Pattern profile and chemically amplified positive photoresist composition for resolution improvement

Abstract

The chemically amplified positive photoresist composition for improving pattern profile and resolution of the present invention comprises, relative to the total weight of the composition, 5 to 60% by weight of a polymer resin, 0.1 to 5% by weight of an acid generating auxiliary monomer additive for the lower part of a pattern represented by Chemical Formulae 1 to 3, 0.05 to 10% by weight of a photoacid generator, 0.01 to 5% by weight of an acid diffusion inhibitor, and the remainder being a solvent. This composition has an effect of providing a composition which has a vertical profile, improved resolution and sensitivity as well as an excellent process margin without residual scum as compared to conventional positive photoresists.

Description

Technical Field

[0001] The present invention relates to a chemically amplified positive photoresist composition for improving pattern profile and resolution.

Background Art

[0002] Recently, with the development of semiconductor manufacturing process technology, the miniaturization and high integration of semiconductor devices have been required. Accordingly, technologies for implementing ultra-fine patterns having a line width of several tens of nm or less have been demanded. The progress of technologies for forming such ultra-fine patterns has been made by a light source having a smaller wavelength, the development of process technology using the light source, the development of a photoresist suitable for the light source, and the like. A photoresist is used in a photolithography process for forming various patterns. The photoresist means a photosensitive resin whose solubility in a developer changes by the action of light and an image corresponding to an exposure pattern is obtained. As a method for forming a pattern of the photoresist, there are a method using a negative developer (NTD, Negative Tone Development) and a method using a positive developer (PTD, Positive Tone Development). The pattern formation method using the negative developer forms a pattern by selectively dissolving and removing an unexposed area with the negative developer. The pattern formation method using the positive developer forms a pattern by selectively dissolving and removing an exposed area with the positive developer. When the pattern formation method using the negative developer is compared with the pattern formation method using the positive developer, even in the case of a contact hole pattern or a trench pattern that is difficult to form with insufficient exposure amount, by implementing an inverted pattern, it is easy to form a pattern when implementing the same pattern. Since an organic solvent is used as a developer for removing an unexposed portion, a photoresist pattern can be formed more effectively. On the one hand, generally, a photolithography process using a photoresist composition includes a process of coating a photoresist on a wafer, a soft bake process of heating the coated photoresist to evaporate the solvent, a process of imaging with a light source passing through a photomask, a process of forming a pattern by the difference in solubility between the exposed portion and the unexposed portion using a developer, and a process of etching this to complete the circuit. The photoresist composition consists of a photo acid generator that generates an acid upon irradiation with an excimer laser, a base resin, and other additives. The base resin has a structure with a hydroxyl group in the phenol structure, and a polystyrene polymer is basically used. As the photo acid generator, any one that can generate an acid (H + ) at a specific wavelength may be used, and mainly sulfonium salt-based, sulfonyldiazo-based, benzosulfonyl-based, iodine-based, chlorine-based, carboxylic acid-based, etc. are mainly used. In addition, the light sources mainly used in the above processes are in the wavelength range of 365 nm to 193 nm using I-line, KrF excimer laser, and ArF excimer laser light sources. It is known that the shorter the wavelength, the finer the pattern that can be formed. In particular, even after the subsequent development of ArF laser (193 nm) systems, research and development efforts to pursue optical microfabrication using KrF lasers (243 nm) have been continuously advanced. One reason for this is that the development of next-generation ArF photoresists is not yet satisfactory, and another reason is that using KrF photoresists as they are can result in significant cost savings in semiconductor mass production. To support such technological development, the performance of KrF photoresists must also be improved. For example, typically, as integration density increases, the thickness of the photoresist is gradually required to decrease, so there is an urgent need to develop photoresists with enhanced dry etching resistance. In addition to this, required characteristics include high resolution, a wide depth of focus (DOF) margin, defect-free thin film formation, adhesion to the substrate, high contrast, high speed sensitivity, chemical stability, and so on.

[0003] As described above, conventional patents related to KrF photoresist technology include Korean Patent Publication No. 10-2010-0047038, "Chemically Amplified Positive Photoresist Composition"; Korean Patent Registration No. 10-1363842, "Chemically Amplified Positive Photoresist Composition and Resist Pattern Forming Method Using the Same"; Korean Patent Registration No. 10-1204915, "Photoresist Polymer, Photoresist Composition Containing the Same, and Photoresist Pattern Forming Method Using the Same"; Korean Patent Registration No. 10-0273108, "Copolymer for Photoresist Production and Chemically Amplified Positive Photoresist Composition Containing the Same"; Korean Patent Registration No. 10-1655947, "Negative Resist Composition for KrF Laser Having High Resolution and High Aspect Ratio"; Korean Patent Registration No. 10-1977886, "Chemically Amplified Positive Photoresist Composition for Pattern Profile Improvement", etc. As also described in the above patents, KrF photoresists mainly use polyhydroxystyrene and polystyrene polymers with good transmittance at a wavelength of 248 nm as the basic polymers to improve resolution and sensitivity. Such positive photoresists based on polyhydroxystyrene and polystyrene polymers have a problem that their usable range in a process based on a 248 nm light source is limited due to, for example, the shape of a slope pattern or a footing phenomenon, and as the thickness of the photoresist increases, the achievable resolution decreases, making it difficult to progress the process.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present invention is to introduce an acid generation auxiliary agent to the lower part of a pattern effective in improving a pattern profile and resolution, and by adding an appropriate amount, to provide a photoresist composition for a KrF light source capable of improving resolution as compared with an existing KrF positive photoresist. Another object of the present invention is to provide a photoresist composition for a KrF light source capable of ensuring a vertical profile and effective in removing residual scum at the lower part of a pattern.

Means for Solving the Problems

[0006] In order to achieve the above object, the present invention provides a positive photoresist composition for KrF, which contains one or more acid generation auxiliary monomer additives for the lower part of the pattern for chemically amplified resist, selected from the group represented by the following Chemical Formulas 1 to 3 and having a weight average molecular weight of 100 to 500.

Chemical Formula

Chemical Formula

Chemical Formula

[0007] (In the above Chemical Formulas 1 to 3, R 1 ~R 3 are structures selected from the structures of the following Chemical Formulas A to E, and R represents a bonding site.)

Chemical Formula

Chemical Formula

Chemical Formula

Chemical Formula

Chemical Formula

[0008] In a preferred embodiment of the present invention, the acid generation auxiliary monomer additives for the lower part of the pattern for resist represented by the above chemical formulas and similar structures are commercially available from many suppliers at home and abroad. In a preferred embodiment of the present invention, the acid generation assisting monomer additive at the lower part of the resist pattern represented by the chemical formula is characterized in that the weight average molecular weight is 100 to 500. In a preferred embodiment of the present invention, the acid generation assisting monomer additive at the lower part of the resist pattern contains, based on the total weight of the composition, 5 to 60% by weight of a polymer resin, 0.1 to 5% by weight of one or more acid generation assisting monomer additives at the lower part of the pattern selected from the group represented by Chemical Formulas 1 to 3, 0.05 to 10% by weight of a photoacid generator, and 0.01 to 5% by weight of an acid diffusion inhibitor, and the balance is composed of a solvent. In a preferred embodiment of the present invention, the polymer resin may be any generally used photoresist resin, and is characterized in that it is one or more selected from the group consisting of phenolic polymer resins containing a hydroxyl group represented by the following Chemical Formulas 4 to 8.

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0009] (In the above Chemical Formula 5, c and d are in a molar ratio of 1 to 10 of the repeating units forming the copolymer, where c + d = 10, R 5 is the same as R 4 and is any one structure selected from the structures of the above Chemical Formulas a to p, and R represents the bonding site.) [Chemistry] (In the above Chemical Formula 6, e, f, and g are in a molar ratio of 1 to 10 of the repeating units forming the copolymer, where e + f + g = 10, R 6 , R 7 are R4 It is the same as the above, and is any one structure selected from the structures of the chemical formulas a to p, and R represents a bonding site.)

Chemical formula

[0010] (In the chemical formula 7, h, i, and j are in the molar ratio of the repeating units forming the copolymer and are 1 to 10, and h + i + j = 10, and R 8 , R 9 is the same as R 4 and is any one structure selected from the structures of the chemical formulas a to p, and R represents a bonding site.)

Chemical formula

[0011] In a preferred embodiment of the present invention, the photoacid generator is Triphenylsulfonium triflate, Triphenylsulfonium antimonate, Diphenyliodonium triflate, Diphenyliodonium antimonate, Methoxydiphenyliodonium triflate, Di-t-butyldiphenyliodonium triflate, Norbornenedicarboxyimide triflate, Triphenylsulfonium nonaflate, Diphenyliodonium nonaflate, Methoxydiphenyliodonium nonaflate, Di-t-butyldiphenyliodonium nonaflate, N-hydroxysuccinimide nonaflate, Norbornenedicarboxyimide nonaflate, Triphenylsulfonium perfluorooctanesulfonate, Diphenyliodonium perfluorooctanesulfonate, Methoxydiphenyliodonium perfluorooctanesulfonate, Di-t-butyldiphenyliodonium perfluorooctanesulfonateIt is characterized by containing one or more selected from the group consisting of N-hydroxysuccinimide perfluorooctanesulfonate and norbornenedicarboxyimide perfluorooctanesulfonate.

[0012] In a preferred embodiment of the present invention, the acid diffusion inhibitor is characterized by containing one or more selected from the group consisting of dimethylamine, diethylamine, trimethylamine, triethylamine, tributhylamine, dimethanolamine, diethanolamine, trimethanolamine, triethanolamine, and tributhanolamine.

Advantages of the Invention

[0013] The chemically amplified positive photoresist composition for improving pattern profile and resolution, which contains the acid generation assisting monomer additive at the bottom of the pattern according to the present invention, can obtain a vertical profile by exposure energy, has the effects of improving sensitivity and resolution, and also has the effect of removing residual scum at the bottom of the pattern. Therefore, the process margin can be improved compared with the existing KrF positive photoresist.

Embodiments for Carrying out the Invention

[0014] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is well known and commonly employed in the art. Throughout the specification of the present application, when a part states that a certain component "includes", unless otherwise stated to the contrary, this does not exclude other components, but means that other components can be further included. The "acid generation assisting monomer additive" at the lower part of the pattern presented in the present invention means an additive that is decomposed by heat in the PEB (Post Exposed Bake) process that proceeds after the process of exposing to a 248 nm light source of krypton fluoride (KrF), and thus generates an acid (H + ). In the present invention, "photoresist" is a mixture of a polymer and a photoacid generator. When its chemical properties change upon exposure to light and it is exposed to light of a specific wavelength, its solubility in a specific solvent changes. However, a difference in the dissolution rate between the exposed part and the unexposed part in the solvent occurs, and after a certain dissolution time, the unmelted part remains, meaning that pattern formation is performed. In the present invention, the "photolithographic process" means that a mask engraved with a semiconductor design drawing using the properties of the photoresist as described above is placed between a light source and a photoresist film coated on a silicon wafer. When the light source is turned on, the circuit engraved on the mask is transferred to the photoresist as it is. In the present invention, "KrF laser" means a krypton fluoride (KrF) laser having a wavelength of 248 nm.

[0015] One embodiment of the present invention provides a chemically amplified positive photoresist composition for improving pattern profile and resolution, which comprises at least one acid generation assisting monomer additive selected from the group represented by the following Chemical Formulas 1 to 3.

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

[0016] The positive photoresist composition for pattern profile and resolution containing the acid generation assisting monomer additive at the bottom of the pattern according to the present invention contains 5 to 60% by weight of a polymer resin, 0.1 to 5% by weight of at least one acid generation assisting monomer additive at the bottom of the pattern selected from the group represented by Chemical Formulas 1 to 3, 0.05 to 10% by weight of a photoacid generator, and 0.01 to 5% by weight of an acid diffusion inhibitor, based on the total weight of the composition, and the balance may consist of a solvent. It is preferable that the acid generation assisting monomer additive at the lower part of one or more patterns selected from the group represented by the chemical formulas 1 to 3 contains 0.1 to 5% by weight based on the total weight of the composition. If the compound is used in an amount less than 0.1% by weight, since the amount of the acid generation assisting monomer additive at the lower part of the pattern is too small, not only the vertical profile cannot be ensured, but also there is no effect on improving the resolution. If it is used in an amount exceeding 5% by weight, although it is possible to ensure a vertical profile, it is not preferable because it causes pattern collapse or undercut generation due to excessive acid generation in other lower parts of the pattern. The polymer resin may be any commonly used photoresist resin, and is characterized by being one or more selected from the group consisting of phenolic polymer resins containing a hydroxyl group represented by the following chemical formulas 4 to 8. [Chemical formula] (In the chemical formula 4, a and b are 1 to 10 in the molar ratio of the repeating units forming the copolymer, and a + b = 10, and R 4 is any one structure selected from the structures of the following chemical formulas a to p, and R represents a bonding site.) [Chemical formula] [Chemical formula] [Chemical formula] [Chemical formula] [Chemical formula] [Chemical formula]

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

[0017] (In the above chemical formula 5, c and d are molar ratios of repeating units forming the copolymer, where 1 ≤ c, d ≤ 10 and c + d = 10, R 5 is the same as R 4 and is any one structure selected from the structures of the above chemical formulas a - p, and R represents the bonding site.)

Chem.

Chemical formula

[0018] (In the above chemical formula 7, h, i, and j are in a molar ratio of repeating units forming a copolymer and are 1 to 10, and h + i + j = 10, and R 8 , R 9 is the same as R 4 and is any one structure selected from the structures of the above chemical formulas a to p, and R represents a bonding site.)

Chemical formula

[0019] The photoacid generator is triphenylsulfonium triflate, triphenylsulfonium antimonate, diphenyliodonium triflate, diphenyliodonium antimonate, methoxydiphenyliodonium triflate, di-t-butyldiphenyliodonium triflate, norbornenedicarboxyimide triflate, triphenylsulfonium nonaflate, diphenyliodonium nonaflate, methoxydiphenyliodonium nonaflate, di-t-butyldiphenyliodonium nonaflate, N-hydroxysuccinimide nonaflate, norbornenedicarboxyimide nonaflate, triphenylsulfonium perfluorooctanesulfonate, diphenyliodonium perfluorooctanesulfonate, methoxydiphenyliodonium perfluorooctanesulfonate, di-t-butyldiphenyliodonium perfluorooctanesulfonate,It may also contain one or more selected from the group consisting of N-hydroxysuccinimide perfluorooctanesulfonate and norbornenedicarboxyimide perfluorooctanesulfonate.

[0020] Preferably, the photoacid generator contains 0.05 to 10% by weight of the photoacid generator based on the total weight of the composition. If the photoacid generator is used in an amount less than 0.05% by weight, a phenomenon may occur in which the inclined surface of the pattern deteriorates due to insufficient acid generation. If the amount exceeds 10% by weight, problems such as pattern defects may occur, such as the photoacid generator absorbing the light of the exposure light source and reducing the transmittance, resulting in no definition. The acid diffusion inhibitor may contain one or more selected from the group consisting of dimethylamine, diethylamine, trimethylamine, triethylamine, tributhylamine, dimethanolamine, diethanolamine, trimethanolamine, triethanolamine, and tributhanolamine. Preferably, the acid diffusion inhibitor contains 0.01 to 5% by weight of the acid diffusion inhibitor based on the total weight of the composition. If the acid diffusion inhibitor is used in an amount less than 0.01% by weight, problems such as pattern defects may occur, such as pattern defects (LWR, LER) on the wall surface or corners of the pattern due to excessive acid generation. If the amount exceeds 5% by weight, there may be a problem that pattern formation may not be possible.

[0021] On the one hand, the thickness of the chemically amplified positive photoresist composition for improving the pattern profile and resolution, which contains an acid generation auxiliary monomer additive at the lower part of the pattern of the present invention, can be used in the range of 2,000 Å to 200,000 Å depending on the type and amount of the solvent used, and it can be used after dissolving at 10 to 90% by weight based on the weight of the solvent. As the solvent, Ethyleneglycolmonomethylether, Ethyleneglycolmonoethylether, Methylcellosolveacetate, Ethylcellosolveacetate, Diethyleneglycolmonomethylether, Diethyleneglycolmonoethylether, PropyleneglycolMonomethylether, Propyleneglycolmethyletheracetate, Propyleneglycolpropyletheracetate, Diethyleneglycoldimethylether, Ethyllactate, Toluene, Xylene, Methylethylketone, Cyclohexanone, 2 - heptanone, 3 - heptanone, 4 - heptanone, etc. can be used, and they can be used alone or in combination. As described above, the pattern profile and the chemically amplified positive photoresist composition for improving resolution containing the acid generation assisting monomer additive at the lower part of the pattern provided by the present invention can obtain a vertical profile by exposure energy by adding one or more acid generation assisting monomers selected from the group represented by Chemical Formulas 1 to 3, and is also effective in improving resolution and removing residual scum at the lower part of the pattern. Therefore, it can provide a process margin for existing KrF photoresists.

Examples

[0022] [Examples and Comparative Examples] Hereinafter, the present invention will be described in more detail by way of examples. It is obvious to those with ordinary knowledge in the industry that these examples are merely for illustrating the present invention, and the scope of the present invention should not be construed as being limited by these examples. Example 1 100 g of a phenolic polymer resin having a weight average molecular weight of 15,000 as a base resin (in Chemical Formula 7, R 8 is Chemical Formula a, R 9 is Chemical Formula c, and the copolymerization molar ratios h, i, j are 7, 2, 1 respectively), 100 g of an acid generation assisting monomer additive at the lower part of the pattern having a weight average molecular weight of 270 (in Chemical Formula 1, R 11.00 g of a structure having the chemical formula d, 4 g of triphenylsulfonium nonaflate as a photoacid generator, and 0.6 g of triethanolamine as an acid diffusion inhibitor were used. As a solvent, a mixed solution of 105 g of propylene glycol monomethyl ether and 105 g of propylene glycol methyl ether acetate was used to produce a positive photoresist composition for KrF excimer laser. The produced composition was applied onto a silicon wafer using a spin coater, soft baked at 140 °C for 90 seconds, and then the target thickness of 10 μm was confirmed. After the exposure process was completed with a 248 nm light source, a baking process (PEB) was performed at 110 °C for 80 seconds, and then a development process was performed with 2.38% tetramethylammonium hydroxide to form a pattern. As a result, the sensitivity was confirmed at 96 mJ / cm 2 and a positive-tilt pattern with a line / space reference resolution of 2.5 μm and a Pattern Slope tilt angle of 82.7° was confirmed, and no residual scum was observed at the bottom of the pattern. Example 2 As a base resin, a phenol polymer resin with a weight average molecular weight of 15,000 (in Chemical Formula 7, R 8 is Chemical Formula a, R 9 is Chemical Formula c, and the copolymer molar ratios h, i, j are 7, 2, 1 respectively) 100 g, a pattern-bottom acid generation auxiliary monomer (Monomer) additive with a weight average molecular weight of 270 (in Chemical Formula 1, R 110.00 g of a structure with chemical formula d, 4 g of triphenylsulfonium nonaflate as a photoacid generator, and 0.6 g of triethanolamine as an acid diffusion inhibitor were used. As a solvent, a mixture of 114 g of propylene glycol monomethyl ether and 114 g of propylene glycol methyl ether acetate was used to produce a positive photoresist composition for KrF excimer laser. The produced composition was applied onto a silicon wafer using a spin coater, soft baked at 140 °C for 90 seconds, and then the target thickness of 10 μm was confirmed. After the exposure process was completed with a 248 nm light source, a baking process (PEB) was performed at 110 °C for 80 seconds, and then a development process was carried out with 2.38% tetramethylammonium hydroxide to form a pattern. As a result, the sensitivity was confirmed at 92 mJ / cm 2 and a positive-tilt pattern with a tilt angle of 84.3° for a line / space reference resolution of 2.2 μm was confirmed, and no residual scum was observed at the bottom of the pattern.

[0023] Example 3 As a base resin, a phenol polymer resin with a weight average molecular weight of 15,000 (in chemical formula 7, R 8 is chemical formula a, R 9 is chemical formula c, and the copolymer molar ratios h, i, j are 7, 2, 1 respectively) 100 g, a pattern bottom acid generation auxiliary monomer (Monomer) additive with a weight average molecular weight of 270 (in chemical formula 1, R 1The composition used was 15.00 g of a structure with chemical formula d, 4 g of triphenylsulfonium nonaflate as a photoacid generator, and 0.6 g of triethanolamine as an acid diffusion inhibitor. As the solvent, a mixture of 119 g of propylene glycol monomethyl ether and 119 g of propylene glycol methyl ether acetate was used to produce a positive photoresist composition for KrF excimer lasers. The produced composition was applied onto a silicon wafer using a spin coater, soft baked at 140 °C for 90 seconds, and then the target thickness of 10 μm was confirmed. After the exposure process was completed with a 248 nm light source, a baking treatment (PEB) was performed at 110 °C for 80 seconds, and then a development process was carried out with 2.38% tetramethylammonium hydroxide to form a pattern. As a result, the sensitivity was confirmed at 88 mJ / cm 2 and a positive-tilt pattern with a tilt angle of 86.5° for a line / space reference resolution of 2.0 μm was confirmed, and no residual scum was observed at the bottom of the pattern. Comparative Example 1 The experiment was carried out in the same manner as in Example 1, except that no acid generation assisting monomer additive was added to the bottom of the pattern and a mixture of 104 g of propylene glycol monomethyl ether and 104 g of propylene glycol methyl ether acetate was used as the solvent. Specifically, as the base resin, a phenol polymer resin with a weight average molecular weight of 15,000 (in Chemical Formula 7, R 8 is Chemical Formula a, R 9 is Chemical Formula c, and the copolymer molar ratios h, i, j are 7, 2, 1 respectively) 100 g, and an acid generation assisting monomer additive with a weight average molecular weight of 270 at the bottom of the pattern (in Chemical Formula 1, R 1A composition containing 100 g of a structure represented by Chemical Formula d, 4 g of triphenylsulfonium nonaflate as a photoacid generator, 0.6 g of triethanolamine as an acid diffusion inhibitor, and using a mixed solution of 104 g of propylene glycol monomethyl ether and 104 g of propylene glycol methyl ether acetate as a solvent was used to produce a positive photoresist composition for KrF excimer laser. The produced composition was applied onto a silicon wafer using a spin coater, soft baked at 140 °C for 90 seconds, and then the target thickness of 10 μm was confirmed. After the exposure process was completed with a 248 nm light source, a baking process (PEB) was performed at 110 °C for 80 seconds, and then a pattern was formed by developing with 2.38% tetramethylammonium hydroxide. As a result, the sensitivity was confirmed at 110 mJ / cm 2 and a positive-tilt pattern with a tilt angle of 74.5° for a 3.5 μm line / space reference resolution tilt pattern was confirmed, and residual scum was confirmed at the bottom of the pattern.

[0024] Comparative Example 2 An experiment was conducted in the same manner as in Comparative Example 1, except that 0.25 g of an acid generation assisting monomer additive was added to the bottom of the pattern. Specifically, as a base resin, a phenol polymer resin with a weight average molecular weight of 15,000 (in Chemical Formula 7, R 8 is Chemical Formula a, R 9 is Chemical Formula c, and the copolymer molar ratios h, i, j are 7, 2, 1 respectively) 100 g, and an acid generation assisting monomer additive with a weight average molecular weight of 270 at the bottom of the pattern (in Chemical Formula 1, R 1A positive photoresist composition for KrF excimer laser was prepared using 0.25 g of a structure having the chemical formula d, 4 g of triphenylsulfonium nonaflate as a photoacid generator, 0.6 g of triethanolamine as an acid diffusion inhibitor, and a mixed solution of 104 g of propylene glycol monomethyl ether and 104 g of propylene glycol methyl ether acetate as a solvent. The prepared composition was applied onto a silicon wafer using a spin coater, soft baked at 140 °C for 90 seconds, and then the target thickness of 10 μm was confirmed. After the exposure process was completed with a 248 nm light source, a baking treatment (PEB) was performed at 110 °C for 80 seconds, and then a development process was carried out with 2.38% tetramethylammonium hydroxide to form a pattern. As a result, the sensitivity was confirmed at 100 mJ / cm 2 A positive-tilt pattern with a tilt angle of 79.6° for a line / space reference resolution of 3.0 μm was confirmed, and residual scum was confirmed at the bottom of the pattern. Comparative Example 3 The experiment was carried out in the same manner as in Comparative Example 1, except that 30.00 g of an acid generation assisting monomer additive was added to the bottom of the pattern, and a mixed solution of 133 g of propylene glycol monomethyl ether and 133 g of propylene glycol methyl ether acetate was used as the solvent. Specifically, a phenol polymer resin having a weight average molecular weight of 15,000 as a base resin (in Chemical Formula 7, R 8 is Chemical Formula a, R 9 is Chemical Formula c, and the copolymerization molar ratios h, i, j are 7, 2, 1, respectively) 100 g, an acid generation assisting monomer (Monomer) additive having a weight average molecular weight of 270 at the bottom of the pattern (in Chemical Formula 1, R 1A composition containing 30.00 g of a structure with chemical formula d, 4 g of triphenylsulfonium nonaflate as a photoacid generator, and 0.6 g of triethanolamine as an acid diffusion inhibitor was used. As a solvent, a mixture of 133 g of propylene glycol monomethyl ether and 133 g of propylene glycol methyl ether acetate was used to produce a positive photoresist composition for KrF excimer laser. The produced composition was applied onto a silicon wafer using a spin coater, soft baked at 140 °C for 90 seconds, and then the target thickness of 10 μm was confirmed. After the exposure process was completed with a 248 nm light source, a baking treatment (PEB) was performed at 110 °C for 80 seconds, and then a development process was carried out with 2.38% tetramethylammonium hydroxide to form a pattern. As a result, the sensitivity was confirmed at 83 mJ / cm 2 and a positive-tilt pattern with a tilt angle of 87.3° for a line / space reference resolution of 1.8 μm was confirmed, and no residual scum was observed at the bottom of the pattern.

[0025] Measurement of properties The pattern profiles and properties of the chemically amplified positive photoresist compositions for improving resolution produced as in Examples 1 to 3 and Comparative Examples 1 to 3 were measured. Resolution and residual scum at the bottom of the pattern were measured using a length-measuring scanning electron microscope (CD-SEM) capable of observing the critical dimension of the pattern, and the minimum line width (resolution) was observed and confirmed as the L / S (Line, Space) standard. Also, the sensitivity was measured as the energy sensitivity at which the minimum line width (resolution) could be confirmed. The results measured in this way are shown in Table 1 below.

Table 1

[0026] In the cases of Comparative Example 1 and Comparative Example 2, as a result of confirmation using a length-measuring scanning electron microscope (CD-SEM), residual scum at the bottom of the pattern was confirmed, and thus they cannot be adopted. Also, Comparative Example 2 has an effect of improving resolution and vertical tilt patterns compared to Comparative Example 1, but the effect is very slight compared to Examples 1 to 3 and thus it cannot be adopted. In the case of Comparative Example 3, although it shows that sensitivity, resolution which is the minimum line width size, and vertical pattern tilt are improved compared to Comparative Example 1, it is confirmed that fatal pattern collapse occurs in some regions, so it cannot be adopted. As a result, when the acid generation assisting monomer additive at the bottom of the pattern of Chemical Formulas 1 to 3 is contained in an optimal content, it was confirmed that a photoresist composition for a KrF light source which improves the sensitivity and resolution of the formed pattern and shows a vertical profile compared to existing KrF positive photoresists can be provided. Simple modifications or changes of the present invention can be easily implemented by those having ordinary knowledge in the art, and all such modifications and changes should be regarded as belonging to the scope of the present invention.

Claims

1. A photoresist composition capable of being exposed with a light source having a wavelength of 248 nm contains, based on the total weight of the composition, 0.1 to 5% by weight of an acid generation assisting monomer additive which is one or more selected from the group represented by the following Chemical Formulas 1 to 3, 5 to 60% by weight of a phenolic polymer resin containing a hydroxyl group which is one or more selected from the group represented by the following Chemical Formulas 4 to 8, 0.05 to 10% by weight of a photoacid generator, and 0.01 to 5% by weight of an acid diffusion inhibitor, with the balance being a solvent, and is a chemically amplified positive photoresist composition for improving pattern profile and resolution. 【Chemical 1】 [Chemical Formula 2] 【Chemical Formula 3】 (In the above Chemical Formulas 1 to 3, R １ ~R ３ is a structure selected from the structures of the following Chemical Formulas A to E, and R represents a bonding site.) [Chemical Formula 4] [Chemical Formula 5] [Chemical Formula 6] 【Chemical Formula 7】 【Chemical Formula 8】 【Chemical Formula 9】 (In the above Chemical Formula 4, a and b are 1 to 10 in the molar ratio of repeating units forming a copolymer, and a + b = 10, R4 is any one structure selected from the structures of the following Chemical Formulas a to p, and R represents a bonding site.) 【Chemical 10】 【Chemical 11】 【Chemical Formula 12】 【Chemical 13】 【Chemical Formula 14】 【Chemical Formula 15】 【Chemical 16】 【Chemical 17】 【Chemical 18】 【Chemical 19】 【Chemical 20】 【Chemical formula 21】 【Chemical 22】 【Chemical 23】 【Chemical 24】 【Chemical 25】 【Chemical 26】 (In the above Chemical Formula 5, c and d are 1 to 10 in the molar ratio of repeating units forming a copolymer, and c + d = 10, R5 is the same as R4 and is any one structure selected from the structures of the above Chemical Formulas a to p, and R represents a bonding site.) 【Chemical 27】 (In the above Chemical Formula 6, e, f, and g are 1 to 10 in the molar ratio of repeating units forming a copolymer, and e + f + g = 10, R6 and R7 are the same as R4 and are any one structure selected from the structures of the above Chemical Formulas a to p, and R represents a bonding site.) 【Chemical Formula 28】 (In the above Chemical Formula 7, h, i, and j are 1 to 10 in the molar ratio of repeating units forming a copolymer, and h + i + j = 10, R8 and R9 are the same as R4 and are any one structure selected from the structures of the above Chemical Formulas a to p, and R represents a bonding site.) 【Chemical 29】 (In the above Chemical Formula 8, k, l, m, and n are 1 to 10 in the molar ratio of repeating units forming a copolymer, and k + l + m + n = 10, R10, R11, and R12 are the same as R4 and are any one structure selected from the structures of the above Chemical Formulas a to p, and R represents a bonding site.)

2. The photoacid generator is triphenylsulfonium triflate, triphenylsulfonium antimonate, diphenyliodonium triflate, diphenyliodonium antimonate, methoxydiphenyliodonium triflate, di-t-butyldiphenyliodonium triflate, 2,6-dinitrobenzyl sulfonate (2,6-dinitrobenzylsulfonate), pyrogallol trisalkylsulfonate, norbornene dicarboximide triflate, triphenylsulfonium nonaflate, diphenyliodonium nonaflate, methoxydiphenyliodonium nonaflate, di-t-butyldiphenyliodonium nonaflate, N-hydroxysuccinimide nonaflate, norbornene dicarboximide nonaflate, triphenylsulfonium perfluorooctanesulfonate, diphenyliodonium perfluorooctanesulfonate, methoxyphenyliodonium perfluorooctanesulfonate, di-t-butyldiphenyliodonium perfluorooctanesulfonate, N-hydroxysuccinimide perfluorooctanesulfonate, and norbornene dicarboximide perfluorooctanesulfonate, characterized in that it contains one or more selected from the group consisting of, the pattern profile according to claim 1 and a chemically amplified positive photoresist composition for improving resolution.,

3. The acid diffusion inhibitor contains one or more selected from the group consisting of dimethylamine, diethylamine, trimethylamine, triethylamine, tributylamine, dimethanolamine, diethanolamine, trimethanolamine, triethanolamine, and tributhanolamine. The pattern profile and the chemically amplified positive photoresist composition for resolution improvement according to claim 1 are characterized by this.

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