Process liquid for extreme ultraviolet lithography and pattern forming method using same

Abstract

Proposed are a processing solution for reducing the incidence of pattern collapse and the number of defects in a photoresist pattern including polyhydroxystyrene using extreme ultraviolet rays as an exposure source, and a method of forming a pattern using the same. The processing solution for reducing the incidence of photoresist pattern collapse and the number of defects includes 0.0001 to 1 wt % of an alkaline material, 0.0001 to 1 wt % of an anionic surfactant, and 98 to 99.9998 wt % of water.

Claims

1. A processing solution for reducing incidence of pattern collapse and a number of defects in a photoresist pattern comprising polyhydroxystyrene during photoresist patterning using extreme ultraviolet rays as a light source, the processing solution consisting of: 0.001 to 0.1 wt % of an anionic surfactant selected from the group consisting of a polycarboxylic acid salt, a sulfonic acid salt, a sulfuric acid ester salt, and mixtures thereof; 0.001 to 0.1 wt % of an alkaline material selected from the group consisting of tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and mixtures thereof; and 99.8 to 99.998 wt % of water.

2. The processing solution of claim 1, wherein the anionic surfactant is a polycarboxylic acid salt.

3. A method of forming a photoresist pattern, comprising: (a) forming a photoresist film by applying a photoresist on a semiconductor substrate; (b) forming a photoresist pattern by exposing the photoresist film to extreme ultraviolet rays and then performing development; and (c) cleaning the photoresist pattern with the processing solution of claim 2.

4. The processing solution of claim 1, wherein the anionic surfactant is a sulfonic acid salt.

5. A method of forming a photoresist pattern, comprising: (a) forming a photoresist film by applying a photoresist on a semiconductor substrate; (b) forming a photoresist pattern by exposing the photoresist film to extreme ultraviolet rays and then performing development; and (c) cleaning the photoresist pattern with the processing solution of claim 4.

6. The processing solution of claim 1, wherein the anionic surfactant is a sulfuric acid ester salt.

7. A method of forming a photoresist pattern, comprising: (a) forming a photoresist film by applying a photoresist on a semiconductor substrate; (b) forming a photoresist pattern by exposing the photoresist film to extreme ultraviolet rays and then performing development; and (c) cleaning the photoresist pattern with the processing solution of claim 6.

8. The processing solution of claim 1, wherein the alkaline material is selected from the group consisting of tetraethylammonium hydroxide, tetrabutylammonium hydroxide, and mixtures thereof.

9. The processing solution of claim 8, wherein the alkaline material is tetraethylammonium hydroxide.

10. A method of forming a photoresist pattern, comprising: (a) forming a photoresist film by applying a photoresist on a semiconductor substrate; (b) forming a photoresist pattern by exposing the photoresist film to extreme ultraviolet rays and then performing development; and (c) cleaning the photoresist pattern with the processing solution of claim 9.

11. The processing solution of claim 8, wherein the alkaline material is tetrabutylammonium hydroxide.

12. A method of forming a photoresist pattern, comprising: (a) forming a photoresist film by applying a photoresist on a semiconductor substrate; (b) forming a photoresist pattern by exposing the photoresist film to extreme ultraviolet rays and then performing development; and (c) cleaning the photoresist pattern with the processing solution of claim 11.

13. A method of forming a photoresist pattern, comprising: (a) forming a photoresist film by applying a photoresist on a semiconductor substrate; (b) forming a photoresist pattern by exposing the photoresist film to extreme ultraviolet rays and then performing development; and (c) cleaning the photoresist pattern with the processing solution of claim 8.

14. A method of forming a photoresist pattern, comprising: (a) forming a photoresist film by applying a photoresist on a semiconductor substrate; (b) forming a photoresist pattern by exposing the photoresist film to extreme ultraviolet rays and then performing development; and (c) cleaning the photoresist pattern with the processing solution of claim 1.

Description

BEST MODE

(1) Hereinafter, a detailed description will be given of the present disclosure.

(2) The present disclosure, which is the culmination of extensive long-term study, pertains to a processing solution for reducing the incidence of photoresist pattern collapse and the number of defects, including 0.0001 to 1 wt % of an alkaline material selected from the group consisting of tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and mixtures thereof, 0.0001 to 1 wt % of an anionic surfactant selected from the group consisting of a polycarboxylic acid salt, a sulfonic acid salt, a sulfuric acid ester salt, a phosphoric acid ester salt, and mixtures thereof, and 98 to 99.9998 wt % of water. The components and amounts of the processing solution of the present disclosure were set according to Example 1 to Example 40, and the components and amounts for comparison therewith were set according to Comparative Example 1 to Comparative Example 22.

(3) Preferred examples of the present disclosure and comparative examples for comparison therewith are described below. However, the following examples are merely a preferred embodiment of the present disclosure, and the present disclosure is not limited to the following examples.

Mode for Disclosure

Example 1

(4) A processing solution for reducing the incidence of collapse of a photoresist pattern, including 0.0001 wt % of a polycarboxylic acid ammonium salt and 0.01 wt % of tetrabutylammonium hydroxide, was prepared as follows.

(5) 0.0001 wt % of a polycarboxylic acid ammonium salt and 0.01 wt % of tetrabutylammonium hydroxide were added to a balance of distilled water, stirred for 5 hours, and passed through a 0.01 μm filter to remove fine solid impurities, thereby preparing a processing solution for reducing the incidence of collapse of a photoresist pattern.

Example 2 to Example 40

(6) Respective processing solutions for reducing the number of defects of a photoresist pattern were prepared in the same manner as in Example 1 using components in the amounts shown in Tables 1 to 12 below.

Comparative Example 1

(7) Distilled water, which is typically used as the final cleaning solution in a development process during manufacture of a semiconductor device, was prepared.

Comparative Example 2 to Comparative Example 22

(8) For comparison with Examples, respective processing solutions were prepared in the same manner as in Example 1 using components in the amounts shown in Tables 1 to 12 below.

Test Example 1 to Test Example 40 and Comparative Test Example 1 to Comparative Test Example 22

(9) The incidence of pattern collapse and the defect number reduction ratio in a silicon wafer having a pattern in each of Example 1 to Example 40 and Comparative Example 1 to Comparative Example 22 were measured. The results thereof are shown as Test Example 1 to Test Example 40 and Comparative Test Example 1 to Comparative Test Example 22 in Tables 13 and 14 below.

(10) (1) Prevention of Pattern Collapse

(11) After exposure and focus splitting, the number of blocks in which the pattern did not collapse, out of the total of 89 blocks, was measured using a critical dimension scanning electron microscope (CD-SEM, Hitachi).

(12) (2) Defect Number Reduction Ratio

(13) For the photoresist pattern rinsed with each processing solution sample using a surface defect observation device [KLA, Tencor], the number of defects (A) was measured and expressed as a percentage (%) of the number of defects (B) observed upon rinsing with pure water alone, that is, (A/B)×100.

(14) The number of defects after treatment with pure water alone was set to 100% as a standard, and the extent of decrease (improvement) or increase (aggravation) compared to the number of defects when treated with pure water alone was expressed as a reduction ratio.

(15) (3) Transparency

(16) The transparency of the prepared processing solution was observed with the naked eye and classified as transparent or opaque.

(17) TABLE-US-00001 TABLE 1 Surfactant Alkaline material Distilled water Amount Amount Amount Name (wt %) Name (wt %) Name (wt %) Example 1 Polycarboxylic acid 0.0001 Tetrabutylammonium 0.01 Distilled 99.9899 ammonium salt hydroxide water Example 2 Polycarboxylic acid 0.001 Tetrabutylammonium 0.01 Distilled 99.9890 ammonium salt hydroxide water Example 3 Polycarboxylic acid 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 ammonium salt hydroxide water Example 4 Polycarboxylic acid 0.1 Tetrabutylammonium 0.01 Distilled 99.8900 ammonium salt hydroxide water Example 5 Polycarboxylic acid 1 Tetrabutylammonium 0.01 Distilled 98.9900 ammonium salt hydroxide water Comparative — — — — Distilled 100 Example 1 water Comparative — — Tetrabutylammonium 0.01 Distilled 99.9900 Example 2 hydroxide water Comparative Polycarboxylic acid 2 Tetrabutylammonium 0.01 Distilled 97.9900 Example 3 ammonium salt hydroxide water

(18) TABLE-US-00002 TABLE 2 Surfactant Alkaline material Distilled water Amount Amount Amount Name (wt %) Name (wt %) Name (wt %) Example 6 Sulfonic 0.0001 Tetrabutylammonium 0.01 Distilled 99.9899 acid salt hydroxide water Example 7 Sulfonic 0.001 Tetrabutylammonium 0.01 Distilled 99.9890 acid salt hydroxide water Example 8 Sulfonic 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 acid salt hydroxide water Example 9 Sulfonic 0.1 Tetrabutylammonium 0.01 Distilled 99.8900 acid salt hydroxide water Example 10 Sulfonic 1 Tetrabutylammonium 0.01 Distilled 98.9900 acid salt hydroxide water Comparative — — — — Distilled 100 Example 1 water Comparative — — Tetrabutylammonium 0.01 Distilled 99.9900 Example 2 hydroxide water Comparative Sulfonic 2 Tetrabutylammonium 0.01 Distilled 97.9900 Example 4 acid salt hydroxide water

(19) TABLE-US-00003 TABLE 3 Surfactant Alkaline material Distilled water Amount Amount Amount Amount (wt %) Name (wt %) (wt %) Name (wt %) Example 11 Sulfuric acid 0.0001 Tetrabutylammonium 0.01 Distilled 99.9899 ester salt hydroxide water Example 12 Sulfuric acid 0.001 Tetrabutylammonium 0.01 Distilled 99.9890 ester salt hydroxide water Example 13 Sulfuric acid 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 ester salt hydroxide water Example 14 Sulfuric acid 0.1 Tetrabutylammonium 0.01 Distilled 99.8900 ester salt hydroxide water Example 15 Sulfuric acid 1 Tetrabutylammonium 0.01 Distilled 98.9900 ester salt hydroxide water Comparative — — — — Distilled 100 Example 1 water Comparative — — Tetrabutylammonium 0.01 Distilled 99.9900 Example 2 hydroxide water Comparative Sulfuric acid 2 Tetrabutylammonium 0.01 Distilled 97.9900 Example 5 ester salt hydroxide water

(20) TABLE-US-00004 TABLE 4 Surfactant Alkaline material Distilled water Amount Amount Amount Amount (wt %) Name (wt %) (wt %) Name (wt %) Example 16 Phosphoric 0.0001 Tetrabutylammonium 0.01 Distilled 99.9899 acid ester salt hydroxide water Example 17 Phosphoric 0.001 Tetrabutylammonium 0.01 Distilled 99.9890 acid ester salt hydroxide water Example 18 Phosphoric 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 acid ester salt hydroxide water Example 19 Phosphoric 0.1 Tetrabutylammonium 0.01 Distilled 99.8900 acid ester salt hydroxide water Example 20 Phosphoric 1 Tetrabutylammonium 0.01 Distilled 98.9900 acid ester salt hydroxide water Comparative — — — — Distilled 100 Example 1 water Comparative — — Tetrabutylammonium 0.01 Distilled 99.9900 Example 2 hydroxide water Comparative Phosphoric 2 Tetrabutylammonium 0.01 Distilled 97.9900 Example 6 acid ester salt hydroxide water

(21) TABLE-US-00005 TABLE 5 Surfactant Alkaline material Distilled water Amount Amount Amount Amount (wt %) Name (wt %) (wt %) Name (wt %) Example 21 Polycarboxylic acid 0.01 Tetrabutylammonium 0.0001 Distilled 99.9899 ammonium salt hydroxide water Example 22 Polycarboxylic acid 0.01 Tetrabutylammonium 0.001 Distilled 99.9890 ammonium salt hydroxide water Example 3 Polycarboxylic acid 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 ammonium salt hydroxide water Example 23 Polycarboxylic acid 0.01 Tetrabutylammonium 0.1 Distilled 99.8900 ammonium salt hydroxide water Example 24 Polycarboxylic acid 0.01 Tetrabutylammonium 1 Distilled 98.9900 ammonium salt hydroxide water Comparative Polycarboxylic acid 0.01 — — Distilled 99.9900 Example 7 ammonium salt water Comparative Polycarboxylic acid 0.01 Tetrabutylammonium 2 Distilled 97.9900 Example 8 ammonium salt hydroxide water

(22) TABLE-US-00006 TABLE 6 Surfactant Alkaline material Distilled water Amount Amount Amount Amount (wt %) Name (wt %) (wt %) Name (wt %) Example 25 Sulfonic 0.01 Tetrabutylammonium 0.0001 Distilled 99.9899 acid salt hydroxide water Example 26 Sulfonic 0.01 Tetrabutylammonium 0.001 Distilled 99.9890 acid salt hydroxide water Example 8 Sulfonic 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 acid salt hydroxide water Example 27 Sulfonic 0.01 Tetrabutylammonium 0.1 Distilled 99.8900 acid salt hydroxide water Example 28 Sulfonic 0.01 Tetrabutylammonium 1 Distilled 98.9900 acid salt hydroxide water Comparative Sulfonic 0.01 — — Distilled 99.9900 Example 9 acid salt water Comparative Sulfonic 0.01 Tetrabutylammonium 2 Distilled 97.9900 Example 10 acid salt hydroxide water

(23) TABLE-US-00007 TABLE 7 Surfactant Alkaline material Distilled water Amount Amount Amount Amount (wt %) Name (wt %) (wt %) Name (wt %) Example 29 Sulfuric acid 0.01 Tetrabutylammonium 0.0001 Distilled 99.9899 ester salt hydroxide water Example 30 Sulfuric acid 0.01 Tetrabutylammonium 0.001 Distilled 99.9890 ester salt hydroxide water Example 13 Sulfuric acid 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 ester salt hydroxide water Example 31 Sulfuric acid 0.01 Tetrabutylammonium 0.1 Distilled 99.8900 ester salt hydroxide water Example 32 Sulfuric acid 0.01 Tetrabutylammonium 1 Distilled 98.9900 ester salt hydroxide water Comparative Sulfuric acid 0.01 — — Distilled 99.9900 Example 11 ester salt water Comparative Sulfuric acid 0.01 Tetrabutylammonium 2 Distilled 97.9900 Example 12 ester salt hydroxide water

(24) TABLE-US-00008 TABLE 8 Surfactant Alkaline material Distilled water Amount Amount Amount Amount (wt %) Name (wt %) (wt %) Name (wt %) Example 33 Phosphoric 0.01 Tetrabutylammonium 0.0001 Distilled 99.9899 acid ester salt hydroxide water Example 34 Phosphoric 0.01 Tetrabutylammonium 0.001 Distilled 99.9890 acid ester salt hydroxide water Example 18 Phosphoric 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 acid ester salt hydroxide water Example 35 Phosphoric 0.01 Tetrabutylammonium 0.1 Distilled 99.8900 acid ester salt hydroxide water Example 36 Phosphoric 0.01 Tetrabutylammonium 1 Distilled 98.9900 acid ester salt hydroxide water Comparative Phosphoric 0.01 — — Distilled 99.9900 Example 13 acid ester salt water Comparative Phosphoric 0.01 Tetrabutylammonium 2 Distilled 97.9900 Example 14 acid ester salt hydroxide water

(25) TABLE-US-00009 TABLE 9 Surfactant Alkaline material Distilled water Amount Amount Amount Amount (wt %) Name (wt %) (wt %) Name (wt %) Example 3 Polycarboxylic acid 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 ammonium salt hydroxide water Example 37 Polycarboxylic acid 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 ammonium salt hydroxide water Comparative Polycarboxylic acid 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 Example 15 ammonium salt hydroxide water Comparative Polycarboxylic acid 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 Example 16 ammonium salt hydroxide water

(26) TABLE-US-00010 TABLE 10 Surfactant Alkaline material Distilled water Amount Amount Amount Amount (wt %) Name (wt %) (wt %) Name (wt %) Example 8 Sulfonic 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 acid salt hydroxide water Example 38 Sulfonic 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 acid salt hydroxide water Comparative Sulfonic 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 Example 17 acid salt hydroxide water Comparative Sulfonic 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 Example 18 acid salt hydroxide water

(27) TABLE-US-00011 TABLE 11 Surfactant Alkaline material Distilled water Amount Amount Amount Amount (wt %) Name (wt %) (wt %) Name (wt %) Example 13 Sulfuric acid 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 ester salt hydroxide water Example 39 Sulfuric acid 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 ester salt hydroxide water Comparative Sulfuric acid 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 Example 19 ester salt hydroxide water Comparative Sulfuric acid 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 Example 20 ester salt hydroxide water

(28) TABLE-US-00012 TABLE 12 Surfactant Alkaline material Distilled water Amount Amount Amount Amount (wt %) Name (wt %) (wt %) Name (wt %) Example 18 Phosphoric 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 acid ester salt hydroxide water Example 40 Phosphoric 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 acid ester salt hydroxide water Comparative Phosphoric 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 Example 21 acid ester salt hydroxide water Comparative Phosphoric 0.01 Tetrabutylammonium 0.01 Distilled 99.9800 Example 22 acid ester salt hydroxide water

Test Example 1 to Test Example 40 and Comparative Test Example 1 to Comparative Test Example 22

(29) The incidence of pattern collapse, the defect number reduction ratio, and transparency in a silicon wafer having a pattern in each of Example 1 to Example 40 and Comparative Example 1 to Comparative Example 22 were measured. The results thereof are shown as Test Example 1 to Test Example 40 and Comparative Test Example 1 to Comparative Test Example 22 in Tables 13 and 14 below.

(30) (1) Incidence of Pattern Collapse

(31) After exposure and focus splitting, the number of blocks in which the pattern did not collapse, out of the total of 89 blocks, was measured using a critical dimension scanning electron microscope (CD-SEM, Hitachi).

(32) (2) Defect Number Ratio

(33) For the photoresist pattern rinsed with each processing solution sample using a surface defect observation device [KLA, Tencor], the number of defects (A) was measured and expressed as a percentage (%) of the number of defects (B) observed upon rinsing with pure water alone, that is, (A/B)×100.

(34) (3) Transparency

(35) The transparency of the prepared processing solution was observed with the naked eye and classified as transparent or opaque.

(36) TABLE-US-00013 TABLE 13 Number of blocks not Defect exhibiting number pattern reduction collapse ratio (%) Transparency Test Example 1 55 53 Transparent Test Example 2 63 46 Transparent Test Example 3 81 25 Transparent Test Example 4 64 35 Transparent Test Example 5 68 80 Transparent Test Example 6 53 52 Transparent Test Example 7 61 48 Transparent Test Example 8 76 30 Transparent Test Example 9 65 36 Transparent Test Example 10 67 75 Transparent Test Example 11 52 56 Transparent Test Example 12 64 47 Transparent Test Example 13 75 31 Transparent Test Example 14 62 38 Transparent Test Example 15 66 72 Transparent Test Example 16 52 56 Transparent Test Example 17 68 50 Transparent Test Example 18 76 33 Transparent Test Example 19 65 38 Transparent Test Example 20 69 78 Transparent Test Example 21 70 81 Transparent Test Example 22 72 53 Transparent Test Example 23 75 38 Transparent Test Example 24 66 84 Transparent Test Example 25 69 80 Transparent Test Example 26 70 52 Transparent Test Example 27 71 40 Transparent Test Example 28 65 87 Transparent Test Example 29 72 76 Transparent Test Example 30 70 50 Transparent Test Example 31 76 37 Transparent Test Example 32 68 88 Transparent Test Example 33 67 80 Transparent Test Example 34 71 52 Transparent Test Example 35 72 40 Transparent Test Example 36 66 86 Transparent Test Example 37 57 69 Transparent Test Example 38 59 70 Transparent Test Example 39 55 71 Transparent Test Example 40 60 65 Transparent

(37) TABLE-US-00014 TABLE 14 Number of blocks not Defect exhibiting number pattern reduction collapse ratio (%) Transparency Comparative Test Example 1 46 100 Transparent Comparative Test Example 2 40 95 Transparent Comparative Test Example 3 37 276 Opaque Comparative Test Example 4 38 269 Opaque Comparative Test Example 5 36 274 Opaque Comparative Test Example 6 35 281 Opaque Comparative Test Example 7 58 127 Transparent Comparative Test Example 8 41 157 Transparent Comparative Test Example 9 59 129 Transparent Comparative Test Example 10 39 160 Transparent Comparative Test Example 11 57 124 Transparent Comparative Test Example 12 40 159 Transparent Comparative Test Example 13 59 120 Transparent Comparative Test Example 14 42 151 Transparent Comparative Test Example 15 52 142 Transparent Comparative Test Example 16 50 99 Transparent Comparative Test Example 17 49 140 Transparent Comparative Test Example 18 51 101 Transparent Comparative Test Example 19 54 138 Transparent Comparative Test Example 20 49 97 Transparent Comparative Test Example 21 53 151 Transparent Comparative Test Example 22 50 98 Transparent

(38) Based on the results of comparison of Test Example 1 to Test Example 40 with Comparative Test Example 1 to Comparative Test Example 22, when the number of blocks not exhibiting pattern collapse was 50 or more and the defect number reduction ratio was 90% or less relative to Comparative Test Example 1, results were considered to be superior.

(39) In the processing solutions according to Test Example 1 to Test Example 40, including 0.0001 to 1 wt % of the anionic surfactant selected from among a polycarboxylic acid salt, a sulfonic acid salt, a sulfuric acid ester salt, and a phosphoric acid ester salt, 0.0001 to 1 wt % of the alkaline material selected from among tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide, and 98 to 99.9998 wt % of water, the incidence of pattern collapse was reduced and the number of defects was also reduced, compared to Comparative Test Example 1 to Comparative Test Example 22.

(40) In particular, Test Examples 2 to 4, Test Examples 7 to 9, Test Examples 12 to 14, Test Examples 17 to 19, Test Examples 22 and 23, Test Examples 26 and 27, Test Examples 30 and 31, and Test Examples 34 and 35 exhibited more preferable results.

(41) Specifically, the processing solution for reducing the incidence of photoresist pattern collapse and the number of defects according to each of Test Examples 2 to 4, Test Examples 7 to 9, Test Examples 12 to 14, Test Examples 17 to 19, Test Examples 22 and 23, Test Examples 26 and 27, Test Examples 30 and 31, and Test Examples 34 and 35, including 0.001 to 0.1 wt % of the anionic surfactant selected from among a polycarboxylic acid salt, a sulfonic acid salt, a sulfuric acid ester salt, and a phosphoric acid ester salt, 0.001 to 0.1 wt % of the alkaline material selected from among tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide, and 99.8 to 99.998 wt % of water, was confirmed to exhibit reduced pattern collapse and a reduced number of defects compared to Comparative Test Examples and other Test Examples, indicating that the above concentration ranges are more preferable.

(42) Based on the result of evaluation of the incidence of photoresist pattern collapse according to Example 3, the number of blocks not exhibiting pattern collapse was measured to be 81.

(43) Based on the result of evaluation of the incidence of photoresist pattern collapse according to Comparative Test Example 1, the number of blocks not exhibiting pattern collapse was measured to be 46.

(44) Although specific embodiments of the present disclosure have been disclosed in detail above, it will be obvious to those skilled in the art that the description is merely of preferable exemplary embodiments and is not to be construed to limit the scope of the present disclosure. Therefore, the substantial scope of the present disclosure will be defined by the appended claims and equivalents thereof.