Composition for cleaning photoresist patterns

Abstract

The present invention provides a composition for cleaning photoresist patterns, comprising a monoalcohol compound, an ester compound of a specific structure, and water. [Effects] The photoresist pattern cleaning composition according to the present invention can prevent pattern deformation and damage during cleaning of fine patterns, exhibits excellent cleaning power, and minimizes the generation of impurities originating from the composition itself.

Description

[Technical Field]

[0001] The present invention relates to a composition for cleaning photoresist patterns, and more particularly to a composition for cleaning photoresist patterns that can prevent pattern deformation and damage when cleaning fine patterns having a high aspect ratio, exhibit excellent cleaning power, and minimize the generation of impurities originating from the composition itself. [Background technology]

[0002] In photolithography, a process used to form fine structures in semiconductor manufacturing, the aspect ratio of a pattern increases as the line width of the pattern decreases. When the exposed area is washed and dried with deionized water after the development process, pattern collapse can occur due to capillary force exerted by water droplets pulling on the fine pattern during the drying process. To address this problem, a method is employed that reduces pattern defects during the washing and drying processes by using a washing solution with a lower surface tension after treatment with the developer.

[0003] Furthermore, it has been reported that removing development residue that could not be completely removed during the post-development washing stage improves the resolution of fine patterns and enhances the overall process margin of the photolithography process. Therefore, the composition used in the washing stage must have a suitable cleaning power to remove residue from the bottom surface of the photoresist pattern.

[0004] However, approaching the problem from this perspective can lead to the dissolution of photoresist patterns made of organic compounds, especially polymer compounds, causing the patterns themselves to deform. Therefore, it is important that the cleaning composition does not damage the photoresist patterns.

[0005] Korean Published Patent No. 10-2017-0075438 discloses a photolithography rinse solution containing a surfactant comprising a compound having a branched structure including a main chain containing a hydrophobic group and a plurality of side chains branching from the main chain and each having at least one hydrophilic functional group, as an example of a cleaning composition for preventing pattern collapse, and deionized water.

[0006] However, with the aforementioned rinsing solution, it is difficult to prevent the pattern from collapsing when cleaning fine patterns with a high aspect ratio, and there are problems such as the cleaned pattern being damaged or the rinsing solution components remaining and generating a large amount of impurities. [Overview of the project] [Problems that the invention aims to solve]

[0007] One objective of the present invention is to provide a photoresist pattern cleaning composition that can prevent pattern deformation and damage during cleaning of fine patterns having a high aspect ratio, exhibits excellent cleaning power, and minimizes the generation of impurities originating from the composition itself. [Means for solving the problem]

[0008] On the other hand, the present invention provides a composition for cleaning photoresist patterns, comprising a monoalcohol compound, a compound represented by the following chemical formula 1, and water.

[0009] [Chemical formula 1] [ka] In the above formula, R 1 is a hydrogen atom or a C1-C5 alkyl group, R 2 is a C2-C5 alkyl group, R 1 and R 2 The total number of carbon atoms in the compound is 6 or less.

[0010] In one embodiment of the present invention, the monoalcohol compound may be a C2-C5 monoalcohol compound.

[0011] In one embodiment of the present invention, the monoalcohol compound may have an octanol / water partition coefficient (Log P) calculated by the following Mathematical Formula 1 of -0.5 to 1.5. [Mathematical Formula 1] K ow =C o / C w (C o : Concentration of the alcohol compound in octanol, C w : Concentration of the alcohol compound in water) Log P (partition coefficient) = Log(K ow )

[0012] In one embodiment of the present invention, the monoalcohol compound may be one or more selected from the group consisting of ethanol, 1-propanol, 1-pentanol, and 1-methoxy-propanol.

[0013] In one embodiment of the present invention, the monoalcohol compound may be contained in an amount of 0.1 to 20% by weight based on 100% by weight of the total composition.

[0014] In one embodiment of the present invention, the compound represented by Chemical Formula 1 may be one or more selected from the group consisting of ethyl propionate, propyl propionate, butyl propionate, and propionic acid.

[0015] In one embodiment of the present invention, the compound represented by Chemical Formula 1 may be contained in an amount of 0.001 to 0.5% by weight based on 100% by weight of the total composition.

[0016] In one embodiment of the present invention, the water may be deionized water.

[0017] The composition for cleaning a photoresist pattern according to an embodiment of the present invention may not contain an alkali compound and a fluoride.

Advantages of the Invention

[0018] The composition for cleaning a photoresist pattern according to the present invention can prevent pattern collapse and damage during the cleaning of a fine pattern having a high aspect ratio, exhibits excellent detergency, and can minimize the generation of impurities derived from the composition itself.

Embodiments for Carrying Out the Invention

[0019] Hereinafter, the present invention will be described in more detail.

[0020] One embodiment of the present invention relates to a composition for cleaning a photoresist pattern, which contains a monoalcohol compound, an ester compound having a specific structure, and water.

[0021] The composition for cleaning a photoresist pattern according to the present invention contains a monoalcohol compound and an ester compound having a specific structure, can prevent pattern collapse and damage during the cleaning of a fine pattern having a high aspect ratio, can remove development residues during the cleaning process, and can minimize the generation of impurities derived from the composition itself.

[0022] Hereinafter, the components of the composition for cleaning a photoresist pattern according to an embodiment of the present invention will be described in more detail.

[0023] In one embodiment of the present invention, the composition for cleaning a photoresist pattern contains a monoalcohol compound.

[0024] The photoresist pattern cleaning composition according to the present invention contains the monoalcohol compound, which allows the monoalcohol to dissolve in water and weaken the hydrogen bonds between water molecules. This reduces the surface tension of water and the contact angle at the interface, suppressing phenomena such as the photoresist pattern collapsing or being damaged during cleaning of fine patterns.

[0025] The term "monoalcohol compounds" as used herein refers to alcohol compounds having a saturated hydrocarbon group composed of 1 to 12 carbon atoms and one hydroxyl group.

[0026] In one embodiment of the present invention, the monoalcohol compound may be a C2-C5 monoalcohol compound.

[0027] In one embodiment of the present invention, the monoalcohol compound may have an octanol / water partition coefficient (Log P) calculated by the following mathematical formula 1, which is between -0.5 and 1.5. [Mathematical formula 1] K ow =C o / C w (C o :Concentration of alcohol compounds in octanol, C w (Concentration of alcohol compounds in water) Log P (distribution coefficient) = Log(K) ow )

[0028] The aforementioned partition coefficient is the concentration ratio of a compound in a mixture of two unmixed solvents at equilibrium. This allows us to predict the water dispersibility of the compound to be dissolved; a high partition coefficient indicates low water dispersibility, while a low partition coefficient indicates high water dispersibility.

[0029] If the distribution coefficient is less than -0.5, it is difficult to expect an effect in preventing pattern collapse during cleaning, and if it exceeds 1.5, the photoresist pattern may be damaged by cleaning, or a large amount of impurities may be generated from the composition itself.

[0030] Examples of monoalcohol compounds with a partition coefficient of -0.5 to 1.5 include, but are not limited to, ethanol, 1-propanol, 1-pentanol, and 1-methoxypropanol.

[0031] In one embodiment of the present invention, the monoalcohol compound may be present in an amount of 0.1 to 20% by weight, preferably 0.5 to 10% by weight, based on 100% by weight of the total composition. If the content of the monoalcohol compound is less than 0.1% by weight, the effect of preventing pattern collapse during cleaning is poor, and if it exceeds 20% by weight, the photoresist pattern may be damaged or the pattern may dissolve, resulting in a low residual film rate, making it difficult to obtain a pattern with a high aspect ratio.

[0032] In one embodiment of the present invention, the photoresist pattern cleaning composition comprises a compound represented by the following chemical formula 1. [Chemical formula 1] [ka] In the above formula, R 1 is a hydrogen atom or a C1-C5 alkyl group, R 2 is a C2-C5 alkyl group, R 1 and R 2 The total number of carbon atoms in the compound is 6 or less.

[0033] The photoresist pattern cleaning composition according to the present invention, by using the compound represented by chemical formula 1 together with a monoalcohol compound, can prevent the pattern from collapsing by lowering the contact angle on the surface of the fine pattern during cleaning after the photoresist development process, and can minimize damage to the photoresist pattern.

[0034] As used herein, C1-C5 alkyl groups refer to linear or branched monovalent hydrocarbons consisting of 1 to 5 carbon atoms, and include, but are not limited to, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, and n-pentyl.

[0035] As used herein, C2-C5 alkyl groups refer to linear or branched monovalent hydrocarbons consisting of 2 to 5 carbon atoms, and include, but are not limited to, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, and n-pentyl.

[0036] The compound represented by chemical formula 1 may be one or more selected from the group consisting of ethyl propionate, propyl propionate, butyl propionate, and propionic acid, but is not limited to these.

[0037] In one embodiment of the present invention, the compound represented by chemical formula 1 may be included in an amount of 0.001 to 0.5% by weight, preferably 0.005 to 0.3% by weight, based on 100% by weight of the total composition. If the content is less than 0.001% by weight, it is difficult to expect an effect in preventing pattern collapse, and if it exceeds 0.5% by weight, the photoresist pattern may be damaged or dissolved, resulting in a decrease in film thickness.

[0038] A photoresist pattern cleaning composition according to one embodiment of the present invention contains water as a solvent, in which case the water may be included as the remainder of the composition other than the other components.

[0039] In one embodiment of the present invention, the water may be deionized water (DIW). When deionized water is used, process costs are reduced and handling and wastewater treatment are easier.

[0040] Furthermore, as mentioned above, since the water is included as a remainder, the water content may change if the content of the constituent components in the photoresist pattern cleaning composition changes.

[0041] Furthermore, in order to further improve the effectiveness of the photoresist pattern cleaning composition of the present invention, in addition to the components described above, it may further contain conventional additives.

[0042] The photoresist pattern cleaning composition according to one embodiment of the present invention may be free of alkali compounds and fluorides in order to minimize damage to the photoresist pattern.

[0043] The aforementioned alkali compound may dissolve the photoresist pattern made of polymer components, causing deformation and peeling of the pattern shape, and the aforementioned fluoride may remain after washing, increasing the generation of impurities.

[0044] The photoresist pattern cleaning composition according to the present invention may be suitably used in the cleaning process after development of the photoresist pattern, and may be particularly suitably used as a rinsing solution.

[0045] The present invention will be described in more detail below with reference to examples, comparative examples, and experimental examples. It should be noted that these examples, comparative examples, and experimental examples are merely for illustrative purposes, and it will be obvious to those skilled in the art that the scope of the present invention is not limited thereto.

[0046] Examples 1-22 and Comparative Examples 1-10: Production of compositions for cleaning photoresist patterns As shown in Tables 1 and 2 below, each component was mixed to produce a composition for cleaning photoresist patterns (unit: weight %).

[0047] [Table 1]

[0048] [Table 2]

[0049] Experimental Example 1: After forming a photoresist pattern according to the method described below, the pattern collapse and pattern damage were evaluated using the photoresist pattern cleaning compositions of the above examples and comparative examples, and the results are shown in Tables 3 and 4 below.

[0050] <Method for forming and cleaning photoresist patterns> A back-side anti-reflective coating (DUV42P-6, manufactured by Nissan Chemical Industries, Ltd.) was spin-coated onto a silicon substrate, and then heated at 215°C for 90 seconds to form a 600Å thick film. A PHS-type photosensitive material (KTF-5664, manufactured by Toyo Finechem Co., Ltd.) was spin-coated on top of this to produce a photoresist thin film, which was then soft-baked in a 100°C oven for 60 seconds. After soft-baking, the film was exposed using a scanner equipped with a KrF laser, and then post-baked in a 110°C oven for another 60 seconds.

[0051] After post-baking was complete, the wafers were developed by immersion in a 2.38 wt% tetramethylammonium hydroxide (TMAH) aqueous solution for 60 seconds, and then the development residue was removed using deionized water. Then, 30 mL of the cleaning composition prepared in the examples and comparative examples was applied to the surface of the silicon wafer for 10 seconds, and the wafer was dried by high-speed spinning to obtain a 180 nm L / S pattern.

[0052] (1) Pattern Collapse The degree to which the 180nm L / S pattern collapsed was observed using a CD-SEM (Hitachi Corporation) and evaluated according to the following evaluation criteria. <Evaluation Criteria> ○: No pattern failures occur. △: The tipping phenomenon occurs only in the edge pattern. ×: The pattern of the edges and the center will fall over.

[0053] (2) Degree of damage to the photoresist pattern Using an FE-SEM (Hitachi Corporation), the difference in thickness of the photoresist pattern before and after treatment with the photoresist pattern cleaning composition was measured to confirm the degree of thickness reduction of the photoresist pattern, and the degree of damage to the photoresist pattern was evaluated according to the evaluation criteria below. A smaller difference in the thickness of the photoresist pattern indicates less damage to the photoresist pattern. <Evaluation Criteria> ○: Photoresist thickness reduction of 50 Å or less △: Photoresist thickness reduction greater than 50 Å and less than 100 Å ×: Photoresist thickness reduction exceeds 100 Å

[0054] Experimental Example 2: Degree of residual particle generation The photoresist pattern cleaning compositions of the examples and comparative examples were filtered through a 0.01 μm filter, and then measured using a liquid particle counter manufactured by Rion Co., Ltd. <ks-18f>After allowing the mixture to flow for approximately 30 minutes and then leaving it to stand, the number of 100 nm size particles was measured. The results were evaluated according to the following evaluation criteria and are shown in Tables 3 and 4 below. <Evaluation Criteria> ○: Less than 100 △: 100 or more but less than 300 ×: 300 or more pieces

[0055] [Table 3]

[0056] [Table 4]

[0057] As shown in Table 3 above, the photoresist pattern cleaning compositions of Examples 1 to 22, which include monoalcohol compounds and ester compounds of specific structures, were found to suppress pattern collapse during cleaning of fine patterns, prevent pattern damage, and suppress the generation of residual particles due to the components of the composition.

[0058] In contrast, as shown in Table 4, the photoresist pattern cleaning compositions of Comparative Examples 1 to 10 failed to prevent the patterns from collapsing during cleaning of fine patterns, or caused damage to the patterns, or generated a large amount of residual particles.

[0059] Although specific parts of the present invention have been described in detail above, it is clear to any person with ordinary skill in the art to which the present invention belongs that such specific descriptions are merely preferred examples and do not limit the scope of the present invention. A person with ordinary skill in the art to which the present invention belongs will be able to make various applications and modifications within the scope of the present invention based on the above content.

[0060] Therefore, the substantial scope of the present invention can be defined by the claims and their equivalents.

Claims

1. A composition for cleaning photoresist patterns, comprising a monoalcohol compound, a compound represented by the following chemical formula 1, and water. [Chemical formula 1] 【Chemistry 1】 In the above formula, R １ is a hydrogen atom or C １ -C ５ It is an alkyl group, R ２ C ２ -C ５ It is an alkyl group, R １ and R ２ The total number of carbon atoms contained in it is 6 or less.

2. The monoalcohol compound is C ２ -C ５ The composition for cleaning a photoresist pattern according to claim 1, which is a monoalcohol compound of

3. The photoresist pattern cleaning composition according to claim 1, wherein the monoalcohol compound has an octanol / water partition coefficient (Log P) calculated by the following mathematical formula 1, which is between -0.5 and 1.

5. [Mathematical formula 1] K ｏｗ =C ｏ / C ｗ (C ｏ : Concentration of alcohol compounds in octanol, C ｗ (Concentration of alcohol compounds in water) Log P (distribution coefficient) = Log (K) ｏｗ )

4. The photoresist pattern cleaning composition according to claim 1, wherein the monoalcohol compound is one or more selected from the group consisting of ethanol, 1-propanol, 1-pentanol, and 1-methoxypropanol.

5. The photoresist pattern cleaning composition according to claim 1, wherein the monoalcohol compound is contained in an amount of 0.1 to 20% by weight based on 100% by weight of the total composition.

6. The photoresist pattern cleaning composition according to claim 1, wherein the compound represented by chemical formula 1 is one or more selected from the group consisting of ethyl propionate, propyl propionate, butyl propionate, and propionic acid.

7. The photoresist pattern cleaning composition according to claim 1, wherein the compound represented by chemical formula 1 is contained in an amount of 0.001 to 0.5% by weight based on 100% by weight of the total composition.

8. The photoresist pattern cleaning composition according to claim 1, wherein the water is deionized water.

9. A photoresist pattern cleaning composition according to claim 1, which does not contain alkali compounds or fluorides.

Images