When the ligands of X, Y, and Z are —SR^bor —SC(═O)R^d, the organometallic compound includes a Sn—S bond, and the bond between Sn—S has a relatively low bond strength. Since the organometallic compound of the present invention including the Sn—S bond may have improved water stability, and the storage stability and solubility of the semiconductor photoresist composition including the same may be improved. In addition, the Sn—S bond may exhibit excellent sensitivity as the bond dissociation energy to extreme ultraviolet exposure is relatively low. The ligands of X, Y, and Z are —OR^aor —OC(═O)R^c, and when the organometallic compound includes —OR^aor —OC(═O)R^cas a ligand, a pattern formed using a semiconductor photoresist composition including the same may exhibit excellent limit resolution.

Therefore, when —OR^a, —SR^b, —OC(═O)R^c, or —SC(═O)R^dis mixed and used as a ligand of an organometallic compound, a semiconductor photoresist composition may have excellent storage stability and solubility while also excellent sensitivity and resolution.

In addition, X, Y, and Z of Chemical Formula 1 that is —OR^a, —SR^b, —OC(═O)R^c, or —SC(═O)R^dmay determine the solubility of the compound in a solvent.

R may be, for example, a substituted or unsubstituted C1 to C8 alkyl group, a substituted or unsubstituted C3 to C8 cycloalkyl group, a substituted or unsubstituted C2 to C8 aliphatic unsaturated organic group including at least one double bond or triple bond, a substituted or unsubstituted C6 to C20 aryl group, an ethoxy group, a propoxy group, —C(═O)R¹(wherein, R¹is hydrogen or a substituted or unsubstituted C1 to C8 alkyl group), or a combination thereof, for example, a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, a tert-butyl group, a 2,2-dimethylpropyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, an ethenyl group, a propenyl group, a butenyl group, an ethynyl group, a propynyl group, a butynyl group, a phenyl group, a tolyl group, a xylene group, a benzyl group, an ethoxy group, a propoxy group, a formyl group, an acetyl group, a propanoyl group, a butanoyl group, or a combination thereof.

R^aand R^bmay be for example independently a substituted or unsubstituted C1 to C8 alkyl group, a substituted or unsubstituted C3 to C8 cycloalkyl group, a substituted or unsubstituted C2 to C8 alkenyl group, a substituted or unsubstituted C2 to C8 alkynyl group, a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof, for example, methyl group, ethyl group, propyl group, butyl group, isopropyl group, tert-butyl group, 2,2-dimethylpropyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, ethenyl group, a propenyl group, a butenyl group, an ethynyl group, a propynyl group, a butynyl group, a phenyl group, a tolyl group, a xylene group, a benzyl group, or a combination thereof.

R^cand R^dmay be, for example, each independently hydrogen, a substituted or unsubstituted C1 to C8 alkyl group, a substituted or unsubstituted C3 to C8 cycloalkyl group, a substituted or unsubstituted C2 to C8 alkenyl group, a substituted or unsubstituted C2 to C8 alkynyl group, a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof, for example, hydrogen, methyl group, ethyl group, propyl group, butyl group, isopropyl group, tert-butyl group, 2,2-dimethylpropyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, ethenyl group, a propenyl group, a butenyl group, an ethynyl group, a propynyl group, a butynyl group, a phenyl group, a tolyl group, a xylene group, a benzyl group, or a combination thereof.

The organometallic compound may include one of compounds represented by Chemical Formula a to Chemical Formula t or a combination thereof.

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In Chemical Formula a to Chemical Formula t, definitions for R^ato R^dare the same as described above.

Referring to the compounds represented by Chemical Formula a to Chemical Formula t, the organometallic compound according to an embodiment may include —OR^a, —SR^b, —OC(═O)R^c, or —SC(═O)R^din various combinations as X, Y, and Z ligands.

A generally-used organic resist has insufficient etch resistance and thus a pattern having a high aspect ratio may collapse.

On the other hand, a conventional inorganic resist (e.g., a metal oxide compound) uses a mixture of sulfuric acid having high corrosiveness and hydrogen peroxide and thus is difficult to handle and has insufficient storage-stability, is a little relatively difficult to structurally change for performance improvement as a composite mixture, and should use a developing solution having a high concentration.

On the contrary, the semiconductor resist composition according to an embodiment may have relatively improved etch resistance, sensitivity, and resolution, and may be handled more easily compared with a conventional organic and/or inorganic resists as the organometallic compound includes a structural unit where various organic groups are bonded with the central metal atom as described above.

In the semiconductor photoresist composition according to an embodiment, the organometallic compound represented by Chemical Formula 1 may be included in an amount of 1 wt % to 30 wt %, for example, 1 wt % to 25 wt %, for example, 1 wt % to 20 wt %, for example, 1 wt % to 15 wt %, for example, 1 wt % to 10 wt %, for example, 1 wt % to 5 wt % based on the total weight of the composition, but is not limited thereto. When the organometallic compound represented by Chemical Formula 1 is included in an amount within the above range, storage stability and solubility characteristics of the composition for semiconductor photoresists are improved, thin film formation is facilitated, and resolution characteristics are improved.

The solvent of the semiconductor resist composition according to the embodiment may be an organic solvent, and may be for example aromatic compounds (e.g., xylene, toluene, etc.), alcohols (e.g., 4-methyl-2-pentenol, 4-methyl-2-propanol, 1-butanol, methanol, isopropyl alcohol, 1-propanol), ethers (e.g., anisole, tetrahydrofuran), esters (n-butyl acetate, propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate), ketones (e.g., methyl ethyl ketone, 2-heptanone), or a mixture thereof, but is not limited thereto.

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 of Group 1.

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

The resin may be included in an amount of 0.1 wt % to 50 wt % based on the total amount of the semiconductor resist composition.

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

On the other hand, the semiconductor resist composition according to an embodiment may consist of the organometallic compound, the solvent, and the resin. However, the semiconductor resist composition according to the embodiment may further include additives as needed. Examples of the additives may be a surfactant, a cross-linking agent, a leveling agent, an organic acid, a quencher, or a combination thereof.

The surfactant may include for example an alkyl benzene sulfonate salt, an alkyl pyridinium salt, polyethylene glycol, a quaternary ammonium salt, or a combination thereof, but is not limited thereto.

The cross-linking agent may be for example a melamine-based cross-linking agent, a substituted urea-based cross-linking agent, an acryl-based cross-linking agent, an epoxy-based cross-linking agent, or a polymer-based cross-linking agent, but is not limited thereto. It may be a cross-linking agent having at least two cross-linking forming substituents, for example, a compound such as methoxymethylated glycoluril, butoxymethylated glycoluril, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, 4-hydroxybutyl acrylate, acrylic acid, urethane acrylate, acryl methacrylate, 1,4-butanediol diglycidyl ether, glycidol, diglycidyl 1,2-cyclohexane dicarboxylate, trimethylpropane triglycidyl ether, 1,3-bis(glycidoxypropyl)tetramethyldisiloxane, methoxymethylated urea, butoxymethylated urea, or methoxymethylated thiourea, and the like.

The leveling agent may be used for improving coating flatness during printing and may be a commercially available known leveling agent.

The organic acid may be p-toluenesulfonic acid, benzenesulfonic acid, p-dodecylbenzene sulfonic acid, 1,4-naphthalene disulfonic acid, methane sulfonic acid, a luorinated sulfonium salt, malonic acid, citric acid, propionic acid, methacrylic acid, oxalic acid, lactic acid, glycolic acid, succinic acid, or a combination thereof, but is not limited thereto.

The quencher may be diphenyl(p-tryl) amine, methyl diphenyl amine, triphenyl amine, phenylenediamine, naphthylamine, diaminonaphthalene, or a combination thereof.

A use amount of the additives may be controlled depending on desired properties.

In addition, the semiconductor photoresist composition may further include a silane coupling agent as an adherence enhancer in order to improve a close-contacting force with the substrate (e.g., in order to improve adherence of the semiconductor photoresist composition to the substrate). The silane coupling agent may be for example a silane compound including a carbon-carbon unsaturated bond such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyl trichlorosilane, vinyltris(β-methoxyethoxy)silane; or 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, p-styryl trimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyl diethoxysilane; trimethoxy[3-(phenylamino)propyl]silane, and the like, but is not limited thereto.

The semiconductor photoresist composition may be formed into a pattern having a high aspect ratio without a collapse. Accordingly, in order to form a fine pattern having a width of, for example, 5 nm to 100 nm, for example, 5 nm to 80 nm, for example, 5 nm to 70 nm, for example, 5 nm to 50 nm, for example, 5 nm to 40 nm, for example, 5 nm to 30 nm, or for example, 5 nm to 20 nm, the semiconductor photoresist composition may be used for a photoresist process using light in a wavelength ranging from 5 nm to 150 nm, for example, 5 nm to 100 nm, 5 nm to 80 nm, 5 nm to 50 nm, 5 nm to 30 nm, or 5 nm to 20 nm. Accordingly, the semiconductor photoresist composition according to an embodiment may be used to realize extreme ultraviolet lithography using an EUV light source of a wavelength of 13.5 nm.

According to according to another embodiment, a method of forming patterns using the aforementioned semiconductor photoresist composition is provided. For example, the manufactured pattern may be a photoresist pattern.

The method of forming patterns according to an embodiment includes forming an etching-objective layer on a substrate, coating the semiconductor photoresist composition on the etching-objective layer to form a photoresist layer, patterning the photoresist layer to form a photoresist pattern, and etching the etching-objective layer using the photoresist pattern as an etching mask.

Hereinafter, a method of forming patterns using the semiconductor photoresist composition is described referring to FIGS. 1 to 5. FIGS. 1 to 5 are cross-sectional views for explaining a method of forming patterns using a semiconductor photoresist composition according to an embodiment.

Referring to FIG. 1, an object for etching is prepared. The object for etching may be a thin film 102 formed on a semiconductor substrate 100. Hereinafter, the object for etching is limited to the thin film 102. A whole surface of the thin film 102 is washed to remove impurities and the like remaining thereon. The thin film 102 may be for example a silicon nitride layer, a polysilicon layer, or a silicon oxide layer.

Subsequently, the resist underlayer composition for forming a resist underlayer 104 is spin-coated on the surface of the washed thin film 102. However, the embodiment is not limited thereto, and known various coating methods, for example a spray coating, a dip coating, a knife edge coating, a printing method, for example an inkjet printing and a screen printing, and the like may be used.

The coating process of the resist underlayer may be omitted, and hereinafter, a process including a coating of the resist underlayer is described.

Then, the coated composition is dried and baked to form a resist underlayer 104 on the thin film 102. The baking may be performed at 100° C. to 500° C., for example, 100° C. to 300° C.

The resist underlayer 104 is formed between the substrate 100 and a photoresist layer 106 and thus may prevent non-uniformity and pattern-forming capability of a photoresist line width when a ray reflected from on the interface between the substrate 100 and the photoresist layer 106 or a hardmask between layers is scattered into an unintended photoresist region.

Referring to FIG. 2, the photoresist layer 106 is formed by coating the semiconductor photoresist composition on the resist underlayer 104. The photoresist layer 106 is obtained by coating the aforementioned semiconductor photoresist composition on the thin film 102 formed on the substrate 100 and then, curing it through a heat treatment.

More specifically, the formation of a pattern by using the semiconductor photoresist composition may include coating the semiconductor photoresist composition on the substrate 100 having the thin film 102 through spin coating, slit coating, inkjet printing, and the like and then, drying it to form the photoresist layer 106.

The semiconductor photoresist composition has already been illustrated in detail and will not be illustrated again.

Subsequently, a substrate 100 having the photoresist layer 106 is subjected to a first baking process. The first baking process may be performed at about 80° C. to about 120° C.

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

For example, the exposure may use an activation radiation with light having a high energy wavelength such as EUV (extreme ultraviolet; a wavelength of 13.5 nm), an E-Beam (an electron beam), and the like as well as a short wavelength such as an i-line (a wavelength of 365 nm), a KrF excimer laser (a wavelength of 248 nm), an ArF excimer laser (a wavelength of 193 nm), and the like.

More specifically, light for the exposure according to an embodiment may have a short wavelength ranging from 5 nm to 150 nm and a high energy wavelength, for example, EUV (extreme ultraviolet; a wavelength of 13.5 nm), an E-Beam (an electron beam), and the like.

The exposed region 106a of the photoresist layer 106 has a different solubility from the non-exposed region 106b of the photoresist layer 106 by forming a polymer by a cross-linking reaction such as condensation between organometallic compounds.

Subsequently, the substrate 100 is subjected to a second baking process. The second baking process may be performed at a temperature of 90° C. to 200° C. The exposed region 106a of the photoresist layer 106 becomes easily indissoluble regarding a developing solution due to the second baking process.

In FIG. 4, the non-exposed region 106b of the photoresist layer is dissolved and removed using the developing solution to form a photoresist pattern 108. Specifically, the non-exposed region 106b of the photoresist layer is dissolved and removed by using an organic solvent such as 2-heptanone and the like to complete the photoresist pattern 108 corresponding to the negative tone image.

As described above, a developing solution used in a method of forming patterns according to an embodiment may be an organic solvent. The organic solvent used in the method of forming patterns according to an embodiment may be for example ketones such as methylethylketone, acetone, cyclohexanone, 2-heptanone, and the like, alcohols such as 4-methyl-2-propanol, 1-butanol, isopropanol, 1-propanol, methanol, and the like, esters such as propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate, n-butyl acetate, butyrolactone, and the like, aromatic compounds such as benzene, xylene, toluene, and the like, or a combination thereof.

However, the photoresist pattern according to an embodiment is not necessarily limited to the negative tone image but may be formed to have a positive tone image. Herein, a developing agent used for forming the positive tone image may be a quaternary ammonium hydroxide composition such as tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, or a combination thereof.

As described above, exposure to light having a high energy such as EUV (extreme ultraViolet; a wavelength of 13.5 nm), an E-Beam (an electron beam), and the like as well as light having a wavelength such as i-line (wavelength of 365 nm), KrF excimer laser (wavelength of 248 nm), ArF excimer laser (wavelength of 193 nm), and the like may provide a photoresist pattern 108 having a width of a thickness of 5 nm to 100 nm. For example, the photoresist pattern 108 may have a width of a thickness of 5 nm to 90 nm, 5 nm to 80 nm, 5 nm to 70 nm, 5 nm to 60 nm, 5 nm to 50 nm, 5 nm to 40 nm, 5 nm to 30 nm, or 5 nm to 20 nm.

On the other hand, the photoresist pattern 108 may have a pitch of having a half-pitch of less than or equal to about 50 nm, for example less than or equal to about 40 nm, for example less than or equal to about 30 nm, for example less than or equal to about 20 nm, for example less than or equal to about 15 nm, and a line width roughness of less than or equal to about 10 nm, less than or equal to about 5 nm, less than or equal to about 3 nm, or less than or equal to about 2 nm.

Subsequently, the photoresist pattern 108 is used as an etching mask to etch the resist underlayer 104. Through this etching process, an organic layer pattern 112 is formed. The organic layer pattern 112 also may have a width corresponding to that of the photoresist pattern 108.

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

The etching of the thin film 102 may be for example dry etching using an etching gas and the etching gas may be for example CHF3, CF4, CI2, BCI3 and a mixed gas thereof.

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

Mode for Invention

Hereinafter, the present invention will be described in more detail through examples of the preparation of the aforementioned semiconductor photoresist composition. However, the present invention is technically not restricted by the following examples.

EXAMPLES
Synthesis Example 1: Synthesis of Intermediate A

Ph₄Sn (20 g, 46.8 mmol) was put in a 250 mL 2-necked round-bottomed flask, 60 mL of propionic acid was added thereto and then, heated under reflux for 24 hours, and the non-reacted propionic acid was removed therefrom under a reduced pressure, obtaining a compound represented by Intermediate A at a yield of 85%.

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Synthesis Example 2: Synthesis of Intermediate B

Ph₄Sn (20 g, 46.8 mmol) was put in a 250 mL 2-necked round-bottomed flask, 60 mL of acetic acid was added thereto and then, heated under reflux for 24 hours, and the non-reacted acetic acid was removed therefrom under a reduced pressure, obtaining a compound represented by Intermediate B at a yield of 90%.