Environment-friendly developing agent with metal protection capability

Abstract

The invention discloses an environment-friendly developing agent with metal protection capability. The environment-friendly developing agent is prepared from the following components in percentage by weight: 4-8% of organic amine, 6-20% of an environment-friendly solvent, 1-4% of a chelating agent, 0.5-2% of a surfactant, 0.1-0.5% of polylysine and the balance of water. The environment-friendly developing agent with the metal protection capability provided by the invention can be used for developing photoresist, is safe and non-corrosive to metal substrates such as copper and stainless steel, does not influence the dimensional accuracy, is safe to human bodies and environments, is degradable in components, and is simple and convenient in preparation process.

Description

Technical Field

[0001] The present invention relates to the technical field of precision metal surface treatment, and particularly relates to an environmentally friendly developer with metal protection ability. Background Art

[0002] In the precision metal etching process, photoresist development is the core process of pattern transfer. The developer selectively dissolves the photoresist in the exposed area to form a micro-nano scale resist pattern consistent with the design, which directly affects the accuracy of subsequent etching or electroplating. Currently, a 0.8 - 1.2% sodium carbonate solution is generally used as the alkaline developer in the industry, and its mechanism of action is based on the dissociation and dissolution of carboxylic acid groups in the photoresist under alkaline conditions.

[0003] The sodium carbonate developer is sensitive to process parameters. When the environmental temperature fluctuates or the concentration deviation is slightly large, the change rate of the development rate is relatively high, which easily leads to underdevelopment or overdevelopment. Especially for dense patterns with a line width ≤ 10μm, development residues or rough sidewalls are likely to occur. The strong penetration of carbonate ions between photoresist molecules will cause the swelling of the unexposed area of the photoresist film. In the subsequent etching process, the adhesion between the swollen photoresist film and the substrate decreases, resulting in the defect of edge lift-off. When carbonate in sodium carbonate encounters a small amount of copper ions in water, basic copper carbonate can be formed, which can slowly corrode copper and may pose a hidden danger in the increasingly precise pattern operations. When treating the sodium carbonate developer, hydrochloric acid needs to be added for neutralization, which increases the treatment cost and generates CO2 emissions, not meeting the requirements of the ISO 14067 carbon footprint standard.

[0004] Currently, other patents using organic amines as the base source have been disclosed, such as CN103728845B, which uses a combination of organic amines and non-ionic surfactants and has applications in the field of flat panel displays. However, the application field of this patent is the color filter layer in the display, lacking in the application fields that require metal protection, and there is a possibility of pattern deformation caused by metal corrosion in scenarios such as metal mask etching. Summary of the Invention

[0005] To overcome the above technical problems existing in the prior art, the present invention provides an environmentally friendly developer with metal protection ability, which can achieve the development of photoresist, and at the same time is safe and non-corrosive to metal substrates such as copper and stainless steel, without affecting the dimensional accuracy.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows: An environmentally friendly developer with metal protection ability, the cleaning agent includes the following components by weight percentage of raw materials: 4 - 8% organic amine, 6 - 20% environmentally friendly solvent, 1 - 4% chelating agent, 0.5 - 2% surfactant, 0.1 - 0.5% polylysine, and the balance is water.

[0007] Furthermore, the organic amine is at least one of monoethanolamine, diethanolamine, triethanolamine, diethylene glycol amine, isopropanolamine, diisopropanolamine, 2-amino-2-methyl-1-propanol.

[0008] Furthermore, the environmentally friendly solvent is at least one of γ-valerolactone, dimethyl isosorbide, and triacetin.

[0009] Furthermore, the chelating agent is at least one of sodium citrate, potassium sodium tartrate, sodium malate, sodium gluconate, and trisodium methylglycinediacetate.

[0010] Furthermore, the surfactant is rhamnolipid or a mixture thereof with other biodegradable surfactants such as alkyl glycoside, sucrose fatty acid ester, polyoxyethylene ether sulfate, etc. Among them, the rhamnolipid is at least one of monorhamnolipid and dirhamnolipid, and the other surfactants mixed with rhamnolipid are biodegradable surfactants, including but not limited to alkyl glycoside, sucrose fatty acid ester, polyoxyethylene ether sulfate, etc.

[0011] Furthermore, the degree of polymerization of the polylysine is 25 - 30.

[0012] The present invention uses a biodegradable organic amine as the base source, avoiding the problems of unstable development rate and pattern edge peeling caused by the use of sodium carbonate. In view of the fact that the alkalinity of the organic amine is weaker than that of sodium carbonate, an environmentally friendly solvent and a chelating agent are selected to assist in the dissolution of the development area. At the same time, the chelating agent can also clean the granular residues at the pattern edge and improve the morphology. Among them, the surfactant is mainly used to improve the morphology of the pattern edge. At the same time, the rhamnolipid selected in the present invention contains a large number of hydroxyl groups, which can adhere to the surface of the metal substrate to provide corrosion inhibition protection; the selected additive polylysine contains a large number of free amino groups and also has certain surface activity, and can spontaneously adsorb at the phase interface, so it can also adhere to the surface of the metal substrate to provide protection, expanding the range of metal types that can be protected from corrosion.

[0013] All the substances selected in the present invention are biodegradable substances, meeting the requirements of environmental protection.

[0014] When selecting the environmentally friendly solvent in the present invention, low flash point solvents such as ethyl lactate and butyl lactate are excluded, and substances that are prone to hydrolysis under weak alkaline conditions are also avoided as much as possible, ensuring safety and stability.

[0015] In the present invention, film-forming organic corrosion inhibitors such as benzotriazole, which are widely used, are not selected for metal corrosion inhibition. This is mainly because it is difficult to elute such substances after they form a film covering the surface of the metal substrate, which is likely to have an adverse impact on subsequent processes. At the same time, the present invention uses a variety of organic additives to assist in the dissolution of the exposure photoresist. The developer has a weaker alkalinity than the sodium carbonate developer, and the pH level of the solution itself has a weaker corrosive effect on the metal. Some organic amines accelerate the corrosion of some metals through coordination. Selecting a protective agent with a reversible physical adsorption mechanism can, on the one hand, use the hydrophobic layer to block the penetration of organic amine molecules, and on the other hand, its hydrophilic group forms a strong hydrogen bond with the organic amine, preventing the free organic amine molecules from directly contacting the metal surface. Therefore, the protective ability can already meet the requirements, and at the same time, it can also bring the advantage of low residue.

[0016] Advantages of the present invention: 1. Using biodegradable organic amines to replace sodium carbonate as the alkali source, and adding an environmentally friendly solvent to improve the development effect of the organic amine. While solving the performance problems of sodium carbonate during development, it has been improved in terms of environmental protection, and the development effect is stronger than that of a simple organic amine system; 2. Using the compound of polylysine and rhamnolipid has a good corrosion inhibition and protection effect on the metal substrate and can be used in scenarios where it is necessary to keep the metal from being eroded; 3. Some components of the present invention simultaneously play multiple functions in the cleaning agent. For example, rhamnolipid has the function of regulating the surface and interface morphology of the surfactant and can also provide protection for the metal surface; the chelating agent can improve the development rate while cleaning the pattern surface and reducing the burrs at the pattern edges. By using the above-mentioned multifunctional components, the present invention achieves the effect of reducing the types and amounts of the formula raw material components, and realizes the purpose of simplifying the production process and reducing costs; 4. The present invention obtains the development and metal protection effects through the compounding of multiple components; does not use strong alkalis, the reagent properties are relatively mild, and it is more secure for the operators; all the formula components are selected from biodegradable raw materials, do not contain phosphorus, and the preparation process is simple and convenient. Specific embodiments

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the embodiments. Example 1:

[0018] An environmentally friendly developer with metal protection ability, comprising the following raw materials in weight percentages: monoethanolamine 5%, γ-valerolactone 8%, sodium citrate 2%, monorhamnolipid 1%, polylysine 0.15%, and the balance is water. Example 2:

[0019] An environment-friendly developer with metal protection ability, comprising raw materials in the following weight percentages: diethanolamine 4%, dimethyl isosorbide 10%, potassium sodium tartrate 1%, monorhamnolipid 1.2%, polylysine 0.1%, and the balance being water. Example 3:

[0020] An environment-friendly developer with metal protection ability, comprising raw materials in the following weight percentages: isopropanolamine 5%, γ-valerolactone 9%, sodium gluconate 1.5%, monorhamnolipid 1%, polylysine 0.12%, and the balance being water. Example 4:

[0021] An environment-friendly developer with metal protection ability, comprising raw materials in the following weight percentages: diisopropanolamine 6%, triacetin 10%, trisodium methylglycinediacetate 1.2%, dirhamnolipid 0.8%, polylysine 0.15%, and the balance being water. Example 5:

[0022] An environment-friendly developer with metal protection ability, comprising raw materials in the following weight percentages: 2-amino-2-methyl-1-propanol 4%, dimethyl isosorbide 9%, sodium malate 1.5%, monorhamnolipid 1.2%, polylysine 0.18%, and the balance being water. Example 6:

[0023] An environment-friendly developer with metal protection ability, comprising raw materials in the following weight percentages: monoethanolamine 4%, triethanolamine 1%, triacetin 8%, sodium citrate 1%, dirhamnolipid 1.2%, polylysine 0.1%, and the balance being water. Example 7:

[0024] An environment-friendly developer with metal protection ability, comprising raw materials in the following weight percentages: 2-amino-2-methyl-1-propanol 2%, triethanolamine 4%, dimethyl isosorbide 9%, trisodium methylglycinediacetate 2%, monorhamnolipid 1.5%, polylysine 0.1%, and the balance being water. Example 8:

[0025] An environment-friendly developer with metal protection ability, comprising raw materials in the following weight percentages: isopropanolamine 3%, diisopropanolamine 3%, γ-valerolactone 12%, sodium citrate 1.5%, monorhamnolipid 1%, polylysine 0.12%, and the balance being water.

[0026] Comparative Example 1: A developer, comprising raw materials in the following weight percentages: sodium carbonate 1%, and the balance being water.

[0027] Comparative Example 2: A developer, comprising raw materials in the following weight percentages: sodium carbonate 1%, rhamnolipid 1%, and the balance being water.

[0028] Comparative Example 3: A developer, comprising raw materials in the following weight percentages: sodium carbonate 1%, polylysine 0.12%, and the balance being water Comparative Example 4: A developer, comprising raw materials in the following weight percentages: monoethanolamine 6%, and the balance being water.

[0029] Comparative Example 5: A developer, comprising raw materials in the following weight percentages: monoethanolamine 5%, γ-valerolactone 8%, sodium citrate 1.5%, and the balance being water.

[0030] Test Example 1: The developers obtained in Examples 1-8 and Comparative Examples 1-5 were examined for their developing performance. A stainless steel workpiece with a photoresist covered with an exposed pattern was taken. After removing the protective film, the workpiece was immersed in the above-mentioned developer and ultrasonically soaked at 30°C for 45 seconds. After rinsing and drying, the developing effect was examined. The results are shown in Table 1: Table 1 Comparison of Developing Effects

[0031] As can be seen from Table 1, Examples 1 to 8 had good developing effects, with clear patterns and the phenomenon of edge peeling being suppressed, and no peeling occurred in the areas that should not be dissolved and peeled. In Comparative Examples 1-3, edge peeling of the pattern occurred, and partial peeling effects also occurred in the areas that needed photoresist protection; in Comparative Example 4, only organic amine was used for development, and the developing rate was slow, unable to meet the requirements; in Comparative Example 5, a solvent and a chelating agent for assisting development were added on the basis of Comparative Example 4, and the peeling performance was relatively close to that of the examples.

[0032] Test Example 2: Safety test of metal substrates. Clean and non-corrosive copper test pieces and stainless steel negatives after degumming in the test examples were taken and immersed in the developers of Examples 1-8 and Comparative Examples 1-5 respectively. They were soaked in an open container at a constant temperature of 50°C for 2 h, and the appearance of the copper test pieces and metal negatives was observed to measure the safety of the developer for metal substrates. The results are shown in Table 2: Table 2 Results of Safety Test of Metal Substrates

[0033] As can be seen from the results in Table 2, the developer provided by the present invention is safe and non-corrosive to metal substrates such as copper; Comparative Examples 1, 4, and 5 without corrosion inhibitors have slight erosion on copper and stainless steel metal substrates; Comparative Examples 2 and 3 with corrosion inhibitors have certain corrosion inhibition ability.

[0034] Some components of the present developer play multiple functions simultaneously in the cleaning agent. For example, rhamnolipid has the regulating effect of a surfactant on the surface and interface morphology, and at the same time can provide protection for the metal surface; the chelating agent can clean the surface of the pattern and reduce the burrs at the pattern edge while increasing the development rate. By using the above-mentioned multifunctional components, the present invention achieves the effect of reducing the types and amounts of formula raw material components, and realizes the purpose of simplifying the production process and reducing costs; the present invention obtains the development and metal protection effects through the compounding of multiple components; without using strong alkali, the reagent properties are relatively mild, which provides more guarantee for the safety of operators; the formula components are all selected from biodegradable raw materials, phosphorus-free, and the preparation process is simple and convenient.

[0035] The above detailed description of an environmentally friendly developer with metal protection ability with reference to the embodiments is illustrative rather than restrictive. Several embodiments can be listed according to the defined scope. Therefore, changes and modifications within the general concept of the present invention should fall within the protection scope of the present invention.

Claims

1. An environmentally friendly developer with metal protection capability, characterized in that: The developer comprises the following components by weight percentage of raw materials: Organic amine 4-8%, Environmentally friendly solvent 6-20%, Chelating agent 1-4%, Surfactant 0.5-2%, Polylysine 0.1-0.5%, The balance is water.

2. The environmentally friendly developer with metal protection capability according to claim 1, characterized in that: The organic amine is at least one of monoethanolamine, diethanolamine, triethanolamine, diglycolamine, isopropanolamine, diisopropanolamine and 2-amino-2-methyl-1-propanol.

3. The environmentally friendly developer with metal protection capability according to claim 1, characterized in that: The environmentally friendly solvent is at least one of γ-valerolactone, dimethyl isosorbide, and triacetin.

4. The environmentally friendly developer with metal protection capability according to claim 1, characterized in that: The chelating agent is at least one of sodium citrate, sodium potassium tartrate, sodium malate, sodium gluconate, and trisodium methylglycine diacetate.

5. The environmentally friendly developer with metal protection capability according to claim 1, characterized in that: The surfactant is rhamnolipid, or a compound of rhamnolipid and other surfactants.

6. The environmentally friendly developer with metal protection capability according to claim 5, characterized in that: The rhamnolipid is at least one of monorhamnolipid and disrhamnolipid.

7. The environmentally friendly developer with metal protection capability according to claim 5, characterized in that: The other surfactants compounded with rhamnolipid are degradable active agents, including but not limited to alkyl glycosides, sucrose fatty acid esters, polyoxyethylene ether sulfates, etc.

8. The environmentally friendly developer with metal protection capability according to claim 1, characterized in that: The polymerization degree of the polylysine is 25-30.

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