Resist stripper composition and pattern forming method using same

Abstract

According to an embodiment of the present invention, a resist stripping solution composition and a pattern forming method using the same are provided. The resist stripping solution composition includes an alkaline compound including an ammonium hydroxide compound, ethanol, and a polar organic solvent including a sulfoxide compound. The resist stripping solution is provided with improved stripping speed and resist dissolving power.

Description

[Technical field]

[0001] The present invention relates to a resist stripping liquid composition and a pattern forming method using the same, and more particularly to a resist stripping liquid composition containing a stripping compound and a solvent, and a pattern forming method using the same. [Background technology]

[0002] 2. Description of the Related Art In semiconductor manufacturing processes and display panel manufacturing processes, processes using photoresist are performed. For example, a photoresist layer may be formed on a substrate, and the photoresist layer may be exposed and developed to form a photoresist pattern.

[0003] The photoresist pattern can be used as various mask patterns such as an etching mask, a mask for forming wiring, a mask for an ion implantation process, etc. After the above processes are performed, the photoresist pattern or the mask pattern can be removed by a stripping and / or ashing process.

[0004] For example, a stripping solution containing a compound having stripping properties for photoresist can be applied or sprayed onto the photoresist pattern to strip the photoresist pattern.

[0005] For efficient stripping of the photoresist pattern, it is preferable that the stripping solution has sufficient solubility for the polymeric material contained in the photoresist.

[0006] If the solubility of the stripping solution is insufficient, residues of the stripped photoresist may remain on the substrate, which may reduce the reliability of the semiconductor device or display device and cause product defects.

[0007] For example, Patent Document 1 (Korean Patent Publication No. 10-2016-0033855) discloses a resist stripping liquid composition containing an alkanolamine, but as described above, the composition may cause resist residue due to insufficient solubility. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Korean Patent Publication No. 10-2016-0033855 Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present invention is to provide a resist stripping solution composition having improved stripping efficiency and reliability.

[0010] An object of the present invention is to provide a pattern forming method using the resist remover composition. [Means for solving the problem]

[0011] 1. A resist stripping liquid composition comprising an alkaline compound containing an ammonium hydroxide compound, ethanol, and a polar organic solvent containing a sulfoxide compound.

[0012] 2. The resist stripping liquid composition according to item 1 above, wherein the polar organic solvent contains dimethyl sulfoxide.

[0013] 3. The resist stripping liquid composition according to item 1 above, wherein the alkaline compound further contains an amine compound.

[0014] 4. The resist stripping liquid composition according to item 3, wherein the amine compound includes an alkoxyalkylamine.

[0015] 5. In the above item 1, the resist stripping liquid composition contains A resist stripping liquid composition comprising 0.1 to 5% by weight of the ammonium hydroxide compound, 4 to 40% by weight of ethanol, and 55 to 95% by weight of the polar organic solvent.

[0016] 6. The resist stripping solution composition according to item 5, further comprising 0.1 to 5% by weight of deionized water relative to the total weight of the resist stripping solution composition.

[0017] 7. The resist stripping liquid composition according to item 6, wherein the difference between the content of the ammonium hydroxide compound and the content of the deionized water is 2% by weight or less.

[0018] 8. A pattern forming method comprising the steps of: forming a photoresist pattern on a substrate; forming a conductive pattern using the photoresist pattern; and removing the photoresist pattern using the resist stripper solution composition according to any one of the above embodiments.

[0019] 9. The pattern forming method according to item 8, wherein the step of removing the photoresist pattern includes removing a lower portion of the photoresist pattern with the resist stripper composition.

[0020] 10. The pattern forming method according to item 9, wherein the photoresist pattern includes a first photoresist pattern and a second photoresist pattern which are successively formed on the substrate, and are removed from the first photoresist pattern by the resist stripper solution composition.

[0021] 11. The pattern forming method according to claim 8, further comprising the step of forming a conductive layer on the substrate before forming the photoresist pattern.

[0022] 12. The pattern forming method according to item 8, wherein a plurality of the photoresist patterns are formed, and the step of forming the conductive pattern includes filling a conductive material between adjacent photoresist patterns. Effect of the Invention

[0023] The resist stripper composition according to the embodiment of the present invention may include an alkaline compound, ethanol, and a polar organic solvent. Ethanol has improved solubility for both the alkaline compound and the photoresist components. This improves the efficiency of photoresist stripping due to contact between the alkaline compound and the photoresist, while dissolving and removing the stripped photoresist components. This prevents the generation of photoresist residues after the stripping process, and improves the speed and efficiency of stripping.

[0024] In some embodiments, the stripping solution composition contains dimethyl sulfoxide as the polar organic solvent, which can effectively promote swelling of the photoresist and further improve the speed and efficiency of stripping. [Brief description of the drawings]

[0025] [Figure 1] 1 is a schematic cross-sectional view of a patterning method according to an exemplary embodiment; [Diagram 2] 1 is a schematic cross-sectional view of a patterning method according to an exemplary embodiment; [Diagram 3] 1 is a schematic cross-sectional view of a patterning method according to an exemplary embodiment; [Figure 4] 1 is a schematic cross-sectional view of a patterning method according to an exemplary embodiment; [Diagram 5] 1 is a schematic cross-sectional view of a patterning method according to an exemplary embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] According to an embodiment of the present invention, there is provided a resist stripper composition that includes an alkaline compound, ethanol, and a polar organic solvent, and that provides improved stripping efficiency and reliability. Also, there is provided a pattern forming method using the resist stripper composition.

[0027] Hereinafter, the present invention will be described in more detail with reference to the experimental examples and drawings. However, the embodiments attached to this specification are merely examples of preferred embodiments of the present invention, and serve to further understand the technical concept of the present invention together with the detailed description of the invention, and therefore the present invention should not be interpreted as being limited only to the matters described in the embodiments.

[0028] <Resist Stripping Solution Composition> A resist stripper solution composition according to an exemplary embodiment (hereinafter, may be abbreviated as "stripping solution composition") may include an alkaline compound, ethanol, and a polar organic solvent.

[0029] Alkaline Compounds The alkaline compound can be used as a compound having etching or stripping properties for the photoresist pattern hardened by the exposure and development processes. According to an exemplary embodiment, the alkaline compound can be included as a main stripping agent of the stripping solution composition.

[0030] For example, the alkaline compounds can break intramolecular or intermolecular bonds in the cured negative resist resin, and can also remove resist residues remaining on the substrate or wafer after the stripping process.

[0031] According to an exemplary embodiment, the alkaline compound may include an ammonium hydroxide-based compound. For example, the alkaline compound may include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, ethyltrimethylammonium hydroxide, tris(2-hydroxyethyl)methylammonium hydroxide, benzyltrimethylammonium hydroxide, etc. These may be used alone or in combination of two or more.

[0032] In some embodiments, the alkaline compound may further include an amine-based compound, which may be included as an auxiliary stripping agent to further improve stripping speed or efficiency.

[0033] For example, the amine-based compound may include a primary amine, a secondary amine, or a tertiary amine. In one embodiment, the amine-based compound may be an alkoxyamine or an alkoxyalkylamine, preferably an alkoxyalkylamine. In this case, the compatibility with the ammonium hydroxide-based compound and the dissolving power of the resist residue may be improved.

[0034] Non-limiting examples of said alkoxyalkylamines include 3-methoxypropylamine, 3-butoxypropylamine, 3-ethoxypropylamine, bis(2-methoxyethyl)amine, and the like.

[0035] In one embodiment, the alkali compound or the amine-based compound may not include a hydroxyl group-containing amine (e.g., alkanolamine or hydroxylamine). The hydroxyl group-containing amine may inhibit the stripping property of the ammonium hydroxide-based compound and may reduce the dissolving power of the stripping solution composition for resist residues. In addition, the metal pattern (e.g., copper wiring) may be oxidized or corroded during the stripping process, deteriorating the process reliability.

[0036] In some embodiments, the content of the ammonium hydroxide compound may be about 0.1 to 5 wt % based on the total weight of the stripping solution composition, which can provide sufficient stripping power for resist resin while suppressing corrosion of metal patterns.

[0037] Preferably, the content of the ammonium hydroxy compound may be about 0.3 to 5% by weight.

[0038] When the amine compound is contained, the content of the amine compound may be about 1 to 40% by weight, and preferably about 5 to 30% by weight, based on the total weight of the stripping liquid composition.

[0039] ethanol According to an exemplary embodiment, the stripping solution composition may include ethanol. Ethanol may be provided as a carrier or co-solvent for the ammonium hydroxide-based compound. Furthermore, ethanol may be absorbed into a negative resist pattern to swell the resist pattern. This may improve the penetration of the ammonium hydroxide-based compound into the resist pattern, thereby improving the stripping speed and stripping efficiency.

[0040] In some embodiments, the stripping solution composition may not contain an alcohol having 3 or more carbon atoms (represented by ROH, where R is an alcohol that is an alkyl group having 3 or more carbon atoms). The alcohol having 3 or more carbon atoms may rapidly reduce the dissolving power for the cured resist pattern. This may result in resist residue on the substrate or wafer, which may reduce the overall reliability of the stripping process.

[0041] In some embodiments, the stripping solution composition may be free of methanol. Methanol may be volatilized and removed during the stripping process, which may be performed at temperatures of, for example, 70° C. or higher. This may reduce the stability and reliability of the stripping process over time.

[0042] In one embodiment, alcohol other than ethanol (methanol or alcohol represented by ROH, where R is an alkyl group having 3 or more carbon atoms) may be contained in a small amount compared to ethanol, even if it is contained. For example, the alcohol other than ethanol may be contained in an amount of 1 / 2 or less of the weight of ethanol.

[0043] In some embodiments, the content of ethanol in the total weight of the stripping solution composition may be about 4 to 40 wt %. In this range, sufficient stripping power for the resist resin can be provided while suppressing corrosion of the metal pattern.

[0044] In a preferred embodiment, the ethanol content may be about 10-30% by weight.

[0045] solvent The polar organic solvent can dissolve the alkaline compound and swell the hardened resist pattern. In consideration of the solubility and swelling properties, the polar organic solvent can include a sulfur-containing organic solvent, and preferably a sulfoxide-based solvent.

[0046] According to an exemplary embodiment, dimethyl sulfoxide (DMSO) can be used as the polar organic solvent in consideration of providing stable peeling stability in a high-temperature peeling process performed at a temperature of 60° C. or 70° C. or higher and the solubility of alkaline compounds.

[0047] In some embodiments, the stripper composition may further include a water-soluble organic solvent, and the water-soluble organic solvent may include a compound different from the polar organic solvent.

[0048] By adding the water-soluble organic solvent, for example, the solubility of the hydrated alkaline compound can be improved, and swelling of the resist pattern can be further promoted.

[0049] For example, the water-soluble organic solvent may include a glycol solvent and / or a lactam solvent. Examples of the glycol solvent include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether (=butyl diglycol), and propylene glycol.

[0050] Examples of the lactam solvent include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N-hydroxymethyl-2-pyrrolidone, and N-hydroxyethyl-2-pyrrolidone.

[0051] For example, the polar organic solvent may be contained in an amount of about 55 to 95% by weight based on the total weight of the stripping solution composition. Preferably, the polar organic solvent may be contained in an amount of about 60 to 90% by weight. Within this range, sufficient swelling of the resist pattern and solubility of the alkaline compound can be ensured.

[0052] When the stripping liquid composition contains the water-soluble organic solvent, the content of the water-soluble organic solvent may be about 5 to 30% by weight, and preferably about 10 to 20% by weight, based on the total weight of the stripping liquid composition.

[0053] Other added ingredients In some embodiments, the stripper composition may further include deionized water, for example, deionized water may form a hydrate of the ammonium hydroxide-based compound, improving the solubility and dispersion properties of the ammonium hydroxide-based compound.

[0054] As described above, the deionized water may be contained in an amount substantially equivalent to the amount of the ammonium hydroxide-based compound. According to an exemplary embodiment, the content of the deionized water may be about 5 wt % or less, for example, about 0.1 to 5 wt %, based on the total weight of the stripping solution composition.

[0055] The deionized water may vary depending on the content of the ammonium hydroxide-based compound. In one embodiment, the difference between the content of the deionized water and the content of the ammonium hydroxide-based compound may be 2% by weight or less, preferably 1% by weight or less, more preferably 0.5% by weight or less, and even more preferably 0.1% by weight or less.

[0056] In one embodiment, the content of deionized water may be substantially the same as the content of the ammonium hydroxide-based compound.

[0057] In some embodiments, the stripping solution composition may contain additives in an amount that does not inhibit the above-mentioned effects of the stripping solution composition. Non-limiting examples of the additives include surfactants and anticorrosive agents known in the field of stripping processes. For example, the additives may be contained in an amount of less than about 1 wt % based on the total weight of the stripping solution composition.

[0058] According to an embodiment of the present invention, there is provided a pattern forming method using the aforementioned stripping solution composition.

[0059] 1 to 5 are schematic cross-sectional views of a pattern formation method according to an exemplary embodiment.

[0060] 1, a photoresist film 120 may be formed on a substrate 100. The substrate 100 may include a semiconductor substrate such as a silicon wafer.

[0061] The photoresist film 120 can be formed, for example, by applying and drying a negative photoresist composition. In some embodiments, the first photoresist film 122 and the second photoresist film 124 can be sequentially formed on the substrate 100 by multiple coating processes. This makes it possible to easily form the photoresist film 120 with a thick film structure.

[0062] In one embodiment, the first and second photoresist films 122, 124 may be formed substantially integrally.

[0063] In some embodiments, a conductive film 110 may further be formed between the photoresist film 120 and the substrate 100 .

[0064] 2, an exposure process (eg, UV exposure) can be performed on the photoresist film 120 using the mask 50. The exposure process can crosslink and harden the portions of the photoresist film 120 that correspond to the exposed areas.

[0065] 3, a developer may be used to remove the unexposed portions of the photoresist film 120. As a result, the exposed portions of the photoresist film 120 remain on the substrate 100 or the conductive film 110 to form a photoresist pattern 125. The photoresist pattern 125 may include a first photoresist pattern 123 and a second photoresist pattern 127 sequentially stacked on the substrate 100 or the conductive film 110.

[0066] Thereafter, a metal material may be filled into the space where the non-exposed portion is removed to form the wiring pattern 130. For example, the metal material may be formed by a plating process or a deposition process such as a sputtering process, a chemical vapor deposition process, or an atomic layer deposition process.

[0067] Referring to FIG. 4, the stripper composition according to the above exemplary embodiments may be dispensed or sprayed to remove the photoresist pattern 125.

[0068] According to an exemplary embodiment, the stripper solution composition can be used to start stripping or etching from the lower portion (e.g., the first photoresist pattern 123) of the photoresist pattern 125. As described above, ethanol can be used together with an alkaline compound and a polar organic solvent such as DMSO to rapidly bring the alkaline compound into contact with the resist pattern without loss due to volatilization, and to rapidly dissolve the removed resist components.

[0069] As a result, the photoresist pattern 125 can be sufficiently swollen and removed from the bottom, thereby achieving a lift-off type stripping process.

[0070] 5, the above-described stripping process can be continued to substantially remove the photoresist pattern 125. Since the above-described stripping solution composition has an improved resist dissolving power, the stripping process can be performed without substantially leaving any resist residue on the conductive layer 110 or the wiring pattern 130.

[0071] Also, as described with reference to FIG. 4, the peeling process is performed using the lift-off method, so that the photoresist pattern 125 can be substantially completely removed without leaving any residue of the underlying photoresist film.

[0072] As described above, the photoresist pattern 125 may be used as a partition for filling the metal wiring. In one embodiment, the photoresist pattern 125 may be used as an etching mask for etching the conductive layer 110. After the etching process using the photoresist pattern 125, a stripping process may be performed as described above.

[0073] Below, preferred embodiments are presented to aid in understanding the present invention. However, these embodiments are merely illustrative of the present invention and do not limit the scope of the appended claims. It will be apparent to those skilled in the art that various changes and modifications to the embodiments are possible within the scope of the scope and technical ideas of the present invention, and it is natural that such changes and modifications fall within the scope of the appended claims. EXAMPLES

[0074] Examples and Comparative Examples Based on the compositions and parts by weight shown in Table 1 below, resist stripping liquid compositions according to Examples and Comparative Examples were prepared.

[0075] [Table 1-1]

[0076] [Table 1-2]

[0077] [Table 1-3]

[0078] The compounds shown in Table 1 are as follows: TMAH: Tetramethylammonium hydroxide ETMAH: Ethyl trimethyl ammonium hydroxide BTMAH: Benzyltrimethylammonium hydroxide THEMAH: Tris(2-hydroxyethyl)methylammonium hydroxide MOPA: 3-Methoxypropylamine BOPA: 3-butoxypropylamine BMEA: Bis(2-methoxyethyl)amine EtOH: Ethanol MeOH: Methanol IPA: Isopropyl alcohol IBA: Isobutyl alcohol DMSO: Dimethyl sulfoxide DPSO: Diphenyl sulfoxide NMP: N-methyl-2-pyrrolidone PG: Propylene glycol HA: Hydroxylamine MEA: Monoethanolamine AEEA: N-(2-aminoethyl)ethanolamine PDA: Propylenediamine TPA: Tripropylamine

[0079] [Experimental Example 1] 1) Evaluation of resist stripping power A copper layer was formed on top of a silicon wafer by physical vapor deposition (PVD) process. A negative photoresist layer was double-coated on the copper layer to form a resist layer with a total thickness of 250 μm, as described in Figure 2. After UV curing and development, a copper pattern was formed by electrolytic plating in the non-exposed areas where the photoresist layer was removed, to prepare a test sample.

[0080] The prepared samples were cut to 3 cm x 3 cm, and the stripping solution compositions of the Examples and Comparative Examples were kept at a constant temperature of 70°C, after which the samples were immersed in the compositions, which were then stirred at 300 rpm, and the peeling strength was evaluated according to the following criteria.

[0081] <Evaluation criteria for peel strength> ◎: Resist stripping time is less than 10 minutes ○: Resist stripping time is 10 to 15 minutes less than △: Resist stripping time is 15 Minutes~ Less than 20 minutes X: Resist stripping time is 20 minutes or more

[0082] 2) Evaluation of resist dissolving power The samples prepared for evaluating the stripping power were immersed in the stripping solution compositions of the Examples and Comparative Examples, which were kept at a constant temperature of 70° C., and stirred at 300 rpm for 15 minutes. The remaining resist in the solution was filtered through filter paper, and the presence or absence of remaining resist on the filter paper was observed visually and with an optical microscope, and the dissolving power was evaluated according to the following criteria.

[0083] <Evaluation criteria for dissolving power> ○: No remaining amount is observed visually or by optical microscope △: No remaining amount is visible by visual inspection, but is visible under an optical microscope X: Remaining amount is visually observed

[0084] 3) Evaluation of metal corrosion The samples prepared for evaluating the peel strength were immersed for 30 minutes in the stripper compositions of the Examples and Comparative Examples, which were kept at a constant temperature of 70° C. Then, the corrosion of the surfaces of the PVD copper layer and the electroplated copper pattern was evaluated using a scanning electron microscope (SEM, Hitachi S-4700) according to the following criteria.

[0085] < Metal Corrosion Evaluation criteria> ◎: No surface corrosion observed ○: Some minor corrosion is observed △: Localized corrosion is observed X: Corrosion is observed over the entire surface.

[0086] The evaluation results are shown in Table 2 below.

[0087] [Table 2-1]

[0088] [Table 2-2]

[0089] Referring to Table 1, the compositions of Examples 1 to 15 contained ammonium hydroxy-based compounds, ethanol and DMSO in the specified contents, and provided improved stripping speed, resist dissolving power and corrosion prevention properties.

[0090] The compositions of Examples 16 to 22 further contained an amine-based compound not containing a hydroxyl group, and provided an improved stripping rate without decreasing the overall resist dissolving power.

[0091] With reference to the comparative examples, compositions lacking ammonium hydroxide or ethanol provided significantly reduced stripping rates and resist dissolving power compared to the examples.

[0092] In Comparative Examples 5 and 6, alcohols having 3 or more carbon atoms were used, and the stripping speed decreased and the residual resist was re-adsorbed due to insufficient dissolving power of the resist.

[0093] In Comparative Examples 7 and 8, the alcohol was omitted and a glycol-based solvent was added, but the resist peeling proceeded from the top, and the remaining resist was re-adsorbed.

[0094] In Comparative Example 9, an alkaline compound containing a hydroxyl group was added, but the removal rate decreased and the residual resist was re-adsorbed due to insufficient dissolving power of the resist.

[0095] In Comparative Example 10, the sulfoxide-based polar organic solvent was omitted, and the resist dissolving power decreased.

[0096] [Experimental Example 2] Evaluation of maintenance of peeling force The stripping liquid compositions of Example 5, Example 18 and Comparative Example 4 were prepared, heated to 65° C. or 70° C. and stored for 1, 2 or 3 hours, and then the resist stripping power and dissolving power were evaluated as described above.

[0097] The evaluation results are shown in Tables 3 and 4 below.

[0098] [Table 3]

[0099] [Table 4]

[0100] Referring to Tables 3 and 4, in the case of Comparative Example 4 using methanol, the initial peeling power and dissolving power were maintained, but it volatilized under high temperature process conditions, and the peeling power and dissolving power rapidly decreased over time. [Explanation of symbols]

[0101] 100: Substrate 110: Conductive film 120: Photoresist film 122: First photoresist film 124: Second photoresist film 123: First photoresist pattern 125: Photoresist pattern 127: Second photoresist pattern 130: Wiring pattern

Claims

1. an alkaline compound including an ammonium hydroxide compound; Ethanol, a polar organic solvent containing a sulfoxide compound; deionized water, The resist stripping liquid composition has a polar organic solvent content of 55 to 95 wt % based on the total weight of the resist stripping liquid composition, and a difference between the content of the ammonium hydroxide compound and the content of the deionized water is 2 wt % or less.

2. The resist stripping liquid composition according to claim 1 , wherein the polar organic solvent comprises dimethyl sulfoxide.

3. The resist stripping solution composition according to claim 1 , wherein the alkaline compound further comprises an amine compound.

4. The resist stripping solution composition according to claim 3 , wherein the amine compound comprises an alkoxyalkylamine.

5. Relative to the total weight of the resist stripping liquid composition, 0.1 to 5% by weight of the ammonium hydroxide compound; 2. The resist stripping liquid composition according to claim 1, further comprising 4 to 40% by weight of ethanol.

6. 6. The resist stripping solution composition according to claim 5, wherein the content of said deionized water in the total weight of said resist stripping solution composition is 0.1 to 5% by weight.

7. forming a photoresist pattern on a substrate; forming a conductive pattern using the photoresist pattern; and removing the photoresist pattern by using the resist remover composition according to claim 1.

8. 8. The method of claim 7, wherein the step of removing the photoresist pattern comprises removing a lower portion of the photoresist pattern with the resist stripper composition.

9. 9. The method of claim 8, wherein the photoresist pattern includes a first photoresist pattern and a second photoresist pattern sequentially formed on the substrate, and the first photoresist pattern is removed by the resist stripper composition.

10. The pattern forming method according to claim 7 , further comprising the step of forming a conductive layer on the substrate before forming the photoresist pattern.

11. 8. The pattern forming method according to claim 7, wherein a plurality of the photoresist patterns are formed, and the step of forming the conductive pattern includes filling a conductive material between adjacent ones of the photoresist patterns.

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