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

Abstract

A processing solution composition for reducing micro-bridge defects in a polyhydroxystyrene-containing photoresist pattern defined by an extreme-ultraviolet exposure source and a method of forming a pattern using the same are proposed. The processing solution composition includes 0.0001 to 1 wt % of an alkaline material, 0.0001 to 1 wt % of a nonionic surfactant having an HLB (Hydrophilic-Lipophilic Balance) value of 9 to 16, and 98 to 99.9998 wt % of water, reduces the number of micro-bridge defects in a polyhydroxystyrene-containing photoresist pattern defined by an extreme-ultraviolet exposure source, and has a low LWR (Line Width Roughness) value, thus effectively improving the uniformity of the pattern.

Claims

1. 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 and developing the photoresist film; and (c) cleaning the photoresist pattern with a processing solution composition for photolithography, wherein the processing solution composition for reducing micro-bridge defects in a polyhydroxystyrene-containing photoresist pattern defined by an extreme-ultraviolet exposure source comprises: 0.0001 to 1 wt % of a nonionic surfactant having an HLB (Hydrophilic-Lipophilic Balance) value of 9 to 16; 0.0001 to 1 wt % of an alkaline material; and 98 to 99.9998 wt % of water.

2. The method of claim 1, wherein the exposing is performed using an extreme-ultraviolet exposure source.

3. The method of claim 1, wherein the nonionic surfactant is selected from the group consisting of polyoxyethylene alkyl ether, polyoxypropylene alkyl ether, polyoxyethylene oxypropylene alkyl ether, and mixtures thereof.

4. The method of claim 1, wherein the nonionic surfactant is polyoxyethylene alkyl ether.

5. The method of claim 1, wherein the HLB value of the nonionic surfactant is in a range of 12 to 16.

6. The method of claim 1, wherein the alkaline material is selected from the group consisting of tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and mixtures thereof.

7. The method of claim 1, wherein the alkaline material is tetrabutylammonium hydroxide.

Description

BEST MODE

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

(2) The present disclosure pertains to a processing solution for reducing the incidence of defects after photoresist development, including 0.0001 to 1 wt % of an alkaline material, 0.0001 to 1 wt % of a nonionic surfactant having an HLB (Hydrophilic-Lipophilic Balance) value of 9 to 16, and 98 to 99.9998 wt % of water.

(3) A better understanding of the present disclosure will be given through the following examples and comparative Examples. These examples are merely set forth to illustrate the present disclosure, and are not to be construed as limiting the scope of the present disclosure.

MODE FOR DISCLOSURE

Examples and Comparative Examples

Example 1

(4) A processing solution for reducing the incidence of defects in a photoresist pattern, including 0.0001 wt % of polyoxyethylene alkyl ether having an HLB value of 12 and 0.0001 wt % of tetrabutylammonium hydroxide, was prepared as follows.

(5) 0.0001 wt % of polyoxyethylene alkyl ether having an HLB value of 12 and 0.0001 wt % of tetrabutylammonium hydroxide were added to 99.9998 wt % of deionized (DI) water, stirred for 5 hr, and passed through a 0.02 μm filter to remove fine solid impurities, thereby preparing a processing solution for reducing the incidence of defects in a photoresist pattern.

Example 2 to Example 16

(6) Respective processing solutions for reducing the incidence of defects in a photoresist pattern were prepared in the same manner as in Example 1 using components in the amounts shown in Tables 1 to 5 below.

Comparative Example 1

(7) Pure water (DI water), which is typically used as the final processing solution of the development process in the process of manufacturing a semiconductor device, was prepared.

Comparative Example 2 to Comparative Example 9

(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 5 below.

(9) TABLE-US-00001 TABLE 1 Surfactant Alkaline material DI water Amount Amount Amount Name HLB (wt %) Name (wt %) Name (wt %) Example 1 Polyoxyethylene 12 0.0001 Tetrabutylammonium 0.0001 DI 99.9998 alkyl ether hydroxide water Example 2 Polyoxyethylene 12 0.01 Tetrabutylammonium 0.0001 DI 99.9989 alkyl ether hydroxide water Example 3 Polyoxyethylene 12 1 Tetrabutylammonium 0.0001 DI 98.9999 alkyl ether hydroxide water Comparative — — — — — DI 100 Example 1 water Comparative — — — Tetrabutylammonium 0.0001 DI 99.9999 Example 2 hydroxide water Comparative Polyoxyethylene 12 2 Tetrabutylammonium 0.0001 DI 97.9999 Example 3 alkyl ether hydroxide water

(10) TABLE-US-00002 TABLE 2 Surfactant Alkaline material DI water Amount Amount Amount Name HLB (wt %) Name (wt %) Name (wt %) Example 4 Polyoxyethylene 12 0.01 Tetrabutylammonium 0.01 DI 99.9800 alkyl ether hydroxide water Example 5 Polyoxyethylene 12 0.01 Tetrabutylammonium 1 DI 98.9900 alkyl ether hydroxide water Comparative Polyoxyethylene 12 0.01 — — DI 99.9900 Example 4 alkyl ether water Comparative Polyoxyethylene 12 0.01 Tetrabutylammonium 2 DI 97.9900 Example 5 alkyl ether hydroxide water

(11) TABLE-US-00003 TABLE 3 Surfactant Alkaline material DI water Amount Amount Amount Name HLB (wt %) Name (wt %) Name (wt %) Example 6 Polyoxyethylene 9 0.01 Tetrabutylammonium 0.01 DI 99.9800 alkyl ether hydroxide water Example 7 Polyoxyethylene 10 0.01 Tetrabutylammonium 0.01 DI 99.9800 alkyl ether hydroxide water Example 8 Polyoxyethylene 11 0.01 Tetrabutylammonium 0.01 DI 99.9800 alkyl ether hydroxide water Example 9 Polyoxyethylene 13 0.01 Tetrabutylammonium 0.01 DI 99.9800 alkyl ether hydroxide water Example 10 Polyoxyethylene 14 0.01 Tetrabutylammonium 0.01 DI 99.9800 alkyl ether hydroxide water Example 11 Polyoxyethylene 15 0.01 Tetrabutylammonium 0.01 DI 99.9800 alkyl ether hydroxide water Example 12 Polyoxyethylene 16 0.01 Tetrabutylammonium 0.01 DI 99.9800 alkyl ether hydroxide water Comparative Polyoxyethylene 8 0.01 Tetrabutylammonium 0.01 DI 99.9800 Example 6 alkyl ether hydroxide water Comparative Polyoxyethylene 17 0.01 Tetrabutylammonium 0.01 DI 99.9800 Example 7 alkyl ether hydroxide water

(12) TABLE-US-00004 TABLE 4 Surfactant Alkaline material DI water Amount Amount Amount Name HLB (wt %) Name (wt %) Name (wt %) Example Polyoxypropylene alkyl 12 0.01 Tetrabutylammonium 0.01 DI 99.9800 13 ether hydroxide water Example Polyoxyethylene 12 0.01 Tetrabutylammonium 0.01 DI 99.9800 14 oxypropylene alkyl ether hydroxide water

(13) TABLE-US-00005 TABLE 5 Surfactant Alkaline material DI water Amount Amount Amount Name HLB (wt %) Name (wt %) Name (wt %) Example 15 Polyoxyethylene 12 0.01 Tetraethylammonium 0.01 DI 99.9800 alkyl ether hydroxide water Example 16 Polyoxyethylene 12 0.01 Tetrapropylammonium 0.01 DI 99.9800 alkyl ether hydroxide water Comparative Polyoxyethylene 12 0.01 Tetrapentylammonium 0.01 DI 99.9800 Example 8 alkyl ether hydroxide water Comparative Polyoxyethylene 12 0.01 Tetramethylammonium 0.01 DI 99.9800 Example 9 alkyl ether hydroxide water

Test Examples and Comparative Test Examples

(14) The pattern, formed by applying a photoresist on a semiconductor substrate to form a photoresist film and exposing and developing the photoresist film to form a pattern, was cleaned using the processing solution composition of each of Example 1 to Example 16 and Comparative Example 1 to Comparative Example 9, after which the silicon wafer having the pattern formed thereon was measured for the defect number reduction ratio, LWR, and pattern collapse. The results thereof are shown as Test Example 1 to Test Example 16 and Comparative Test Example 1 to Comparative Test Example 9 in Table 6 below.

(15) (1) Micro-Bridge Defect Number Ratio

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

(17) The number of defects after treatment with pure water was set to 100% as a standard, and the extent of decrease or increase is expressed as a percentage compared to 100%, as the number of defects when treated with pure water alone, which is referred to as the micro-bridge defect number ratio (decrease or increase ratio). Here, a lower value is judged to be better.

(18) (2) LWR

(19) Using a critical dimension-scanning electron microscope (CD-SEM, Hitachi), the difference between the widest portion and the narrowest portion of the pattern was measured to determine the LWR value. The smaller the LWR value, the more uniform the pattern.

(20) The LWR value of the pattern treated with pure water alone was determined to be 5.9, and when the LWR was reduced using the prepared cleaning solution, it appears as a value lower than 5.9, and when it is deteriorated, it appears as a value higher than 5.9.

(21) (3) Pattern Collapse

(22) Using a critical dimension-scanning electron microscope (CD-SEM, Hitachi) and a scanning electron microscope (FE-SEM, Hitachi), whether the pattern collapsed was observed.

(23) When there is no pattern collapse, it is indicated as 0, whereas, when there is a pattern collapse, it is indicated by X, and pattern collapse is judged to be poor regardless of any reduction in the number of defects or LWR.

(24) TABLE-US-00006 TABLE 6 Micro-bridge defect LWR Pattern number ratio (%) (nm) collapse Example 1 75 5.5 ◯ Example 2 55 5.2 ◯ Example 3 82 5.1 ◯ Example 4 9 4.7 ◯ Example 5 15 4.5 ◯ Example 6 72 5.8 ◯ Example 7 58 4.6 ◯ Example 8 29 4.5 ◯ Example 9 12 4.6 ◯ Example 10 15 5.0 ◯ Example 11 19 5.3 ◯ Example 12 20 5.7 ◯ Example 13 15 4.9 ◯ Example 14 13 5.0 ◯ Example 15 15 4.0 ◯ Example 16 12 4.8 ◯ Comparative Example 1 100 5.9 X Comparative Example 2 90 6.0 X Comparative Example 3 112 5.3 X Comparative Example 4 60 6.3 ◯ Comparative Example 5 132 5.8 ◯ Comparative Example 6 182 6.4 ◯ Comparative Example 7 81 6.1 ◯ Comparative Example 8 33 6.2 ◯ Comparative Example 9 17 4.3 X ◯: No pattern collapse X: Pattern collapse

(25) Based on the results of comparison of Test Examples 1 to 3 with Comparative Test Examples 1 to 3, when the concentration of the surfactant was 0.0001 to 1 wt %, the number of micro-bridge defects was decreased, the LWR value was low and thus the uniformity of the pattern was improved, and there was no pattern collapse.

(26) Based on the results of comparison of Test Examples 2, 4 and 5 with Comparative Test Examples 1, 4 and 5, when the concentration of the alkaline material was 0.0001 to 1 wt %, the number of micro-bridge defects was decreased, the LWR value was low and thus the uniformity of the pattern was improved, and there was no pattern collapse.

(27) Based on the results of comparison of Test Examples 4 and 6 to 12 with Comparative Test Examples 1, 6 and 7, when the HLB value was 9 to 16, the number of micro-bridge defects was decreased, the LWR value was low and thus the uniformity of the pattern was improved, and there was no pattern collapse. In particular, when the HLB value was 12 to 16, vastly superior effects were exhibited.

(28) Based on the results of comparison of Test Examples 4, 13 and 14 with Comparative Test Example 1, when the surfactant was polyoxyethylene alkyl ether, polyoxypropylene alkyl ether, or polyoxyethylene oxypropylene alkyl ether, the number of micro-bridge defects was decreased, the LWR value was low and thus the uniformity of the pattern was improved, and there was no pattern collapse. In particular, when the surfactant was polyoxyethylene alkyl ether, vastly superior effects were exhibited.

(29) Based on the results of comparison of Test Examples 4, 15 and 16 with Comparative Test Examples 1, 8 and 9, when the alkaline material was tetraethylammonium hydroxide, tetrapropylammonium hydroxide, or tetrabutylammonium hydroxide, the number of micro-bridge defects was decreased, the LWR value was low and thus the uniformity of the pattern was improved, and there was no pattern collapse. In particular, when the alkaline material was tetrabutylammonium hydroxide, vastly superior effects were exhibited.

(30) 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.