A developer composition for integrated circuits

Abstract

The application discloses a developing solution composition for integrated circuits and belongs to the field of wet electronic chemicals. According to the sum of mass percentages being 100%, the mass percentages of the components in the composition are as follows: 1.0-5.0% of inorganic alkali, 1.0-3.0% of developing promoter, 0.1-1.0% of penetrating agent, 0.1-2.0% of non-ionic Gemini surfactant, and the balance of water. The specific non-ionic Gemini surfactant is used in the application, so that the obtained developing solution composition has excellent developing performance, can effectively develop photoresists with slight different exposure amounts in the same developing time, avoids edge residue, and can ensure that the photoresists are completely dissolved in the developing solution and will not be re-stuck on the substrate, thereby improving product yield, and the developing solution composition has excellent wetting property, low irritancy, easy rinsing, easy degradation and other characteristics, is environment-friendly, and meets environmental protection requirements.

Description

Technical Field

[0001] This invention belongs to the field of wet electronic chemicals, specifically relating to a developer composition used in the foundry and packaging process of integrated circuit chips. Background Technology

[0002] Chip manufacturing involves all aspects of the national economy and national security, making it a strategic industry. Photolithography, the process of forming designed circuit patterns on the wafer surface, is one of the most crucial steps in semiconductor manufacturing and currently a bottleneck limiting my country's semiconductor manufacturing capabilities. Photolithography typically consists of two steps: First, exposure and development alter the properties and structure of the photoresist, forming the circuit pattern on the photoresist layer and enabling its transfer. Then, etching or deposition is performed on the areas of the wafer surface not covered by the photoresist, completing the fabrication of the circuit pattern. Development is a core step in photolithography, revealing the latent image in the exposed photoresist to form the final lithographic pattern. The quality of the developer and the process directly determine the precision, sidewall morphology, and defect level of the lithographic pattern, which is crucial to the yield and performance of integrated circuits.

[0003] As integrated circuit manufacturing processes advance to the nanoscale (e.g., 7nm, 5nm, 3nm), unprecedented challenges have arisen for developing technologies. The smaller the pattern size, the more sensitive it is to defects generated during development (including developer residue and watermarks). Developer residue may originate from the slight dissolution of the developer with photoresist byproducts; watermarks occur during the deionized water rinsing and drying stages after development, caused by the surface tension of water pulling between nanoscale patterns, leading to pattern collapse or contamination. In the manufacturing process, even minute deviations in the size or position of any layer's pattern (i.e., edge placement errors) can ultimately affect device performance. Therefore, developers with higher dissolution rate contrast are needed to ensure sharp boundaries between exposed and unexposed areas, resulting in photoresist patterns with clear outlines and low linewidth roughness. Furthermore, due to light irradiation issues during photoresist exposure, the beam cannot be guaranteed to be perfectly perpendicular. Under the same exposure level, the exposure levels at the edges of the photoresist will vary slightly, requiring a high dissolution rate from the developer to ensure uniform dissolution. Invention patent (application number 202410848708.6) discloses a developer solution, its preparation method, and its application. The developer solution's raw material composition includes 0.5% tetramethylammonium hydroxide; 1%-10% corrosion inhibitor; and 1%-10% stabilizer. While it can significantly improve the corrosion rate and effective lifespan of aluminum, it cannot reduce surface tension and has poor effects on development uniformity. Furthermore, the use of TMAH results in high toxicity, low alkalinity, and no significant improvement in development speed. Invention patent (application number 202510104847.2) discloses a developer solution whose synthetic raw materials include modified surfactants, a weakly alkaline mixture, modified defoamers, composite dispersants, modified chelating agents, organic solvents, and deionized water. It improves development effect and efficiency, but the system does not significantly reduce surface tension and has no good effect on linewidth accuracy or photoresist solubility. Summary of the Invention

[0004] To overcome the problems of slow development speed, uneven development, and insufficient solubility of photoresist in the developer solution in existing TMAH solutions, this invention provides a developer composition for integrated circuits. By adding a specific nonionic Gemini surfactant, it ensures uniform development while maintaining a satisfactory development speed, thus improving the development rate. It effectively develops photoresists with slight exposure differences within the same development time, avoiding edge residue. Simultaneously, it ensures complete dissolution of the photoresist in the developer solution, preventing it from adhering to the substrate, corroding metal electrodes, or introducing other metallic impurities, thereby improving product yield. Furthermore, it possesses excellent wettability, low irritation, easy rinsing, and easy degradation properties, making it environmentally friendly and meeting environmental protection requirements.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A developer composition for integrated circuits, comprising, by weight percentage (totaling 100%), the components and their weight percentages as follows: inorganic alkali 1.0-5.0%, developer accelerator 1.0-3.0%, penetrant 0.1-1.0%, nonionic Gemini surfactant 0.1-2.0%, with the balance being water.

[0006] Furthermore, the inorganic base is selected from any one or more of potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

[0007] Furthermore, the developing accelerator is selected from any one or more of potassium metaborate, sodium metaborate, sodium tetraborate, potassium tetraborate, sodium pyroborate, potassium pyroborate, potassium phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, trisodium phosphate, sodium citrate, ammonia, and disodium ethylenediaminetetraacetate.

[0008] Furthermore, the penetrant is selected from any one or more of sodium dodecylbenzene sulfonate, succinate sulfonate, sodium diisooctyl sulfosuccinate, sodium dodecyl sulfate, fatty alcohol polyoxyethylene ether, fatty alcohol polyoxyethylene ester, dodecyl dimethyl betaine, alkyl aminopropionate, etc.

[0009] Furthermore, the general formula of the nonionic Gemini structure is as follows: Where a and b are integers from 1 to 10.

[0010] The preparation of this nonionic Gemini surfactant includes the following steps: (1) Synthesis of intermediate I Dodecenyl succinic anhydride and lysine were dissolved in acetone, and 4-dimethylaminopyridine (DMAP) was added under stirring at room temperature. The temperature was then raised to 40 °C, and the reaction was carried out under stirring. After the reaction was complete, the solvent was removed by vacuum distillation, and the product was separated by column chromatography to obtain intermediate I. (2) Synthesis of intermediate II Intermediate I was mixed with catalyst KOH and dehydrated under vacuum at 110-120°C for 1 hour under nitrogen. Then, propylene oxide was added at 110-115°C (the addition was controlled to be completed within 3 hours), and the aging reaction was carried out under pressure <0.4 MPa until the pressure reached 0 MPa. Ethylene oxide was then added at 110-115°C (the addition was controlled to be completed within 3 hours), and the aging reaction was continued under pressure <0.4 MPa until the pressure reached 0 MPa. The mixture was then cooled and bubbled to degas for 1 hour. When the temperature dropped to 80°C, glacial acetic acid was added to neutralize the pH to 7. The mixture was then discharged to obtain intermediate II.

[0011] (3) Synthesis of nonionic Gemini surfactants Intermediate II, NaOH, and tetrabutylammonium chloride were stirred evenly in ethylene glycol dimethyl ether, and then 1,4-dichlorobutane was added dropwise. The reaction system was refluxed at 85°C for 24 h. After removing the solvent by rotary evaporation, the crude product was washed with ethyl acetate to obtain the nonionic Gemini surfactant.

[0012] Furthermore, the molar ratio of dodecenyl succinic anhydride, lysine and 4-dimethylaminopyridine used in step (1) is 12:10:1.

[0013] Furthermore, the column chromatography separation in step (1) uses a petroleum ether / ethyl acetate (PE / EA) mixture with a volume ratio of 85:15 as the eluent.

[0014] Furthermore, the molar ratio of intermediate I, KOH, propylene oxide and ethylene oxide used in step (2) is 1:0.003:(1~10):(1~10).

[0015] Furthermore, the molar ratio of intermediate II, NaOH, tetrabutylammonium chloride and 1,4-dichlorobutane used in step (3) is 5:3:0.05:5.3.

[0016] Furthermore, the water is high-purity water with a resistivity greater than 18 MΩ / cm.

[0017] Furthermore, the method for preparing the developer composition is to add an inorganic alkali and a developer accelerator to water, stir at 200 rpm to form a homogeneous system, then add a penetrant and a Gemini surfactant, and continue stirring to obtain a homogeneous, stable, clear and transparent solution.

[0018] The significant advantages of this invention are: The nonionic Gemini surfactant used in this invention possesses a low critical micelle concentration (CMC), low foaming properties, and good wettability. Gemini surfactants simultaneously possess two hydrophilic groups and two hydrophobic groups, which facilitates intermolecular aggregation to form micelles, resulting in a lower CMC and stronger interfacial adsorption. The steric hindrance effect of the hydrophilic chain effectively inhibits the close arrangement of surfactant molecules at the interface, allowing one end of the surfactant to form hydrogen bonds with water molecules, while the other end can combine with photoresist molecules. This reduces the interfacial tension between the photoresist and water, thereby endowing the material with low foaming and rapid wetting and penetration capabilities. This ensures rapid dissolution of the photoresist during development, increasing the development speed without significant foam contamination of the wafer, and ensuring effective development of photoresists with slight exposure differences at the same development time, avoiding edge residue. Simultaneously, the chemical bonding of its linking groups does not destroy its hydrophilicity, giving the surfactant excellent water solubility and allowing it to dissolve in alkaline systems. Furthermore, its PO-EO structure not only extends the length of the hydrophobic chain but also induces molecular orientation at the interface through the methyl side chain of the PO chain, precisely controlling the hydrophilic-hydrophobic balance of the surfactant. The presence of ethylene oxide in the surfactant contributes to the uniformity of development and possesses excellent cleaning capabilities. It emulsifies the photoresist, increasing its solubility in the developer and preventing photoresist particles from adhering to the substrate and causing defects. The lone pair electrons on the nitrogen atom in the amide group can act as electron donors, forming coordinate bonds with the empty d orbitals of atoms on the metal surface. This creates a dense, hydrophobic monomolecular adsorption film on the metal surface, which does not corrode the metal electrodes. Furthermore, this nonionic surfactant has low metal impurity content, does not introduce other metal ions, and does not contaminate the chip, meeting the requirements for integrated circuit applications.

[0019] In summary, the nonionic Gemini surfactant used in this invention has excellent developing performance, can exist stably in alkaline solutions, can effectively reduce surface tension, can ensure uniform development during the development process, improve the development rate, and can effectively develop photoresists with slight differences in exposure in the same development time, avoiding edge residue. It can also ensure that the photoresist is completely dissolved in the developer and will not stick to the substrate, thus improving product yield. It will not corrode metal electrodes and also has excellent wettability, low irritation, easy rinsing, and easy degradation properties, making it environmentally friendly and meeting environmental protection requirements. Detailed Implementation

[0020] A positive photoresist developer composition for integrated circuits, wherein the components and their mass percentages, based on a total mass percentage of 100%, are as follows: inorganic alkali 1.0-5.0%, developer accelerator 1.0-3.0%, penetrant 0.1-1.0%, nonionic Gemini surfactant 0.1-2.0%, and the balance being water.

[0021] The inorganic base is selected from any one or more of potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

[0022] The developing accelerator is selected from any one or more of the following: potassium metaborate, sodium metaborate, sodium tetraborate, potassium tetraborate, sodium pyroborate, potassium pyroborate, potassium phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, trisodium phosphate, sodium citrate, ammonia, and disodium ethylenediaminetetraacetate.

[0023] The penetrant is selected from any one or more of the following: sodium dodecylbenzenesulfonate, succinate sulfonate, sodium diisooctyl sulfosuccinate, sodium dodecyl sulfate, fatty alcohol polyoxyethylene ether, fatty alcohol polyoxyethylene ester, dodecyl dimethyl betaine, alkyl aminopropionate, etc.

[0024] The general structural formula of the nonionic Gemini surfactant is as follows: , where a and b are integers from 1 to 10.

[0025] The water is high-purity water with a resistivity greater than 18 MΩ / cm.

[0026] To make the content of this invention easier to understand, the technical solution of this invention will be further described below with reference to specific embodiments, but this invention is not limited thereto.

[0027] Examples and Comparative Examples The developer compositions of the examples and comparative examples were prepared according to the composition and mass percentage shown in Table 1.

[0028] Table 1 The preparation method of nonionic Gemini surfactant A is as follows: Step 1: Synthesis of Intermediate I Dodecenylsuccinic anhydride (12.0 mmol) and lysine (10.0 mmol) were dissolved in acetone (50.0 mL). 4-Dimethylaminopyridine (DMAP, 1.0 mmol) was added under stirring at room temperature, and the mixture was then heated to 40 °C. The reaction was carried out by stirring, and the reaction was detected by thin-layer chromatography (TLC) (detection was performed every half hour during the reaction, and the plates were climbed using petroleum ether / ethyl acetate (85:15, v / v), and then baked until only two substances were visible on the plate, indicating that the reaction was complete). After the reaction was complete, the solvent was evaporated under reduced pressure, and column chromatography was performed using petroleum ether / ethyl acetate (85:15, v / v) as the eluent to obtain intermediate I.

[0029] Step 2: Synthesis of Intermediate II Intermediate I (8 mmol) and catalyst KOH (0.024 mmol, 0.15 wt% purity) were added to a high-temperature, high-pressure reactor. The reactor was sealed and purged twice with nitrogen. After the reactor temperature reached 110–120 °C, a vacuum was applied for 1 hour to remove moisture. Then, the reactor temperature was maintained at 110–115 °C, and propylene oxide (24 mmol) was added, controlling the pressure below 0.4 MPa. The addition was completed over 3 hours, and the reaction was continued until the pressure reached 0 MPa. Next, the reactor temperature was maintained at 110–115 °C, and ethylene oxide (24 mmol) was introduced, controlling the pressure below 0.4 MPa. The addition was completed over 3 hours, and the reaction was continued until the pressure reached 0 MPa. The reactor was then cooled and degassed by bubbling for 1 hour. When the temperature dropped to 80 °C, glacial acetic acid was added to neutralize to pH 7. The product was then discharged to obtain intermediate II.

[0030] Step 3: Synthesis of nonionic Gemini surfactant A In a three-necked flask, intermediate II (5 mmol), 50% NaOH solution (0.24 g), and tetrabutylammonium chloride (0.05 mmol) were dissolved in ethylene glycol dimethyl ether (120 mL) and stirred until homogeneous. Then, 1,4-dichlorobutane (5.3 mmol) was added dropwise. The reaction system was refluxed at 85 °C for 24 h. After removing the solvent by rotary evaporation, the crude product was washed with ethyl acetate to obtain the final product.

[0031] According to FTIR analysis, the range is 2858–2959 cm⁻¹. -1 The positions 1712 and 1716 cm correspond to the stretching vibrations of long alkyl chains in the molecular structure; -1 The peak at 1648 cm⁻¹ is attributed to the stretching vibration of the carbonyl group in the ester bond. -1 The peak at 1173–1176 cm⁻¹ is attributed to the stretching vibration of the carbonyl group in the amide bond. -1 There is a set of relatively strong peaks at 1352 cm⁻¹, which are attributed to the stretching vibrations of CO in ether, amide, and ester bonds. -1 The nearby location corresponds to the "-[CH2-CH2-O-]-" segment containing the "-CH2" group, while 1101 cm -1 The nearby location represents the COC vibration.

[0032] according to 1 H NMR ( d Analysis using DMSO (300 MHz) yielded a chemical shift of ( d):8.76(s, 4H, -NH2);5.40(s, 4H, -OH);6.01(s, 2H, -OH);4.32(m, 4H, O-CH2-C);4.53(s, 4H,O-CH2-C);3.70(m, 8H, CH2-CH2-OH);3.60(m, 10H, CH2-CH-O);3.54(m, 24H, CH2-CH2-O);3.18(m,8H, N-CH2-CH2);2.85(m, 4H, CO-CH2-C);1.32(d, 36H, CH3-CH);1.26(q, 32H, C-CH2-CH2);0.88(t, 6H, -CH3).

[0033] according to 13 C NMR ( d Analysis using DMSO (300 MHz) yielded a chemical shift of ( d ):207.3;171.5;129.5;127.6;78.4;77.8;77.0;75.4;70.7;67.9;61.3;52.3;49.7;37.6;31.9;29.6;17.6;14.1.

[0034] According to HRMS analysis, its molecular formula is C 110 H 210 N4O 34 , m / z: 2132.49.

[0035] The above data proves that the nonionic Gemini surfactant A with a=3 and b=3 was successfully synthesized.

[0036] The preparation of nonionic Gemini surfactant B involved dissolving intermediate I (5 mmol), 50% NaOH solution (0.24 g), and tetrabutylammonium chloride (0.05 mmol) in ethylene glycol dimethyl ether (120 mL) in a three-necked flask, stirring until homogeneous, and then adding 1,4-dichlorobutane (5.3 mmol) dropwise. The reaction system was refluxed at 85 °C for 24 h. After removing the solvent by rotary evaporation, the crude product was washed with ethyl acetate to obtain the final product.

[0037] according to 13 C NMR ( d Analysis using DMSO (300 MHz) yielded a chemical shift of ( d ):174.7;171.5;127.6;55.8;50.0;44.2;38.8;33.3;31.9;29.7;22.7;14.1.

[0038] According to HRMS analysis, its molecular formula is C 48 H 86 N4O 10 , m / z: 878.63.

[0039] Its structural formula is as follows: .

[0040] The following tests were conducted to evaluate the developing effect of the developing solution compositions prepared in the examples and comparative examples on integrated circuit photoresists.

[0041] The testing method is as follows: I. Basic Performance Testing 1. Prepare developing solutions according to different formulas and compare whether the chemical solution systems are clear, transparent, and homogeneous. ○: Clear and transparent; ×: Turbid precipitation.

[0042] 2. Prepare developing solutions according to different formulas and compare whether the surface tension of the chemical solution system meets the requirements. ○: Surface tension <30mN / m; ×: Surface tension > 30mN / m.

[0043] II. Development Performance Testing Positive photoresist is spin-coated onto a clean 6-inch wafer at 450 rpm, then cured in an oven at 85°C for 120 seconds. After cooling to 23°C, a photomask pattern with a specific linewidth is transferred onto the sample wafer using an exposure machine, thus obtaining a photoresist sample wafer of a certain thickness.

[0044] Adjust the developer temperature to 23℃, spray the developer onto the sample slide at a constant pressure using an oscillating motion for 5 seconds, let it stand for 60 seconds, then spray with developer for another 10 seconds. After development, rinse with high-purity water, dry with nitrogen, and bake in a 130℃ oven for 30 minutes. Observe under a microscope: 1. Is the developed pattern clear? 2. Are there any photoresist residues? 3. Is the line width up to standard? ○: CD error <1%; ×: CD error > 1%.

[0045] 4. Is there corrosion on the wafer? The results are shown in Table 2.

[0046] Table 2 As can be seen from Tables 1 and 2, the developer composition prepared in the examples ensures system stability and low surface tension. During development, the image is clear and uniform with minimal linewidth variation. It effectively develops photoresists with slight exposure differences within the same development time, avoiding photoresist residue at the edges. The photoresist is completely dissolved in the developer and will not re-adhere to the substrate, resulting in high yield. It does not corrode metal electrodes, improving production efficiency and saving costs.

[0047] Compared with Example 1, Comparative Example 1 uses surfactant B obtained by direct reaction of intermediate I and dichlorobutane. The surface tension of its developer can be reduced, but its emulsification ability for photoresist is extremely poor. It cannot dissolve the photoresist uniformly and effectively, resulting in serious photoresist residue and unqualified linewidth.

[0048] Compared to Example 2, Comparative Example 2 did not add a development accelerator, which resulted in a significant decrease in development speed, slight photoresist residue, and excessively large linewidth.

[0049] Compared with Example 3, Comparative Example 3 did not add surfactant, and its developer had a larger surface tension, poor photoresist dissolution ability, and serious photoresist residue and wafer corrosion problems.

[0050] Compared with Example 4, Comparative Example 4 selected TX-7 as the surfactant and increased its addition amount. Its developer has good stability, low surface tension, and good emulsification and dispersibility for photoresist. However, it has insufficient photoresist dissolution ability, poor development speed, slight photoresist residue, and wafer corrosion problems.

[0051] Compared with Example 5, Comparative Example 5 used TMAH instead of inorganic alkali. Since TMAH has a weaker alkalinity, it simultaneously increased the surfactant content, resulting in a system with good stability. However, the development speed was still relatively slow, and there was photoresist residue.

[0052] Compared with Example 6, Comparative Example 6 uses the generated intermediate II as a surfactant. Its surface tension can meet the requirements, but its emulsification ability for photoresist is insufficient. It cannot effectively disperse and dissolve the photoresist, resulting in photoresist residue on the wafer, unqualified development linewidth, and significant corrosion of the wafer.

[0053] As can be seen from the above, by adding nonionic Gemini surfactant A and adjusting the content of inorganic alkali, developer, and penetrant, the development performance of the composition can be significantly improved, making it compatible with most photoresists and stabilizing the development speed. Furthermore, it possesses excellent emulsifying properties, improving the accuracy of the developed pattern. It can effectively develop photoresists with slight differences in exposure at the same development time, avoiding edge residue. It also ensures that the photoresist is completely dissolved in the developer, preventing it from adhering to the substrate, thus improving yield, and it will not corrode the metal electrodes. In summary, the addition of the nonionic Gemini surfactant used in this invention stabilizes the system and reduces surface tension. Simultaneously, it possesses excellent developing performance, stabilizing linewidth variations, exhibiting strong emulsification properties for photoresist without leaving residue, resulting in high pattern clarity. It does not corrode the wafer and effectively solves the problem of developer residue due to slight exposure differences, avoiding photoresist residue. Furthermore, it significantly improves the solubility of the developer in photoresist, increasing yield. Moreover, it exhibits excellent wetting properties, low irritation, easy rinsing, and easy degradation, making it environmentally friendly and meeting environmental protection requirements.

[0054] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be included in the scope of the present invention.

Claims

1. A developer composition for integrated circuits, characterized in that, Based on a total mass percentage of 100%, the components in the composition and their respective mass percentages are as follows: inorganic alkali 1.0-5.0%, developer accelerator 1.0-3.0%, penetrant 0.1-1.0%, nonionic Gemini surfactant 0.1-2.0%, and the balance being water; The general structural formula of the nonionic Gemini surfactant is as follows: , where a and b are integers from 1 to 10.

2. The developer composition for integrated circuits according to claim 1, characterized in that, The inorganic base is selected from any one or more of potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

3. The developer composition for integrated circuits according to claim 1, characterized in that, The developing accelerator is selected from any one or more of potassium metaborate, sodium metaborate, sodium tetraborate, potassium tetraborate, sodium pyroborate, potassium pyroborate, potassium phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, trisodium phosphate, sodium citrate, ammonia, and disodium ethylenediaminetetraacetate.

4. The developer composition for integrated circuits according to claim 1, characterized in that, The penetrant is selected from any one or more of sodium dodecylbenzenesulfonate, succinate sulfonate, sodium diisooctyl sulfosuccinate, sodium dodecyl sulfate, fatty alcohol polyoxyethylene ether, fatty alcohol polyoxyethylene ester, dodecyl dimethyl betaine, and alkyl aminopropionate.

5. A developer composition for integrated circuits according to claim 1, characterized in that, The water is high-purity water with a resistivity greater than 18 MΩ / cm.

6. A developer composition for integrated circuits according to claim 1, characterized in that, The method for preparing the composition is to add an inorganic alkali and a developer accelerator to water, stir to form a homogeneous system, then add a penetrant and a nonionic Gemini surfactant, and continue stirring to obtain a homogeneous, stable, clear and transparent solution.

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