacresol and paracresol is 80:20-20:80 normally, preferably 70:30-40:60 on a mass basis.

On the other hand, the average molecular weight of the novolak resin is a weight average molecular weight in terms of monodisperse polystyrene measured by Gel Permeation Chromatography (GPC), and is usually 1000 or more, preferably 2000 or more, and more preferably 2500 or more. As mentioned above, it is 10000 or less normally, Preferably it is 7000 or less, More preferably, it is 6000 or less. When the weight average molecular weight of the novolak resin is less than the above lower limit, even if a crosslinking reaction occurs in the exposed portion, the molecular weight increase effect is small, and it becomes easy to melt|dissolve with respect to a developing solution. When the weight average molecular weight of the novolak resin exceeds the upper limit, the difference in solubility between the exposed and unexposed portions in the resist becomes small, and it becomes difficult to obtain a good resist pattern.

-Polyvinylphenol resin-

As polyvinylphenol resin, the homopolymer of vinylphenol, the copolymer of vinylphenol, and the monomer copolymerizable with this, etc. are mentioned, for example. As a monomer copolymerizable with a vinyl phenol resin, isopropenyl phenol, acrylic acid, methacrylic acid, styrene, maleic anhydride, maleic acid imide, and vinyl acetate are mentioned, for example. As polyvinylphenol resin, the homopolymer of vinylphenol is preferable and the homopolymer of p-vinylphenol is more preferable.

The average molecular weight of the polyvinylphenol resin is a weight average molecular weight (Mw) in terms of monodisperse polystyrene measured by GPC, and is usually 1000 or more, preferably 1500 or more, more preferably 2000 or more, usually 20000 or less, preferably is 10000 or less, more preferably 15000 or less. When the weight average molecular weight of the polyvinyl phenol resin is equal to or greater than the lower limit, a sufficient molecular weight increase effect can be obtained when a crosslinking reaction occurs in the exposed portion of the resist film, and the insolubility of the exposed portion to the developer can be sufficiently increased. When the weight average molecular weight of polyvinylphenol is below the said upper limit, the difference in solubility with respect to the alkali developing solution of the exposed part and unexposed part in a resist can fully be ensured and a favorable resist pattern can be obtained.

-Method for controlling the weight average molecular weight of each resin-

The weight average molecular weight of the novolac resin and the polyvinylphenol resin can be controlled within a desired range by adjusting the synthesis conditions. For example, the weight average molecular weight of each resin can be adjusted by adjusting the addition amount of the reaction raw material added at the time of manufacture of a novolak resin or polyvinyl phenol resin. More specifically, by increasing the compounding amount of formaldehyde, formalin, or paraformaldehyde added for the condensation reaction, the weight average molecular weight of the obtained novolak resin can be increased. Moreover, for example, by reducing the quantity of the polymerization initiator added at the time of superposition|polymerization of a polyvinyl phenol resin, the weight average molecular weight of the polyvinyl phenol resin obtained can be enlarged. Furthermore, for example, also by lengthening the reaction time at the time of the synthesis|combination of a novolak resin or polyvinylphenol resin, the weight average molecular weight of each resin obtained can be enlarged.

In addition, for example, (1) a method of pulverizing a resin obtained by synthesis or a commercially available resin and solid-liquid extraction with an organic solvent having an appropriate solubility, (2) a resin obtained by synthesis or a commercially available resin The weight average molecular weight can be controlled by the method of dissolving in a good solvent and dripping in a poor solvent, or dripping a poor solvent and performing solid-liquid or liquid-liquid extraction.

[[Crosslinking component (b)]]

A crosslinking component is a component which bridge|crosslinks alkali-soluble resin (a) by irradiation of actinic radiation, or irradiation of actinic radiation, and subsequent heat processing. By the action of this crosslinking component, a crosslinked structure is formed in the exposed region of the resist, so that the molecular weight of the alkali-soluble resin in the exposed region is increased, and the dissolution rate in the alkali developer is extremely reduced. Thereby, the resin composition functions as a negative resist material that can be developed with an alkali developer.

The crosslinking component (b) is a compound that generates an acid upon irradiation with actinic radiation (hereinafter also referred to as a “photoacid generator”) and a compound that crosslinks an alkali-soluble resin using an acid generated by light as a catalyst (acid subtraction) Substance: Hereinafter, also referred to as "acid crosslinking agent"). All of these compounds are excellent in compatibility with alkali-soluble resins, and they are preferable from the viewpoint of providing a crosslinkable chemically amplified resist with good sensitivity by combining with alkali-soluble resins.

[[[Mining generator]]]

The photoacid generator, which is a compound that generates an acid by actinic radiation, is not particularly limited as long as it is a substance that generates a Bronsted acid or a Lewis acid when irradiated with actinic radiation, onium salts, halogenated organic compounds, quinonediazide compounds, A well-known thing, such as a sulfone compound, an organic acid ester compound, an organic acid amide compound, and an organic acid imide compound, can be used. It is preferable to select these photo-acid generators from the point of spectral sensitivity according to the wavelength of the light source which exposes a pattern.

Examples of the onium salt include iodonium salts such as diazonium salts, ammonium salts and diphenyliodonium triflate, sulfonium salts such as triphenylsulfonium triflate, phosphonium salts, arsonium salts, and oxonium salts.

Examples of the halogenated organic compound include halogen-containing oxadiazole-based compounds, halogen-containing triazine-based compounds, halogen-containing acetophenone-based compounds, halogen-containing benzophenone-based compounds, halogen-containing sulfoxide-based compounds, halogen-containing sulfone-based compounds, and halogen-containing thiazole-based compounds. compounds, halogen-containing oxazole compounds, halogen-containing triazole compounds, halogen-containing 2-pyrron compounds, other halogen-containing heterocyclic compounds, halogen-containing aliphatic hydrocarbon compounds, halogen-containing aromatic hydrocarbon compounds, sulfenyl halide compounds, etc. can

Specific examples of the halogenated organic compound include tris(2,3-dibromopropyl)phosphate, tris(2,3-dibromo-3-chloropropyl)phosphate, tetrabromochlorobutane, 2-[2- (3,4-dimethoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-S-triazine, 2-[2-(4-methoxyphenyl)ethenyl]-4,6-bis (trichloromethyl)-S-triazine, hexachlorobenzene, hexabromobenzene, hexabromocyclododecane, hexabromocyclododecene, hexabromobiphenyl, allyltribromophenyl ether, tetrachlorobisphenol A , tetrabromobisphenol A, bis(chloroethyl)ether of tetrachlorobisphenol A, bis(bromoethyl)ether of tetrabromobisphenol A, bis(2,3-dichloropropyl)ether of bisphenol A, bisphenol A Bis(2,3-dibromopropyl)ether, tetrachlorobisphenol A bis(2,3-dichloropropyl)ether, tetrabromobisphenol A bis(2,3-dibromopropyl)ether, tetrachloro Bisphenol S, tetrabromobisphenol S, bis(chloroethyl)ether of tetrachlorobisphenol S, bis(bromoethyl)ether of tetrabromobisphenol S, bis(2,3-dichloropropyl)ether of bisphenol S, bisphenol Bis(2,3-dibromopropyl)ether of S, tris(2,3-dibromopropyl)isocyanurate, 2,2-bis(4-hydroxy-3,5-dibromophenyl ) halogen-based flame retardants such as propane and 2,2-bis(4-(2-hydroxyethoxy)-3,5-dibromophenyl)propane; etc. are exemplified.

Specific examples of the quinonediazide compound include 1,2-benzoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-5 -sulfonic acid esters of quinonediazide derivatives such as sulfonic acid ester, 2,1-naphthoquinonediazide-4-sulfonic acid ester, and 2,1-benzoquinonediazide-5-sulfonic acid ester; 1,2-benzoquinone-2-diazide-4-sulfonic acid chloride, 1,2-naphthoquinone-2-diazide-4-sulfonic acid chloride, 1,2-naphthoquinone-2-diazide-5- sulfonic acid chlorides of quinonediazide derivatives such as sulfonic acid chloride, 1,2-naphthoquinone-1-diazide-6-sulfonic acid chloride, and 1,2-benzoquinone-1-diazide-5-sulfonic acid chloride; and the like.

Specific examples of the sulfone compound include sulfone compounds and disulfone compounds having an unsubstituted, symmetrically or asymmetrically substituted alkyl group, alkenyl group, aralkyl group, aromatic group, or heterocyclic group.

Examples of organic acid esters include carboxylic acid esters, sulfonic acid esters, and phosphoric acid esters. Examples of organic acid amides include carboxylic acid amides, sulfonic acid amides, and phosphoric acid amides. Examples of organic acid imides include carboxylic acids imide, sulfonic acid imide, phosphoric acid imide, and the like.

In addition, cyclohexylmethyl (2-oxocyclohexyl) sulfonium trifluoromethanesulfonate, dicyclohexyl (2-oxocyclohexyl) sulfonium trifluoromethanesulfonate, 2-oxocyclohexyl (2-nor Bornyl) sulfonium trifluoromethanesulfonate, 2-cyclohexylsulfonylcyclohexanone, dimethyl (2-oxocyclohexyl)sulfonium trifluoromethanesulfonate, triphenylsulfonium trifluoromethanesulfonate, Diphenyliodonium trifluoromethanesulfonate, N-hydroxysucciimide trifluoromethanesulfonate, phenylparatoluenesulfonate, etc. are mentioned.

A photo-acid generator is 0.1-10 mass parts normally with respect to 100 mass parts of alkali-soluble resin (a), Preferably it is 0.3-8 mass parts, More preferably, it is used in the ratio of 0.5-5 mass parts. When the ratio of the photo-acid generator is too small or too large, the shape of the resist pattern may be deteriorated.

[[[acid crosslinking agent]]]

An acid crosslinking agent is a compound (acid subtraction substance) which can bridge|crosslink alkali-soluble resin in presence of the acid which generate|occur|produced by irradiation (exposure) of actinic radiation. As such an acid crosslinking agent, well-known acid crosslinking compounds, such as an alkoxymethylation urea resin, an alkoxymethylation melamine resin, an alkoxymethylation uron resin, an alkoxymethylation glycoluril resin, and an alkoxymethylation amino resin, are mentioned, for example.

In addition, as an acid crosslinking agent, alkyl etherified melamine resin, benzoguanamine resin, alkyletherified benzoguanamine resin, urea resin, alkyletherified urea resin, urethane-formaldehyde resin, resol type phenol formaldehyde resin, alkyl ether A pyrazole type phenol formaldehyde resin, an epoxy resin, etc. are mentioned.

On the other hand, it is preferable that an acid crosslinking agent is resin with a weight average molecular weight of 300 or more.

Among these, alkoxymethylated melamine resin is preferable, and specific examples thereof include methoxymethylated melamine resin, ethoxymethylated melamine resin, n-propoxymethylated melamine resin, and n-butoxymethylated melamine resin. Among these, methoxymethylated melamine resins, such as a hexamethoxymethylmelamine, are especially preferable at a point with a good resolution. Commercially available alkoxymethylated melamine resins include, for example, PL-1170, PL-1174, UFR65, CYMEL (registered trademark) 300, CYMEL (registered trademark) 303 (above, manufactured by Mitsui Cytec), BX-4000, and Nika Lock MW-30 and MX290 (above, the Sanwa Chemical company make) are mentioned.

These acid crosslinking agents can be used individually or in combination of 2 or more type, respectively. An acid crosslinking agent is 0.5-60 mass parts normally with respect to 100 mass parts of alkali-soluble resin (a), Preferably it is 1-50 mass parts, It is preferable to mix|blend in the ratio of 2-40 mass parts more preferably. If the blending amount of the acid crosslinking agent is equal to or greater than the lower limit, the crosslinking reaction can proceed sufficiently to avoid a decrease in the residual film ratio of the resist pattern after development using an alkali developer or the occurrence of deformation such as swelling or meandering of the resist pattern. have. If the compounding quantity of an acid crosslinking agent is below the said upper limit, the resist pattern obtained can be made high resolution.

[[Compound (c) that absorbs actinic radiation]]

The compound (c) that absorbs actinic radiation absorbs actinic radiation irradiated to the resist film. Thereby, a reverse-tapered resist pattern can be formed. In addition, the shape of the resist pattern can also be affected when actinic radiation irradiated to the resist film passes through the resist film and is reflected by a substrate or an ITO film formed on the substrate or the like. Accordingly, when the compound (c) contained in the resin composition absorbs the reflected actinic radiation, the shape of the resist pattern can be favorably controlled. In particular, a resin composition using a combination of a photoacid generator and an acid crosslinking agent as a crosslinking component is a crosslinking type chemically amplified resist, in which the acid generated by irradiation with light diffuses in the resist film to cause a crosslinking reaction to a region where light does not reach. For this reason, the shape of a resist pattern can be favorably controlled by making the compound (c) which absorbs actinic radiation exist.

On the other hand, in this specification, "absorbing actinic radiation" means having at least one maximum absorption wavelength λmax in any one of the wavelength ranges of 13.5 nm or more and 450 nm.

Examples of the compound (c) that absorbs actinic radiation include natural compounds such as bisazide compounds, azo dyes, methine dyes, azomethine dyes, curcumin and xanthone, cyanovinylstyrene compounds, 1-cyano -2-(4-dialkylaminophenyl)ethylene, p-(halogen-substituted phenylazo)-dialkylaminobenzene, 1-alkoxy-4-(4'-N,N-dialkylaminophenylazo)benzene Liu, dialkylamino compound, 1,2-dicyanoethylene, 9-cyanoanthracene, 9-anthrylmethylenemalononitrile, N-ethyl-3-carbazolylmethylenemalononitrile, 2-(3,3 -dicyano-2-propenylidene)-3-methyl-1,3-thiazoline etc. are mentioned. These can be used individually by 1 type or in mixture of multiple types. Especially, it is preferable to use the bisazide compound which has an azide group at both terminals as a compound (c). Moreover, it is preferable to use what absorbs actinic radiation in the area|region of wavelength 200-500 nm especially as a bisazide compound.

As the bisazide compound, for example, 4,4'-diadochalcone, 2,6-bis(4'-azidobenzal)cyclohexanone, 2,6-bis(4'-azidobenzal) -4-methylcyclohexanone, 2,6-bis(4'-azidobenzal)-4-ethylcyclohexanone, 4,4'-diazostilbene-2,2'-sodium disulfonate, 4, 4'- diazidodiphenyl sulfide, 4,4'- diazido benzophenone, 4,4'- diazidodiphenyl, 2,7- diazidofluorene, 4,4'- diazidophenylmethane can

-Content of compound (c) that absorbs actinic radiation-

The resin composition contains more than 1 mass part of compound (c) with respect to 100 mass parts of alkali-soluble resin (a), Preferably it contains 1.2 mass parts or more, More preferably, it contains 1.5 mass parts or more, Preferably it contains 1.8 mass parts or more, Usually, 10.0 mass parts or less, Preferably it is 8.0 mass parts or less, More preferably, it contains 5.0 mass parts or less, More preferably, it contains 3.5 mass parts or less. When the compounding amount of the compound (c) in the resin composition is more than 1 part by mass with respect to 100 parts by mass of the alkali-soluble resin (a), a resist pattern having a favorable reverse taper shape is formed in a resist formed using such a resin composition. At the same time, it is possible to maintain such a good reverse taper shape even under a high temperature environment. Moreover, by making the compounding quantity of compound (c) into below the said upper limit, the heat resistance of the resist formed using the resin composition can be improved further. In general, when the resist film thickness is thick, the actinic radiation hardly penetrates the resist film, so the compounding amount of the compound (c) is relatively small, and when the resist film is thin, it is preferable to use a relatively large amount.

[[Basic compound]]

Preferably, a basic compound is mix|blended with respect to a resin composition. In this specification, a basic compound means the compound which can capture|acquire the acid derived from a photo-acid generator. It is because the temperature permissible range (PEB temperature margin) of the heat processing temperature in a 2nd heat processing process can be expanded while improving the storage stability of a resin composition when a basic compound is mix|blended. By extending the temperature tolerance of the heat treatment temperature in the second heat treatment step, it is possible to suppress the manufacturing variation of the resist pattern, so that the flexibility of the resist pattern forming method of the present invention can be increased. As a basic compound (d), an inorganic basic compound and an organic basic compound are mentioned. Formation of a resist using a resin composition WHEREIN: From the high solubility to an organic solvent, an organic basic compound is more preferable. It is because the uniformity of the coating film formed by apply|coating the resin composition solution on a board|substrate can be improved. Examples of the organic basic compound include a nitrogen-containing basic compound, an organic halide, an alkoxide, a phosphazene derivative, and a Verkade base. Especially, it is preferable to use a nitrogen-containing basic compound as a basic compound. It is because the storage stability of a resin composition can be improved.

Examples of the nitrogen-containing basic compound include aliphatic primary amines, aliphatic secondary amines, aliphatic tertiary amines, amino alcohols, aromatic amines, quaternary ammonium hydroxides, and alicyclic amines. Preferably, as a nitrogen-containing basic compound, an aliphatic primary amine, an aliphatic secondary amine, and an aliphatic tertiary amine are mix|blended. Specific examples of the nitrogen-containing basic compound include butylamine, hexylamine, ethanolamine, diethanolamine, triethanolamine, 2-ethylhexylamine, 2-ethylhexyloxypropylamine, methoxypropylamine, and diethylaminopropylamine. , N-methylaniline, N-ethylaniline, N-propylaniline, dimethyl-N-methylaniline, diethyl-N-methylaniline, diisopropyl-N-dimethylaniline, N-methylaminophenol, N-ethylamino Phenol, N,N-dimethylaniline, N,N-diethylaniline, N,N-dimethylaminophenol, tetrabutylammonium hydroxide, tetramethylammonium hydroxide, 1,8-diazabicyclo[5.4.0 ]undeca-7-ene, 1,5-diazabicyclo[4.3.0]non-5-ene, and the like. Especially, triethanolamine is preferable.

-Property of basic compound (d)-

Moreover, as a basic compound (d), a basic compound with a comparatively high boiling point is preferable. Specifically, the basic compound (d) preferably has a boiling point of 60°C or higher, more preferably 100°C or higher, still more preferably 150°C or higher, and usually 500°C or lower. When the boiling point of the basic compound (d) is high, volatilization in the first heat treatment step or the second heat treatment step described later is reduced, and the residual amount of the basic compound (d) in the obtained resist film after the post-exposure bake step is completed, It becomes the quantity close|similar to the compounding ratio of the basic compound (d) in a resin composition. Thereby, the acid neutralization effect of the basic compound (d) as designed at the time of preparing the resin composition is exhibited in the actual resist, the crosslinking reaction is suppressed from proceeding excessively, and the resist pattern becomes thick. It can be effectively suppressed as designed. In view of these effects, the boiling point of the basic compound is the heat treatment temperature in the first heat treatment step (hereinafter also referred to as “pre-bake temperature”) and the heat treatment temperature in the second heat treatment step (hereinafter “post-exposure bake”). temperature"), preferably 10°C or higher, more preferably 30°C or higher, and still more preferably 50°C or higher.

Moreover, it is preferable that a basic compound is a compound with a weight average molecular weight of less than 300.

-Amount of basic compound (d) blended (based on 100 parts by mass of alkali-soluble resin (a))-

The resin composition contains the basic compound (d) with respect to 100 parts by mass of the alkali-soluble resin (a), usually 0.001 to 10 parts by mass, preferably 0.005 to 8 parts by mass, more preferably 0.01 to 5 parts by mass. can When content of a basic compound (d) is more than the said lower limit, while improving the storage stability of a resin composition, PEB temperature margin can be expanded. Moreover, when the content of the basic compound (d) exceeds the upper limit, the effect of improving storage stability is saturated and there is a possibility that the resist properties are adversely affected.

-Amount of basic compound (d) (based on photoacid generator)-

Moreover, as for the compounding quantity of the basic compound (d) in the resin composition, on a mass basis, 0.001 times or more of the compounding quantity of a photo-acid generator is preferable, 0.050 times or more are more preferable, 0.200 times or more are still more preferable, 3.500 Less than twice is preferable, less than 2.000 times is more preferable, and less than 0.500 times is still more preferable. By blending the basic compound (d) with the photo-acid generator in a ratio equal to or higher than the lower limit, the allowable range of the PEB temperature margin can be expanded. Moreover, by making the compounding quantity of a basic compound (d) into below the said upper limit, neutralizing the acid which generate|occur|produced by exposure excessively and inhibiting advancing of a crosslinking reaction can be avoided. Thereby, the reverse taper shape of the resist pattern formed using the resin composition can be made favorable. Moreover, by making the compounding quantity of a basic compound (d) below the said upper limit, the sensitivity of the resist formed using the resin composition can be improved.

[[Other Additives]]

To the resin composition, optionally, a surfactant may be added. As surfactant, For example, polyoxyethylene alkyl ethers, such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene aryl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenol ether; polyethylene glycol dialkyl esters such as polyethylene glycol dilaurate and ethylene glycol distearate; EFTOP EF301, EF303, EF352 (manufactured by Shin-Akita Chemical), Megafax F171, F172, F173, F177 (manufactured by Dainippon Ink), Florado FC430, FC431 (manufactured by Sumitomo 3M), Asahi Guard AG710, Sufflon Fluorine surfactants, such as S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (made by Asahi Glass Corporation); organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.); and acrylic acid-based or methacrylic acid-based (co)polymer polyflow No.75 and No.95 (manufactured by Kyoeisha Oil and Chemical Industries, Ltd.). The compounding quantity of these surfactant is 2 mass parts or less normally per 100 mass parts of solid content of a resin composition, Preferably it is 1 mass part or less.

[solvent]

It is preferable to use an organic solvent as a solvent in which each component mentioned above is dissolved. The organic solvent is used in a sufficient amount because it can uniformly dissolve or disperse each component as described above. Solid content concentration in a resin composition solution is 5-50 mass % normally, Preferably it is about 10-40 mass %.

Examples of the organic solvent include alcohols such as n-propyl alcohol, i-propyl alcohol, n-butyl alcohol and cyclohexyl alcohol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone; esters such as propyl formate, butyl formate, ethyl acetate, propyl acetate, butyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, methyl lactate, ethyl lactate, ethyl ethoxypropionate, and ethyl pyruvate; cyclic ethers such as tetrahydrofuran and dioxane; cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; cellosolve acetates such as ethyl cellosolve acetate, propyl cellosolve acetate, and butyl cellosolve acetate; alcohol ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether; propylene glycols such as propylene glycol, propylene glycol monomethyl ether acetate, propylene glycol monoethyl acetate, and propylene glycol monobutyl ether; diethylene glycols such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether; lactones such as γ-butyrolactone; halogenated hydrocarbons such as trichloroethylene; aromatic hydrocarbons such as toluene and xylene; Polar organic solvents, such as dimethylacetamide, dimethylformamide, and N-methylacetamide; These two or more types of mixed solvents, etc. are mentioned.

<Applying process>

In an application|coating process, the resin composition obtained by the preparation process is apply|coated and dried on a board|substrate, and a coating film is formed. The substrate is not particularly limited as long as it is a general substrate that can be used as a semiconductor substrate, and may be, for example, a silicon substrate, a glass substrate, an ITO film-forming substrate, a chromium film-forming substrate, or a resin substrate. In addition, as a coating method, the method of apply|coating by spin coating, spraying, brush coating, etc., and general coating methods, such as dip coating, are employable.

<First heat treatment step>

In a 1st heat treatment process, the coating film formed in the application|coating process is heated at 1st temperature. Here, it is preferable that the pre-bake temperature which is 1st temperature is higher than the post-bake temperature which is 2nd temperature, It is more preferable that it is 5 degreeC or more, and it is more preferable that it is 10 degreeC or more high. When the pre-bake temperature is higher than the post-bake temperature, the reverse taper shape of the resulting resist pattern can be made still more favorable, and such a good reverse taper shape can be maintained even more favorably in a high-temperature environment. On the other hand, as for the prebaking temperature which is 1st temperature, 80 degreeC or more is preferable, 100 degreeC or more is more preferable, 105 degreeC or more is still more preferable, 130 degrees C or less is preferable, and 125 degrees C or less is more preferable. In addition, the time of the first heat treatment process may be 10 seconds or more and 200 seconds or less. In addition, the 1st heat treatment process is not specifically limited, It can be implemented by mounting the board|substrate with which the coating film was formed on heating mechanisms, such as a hotplate with which a general baking apparatus was equipped, The prebaking temperature is the set temperature of a hotplate. You can control it by changing it. And the film thickness of the resist film obtained through the 1st heat processing process is 0.1 micrometer or more and 15 micrometers or less normally.

<Exposure process>

In the exposure step, the resist film obtained through the first heat treatment step is irradiated with actinic radiation. The actinic radiation has a wavelength of 13.5 nm or more and 450 nm or less, and specific examples thereof include ultraviolet rays, far ultraviolet rays, excimer laser beams, X-rays, electron beams, and extreme ultraviolet rays. The exposure light source is not particularly limited as long as it is a light source capable of irradiating actinic radiation, and for example, an ultraviolet light source, a semiconductor laser irradiation device, a metal halide lamp, a high-pressure mercury lamp, an excimer laser (KrF, ArF, F2) irradiation device, An X-ray exposure apparatus, an electron beam exposure apparatus, an EUV exposure apparatus, etc. are mentioned.

And exposure amount is 10 mJ/cm< ² > or more and 2000 mJ/cm< ² > or less normally, and exposure time is 1 second or more and 180 second or less normally.

<Second heat treatment process>

In the second heat treatment step, the resist film after the start of the exposure step is maintained under the second temperature condition. Specifically, the second heat treatment step may be started before the exposure step is completed, as long as it is after the start of the exposure step, or may be started after the exposure step is completed. The second heat treatment step can be performed by the same apparatus as the first heat treatment step. However, when the second heat treatment step is started before the exposure step is completed, it is preferable that the sample stage of the exposure device has a hot plate type function. do. The second temperature may be equal to or lower than the first temperature, preferably 20°C or higher, more preferably 80°C or higher, usually 130°C or lower, preferably 120°C or lower, and more preferably 115°C or lower. Moreover, the time of a 2nd heat processing process is 10 second or more normally, Preferably it is 60 second or more, More preferably, it is 100 second or more, and is 200 second or less normally. In the second heat treatment step, the crosslinking reaction of the crosslinking component (b) can be accelerated by maintaining the resist film that has undergone the exposure step under the second temperature condition. On the other hand, in the case of employing a combination of an alkali-soluble resin (a) and a crosslinking component (b) in which a sufficient crosslinking reaction occurs only by irradiation with actinic radiation, in the second heat treatment step, the resist film is not "heated", but at about room temperature ( For example, you may hold|maintain for predetermined time in the atmosphere of 25 degreeC).

<Development process>

Using an alkali developer, the resist pattern is developed by general development methods such as paddle development, spray development, and dip development. The alkali developer used in the developing step may be an aqueous alkali solution having a pH of 8 or higher. Examples of the alkali include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium silicate and ammonia; primary amines such as ethylamine and propylamine; secondary amines such as diethylamine and dipropylamine; tertiary amines such as trimethylamine and triethylamine; alcohol amines such as diethylethanolamine and triethanolamine; quaternary ammonium hydroxides such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, triethylhydroxymethylammonium hydroxide, and trimethylhydroxyethylammonium hydroxide; and the like. Moreover, water-soluble organic solvents, such as methyl alcohol, ethyl alcohol, propyl alcohol, and ethylene glycol, surfactant, resin dissolution inhibitor, etc. can be added to aqueous alkali solution as needed.

And when the resist pattern obtained through the developing process is used for the lift-off method, metal wiring material is vapor-deposited with respect to the board|substrate whole surface from it, and various films, such as a metal vapor deposition film, are formed. Thereafter, the resist pattern is removed together with the film formed thereon, leaving a film such as a metal vapor deposition film formed on the substrate. When manufacturing an organic electroluminescent display element, organic electroluminescent material is vapor-deposited on the resist pattern obtained by image development, and metals, such as aluminum, are then vapor-deposited. In this case, the resist pattern is left without being removed.

(Resist)

The resist of the present invention comprises an alkali-soluble resin (a), a crosslinking component (b) that crosslinks an alkali-soluble resin by irradiation with actinic radiation or irradiation with actinic radiation and subsequent heat treatment, and a compound that absorbs actinic radiation ( A radiation-sensitive resin composition containing c), wherein (1) the crosslinking component (b) uses a compound that generates an acid upon irradiation with actinic radiation, and an acid generated with actinic radiation as a catalyst, an alkali-soluble resin (a) ) is a combination of a compound that cross-links, (2) a compound (c) that absorbs actinic radiation, with respect to 100 parts by mass of the alkali-soluble resin (a), containing more than 1.0 parts by mass, using a radiation-sensitive resin composition In the case of forming a resist pattern having an inversely tapered cross section comprising lines and spaces, the ratio Wb/Wt of the line width Wt on the exposed surface to the line width Wb on the non-exposed surface is less than 0.7; Preferably, it is less than 0.6, and the angle formed by the sidewall of the line constituting the reverse tapered shape of the resist pattern with respect to the resist surface after heating for 1 minute under a temperature condition of 120° C. is less than 90°. Such a resist, obtained by the resist pattern forming method of the present invention, has a sufficiently large taper angle, and has a resist pattern capable of maintaining a good reverse taper shape even when placed in a high-temperature environment. And, such a resist contains at least an alkali-soluble resin (a), a crosslinking component (b), and a compound (c) that absorbs actinic radiation, and optionally contains a basic compound (d) and other components. . On the other hand, each component contained in the resist is contained in the said radiation-sensitive resin composition, and their suitable abundance ratio is the same as the suitable abundance ratio of each component in the resin composition. Moreover, in a resist, alkali-soluble resin (a) exists in the mutually crosslinked state. When the resist of the present invention is used to form a wiring pattern, it is possible to favorably form a fine wiring pattern. In addition, since the resist of the present invention has excellent heat resistance, it can maintain a tapered shape even when the resist pattern is heated. A fine wiring pattern can be favorably formed.

Example

Hereinafter, the present invention will be specifically described based on Examples, but the present invention is not limited to these Examples. In addition, in the following description, "%" and "part" which show quantity are a mass basis, unless there is particular notice.

In Examples and Comparative Examples, the reverse taper shape and heat resistance of the resist were measured and evaluated as follows, respectively. In addition, the measurement conditions of the weight average molecular weight of alkali-soluble resin used for the Example and the comparative example were carried out as follows.

<Reverse taper shape>

With respect to the resist pattern formed in Examples and Comparative Examples, which consists of lines (parts that remain undissolved after the development process) and spaces (parts where the resist film is dissolved and become voids in the developing process), the lower surface of the resist film (i.e., the substrate) side) and the line width (top line width) on the upper surface of the resist film were respectively measured under observation with a scanning electron microscope (SEM). The obtained bottom line|wire width was divided by the top line|wire width, and the following reference|standard evaluated. The larger the value of the bottom line width/top line width, the greater the difference between the lengths of the upper and lower sides of the inverted trapezoid of the line (the portion remaining undissolved after the development process), which means that the taper angle of the resist pattern is large.

A: The value of bottom line width/top line width is less than 0.6

B: The value of the bottom line width/top line width is 0.6 or more and less than 0.7

C: The value of bottom line width/top line width is 0.7 or more

<Heat resistance>

The board|substrate on which the resist pattern was formed by the Example and the comparative example was further heated at 120 degreeC for 1 minute on a hotplate. Thereafter, the cross-sectional shape of the substrate on which the resist pattern is formed is observed using SEM, the angle formed by the sidewall of the resist constituting the reverse tapered shape with respect to the surface of the resist is measured, and heat resistance is evaluated according to the following criteria. did According to this evaluation method, it can evaluate that the favorable reverse taper shape with a sufficiently large taper angle was maintained after heating further after the image development process. That is, even when the formed resist pattern is subjected to, for example, a vapor deposition process of a metal wiring material and the like and heated, it can be evaluated whether a favorable reverse taper shape can be maintained.

A: The angle the side wall makes with respect to the resist surface is 70° or less

B: The angle formed by the sidewall with respect to the resist surface is greater than 70° and less than or equal to 80°

C: The angle formed by the sidewall with respect to the resist surface is greater than 80° and less than or equal to 90°

C: The angle the sidewall makes with respect to the resist surface exceeds 90°

<Measurement of Weight Average Molecular Weight>

-Condition-

Device: HLC-8120GPC (manufactured by Tosoh)

Column: TSKgel G5000HXL, inner diameter of 7.8 mm × length of 30 cm (manufactured by Tosoh) in two pieces

Temperature: 40℃

Solvent: tetrahydrofuran (THF)

Flow rate: 1.0 ml/min

Sample: 0.05 to 0.2 ml of a sample with a concentration of 0.05 to 0.1 mass% is injected

-Calibration curve-

Seven Toso monodisperse polystyrene standard samples with molecular weights of 5.0 × 10 ² , 2.5 × 10 ³ , 9.83 × 10 ³ , 3.72 × 10 ⁴ , 1.89 × 10 ⁵ , 7.07 × 10 ⁵ , and 1.11 × 10 ⁶ , respectively A molecular weight calibration curve prepared using

(Example 1)

<Preparation of the radiation-sensitive resin composition solution (preparation step)>

A novolac resin having a weight average molecular weight of 3000 obtained by dehydration condensation of 70 parts of m-cresol and 30 parts of p-cresol with 19 parts of formaldehyde was used as alkali-soluble resin (a).

100 parts of this alkali-soluble resin (a), 2 parts of a halogen-containing triazine-based photo-acid generator (Midori Chemical, trade name "TAZ110") as a cross-linking component (b), a melamine-based cross-linking agent (acid cross-linking agent: Mitsui Cytec, trade name " Cymel 303") 8 parts, and 2 parts of bisazide compound (Toyo Synthetic Industry make, trade name "BAC-M") as compound (c) which absorbs actinic radiation, propylene glycol monomethyl ether acetate (PGMEA) as an organic solvent ) was dissolved in 176 parts. The dispersion of the obtained radiation-sensitive resin composition was filtered through a polytetrafluoroethylene membrane filter having a pore diameter of 0.1 µm to prepare a radiation-sensitive resin composition solution having a solid content concentration of 39 mass%.

<Formation of resist pattern>

On a silicon wafer as a substrate, a radiation-sensitive resin composition solution was applied using a spin coater and dried to form a coating film (application step). Next, the silicon wafer which has a coating film on the surface was mounted on the hotplate set to 110 degreeC of 1st temperature (pre-bake temperature), and it hold|maintained for 90 second, and performed the 1st heat processing (pre-bake) process. The resulting resist film had a film thickness of 4 µm.

On this resist film, using a 20 µm line & space (L&S) pattern mask, it was exposed with a parallel light mask aligner (manufactured by Canon, trade name "PLA501F", ultraviolet light source, irradiation wavelength 365 nm to 436 nm). The exposure amount was an exposure amount in which the ratio of the width of the line portion to the width of the space portion was 1:1 (exposure step). After the exposure step, the second temperature (post-bake temperature) was set to 100° C., the silicon wafer with the resist film was placed on a hot plate, and held for 100 seconds to perform a second heat treatment (post-bake) step. After the second heat treatment step, paddle development was carried out for 70 seconds with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) to obtain an L&S resist pattern. The cross-sectional shape of the resist pattern was a reverse tapered shape. Table 1 shows the results of evaluation of the obtained resist pattern according to the method described above.

(Example 2)

A resist pattern was formed in the same manner as in Example 1 except that 0.5 parts of triethanolamine (TEOA) was further blended as the basic compound (d) in the preparation of the radiation-sensitive resin composition solution. Table 1 shows the results of evaluation of the obtained resist pattern according to the method described above.

(Examples 3-4)

Preparation of the radiation-sensitive resin composition solution WHEREIN: It carried out similarly to Example 1 except having changed the compounding quantity of the compound (c) which absorbs actinic radiation as shown in Table 1, and formed the resist pattern. Table 1 shows the results of evaluation of the obtained resist pattern according to the method described above.

(Examples 5 to 9)

In the formation of the resist pattern, the combinations of the first temperature in the first heat treatment (pre-bake) step and the second temperature in the second heat treatment (post-bake) step were changed as shown in Table 1, respectively. Except that, it carried out similarly to Example 1, and formed the resist pattern. Table 1 shows the results of evaluation of the obtained resist pattern according to the method described above.

(Comparative Examples 1-3)

In the formation of the resist pattern, in Example 1, except that the second temperature in the second heat treatment (post-bake) step was set higher than the first temperature in the first heat treatment (pre-bake) step, respectively. In the same manner, a resist pattern was formed. Table 1 shows the results of evaluation of the obtained resist pattern according to the method described above.

(Comparative Example 4)

In the formation of the resist pattern, the first temperature in the first heat treatment (pre-bake) step and the second temperature in the second heat treatment (post-bake) step are respectively set to the same temperature, and the actinic radiation A resist pattern was formed in the same manner as in Example 1, except that the compounding amount of the compound (c) that absorbs was changed to 1 part by mass. Table 1 shows the results of evaluation of the obtained resist pattern according to the method described above.

(Comparative Example 5)

In the formation of the resist pattern, the first temperature in the first heat treatment (pre-bake) step was set higher than the second temperature in the second heat treatment (post-bake) step, but the compound (c) that absorbs actinic radiation ) was changed to 1 part by mass. Except for this point, it carried out similarly to Example 1, and formed the resist pattern. Table 1 shows the results of evaluation of the obtained resist pattern according to the method described above.

From Table 1, as a radiation-sensitive resin composition containing an alkali-soluble resin (a), a photo-acid generator and an acid cross-linking agent as a cross-linking component (b), and a compound (c) absorbing actinic radiation, the compound (c), With respect to 100 parts by mass of the alkali-soluble resin (a), a resin composition containing more than 1.0 part by mass was used, and in Examples 1 to 9 in which the pre-bake temperature was higher than or equal to the post-bake temperature, a resist pattern having a favorable reverse tapered shape was formed. , it can be seen that a good reverse taper shape can be maintained even under a high temperature environment. On the other hand, it turns out that a favorable taper shape and heat resistance are incompatible in Comparative Examples 1-3 whose pre-bake temperature is less than the post-bake temperature, and Comparative Examples 4-5 whose content of a compound (c) is 1 mass part or less.

ADVANTAGE OF THE INVENTION According to this invention, the resist pattern excellent in the reverse taper shape and heat resistance can be formed.

Moreover, the resist of this invention has favorable reverse taper shape of a resist pattern, and is excellent in heat resistance.

Claims (3)

A preparation step of preparing the radiation-sensitive resin composition;
A coating step of applying and drying the radiation-sensitive resin composition on a substrate to form a coating film;
a first heat treatment process of heating the coating film at a first temperature;
an exposure step of irradiating actinic radiation to the resist film obtained through the first heat treatment step;
a second heat treatment step of maintaining the resist film under a second temperature condition after initiation of the exposure step;
The radiation-sensitive resin composition comprises an alkali-soluble resin (a), a crosslinking component (b) that crosslinks the alkali-soluble resin by irradiation with actinic radiation, or irradiation with actinic radiation and subsequent heat treatment, and the actinic radiation. A radiation-sensitive resin composition containing an absorbing compound (c), wherein (1) the crosslinking component (b) catalyzes a compound that generates an acid upon irradiation with the actinic radiation, and an acid generated with the actinic radiation is a combination of a compound that crosslinks the alkali-soluble resin (a), and (2) contains more than 1.0 part by mass of the compound (c) absorbing the actinic radiation with respect to 100 parts by mass of the alkali-soluble resin (a) and also,
The first temperature is higher than the second temperature, the resist pattern forming method. The method of claim 1,
The method for forming a resist pattern, wherein the radiation-sensitive resin composition further contains a basic compound (d). Contains an alkali-soluble resin (a), a crosslinking component (b) that crosslinks the alkali-soluble resin by irradiation with actinic radiation, or irradiation with actinic radiation and subsequent heat treatment, and a compound (c) that absorbs the actinic radiation A radiation-sensitive resin composition comprising: (1) the crosslinking component (b) comprises a compound that generates an acid upon irradiation with the actinic radiation, and an acid generated by the actinic radiation as a catalyst, the alkali-soluble resin (a) ) is a combination of a compound that cross-links, (2) the compound (c) absorbing the actinic radiation, with respect to 100 parts by mass of the alkali-soluble resin (a), containing more than 1.0 parts by mass, a radiation-sensitive resin composition As a resist pattern formed using
It is a resist pattern with a reverse tapered cross-section consisting of lines and spaces, wherein the ratio Wb/Wt of the line width Wt on the exposed surface to the line width Wb on the non-exposed surface is less than 0.7;
The resist pattern, wherein the angle formed by the sidewall of the line constituting the reverse tapered shape of the resist pattern with respect to the resist surface after heating for 1 minute under the temperature condition of 120°C is less than 90°.