Abstract: A positive resist composition for use with an electron beam, an EUV light or an X ray, the positive resist composition comprising: (A) at least one compound that generates an acid upon treatment with one of an actinic ray and radiation; and (B) a resin that increases a solubility of the resin (B) in an alkaline developer by an action of an acid, wherein the resin (B) comprises a repeating unit having an alicyclic group connected with a fluorine-substituted alcohol residue; and a pattern formation method using the composition.

Abstract: A photopolymerization initiator composition containing a thiol compound having a mercapto group-containing group that has at least one substituent on the carbon atoms on carbon atom(s) at the ?- and/or ?-position with respect to the mercapto group and a photopolymerization initiator; a photosensitive composition containing the composition; and a novel thiol compound for use in these compositions. The photosensitive composition containing the photopolymerizazion initiator composition of the present invention has high sensitivity and excellent storage stability and enables reduction in cost due by increasing productivity.

Abstract: A photosensitive composition comprising a compound capable of generating a specific sulfonic acid upon irradiation with actinic rays or a radiation; a compound capable of generating a specific sulfonic acid upon irradiation with an actinic ray or a radiation; and a pattern forming method using a photosensitive composition comprising a compound capable of generating a specific sulfonic acid upon irradiation with an actinic ray or a radiation.

Abstract: A positive resist composition comprising (A) a resin that contains a repeating unit represented by formula (1) defined in the specification and a repeating unit represented by formula (2) defined in the specification, and is insoluble or slightly soluble in an alkali developer and becomes soluble in an alkali developer by an action of an acid, and (B) a compound generating a sulfonic acid compound represented by formula (3) defined in the specification upon irradiation of actinic ray or radiation.

Abstract: A positive tone radiation-sensitive resin composition comprising (A) a 1-substituted imidazole, (B) a photoacid generator, and (C-a) a resin protected by an acid-dissociable group, insoluble or scarcely soluble in alkali, but becoming soluble in alkali when the acid-dissociable group dissociates or (C-b) an alkali-soluble resin and an alkali solubility controller, and a negative tone radiation-sensitive resin composition comprising (A), (B), (D) an alkali-soluble resin, and (E) a compound that can crosslink the alkali-soluble resin in the presence of an acid. The radiation-sensitive resin composition of the present invention is a chemically amplified resist exhibiting high resolution and high storage stability as a composition, and suitable for microfabrication sensible to active radiations, for example, ultraviolet rays such as g-lines and i-lines, deep ultraviolet rays represented by a KrF excimer laser, ArF excimer laser, F2 excimer laser, and EUV excimer laser, and electron beams.

Abstract: An undercoat-forming material comprising a novolak resin having a fluorene or tetrahydrospirobiindene structure, an organic solvent, an acid generator, and a crosslinker, optionally combined with an intermediate layer having an antireflective effect, has an absorptivity coefficient sufficient to provide an antireflective effect at a thickness of at least 200 nm and a high etching resistance as demonstrated by slow etching rates with CF4/CHF3 and Cl2. BCl3 gases for substrate processing.

Abstract: The photobase generator of the invention is represented by the following formula 1: wherein Ar, R, A+ and X? are as defined in the specification. Since the photobase generator of the formula 1 absorbs ultraviolet lights of relatively long wavelength and is photolyzed to generate a strong base efficiently, a composition containing the photobase generator and an episulfide compound is easily cured by polymerization under ultraviolet irradiation.

Abstract: A polymerizable composition contains (A) a dye which is soluble in an organic solvent and in an alkaline aqueous solution and has an absorption in 700 to 1200 nm, (B) a radical polymerization initiator, (C) a compound having an ethylenically unsaturated bond, and (D) a binder polymer.

Abstract: A radiation-sensitive resin composition comprising (A) an acid-dissociable group-containing polysiloxane and (B) a photoacid generator containing trifluoromethane sulfonic acid or a compound which generates an acid of the following formula (I), wherein Rf individually represents a fluorine atom or a trifluoromethyl group, and Ra represents a hydrogen atom, a fluorine atom, a linear or branched alkyl group having 1-20 carbon atoms, or a linear or branched fluoroalkyl group having 1-20 carbon atoms, a substituted or unsubstituted monovalent cyclic hydrocarbon group having 3-20 carbon atoms, or a substituted or unsubstituted monovalent cyclic fluoro-hydrocarbon group having 3-20 carbon atoms. The radiation-sensitive resin composition of the present invention exhibits superior resolution, while maintaining high transparency to radiations and high dry etching resistance. The resin composition thus can greatly contribute to the lithography process that will become more and more minute in the future.

Abstract: A positive resist composition comprising (A) a resin that increases solubility in an alkali developing solution by the action of an acid and (B-1) a compound having a structure represented by formula (I) defined in the specification.

Abstract: A photoresist composition for preventing exposing failures and a method of forming a pattern using the same are disclosed. The photoresist composition preferably comprises about 0.1% to about 0.5% by weight of a photo acid generator, and about 2% to about 10% by weight of a polymer resin, the PAG including a monophenyl sulfonium compound, a triphenyl sulfonium compound or a mixture thereof. The footing phenomenon and the top loss of a pattern are sufficiently prevented.

Abstract: A photosensitive composition comprising: (A) a polymerizable compound represented by the following formula (I): A—{O—[(CH(—R1)CH(—R2))m—O]n—C(?O)—C(—R3)?CH2}p??(I) wherein R1, R2and R3 each represents a hydrogen atom or a methyl group, A represents a polyhydric alcohol residue or a polyhydric phenol residue, m represents an integer of from 1 to 6, n represents an integer of from 1 to 20, and p represents an integer of from 1 to 6; (B) an infrared absorber; and (C) an onium salt.

Abstract: A negative resist composition and a method for patterning semiconductor devices using the composition are provided. The negative resist composition contains an alkali-soluble hydroxy-substituted base polymer, a silicon-containing crosslinker having an epoxy ring, and a photoacid generator. In the method for patterning semiconductor devices, fine patterns are formed according to a bi-layer resist process using the negative resist composition.

Abstract: The present invention relates to a novel antireflective coating composition comprising a polymer, a crosslinking agent and an acid generator. The present invention further relates to a process for using the novel composition, particularly at 193 nm. The polymer of the present invention contains at least one unit selected from structures 1, 2 and 3, where, Y is a hydrocarbyl linking group of 1 to about 10 carbon atoms, R, R1, R? and R? are independently hydrogen, hydrocarbyl group of 1 to about 10 carbon atoms, halogen, —O(CO)Z, —C(CF3)2Z, —C(CF3)2(CO)OZ, —SO2CF3, —(CO)OZ, —SO3Z, —COZ, —OZ, —NZ2, —SZ, —SO2Z, —NHCOZ, —NZCOZ or —SO2NZ2, where Z is H or a hydrocarbyl group of 1 to about 10 carbon atoms, n=1–4, X is O, CO, S, COO, CH2O, CH2COO, SO2, NH, NL, OWO, OW, W, and where L and W are independently hydrocarbyl groups of 1 to about 10 carbon atoms, and m=0–3.

Abstract: A positive resist composition having excellent mask linearity is provided. This composition is a positive resist composition comprising a base resin component (A) and an acid generator component (B) generating an acid under exposure, wherein the base resin component (A) is a silicone resin and the acid generator component (B) contains an onium salt-based acid generator (B1) containing a perfluoroalkyl sulfonate ion having 3 or 4 carbon atoms as an anion.

Abstract: The present invention provides for a light-sensitive photoresist composition useful for imaging thick films, comprising a polymer which is insoluble in an aqueous alkali developer but becomes soluble prior to development, a photoacid generator which produces a strong acid upon irradiation and a photobleachable dye. The invention further provides for a process for imaging the photoresist of the present invention, especially where the thickness of the photoresist is up to 200 microns and where the process comprises a single exposure step.

Abstract: Photoacid generators have formula (1) wherein R1 and R2 are alkyl, or R1 and R2, taken together, may form a C4–C6 ring structure with sulfur, R is hydrogen or alkyl, R? is hydrogen, alkyl, alkoxyl or nitro, n is 1 to 6, and Y? is alkylsulfonate, arylsulfonate, bisalkylsulfonylimide or trisalkylsulfonylmethide.

Abstract: A composition including a first moiety; and a different second moiety capable of harvesting energy from an external source, wherein the second moiety is positioned such that energy harvested at the second moiety may be transferred to the first moiety. An article of manufacture including a film including a first moiety and a different second moiety capable of harvesting energy from an external source, wherein the second moiety is positioned such that collectively the first and second moieties have an electron capture cross-section greater than the electron capture cross-section of the first moiety alone. A method including forming a film on a substrate including a first moiety and a different second moiety; exposing the film to photonic or charged particle radiation; and patterning the film.

Abstract: The present invention relates to a resin composition comprising: an alkali-soluble resin (A); an infrared absorbing agent (B); and a thiol compound (C), wherein a solubility thereof in an alkaline aqueous solution is changed by exposure with a infrared laser ray, and a positive or negative-type image recording layer containing the resin composition.

Abstract: Compositions and methods of use thereof are disclosed. One exemplary composition, among others, includes a polymer resin and a photoacid generator. In particular, the composition includes a polymer resin, wherein the polymer resin does not substantially absorb about 1 to 450 nanometer (nm) wavelength energy; and a photoacid generator, wherein the photoacid generator does substantially absorb about 1 to 450 nanometer (nm) wavelength energy.

Abstract: The present invention provides a photosensitive resin composition for laser scanning exposure, which satisfies the following formula (1): - 25 ? E 1 - E 0 E 0 × 100 ? 25 ( 1 ) wherein E0 represents an exposure amount in mJ/cm2 at which the photosensitive resin composition is cured at the 21st step of the density 1.00 of a 41-step step tablet having a density range from 0.00 to 2.00, a density step of 0.05, a tablet size of 20 mm×187 mm and a step size of 3 mm×12 mm, by irradiation with a full wavelength active light of a high pressure mercury lamp and E1 represents an exposure amount in mJ/cm2 at which the photosensitive resin composition after being left for 2 hours under 40 W non-ultraviolet white lamp is cured at the 21st step of the 41-step step tablet by irradiation with a full wavelength active light from a high pressure mercury lamp.

Abstract: The present invention provides a chemical amplification type positive resist composition comprising a nitrogen containing compound of the formula (VIa) or (VIb); resin which contains a structural unit having an acid labile group and which itself is insoluble or poorly soluble in an alkali aqueous solution but becomes soluble in an alkali aqueous solution by the action of an acid; and an acid generator of the formula (I)

Abstract: A photoresist composition including a polymer is disclosed, wherein the polymer includes at least one monomer having the formula: where R1 represents hydrogen (H), a linear, branched or cyclo alkyl group of 1 to 20 carbons, a semi- or perfluorinated linear, branched or cyclo alkyl group of 1 to 20 carbons or CN; R2 represents an alicyclic group of 5 or more carbon atoms; X represents a methylene, ether, ester, amide or carbonate linkage; R3 represents a linear or branched alkylene group or semi- or perfluorinated linear or branched alkylene group with 1 or more carbon atoms; R4 represents hydrogen (H), methyl (CH3), trifluoromethyl (CF3), difluoromethyl (CHF2), fluoromethyl (CH2F), or a semi- or perflourinated aliphatic group; R5 represents trifluoromethyl (CF3), difluoromethyl (CHF2), fluoromethyl (CH2F), or a semi- or perfluorinated substituted or unsubstituted aliphatic group; n represents an integer of 1 or more; and OR12 represents OH or at least one acid labile group selected from a tertiary alkyl c

Abstract: An onium salt compound having a cation moiety of the following formula (1) is disclosed. wherein A represents I or S, m is 1 or 2, n is 0 or 1, x is 1–10, and Ar1 and Ar2 are (substituted) aromatic hydrocarbon group, and P represents —O—SO2R, —O—S(O)R, or —SO2R, wherein R represents a hydrogen atom, a (substituted) alkyl group, or a (substituted) alicyclic hydrocarbon group. The onium salt compound is suitable as a photoacid generator for photoresists of a positive-tone radiation-sensitive resin composition. The positive-tone radiation-sensitive resin composition containing this compound is useful as a chemically-amplified photoresist exhibiting high resolution at high sensitivity, responsive to various radiations, and having outstanding storage stability.

Abstract: A positive photosensitive composition comprising (A1) a compound that generates an aromatic sulfonic acid substituted with at least one fluorine atom and/or a group having at least one fluorine atom upon irradiation of an actinic ray or radiation, (B) a resin that has a monocyclic or polycyclic alicyclic hydrocarbon structure and is decomposed by the action of an acid to increase solubility in an alkali developing solution, and (C) a compound that has at least three hydroxy or substituted hydroxy groups and at least one cyclic structure or (A2) an onium salt of an alkanesulfonic acid in which the ?-position of the sulfonic acid is not substituted with a fluorine atom and/or an onium salt of a carboxylic acid.

Abstract: The present invention discloses a cross-linking monomer represented by the following Chemical Formula 1, a process for preparing a photoresist polymer using the same, and said photoresist polymer: <Chemical Formula> wherein, R? and R? individually represent hydrogen or methyl; m represents a number of 1 to 10; and R is selected from the group consisting of straight or branched C1-10 alkyl, straight or branched C1-10 ester, straight or branched C1-10 ketone, straight or branched C1-10 carboxylic acid, straight or branched C1-10 acetal, straight or branched C1-10 alkyl including at least one hydroxyl group, straight or branched C1-10 ester including at least one hydroxyl group, straight or branched C1-10 ketone including at least one hydroxyl group, straight or branched C1-10 carboxylic acid including at least one hydroxyl group, and straight or branched C1-10 acetal including at least one hydroxyl group.

Abstract: The present invention provides a chemical amplification type positive resist composition comprising (A) a resin which comprises (i) 5 to 50% by mol of a structural unit of the formula (I), (ii) 5 to 50% by mol of a structural unit of the formula (II) and (iii) 5 to 50% by mol of at least one selected from the group consisting of structural units of the formulas (III) and (IV), and (B) an acid generator. The present composition is suitable for excimer laser lithography using ArF, KrF and the like, and shows various outstanding resist abilities, specifically, gives better effective sensitivity and resolution to resist patterns obtained therefrom, and gives particularly excellent pattern shape and excellent line edge roughness.

Abstract: A stimulus-sensitive composition comprising a compound (A) that generates one of an acid and a radical by external stimulation, the compound (A) having a specific structure.

Abstract: A chemically amplified radiation-sensitive resin composition comprising a specific copolymer and a photoacid generator, wherein the copolymer contains the following recurring unit (1) and/or the recurring unit (2), and the recurring unit (3-1), wherein R1 is a hydrogen or methyl, R2 is a C4-10 tertiary alkyl, R3 and R4 are a hydrogen, C1-12 alkyl, C6-15 aromatic, C1-12 alkoxyl, or R3 and R4 may form, in combination and together with the nitrogen atom with which the R3 and R4 groups bond, a C3-15 cyclic structure, provided that R3 and R4 are not a hydrogen atom at the same time. The composition effectively responds to various radiations, exhibits excellent resolution and pattern configuration and minimal iso-dense bias, and can form fine patterns at a high precision and in a stable manner.

Abstract: Disclosed is a photosensitive polymer comprising pentafluoromethylvinyl ether derivative monomer having the formula: wherein R may be an alkoxy carbonyl, alkylsilane, a fluorine-substituted or unsubstituted C3–C20 alkyl carbonyl, a fluorine-substituted or unsubstituted C3–C20 cycloalkylcarbonyl or a fluorine-substituted or unsubstituted benzoyl substituent group. The photosensitive polymer is the polymerization product of the pentafluoromethylvinyl ether derivative monomer and at least one additional monomer selected from the group consisting of (meth)acrylic acid, (meth)acrylate, styrene, norbornene, tetrafluoroethylene and maleic anhydride monomers. The photosensitive polymer may be used in photoresist compositions for exposure light sources having a predominant wavelength of less than 157 nm.

Abstract: Carborane based PAG's are bulky, produce a strong and large superacid, and have polarities that are compatible with the chemically amplified polymers typically used in photoresists. Carborane based PAG's also provide another broad class of bulky PAG's that may be used in photoresist formulations that offer flexibility in acid strength and polarity through changes in chemical structure. These PAG's may be used with EUV wavelengths, 157 nm, or 193 nm. Resolution and critical dimension control may be improved through the use of carborane based PAG's.

Abstract: A radical polymerizable composition comprising (A) an alkali-soluble resin containing a radical polymerizable group, (B) a radical polymerizable compound, and (C) a radical initiator, wherein reactivity of a polymerizable group of the polymerizable compound 4B) to a polymerizable group of the polymerizable compound (B) is larger than reactivity of a polymerizable group of the polymerizable compound (B) to a radical polymerizable group of the alkali-soluble resin (A), and a reactivity of a radical polymerizable group of the alkali-soluble resin (A) to a polymerizable group of the polymerizable compound (B) is larger than reactivity of a radical polymerizable group of the alkali-soluble resin (A) to a radical polymerizable group of the alkali-soluble resin (A).

Abstract: A resin which comprises (1) at least one structural unit selected from the group consisting of a structural unit derived from 3-hydroxy-1-adamantyl (meth)acrylate, a structural unit derived from 3,5-dihydroxy-1-adamantyl (meth)acrylate, a structural unit derived from (meth)acryloyloxy-?-butyrolactone having a lactone ring optionally substituted by alkyl, a structural unit of the formula (Ia) and a structural unit of the formula and (2) a structural unit of the formula (II) and which itself is insoluble or poorly soluble in an alkali aqueous solution but becomes soluble in an alkali aqueous solution by the action of an acid; and also provides a chemical amplification type positive resist composition comprising a resin defined above and an acid generator.

Abstract: A positive-working resist composition comprising (A1) a resin containing a repeating unit represented by the specific general formula, wherein the resin increases the solubility in an alkali developing solution by the action of an acid.

Abstract: A photosensitive resin composition of the present invention comprises (A) a resin having a repeating unit represented by formula (IA) and a repeating unit containing an acid decomposable group and copolymerizable with formula (IA), which is decomposed under the action of an acid to increase the solubility in an alkali developer, (B1) a compound capable of generating an aliphatic or aromatic sulfonic acid substituted by at least one fluorine atom upon irradiation with actinic rays or radiation, (B2) a compound capable of generating an aliphatic or aromatic sulfonic acid containing no fluorine atom, or an aliphatic or aromatic carboxylic acid upon irradiation with actinic rays or radiation, and (C) a solvent.

Abstract: The present invention relates to an image forming material having, on a substrate, an image forming layer that includes at least (A) a novolac type phenolic resin containing phenol as a structural unit, (B) a photo-thermal converting agent, and (C) a specific ammonium compound or a specific onium salt.

Abstract: The present invention provides a sulfonium salt of the formula (Ia) a polymeric compound comprising a structural unit of the formula (Ib) and a chemical amplification type positive resist composition comprising (A) an acid generator comprising at least one compound selected from the group consisting of a sulfonium salt of the formula (Ia), a polymeric compound comprising a structural unit of the formula (Ib), and a sulfonium salt of the formula (Ic); and (B) resin which contains a structural unit having an acid labile group and which itself is insoluble or poorly soluble in an alkali aqueous solution but becomes soluble in an alkali aqueous solution by the action of an acid.

Abstract: A soluble polyimide for a photosensitive polyimide precursor and a photosensitive polyimide precursor composition including the soluble polyimide, wherein the soluble polyimide contains hydroxyl and acetyl moieties and at least one reactive end-cap group at one or both ends of the polymer chain. The photosensitive polyimide precursor composition comprises the soluble polyimide, a polyamic acid containing at least one reactive end-cap group at one or both ends of the polymer chain, a photo acid generator (PAG) and optionally a dissolution inhibitor. Since the polyimide film of the present invention exhibits excellent thermal, electric and mechanical properties, it can be used as insulating films or protective films for various electronic devices. A pattern with a high resolution may be formed even on the polyamide film having a thickness of above 10 ?m.

Abstract: Disclosed is a positive-working chemical-amplification photoresist composition used in the patterning works in the manufacture of semiconductor devices, with which quite satisfactory patterning of a photoresist layer can be accomplished even on a substrate surface provided with an undercoating film of silicon nitride, phosphosilicate glass, borosilicate glass and the like in contrast to the prior art using a conventional photoresist composition with which satisfactory patterning can hardly be accomplished on such an undercoating film. The photoresist composition comprises, besides a film-forming resin capable of being imparted with increased solubility in an alkaline solution by interacting with an acid and a radiation-sensitive acid-generating compound, a phosphorus-containing oxo acid such as phosphoric acid and phosphonic acid or an ester thereof.

Abstract: A radiation-sensitive resin composition comprising (A) a resin comprising at least two recurring units of the formulas (1)–(6) in the total amount of 5–70 mol %, but each in the amount of 1–49 mol %, the resin being insoluble or scarcely soluble in alkali, but becoming easily soluble in alkali by the action of an acid, and (B) a photoacid generator. wherein R1 is a hydrogen or methyl and R2 is a substituted or unsubstituted alkyl group having 1–4 carbon atoms. The resin composition is useful as a chemically amplified resist having high transmittance of radiation, sensitivity, resolution, dry etching resistance, and pattern profile.

Abstract: A positive resist composition comprises: (A) a resin capable of decomposing by the action of an acid to increase the solubility in an alkali developer; and (B) a compound capable of generating an acid upon irradiation with one of an actinic ray and a radiation, wherein the resin (A) contains a specified repeating unit.

Abstract: A polymer used for a negative type resist composition having a first repeating unit of a Si-containing monomer unit, a second repeating unit having a hydroxy group or an epoxy ring and copolymerized with the first repeating unit is provided. The first repeating unit is represented by the following formula: wherein R1 is a hydrogen atom or a methyl group, X is a C1–C4 alkyl or alkoxy group, and n is an integer from 2 to 4. Also, there is provided a negative type resist composition including the polymer which is an alkali soluble base polymer, a photoacid generator and a crosslinking agent cross linkable in the presence of an acid.

Abstract: A positive resist composition comprising: (A) a resin having alicyclic hydrocarbon groups in side chains, containing specified two types of repeating units, which increases the solubility in an alkali developing solution by the action of an acid; and (B) a particular sulfonium compound having a specified structure and capable of generating an acid upon irradiation with an actinic ray or radiation.

Abstract: Photoacid generators (PAGs) comprising photoactive moieties and perfluorinated, multifunctional anionic moieties (or incipient anionic moieties) are disclosed which provide photoacids with high acid strength, low volatility and low diffusivity. The present invention further relates to photoacid generators as they are used in photoinitiated or acid-catalyzed processes for uses such as photoresists for microlithography and photopolymerization.

Abstract: In a resist composition comprising a base resin which is a high molecular weight structure free from an aromatic substituent group, a photoacid generator, and a solvent, the photoacid generator is a one capable of generating a perfluoroalkyl ether sulfonic acid. The resist composition has many advantages including excellent resolution, minimized size difference between isolated and densely packed patterns, and minimized line edge roughness.

Abstract: A negative resist composition and a method for patterning semiconductor devices using the composition are provided. The negative resist composition contains an alkali-soluble hydroxy-substituted base polymer, a silicon-containing crosslinker having an epoxy ring, and a photoacid generator. In the method for patterning semiconductor devices, fine patterns are formed according to a bi-layer resist process using the negative resist composition.

Abstract: A stimulus sensitive composition containing a compound capable of generating an acid or a radical on receipt of an external stimulus, the compound being represented by the following formula (I): wherein Y represents a group having a bridged cyclic structure; R1 and R2 each independently represent a hydrogen atom, an alkyl group or an aryl group; R1 and R2 may be taken together to form a ring; Y1 and Y2 each independently represent an alkyl group or an aryl group; Y1 and Y2 may be taken together to form a ring; and X? represents a non-nucleophilic anion.

Abstract: Photoresist polymers and photoresist compositions are disclosed. A photoresist polymer represented by Formula 1 and a photoresist composition containing the same have excellent etching resistance, thermal resistance and adhesive property, and high affinity to an developing solution, thereby improving LER (line edge roughness). wherein X1, X2, R1, R2, m, n, a, b and c are as defined in the description.

Abstract: A negative photoresist composition and a method of patterning a substrate through use of the negative photoresist composition. The composition includes: a radiation sensitive acid generator; a multihydroxy-containing additive; and a resist polymer comprising a first repeating unit from a first monomer. The resist polymer may also comprise a second repeating unit from a second monomer, wherein the second monomer has an aqueous base soluble moiety. The multihydroxy-containing additive has the structure Q-(OH)m, where Q may include at least one alicycic group and m may be any integer between 2 and 6. The acid generator is adapted to generate an acid upon exposure to radiation. The resist polymer is adapted to chemically react with the additive in the presence of the acid to generate a product that is insoluble in a developer solution.

Abstract: Photoresist polymers and photoresist compositions containing the same are disclosed. A negative photoresist composition containing a photoresist polymer comprising a repeating unit represented by Formula 4 prevents collapse of patterns when photoresist patterns of less than 50 nm are formed. Accordingly, the disclosed negative photoresist composition is very effective for a photolithography process using EUV (Extreme Ultraviolet, 13 nm) light source. wherein R1, R2, R3, R4, R5, R6, R7, a, b and c are as defined in the description.