Photosensitive resin and photoresist composition containing same

Abstract

The present invention relates to a photosensitive resin that has high solubility in a developer, good etching resistance, and low line edge roughness even when exposed to a short wavelength light source of less than 248 nm or less than 193 nm. The present invention also relates to a photoresist composition containing the photosensitive resin.

Description

[Technical Field]

[0001] The present invention relates to a photosensitive resin and a photoresist composition containing the same. More specifically, the present invention relates to a photosensitive resin that has high solubility in a developer, good etching resistance, and low line edge roughness even when exposed to short wavelength light sources of less than 248 nm or less than 193 nm, and a photoresist composition containing the photosensitive resin. [Background technology]

[0002] With the increasing integration density of semiconductor integrated circuit devices, gigabit-class dynamic random access memories (DRAMs) with larger storage capacities than the existing 256-megabit DRAMs are being developed. There is also a demand for the development of photosensitive polymer resins and chemically amplified photoresist compositions that can form photoresist patterns with narrower linewidths (e.g., 90 nm) than the linewidths of conventional photoresist patterns (e.g., 0.25 μm).

[0003] Chemically amplified photoresist compositions are typically used in photolithography processes under extreme ultraviolet light sources, such as KrF excimer lasers and ArF excimer lasers, which are short-wavelength exposure sources of less than 250 nm. Such chemically amplified photoresist compositions must satisfy the following requirements: (i) high transparency to the exposure light, (ii) good adhesion to semiconductor circuit substrates, (iii) excellent etching resistance, (iv) no damage such as line edge roughness (LER), top loss, and tilt of the photoresist pattern, and (v) easy development using a common developer such as an aqueous tetramethylammonium hydroxide (TMAH) solution.

[0004] On the other hand, the use of short-wavelength light sources such as extreme ultraviolet light sources (EUVL, 11-13 nm) and F2 (157 nm) allows for the formation of finer patterns, but these light sources have high absorbance, necessitating the use of thinner photoresist films. Immersion lithography is a process that uses ArF (193 nm) as a light source or fills the space between a transmission lens and a wiper with water. This process poses the problem of the reduced adhesion area with the semiconductor substrate due to the miniaturization of the photoresist pattern, leading to the collapse of the resist pattern. One approach to solving this problem is to reduce the thickness of the photoresist film. However, this reduces etching resistance.

[0005] Therefore, bulky compounds are introduced to enhance the etching resistance of thin photoresists. However, photoresist compositions containing bulky compounds have reduced solubility in developers, despite their improved etching resistance, resulting in increased line edge roughness. Etching resistance is the biggest problem with thin photoresists.

[0006] Therefore, there is a need for new types of photoresists that can overcome these drawbacks. Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a photosensitive resin that has high solubility in a developer, good etching resistance, and low line edge roughness even when exposed to a short wavelength exposure light source of less than 248 nm or less than 193 nm, and a photoresist composition containing the photosensitive resin. [Means for solving the problem]

[0008] One aspect of the present invention provides a photosensitive compound having a structure represented by Formula 1 or Formula 2:

[0009] [ka]

[0010] In the formula, x is 0 or 1, y is an integer of 0 to 3, z is an integer of 1 to 10, m is an integer of 1 to 6, and R1, R2, and R3 are each independently C1 to C 10 of hydrocarbons or OC n H 2n+1 (n is an integer of 0 to 10), and R4 is H or CH3;

[0011] [ka]

[0012] In the formula, x is 0 or 1, y is an integer of 0 to 3, z is an integer of 1 to 10, M is C, O, N, or S, and R1, R2, and R3 are each independently C1 to C 10 of hydrocarbons or OC n H 2n+1 (n is an integer of 0 to 10), and R4 is H or CH3.

[0013] In one embodiment, the photosensitive compound may be selected from the group consisting of compounds represented by the following formulas 3 to 34:

[0014] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka]

[0015] A further aspect of the present invention provides a photosensitive resin having a structure represented by Formula 35 or Formula 36:

[0016] [ka]

[0017] In the formula, x is 0 or 1, y is an integer of 0 to 3, z is an integer of 1 to 10, m is an integer of 1 to 6, and R1, R2, and R3 are each independently C1 to C 10 of hydrocarbons or OC n H 2n+1 (n is an integer of 0 to 10), R4 is H or CH3, and a represents the molar fraction of repeating units having the structure represented by formula 35 in all repeating units of the photosensitive resin, and is 0.01 to 100 mol %; [ka]

[0018] In the formula, x is 0 or 1, y is an integer of 0 to 3, z is an integer of 1 to 10, M is C, O, N, or S, and R1, R2, and R3 are each independently C1 to C10 of hydrocarbons or OC n H 2n+1 (n is an integer of 0 to 10), R4 is H or CH3, and a represents the molar fraction of repeating units having the structure represented by formula 36 in all repeating units of the photosensitive resin, and is 0.01 to 100 mol %.

[0019] In one embodiment, the photosensitive resin may include a structure represented by Formula 37 or Formula 38:

[0020] [ka]

[0021] In the formula, each R4 is independently H or a C1-C6 alkyl group, and R1, R2, and R3 are each independently C1-C 10 Hydrocarbons or OC n H 2n+1 (n is an integer from 1 to 10), and R5 is C1 to C 20 or C5-C 40 R6 and R7 are each independently a cycloalkyl group selected from the group consisting of C1 to C 20 Hydroxyalkyl groups, C1-C 10 or a C5-C halogenated hydroxyalkyl group containing an ether or ester moiety. 10 a, b, c, and d represent the molar fractions of the corresponding repeating units in the total photosensitive compounds of the photosensitive polymer resin, and the ratio is 1-70:1-50:1-50:1-50;

[0022] [ka]

[0023] wherein R1, R2, R3, R4, R5, R6, R7, a, b, c, and d are as defined in Formula 37.

[0024] In one embodiment, a may be 1 to 70 mol %.

[0025] In one embodiment, the photosensitive resin may have a weight average molecular weight of 1,000 to 100,000.

[0026] Another aspect of the present invention provides a photoresist composition comprising a photosensitive resin having a structure represented by the following Formula 35 or 36, a photoacid generator, and an organic solvent:

[0027] [ka]

[0028] In the formula, x is 0 or 1, y is an integer of 0 to 3, z is an integer of 1 to 10, m is an integer of 1 to 6, and R1, R2, and R3 are each independently C1 to C 10 of hydrocarbons or OC n H 2n+1 (n is an integer of 0 to 10), R4 is H or CH3, and a represents the molar fraction of repeating units having the structure represented by formula 35 in all repeating units of the photosensitive resin, and is 0.01 to 100 mol %;

[0029] [ka]

[0030] In the formula, x is 0 or 1, y is an integer of 0 to 3, z is an integer of 1 to 10, M is C, O, N, or S, and R1, R2, and R3 are each independently C1 to C 10 of hydrocarbons or OC n H 2n+1 (n is an integer of 0 to 10), R4 is H or CH3, and a represents the molar fraction of repeating units having the structure represented by formula 36 in all repeating units of the photosensitive resin, and is 0.01 to 100 mol %.

[0031] In one embodiment, the photosensitive resin may be present in an amount of 1 to 30 wt %, based on the total weight of the photoresist composition.

[0032] In one embodiment, the photoacid generator may be selected from organic sulfonic acids, sulfide salt compounds, onium salt compounds, and mixtures thereof, and may be present in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the photosensitive resin.

[0033] In one embodiment, the organic solvent may be selected from the group consisting of ethylene glycol monomethyl ethyl, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethoxyethyl acetate, hydroxyethyl acetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxy-2-methylpropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxy-2-methylpropionate, ethyl acetate, butyl acetate, and mixtures thereof. [Effects of the Invention]

[0034] The presence of silicon in the photosensitive resin of the present invention and the introduction of a norbornene moiety, which is a bulky alicyclic hydrocarbon, into the photosensitive resin of the present invention improves etching resistance and heat resistance, and also improves adhesion to a semiconductor substrate.

[0035] The photosensitive resin of the present invention has a structure in which an organic acid group is present in the silicon-containing norbornene moiety, which is a bulky alicyclic hydrocarbon. This structure makes it easy to control the solubility of the photosensitive resin, and the difference in solubility improves contrast and reduces line edge roughness (LER).

[0036] Furthermore, the photosensitive resin and photoresist compositions of the present invention have superior oxide and polysilicon etching resistance compared to conventional resist compositions. DETAILED DESCRIPTION OF THE INVENTION

[0037] Preferred embodiments of the present invention will be described in detail below. In describing the present invention, detailed descriptions of related technologies will be omitted if it is deemed that such descriptions may unnecessarily obscure the gist of the present invention. Throughout this specification, the singular forms "a," "an," and "the" include the plural forms unless the context clearly dictates otherwise. It should be understood that terms such as "including" or "having" are intended to indicate the presence of features, numbers, steps, operations, components, parts, or combinations thereof disclosed herein, and are not intended to exclude the possibility that one or more other features, numbers, steps, operations, components, parts, or combinations thereof may be present or added. Each step of the method described herein may be performed in an order different from that explicitly described. That is, each step may be performed in the same order as described, substantially simultaneously, or in the reverse order.

[0038] The present invention is not limited to the illustrated embodiments, but may be embodied in various different forms. Rather, the disclosed embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, dimensions such as width and thickness of elements may be exaggerated for clarity. The drawings are described from the viewer's perspective. When an element is referred to as being "on" another element, it will be understood that it may be directly on the other element, or that there may be one or more intervening elements therebetween. Those skilled in the art will understand that various changes in form and detail can be made therein without departing from the spirit and scope of the invention, as defined by the appended claims. Like reference numerals refer to substantially like elements throughout the drawings.

[0039] As used herein, the term "and / or" includes both combinations of related disclosed items and any items among related disclosed items. As used herein, the phrase "A or B" means "A," "B," or "A and B."

[0040] The present invention is directed to a photosensitive compound having a structure represented by Formula 1 or Formula 2:

[0041] [ka]

[0042] In the formula, x is 0 or 1, y is an integer of 0 to 3, z is an integer of 1 to 10, m is an integer of 1 to 6, and R1, R2, and R3 are each independently C1 to C 10 of hydrocarbons or OC n H 2n+1 (n is an integer of 0 to 10), and R4 is H or CH3;

[0043] [ka]

[0044] In the formula, x is 0 or 1, y is an integer of 0 to 3, z is an integer of 1 to 10, M is C, O, N, or S, and R1, R2, and R3 are each independently C1 to C 10 of hydrocarbons or OC n H 2n+1 (n is an integer of 0 to 10), and R4 is H or CH3.

[0045] In Formula 1 or Formula 2, x may be 0 or 1. When x is 0, it means that there is no hydrocarbon structure connecting the centers of the cyclohexane moieties in Formula 1 or Formula 2. When x is 1, it means that there is a hydrocarbon structure crossing the cyclohexane.

[0046] In Formula 1 or Formula 2, y represents the number of repeating cyclohexane moieties. When y is 0, it means that one or both carbonyl groups are bonded to the main chain without a cyclohexane moiety.

[0047] When x is 1, y may be 1 or 2. In this case, the photosensitive compound may have a structure in which one or two cyclohexane moieties are linked together, and each cyclohexane moiety may contain a crosslinked structure represented by x.

[0048] In Formula 1, z corresponds to a structure connecting the cyclohexane moiety and the ether bond, and C1 to C 10 The hydrocarbon may be a saturated or unsaturated aliphatic hydrocarbon containing only C and H. Some or all of the hydrogen atoms in the hydrocarbon may be substituted with other atoms or other hydrocarbons. When z is 0, the structural stability decreases, and the overall stability of the compound may decrease. On the other hand, when z in Formula 1 exceeds 10, the structure may be too long, resulting in a decrease in heat resistance.

[0049] In formula 1, m corresponds to the moiety connecting to the Si-containing terminal structure and may be a C1 to C6 hydrocarbon. That is, m is 1 to 6, preferably 2 or 3, and most preferably 3. When m is 0, the compound may become unstable. On the other hand, when m exceeds 6, the heat resistance may decrease.

[0050] In Formula 2, z corresponds to the portion connecting the atom represented by M and the Si-containing terminal structure, and is C1 to C 10 That is, z in formula 2 is 1 to 10, preferably 2 or 3, and most preferably 3. When z is 0 in formula 2, structural stability decreases, and the overall stability of the compound may decrease. On the other hand, when z in formula 2 exceeds 10, the structure is too long, and heat resistance may decrease.

[0051] The Si moiety in Formula 1 or Formula 2 is introduced to improve the thermal stability of the photosensitive compound according to the present invention and to form line edge roughness. The Si moiety may be derived from a compound having a Si atom as a central atom, such as maleic acid. R1, R2, and R3 each independently represent a C1 to C 10 of hydrocarbons or OC n H 2n+1 (n is an integer of 1 to 10). R1, R2, and R3 each independently represent OC n H 2n+1 (n is an integer of 1 to 10), and OC n H 2n+1 It is more preferable that n is 1 or 2.

[0052] The structure of formula 1 or formula 2 is specifically represented by formulas 3 to 34. That is, the photosensitive compound may contain one or more of the compounds represented by formulas 3 to 34: [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka]

[0053] The photosensitive compounds represented by the formulas 1 and 2 can be prepared by a conventional method for preparing organic compounds. The photosensitive compound represented by the formula 1 is preferably a photosensitive compound represented by the formula 3, and can be synthesized as shown in Reaction Scheme 1.

[0054] [ka]

[0055] First, a norbornene-lactone compound is prepared by the Diels-Alder reaction of cyclopentadiene with a furanone anhydride. The norbornene compound is then esterified with water, an alcohol, a thiol, or other reagent, and chloropropyltrimethoxysilane under acidic or basic conditions to prepare a photosensitive compound represented by formula 3. The photosensitive compounds represented by formulas 4 to 18 can be prepared by the same method as described above for the photosensitive compound represented by formula 3.

[0056] The photosensitive compound represented by formula 2 is preferably a photosensitive compound represented by formula 19, which can be synthesized as shown in Reaction Scheme 2.

[0057] [ka]

[0058] First, a norbornene compound is prepared by the Diels-Alder reaction of cyclopentadiene with maleic anhydride. Next, the norbornene compound is esterified with water, an alcohol, a thiol, or other reagent, and chloropropyltrimethoxysilane under acidic or basic conditions to prepare the photosensitive compound represented by formula 19. The photosensitive compounds represented by formulas 20 to 34 can be prepared by the same method as described above for the photosensitive compound represented by formula 19.

[0059] The as-synthesized photosensitive compounds can be used in admixture with photoresist compounds, but are preferably polymerized into a polymer resin before use.

[0060] Thus, a further aspect of the present invention is directed to a photosensitive resin having a structure represented by Formula 35 or Formula 36:

[0061] [ka]

[0062] In the formula, x is 0 or 1, y is an integer of 0 to 3, z is an integer of 1 to 10, m is an integer of 1 to 6, and R1, R2, and R3 are each independently C1 to C 10 of hydrocarbons or OC n H 2n+1 (n is an integer of 0 to 10), R4 is H or CH3, and a represents the molar fraction of repeating units having the structure represented by formula 35 in all repeating units of the photosensitive resin, and is 0.01 to 100 mol %;

[0063] [ka]

[0064] In the formula, x is 0 or 1, y is an integer of 0 to 3, z is an integer of 1 to 10, M is C, O, N, or S, and R1, R2, and R3 are each independently C1 to C 10 of hydrocarbons or OCn H 2n+1 (n is an integer of 0 to 10), R4 is H or CH3, and a represents the molar fraction of repeating units having the structure represented by formula 36 in all repeating units of the photosensitive resin, and is 0.01 to 100 mol %.

[0065] The explanation for x, y, z, m, and M is the same as that for the photosensitive compound described above, and therefore will be omitted.

[0066] In Formula 35 or Formula 36, ​​a represents the molar fraction of repeating units having the structure represented by Formula 35 or Formula 36 among all repeating units of the photosensitive resin. Specifically, it is the ratio of the number of moles of repeating units of Formula 35 or Formula 36 per 100 moles of all repeating units of the photosensitive resin. In other words, a in Formula 35 or Formula 36 represents the molar percentage of repeating units represented by Formula 35 or Formula 36 among all repeating units of the photosensitive resin.

[0067] In Formula 35 or Formula 36, ​​a is preferably 0.01 to 100 mol %, more preferably 1 to 70 mol %. If a in Formula 35 or Formula 36 is less than 0.01 mol %, the effects of the present invention may not be obtained. Note that, when a in Formula 35 or Formula 36 is 100 mol %, this means that the photosensitive resin is composed only of repeating units of Formula 35 or Formula 36.

[0068] The photosensitive resins of formula 35 and formula 36 can be prepared by polymerizing compounds having the structures of formula 1 and formula 2, respectively. That is, the photosensitive resin of formula 35 or formula 36 may contain one or more of the monomers having the structures of formulas 3 to 34 as repeating units.

[0069] The photosensitive resin may have a weight-average molecular weight of 1,000 to 100,000 and a dispersity of 1.0 to 5.0. If the weight-average molecular weight of the photosensitive resin is less than 1,000, it may be difficult to achieve the excellent etching resistance that is the main effect of the present invention. On the other hand, if the weight-average molecular weight of the photosensitive resin exceeds 100,000, the viscosity of the photosensitive resin increases, which may make it difficult to use the photosensitive resin as a photoresist. If the viscosity of the photosensitive resin is outside the above range, the physical properties of the photoresist film formed using the photosensitive resin may deteriorate, or the formation of the photoresist film may become difficult, resulting in a decrease in the contrast of the pattern of the photoresist film.

[0070] The repeating units other than those represented by Formula 1 and Formula 2 constituting the photosensitive resins of Formula 35 and Formula 36 preferably have an acid-sensitive protecting group. Such an acid-sensitive protecting group refers to a dissolution-inhibiting group that is bonded to a side chain of the photosensitive resin and can be removed by acid. The acid-sensitive protecting group can inhibit dissolution of the photoresist composition in an alkaline developer in the unexposed region. In contrast, the acid-sensitive protecting group is deprotected by the catalytic action of the acid generated from the photoacid generator in the exposed region, increasing the solubility of the photoresist composition in a typical alkaline developer, resulting in a large difference in solubility between the exposed and unexposed regions. Photoacid generators will be described later.

[0071] That is, when the acid-sensitive protecting group is bonded to the photoresist material, the photoresist material is prevented from dissolving in an alkaline developer, but the acid-sensitive protecting group is released by the acid generated from the photoacid generator upon stimulation with light, thereby dissolving the photoresist material in the developer.

[0072] The acid-sensitive protecting group is not limited as long as it can fulfill the above-mentioned role. The acid-sensitive protecting group is preferably t-butyl, tetrahydropyran-2-yl, 2-methyltetrahydropyran-2-yl, tetrahydrofuran-2-yl, 2-methyltetrahydrofuran-2-yl, 1-methoxypropyl, 1-methoxy-1-methylethyl, 1-ethoxypropyl, 1-ethoxy-1-methylethyl, 1-methoxyethyl, 1-ethoxyethyl, t-butoxyethyl, 1-isobutoxyethyl, or 2-acetylmenth-1-yl.

[0073] The structure of the photosensitive resin can be represented by the following formula 37 or 38: [ka]

[0074] In the formula, each R4 is independently H or a C1-C6 alkyl group, and R1, R2, and R3 are each independently C1-C 10 Hydrocarbons or OC n H 2n+1 (n is an integer from 1 to 10), and R5 is C1 to C 20 or C5-C 40 R6 and R7 are each independently a cycloalkyl group selected from the group consisting of C1 to C 20 Hydroxyalkyl groups, C1-C 10 or a C5-C halogenated hydroxyalkyl group containing an ether or ester moiety. 10 a, b, c, and d represent the molar fractions of the corresponding repeating units in the total photosensitive compounds of the photosensitive polymer resin, and the ratio is 1-70:1-50:1-50:1-50;

[0075] [ka]

[0076] wherein R1, R2, R3, R4, R5, R6, R7, a, b, c, and d are as defined in Formula 37.

[0077] The presence of silicon in the photosensitive resin of the present invention and the introduction of a norbornene moiety, which is a bulky alicyclic hydrocarbon, into the photosensitive resin of the present invention improves etching resistance and heat resistance, and also improves adhesion to semiconductor substrates. The photosensitive resin of the present invention has a structure in which an organic acid group is present in the silicon-containing norbornene moiety, which is a bulky alicyclic hydrocarbon. This structure makes it easy to control the solubility of the photosensitive resin, and the difference in solubility improves contrast and reduces line edge roughness (LER).

[0078] The photosensitive resin of the present invention can be prepared by a method comprising: i) dissolving the photosensitive compounds represented by Formulas 1 and 2 and the photosensitive compounds represented by R5, R6, and R7 of Formulas 37 and 38 in a polymerization solvent; ii) adding an initiator to the mixed solution; and iii) reacting the mixed solution containing the initiator at a temperature of 60 to 70°C for 4 to 48 hours under a nitrogen or argon atmosphere. The polymerization is preferably carried out by radical polymerization, solution polymerization, bulk polymerization, or ionic polymerization using a metal catalyst. This method may further comprise purifying the reaction product of step iii) by crystallization from diethyl ether, hexane, petroleum ether, alcohol (e.g., methanol, ethanol, or isopropanol), water, or a mixture thereof.

[0079] The polymerization solvent may be selected from a variety of polymerization solvents known in the art. Non-limiting examples of such polymerization solvents include cyclohexanone, cyclopentanone, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, dioxane, methyl ethyl ketone, benzene, toluene, and xylene. These polymerization solvents may be used alone or in combination. The polymerization initiator may be selected from a variety of polymerization initiators known in the art. Non-limiting examples of such polymerization initiators include benzoyl peroxide, 2,2'-azobisisobutyronitrile, acetyl peroxide, lauryl peroxide, t-butyl peracetate, t-butyl hydroperoxide, and di-t-butyl peroxide. These polymerization initiators may be used alone or in combination.

[0080] The photoresist composition of the present invention comprises a photosensitive resin having a structure represented by Formula 35 or Formula 36, ​​a photoacid generator (PAG) that generates an acid, and an organic solvent. The photoresist composition of the present invention may further contain various additives, if desired.

[0081] The photosensitive resin is the same as that described above. The photosensitive resin may be present in an amount of 1 to 30 wt % based on the total weight of the photoresist composition. If the photosensitive resin is present in an amount less than 1 wt %, it may be difficult to form a pattern using the photoresist composition. On the other hand, if the photosensitive resin is present in an amount greater than 30 wt %, the viscosity of the photoresist composition increases, making it difficult to form an appropriate pattern.

[0082] The photoacid generator generates H +The photoacid generator generates an acid component such as an organic sulfonic acid, an onium salt compound such as an onium salt, or a mixture thereof, to cause chemical amplification. The photoacid generator may be any compound capable of generating an acid by light. The photoacid generator is preferably a sulfide salt compound such as an organic sulfonic acid, an onium salt compound such as an onium salt, or a mixture thereof. Non-limiting examples of suitable photoacid generators include phthalimidotrifluoromethanesulfonic acid, dinitrobenzyl tosylate, n-decyl disulfone, naphthylimidotrifluoromethanesulfonic acid, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroarsenate, diphenyliodonium hexafluoroantimonate, diphenyl-p-methoxyphenylsulfonium triflate, diphenyl-p-toluenylsulfonium triflate, diphenyl-p-isobutylphenylsulfonium triflate, triphenylsulfonium hexafluoroarsenate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium triflate, and dibutylnaphthylsulfonium triflate, which exhibit low absorbance at 157 nm and 193 nm. These photoacid generators may be used alone or in combination. The content of the photoacid generator is preferably 0.1 to 20 parts by weight per 100 parts by weight of the photosensitive resin. If the content of the photoacid generator is less than 0.1 parts by weight, the photosensitivity of the photoresist composition to light may decrease, making it difficult to deprotect the protecting groups, whereas if the content of the photoacid generator is more than 20 parts by weight, a large amount of acid may be generated from the photoacid generator, which may damage the cross section of the formed photoresist pattern.

[0083] The organic solvent constitutes the remainder of the photoresist composition according to the present invention. The organic solvent may be selected from a variety of organic solvents commonly used in the preparation of photoresist compositions. Non-limiting examples of such organic solvents include ethylene glycol monomethyl ethyl, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether acetate (PGMEA), toluene, xylene, methyl ethyl ketone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethoxyethyl acetate, hydroxyethyl acetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxy-2-methylpropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxy-2-methylpropionate, ethyl acetate, and butyl acetate. These organic solvents may be used alone or in combination.

[0084] The photoresist composition of the present invention may further contain an organic base, if desired. Non-limiting examples of such organic bases include triethylamine, triisobutylamine, triisooctylamine, diethanolamine, and triethanolamine. These organic bases may be used alone or in combination. The content of the organic base is preferably 0.01 to 10 wt % based on the total weight of the photoresist composition. If the content of the organic base is less than 0.01 wt %, the so-called T-top phenomenon may occur in the photoresist pattern formed using the photoresist composition. On the other hand, if the content of the organic base exceeds 10 wt %, the sensitivity of the photoresist composition may decrease, resulting in reduced processability and productivity.

[0085] The chemically amplified photoresist composition of the present invention comprises a blend of a photosensitive resin, a photoacid generator, an organic solvent, and, if desired, various additives. The chemically amplified photoresist composition of the present invention is preferably prepared so that its solids content is 1 to 30 wt % based on the total weight of the photoresist composition. The chemically amplified photoresist composition of the present invention is optionally filtered through a 0.2 μm filter before use.

[0086] The photoresist composition of the present invention can be used to form a photoresist thin film and pattern by the following procedure.

[0087] First, i) the photoresist composition of the present invention is applied to the surface of a layer to be etched, such as a silicon wafer or an aluminum substrate, using a spin coater to form a thin film, ii) the thin film is exposed to a short-wavelength light source, iii) the exposed photoresist film is heated as needed, and iv) the heated resist film is developed to form a photoresist pattern.

[0088] The method for forming a photoresist pattern may further include pre-baking the resist film after the coating step (i) and before the exposure step (ii). The pre-baking step and the step (iii) of heating the exposed photoresist are preferably carried out at 70 to 200°C. If the heating temperature is less than 70°C, the organic solvent present in the photoresist composition may not evaporate sufficiently. On the other hand, if the heating temperature exceeds 200°C, the photoresist composition may be thermally decomposed.

[0089] The developer used in the development step iv) may be any developer known in the art. The developer is preferably an alkaline developer, more preferably an aqueous solution of tetramethylammonium hydroxide (TMAH). The concentration of the developer is preferably 0.1 to 10% by weight. The developer may contain an appropriate amount of a water-soluble organic solvent such as methanol or ethanol and a surfactant.

[0090] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention. In describing the present invention, detailed descriptions of related known functions and configurations will be omitted if it is determined that such descriptions may unnecessarily obscure the gist of the present invention. Certain features shown in the drawings have been enlarged, reduced, or simplified to facilitate explanation, and the drawings and their elements are not necessarily in appropriate proportions. However, such details will be easily understood by those skilled in the art. [Example]

[0091] Example 1 Preparation of photosensitive compound (Formula 3) 1) Preparation of norbornene-lactone compounds As shown in Reaction Scheme 1, 130 g of cyclopentadiene was added dropwise to a reactor containing an equal equivalent of anhydrous furanone and 1 L of benzene. The mixture was stirred while undergoing the Diels-Alder reaction. The reactor was cooled in a dry ice bath. After the addition was completed, the temperature of the reaction mixture was raised to room temperature. The reaction was continued at room temperature for 24 hours with stirring to obtain the norbornene-lactone compound (yield 88%). [H-NMR (CDCl3): δ (ppm), 6.23 (CH, 2H), 3.77 (CH, 1H), 2.58 (CH, 1H), 1.75 (CH2, 2H), 2.31 (CH, 1H), 2.11 (CH, 1H), 4.38 (CH2, 2H)]

[0092] 2) Preparation of photosensitive compound (Formula 3) As shown in Reaction Scheme 1, 0.3 mol (45.05 g) of the norbornene-lactone compound obtained in Example 1 and 0.32 mol (46.79 g) of triethylamine were dissolved in 200 mL of THF, and 0.32 mol (63.59 g) of 3-chloropropyltrimethoxysilane was added dropwise. The reaction was allowed to proceed at room temperature. After completion of the reaction, the THF was removed by distillation under reduced pressure. Water was added to the reaction mixture, which was then neutralized with dilute hydrochloric acid, extracted with ethyl acetate, dried over anhydrous MgSO4, and purified by column chromatography to obtain the photosensitive compound represented by Formula 3 (yield 73%). [H-NMR (CDCl3): δ (ppm), 6.23 (CH, 2H), 3.46 (CH, 1H), 2.58 (CH, 1H), 1.75 (CH2, 2H), 2.40 (CH, 1H), 2.18 (CH, 1H), 3.46 (CH2, 2H), 2.66 (CH2, 6H), 3.55 (CH3, 9H), 11.0 (OH, 1H)]

[0093] (Examples 2 to 16) The photosensitive compounds represented by formulas 4 to 18 were synthesized in the same manner as in Example 1. The structures of the photosensitive compounds were confirmed by H-NMR. The results are shown in Table 1. The yields of the photosensitive compounds are also shown in Table 1.

[0094] [Table 1-1]

[0095] [Table 1-2]

[0096] Example 17 Preparation of photosensitive compound (Formula 19) 1) Preparation of norbornene compounds As shown in Reaction Scheme 2, 130 g of cyclopentadiene was added dropwise to a reactor containing an equal equivalent of maleic anhydride and 1 L of benzene. The mixture was stirred while undergoing the Diels-Alder reaction. The reactor was cooled in a dry ice bath. After the addition was completed, the temperature of the reaction mixture was raised to room temperature. The reaction was continued at room temperature for 24 hours with stirring to obtain the norbornene compound (yield 92%). [H-NMR (CDCl): δ (ppm), 6.23 (CH, 2H), 3.77 (CH, 2H), 1.75 (CH, 2H), 3.02 (CH, 2H)]

[0097] 2) Preparation of photosensitive compound (Formula 19) As shown in Reaction Scheme 2, 0.3 mol (49.25 g) of the norbornene compound obtained in Example 17 and 0.32 mol (46.79 g) of triethylamine were dissolved in 250 mL of THF, and 0.32 mol (63.59 g) of 3-chloropropyltrimethoxysilane was added dropwise. The reaction was allowed to proceed at room temperature. After completion of the reaction, the THF was removed by distillation under reduced pressure. Water was added to the reaction mixture, which was then neutralized with dilute hydrochloric acid. The mixture was extracted with ethyl acetate, dried over anhydrous MgSO4, and purified by column chromatography to obtain the photosensitive compound represented by Formula 19 (yield 73%). [H-NMR (CDCl3): δ (ppm), 6.23 (CH, 2H), 3.46 (CH, 1H), 3.36 (CH, 1H), 1,75 (CH2, 2H), 2.63 (CH, 1H), 2,72 (CH, 1H), 2.5 (CH2, 2H), 0.86 (CH2, 4H), 3.55 (CH3, 9H), 11.0 (OH, 1H)]

[0098] (Examples 18 to 32) Photosensitive resins represented by Formulae 20 to 34 were synthesized in the same manner as in Example 17. The structures of the photosensitive compounds were confirmed by H-NMR. The results are shown in Table 2. The yields of the photosensitive compounds are also shown in Table 2.

[0099] [Table 2-1]

[0100] [Table 2-2]

[0101] Example 33 Preparation of photosensitive polymer resin 62.57 g (0.198 mol) of the photosensitive compound represented by Formula 3, 75.45 g (0.322 mol) of 2-methyl-2-adamantyl methacrylate, 46.79 g (0.198 mol) of hydroxyadamantyl methacrylate, and 12 g of azobis(isobutyronitrile) (AIBN) were dissolved in 120 g of anhydrous THF. The reaction mixture was degassed by freezing in an ampoule and then polymerized at 66°C for 12 hours. The polymerization mixture was slowly added dropwise to excess diethyl ether. The resulting precipitate was dissolved in THF and reprecipitated in diethyl ether to obtain a photosensitive polymer resin (Mn = 4739, Mw = 8531, PDI = 1.80 by GPC analysis).

[0102] Example 34 Preparation of photosensitive polymer resin A photosensitive polymer resin (Mn=4701, Mw=8312, PDI=1.77 by GPC analysis) was obtained in the same manner as in Example 33, except that 65.34 g (0.198 mol) of the photosensitive compound represented by Formula 7 was used.

[0103] Example 35 Preparation of photosensitive polymer resin A photosensitive polymer resin (Mn=4715, Mw=8632, PDI=1.83 by GPC analysis) was obtained in the same manner as in Example 33, except that 75.64 g (0.198 mol) of the photosensitive compound represented by Formula 11 was used.

[0104] Example 36 Preparation of photosensitive polymer resin A photosensitive polymer resin (Mn=4551, Mw=7345, PDI=1.65 by GPC analysis) was obtained in the same manner as in Example 33, except that 78.41 g (0.198 mol) of the photosensitive compound represented by Formula 15 was used.

[0105] Example 37 Preparation of photosensitive polymer resin A photosensitive polymer resin (Mn=4571, Mw=8332, PDI=1.82 by GPC analysis) was obtained in the same manner as in Example 33, except that 62.17 g (0.198 mol) of the photosensitive compound represented by Formula 19 was used.

[0106] Example 38 Preparation of photosensitive polymer resin A photosensitive polymer resin (Mn=3857, Mw=7243, PDI=1.88 by GPC analysis) was obtained in the same manner as in Example 33, except that 75.24 g (0.198 mol) of the photosensitive compound represented by Formula 23 was used.

[0107] Example 39 Preparation of photosensitive polymer resin A photosensitive polymer resin (Mn=4957, Mw=9112, PDI=1.84 by GPC analysis) was obtained in the same manner as in Example 33, except that 62.14 g (0.198 mol) of the photosensitive compound represented by Formula 27 was used.

[0108] Example 40 Preparation of photosensitive polymer resin A photosensitive polymer resin (Mn=4832, Mw=8453, PDI=1.75 by GPC analysis) was obtained in the same manner as in Example 33, except that 78.21 g (0.198 mol) of the photosensitive compound represented by Formula 31 was used.

[0109] (Examples 41 to 48) Preparation of chemically amplified photoresist compositions 2 g of each photosensitive polymer resin obtained in Examples 33 to 40 and 0.02 g of triphenylsulfonium triflate were completely dissolved in 20 g of propylene glycol monomethyl ether acetate (PGMEA). The solution was then filtered through a 0.2 μm disk filter to obtain a chemically amplified photoresist composition. The photoresist composition was coated to a thickness of approximately 0.2 μm on a silicon wafer treated with hexamethyldisilazane. The wafer coated with the photoresist composition was prebaked at 120°C for 90 seconds, exposed to an ArF excimer laser with a numerical aperture of 0.60, heated at 120°C for 90 seconds (PEB), and developed in a 2.38 wt% tetramethylammonium hydroxide (TMAH) solution for 30 seconds to obtain a photoresist pattern with uniform line and space (L / S) (0.1 μm).

[0110] (Comparative Example 1) A chemically amplified photoresist composition was prepared in the same manner as in Example 41, except that a conventional photosensitive polymer resin (Mn=5105, Mw=9874, PDI=1.93 by GPC analysis) prepared from 2-methyl-2-adamantyl methacrylate and γ-butyrolactone methacrylate was used instead of the photosensitive resin obtained in Example 33.

[0111] (Experimental Example 1) The weight average molecular weight (Mw), number average molecular weight (Mn), and polydispersity index (PDI) were measured for each of the polymer resins used in Examples 41 to 48 and Comparative Example 1. In addition, the LER (unit: mm) and etching resistance of patterns formed using the resist compositions prepared in Examples 41 to 48 and Comparative Example 1 were measured.

[0112] To measure LER and etching resistance, each resist composition prepared in Examples 41 to 48 and Comparative Example 1 was coated onto a wafer, prebaked at 130°C for 90 seconds, exposed to an ArF excimer laser with a numerical aperture of 0.60, baked at 130°C for 90 seconds (post-exposure bake (PEB)), and developed in a 2.38 wt% tetramethylammonium hydroxide (TMAH) solution for 30 seconds to obtain a pattern with 1:1 line and space (0.14 μm). The LER and etching resistance of the pattern were measured. The results are shown in Table 3.

[0113] [Table 3]

[0114] As can be seen from the results in Table 3, the presence of silicon in the photosensitive resin of the present invention and the introduction of a norbornene moiety, which is a bulky alicyclic hydrocarbon, into the photosensitive resin of the present invention improved etching resistance. The improved etching resistance improves heat resistance and adhesion to the semiconductor substrate. Furthermore, because the photosensitive resin of the present invention has a structure in which an organic acid group is present in the silicon-containing norbornene moiety, which is a bulky alicyclic hydrocarbon, it is easy to control the solubility of the photosensitive resin. It was confirmed that the difference in solubility improves contrast and reduces line edge roughness (LER).

[0115] Although the features of the present invention have been described in detail, it will be apparent to those skilled in the art that such features are merely preferred embodiments and are not intended to limit the scope of the invention, the true scope of which is therefore defined by the appended claims and their equivalents. <Additional Notes> The present invention includes the following aspects. <Section 1> A photosensitive compound having a structure represented by Formula 1 or Formula 2: [ka] In the formula, x is 0 or 1, y is an integer of 0 to 3, z is an integer of 1 to 10, m is an integer of 1 to 6, and R 1 、R2 , and R 3 are each independently C 1 ~C 10 of hydrocarbons or OC n H 2n+1 (n is an integer from 0 to 10), and R 4 is H or CH 3 and;

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Claims

1. A photosensitive resin having a structure represented by Formula 35 or Formula 36: 【Chemistry 1】 In the formula, x is 0 or 1, y is an integer from 0 to 3, z is an integer from 1 to 10, m is an integer from 1 to 6, and R １ , R ２ , and R ３ are each independently C １ ~C １０ hydrocarbons or OC ｎ H ２ｎ＋１ (n is an integer from 1 to 10), and R ４ is H or CH ３ a represents the molar fraction of repeating units having the structure represented by formula 35 in all repeating units of the photosensitive resin, and is 0.01 to 100 mol %; 【Chemistry 2】 In the formula, x is 0 or 1, y is an integer from 0 to 3, z is an integer from 1 to 10, M is C, O, N, or S, and R １ , R ２ , and R ３ are each independently C １ ~C １０ hydrocarbons or OC ｎ H ２ｎ＋１ (n is an integer from 1 to 10), and R ４ is H or CH ３ a represents the molar fraction of repeating units having the structure represented by formula 36 in all repeating units of the photosensitive resin, and is 0.01 to 100 mol %. Photosensitive resin.

2. The photosensitive resin comprises a structure represented by Formula 37 or Formula 38: 【Transformation 3】 In the formula, each R ４ are independently H or C １ ~C ６ is an alkyl group, and R １ , R ２ , and R ３ are each independently C １ ~C １０ Hydrocarbon or OC ｎ H ２ｎ＋１ (n is an integer from 1 to 10), and R ５ is C １ ~C ２０ or an alkyl group of C ５ ~C ４０ is a cycloalkyl group of the formula R ６ and R ７ are each independently １ ~C ２０ hydroxyalkyl groups of C １ ~C １０ or a halogenated hydroxyalkyl group of C containing an ether or ester moiety ５ ~C １０ a, b, c, and d represent the molar fractions of the corresponding repeating units in the total photosensitive compounds of the photosensitive polymer resin, and the ratio is 1-70:1-50:1-50:1-50; 【Chemistry 4】 In the formula, R １ , R ２ , R ３ , R ４ , R ５ , R ６ , R ７ , a, b, c, and d are as defined in Equation 37; The photosensitive resin according to claim 1 .

3. 2. The photosensitive resin according to claim 1, wherein a is 1 to 70 mol %.

4. 2. The photosensitive resin according to claim 1, wherein the weight average molecular weight of the photosensitive resin is 1,000 to 100,000.

5. A photoresist composition comprising a photosensitive resin having a structure represented by Formula 35 or Formula 36, ​​a photoacid generator, and an organic solvent: 【Transformation 5】 In the formula, x is 0 or 1, y is an integer from 0 to 3, z is an integer from 1 to 10, m is an integer from 1 to 6, and R １ , R ２ , and R ３ are each independently C １ ~C １０ hydrocarbons or OC ｎ H ２ｎ＋１ (n is an integer from 1 to 10), and R ４ is H or CH ３ a represents the molar fraction of repeating units having the structure represented by formula 35 in all repeating units of the photosensitive resin, and is 0.01 to 100 mol %; 【Transformation 6】 In the formula, x is 0 or 1, y is an integer from 0 to 3, z is an integer from 1 to 10, M is C, O, N, or S, and R １ , R ２ , and R ３ are each independently C １ ~C １０ hydrocarbons or OC ｎ H ２ｎ＋１ (n is an integer from 1 to 10), and R ４ is H or CH ３ a represents the molar fraction of repeating units having the structure represented by formula 36 in all repeating units of the photosensitive resin, and is 0.01 to 100 mol %. Photoresist compositions.

6. The photoresist composition of claim 5, wherein the photosensitive resin is present in an amount of 1 to 30 weight percent, based on the total weight of the photoresist composition.

7. 6. The photoresist composition of claim 5, wherein the photoacid generator is selected from organic sulfonic acids, sulfide salt compounds, onium salt compounds, and mixtures thereof, and is present in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the photosensitive resin.

8. 6. The photoresist composition of claim 5, wherein the organic solvent is selected from the group consisting of ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethoxyethyl acetate, hydroxyethyl acetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxy-2-methylpropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxy-2-methylpropionate, ethyl acetate, butyl acetate, and mixtures thereof.

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