KR102296818B1 - Semiconductor resist composition, and method of forming patterns using the composition - Google Patents

Abstract

화학식 1에 대한 구체적인 내용은 명세서 상에서 정의된 것과 같다. The present disclosure relates to a composition for a semiconductor photoresist comprising an organometallic compound represented by the following Chemical Formula 1 and a solvent, and a pattern forming method using the same.
[Formula 1]

Specific details of Chemical Formula 1 are as defined in the specification.

Description

A composition for a semiconductor resist, and a pattern formation method using the same

The present disclosure relates to a composition for a semiconductor resist, a method for forming a pattern using the same, and a method for manufacturing a semiconductor device.

EUV (extreme ultraviolet light) lithography is attracting attention as one of the elemental technologies for manufacturing next-generation semiconductor devices. EUV lithography is a pattern forming technique using EUV light having a wavelength of 13.5 nm as an exposure light source. According to EUV lithography, it has been demonstrated that an extremely fine pattern (for example, 20 nm or less) can be formed in the exposure step of a semiconductor device manufacturing process.

Implementation of extreme ultraviolet (EUV) lithography requires the development of compatible photoresists that can perform at sub- 16 nm spatial resolutions. Currently, traditional chemically amplified (CA) photoresists have the resolution, photospeed, and feature roughness (also called line edge roughness or LER) for next-generation devices. efforts are being made to meet the specifications for

The intrinsic image blur due to acid catalyzed reactions taking place in these polymeric photoresists limits resolution at small feature sizes, which e-beam This is a fact that has long been known in lithography. Chemically amplified (CA) photoresists are designed for high sensitivity, but because their typical elemental makeup lowers the absorbance of photoresists at a wavelength of 13.5 nm, which in turn reduces sensitivity, may suffer more under EUV exposure.

Chemically amplified CA photoresists may also suffer from roughness issues at small feature sizes, due in part to the nature of acid catalyzed processes, line edge roughness as photospeed decreases. (LER) has been shown to increase experimentally. Due to the drawbacks and problems of CA photoresists, there is a need in the semiconductor industry for a new type of high performance photoresists.

One embodiment provides a composition for a semiconductor photoresist that has excellent etch resistance and sensitivity, is stable to moisture, and is easy to handle.

Another embodiment provides a pattern forming method using the composition for a semiconductor photoresist.

The composition for a semiconductor photoresist according to an embodiment includes an organometallic compound represented by the following Chemical Formula 1, and a solvent.

[Formula 1]

In Formula 1,

R is a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, or a substituted or unsubstituted C6 to C20 aryl group,

X, Y, and Z are each independently an organic group having a double bond at the β-position carbon from Sn.

A pattern forming method according to another embodiment includes forming an etch target film on a substrate, applying the above-described composition for a semiconductor photoresist on the etch target film to form a photoresist film, patterning the photoresist film to form a photoresist pattern forming, and etching the etch target layer using the photoresist pattern as an etch mask.

The composition for a semiconductor photoresist according to an embodiment is stable to moisture, so storage stability is high, and handling is easy. Also, the semiconductor photoresist prepared from the composition has excellent etch resistance and sensitivity. It is possible to provide an excellent photoresist pattern that is excellent and does not collapse even at a high aspect ratio.

1 to 5 are cross-sectional views for explaining a pattern forming method using a composition for a semiconductor resist according to an exemplary embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in describing the present description, descriptions of already known functions or configurations will be omitted in order to clarify the gist of the present description.

In order to clearly explain the present description, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification. In addition, since the size and thickness of each component shown in the drawings are arbitrarily indicated for convenience of description, the present description is not necessarily limited to the illustrated bar.

In order to clearly express various layers and regions in the drawings, the thicknesses are enlarged. In addition, in the drawings, thicknesses of some layers and regions are exaggerated for convenience of description. When a part, such as a layer, film, region, plate, etc., is "on" or "on" another part, it includes not only cases where it is "directly on" another part, but also cases where there is another part in between.

In the present description, "substituted" means that a hydrogen atom is deuterium, a halogen group, a hydroxyl group, a cyano group, a nitro group, -NRR' (wherein R and R' are each independently hydrogen, a substituted or unsubstituted C1 to C30 saturated or an unsaturated aliphatic hydrocarbon group, a substituted or unsubstituted C3 to C30 saturated or unsaturated alicyclic hydrocarbon group, or a substituted or unsubstituted C6 to C30 aromatic hydrocarbon group), -SiRR'R" (where R, R', and R" is each independently hydrogen, a substituted or unsubstituted C1 to C30 saturated or unsaturated aliphatic hydrocarbon group, a substituted or unsubstituted C3 to C30 saturated or unsaturated alicyclic hydrocarbon group, or a substituted or unsubstituted C6 to C30 aromatic hydrocarbon group), C1 to C30 alkyl group, C1 to C10 haloalkyl group, C1 to C10 alkylsilyl group, C3 to C30 cycloalkyl group, C6 to C30 aryl group, C1 to C20 alkoxy group, or a combination thereof means that "Unsubstituted" means that a hydrogen atom remains as a hydrogen atom without being substituted with another substituent.

In the present description, "hetero" means that, unless otherwise defined, one functional group contains 1 to 3 heteroatoms selected from the group consisting of N, O, S and P, and the remainder is carbon. .

As used herein, the term "alkyl group" refers to a straight-chain or branched-chain aliphatic hydrocarbon group, unless otherwise defined. The alkyl group may be a “saturated alkyl group” that does not contain any double or triple bonds.

The alkyl group may be a C1 to C20 alkyl group. For example, the alkyl group may be a C1 to C10 alkyl group, a C1 to C8 alkyl group, a C1 to C6 alkyl group, or a C1 to C4 alkyl group. For example, the C1 to C4 alkyl group can be a methyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, or t-butyl group.

As used herein, the term "alkenyl group", unless otherwise defined, is a straight or branched aliphatic hydrocarbon group, and refers to an aliphatic unsaturated alkenyl group containing one or more double bonds. do.

As used herein, the term "heteroalkenyl group" means that at least one of the carbon atoms constituting the alkenyl group is substituted with a hetero atom selected from the group consisting of N, O, S, and P.

As used herein, the term “alkylene group” refers to a divalent straight-chain or branched-chain aliphatic hydrocarbon group, unless otherwise defined.

As used herein, the term “cycloalkylene group” refers to a divalent cyclic aliphatic hydrocarbon group unless otherwise defined.

As used herein, the term "heteroalkylene group" means that at least one carbon atom constituting the alkylene group is substituted with a hetero atom selected from the group consisting of N, O, S and P.

As used herein, the term "cycloalkyl group" refers to a monovalent cyclic aliphatic saturated hydrocarbon group unless otherwise defined.

The cycloalkyl group may be a C3 to C20 cycloalkyl group, for example, a C3 to C12 cycloalkyl group, a C3 to C8 cycloalkyl group, a C3 to C6 cycloalkyl group, a C3 to C5 cycloalkyl group, or a C3 or C4 cycloalkyl group. For example, the cycloalkyl group may be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, or a cyclohexyl group, but is not limited thereto.

As used herein, "cycloalkenyl group" refers to a monovalent cyclic aliphatic hydrocarbon group including one or more double bonds, unless otherwise defined.

In the present description, the term "heterocycloalkenyl group" means that at least one carbon atom constituting the cycloalkenyl group is substituted with a hetero atom selected from the group consisting of N, O, S and P.

In the present description, "aryl group" means a substituent in which all elements of a cyclic substituent have p-orbitals, and these p-orbitals form a conjugate, monocyclic or fusion ring polycyclic (ie, rings that share adjacent pairs of carbon atoms) functional groups.

In the present description, the "β-position carbon" refers to the carbon in the second position based on the functional group. Thus, "the β-position carbon from Sn" means the carbon in the second position from Sn.

The composition for a semiconductor photoresist according to an embodiment of the present invention includes an organometallic compound and a solvent, and the organometallic compound is represented by the following formula (1).

[Formula 1]

In Formula 1,

R is a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, or a substituted or unsubstituted C6 to C20 aryl group,

X, Y, and Z are each independently an organic group having a double bond at the β-position carbon from Sn.

The compound represented by Formula 1 is an organotin compound, and tin strongly absorbs extreme ultraviolet light at 13.5 nm and thus has excellent sensitivity to light having high energy. R may impart photosensitivity to the compound represented by Formula 1, and X, Y, and Z may determine solubility of the compound.

Specifically, it is thought that X, Y, and Z each include a double bond at the β-position carbon from Sn, thereby increasing the solubility of the compound represented by Formula 1 in a solvent. In addition, the X, Y, and Z, each containing a double bond at the β-position carbon from Sn, is thermally decomposed at a low temperature of 100 ° C to 150 ° C to form a metal (Sn)-oxygen (O) bond to the Sn element I think it can be given. Accordingly, when the composition according to an embodiment comprising the compound represented by Formula 1 and a solvent is coated on a substrate or the like and then heated to a temperature of 100° C. to 150° C., the X, Y, and Z are from Sn, respectively. It is thought to dissociate and instead form a bond between Sn and oxygen to form an organotin oxide hydroxide compound.

In addition, when R is exposed to extreme ultraviolet light, the Sn-R bond is dissociated to generate a radical, The radicals thus generated initiate a polycondensation reaction between organotin oxide hydroxide compounds having Sn-O bonds formed by thermal decomposition of X, Y, and Z, respectively, so that a semiconductor photoresist is formed from the composition. I think.

On the other hand, the X, Y, and Z do not react sensitively to moisture by including a double bond at the β-position carbon from Sn, respectively, and thus the storage stability of the composition may be excellent. Accordingly, the composition according to the exemplary embodiment has excellent storage stability and relatively easy handling, and the semiconductor photoresist prepared therefrom has excellent sensitivity and limit resolution, and there may be no pattern collapse even at a high aspect ratio.

For example, R may be selected from a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C12 cycloalkyl group, or a substituted or unsubstituted C6 to C12 aryl group, and in Formula 1, The X, Y, and Z are, each independently, an organic group having a double bond at the β-position carbon from Sn, for example, a substituted or unsubstituted C3 having a double bond at the β-position carbon from Sn to C12 alkenyl group, a substituted or unsubstituted C3 to C10 heteroalkenyl group having a double bond at the β-position carbon from Sn, a substituted or unsubstituted C3 to C12 cyclo having a double bond at the β-position carbon from Sn It may be an alkenyl group, or a substituted or unsubstituted C3 to C10 heterocycloalkenyl group having a double bond at the β-position carbon from Sn.

Wherein X, Y, and Z are all organic groups having the same structure, all organic groups having different structures, or two of X, Y, and Z are the same structure and the other one may be an organic group having a different structure, Even in the same or different structures, they are all the same in terms of having a double bond at the β-position carbon from Sn.

In one embodiment, the organometallic compound may be represented by at least one of Chemical Formula 2 and Chemical Formula 3 below.

[Formula 2]

In Formula 2,

R is a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, or a substituted or unsubstituted C6 to C20 aryl group,

A, B, and C are each independently hydrogen, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, or a substituted or unsubstituted C6 to C20 aryl group.

[Formula 3]

In Formula 3,

R is a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, or a substituted or unsubstituted C6 to C20 aryl group,

D is a substituted or unsubstituted C1 to C4 alkylene group, a substituted or unsubstituted C3 to C6 alkenylene group, or a substituted or unsubstituted C1 to C3 heteroalkylene group.

R in Formulas 2 and 3 may be any one selected from a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C12 cycloalkyl group, or a substituted or unsubstituted C6 to C12 aryl group, For example, R may be any one selected from a substituted or unsubstituted C1 to C4 alkyl group, a substituted or unsubstituted C3 to C6 cycloalkyl group, or a substituted or unsubstituted C6 to C10 aryl group. In one embodiment, R is a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, a sec-butyl group, an isobutyl group, a t-butyl group, a straight or branched pentyl group, a straight or branched hexyl group, cyclo It may be a C1 to C10 alkyl group substituted with a propyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a C3 to C6 cycloalkyl group, or a C1 to C10 alkyl group substituted with a phenyl group, but is not limited thereto.

A, B, and C are each independently selected from hydrogen, a substituted or unsubstituted C1 to C8 alkyl group, a substituted or unsubstituted C3 to C8 cycloalkyl group, or a substituted or unsubstituted C6 to C9 aryl group may be any one of the following, for example, a straight-chain or branched C1 to C6 alkyl group, C3 to C6 cycloalkyl group, or phenyl group, but is not limited thereto.

In Formula 2, at least one of the two hydrogens bonded to the terminal carbon of the double bond is a substituted or unsubstituted C1 to C8 alkyl group, a substituted or unsubstituted C3 to C8 cycloalkyl group, or a substituted or unsubstituted C6 to C9 may be substituted with an aryl group. When the hydrogen bonded to the terminal carbon of the double bond is substituted with a substituted or unsubstituted C1 to C8 alkyl group, a substituted or unsubstituted C3 to C8 cycloalkyl group, or a substituted or unsubstituted C6 to C9 aryl group, the double bond It may have any structure of cis, trans, E structure, or Z structure based on .

In one embodiment, D may be a substituted or unsubstituted C1 to C3 alkylene group, a substituted or unsubstituted C3 to C5 alkenylene group, or a substituted or unsubstituted C1 or C2 heteroalkylene group.

When D is a substituted or unsubstituted C1 to C3 heteroalkylene group, D is at least one hetero element selected from oxygen, nitrogen, phosphorus, and sulfur, wherein the hetero element in each ring including D The total number may be two or less.

For example, the organometallic compound according to the exemplary embodiment may be represented by at least one of the following Chemical Formulas 4 to 7.

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

In the case of a generally used organic resist, the etch resistance is insufficient, and there is a risk that the pattern may collapse at a high aspect ratio. On the other hand, when using a conventional inorganic resist, for example, a metal oxide compound, it is difficult to handle because a mixture of sulfuric acid and hydrogen peroxide having high corrosiveness is used, storage stability is poor, and structural change to improve performance as a complex mixture is relatively difficult. It is difficult, and there is a problem in that a developing solution having a high concentration must be used. In addition, some of the conventional inorganic resists contain ligands sensitive to moisture or oxygen, so handling is difficult and storage stability is not good.

On the other hand, the composition for a semiconductor resist according to an embodiment, as described above, the organometallic compound includes an organic group having a double bond at the β-position carbon from the central metal atom, Sn, so that the existing organic and/or inorganic resist It has relatively high etch resistance, is stable to moisture, has good storage stability, has excellent sensitivity, and is easy to handle. In addition, the pattern formed using the composition for semiconductor resist according to the embodiment may not collapse even at a high aspect ratio.

In the semiconductor resist composition according to an embodiment, the organometallic compound represented by Formula 1 is 0.01 wt% to 10 wt%, for example, 0.05 wt% to 10 wt%, based on the total weight of the composition, for example For example, 0.1% to 10% by weight, such as 0.3% to 10% by weight, such as 0.5% to 10% by weight, such as 1.0% to 10% by weight, for example, 1.5% to 10% by weight, such as 2.0% to 10% by weight, such as 2.5% to 10% by weight, such as 3.0% to 10% by weight, such as 3.5% by weight % to 10% by weight, such as 4.0% to 10% by weight, such as 4.5% to 10% by weight, such as 5.0% to 10% by weight, not limited When included in such an amount, storage stability is excellent, and thin film formation is easy.

The solvent included in the semiconductor resist composition according to the embodiment may be an organic solvent, for example, aromatic compounds (eg, xylene, toluene), alcohols (eg, 4-methyl-2-pentanol). , 4-methyl-2-propanol, 1-butanol, methanol, isopropyl alcohol, 1-propanol), ethers (eg, anisole, tetrahydrofuran), esters (n-butyl acetate, propylene glycol mono methyl ether acetate, ethyl acetate, ethyl lactate), ketones (eg, methyl ethyl ketone, 2-heptanone), mixtures thereof, and the like.

In an embodiment, the semiconductor resist composition may further include a resin in addition to the organometallic compound and the solvent.

The resin may be a phenolic resin including at least one aromatic moiety listed in Group 1 below.

[Group 1]

The resin may have a weight average molecular weight of 500 to 20,000.

The resin is 0.1% to 50% by weight, for example, 1% to 50% by weight, for example, 5% to 50% by weight, for example, 5% by weight based on the total content of the composition for the semiconductor resist. Weight % to 40% by weight, for example, 5% to 35% by weight, for example, 5% to 30% by weight may be included, but is not limited thereto.

When the resin is contained in the above content range, it may have excellent etch resistance and heat resistance.

The composition for a semiconductor resist according to the exemplary embodiment may further include, in some cases, an additive in addition to the above-described organometallic compound, solvent, and resin. Examples of the additive include a surfactant, a crosslinking agent, a leveling agent, or a combination thereof.

The surfactant may be, for example, an alkylbenzenesulfonic acid salt, an alkylpyridinium salt, polyethylene glycol, a quaternary ammonium salt, and the like, but is not limited thereto.

The crosslinking agent may be, for example, a melamine-based, substituted urea-based, or polymer-based crosslinking agent, but is not limited thereto. Crosslinking agents having at least two crosslinking substituents, for example, methoxymethylated glycouryl, butoxymethylated glycouryl, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine , methoxymethylated urea, butoxymethylated urea, methoxymethylated thiourea, or methoxymethylated thiourea may be used.

The leveling agent is for improving coating flatness during printing, and a known leveling agent available in a commercial manner may be used.

The amount of these additives used may be easily adjusted according to desired physical properties or may be omitted.

In addition, the composition for semiconductor resist may further use a silane coupling agent as an additive as an adhesion promoter in order to improve adhesion with a substrate. The silane coupling agent is, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyl trichlorosilane, vinyltris(β-methoxyethoxy)silane; or 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, p-styryl trimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldi ethoxysilane; A silane compound containing a carbon-carbon unsaturated bond such as trimethoxy[3-(phenylamino)propyl]silane may be used, but the present invention is not limited thereto.

In the composition for semiconductor resist, pattern collapse may not occur even when a pattern having a high aspect ratio is formed. Thus, for example, a fine pattern having a width of 5 nm to 100 nm, for example a fine pattern having a width of 5 nm to 80 nm, for example a fine pattern having a width of 5 nm to 70 nm, For example, a micropattern having a width of 5 nm to 50 nm, for example a micropattern having a width of 5 nm to 40 nm, for example, a micropattern having a width of 5 nm to 30 nm, for example For example, in order to form a fine pattern having a width of 5 nm to 20 nm, a photoresist process using light having a wavelength of 5 nm to 150 nm, for example, a photoresist using light having a wavelength of 5 nm to 100 nm process, eg a photoresist process using light with a wavelength of 5 nm to 80 nm, eg a photoresist process using light with a wavelength of 5 nm to 50 nm, eg, a wavelength between 5 nm and 30 nm It can be used in a photoresist process using light of, for example, a photoresist process using light having a wavelength of 5 nm to 20 nm. Therefore, using the composition for semiconductor resist according to the exemplary embodiment, extreme ultraviolet lithography using an EUV light source having a wavelength of about 13.5 nm may be implemented.

Meanwhile, according to another exemplary embodiment, a method of forming a pattern using the above-described composition for a semiconductor resist may be provided. For example, the manufactured pattern may be a photoresist pattern.

A pattern forming method according to an embodiment includes forming an etch target film on a substrate, forming a photoresist film by applying the above-described composition for semiconductor resist on the etch target film, and patterning the photoresist film to form a photoresist pattern and etching the etch target layer using the photoresist pattern as an etch mask.

Hereinafter, a method of forming a pattern using the above-described composition for a semiconductor resist will be described with reference to FIGS. 1 to 5 . 1 to 5 are cross-sectional views for explaining a pattern forming method using a composition for a semiconductor resist according to the present invention.

Referring to FIG. 1 , first, an object to be etched is prepared. An example of the object to be etched may be the thin film 102 formed on the semiconductor substrate 100 . Hereinafter, only the case where the object to be etched is the thin film 102 will be described. In order to remove contaminants and the like remaining on the thin film 102 , the surface of the thin film 102 is pre-cleaned. The thin film 102 may be, for example, a silicon nitride film, a polysilicon film, or a silicon oxide film.

Then, a composition for forming a resist underlayer film for forming the resist underlayer film 104 on the surface of the cleaned thin film 102 is coated by applying a spin coating method. However, one embodiment is not necessarily limited thereto, and various known coating methods, for example, spray coating, dip coating, knife edge coating, printing methods, such as inkjet printing and screen printing, may be used.

The resist underlayer coating process may be omitted, and the case of coating the resist underlayer film will be described below.

Thereafter, a drying and baking process is performed to form the resist underlayer 104 on the thin film 102 . The baking treatment may be performed at about 100 to about 500 °C, for example, about 100 °C to about 300 °C or about 100 °C to about 150 °C.

The resist underlayer film 104 is formed between the substrate 100 and the photoresist film 106, so that radiation reflected from the interface between the substrate 100 and the photoresist film 106 or from an interlayer hardmask is not intended. When the photoresist is scattered to the non-uniform photoresist area, it is possible to prevent the non-uniformity of the photoresist linewidth and disturb the pattern formability.

Referring to FIG. 2 , a photoresist layer 106 is formed by coating the above-described composition for semiconductor resist on the resist underlayer layer 104 . The photoresist film 106 may be in a form in which the semiconductor resist composition is coated on the thin film 102 formed on the substrate 100 and then cured through a heat treatment process.

More specifically, the step of forming the pattern using the composition for semiconductor resist is a process of applying the above-described composition for semiconductor resist on the substrate 100 on which the thin film 102 is formed by spin coating, slit coating, inkjet printing, etc. and drying the applied composition for a semiconductor resist to form the photoresist film 106 .

Since the composition for a semiconductor resist has already been described in detail, a redundant description thereof will be omitted.

Next, a first baking process of heating the substrate 100 on which the photoresist film 106 is formed is performed. The first baking process may be performed at a temperature of about 80 °C to about 120 °C.

Referring to FIG. 3 , the photoresist layer 106 is selectively exposed.

For example, examples of light that can be used in the exposure process include not only light having a short wavelength such as i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), but also EUV ( Light having a high energy wavelength such as Extreme UltraViolet (wavelength 13.5 nm) and E-Beam (electron beam) may be mentioned.

More specifically, the light for exposure according to an exemplary embodiment may be short-wavelength light having a wavelength range of 5 nm to 150 nm, and light having a high energy wavelength such as EUV (Extreme Ultraviolet; wavelength 13.5 nm), E-Beam (electron beam), etc. can

The exposed region 106a of the photoresist film 106 has a solubility different from that of the unexposed region 106b of the photoresist film 106 as a polymer is formed by a crosslinking reaction such as condensation between organometallic compounds. .

Next, a second baking process is performed on the substrate 100 . The second baking process may be performed at a temperature of about 90 °C to about 200 °C. By performing the second baking process, the exposed region 106a of the photoresist layer 106 becomes difficult to dissolve in a developer.

4 shows a photoresist pattern 108 formed by dissolving and removing the photoresist film 106b corresponding to the unexposed region using a developer. Specifically, by using an organic solvent such as 2-heptanone to dissolve and then remove the photoresist film 106b corresponding to the unexposed region, the photoresist pattern ( 108) is completed.

As described above, the developer used in the pattern forming method according to the exemplary embodiment may be an organic solvent. As an example of the organic solvent used in the pattern forming method according to an embodiment, ketones such as methyl ethyl ketone, acetone, cyclohexanone, 2-haptanone, cyclohexanone, 4-methyl-2-propanol, 1- Alcohols such as butanol, isopropanol, 1-propanol, and methanol, esters such as propylene glycol monomethyl ester acetate, ethyl acetate, ethyl lactate, n-butyl acetate, butyrolactone, and aromatics such as benzene, xylene and toluene compound, or a combination thereof.

However, the photoresist pattern according to the exemplary embodiment is not necessarily limited to being formed as a negative tone image, and may be formed to have a positive tone image. In this case, as a developer that can be used to form a positive tone image, a quaternary ammonium hydroxide composition such as tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, or a combination thereof, etc. can be heard

As described above, not only light having a wavelength such as i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), but also EUV (Extreme UltraViolet; wavelength 13.5 nm), The photoresist pattern 108 formed by exposure to light having high energy, such as an E-beam (electron beam), may have a width of 5 nm to 100 nm. For example, the photoresist pattern 108 may be 5 nm to 90 nm, 5 nm to 80 nm, 5 nm to 70 nm, 5 nm to 60 nm, 10 nm to 50 nm, 10 nm to 40 nm, 10 nm to 30 nm, and may be formed to a width of 10 nm to 20 nm.

On the other hand, the photoresist pattern 108 has a half-pitch of about 50 nm or less, for example 40 nm or less, for example 30 nm or less, for example 25 nm or less, and about 10 nm or less, It may have a pitch having a linewidth roughness of about 5 nm or less.

Next, the resist underlayer 104 is etched using the photoresist pattern 108 as an etching mask. The organic layer pattern 112 is formed through the etching process as described above. The formed organic layer pattern 112 may also have a width corresponding to the photoresist pattern 108 .

Referring to FIG. 5 , the exposed thin film 102 is etched by applying the photoresist pattern 108 as an etch mask. As a result, the thin film is formed as a thin film pattern 114 .

The thin film 102 may be etched, for example, by dry etching using an etching gas, and the etching gas may be, for example, CHF ₃ , CF ₄ , Cl ₂ , BCl _{3 ,} or a mixture thereof.

In the exposure process performed above, the thin film pattern 114 formed using the photoresist pattern 108 formed by the exposure process performed using the EUV light source may have a width corresponding to the photoresist pattern 108 . . For example, the photoresist pattern 108 may have a width of 5 nm to 100 nm. For example, the thin film pattern 114 formed by the exposure process performed using the EUV light source may be 5 nm to 90 nm, 5 nm to 80 nm, 5 nm to 70 nm, 5 like the photoresist pattern 108 . It may have a width of nm to 60 nm, 10 nm to 50 nm, 10 nm to 40 nm, 10 nm to 30 nm, 10 nm to 20 nm, and more specifically, may be formed to a width of 20 nm or less.

Hereinafter, the present invention will be described in more detail through examples related to the preparation of the composition for a semiconductor resist according to an embodiment. However, the present invention is not technically limited by the following examples.

Example

Synthesis Example 1

_{Dissolve Ph 3} SnCl (20 g, 51.9 mmol) in 70 ml of THF in a 250 mL two-necked round-bottom flask, and lower the temperature to 0 °C in an ice bath. Then, butyl magnesium chloride (BuMgCl) 1M THF solution (62.3mmol) is slowly added dropwise. After completion of the dropwise addition, the mixture was stirred at room temperature for 12 hours to obtain a compound represented by the following formula (A-1) in a yield of 85%.

[Formula A-1]

The compound of Formula A-1 (10 g, 24.6 mmol) _{was dissolved in 50 mL of CH 2} Cl ₂ , and 2M HCl diethyl ether solution (3 equivalents, 73.7 mmol) was slowly added dropwise at -78°C for 30 minutes. Thereafter, after stirring at room temperature for 12 hours, the solvent was concentrated and vacuum distilled to obtain a compound represented by the following Chemical Formula A-2 in a yield of 80%.

[Formula A-2]

The compound of Formula A-2 (5 g, 17.7 mmol) was dissolved in 50 ml of THF, and the temperature was lowered to 0 °C in an ice bath. Then, allyl magnesium chloride (allylMgCl) 2M THF solution (58 mmol) is slowly added dropwise. After completion of the dropwise addition, the mixture was stirred at room temperature for 12 hours to obtain a compound represented by the following Chemical Formula 4 in a yield of 90%.

[Formula 4]

Synthesis Example 2

_{Dissolve Ph 3} SnCl (20 g, 51.9 mmol) in 70 ml of THF in a 250 mL two-necked round-bottom flask, and lower the temperature to 0 °C in an ice bath. Then, butyl isopropyl magnesium chloride (i-PrMgCl) 2M THF solution (62.3 mmol) is slowly added dropwise. After completion of the dropwise addition, the mixture was stirred at room temperature for 12 hours to obtain a compound represented by the following Chemical Formula A-3 in a yield of 88%.

[Formula A-3]

The compound of Formula A-3 (10 g, 24.6 mmol) _{was dissolved in 50 mL of CH 2} Cl ₂ , and 2M HCl diethyl ether solution (3 equivalents, 73.7 mmol) was slowly added dropwise at -78°C for 30 minutes. Thereafter, after stirring at room temperature for 12 hours, the solvent was concentrated and vacuum distilled to obtain a compound represented by the following Chemical Formula A-4 in a yield of 75%.

[Formula A-4]

The compound of Formula A-4 of Synthesis Example 5 (5 g, 18.6 mmol) was dissolved in 50 ml of THF, and the temperature was lowered to 0° C. in an ice bath. Then, 2-methylallyl magnesium chloride (2-methylallyl MgCl) 0.5M THF solution (62 mmol) is slowly added dropwise. After completion of the dropwise addition, the mixture was stirred at room temperature for 12 hours to obtain a compound represented by the following Chemical Formula 5 in a yield of 90%.

[Formula 5]

Synthesis Example 3

In a 250 mL two-necked round bottom flask, Ph ₃ SnCl (20 g, 51.9 mmol) was dissolved in 70 mL of THF, and the temperature was lowered to 0 °C in an ice bath. Then, butyl neopentyl magnesium chloride 1M THF solution (62.3 mmol) is slowly added dropwise. After completion of the dropwise addition, the mixture was stirred at room temperature for 12 hours to obtain a compound represented by the following Chemical Formula A-5 in a yield of 76%.

[Formula A-5]

The compound of Formula A-5 (10 g, 24.6 mmol) _{was dissolved in 50 mL of CH 2} Cl ₂ , and 2M HCl diethyl ether solution (3 equivalents, 73.7 mmol) was dissolved in -78 Slowly add dropwise at ℃ for 30 minutes. Then, after stirring at room temperature for 12 hours, the solvent was concentrated and vacuum distilled to obtain a compound represented by the following Chemical Formula A-6 in a yield of 70%.

[Formula A-6]

The compound of Formula A-6 (5 g, 17.7 mmol) was dissolved in 50 ml of THF, and the temperature was lowered to 0 °C in an ice bath. Then, allyl magnesium chloride (allyl MgCl) 2M THF solution (58 mmol) is slowly added dropwise. After completion of the dropwise addition, the mixture was stirred at room temperature for 12 hours to obtain a compound represented by the following Chemical Formula 6 in a yield of 92%.

[Formula 6]

Synthesis Example 4

The compound of Formula A-4 of Synthesis Example 2 (5 g, 18.6 mmol) was dissolved in 50 ml of THF, and the temperature was lowered to 0° C. in an ice bath. Then, cyclohexenyl magnesium chloride (cyclohex-2-en-1-ylMgCl) 2M THF solution (62 mmol) is slowly added dropwise. After completion of the dropwise addition, the mixture was stirred at room temperature for 12 hours to obtain a compound represented by the following Chemical Formula 7 in a yield of 50%.

[Formula 7]

Example

Each of the compounds of Chemical Formulas 4 to 7 obtained in Synthesis Examples 1 to 4 were dissolved in 4-methyl-2-pentanol at a concentration of 2 wt%, and then with a 0.1 μm PTFE syringe filter. By filtration, compositions for semiconductor resists according to Examples 1 to 4 were prepared.

A 4-inch circular silicon wafer with a native-oxide surface was used as a substrate for thin film deposition, and the substrate was pretreated for 10 minutes under a UV ozone cleaning system. Thereafter, the resist composition for semiconductors according to Examples 1 to 4 was spin-coated on the pre-treated substrate at 1500 rpm for 30 seconds, and baked on a hot plate at 100° C. for 120 seconds (sintering after application, post-apply bake) , PAB) to form a thin film.

After coating and baking, the thickness of the film was measured through ellipsometry, and the measured thickness was about 20 nm.

comparative example

The compound of Formula A-6 synthesized in Synthesis Example 3 was dissolved in anhydrous 4-methyl-2-pentanol at a concentration of 2 wt%, and then filtered with a 0.1 μm PTFE syringe filter to filter the semiconductor A composition for resist was prepared.

Thereafter, a thin film was formed on the substrate through the same process as in the above-described embodiment with respect to the composition for a semiconductor resist according to the prepared comparative example.

After coating and baking, the thickness of the film was measured through ellipsometry, and the measured thickness was about 20 nm.

evaluation

A linear array of 50 circular pads having a diameter of 500 μm was projected onto the wafer coated with the resist compositions of Examples 1 to 4 and Comparative Examples using EUV light (Lawrence Berkeley National Laboratory Micro Exposure Tool, MET). The pad exposure time was adjusted so that an increased EUV dose was applied to each pad.

Thereafter, the resist and the substrate were exposed on a hot plate at 160° C. for 120 seconds, followed by post-exposure bake (PEB). The fired film was immersed in a developer (2-heptanone) for 30 seconds each, and then washed with the same developer for an additional 10 seconds to form a negative tone image, that is, to remove the coated portion not exposed to EUV light. Finally, the process was terminated by performing hot plate firing at 150° C. for 2 minutes.

The residual resist thickness of the exposed pad was measured using an ellipsometer. For each exposure amount, the remaining thickness was measured and graphed as a function of the exposure amount, and Dg (energy level at which development is completed) for each type of resist is shown in Table 1 below.

Meanwhile, for the compounds used in the above-described Examples and Comparative Examples, storage stability was evaluated according to the following criteria, and are shown together in Table 1 below.

[Storage Stability]

After visually observing the extent to which precipitation occurs when the resist compositions according to Examples 1 to 4 and Comparative Examples are left at room temperature (0° C. to 30° C.) for a specific period at room temperature (0° C. to 30° C.), store It was set as a possible criterion and evaluated in the following three steps.

○ : Precipitation or non-occurrence after 1 month

△: Precipitation occurs between 1 week and 1 month

X: Precipitation occurred less than 1 week

storage stability D _g (mJ/cm ² ) Example 1 ○ 25.28 Example 2 ○ 20.78 Example 3 ○ 25.28 Example 4 ○ 23.47 comparative example X not measurable

From the results of Table 1, it can be seen that the resist compositions for semiconductors according to Examples 1 to 4 exhibit excellent storage stability compared to Comparative Examples, and patterns formed using them also exhibit superior sensitivity compared to Comparative Examples. On the other hand, since the semiconductor resist composition according to the comparative example has poor storage stability in the 4-methyl-2-pentanol solvent, it can be confirmed that it is practically difficult to evaluate the storage stability and evaluate the pattern formation using the same.

100: substrate 102: thin film
104: resist underlayer film 106: photoresist film
106a: exposed area 106b: unexposed area
108: photoresist pattern 112: organic film pattern
114: thin film pattern

Claims (11)

A composition for a semiconductor photoresist comprising an organometallic compound represented by the following formula (1), and a solvent:
[Formula 1]

In Formula 1,
R is a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, or a substituted or unsubstituted C6 to C20 aryl group,
X, Y, and Z are each independently an organic group having a double bond at the β-position carbon from Sn. The composition of claim 1, wherein R is a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C12 cycloalkyl group, or a substituted or unsubstituted C6 to C12 aryl group. The method of claim 1, wherein X, Y, and Z are each independently a substituted or unsubstituted C3 to C12 alkenyl group having a double bond at the β-position carbon from Sn, a substituted or unsubstituted C3 to C10 hetero An alkenyl group, a substituted or unsubstituted C3 to C12 cycloalkenyl group, or a substituted or unsubstituted C3 to C10 heterocycloalkenyl group. A composition for a semiconductor photoresist. The method of claim 3, wherein the substituted or unsubstituted C3 to C10 heteroalkenyl group, and the substituted or unsubstituted C3 to C10 heterocycloalkenyl group comprises at least one element selected from oxygen, nitrogen, phosphorus, and sulfur. A composition for a semiconductor photoresist. The composition for a semiconductor photoresist of claim 1, wherein the composition for a semiconductor photoresist comprises a compound represented by the following Chemical Formula 2, a compound represented by Chemical Formula 3, or a combination thereof:
[Formula 2]

In Formula 2,
R is a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, or a substituted or unsubstituted C6 to C20 aryl group,
A, B, and C are each independently hydrogen, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, or a substituted or unsubstituted C6 to C20 aryl group;
[Formula 3]

In Formula 3,
R is a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, or a substituted or unsubstituted C6 to C20 aryl group,
D is a substituted or unsubstituted C1 to C4 alkylene group, a substituted or unsubstituted C3 to C6 alkenylene group, or a substituted or unsubstituted C1 to C3 heteroalkylene group. According to claim 5, wherein the substituted or unsubstituted C1 to C3 heteroalkylene group comprises one or more heteroatoms selected from oxygen, nitrogen, phosphorus, and sulfur, the total number of heteroatoms in each ring including D The number is two or less, the composition for semiconductor photoresists. The composition of claim 5, wherein R is a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C12 cycloalkyl group, or a substituted or unsubstituted C6 to C12 aryl group. In claim 5, A, B, and C are each independently hydrogen, a substituted or unsubstituted C1 to C9 alkyl group, a substituted or unsubstituted C3 to C9 cycloalkyl group, or a substituted or unsubstituted C6 to C9 aryl A composition for semiconductor photoresists. The composition of claim 1, wherein the composition further comprises an additive of a surfactant, a crosslinking agent, a leveling agent, or a combination thereof. forming an etch target layer on the substrate;
forming a photoresist layer by applying the composition for a semiconductor photoresist according to any one of claims 1 to 9 on the etching target layer;
forming a photoresist pattern by patterning the photoresist layer; and
and etching the etch target layer using the photoresist pattern as an etch mask. The method of claim 10 , wherein the forming of the photoresist pattern uses light having a wavelength of 5 nm to 150 nm.

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