Negative resist composition for gradation exposure

Abstract

To provide a negative resist composition for gradation exposure which allows alkaline development in pattern formation by irradiation with an electron beam, an ion beam, or EUV, is suitable for gradation exposure because the height of the convex portions can be easily controlled according to the amount of exposure, and is capable of forming a three-dimensional pattern with excellent resolution.SOLUTION: A chemical amplification type negative resist composition for gradation exposure comprises a phenolic compound (A) having a molecular weight of 400 to 2500, which has two or more phenolic hydroxyl groups per molecule and has two or more substituents of one or more kinds per molecule selected from the group consisting of hydroxymethyl groups and alkoxymethyl groups at the ortho-positions of the phenolic hydroxyl groups, and an organic basic compound (B), wherein the content of the phenolic compound (A) in the total solid content of the negative resist composition is 70 wt.% or more. The composition is substantially free of an acid generator.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a three-dimensional mold and a negative resist composition for tone exposure.

Background Art

[0002] In recent years, in the manufacture of semiconductor devices and display devices, due to the progress of lithography technology, pattern miniaturization has been rapidly advancing, and high resolution has been demanded. As a miniaturization technique, generally, the wavelength of the exposure light source is shortened. In addition to the currently used KrF excimer laser light, lithography using ArF, F2, EUV, X-rays, electron beams, and other charged particle beams as exposure light has been proposed.

[0003] In addition, a technique alternative to the conventional lithography technology has been explored. One example is a technique in which a mold is fabricated by electron beam irradiation and nanoimprint lithography is performed using the mold. In the nanoimprint lithography, a mold (die) having a pattern of nanometer size formed in advance is pressed against a resin material on a substrate to transfer the mold, thereby forming a fine uneven pattern. In nanoimprint lithography, the mold (die) is the most important in terms of determining the accuracy of the product. Therefore, a method for manufacturing a high-resolution mold is desired for the mold that is the master for nanoimprint lithography, and the development of a resist material having high resolution that can be used for the manufacture of the mold is desired.

[0004] Conventionally, for example, a microfabrication method by electron beam irradiation has been mainly used for fabricating a two-dimensional pattern having the same height or depth, such as a line and space, and there have been few examples of applying it to fabricating a three-dimensional mold pattern in which the height, depth, line width, etc. change. For example, Patent Document 1 discloses a method for manufacturing a three-dimensional mold, which includes an irradiation step of irradiating an electron beam onto a resist layer of a workpiece having a resist layer composed of an organopolysiloxane on a substrate, and a development step of developing the resist layer after the electron beam irradiation to form uneven portions on the resist layer. In the irradiation step, the method includes irradiating with an acceleration voltage such that primary electrons do not reach the substrate and secondary electrons reach the substrate. However, in the method for manufacturing a three-dimensional mold of Patent Document 1, since the sensitivity of the organopolysiloxane is low, there is a problem that a low acceleration voltage has to be used under an achievable exposure amount. Also, due to the low acceleration voltage, there are problems such as deterioration of resolution performance and that only thin-film resists can be handled.

[0005] As a resist material, for example, Patent Document 2 discloses a negative-tone photoresist that has high resolution and high sensitivity, is developable in water or an aqueous solution, and is not chemically amplified. The photoresist crosslinks polymer chains based on the rearrangement of carbon-oxygen bonds in pendant ester groups of polymers such as poly(methacrylic acid 2-methoxyethylethyl). However, when using such a polymer material having alkali developability and crosslinkability, swelling easily occurs during development, and since the molecular weight is large and the molecular weight distribution is wide, there is a limit to the reduction of resolution, and further development of a resist material suitable for tone exposure has been demanded.

[0006] Therefore, development of low-molecular materials has been carried out as an alkali-soluble resin serving as a resist substrate. The applicant of the present application discloses a negative resist composition containing a phenolic compound (A) having a molecular weight of 400 to 2500 and having two or more phenolic hydroxyl groups in one molecule and one or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group at the ortho position of the phenolic hydroxyl group, which is a chemically amplified or non-chemically amplified negative resist composition capable of obtaining a pattern with high line width stability after exposure in vacuum, high resolution, and low line edge roughness, and the content of the phenolic compound (A) in the total solid content of the negative resist composition is 70% by mass or more (Patent Document 3). However, Patent Document 3 does not describe at all performing tone exposure or forming an uneven pattern including at least one of a convex portion having different heights and a convex portion having an inclined surface. Moreover, the basic compound described in Patent Document 3 is merely described as a quencher for suppressing the diffusion of acid generated from an acid generator in a chemically amplified negative resist composition. There is no description at all about combining a basic compound with the phenolic compound (A) without using an acid generator in a non-chemically amplified negative resist composition.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0008] For a resist for manufacturing a three-dimensional pattern, an analog property is required to control the processing height (processing depth) according to the exposure dose, for example, an electron beam, that is, according to the grayscale exposure. However, although the conventional chemically amplified negative resist composition has been made highly sensitive by an acid generator, it is difficult to control the processing height according to the exposure dose and is not suitable for grayscale exposure. In addition, a resist material that has been conventionally known to easily control the processing height according to the exposure dose has a low resolution.

[0009] In view of the above circumstances, a first object of the present disclosure is to provide a method for manufacturing a three-dimensional mold having an uneven pattern shape including at least one of convex portions having different heights and convex portions having inclined surfaces with high resolution. A second object of the present disclosure is to be capable of alkali development in pattern formation by irradiation with an electron beam, an ion beam, or EUV, to easily control the height of a convex portion according to the magnitude of the exposure dose, to be suitable for grayscale exposure, and to provide a negative resist composition for grayscale exposure capable of forming a three-dimensional pattern with excellent resolution.

Means for Solving the Problems

[0010] One embodiment of the present disclosure is a method for manufacturing a three-dimensional mold having an uneven pattern shape including at least one of convex portions having different heights and convex portions having inclined surfaces, A negative resist composition containing a phenolic compound (A) having two or more phenolic hydroxyl groups in one molecule and two or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group at the ortho position of the phenolic hydroxyl group, and having a molecular weight of 400 to 2500, wherein the content of the phenolic compound (A) in the total solid content of the negative resist composition is 70% by weight or more and substantially does not contain an acid generator, and is a non-chemically amplified negative resist composition. After coating the negative resist composition on a substrate, a heat treatment is performed to form a resist film, and Provided is a method for manufacturing a three-dimensional mold, including a step of subjecting the resist film to gradation exposure and development.

[0011] In the method for manufacturing a three-dimensional mold of the present disclosure, it is preferable that the negative resist composition further contains an organic basic compound (B) because it becomes easier to precisely control the height of the convex portion in proportion to the amount of exposure, and the gradation exposure performance is improved. In the method for manufacturing a three-dimensional mold of the present disclosure, the organic basic compound (B) may be an organic basic compound containing a hydroxyl group.

[0012] In the method for manufacturing a three-dimensional mold of the present disclosure, the minimum adjacent convex portion interval of the convex portions may be 500 nm or less.

[0013] Another embodiment of the present disclosure provides a negative resist composition for gradation exposure, which contains a phenolic compound (A) having two or more phenolic hydroxyl groups in one molecule and two or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group at the ortho position of the phenolic hydroxyl group in one molecule, and having a molecular weight of 400 to 2500, and an organic basic compound (B), wherein the content of the phenolic compound (A) in the total solid content of the negative resist composition is 70% by weight or more, and which is a non-chemically amplified type that substantially does not contain an acid generator.

[0014] In the negative resist composition for gradation exposure of the present disclosure, the organic basic compound (B) may be an organic basic compound containing a hydroxyl group. In the negative resist composition for gradation exposure of the present disclosure, the organic basic compound (B) may have a molecular weight of less than 400.

Advantages of the Invention

[0015] According to the present disclosure, it is possible to provide a method for manufacturing a three-dimensional mold having an uneven pattern shape including at least one of convex portions having different heights and convex portions having inclined surfaces with high resolution. Further, according to the present disclosure, there can be provided a negative resist composition for tone exposure that enables alkali development in pattern formation by irradiation with an electron beam, an ion beam, or EUV, can easily control the height of the convex portion according to the amount of exposure, and can form a three-dimensional pattern with excellent resolution.

Brief Description of the Drawings

[0016]

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BEST MODE FOR CARRYING OUT THE INVENTION

[0017] Hereinafter, embodiments, examples, etc. of the present disclosure will be described with reference to the drawings and the like. However, the present disclosure can be implemented in many different modes, and is not to be construed as being limited to the description of the embodiments and examples exemplified below. Also, the drawings may schematically represent the width, thickness, shape, etc. of each part compared to the actual mode in order to make the description clearer, but this is only an example and does not limit the interpretation of the present disclosure. Also, in this specification and each drawing, the same reference numerals may be given to the same elements as those described above with respect to the already shown drawings, and detailed description may be omitted as appropriate. Also, for convenience of explanation, the terms "above" or "below" may be used in the description, but the up and down directions may be reversed. In this specification, when a certain configuration of a certain member or a certain region, etc. is said to be "above (or below)" another configuration of another member or another region, etc., unless otherwise specified, this includes not only the case where it is directly above (or directly below) the other configuration, but also the case where it is above (or below) the other configuration, that is, the case where another component is included in between above (or below) the other configuration.

[0018] In the present disclosure, the "actinic ray" means far ultraviolet rays such as KrF excimer laser, ArF excimer laser, and F2 excimer laser, electron beam, ion beam, EUV, X-ray, etc. In the notation of the group (atomic group) in the present disclosure, the notation without indicating substitution and non-substitution includes both those having no substituent and those having a substituent. For example, the "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group). The divalent bond of the alkylene group includes not only the case from different carbon atoms (for example, -CH2CH2-), but also a divalent bond from the same carbon atom (for example, -CH2-). Further, the alkyl group and the cycloalkyl group include not only saturated hydrocarbons but also unsaturated hydrocarbons having a double bond, a triple bond, etc. The cycloalkyl group includes not only monocyclic but also polycyclic hydrocarbons such as bicyclic and tricyclic. In the present disclosure, the "phenolic hydroxyl group" means a hydroxyl group directly bonded to an aromatic ring such as benzene. In the present disclosure, the phrase "at least one of X and Y" means "(X), (Y), or (X and Y)". Also, in the present disclosure, "~" indicating a numerical range is used in the sense of including the numerical values described before and after as the lower limit value and the upper limit value. Hereinafter, the method for manufacturing a three-dimensional mold and the negative resist composition for tone exposure of the present disclosure will be described in detail in order.

[0019] I. Method for manufacturing a three-dimensional mold The method for manufacturing a three-dimensional mold according to one embodiment of the present disclosure is a method for manufacturing a three-dimensional mold having an uneven pattern shape including at least one of convex portions having different heights and convex portions having inclined surfaces, a negative resist composition containing a phenolic compound (A) having two or more phenolic hydroxyl groups in one molecule and having two or more substituents selected from the group consisting of hydroxymethyl group and alkoxymethyl group at the ortho position of the phenolic hydroxyl group, with a molecular weight of 400 to 2500, wherein the content of the phenolic compound (A) in the total solid content of the negative resist composition is 70% by weight or more and substantially does not contain an acid generator, and is a non-chemically amplified negative resist composition, is applied on a substrate and then heat-treated to form a resist film, and The step of subjecting the resist film to gradation exposure and development is included.

[0020] In the method for manufacturing a three-dimensional mold according to one embodiment of the present disclosure, a resist film is formed using the negative resist composition which is the specific non-chemically amplified type, and by performing gradation exposure, a three-dimensional mold having an uneven pattern shape including at least one of convex portions having different heights and convex portions having inclined surfaces can be manufactured with high resolution. In the method for manufacturing a three-dimensional mold according to one embodiment of the present disclosure, since the height of the convex portion can be controlled with high precision in proportion to the amount of exposure, a three-dimensional mold having a desired uneven pattern having convex portions with different heights and convex portions having inclined surfaces can be manufactured with high precision. The negative resist composition which is the specific non-chemically amplified type has a relatively gentle slope γ in the sensitivity curve (contrast curve) of the exposure amount and the resist film thickness after development, and it is easy to control the height of the convex portion according to the amount of exposure, and the resist film is difficult to swell during development, and since the molecular weight is relatively small and the molecular weight distribution is narrow, it is presumed that an uneven pattern with high precision and high resolution can be formed.

[0021] Hereinafter, the method for manufacturing such a three-dimensional mold of the present disclosure will be described in detail in order. 1. Three-dimensional mold The three-dimensional mold manufactured by the manufacturing method of the present disclosure has an uneven pattern shape including at least one of convex portions having different heights and convex portions having inclined surfaces. The three-dimensional mold manufactured by the manufacturing method of the present disclosure will be described with reference to the drawings. FIG. 1 is a perspective view schematically showing an example of the three-dimensional mold manufactured by the manufacturing method of the present disclosure, and FIG. 2 is a cross-sectional view schematically showing a part of the E-E' cross-section of FIG. 1. The three-dimensional mold 100 shown in FIG. 1 of the present disclosure includes an uneven pattern layer 10 having an uneven pattern shape 3 in which linear convex portions 1 having inclined surfaces extend in a plurality in a common one direction Y parallel to each other.

[0022] In the present disclosure, the cross-sectional shape of the three-dimensional mold is defined as that obtained by placing the three-dimensional mold at rest on a horizontal plane. In the example of FIG. 1, the X-axis is taken in the repeating direction of the periodic structure, the Y-axis is taken so as to be orthogonal to the X-axis and the XY plane forms the horizontal plane, and the Z-axis is taken in the direction perpendicular to the XY horizontal plane. As shown in FIG. 2, in the present disclosure, the bottom of the valley (the minimum point of Z) between the convex portions is used as a reference with a height of 0, and the portion with a height of 0 is defined as the concave portion 2. Further, in the present disclosure, the portion having a height H (H>0) is defined as the convex portion 1. On the other hand, in the present disclosure, the depth may be defined as the distance from the convex portion to the bottom of the valley between the convex portions with reference to the maximum height of the convex portion. In the present disclosure, the height and the depth are in a front-back relationship. When focusing on the convex portion, it is the height, and when focusing on the concave portion, it is the depth, and they are substantially the same. Therefore, at the bottom of the valley (the minimum point of Z) between the convex portions, when there are a plurality of valleys (the minimum points of Z) having different Z values, it can be said that the convex portions having different heights have concave portions having different depths (for example, see FIG. 10 described later). Also, as shown in FIG. 2, the distance from one end 5 of a certain convex portion to one end 5' on the same side of the adjacent convex portion is defined as the pitch P between the adjacent convex portions 1. The end of the convex portion refers to the portion that starts to have a height H (H>0) from the bottom of the valley (the minimum point of Z) between the convex portions. The pitches between the convex portions may be the same, different from each other, or may have a predetermined repeating period.

[0023] The three-dimensional mold manufactured by the manufacturing method of the present disclosure may further have other configurations in addition to the concavo-convex pattern layer having the concavo-convex pattern shape. For example, the three-dimensional mold manufactured by the manufacturing method of the present disclosure may be one in which a concavo-convex pattern layer is formed on a substrate. Furthermore, as shown in FIG. 3, the three-dimensional mold manufactured by the manufacturing method of the present disclosure may be one in which the concavo-convex pattern layer 10 is formed on the substrate 20 via the adhesion layer 30.

[0024] (1) Concavo-convex pattern shape The concavo-convex pattern shape of the three-dimensional mold manufactured by the manufacturing method of the present disclosure includes at least one of convex portions having different heights and convex portions having inclined surfaces. In the present disclosure, having convex portions with different heights means that one convex portion may have a convex portion (multi-step structure convex portion) whose height changes in several steps, or may have convex portions (multi-value structure convex portions) with different heights from each other, or may have a multi-step structure convex portion in convex portions with different heights from each other. Also, in the present disclosure, a convex portion having an inclined surface can be said to be a form of a convex portion whose height changes in one convex portion.

[0025] Figures 4 and 5 show examples of a convex portion (multi-step structure convex portion) whose height changes in several steps in one convex portion. In the present disclosure, in a cross-sectional shape, a convex portion having two or more flat portions (substantially horizontal portions) may be referred to as a multi-step shape. When the convex and concave portions of the multi-step shape together have n flat portions, it may be referred to as an n-level shape. The example in Figure 4 is a three-level shape, and the example in Figure 5 is a five-level shape. Although not shown, in the case of the cross-sectional shape of a conventional line and space that can be manufactured without performing tone exposure, the flat portion of the convex portion and the flat portion of the concave portion together form a two-level shape. However, the height of the convex portion is constant, it has no inclined surface, and the reference value of the concave portion is constant. Therefore, it does not correspond to the case of having at least one of the convex portions with different heights and the convex portion having an inclined surface in the present disclosure.

[0026] Figure 6 shows an example of a convex portion having an inclined surface. The convex portion in Figure 2 also corresponds to an example of a convex portion having an inclined surface. In the present disclosure, the inclined surface means a surface that is neither perpendicular nor horizontal to the XY horizontal plane and may have a curved surface. In the present disclosure, the inclination angle of the convex portion having an inclined surface may be, for example, 88 degrees or less, 85 degrees or less, 70 degrees or less with respect to the XY horizontal plane, and can also form an angle of 15 degrees or more and 60 degrees or less, 45 degrees or less. Examples of the cross-sectional shape of the convex portion having an inclined surface include a triangular shape as shown in Figure 2, a substantially triangular shape as shown in Figure 6, a quadrangular shape having an inclined surface (not shown), a shape in which a part of a trapezoid is curved, a parabolic shape, a bell shape, a semi-circular shape, a semi-elliptical shape, etc. In the present invention, when the cross-sectional shape of the convex portion having an inclined surface is a triangular shape as shown in FIG. 2 or a substantially triangular shape as shown in FIG. 6, it becomes possible to form an acute angle with respect to the apex angle, which was conventionally impossible. Conventionally, an obtuse angle such as about 120 degrees was formed at the apex angle, whereas a convex portion having an inclined surface with a cross-sectional shape that is a triangular shape or a substantially triangular shape and has an acute angle with the apex angle less than 90 degrees or 80 degrees or less can also be formed.

[0027] Further, FIGS. 7 to 10 show examples including convex portions (multi-valued structure convex portions) having different heights from each other. FIG. 8 shows an example including a multi-stage structure convex portion in convex portions (multi-valued structure convex portions) having different heights from each other. FIG. 9 shows an example including a convex portion having an inclined surface in convex portions (multi-valued structure convex portions) having different heights from each other. The convex portions having different heights from each other may or may not have a predetermined repetition period.

[0028] According to the manufacturing method of the present disclosure, since a three-dimensional mold can be manufactured with high resolution, for example, a three-dimensional mold having a minimum adjacent convex portion interval of 500 nm or less for the convex portions can be manufactured. The minimum adjacent convex portion interval of the convex portions may be appropriately selected according to the purpose of use of the concavo-convex pattern of the three-dimensional mold, and is not particularly limited, but may be 400 nm or less, may be 350 nm or less, or may be 300 nm or less.

[0029] Further, the aspect ratio defined by the height of the convex portion ((height H of the convex portion) / (adjacent convex portion interval P of the convex portion)) with respect to the adjacent convex portion interval P of the convex portion may be appropriately selected according to the purpose of use of the concavo-convex pattern of the three-dimensional mold, and is not particularly limited, but may be 5 or less, and may be 2 or less, from the viewpoint of further etching the three-dimensional mold. On the other hand, from the viewpoint of using the three-dimensional mold as a mold as it is, the aspect ratio may be 0.25 or more. In the present disclosure, as shown in FIG. 10, when the heights are different at the two ends of the convex portion, the height H of the convex portion adopts the maximum height.

[0030] Further, according to the manufacturing method of the present disclosure, since the height of the convex portion can be controlled with high precision in proportion to the amount of exposure, it is easy to realize a desired concavo-convex pattern shape. Conventionally, when performing gradation exposure using a negative resist composition, it has been difficult to form a slope or control the shape of a portion with a relatively small exposure amount. For example, as shown in FIG. 11(A), when forming a pattern with a triangular cross section as an ideal structure, the height of the convex portion is controlled in proportion to the amount of exposure 40. However, in reality, conventionally, as shown in FIG. 11(B), a portion with a small exposure amount adjacent to a portion with a large exposure amount is affected by the portion with a large exposure amount and cannot form a desired slope, and the lower part (rising part) of the convex portion becomes round. As an index indicating that the lower part (rising part) of the convex portion becomes round, as shown in FIG. 11(B), it can be expressed using the radius of curvature R of the arc of the rounded portion at the lower part of the convex portion and the height H of the convex portion. The radius of curvature R of the arc can be obtained by approximating a circle from two coordinates of the arc. The radius of curvature R of the arc can be obtained with reference to JP-A-2004-125690. First, two initial straight lines are applied from near both ends of the point sequence, and then an initial circular arc is applied to the remaining point sequence far from the two initial straight lines. Thereafter, the radius of curvature R of the arc can be obtained by repeating the straight line-circular arc-straight line fitting. According to the manufacturing method of the present disclosure, the radius of curvature of the arc at the lower part of the convex portion can be made 50% or less of the height H of the convex portion. The radius of curvature of the arc at the lower part of the convex portion may be 40% or less, 30% or less, or 25% or less of the height H of the convex portion in order to approach an ideal structure.

[0031] In the present disclosure, the adjacent convex portion interval P, the height H of the convex portion, the width W of the convex portion, the radius of curvature R of the arc, etc. can be measured from an image obtained by photographing a cross section of the three-dimensional mold with an atomic force microscope (AFM) or a scanning electron microscope (SEM). To obtain the minimum adjacent convex portion interval, when the adjacent convex portion interval P is substantially constant, the number of adjacent convex portion intervals P to be obtained may be small. However, when the adjacent convex portion interval P changes periodically, it is preferable to obtain at least five cycles of the adjacent convex portion intervals P. When the adjacent convex portion interval P changes non-periodically, it is preferable to obtain more adjacent convex portion intervals P.

[0032] The concavo-convex pattern shape of the three-dimensional mold manufactured by the manufacturing method of the present disclosure is not particularly limited as long as it has convex portions with different heights and convex portions having inclined surfaces formed by using tone exposure, and can be implemented in many different modes. The concavo-convex pattern shape of the three-dimensional mold manufactured by the manufacturing method of the present disclosure may not have a periodic structure, or even if it has a periodic structure, it may have a plurality of regions having different periodic structures. For example, the regions of the plurality of sub-periodic structures include those having convex portions with different shapes, heights, and adjacent convex portion intervals of the convex portions.

[0033] (2) Concavo-convex pattern layer The concavo-convex pattern layer 10 having the concavo-convex pattern shape 3 is made of a cured product of the specific negative resist composition. Since the specific negative resist composition will be described in detail later, the description here will be omitted. The concavo-convex pattern layer having a concavo-convex pattern shape may not be connected at the lower part of the convex portion. That is, the concavo-convex pattern layer may be composed of a group of convex portions without the cured product of the specific negative resist composition existing in the concave portion of the concavo-convex pattern.

[0034] The thickness of the concavo-convex pattern layer 10 may be appropriately adjusted according to the concavo-convex pattern shape according to the use of the three-dimensional mold, and is not particularly limited. The thickness of the concavo-convex pattern layer 10 may be, for example, 50 nm to 500 nm, and may further be 500 nm to 2000 nm.

[0035] (3) Substrate As the substrate used for the three-dimensional mold manufactured by the manufacturing method of the present disclosure, there are no particular restrictions, such as quartz, glass, optical film, ceramic material, vapor deposition film, magnetic film, reflective film, metal substrates such as Ni, Cu, Cr, Fe, paper, SOG (Spin On Glass), polymer substrates such as polyester film, polycarbonate film, polyimide film, TFT array substrate, electrode plate of PDP, glass or transparent plastic substrate, conductive substrates such as ITO and metal, insulating substrates, semiconductor manufacturing substrates such as silicone, silicon nitride, polysilicon, silicon oxide, amorphous silicon, etc. As the photomask substrate, a substrate having a light-shielding layer or a low-reflection layer such as CrxOyNz, MoSi, MoSiO, MoSiON, TaSiO, TaBO, TaBN, etc. on a transparent quartz glass substrate is preferably used. The thickness of the substrate may be appropriately selected according to the application and is not particularly limited. The thickness of the substrate 20 may be, for example, 0.1 mm to 1 mm, and further may be 1 mm to 10 mm.

[0036] (4) Adhesion layer On the substrate used for the three-dimensional mold manufactured by the manufacturing method of the present disclosure, in order to improve the adhesion between the specific negative resist composition or its cured product and the substrate, an adhesion layer may be provided on the substrate with surface treatment using an adhesive or the like. Examples of the adhesive used for the adhesion layer include hexamethyldisilazane, silane coupling agents, acid anhydrides, phosphate esters, etc. In particular, those having a functional group capable of reacting with the ethylenically unsaturated bond of the resin composition are preferred. For example, vinyltrimethoxysilane (trade name KBM-1003, Shin-Etsu Chemical Co., Ltd.), 3-acryloxypropyltrimethoxysilane (trade name KBM-5103, Shin-Etsu Chemical Co., Ltd.), p-styryltrimethoxysilane (trade name KBM-1403, Shin-Etsu Chemical Co., Ltd.), ACR YLOXYMETHYLTRIMETHOXYSILANE (trade name SIA0182.0, Gelest), β-carboxyethyl acrylate (trade name β-CEA, UCB Chemical) disclosed in JP-A-2009-503139, trade name Ebecryl3605 (UCB Chemical), trade name Isorad501 (Schenectady International, inc), Composition 1 to 5, etc. are mentioned. The thickness of the adhesion layer 30 may be appropriately selected according to the application and is not particularly limited. For example, it may be 10 nm to 100 nm, or may be 100 nm to 2000 nm. In addition, the three-dimensional mold manufactured by the manufacturing method of the present disclosure may further have other configurations.

[0037] 2. Step of forming a resist film In the method for manufacturing a three-dimensional mold of the present disclosure, a negative resist composition containing a phenolic compound (A) having two or more phenolic hydroxyl groups in one molecule and two or more substituents selected from the group consisting of hydroxymethyl groups and alkoxymethyl groups at the ortho position of the phenolic hydroxyl group, with a molecular weight of 400 to 2500, and having a content of the phenolic compound (A) of 70% by weight or more in the total solid content of the negative resist composition and substantially not containing an acid generator, is applied onto a substrate and then heat-treated to form a resist film.

[0038] (1) Negative resist composition The specific phenolic compound (A) is a relatively low-molecular-weight specific phenolic compound serving as a resist substrate, and as a crosslinkable group, one or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group are introduced at the ortho position of the phenolic hydroxyl group. That is, the specific phenolic compound (A) is a resist substrate that also functions as a crosslinking agent. The specific phenolic compound (A) has a high ratio of crosslinkable groups to hydroxyl groups and a high content in the total solid content of the phenolic compound (A) in the resist composition. Therefore, in the negative resist composition which is a non-chemically amplified type of the present disclosure, by irradiating active energy rays, the crosslinking reaction of the crosslinkable groups of the specific phenolic compound (A) proceeds without going through an acid. Since the above negative resist composition has a phenolic hydroxyl group, it is alkali-soluble. However, during resist pattern formation, upon exposure (irradiation with light) such as an electron beam, crosslinking bonds are formed between the above phenolic compounds (A) due to the presence of one or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group present at the ortho position of the phenolic hydroxyl group, resulting in alkali-insolubility. Therefore, in resist pattern formation, when a resist film made of the negative resist composition is selectively exposed, the exposed portion becomes alkali-insoluble while the unexposed portion remains alkali-soluble and does not change, so a negative resist pattern can be formed by alkali development. In addition, since the non-chemically amplified negative resist composition of the present disclosure uses the relatively low-molecular-weight specific phenolic compound (A) in a state where the solid content of the resist composition is high, the uniformity of the resist composition in the coating film is improved. Furthermore, since it does not utilize acid diffusion during image formation, it is estimated to be excellent in resolution while being able to easily control the height of the convex portion according to the amount of exposure and having excellent tone exposure performance.

[0039] Hereinafter, each component of such a negative resist composition of the present disclosure will be described in detail in order. <Phenolic Compound (A)> The phenolic compound (A) used in the present disclosure has two or more phenolic hydroxyl groups in one molecule, and has two or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group at the ortho position of the phenolic hydroxyl group in one molecule, and is a compound having a molecular weight of 400 to 2500. By setting the molecular weight of the phenolic compound (A) within the above range, excellent resolution can be obtained.

[0040] The phenolic compound (A) used in the present disclosure only needs to have two or more phenolic hydroxyl groups in one molecule, and the number of phenolic hydroxyl groups in one molecule is not particularly limited. The phenolic compound (A) used in the present disclosure is preferably appropriately selected so as to have alkali solubility based on the following. It is preferable to select and use the phenolic compound (A) having a development rate of 0.5 nm / sec or more with respect to an aqueous solution of tetramethylammonium hydroxide (TMAH) having a concentration of 25% by mass (23 °C), and more preferably to select and use the one having a development rate of 1.0 nm / sec or more. By setting the alkali development rate of the alkali-soluble resin within the above range, the pattern shape can be improved.

[0041] For example, the development rate with respect to an aqueous solution of tetramethylammonium hydroxide (TMAH) having a concentration of 25% by mass (23 °C) can be measured and calculated by, for example, using the above phenolic compound (A) alone, forming a coating film on a silicon wafer so that the film thickness after drying becomes 300 nm as a 5% by mass solution, immersing it in an aqueous solution of tetramethylammonium hydroxide (TMAH) having a concentration of 25% by mass (23 °C), and measuring the time until the coating film is completely dissolved.

[0042] The phenolic compound (A) used in the present disclosure may have two or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group at the ortho position of the phenolic hydroxyl group in one molecule. One or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group at the ortho position of the phenolic hydroxyl group function as a crosslinkable group of the phenolic compound. It is preferable that the phenolic compound (A) used in the present disclosure has three or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group in one molecule, and more preferably four or more in one molecule, from the viewpoint of enhancing crosslinkability.

[0043] As the alkoxymethyl group, those having 1 to 6 carbon atoms in the alkoxy group are preferable. Specifically, methoxymethyl group, ethoxymethyl group, n-propoxymethyl group, isopropoxymethyl group, n-butoxymethyl group, sec-butoxymethyl group, t-butoxymethyl group, various pentyloxymethyl groups, etc. can be mentioned. Among them, as the alkoxymethyl group, methoxymethyl group and ethoxymethyl group are preferable from the viewpoint of good sensitivity.

[0044] Among others, as the crosslinkable group, one or more substituents selected from the group consisting of a hydroxymethyl group, a methoxymethyl group, and an ethoxymethyl group at the ortho position of the phenolic hydroxyl group are preferable from the viewpoint of high reactivity and good sensitivity.

[0045] As the phenolic compound (A) used in the present disclosure, a compound having a molecular weight of 400 to 2500 is selected and used. If the molecular weight is less than the lower limit value, the ability to form a resist film and the ability to form a pattern may be inferior. On the other hand, if the molecular weight exceeds the upper limit value, it is likely to swell by the solvent used in the resist composition, pattern collapse is likely to occur, and the shape of the pattern may deteriorate. The molecular weight here refers to the sum of the atomic weights of the atoms constituting the molecule. In the case of an oligomer having a molecular weight distribution, it is represented by the mass average molecular weight using GPC (polystyrene conversion). Among others, the molecular weight of the phenolic compound (A) used in the present disclosure is preferably from 500 to 2500, more preferably from 600 to 2000 from the viewpoints of film-forming property and resolution.

[0046] The phenolic compound (A) used in the present disclosure preferably has a glass transition temperature (Tg) of 60°C or higher, more preferably 90°C or higher. When the glass transition temperature is 60°C or higher, dewetting is less likely to occur during film formation, and a uniform film is easily obtained. Note that the dewetting phenomenon refers to a phenomenon in which a spread coating film melts during pre-baking, repelling occurs, and a uniform film is not formed. Generally, when a low-boiling solvent is used as the solvent for the resist composition, the resist film dries rapidly and a uniform film cannot be obtained. Therefore, in order to obtain a uniform resist film when applying by spin coating or the like, a solvent having a boiling point of 90 to 180°C is used. Since the resist film formed by the spin coating method contains a large amount of residual solvent, in order to remove this solvent and form a stable resist film, the resist substrate is heated on a hot plate at a temperature of 90°C or higher (pre-baking). However, when a phenolic compound having a glass transition temperature of less than 60°C is used, dewetting of the resist film may occur in the pre-baking process, and a uniform film may not be obtained. On the other hand, when a phenolic compound having a glass transition temperature of 60°C or higher is used, pre-baking at a high temperature becomes possible, and a uniform film can be obtained. In addition, a resist film excellent in environmental resistance (post-coating delay: PCD) can be obtained. Furthermore, it is possible to suppress the density dependence of the pattern generated during pattern formation by electron beam. Also, in the dry etching process after resist pattern formation, a pattern excellent in etching resistance (capable of preventing melting of the pattern due to high temperature during etching) can be obtained. Note that the glass transition temperature here is measured by a differential scanning calorimeter (DSC).

[0047] In addition, the phenolic compound (A) used in the present disclosure preferably has a solubility of 5% by mass or more at 23°C in an organic solvent having a boiling point of 80 to 180°C. In such a case, it is possible to prevent rapid drying of the resist film during spin coating, and there is an advantage that a uniform resist film can be obtained. Representative examples of the organic solvent having a boiling point of 80 to 180°C include cyclopentanone, propylene glycol monomethyl ether, cyclohexanone, propylene glycol monomethyl ether acetate, ethyl lactate, 2-heptanone, diethylene glycol dimethyl ether, 1-ethoxy-2-propanol, and the like.

[0048] Among them, the phenolic compound (A) used in the present disclosure preferably has a glass transition temperature (Tg) of 60°C or higher and a solubility of 5% by mass or more at 23°C in an organic solvent having a boiling point of 80 to 180°C.

[0049] The phenolic compound (A) is not particularly limited and can be appropriately selected and used. For example, compounds represented by the following chemical formula (1) and chemical formula (3) can be mentioned.

[0050]

Chemical formula

[0051]

Chemical formula

[0052]

Chemical Structure

[0053] In the compound represented by the above chemical formula (1), the alkyl group of R 1 is not particularly limited, but an alkyl group having 1 to 18 carbon atoms is preferred. The alkyl group may be linear or branched. For example, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an i-propyl group, an i-butyl group, a t-butyl group, an i-pentyl group, a t-pentyl group, a hexadecyl group, etc. may be mentioned. Also, it may have an unsaturated bond such as a double bond or a triple bond.

[0054] Examples of the substituent of the alkyl group include a hydroxyl group, an alkoxy group, a halogen atom, a halogenoalkyl group, etc.

[0055] R 1 The cycloalkyl group of R is not particularly limited, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, etc. Further, it may have an unsaturated bond such as a double bond or a triple bond, and may be either monocyclic or polycyclic. As the cycloalkyl group, a cyclohexyl group is preferable.

[0056] The substituent of the cycloalkyl group is not particularly limited, and examples thereof include an alkyl group having 1 to 5 carbon atoms, a hydroxyl group, an alkoxy group, an alkoxyalkyl group, a halogen atom, a halogenoalkyl group, etc.

[0057] The alkyl group having 1 to 5 carbon atoms may be either linear or branched. Examples of the linear alkyl group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, etc. Examples of the branched alkyl group include an i-propyl group, an i-butyl group, a t-butyl group, an i-pentyl group, a t-pentyl group, etc.

[0058] Also, the alkoxy group is not particularly limited, but an alkoxy group having 1 to 8 carbon atoms is preferable, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a 2-ethylhexyloxy group, etc.

[0059] The alkoxyalkyl group is not particularly limited, but an alkoxyalkyl group having 1 to 8 carbon atoms is preferable, and examples thereof include a methoxymethyl group, an ethoxymethyl group, a methoxyethyl group, an ethoxyethyl group, a methoxypropyl group, etc.

[0060] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0061] The halogenoalkyl group is not particularly limited, but a halogenoalkyl group having 1 to 8 carbon atoms is preferred. Examples thereof include a chloromethyl group, a dichloromethyl group, a trichloromethyl group, a bromomethyl group, a dibromomethyl group, a tribromomethyl group, a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a 1-chloroethyl group, a 1-bromoethyl group, a 1-fluoroethyl group, a 1,2-dichloroethyl group, a 1,1,2,2-tetrachloroethyl group, and the like.

[0062] R 1 The aryl group of R is not particularly limited, but preferably has 6 to 14 carbon atoms, more preferably 6 to 10 carbon atoms. Examples thereof include a phenyl group, a naphthyl group, an anthryl group, and the like.

[0063] Examples of the substituent of the aryl group include a hydroxymethyl group, an alkoxymethyl group, a cycloalkyl group, an alkyl group having 1 to 5 carbon atoms, a hydroxyl group, an alkoxy group, an alkoxyalkyl group, a halogen atom, a halogenoalkyl group, and the like. Examples of the cycloalkyl group as the substituent of the aryl group are the same as those of the above cycloalkyl group. The cycloalkyl group may have a substituent, and examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a halogen atom, a cyano group, a hydroxyl group, an alkoxy group, and the like. Examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, an i-propyl group, and the like. The alkoxy group is not particularly limited, but an alkoxy group having 1 to 8 carbon atoms is preferred, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a 2-ethylhexyloxy group, and the like. The alkyl group having 1 to 5 carbon atoms, the alkoxy group, the alkoxyalkyl group, the halogen atom, the halogenoalkyl group, and the alkoxymethyl group as the substituent of the aryl group are as described above.

[0064] In the above chemical formula (2), R 4 and R 5is, independently of each other, a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. The alkyl group having 1 to 3 carbon atoms may be either linear or branched, and among them, a methyl group and an ethyl group are preferable from the viewpoint of etching resistance. When m is 2, the two R 4 and R 5 may be the same or different from each other. In the above chemical formula (2), when both R 4 and R 5 are hydrogen atoms, it is preferably used.

[0065] Examples of the aryl group of Q in the above chemical formula (2) include the same ones as the above aryl group. The substituents of the aryl group of Q include the same ones as the substituents of the above aryl group, and may include one or more substituents selected from the group consisting of a hydroxyl group, a hydroxymethyl group, and an alkoxymethyl group. Further, examples of the cycloalkyl group of Q in the above chemical formula (2) include the same ones as the above cycloalkyl group. The substituents of the cycloalkyl group of Q include the same ones as the substituents of the above cycloalkyl group.

[0066] The monovalent organic group of R 2 is not particularly limited, and examples thereof include an alkyl group, a cycloalkyl group, and an aryl group. Examples of the alkyl group of R 2 include the same ones as the above R 1 . Examples of the substituents of the alkyl group of R 2 include the same ones as those of the above R 1 . Further, the cycloalkyl group of R 2 and the substituents of the cycloalkyl group can be the same as those of the above R 1 . Furthermore, the aryl group of R 2 and the substituents of the aryl group can be the same as those of the above R 1 .

[0067] R 3The alkoxymethyl group is as described above. R 3 As the halogen atom and alkyl group of 3 , those similar to the above R 1 can be mentioned. R 3 The substituents of the alkyl group as R 3 include cycloalkyl group, aryl group, amino group, amide group, ureido group, urethane group, hydroxyl group, carboxy group, halogen atom, alkoxy group, thioether group, acyl group, acyloxy group, alkoxycarbonyl group, cyano group, nitro group, etc.

[0068] R 3 The cycloalkyl group of R 3 and the substituents of the cycloalkyl group can be the same as those of the above R 1 . The aryl group of R 3 and the substituents of the aryl group can be the same as those of the above R 1 . 1 R 3 R 1 can be the same as those of the above. Also, as the alkoxy group of R 3 , those similar to the above R 1 can be mentioned. 3 R 1

[0069] R 3 The acyl group of R 3 is not particularly limited, but an acyl group having 1 to 8 carbon atoms is preferable, and examples thereof include formyl group, acetyl group, propionyl group, butyryl group, valeryl group, pivaloyl group, benzoyl group, etc.

[0070] x1 is an integer of 3 to 12, preferably an integer of 4 to 12, more preferably an integer of 4 to 8.

[0071] The compound represented by the above chemical formula (1) has two or more phenolic hydroxyl groups in one molecule, and if it has one or more substituents selected from the group consisting of hydroxymethyl group and alkoxymethyl group at the ortho position of the phenolic hydroxyl group, the substituents indicated by the same symbol in each repeating unit may be the same or different. The positions of OR 2 and R 3 in each repeating unit may be the same or different.

[0072] In the compound represented by the above chemical formula (1), from the viewpoint of obtaining a pattern with high sensitivity, high resolution, and good shape, among others, it is preferable that x1 is 4 and n1 is 2. Further, among the eight Rs where x1 is 4 and n1 is 2 2 is a calixresorcinarene derivative having 4 to 8 hydrogen atoms among the eight Rs, and further, it is preferable that one or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group are present at one or more positions in the ortho position where R 2 is a hydrogen atom in one molecule. Also, in the compound represented by the above chemical formula (1), from the viewpoint of obtaining a pattern with high sensitivity, high resolution, and good shape, among others, it is preferable that x1 is 4 and n1 is 2. Further, among the eight Rs where x1 is 4 and n1 is 2 2 is a calixresorcinarene derivative having 0 to 8 hydrogen atoms among the eight Rs, and further, it is preferable that R 1 has an aryl group containing a phenolic hydroxyl group and one or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group at the ortho position of the phenolic hydroxyl group.

[0073] On the other hand, in the compound represented by the above chemical formula (3), the alkyl groups in R 6 , R 7 , R 8 and R 9 may be linear or branched, and preferably include those having 1 to 10 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, an isobutyl group, a hexyl group, an octyl group, etc. R 6 , R 7 , R 8 and R 9The cycloalkyl group in may be either monocyclic or polycyclic. For example, it may be a group having a monocyclo, bicyclo, tricyclo, or tetracyclo structure having 5 or more carbon atoms. It preferably has 6 to 30 carbon atoms, and more preferably has 7 to 25 carbon atoms, and examples thereof include an adamantyl group, a noradamantyl group, a decalin residue, a tricyclodecanyl group, a tetracyclododecanyl group, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecanyl group, and a cyclododecanyl group. These alicyclic hydrocarbon groups may have a substituent. R 6 , R 7 , R 8 and R 9 The aryl group in R 1 It may be the same as: Also, R 6 , R 7 , R 8 and R 9 The hydroxymethyl group or alkoxymethyl group in may be the same as above. In the compound represented by the above chemical formula (3), R 6 If (x2) is an integer greater than or equal to 2, the group is (x2)-valent.

[0074] Examples of the substituent that the above-mentioned alkyl group, cycloalkyl group, and aryl group may have include a hydroxyl group, a carboxyl group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an alkoxy group (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, etc.), a hydroxymethyl group, or an alkoxymethyl group.

[0075] R 10 and R 11The monovalent organic group in [reference] refers to an alkyl group, an aryl group, an aralkyl group, an alkoxy group, an alkoxycarbonyl group, an amide group, a cyano group, etc. The alkyl group is preferably an alkyl group or a cycloalkyl group having 1 to 10 carbon atoms. For example, a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a hexyl group, a 2-ethylhexyl group, an octyl group, a cyclopropyl group, a cyclobutyl group, a cyclohexyl group, an adamantyl group, etc. can be mentioned. The aryl group is preferably an aryl group having 6 to 14 carbon atoms. For example, a phenyl group, a naphthyl group, an anthracenyl group, etc. can be mentioned. The aralkyl group is preferably an aralkyl group having 6 to 12 carbon atoms. For example, a benzyl group, a phenethyl group, a cumyl group, etc. can be mentioned. The alkoxy group in the alkoxy group and the alkoxycarbonyl group is preferably an alkoxy group having 1 to 5 carbon atoms. For example, a methoxy group, an ethoxy group, a propoxy group, an n-butoxy group, an isobutoxy group, etc. can be mentioned.

[0076] The alkylene group in W may be linear or branched, and preferably has 1 to 10 carbon atoms. For example, a methylene group, an ethylene group, a propylene group, a butylene group, an isobutylene group, etc. can be mentioned. The cycloalkylene group in W may be monocyclic or polycyclic. Examples of the alkylene group forming the ring include cycloalkylene groups having 3 to 8 carbon atoms (for example, a cyclopentylene group, a cyclohexylene group). The alkylene group and the cycloalkylene group in W may further have a substituent. Examples of the substituent include an alkyl group (preferably having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, etc.), an alkoxy group (preferably having 1 to 4 carbon atoms, such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, etc.), a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.

[0077] Further, the alkylene chain or cycloalkylene chain may contain -O-, -OC(=O)-, -OC(=O)O-, -N(R)-C(=O)-, -N(R)-C(=O)O-, -S-, -SO-, -SO2- in the alkylene chain. Here, R is a hydrogen atom or an alkyl group (preferably having 1 to 10 carbon atoms, such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, etc.). Preferred examples of the cyclic arylene group in W include those having 6 to 15 carbon atoms such as phenylene group, tolylene group, naphthylene group, etc.

[0078] Specific examples of the phenolic compound (A) are shown below, but the present disclosure is not limited thereto. If there are two or more phenolic hydroxyl groups in one molecule and two or more substituents selected from the group consisting of hydroxymethyl group and alkoxymethyl group are present at the ortho position of the phenolic hydroxyl group in one molecule, the phenolic hydroxyl groups in the following specific examples may be protected with an organic group. In addition, in the following formula, L is each independently a hydrogen atom or one or more substituents selected from the group consisting of hydroxymethyl group and alkoxymethyl group, and at least two Ls in one molecule are one or more substituents selected from the group consisting of hydroxymethyl group and alkoxymethyl group present at the ortho position of the phenolic hydroxyl group. Also, the molecular weight should satisfy 400 to 2500.

[0079]

Chemical formula

[0080]

Chemical formula

[0081]

Chemical formula

[0082] [Chem.]

[0083] [Chem.]

[0084] The phenolic compound (A) used in the present disclosure can be obtained by introducing at least one substituent selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group at the ortho position of the phenolic hydroxyl group in the parent compound of the phenolic compound. As a method for introducing a substituent that functions as the above crosslinkable group into the parent compound of the phenolic compound, for example, it can be obtained by reacting a phenolic compound having no corresponding hydroxymethyl group with formaldehyde under a base catalyst. At this time, in order to prevent side reactions such as gelation, it is preferable to carry out the reaction at a reaction temperature of 50°C or lower. Also, various bisphenol derivatives having an alkoxymethyl group can be obtained by reacting a bisphenol derivative having a corresponding hydroxymethyl group with an alcohol under an acid catalyst. At this time, in order to prevent side reactions such as gelation, it is preferable to carry out the reaction at a reaction temperature of 100°C or lower.

[0085] The parent compound of the phenolic compound (A) is commercially available from, for example, Honshu Chemical Industry Co., Ltd., Asahi Organic Materials Industry Co., Ltd., etc., and these can be used. It can also be synthesized by condensation of various phenolic compounds with various aldehydes and ketones.

[0086] In the negative resist composition according to the present disclosure, the phenolic compound (A) may be used alone or in combination of two or more of the above-described compounds. However, in the negative resist composition according to the present disclosure, it is preferable that the purity of the phenolic compound (A) with the same structural formula is 70% by mass or more from the viewpoint of forming a good pattern. The phenolic compound (A) more preferably has a purity of 80% by mass or more of the compound with the same structural formula, and even more preferably 90% by mass or more. When a phenolic compound (A) having a high purity of a compound with the same structural formula is used, it is presumed that the progress of development becomes uniform. However, even if the purity of the compound with the same structural formula of the phenolic compound (A) is less than the above value, it can be preferably used when the structure of the impurity is similar to that of the phenolic compound (A) and the compatibility is good.

[0087] As the phenolic compound used in the present disclosure, it is preferable that it does not have a molecular weight distribution. Even if the phenolic compound used in the present disclosure has a molecular weight distribution, those having a small molecular weight distribution are preferable, and the molecular weight distribution (mass average molecular weight <mw>and number average molecular weight Ratio <mw> / It is preferably 1.0 to 1.1.

[0088] The content of the phenolic compound (A) is 70% by mass or more, preferably 80% by mass or more, and more preferably 90% by mass or more, based on the total solid content of the resist composition. The content of the phenolic compound (A) may be 95% by mass or more, 98% by mass or more, 99% by mass or more, or 100% by mass, based on the total solid content of the resist composition. On the other hand, when the resist composition contains the organic basic compound (B) described below, the content of the phenolic compound (A) may be 99.9% by mass or less, or 99.1% by mass or less, based on the total solid content of the resist composition. In the present disclosure, the solid content means the components other than the organic solvent among the components contained in the negative resist composition.

[0089] <Organic basic compound (B)> The negative resist composition which is a non-chemically amplified type used in the present disclosure preferably further contains an organic basic compound (B) because it becomes easier to control the height of the convex portion with high precision in proportion to the amount of exposure, and the tone exposure performance is improved. When the negative resist composition which is a non-chemically amplified type used in the present disclosure further contains an organic basic compound (B), unlike the organic basic compound of the chemically amplified resist composition used as a quencher of the acid generator, it can be controlled so that the condensation reaction between the specific phenolic compounds (A) hardly occurs, and it becomes easier to control the height of the convex portion with high precision in proportion to the amount of exposure, and it is estimated that the tone exposure performance is improved.

[0090] The organic basic compound (B) can be arbitrarily selected from known organic basic compounds and used.

[0091] Examples of the organic basic compound (B) include nitrogen-containing organic compounds, such as nitrogen-containing compounds having a nitrogen atom, amide group-containing compounds, urea compounds, and nitrogen-containing heterocyclic compounds, but are not limited thereto. Compounds containing a polar group such as an ether bond, a carbonyl bond, an ester bond, a carbonate bond, a sulfide bond, or a sulfone bond in the chain, or compounds containing a polar group such as an ester group, an acetal group, a cyano group, an alkoxy group, or a hydroxyl group as a substituent in these nitrogen-containing organic compounds are also preferably used.

[0092] Examples of nitrogen-containing organic compounds include mono(cyclo)alkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-dodecylamine, cyclohexylamine; di(cyclo)alkylamines such as di-n-butylamine, di-n-pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine, methyl-n-dodecylamine, di-n-dodecylmethylamine, cyclohexylmethylamine, dicyclohexylamine; tri(cyclo)alkylamines such as triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, dimethyl-n-dodecylamine, di-n-dodecylmethylamine, dicyclohexylmethylamine, tricyclohexylamine; alkanolamines such as monoethanolamine, diethanolamine, triethanolamine; aromatic amines such as aniline, N-methylaniline, N,N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine, tribenzylamine, 1-naphthylamine;Ethylenediamine, N,N,N’,N’-tetramethylethylenediamine, N,N,N’,N’-tetrakis(2-hydroxypropyl)ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4’-diaminodiphenylmethane, 4,4’-diaminodiphenylether, 4,4’-diaminobenzophenone, 4,4’-diaminodiphenylamine, 2,2-bis(4-aminophenyl)propane, 2-(3-aminophenyl)-2-(4-aminophenyl)propane, 2-(4-aminophenyl)-2-(3-hydroxyphenyl)propane, 2-(4-aminophenyl)-2-(4-hydroxyphenyl)propane, 1,4-bis[1-(4-aminophenyl)-1-methylethyl]benzene, 1,3-bis[1-(4-aminophenyl)-1-methylethyl]benzene, polyethyleneimine, 2,2-(phenylimino)diethanol, polyallylamine, polymer of N-(2-dimethylaminoethyl)acrylamide, tris(2-acetoxyethyl)amine, tris(2-pivaloyloxyethyl)amine, tris(2-t-butoxycarbonyloxyethyl)amine, tris[2-(2-oxopropoxy)ethyl]amine, tris[2-(methoxycarbonylmethyl)oxyethyl]amine, tris[2-(t-butoxycarbonylmethyloxy)ethyl]amine, tris[2-(2-methoxyethoxy)ethyl]amine, N-[2-(methylsulfonyl)ethyl]diethanolamine, N-[2-(methylsulfonyl)ethyl]bis(2-acetoxyethyl)amine, N-[2-(methylsulfonyl)ethyl]bis(2-formyloxyethyl)amine, N-[2-(methylsulfonyl)ethyl]bis(2-methoxyethyl)amine, dimethyl 3,3’-[2-(methylsulfonyl)ethyl]iminodipropionate, N-(tetrahydrofurfuryl)bis[2-(methylsulfonyl)ethyl]amine, t-butyl 3-[bis(2-methoxyethyl)amino]propionate, t-butyl 3-[bis(2-acetoxyethyl)amino]propionate, etc. are mentioned.;

[0093] Examples of the amide group-containing compound include formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, and the like.

[0094] Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n-butylthiourea, and the like.

[0095] Examples of the nitrogen-containing heterocyclic compounds include imidazoles such as imidazole, benzimidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole, 2-phenylbenzimidazole, 4,5-diphenylimidazole, 2,4,5-triphenylimidazole; pyridines such as pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 8-hydroxyquinoline, acridine; and pyrazine, pyrazole, pyridazine, quinazoline, purine, pyrrolidine, piperidine, morpholine, 4-methylmorpholine, piperazine, 1,4-dimethylpiperazine, 1,4-diazabicyclo[2.2.2]octane, 1-[2-(methoxymethoxy)ethyl]pyrrolidine, 1-[2-(2-methoxyethoxy)methoxy]ethyl]pyrrolidine, 1-[2-(2-methoxyethoxy)methoxy]ethyl]piperidine, 3-hydroxy-piperidine, 4-hydroxy-piperidine, 4-[2-(methoxymethoxy)ethyl]morpholine, 4-[2-(2-methoxyethoxy)methoxy]ethyl]morpholine 1-(2’,3’-dihydroxylpropyl)-2-methylimidazole, 1,3-di(2’-methyl-1’-imidazolylmethyl)benzene, 1-benzyl-2-methylimidazole, 1-benzylimidazole, 2-(1H-benzimidazol-1-yl)ethyl acetate, 2-(2-phenyl-1H-benzimidazol-1-yl)ethyl acetate, methyl 3-(2-phenyl-1H-benzimidazol-1-yl)propionate, 1-[2-(1,3-dioxolan-2-yl)ethyl]1H-benzimidazole, 4-(1H-benzimidazol-1-yl)butyronitrile, t-butyl 3-morpholinopropionate, t-butyl 3-piperidinopropionate, 1-ethylcyclopentyl 3-piperidinopropionate, 1-ethyl-2-norbornyl 3-piperidinopropionate, and the like.

[0096] The organic basic compound (B) may be an organic basic compound containing a hydroxyl group from the viewpoint of improving the compatibility with the phenolic compound (A). The organic basic compound containing a hydroxyl group may be at least one of an amine compound containing a hydroxyl group and a nitrogen-containing heterocyclic compound containing a hydroxyl group.

[0097] Further, the organic basic compound (B) may be a secondary amine compound. For example, piperidine corresponds to both a nitrogen-containing heterocyclic compound and a cyclic secondary amine compound.

[0098] Further, the organic basic compound (B) may be a secondary amine compound having a hydroxyl group. Examples of the secondary amine compound having a hydroxyl group include 3-hydroxy-piperidine, 4-hydroxy-piperidine, diethanolamine, and the like.

[0099] These organic basic compounds (B) can be used alone or in combination of two or more. The content of the organic basic compound (B) may be appropriately selected according to the improvement of the gradation exposure performance. For example, it is preferably 0.01 part by mass to 10 parts by mass, more preferably 0.1 part by mass to 5 parts by mass, based on 100 parts by mass of the phenolic compound (A). If it is less than 0.01 part by mass, the effect of the addition may not be obtained. The content of the organic basic compound (B) may be 0.01% by mass or more, may be 0.09% by mass or more, may be 10% by mass or less, may be 9.1% by mass or less, and may be 5% by mass or less based on the total solid content of the resist composition.

[0100] <Other Components> Since the non-chemically amplified negative resist composition of the present disclosure is non-chemically amplified, it does not substantially contain an acid generator. Here, not substantially containing means not containing to the extent that it substantially functions as a chemically amplified type. In the case of a non-chemically amplified resist composition, the content of the photoacid generator is less than 1 part by mass with respect to 100 parts by mass of the phenolic compound (A), may be 0 part by mass, and is preferably less than 2% by mass with respect to the total solid content of the resist composition, and may be 0% by mass.

[0101] Since the non-chemically amplified negative resist composition of the present disclosure uses the above-mentioned specific phenolic compound (A), it is not necessary to contain a phenolic compound having no hydroxymethyl group or alkoxymethyl group. Phenolic compounds that do not correspond to the above-mentioned phenolic compound (A) of the present application, such as phenolic compounds having no hydroxymethyl group or alkoxymethyl group, may be contained as long as the effects of the present disclosure are not impaired, but it is preferably not contained from the viewpoint of low line edge roughness.

[0102] In addition, since the non-chemically amplified negative resist composition of the present disclosure uses the above-mentioned specific phenolic compound (A), it is not necessary to separately contain a conventionally used crosslinking agent. However, a small amount of the crosslinking agent may be added within the range where the effects of the present disclosure are not impaired to improve the resist sensitivity. The content of such a crosslinking agent can be based on 10% by mass or less, more preferably 5% by mass or less, with respect to the total solid content of the resist composition.

[0103] The crosslinking agent that does not correspond to the specific phenolic compound (A) is not particularly limited, and it can be arbitrarily selected from known crosslinking agents used in conventional chemically amplified negative resist compositions. For example, 4,4'-methylenebis[2,6-bis(hydroxymethyl)]phenol (MBHP), 4,4'-methylenebis[2,6-bis(methoxymethyl)]phenol (MBMP), 2,3-dihydroxy-5-hydroxymethylnorbornane, 2-hydroxy-5,6-bis(hydroxymethyl)norbornane, cyclohexanedimethanol, 3,4,8(or 9)-trihydroxytricyclodecane, 2-methyl-2-adamantanol, 1,4-dioxane-2,3-diol, 1,3,5-trihydroxycyclohexane, and other aliphatic cyclic hydrocarbons having a hydroxyl group or a hydroxyalkyl group or both, or oxygen-containing derivatives thereof can be mentioned. Also, a melamine-based crosslinking agent, a urea-based crosslinking agent, an alkylene urea-based crosslinking agent, or a glycoluril-based crosslinking agent using glycoluril may be used.

[0104] In addition, in the non-chemically amplified negative resist composition of the present disclosure, an oligomer or polymer component for improving the performance of the resist film may be added within a range not impairing the effects of the present disclosure. By adding an oligomer or polymer component and introducing a network structure into the resist film, it may be possible to improve the resolution by improving the pattern strength and improve the pattern shape (line edge roughness). The content of such an oligomer or polymer component is preferably 5% by mass or less, more preferably 3% by mass or less, based on the total solid content of the resist composition. Examples of the oligomer or polymer component include novolak resins, polyhydroxystyrene derivatives, and acrylic copolymers derived from acrylic acid and methacrylic acid, which are alkali-developable resins conventionally used in negative resist compositions for i-line, KrF, and ArF. These oligomer or polymer components may have reactive functional groups. The mass average molecular weight of the oligomer or polymer component is preferably from 2,000 to 30,000, more preferably from 2,000 to 20,000. The mass average molecular weight here refers to the polystyrene conversion value measured by the GPC (gel permeation chromatography) method.

[0105] In the negative resist composition of the present disclosure, as long as the effects of the present disclosure are not impaired, additives having miscibility as desired, such as additional resins for improving the performance of the resist film, surfactants for improving coatability, dissolution inhibitors, plasticizers, stabilizers, colorants, anti-halation agents, etc. can be appropriately added and contained. In the non-chemically amplified negative resist composition of the present disclosure, the total content of the specific phenolic compound (A) and the organic basic compound (B) may be 90% by mass or more, 95% by mass or more, 97% by mass or more, or even 100% by mass based on the total solid content of the resist composition.

[0106] <Preparation of non-chemically amplified negative resist composition> The non-chemically amplified negative resist composition according to the present disclosure is usually prepared by uniformly mixing the specific phenolic compound (A), the organic basic compound (B) as required, and other additives in an organic solvent.

[0107] As the organic solvent, those generally used as the solvent for the resist can be used. For example, ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, diethylene glycol dimethyl ether, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran, etc. are preferable, and these solvents can be used alone or in combination. Further, it may contain alcohols such as isopropyl alcohol, ethyl alcohol, methyl alcohol, n-butyl alcohol, s-butyl alcohol, t-butyl alcohol, isobutyl alcohol, 2-methyl-1-pentanol, 4-methyl-2-pentanol, 2-methoxyethanol, 2-ethoxyethanol, 1-ethoxy-2-propanol, 1-methoxy-2-propanol, and aromatic solvents such as toluene and xylene. In the present disclosure, among these organic solvents, in addition to diethylene glycol dimethyl ether, cyclohexanone, cyclopentanone, 1-ethoxy-2-propanol, and ethyl lactate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and their mixed solvents, which are safe solvents, are preferably used. The amount of the solvent in the resist composition is not particularly limited, and it is appropriately set according to the coating film thickness at a concentration that can be coated on a substrate or the like. Generally, the solvent is used so that the solid content concentration of the resist composition is preferably in the range of 0.5 to 20% by mass, more preferably 0.5 to 15% by mass.

[0108] The non-chemically amplified negative resist composition according to the present disclosure preferably has a water content adjusted to 0.5% by mass or less, more preferably 0.01 to 0.5% by mass, and even more preferably 0.15 to 0.30% by mass. The water content can be adjusted, for example, by appropriately drying the materials used or by drying the preparation atmosphere (for example, a humidity of 50% or less).

[0109] In addition, the non-chemically amplified negative resist composition according to the present disclosure has an acid component content of 1×10 -3 milli-equivalent / g or less, more preferably 5×10 -4 milli-equivalent / g or less. The acid component content can be adjusted, for example, by treating the solution of the materials used or the composition solution with an ion exchange resin, or by washing the solution of the materials used with pure water. The acid component content can be determined by non-aqueous potential difference measurement. The non-chemically amplified negative resist composition according to the present disclosure is preferably filtered and used after being prepared.

[0110] In addition, the non-chemically amplified negative resist composition used in the present disclosure can achieve a slope γ of 2.0 or less at the rising edge of the resist film thickness in the sensitivity curve (contrast curve) of the exposure dose and the resist film thickness after development. Furthermore, by containing the organic basic compound (B), the slope γ can be further reduced to 1.0 or less. Therefore, it is easy to precisely control the height of the convex portion according to the magnitude of the exposure dose, and it is suitable for a negative resist composition for tone exposure. Here, the slope γ is a value calculated as the slope of the approximate straight line in the range of the resist film thickness (Normalized thickness) of 0.0 - 0.5 after development, and the exposure dose (Dose) at that time is calculated in mC / cm 2 at that time.

[0111] (2) A step of applying the negative resist composition onto a substrate and then performing a heat treatment to form a resist film In this step, first, the non-chemically amplified negative resist composition is applied onto a substrate. "On the substrate" means not only when directly applied to the substrate, but also when there is another layer such as an adhesion layer on the substrate, it may be on the other layer. The substrate and the adhesion layer may be the same as those described in the three-dimensional mold above. The coating method is not particularly limited as long as it can uniformly coat the non-chemically amplified negative resist composition on the substrate surface, and various methods such as spray method, roll coating method, slit coating method, spin coating, etc. can be used.

[0112] Next, pre-baking (PAB) is performed on the non-chemically amplified negative resist composition coated on the substrate to remove the organic solvent and form a resist film. The temperature of the pre-baking can be appropriately determined according to the components of the composition, the usage ratio, the type of the organic solvent, etc., and is usually 80~160°C, preferably 90~150°C. Also, the pre-baking time is usually about 30 seconds to 15 minutes. The thickness of the resist film may be appropriately adjusted according to the concavo-convex pattern shape corresponding to the use of the three-dimensional mold and is not particularly limited. The thickness of the resist film may be, for example, 0.1μm~5.0μm, and further may be 1.0μm~2.0μm.

[0113] 3. The step of subjecting the resist film to tone exposure and development (1) The step of tone exposure In this step, first, tone exposure is performed on the resist film. Tone exposure means supplying energy to cure the negative resist composition in a tone manner. As the tone exposure method, a known method can be appropriately selected and used. For example, using an exposure device such as an electron beam lithography device or an EUV exposure device, exposure may be performed through a tone mask having a predetermined pattern shape, or selective tone exposure may be performed by direct irradiation of an electron beam without passing through a tone mask, such as by drawing.

[0114] As the tone mask, a known tone mask can be appropriately selected and used. Examples of the tone mask include a halftone mask, a slit mask (gray tone mask), and the like. In addition, as a method of selectively performing tone exposure by direct irradiation of an electron beam without passing through a tone mask, for example, by using focus adjustment of exposure, the tone exposure function of a drawing exposure machine, etc., the acceleration voltage and the exposure amount can be changed to perform tone exposure. By performing tone exposure on the resist film, the resist composition in the resist film proceeds with a curing reaction according to the magnitude of the exposure amount.

[0115] The exposure light source is not particularly limited, and can be performed using an ArF excimer laser, a KrF excimer laser, an F2 excimer laser, EUV (Extreme Ultraviolet), an electron beam, an X-ray, an ion beam such as helium or hydrogen, etc.

[0116] Next, after exposure, post-exposure bake (PEB) may be performed. Since the non-chemically amplified resist composition does not substantially contain a photoacid generator, there is no need to perform post-exposure heating for acid diffusion. However, for the non-chemically amplified negative resist composition of the present disclosure, post-exposure heating may improve the sensitivity, so it is preferable to perform post-exposure heating as appropriate. The conditions for the PEB treatment are usually at a temperature of 50 to 160 °C for about 0.1 to 15 minutes.

[0117] (2) Development step Next, the substrate provided with the resist film after tone exposure, which has been subjected to PEB treatment as necessary above, is developed using an alkaline developer to remove the unexposed portion and the uncured portion of the exposure light in the resist film. Examples of the development method include a spray method, a slit method, a liquid pool method, a dipping method, a rocking immersion method, and the like. In addition, as the alkaline developer for the non-chemically amplified negative resist composition used in the present disclosure, inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, primary amines such as ethylamine and n-propylamine, secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldimethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, and choline, and aqueous solutions of alkalis such as cyclic amines such as pyrrole and piperidine can be used. Furthermore, an appropriate amount of alcohols such as isopropyl alcohol and surfactants such as nonionic surfactants can be added to the aqueous solutions of the above alkalis and used. Among these alkaline developers, quaternary ammonium salts are preferred, and more preferably, aqueous solutions of tetramethylammonium hydroxide and choline.

[0118] When an aqueous solution of tetramethylammonium hydroxide (TMAH) is used as the alkaline developer, the concentration of the aqueous solution of tetramethylammonium hydroxide is preferably 0.1% to 25%, more preferably 0.2% to 5%, and particularly preferably 0.2% to 2.38%. An aqueous solution of tetramethylammonium hydroxide with a concentration of 2.38% is generally the most readily available in the semiconductor industry. Also, when the concentration of the aqueous solution of tetramethylammonium hydroxide is less than 0.1%, the developer is neutralized by carbon dioxide in the air, and it becomes difficult to obtain products stably due to fluctuations in sensitivity.

[0119] After the development process, a rinsing process is performed to wash away the alkaline developer on the substrate and the resist composition dissolved by the alkaline developer, and then dried to obtain a resist pattern. The resist pattern thus obtained becomes an uneven pattern layer having an uneven pattern shape including convex portions with different heights and / or convex portions having inclined surfaces, and the three-dimensional mold of the present disclosure can be manufactured.

[0120] II. Negative resist composition for tone exposure Another embodiment of the present disclosure provides a negative resist composition for tone exposure, which contains a phenolic compound (A) having two or more phenolic hydroxyl groups in one molecule and two or more substituents selected from the group consisting of hydroxymethyl groups and alkoxymethyl groups at the ortho positions of the phenolic hydroxyl groups, and having a molecular weight of 400 to 2500, and an organic basic compound (B), wherein the content of the phenolic compound (A) in the total solid content of the negative resist composition is 70% by weight or more, and the negative resist composition is non-chemically amplified and substantially does not contain an acid generator.

[0121] The negative resist composition for tone exposure according to one embodiment of the present disclosure contains the specific phenolic compound (A) and the organic basic compound (B), and since the content of the phenolic compound (A) in the total solid content of the negative resist composition is 70% by weight or more and it is non-chemically amplified and substantially does not contain an acid generator, as described above, the organic basic compound (B) can be controllably made less likely to cause a condensation reaction between the specific phenolic compounds (A), and it becomes easier to precisely control the height of the convex portions in proportion to the amount of exposure, improving the tone exposure performance.

[0122] The negative resist composition for tone exposure according to one embodiment of the present disclosure may be the same as the negative resist composition containing the organic basic compound (B) among the negative resist compositions described in the method for manufacturing the three-dimensional mold according to one embodiment of the present disclosure, and thus detailed description here is omitted.

[0123] The negative resist composition for grayscale exposure according to one embodiment of the present disclosure can be used not only for manufacturing the three-dimensional mold as described above, but also for applications such as semiconductor integrated circuits, recording media, MEMS, and optical devices.

[0124] Note that the present disclosure is not limited to the above embodiments. The above embodiments are examples, and any configuration that has substantially the same configuration as the technical idea described in the claims of the present disclosure and exhibits the same operational effects is included in the technical scope of the present disclosure.

Examples

[0125] Hereinafter, the present disclosure will be specifically described with reference to examples. These descriptions do not limit the present disclosure. In the production examples, the confirmation of the structure and physical properties was performed using the following apparatuses. MALDI-TOF MS: REFLEX II manufactured by BRUKER 1 H-NMR: JEOL JNM-LA400WB manufactured by JEOL Ltd. Purity: Measured by high performance liquid chromatography (HPLC) (LC-10ADvp manufactured by Shimadzu Corporation) under the following conditions (temperature: 40 ° C, flow rate: 1.0 mL / min, column: VP-ODS (4.7 mm × 150 mm), detector SPD-M10Avp, mobile phase: acetonitrile / water). Glass transition temperature (Tg): Using a differential thermal analyzer (“DSC-60” manufactured by Shimadzu Corporation), after heating about 4 mg of the pattern forming material to 200 ° C at a rate of 10 ° C / min and cooling to room temperature, and then heating to 200 ° C again at a rate of 10 ° C / min, the glass transition temperature was determined as the intersection of the two tangent lines of the smooth curve before and after the inflection temperature part of the DTA curve. When no inflection point of the DTA curve corresponding to the glass transition temperature was observed up to 200 ° C, Tg was determined to be 200 ° C or higher.

[0126] <Synthesis Example 1: Synthesis of phenolic compound (A-01)> To a solution consisting of 20 mL of a 10 mass% potassium hydroxide aqueous solution and 20 mL of ethanol, 6.3 g (10 mmol) of a phenolic compound (TekOC-4HBPA: Honshu Chemical Industry Co., Ltd.) represented by the following chemical formula (1) was added, and the mixture was stirred and dissolved at room temperature. To this solution, 7.0 mL (80 mmol) of a 37% formalin aqueous solution was slowly added at room temperature. Further, after stirring at 40 °C for 24 hours under a nitrogen atmosphere, the mixture was poured into 200 mL of water in a beaker. While cooling this in an ice bath, a 2.0 wt% acetic acid aqueous solution was slowly added until the pH reached 5.0. The precipitate was filtered off, washed thoroughly with water, and then dried. Purification was carried out by high performance liquid chromatography to obtain 5.8 g of a phenolic compound (A-01) represented by the following chemical formula (2). The structure confirmation of the obtained phenolic compound 1 (A-01) was 1 performed by 1H-NMR spectrum and MALDI-TOF MS. The glass transition temperature (Tg) was determined by differential scanning calorimetry. The analysis results are shown in Table 1 below.

[0127]

Chemical formula

[0128]

Chemical formula

[0129] 1 1H-NMR: 0.44 (6H, -CH3), 1.09 - 1.67 (14H, c Hex), 2.03 (12H, Ph-CH3), 2.64 - 2.67 (4H, c Hex), 4.44 - 4.51 (8H, Ph-CH2-OH), 5.19 - 5.25 (4H, Ph-CH2-OH), 6.74 - 7.02 (8H, Aromatic H), 8.10 - 8.13 (4H, Ph-OH) Purity: 92% MALDI-TOF MS: 752.97 Glass transition temperature (Tg): 200 °C or higher

[0130] [Production Example 1: Negative Resist Composition 1 for Grayscale Exposure of the Present Disclosure] 25.17% by mass of the phenolic compound (A) obtained in Synthesis Example 1, 3.55% by mass of 3-hydroxy-piperidine as the organic basic compound (B), and 71.28% by mass of the organic solvent (propylene glycol monomethyl ether) were blended to form a homogeneous solution, and the sample solution was filtered through a 0.1 μm Teflon (registered trademark) filter to prepare the non-chemically amplified negative resist composition of Production Example 1.

[0131] [Production Example 2: Negative Resist Composition 2 for Grayscale Exposure of the Present Disclosure] 25.17% by mass of the phenolic compound (A) obtained in Synthesis Example 1, 3.55% by mass of 4-hydroxy-piperidine as the organic basic compound (B), and 71.28% by mass of the organic solvent (propylene glycol monomethyl ether) were blended to form a homogeneous solution, and the sample solution was filtered through a 0.1 μm Teflon (registered trademark) filter to prepare the non-chemically amplified negative resist composition of Production Example 2.

[0132] [Production Example 3: Non-Chemically Amplified Negative Resist Composition 3] Further, the phenolic compound (A) and the organic solvent were made into a homogeneous solution in the blending amounts shown in Table 2 and filtered through a 0.1 μm Teflon (registered trademark) filter to prepare the non-chemically amplified negative resist composition of Production Example 3. Note that the non-chemically amplified negative resist composition of Production Example 3 does not contain the organic basic compound (B), so it does not correspond to the negative resist composition for grayscale exposure of another embodiment of the present disclosure.

[0133] [Evaluation of Non-Chemically Amplified Negative Resist Composition (Sensitivity Curve)] Each non-chemically amplified negative resist composition was uniformly coated on a 6-inch silicon substrate using a spinner, and pre-baked (PAB) at 110 °C for 60 seconds to form a resist film with a thickness of 2 μm. For the above resist film, using an electron beam lithography apparatus (acceleration voltage: 100 keV), exposure was performed with varying exposure amounts within a 1 mm square. After the exposure, development was carried out for 60 seconds with a 2.38% TMAH aqueous solution (at 23 °C), and rinsing was performed for 60 seconds with pure water to obtain a resist cured pattern corresponding to the exposure amount. The sensitivity was measured by a fine shape measuring instrument (ET4000 manufactured by Kosaka Laboratory Ltd.) for the height of the resist cured product with respect to the exposure amount, and a sensitivity curve (contrast curve) of the exposure amount and the resist film thickness after development, as shown in FIG. 12, was obtained.

[0134] [Example 1: Production of a three-dimensional mold] Using the negative resist composition 1 for tone exposure of the present disclosure obtained in Production Example 1, an uneven pattern shape was formed by the method shown below, and a three-dimensional mold was produced. (1) Coating of the resist The negative resist composition for tone exposure was uniformly coated on a 6-inch silicon substrate using a spinner, and pre-baked (PAB) at 110 °C for 60 seconds to form a resist film with a thickness of 2 μm. (2) Formation of the resist pattern For the above resist film, using an electron beam lithography apparatus (acceleration voltage: 100 keV), specifically, from the sensitivity curve obtained in advance, layers were allocated as layers for each resist height finally to be formed, and appropriate exposure amounts were set for each layer and exposure was performed. After the exposure, development was carried out for 60 seconds with a 2.38% TMAH aqueous solution (at 23 °C), and rinsing was performed for 60 seconds with pure water to form an uneven pattern. The cross-sectional shape of the uneven pattern was observed with a scanning electron microscope (SEM) (manufactured by ZEISS). FIG. 13 shows a scanning electron micrograph of the cross-section of the three-dimensional mold of Example 1.

[0135] [Example 2: Production of a three-dimensional mold] Using the negative resist composition for grayscale exposure 2 of the present disclosure obtained in Production Example 2, an uneven pattern shape was formed by the method shown below, and a three-dimensional mold was manufactured. (1) Coating of resist The negative resist composition for grayscale exposure was uniformly coated on a 6-inch silicon substrate using a spinner, and pre-baked (PAB) at 110 °C for 60 seconds to form a resist film with a thickness of 2 μm. (2) Formation of resist pattern With respect to the above resist film, using an electron beam lithography apparatus (acceleration voltage 100 keV), specifically, from the sensitivity curve obtained in advance, it was allocated as a layer for each resist height finally to be formed, and exposure was performed by setting an appropriate exposure amount for the layer. After the completion of the drawing, development was performed with a 2.38% TMAH aqueous solution (23 degrees) for 60 seconds, and rinsing was performed with pure water for 60 seconds to form an uneven pattern. The cross-sectional shape of the uneven pattern was observed with a scanning electron microscope (SEM) (manufactured by ZEISS). FIG. 14 shows a scanning electron micrograph of the cross-section of the three-dimensional mold of Example 2.

[0136] Table 1 shows the measurement results of the cross-sectional shapes of the three-dimensional molds of Examples 1 and 2.

[0137] [Table 1]

[0138] [Table 2]

[0139] [Summary of results] From the sensitivity curves of Production Examples 1 to 3 shown in FIG. 12, it has been shown that in the non-chemically amplified negative resist compositions of Production Examples 1 to 3 containing a specific amount of the specific phenolic compound (A) used in the method for producing a three-dimensional mold of the present disclosure, it is suitable for tone exposure because the height of the convex portion can be easily controlled according to the amount of exposure. In particular, the negative resist composition for tone exposure of another embodiment of the present disclosure, which contains an organic basic compound (B) and is non-chemically amplified, can further reduce the inclination γ, so that the height of the convex portion can be easily controlled with high precision according to the amount of exposure, and it has been shown that it is suitable for the negative resist composition for tone exposure.

[0140] Referring to FIGS. 13 and 14, the three-dimensional mold produced by the production method of the present disclosure can form convex portions having inclined surfaces with a small adjacent convex portion interval in its cross-sectional shape, and the curvature radius of the arc of the rising portion at the lower part of the convex portion becomes small, and the ratio of the curvature radius (R) to the height (H) of the convex portion is also small. It has been clarified that a three-dimensional mold having an uneven pattern close to an ideal shape can be produced.

Explanation of Signs

[0141] 1 Convex portion 2 Concave portion 3 Uneven pattern shape 5,5’ Ends of the convex portion 10 Uneven pattern layer 20 Substrate 30 Adhesion layer 40 Exposure 100 Three-dimensional mold < / mw> < / mw>

Claims

Claim 1 A negative resist composition containing a phenolic compound (A) having two or more phenolic hydroxyl groups in one molecule and having two or more substituents selected from the group consisting of hydroxymethyl groups and alkoxymethyl groups at the ortho position of the phenolic hydroxyl group, with a molecular weight of 400 to 2500, and an organic basic compound (B), wherein the content of the phenolic compound (A) in the total solid content of the negative resist composition is 70% by weight or more, and the content of the acid generator is less than 1 part by mass with respect to 100 parts by mass of the phenolic compound (A), and which is a non-chemically amplified type negative resist composition for tone exposure. Claim 2 The negative resist composition for tone exposure according to claim 1, wherein the organic basic compound (B) is an organic basic compound containing a hydroxyl group. Claim 3 The negative resist composition for tone exposure according to claim 1 or 2, wherein the organic basic compound (B) has a molecular weight of less than 400.

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