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In some embodiments, R_bof the second repeating unit does not include an aromatic hydrocarbon group (i.e., is devoid of an aromatic hydrocarbon group). For example, R_bof the second repeating unit may be a single bond or a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms. In this case, the photoresist composition for EUV including the additive may exhibit improved surface hydrophilicity.

In some embodiments, the second repeating unit is present in the copolymer at a concentration of about 1 mol % to about 40 mol %. As such, in some embodiments, in the copolymer, the molar ratio of the first repeating unit to the second repeating unit may be from about 99:1 to about 60:40. When the concentration of the second repeating unit is less than about 1 mol % in the copolymer, the additive may not have sufficient surface hydrophilicity for a precision development process. When the concentration of the second repeating unit exceeds about 40 mol % in the copolymer, the additive may not suitably self-segregate to the surface of the photoresist film. Preferably, in the copolymer, the concentration of the second repeating unit is from about 5 mol % to about 20 mol %. As such, in some embodiments, in the copolymer, the molar ratio of the first repeating unit to the second repeating unit is from about 95:5 to about 80:20.

In some embodiments, the copolymer may further include one or more additional repeating unit(s) in addition to the first repeating unit and the second repeating unit. For example, the one or more additional repeating unit(s) may include, but are not limited to, at least one of a repeating unit that includes a lactone, a repeating unit that includes an ester, and a repeating unit that includes a fluorinated hydrocarbon.

The copolymer may be, but is not limited to, a block copolymer or a random copolymer. Preferably, the copolymer is a block copolymer.

The weight average molecular weight (Mw) of the copolymer may be adjusted appropriately in consideration of the desired resolution of the pattern formed using the photoresist, the viscosity of the photoresist, the solvent used in the developing process for the photoresist, the presence or absence of defects, and the like. As an example, in some embodiments, the weight average molecular weight of the copolymer is about 500 g/mol to about 500,000 g/mol. Preferably, the weight average molecular weight of the copolymer is about 5,000 g/mol to about 50,000 g/mol. When the weight average molecular weight of the copolymer exceeds about 50,000 g/mol, the defects in the photoresist pattern may be deepened during the developing process. More preferably, the weight average molecular weight of the copolymer is about 5,000 g/mol to about 30,000 g/mol. In some embodiments, the dispersity of the molecular weight of the copolymer may be, for example, about 1.5 or less.

The concentration of the additive in the photoresist composition may be appropriately adjusted in consideration of the quality of the pattern and the like. For example, the concentration of the additive, based on the total weight of the photoresist composition, may be from about 0.001% by weight to about 5% by weight. Preferably, the concentration of the additive in the photoresist composition is about 0.01% by weight to about 1% by weight, based on the total weight of the photoresist composition.

Alternatively, in some embodiments, the concentration of the additive in the photoresist composition is about 0.01% by weight to about 50% by weight, based on the total weight of the photosensitive resin. Within this range, the additive may sufficiently increase the dissolution rate of the photoresist in an aqueous alkaline developer. This may make it possible to prevent or decrease pattern defects that may occur due to incomplete removal or reattachment of the photoresist in the developing process. Preferably, the concentration of the additive in the photoresist composition, relative to the total weight of the photosensitive resin, is about 0.1% by weight to about 20% by weight. More preferably, the concentration of the additive, relative to the total weight of the photosensitive resin, is about 1% by weight to about 10% by weight.

The photoresist composition for EUV according to some embodiments may further include a photo-decomposable quencher (PDQ) (hereinafter, “quencher”).

The quencher may improve the uniformity and planarity of the photoresist film after the post-exposure baking process. The quencher may include, for example, but is not limited to, at least one of hydrogen chloride, an ether, an ester, an alcohol, water, a fluorine compound, a cyanide, a ketone, a bromide, an iodide, an amine, an aldehyde, a phenol, a nitro compounds, or any combination thereof. As a particular example, the quencher may include triphenylsulfonium benzoate.

The amount of the quencher may be appropriately adjusted in consideration of the quality of the pattern and the like. As an example, the concentration of the quencher in the photoresist composition may be about 0.1% by weight to about 50% by weight, based on the total weight of the photosensitive resin. Preferably, the concentration of the quencher is about 1% by weight to about 40% by weight, based on the total weight of the photosensitive resin. More preferably, the concentration of the quencher is about 10% by weight to about 30% by weight, based on the total weight of the photosensitive resin.

The photoresist composition for EUV according to some embodiments may further include an organic solvent.

In some embodiments, the organic solvent may be included as the remainder of the photoresist composition for EUV. The organic solvent may dissolve the photosensitive resin or the like. As an example, the organic solvent may include, but is not limited to, at least one of a ketone such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone and 2-heptanone; a polyhydric alcohol and/or a derivative thereof such as ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, dipropylene glycol, monomethyl ether of dipropylene glycol monoacetate, monoethyl ether, monopropyl ether, and monophenyl ether; a cyclic ether such as dioxane; an ester such as ethyl formate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl pyruvate, ethyl ethoxyacetate, methyl methoxypropionate, ethyl ethoxypropionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, and 3-methyl-3-methoxybutyl acetate; and an aromatic hydrocarbon such as toluene and xylene. Combinations of any of the foregoing organic solvents may also be used.

Methods for Manufacturing Semiconductor Devices

Hereinafter, methods for manufacturing a semiconductor device using a photoresist composition of the invention will be described with reference to FIGS. 1 to 6. However, these are merely examples and the present disclosure is not limited to these embodiments.

FIGS. 1 to 6 are diagrams illustrating a method for manufacturing a semiconductor device according to some embodiments.

Referring to FIG. 1, a substrate 10 is provided. Subsequently, a target film 20, a mask film 30, and a photoresist film 40 are sequentially formed on the substrate 10.

In some embodiments, the substrate 10 may be bulk silicon or silicon-on-insulator (SOI). For example, the substrate 10 may be a silicon substrate or may include other materials, for example, silicon germanium, gallium arsenide, silicon germanium on insulator (SGOI), indium antimonide, lead tellurium compounds, indium arsenide, indium phosphide, gallium arsenide or gallium antimonide. In other embodiments, the substrate 10 may have an epitaxial layer formed on the base substrate, or may be a ceramic substrate, a quartz substrate, a glass substrate for a display, or the like.

The target film 20 may be formed on the substrate 10. The target film 20 may be a layer in which an image is transferred from a photoresist pattern (e.g., 45 of FIG. 4) to be described below, and converted into a predetermined target pattern (e.g., 25 of FIGS. 5 and 6).

As an example, the target film 20 may include a conductive material such as a metal, a metal nitride, a metal silicide, and/or a metal silicide nitride film. As another example, the target film 20 may include an insulating material such as silicon oxide, silicon nitride, and/or silicon oxynitride. As still another example, the target film 20 may include a semiconductor material such as polysilicon.

The mask film 30 may be formed on the target film 20. The mask film 30 may be formed by, for example, applying it onto the target film 20 using a spin coating process and then performing a baking process. The mask film 30 may include, for example, but is not limited to, a spin-on hard mask (SOH).

The photoresist film 40 may be formed on the mask film 30. The photoresist film 40 may be applied onto the mask film 30 by, for example, an application process such as a spin coating process, a dip coating process, and/or a spray coating process.

The photoresist film 40 may include one or more of the photoresist compositions of the invention. For example, the photoresist film 40 may include a photosensitive resin, a photoacid generator, an additive 40a, and an organic solvent. The additive 40a may be any of the additives for photoresist compositions described herein. For example, the additive 40a may comprise a copolymer including the first repeating unit and the second repeating unit, as described herein.

Referring to FIG. 2, the additive 40a may become self-segregated to the surface of the photoresist film 40.

The additive 40a may have a relatively low surface energy (e.g., about 40 mN/m or less) compared to other constituent components of the photoresist film 40 due to the first repeating unit being fluorinated. Therefore, additive 40a may be substantially distributed on the surface of the photoresist film 40 (for example, the upper surface of the photoresist film 40).

In some embodiments, a first baking process may be performed on the photoresist film 40. The first baking process may include, but is not limited to, a preliminary curing process such as a post-application baking process performed at a temperature in a range of about 50° C. to about 300° C. As the first baking process is performed, the organic solvent in the photoresist film 40 may be volatilized, and the adhesion between the mask film 30 and the photoresist film 40 may be enhanced. Further, as the first baking process is performed, the additive 40a may more easily self-segregate to the surface of the photoresist film 40.

Referring to FIG. 3, an exposure process may then be performed on the photoresist film 40.

The photoresist film 40 may be divided into an exposed part 42 and a non-exposed part 44 by the exposure process. For example, an exposure mask 50 may be placed on the photoresist film 40. When radiation (e.g., a EUV beam) is directed from a radiation source through the upper part of the exposure mask 50, the radiation that passes through a transmission portion (e.g., hole or absent portion) of the exposure mask 50 may irradiate a portion of the photoresist film 40 to form the exposed part 42. The other portion of the photoresist film 40 that is not irradiated with radiation due to shielding from the exposure mask 50 may form the non-exposed part 44.

The radiation (beam) source may be, but is not limited to, a KrF excimer laser beam source, an ArF excimer laser beam source, or an extreme ultraviolet (EUV) source. In some embodiments, the beam source may be an extreme ultraviolet (EUV) source.

In some embodiments, a second baking process may be performed on the photoresist film 40 after the exposure process is performed. The second baking process may include, but is not limited to, a preliminary curing process such as a post-exposure baking process performed at a temperature in a range of about 50° C. to about 300° C. As the second baking process is performed, the solubility of the exposed part 42 may be increased relative to the solubility of the unexposed part 44. For example, the photosensitive resin of the exposed part 42 may undergo a chain chemical reaction due to the photoacid generated from the photoacid generator.

Referring to FIG. 4, a developing process may then be performed on the photoresist film 40 to form a photoresist pattern 45.

In some embodiments, a positive tone development (PTD) process may be performed. For example, due to the exposure process, the solubility of the exposed part 42 in a developer may be increased relative to the solubility of the non-exposed part 44. As a result, the exposed part 42 may be dissolved in the developer and removed in the developing process. The non-exposed part 44 may remain after the developing process to form the photoresist pattern 45. The developer may include, for example, a hydrophilic developer such as deionized water and an alcohol-based solution. In some embodiments, the developer may include an aqueous alkaline developer such as such as tetramethylammonium hydroxide (TMAH).

In the developing process, the additive 40a may improve the dissolution rate of the exposed part 42 of the photoresist film 40. Specifically, the additive 40a may have a relatively high dissolution rate in a hydrophilic developer due to the second repeating unit being an acrylamide-based repeating unit. In particular, as described above, the second repeating unit of the additive 40a may have higher solubility in an aqueous alkaline developer (e.g., TMAH) due to the sulfonic acid group which is an acidic functional group.

As the design rules of the semiconductor elements are gradually reduced, a lithography process that utilizes extreme ultraviolet (EUV), which has a short wavelength radiation beam, may be utilized. In such an EUV lithography process, since precise development is required to form a fine pattern, control of defects caused by the developing process has become an important issue. For example, existing photoresists have the problem that the dissolution rate of a photoresist portion (e.g., exposed part