JP2008293014A - Covering material for photoresist pattern and fine pattern forming method using the covering material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a covering material for a photoresist pattern, and to provide a fine pattern forming method using this covering material. <P>SOLUTION: The covering material 10B for the photoresist pattern comprises an additive being at least one selected from a group composed of a water soluble polymer and a compound expressed by the formula [1] (in the formula [1], X and Y are each independently one selected from a group composed of N, O and S; and R<SB>1</SB>or R<SB>8</SB>is each independently one selected from a group composed of an alkyl group and -H having the carbon number of 1-5) or the formula [2] (in the formula [2], Z and W are each independently one selected from a group composed of N, O and S; and R<SB>11</SB>or R<SB>17</SB>is each independently one selected from a group composed of a 1-5C alkyl group and -H.). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a coating forming material. In particular, the present invention relates to a photoresist pattern coating material and a fine pattern forming method using the same.

  A number of patterning processes are used in the manufacture of electronic components such as semiconductor devices and LCDs. In this patterning process, a technique is used in which a photoresist pattern is formed on a substrate and various fine patterns are formed on the substrate using the photoresist pattern as a mask pattern. As electronic parts have become smaller and lighter in recent years, research to further reduce the fine pattern is underway.

  In general, the minimum size of the photoresist pattern is determined by the limit resolution of the exposure apparatus. As a technique for forming a fine pattern having a size smaller than the limit resolution of an exposure apparatus, there is a method in which a photoresist pattern is heat treated to flow. Here, the flow due to the heat treatment is affected by the volume of the photoresist pattern. That is, when a plurality of photoresist patterns having different sizes are formed on the substrate, it is very difficult to expand and reduce the size and form of the fine pattern at a uniform rate. For example, there may be a problem that a gap region between patterns is embedded due to overflow.

  As another technique for forming a fine pattern having a size smaller than the limit resolution of the exposure apparatus, there is a technique for forming a coating layer on the surface of a photoresist pattern using a coating forming material.

  For example, for a method for forming a fine pattern using a coating forming material, Patent Document 1 discloses “Coating material for pattern enhancement and method of forming fine pattern with the method”. In the name of Shinbori.

According to Shinbori, a coating-forming material comprising a water-soluble polymer and a water-soluble cross-linking agent is provided. Moreover, the fine pattern formation method using this coating forming material is provided.
US Patent Application Publication No. 2005/0123851

  The coating forming material used for forming the fine pattern is required to easily remove the residual slurry after the reaction without dissolving the photoresist pattern. However, in the case of using a conventional film-forming material composed of a water-soluble polymer and a water-soluble crosslinking agent, the solubility of the film-forming material in water is insufficient, and the gap region between the photoresist pattern is a polymer. There is a problem of being embedded by the slurry. That is, residual slurry after the reaction of the coating forming material remains on the photoresist pattern, causing defects such as clogging of contact holes and micro-bridging between patterns.

  Therefore, a technical problem to be solved by the present invention is to provide a coating material for a photoresist pattern in which removal of a slurry residue after reaction is easy.

  Another technical problem to be solved by the present invention is to provide a fine pattern forming method using a coating material for a photoresist pattern.

  The present inventors have intensively studied to solve the above problems. As a result, it has been found that the above-mentioned problems can be solved by using a photoresist pattern coating material containing a water-soluble polymer and a specific additive, and the present invention has been completed.

  In order to solve the above technical problem, the present invention provides a coating material for a photoresist pattern.

  According to an embodiment of the present invention, the dressing includes a water-soluble polymer and specific additives.

  According to another embodiment of the present invention, the dressing includes a water-soluble polymer, an additive, a cross-linking agent, and water.

  The present invention also provides a fine pattern forming method using a photoresist pattern coating material.

  According to an embodiment of the present invention, the method for forming a fine pattern includes preparing a coating material. In the present embodiment, the coating material is a mixture containing a water-soluble polymer and an additive.

  The covering material may further be mixed with a crosslinking agent and water. In this embodiment, the coating material is applied on a substrate having a photoresist pattern. Next, the coating material and the photoresist pattern are subjected to a crosslinking reaction to form a coating pattern on the photoresist pattern.

  In some embodiments of the present invention, after the coating pattern is formed, the unreacted coating material can be removed to expose the substrate between the photoresist patterns. Next, the exposed substrate can be etched using the covering pattern and the photoresist pattern as an etching mask.

  In another embodiment of the present invention, a hard mask film may be formed on the substrate before forming the photoresist pattern. The hard mask film may be formed of a pad oxide film covering the substrate and a mask nitride film covering the pad oxide film.

  In still another embodiment of the present invention, after forming the coating pattern, the unreacted coating material may be removed to expose the hard mask film between the photoresist patterns.

  In still another embodiment of the present invention, the exposed hard mask film may be etched using the coating pattern and the photoresist pattern as an etching mask to form a hard mask pattern.

  In still another embodiment of the present invention, the substrate can be etched using the hard mask pattern as an etching mask.

  According to the present invention, the solubility of a photoresist pattern coating material in water can be significantly increased as compared with the conventional one.

  Further, according to the present invention, a fine pattern such as a contact hole, a trench, and / or a groove can be formed in a desired size and form.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below, and can be embodied in other forms. Accordingly, the embodiments disclosed below are provided to complete the disclosure of the present invention and to fully convey the spirit of the present invention to those skilled in the art.

  For convenience of explanation, the thickness of layers and regions is exaggerated in the drawings, and the illustrated form may be different from the actual one.

  Also, when a layer is described as being “on” another layer or substrate, this is not limited to being formed “directly” directly on another layer or substrate, but between them. Including the case where the third layer is interposed. Like reference numerals refer to like elements throughout the specification.

  The photoresist pattern coating material according to an exemplary embodiment of the present invention is a mixture containing a water-soluble polymer and an additive.

  The additive used in the present invention is at least one selected from the group consisting of compounds represented by the following chemical formula 1 or chemical formula 2.

[Wherein X and Y are each independently any one selected from the group consisting of N, O and S, and R ₁ to R ₈ are each independently an alkyl group having 1 to 5 carbon atoms and Any one selected from the group consisting of -H. ]

[Wherein, Z and W are each independently any one selected from the group consisting of N, O and S, and R ₁₁ to R ₁₇ are each independently an alkyl group having 1 to 5 carbon atoms and 1 represents one selected from the group consisting of -H. ]
Here, specific examples of the alkyl group having 1 to 5 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, and tert-butyl group. , N-pentyl group, isopentyl group, neopentyl group, 2-methylbutyl group, and the like. Among these, a methyl group, an ethyl group, an n-propyl group, and an isopropyl group are preferable.

  Examples of additives that can be used in the present invention include 2- (methylamino) ethanol, 2- (dimethylamino) ethanol, 2-methoxy-N-methylethanamine, 2-methoxy-N, N-dimethylethanamine. 2-ethoxy-N-methylethanamine, 2-ethoxy-N, N-dimethylethanamine, N-methyl-2-propoxyethanamine, N, N-dimethyl-2-propoxyethanamine, 2-isopropoxy- N-methylethanamine, 2-isopropoxy-N, N-dimethylethanamine, N-ethyl-2-isopropoxyethanamine, 2- (ethylamino) ethanol, N-ethyl-2-methoxyethanamine, 2- Ethoxy-N-ethylethanamine, N, N-diethyl-2-isopropoxyethanamine, N, N-di Tyl-2-methoxyethanamine, 2-ethoxy-N, N-diethylethanamine, 2- (diethylamino) ethanol, 2-isopropoxyethanamine, 2-methoxyethanamine, 2-ethoxyethanamine, 2-aminoethanol 2-aminoethanethiol, 2- (methylthio) ethanamine, 2- (ethylthio) ethanamine, 2- (isopropylthio) ethanamine, 2- (isopropylthio) ethanamine, 2- (methylamino) ethanthiol, N-methyl- 2- (methylthio) methanamine, 2- (ethylthio) -N-methylethanamine, 2- (isopropylthio) -N-methylethanamine, 2- (isopropylthio) -N-methylethanamine, 2- (ethylamino) ) Ethanethiol, N-ethyl-2- (meth) Thio) ethanamine, N-ethyl-2- (ethylthio) ethanamine, N-ethyl-2- (isopropylthio) ethanamine, N-ethyl-2- (isopropylthio) ethanamine, 2- (diethylamino) ethanthiol, N, N -Diethyl-2- (methylthio) ethanamine, N, N-diethyl-2- (ethylthio) ethanamine, N, N-diethyl-2- (isopropylthio) ethanamine, tetramethylenediamine, and N, N-diethyl-2- It can be at least one selected from the group consisting of (isopropylthio) ethanamine.

  Such an additive can significantly increase the solubility of the photoresist pattern coating material in water compared to the conventional one.

  As the water-soluble polymer, for example, a polymer having a repeating structural unit represented by the following chemical formula 3 can be used.

[Wherein R ₂₁ is an acyl group having 2 to 6 carbon atoms, and R ₂₂ is an alkyl group having 1 to 3 carbon atoms (in this case, R ₂₂ forms an acetal in the polymer molecule). K is an integer of 1 to 150, and m and n are each independently an integer of 1 to 120. ]
In the repeating structural unit represented by Chemical Formula 3, k is 1 to 100, m is 1 to 100, and n is an integer of 1 to 100. Moreover, as a ratio of k, m, n, k / (k + m + n) is preferably 1 to 98, m / (k + m + n) is preferably 1 to 98, and n / (k + m + n) is preferably 1 to 98. 98.

  The water-soluble polymer used in the present invention may be composed of a plurality of repeating structural units having different (k, m, n), and in this case, the arrangement of each repeating structural unit is random or block-like. There may be. The terminal of the water-soluble polymer is not particularly limited. The molecular weight of the water-soluble polymer is preferably 5000 to 15000.

In addition, R ₂₁ and R ₂₂ in Chemical Formula 3 may all be the same or different from each other.

  Examples of the acyl group having 2 to 6 carbon atoms include acetyl group, ethylcarbonyl group, n-propylcarbonyl group, isopropylcarbonyl group, n-butylcarbonyl group, isobutylcarbonyl group, sec-butylcarbonyl group, tert-butylcarbonyl group, Examples include n-pentylcarbonyl group, isopentylcarbonyl group, neopentylcarbonyl group, 2-methylbutylcarbonyl group and the like.

In the above chemical formula 3, R ₂₁ is preferably an acetyl group. In addition, R ₂₂ preferably forms an acetal (a cyclic structure having an acetal group —OR ₂₂ O—, see the following formula) in cooperation with neighboring R ₂₂ .

[Wherein, R is —H, R ₂₁ , or R ₂₂ . ]
If R ₂₂ as described above to form an acetal, it is preferred that R ₂₂ in the acetal structure is a ethylidene group, isopropylidene group, diethylmethylene group.

  In an embodiment of the present invention, the water-soluble polymer represented by Formula 3 may be polyhydroxyacrylate (poly (hydroxyl) acrylate).

  The photoresist pattern coating material according to the embodiment of the present invention can significantly increase the solubility in water as compared with the conventional one. The effect of improving the solubility in water is presumed to be exhibited by the following mechanism.

  The water-soluble polymer contained in the photoresist pattern coating material preferably has high solubility in water. For example, it has a hydroxyl group (-OH) as represented by the following chemical formula 4.

  Here, the hydroxyl group (—OH) can form an intramolecular hydrogen bonding (Hb) as represented by the following chemical formula 5. Such an intramolecular hydrogen bond (Hb) can function as a crystallization point. For this reason, intramolecular hydrogen bonding (Hb) may hinder the dissolution of the water-soluble polymer in water. In this case, it is considered that a gap region between the photoresist patterns is filled with the polymer slurry. In addition, the polymer slurry may cause defects such as clogging of contact holes.

  The coating material for a photoresist pattern according to the embodiment of the present invention contains the above-mentioned additives in addition to the water-soluble polymer. The additive used in the present invention has polarity because it contains N, O, and S atoms (heteroatoms), and thereby serves to weaken the intramolecular hydrogen bond (Hb) of the water-soluble polymer. Therefore, the solubility of the photoresist pattern coating material in water can be significantly increased as compared with the conventional one. When the photoresist pattern coating material of the present invention is used, the polymer slurry remains after the reaction. It is considered that removal of the slurry residue after the reaction becomes easy because the solubility of the product in water is high.

  For example, a preferred photoresist pattern coating material of the present invention is represented by the following chemical formula 6. In the photoresist pattern coating material according to the embodiment of the present invention, X and Y or Z and W N, O, and S atoms (heteroatoms) in the additive form intramolecular hydrogen bonds in the water-soluble polymer. Acts on hydroxyl groups. As a result, the intramolecular hydrogen bond (Hb) is weakened, and the solubility of the photoresist pattern coating material in water can be significantly increased compared to the conventional case.

  The mechanism for improving the solubility of the photoresist pattern coating material of the present invention in water has been described above, but the mechanism of the present invention is not limited to the above.

  The content of the additive contained in the coating material for the photoresist pattern is not particularly limited as long as the object of the present invention is not impaired. However, the content of the additive is 0. 0% with respect to the total amount of the coating material for the photoresist pattern. It is preferable that the amount is not less than 05% by weight and less than 0.4% by weight.

  The content of the water-soluble polymer contained in the photoresist pattern coating material is not particularly limited as long as the object of the present invention is not impaired, but the content of the water-soluble polymer is based on the total amount of the photoresist pattern coating material. It is preferable that it is 99.6 weight% or more and less than 99.95 weight%.

  The photoresist pattern coating material according to another embodiment of the present invention further includes a crosslinking agent and water in addition to the water-soluble polymer and the additive. That is, the photoresist pattern coating material according to the present embodiment includes a water-soluble polymer, an additive, a crosslinking agent, and water.

  In the present embodiment, as the water-soluble polymer, the polymer represented by the above-described chemical formula 3 can be preferably used similarly. Further, as the additive, a compound that is at least one selected from the group consisting of the compounds represented by Chemical Formula 1 or Chemical Formula 2 described above can be preferably used.

  The crosslinking agent is preferably a water-soluble material that causes a crosslinking reaction by heat or acid. Specifically, the crosslinking agent is preferably an amino crosslinking agent. The amino crosslinking agent is preferably at least one selected from the group consisting of melamine derivatives, urea derivatives, and uril derivatives. A crosslinking agent may be used individually by 1 type, and 2 or more types may be mixed and used for it.

  The urea derivative is not particularly limited, and examples thereof include urea, alkoxymethylene urea, N-alkoxymethylene urea, ethylene urea, ethylene urea carboxylic acid, and derivatives thereof. Although it does not restrict | limit especially as a melamine derivative, Alkoxymethyl melamine, those derivatives, etc. are mentioned. Although it does not restrict | limit especially as a uril derivative, A benzoguanamine, glycoluril, those derivatives, etc. are mentioned.

  When the photoresist pattern coating material contains a water-soluble polymer, an additive, a crosslinking agent, and water, the content of the additive is not particularly limited as long as it does not impair the object of the present invention, but the content of the additive Is preferably 0.05% by weight or more and less than 0.4% by weight based on the total amount of the coating material for a photoresist pattern.

  Further, the content of the water-soluble polymer contained in the coating material for photoresist pattern is not particularly limited as long as it does not impair the purpose of the present invention, but the content of the water-soluble polymer is the total amount of the coating material for photoresist pattern. On the other hand, it is preferably 3% by weight or more and less than 10% by weight.

  The content of the crosslinking agent contained in the coating material for a photoresist pattern is not particularly limited as long as the object of the present invention is not impaired. However, the content of the crosslinking agent is 0. 0% relative to the total amount of the coating material for a photoresist pattern. It is preferable that the amount is not less than 05% by weight and less than 0.1% by weight.

  The water content contained in the photoresist pattern coating material is not particularly limited as long as the object of the present invention is not impaired. However, the water content is 89.5% by weight based on the total amount of the photoresist pattern coating material. % Or more and less than 96.9% by weight.

  Hereinafter, a fine pattern forming method using a photoresist pattern coating material according to a preferred embodiment of the present invention will be described with reference to FIGS. 1 to 6 are cross-sectional views illustrating each step in a fine pattern forming method using a photoresist pattern coating material according to an embodiment of the present invention.

  As shown in FIG. 1, first, a photoresist pattern coating material 10 containing a water-soluble polymer 11 and an additive 13 is prepared. The photoresist pattern coating material 10 may be any one of the photoresist pattern coating materials according to the above-described embodiments. That is, the photoresist pattern coating material 10 can be produced by mixing the water-soluble polymer 11 and the additive 13. Alternatively, the photoresist pattern coating material 10 may be manufactured by mixing the water-soluble polymer 11, the additive 13, the crosslinking agent 15, and the water 17. In addition, the water-soluble polymer 11, the additive 13, the crosslinking agent 15, and the water 17 can use the same thing as what was demonstrated by said embodiment. Hereinafter, the photoresist pattern coating material 10 is also simply referred to as a coating material 10.

  As shown in FIG. 2, a hard mask film 25 is formed on the substrate 21. As the substrate 21, a semiconductor substrate such as a silicon wafer can be used. The hard mask film 25 can be formed of a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a combination thereof. A plurality of different material films such as an interlayer insulating film and / or a conductive film are further formed on the substrate 21, but the description thereof is omitted.

  For example, the hard mask film 25 is preferably formed by sequentially laminating a pad oxide film 23 and a mask nitride film 24. Specifically, a pad oxide film 23 made of a silicon oxide film can be formed on the substrate 21 by a thermal oxidation method. A mask nitride film 24 made of a silicon nitride film can be formed on the pad oxide film 23 by chemical vapor deposition (CVD). The hard mask film 25 can be omitted.

  Subsequently, a photoresist pattern 27 having a first opening 27 </ b> H can be formed on the hard mask film 25. The first opening 27H can be a gap region formed between adjacent photoresist patterns 27. Such first opening 27H may be, for example, a contact hole, a trench, and / or a groove. In the first opening 27H, the upper surface of the hard mask film 25 is partially exposed.

  The photoresist pattern 27 can be formed using a known photolithography process. In this case, the minimum size of the photoresist pattern 27 and the first opening 27H is determined by the limit resolution of the photolithography process.

  As shown in FIG. 3, the coating material 10 can be applied on the substrate 21 having the photoresist pattern 27. The coating material 10 can be applied using equipment such as a spin coater. Specifically, the covering material 10 is applied on the first opening 27 </ b> H and the photoresist pattern 27. Then, the applied covering material 10 can be first baked at a low temperature of 50 to 100 ° C. In this case, the moisture in the coating material 10 applied as described above is almost evaporated, and the coating layer 10 </ b> A can be formed on the substrate 21. Note that the first baking can be omitted.

  The covering layer 10 </ b> A is preferably formed so as to fill the first opening 27 </ b> H and cover the photoresist pattern 27. The covering layer 10 </ b> A is preferably in contact with the sidewall and the upper surface of the photoresist pattern 27.

  As shown in FIG. 4, the coating layer 10 </ b> A and the photoresist pattern 27 can be crosslinked 10 </ b> R by a crosslinking reaction to form a coating pattern 10 </ b> B that covers the surface of the photoresist pattern 27. The cross-linking 10R of the coating layer 10A and the photoresist pattern 27 can be performed by a second bake process performed at a temperature of 80 to 250 ° C. Thus, the coating pattern 10B can be formed by a crosslinking reaction between the coating layer 10A and the photoresist pattern 27.

  The covering pattern 10 </ b> B can be formed along the surface of the photoresist pattern 27. In this case, the coating layer 10A may partially remain in the first opening 27H. Further, the coating layer 10 </ b> A may partially remain on the photoresist pattern 27.

  As shown in FIG. 5, the substrate 21 having the coating pattern 10B can be washed to remove the coating layer 10A. Washing can be performed using water such as DI water (deionized water) or distilled water. As a result, the coating pattern 10 </ b> B can remain on the sidewall and the upper surface of the photoresist pattern 27.

  Thereby, the first opening 27H is reduced and the second opening 31H is formed. The size of the second opening 31H can be adjusted by adjusting the thickness of the coating pattern 10B. When the first opening 27H has a size close to the limit resolution of the photolithography process, the second opening 31H can be formed to a size smaller than the limit resolution of the photolithography process.

  The coating pattern 10B and the photoresist pattern 27 can constitute a mask pattern 31. That is, the mask pattern 31 and the second opening 31H are formed on the hard mask film 25. The hard mask film 25 is exposed in the second opening 31H.

  As shown in FIG. 6, a hard mask pattern 25 'having a third opening 25H can be formed by etching the exposed hard mask film 25 using the mask pattern 31 as an etching mask. When the hard mask film 25 has a configuration in which the pad oxide film 23 and the mask nitride film 24 are sequentially stacked, the hard mask pattern 25 ′ may have a configuration in which the pad oxide pattern 23 ′ and the mask nitride pattern 24 ′ are sequentially stacked. it can. The substrate 21 is exposed in the third opening 25H.

  For etching the hard mask film 25, for example, an anisotropic etching process can be applied. In that case, the size of the third opening 25H is determined by the size of the second opening 31H. That is, the third opening 25H can be formed with a size smaller than the limit resolution of the photolithography process.

  Furthermore, the fourth opening 21H can be formed by etching the exposed substrate 21 using the mask pattern 31 and the hard mask pattern 25 'as an etching mask. An anisotropic etching process may be applied to the etching of the exposed substrate 21. In this case, the size of the fourth opening 21H is determined by the third opening 25H. That is, the fourth opening 21H can be formed with a size smaller than the limit resolution of the photolithography process.

  As another method, the mask pattern 31 may be removed before the fourth opening 21H is formed. In this case, the fourth opening 21H can be formed using the hard mask pattern 25 'as an etching mask.

  As described above, the covering material 10 according to the embodiment of the present invention exhibits superior solubility as compared with the conventional covering material. For this reason, the slurry of the covering material 10 can be completely removed from the second opening 31H. In addition, the coating pattern 10B can be controlled to have a uniform thickness over the entire surface of the substrate 21. As a result, the third opening 25H and the fourth opening 21H can be formed in a desired size and form. That is, according to the embodiment of the present invention, a fine pattern having a size smaller than the limit resolution of the photolithography process can be formed.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the following examples are for illustrative purposes only and are not intended to limit the present invention.

(Experimental example 1)
Four photoresist pattern coating materials (first coating materials) having different contents of each component by mixing polyhydroxy acrylate (poly (hydroxyl) acrylate) as a water-soluble polymer and tetramethylene diamine (tetramethyldiamine) as an additive. To 4th coating material).

  That is, during the preparation, the content of tetramethylenediamine as an additive is 0.3% by weight with respect to the total amount of the photoresist pattern coating material, and the first coating material is 0.2% by weight. 2 coating materials, 0.1 wt% third coating material, and 0 wt% fourth coating material were prepared. Therefore, the fourth covering material was formed only from polyhydroxy acrylate which is a water-soluble polymer.

  Next, wafers having a photoresist pattern having the same shape / size were prepared, and the first to fourth coating materials prepared above were respectively applied to the surface of the wafer. Thereafter, a coating pattern covering the surface of the photoresist pattern is formed on the surface of the wafer, the surface of the wafer having the coating pattern is washed to remove the coating material, and the surface of the wafer having the coating pattern is observed. did.

  As a result, on the surface of the wafer having the coating pattern formed using the first and second coating materials, contact hole opening due to the coating material residue and micro-bridging may occur. No bad pattern was found.

  On the other hand, in the case of the fourth covering material, pattern defects such as clogging of many contact holes and micro-bridging were found.

  In the case of the third covering material, although very slight micro-bridging was partially observed, the micro-bridging tended to be significantly reduced as compared with the case of the fourth covering material. Also, no contact hole clogging was observed.

(Experimental example 2)
Four photoresist pattern coating materials (fifth coating) with different contents of each component are mixed with polyhydroxy acrylate, which is a water-soluble polymer, tetramethylene diamine, which is an additive, ethylene urea carboxylic acid, which is a crosslinking agent, and water. Material-8th covering material) was prepared.

  That is, in the above preparation, the content of tetramethylene diamine as an additive is 0.3% by weight with respect to the total amount of the photoresist pattern coating material, the fifth coating material being 0.2% by weight. Six coating materials, a seventh coating material of 0.1% by weight, and an eighth coating material of 0% by weight were prepared. Therefore, the above-mentioned eighth covering material was formed by mixing polyhydroxy acrylate, which is a water-soluble polymer, ethylene urea carboxylic acid, which is a crosslinking agent, and water without containing an additive.

  Next, wafers having a photoresist pattern having the same shape / size were prepared, and the fifth to eighth coating materials were applied to the surface of the wafer. Thereafter, a coating pattern covering the surface of the photoresist pattern is formed on the surface of the wafer, the surface of the wafer having the coating pattern is washed to remove the coating material, and the surface of the wafer having the coating pattern is observed. did.

  As a result, on the surface of the wafer having the coating pattern formed using the fifth and sixth coating materials, pattern defects such as contact hole clogging and / or micro-bridging due to the coating material residue were found. Was not.

  On the other hand, in the case of the eighth covering material, pattern defects such as clogging of many contec holes and / or micro-bridging were found.

  In the case of the seventh covering material, although very slight micro-bridging was partially observed, the micro-bridging tended to be remarkably reduced as compared with the case of the eighth covering material. Also, no contact hole clogging was observed.

It is sectional drawing for demonstrating the fine pattern formation method using the coating material for photoresist patterns which concerns on embodiment of this invention. It is sectional drawing for demonstrating the fine pattern formation method using the coating material for photoresist patterns which concerns on embodiment of this invention. It is sectional drawing for demonstrating the fine pattern formation method using the coating material for photoresist patterns which concerns on embodiment of this invention. It is sectional drawing for demonstrating the fine pattern formation method using the coating material for photoresist patterns which concerns on embodiment of this invention. It is sectional drawing for demonstrating the fine pattern formation method using the coating material for photoresist patterns which concerns on embodiment of this invention. It is sectional drawing for demonstrating the fine pattern formation method using the coating material for photoresist patterns which concerns on embodiment of this invention.

Explanation of symbols

10 Coating material for photoresist pattern,
10A coating layer,
10B coating pattern,
10R cross-linking,
11 Water-soluble polymer,
13 Additives,
15 crosslinker,
17 Water,
21 substrate,
21H fourth opening,
23 Pad oxide film,
23 'pad oxidation pattern,
24 mask nitride film,
24 'mask nitriding pattern,
25 Hard mask film,
25 'hard mask pattern,
25H third opening,
27 photoresist pattern,
27H first opening,
31 mask pattern,
31H Second opening.

Claims (14)

A water-soluble polymer and an additive,
The coating material for a photoresist pattern, wherein the additive is at least one selected from the group consisting of compounds represented by the following chemical formula 1 or chemical formula 2.

[Wherein X and Y are each independently any one selected from the group consisting of N, O and S, and R ₁ to R ₈ are each independently an alkyl group having 1 to 5 carbon atoms and Any one selected from the group consisting of -H. ]

[Wherein, Z and W are each independently any one selected from the group consisting of N, O and S, and R ₁₁ to R ₁₇ are each independently an alkyl group having 1 to 5 carbon atoms and Any one selected from the group consisting of -H. ]   The additive is 2- (methylamino) ethanol, 2- (dimethylamino) ethanol, 2-methoxy-N-methylethanamine, 2-methoxy-N, N-dimethylethanamine, 2-ethoxy-N-methyl. Ethanamine, 2-ethoxy-N, N-dimethylethanamine, N-methyl-2-propoxyethanamine, N, N-dimethyl-2-propoxyethanamine, 2-isopropoxy-N-methylethanamine, 2- Isopropoxy-N, N-dimethylethanamine, N-ethyl-2-isopropoxyethanamine, 2- (ethylamino) ethanol, N-ethyl-2-methoxyethanamine, 2-ethoxy-N-ethylethanamine, N, N-diethyl-2-isopropoxyethanamine, N, N-diethyl-2-methoxyethanamine 2-ethoxy-N, N-diethylethanamine, 2- (diethylamino) ethanol, 2-isopropoxyethanamine, 2-methoxyethanamine, 2-ethoxyethanamine, 2-aminoethanol, 2-aminoethanethiol, 2- (methylthio) ethanamine, 2- (ethylthio) ethanamine, 2- (isopropylthio) ethanamine, 2- (isopropylthio) ethanamine, 2- (methylamino) ethanethiol, N-methyl-2- (methylthio) methanamine, 2- (ethylthio) -N-methylethanamine, 2- (isopropylthio) -N-methylethanamine, 2- (isopropylthio) -N-methylethanamine, 2- (ethylamino) ethanethiol, N-ethyl -2- (methylthio) ethanamine, N-ethi 2- (ethylthio) ethanamine, N-ethyl-2- (isopropylthio) ethanamine, N-ethyl-2- (isopropylthio) ethanamine, 2- (diethylamino) ethanethiol, N, N-diethyl-2- (methylthio) ) Ethanamine, N, N-diethyl-2- (ethylthio) ethanamine, N, N-diethyl-2- (isopropylthio) ethanamine, tetramethylenediamine, and N, N-diethyl-2- (isopropylthio) ethanamine The coating material for a photoresist pattern according to claim 1, wherein the coating material is at least one selected from the group. The said water-soluble polymer has a repeating structural unit represented by following Chemical formula 3, The covering material for photoresist patterns of Claim 1 or 2 characterized by the above-mentioned.

[Wherein R ₂₁ is an acyl group having 2 to 6 carbon atoms, and R ₂₂ is an alkyl group having 1 to 3 carbon atoms (in this case, R ₂₂ forms an acetal in the polymer molecule). K is an integer of 1 to 150, and m and n are each independently an integer of 1 to 120. ] In Formula 3, m and n are each independently an integer of 1 to 100,
4. The coating material for a photoresist pattern according to claim 3, wherein R ₂₁ is an acetyl group, and R ₂₂ forms an acetal in a polymer molecule. 5. The water-soluble polymer is polyhydroxy acrylate,
The coating material for a photoresist pattern according to claim 1, wherein the additive is tetramethylenediamine.   The coating material for a photoresist pattern according to claim 1, further comprising a crosslinking agent and water.   The coating material for a photoresist pattern according to claim 6, wherein the crosslinking agent is at least one selected from the group consisting of a melamine derivative, a urea derivative, and a uril derivative. Preparing a coating material for a photoresist pattern according to any one of claims 1 to 7,
Applying the coating on a substrate having a photoresist pattern;
Forming a coating pattern on the photoresist pattern by cross-linking the coating material and the photoresist pattern to form a fine pattern. After forming the coating pattern,
Removing the unreacted coating material to expose the substrate between the photoresist patterns;
The method of claim 8, further comprising: etching the exposed substrate using the covering pattern and the photoresist pattern as an etching mask.   The method of forming a fine pattern according to claim 8 or 9, further comprising forming a hard mask film covering the substrate under the photoresist pattern. The step of forming the hard mask film includes:
Forming a pad oxide film on the substrate;
The method for forming a fine pattern according to claim 10, comprising: forming a mask nitride film on the pad oxide film. After forming the coating pattern,
Removing the unreacted coating material to expose the hard mask film between the photoresist patterns;
The method of claim 10, further comprising: forming a hard mask pattern by etching the exposed hard mask film using the coating pattern and the photoresist pattern as an etching mask. Fine pattern forming method.   The method of claim 12, further comprising etching the substrate using the hard mask pattern as an etching mask.   The method for forming a fine pattern according to any one of claims 8 to 13, wherein the crosslinking reaction is performed at a temperature of 80 to 250C using a baking process.

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