A metal ion cleaning agent for semiconductor materials

Abstract

The invention relates to the technical field of semiconductor cleaning, and comprises the following components in parts by weight: 10%-16% surfactant; 0.1%-0.2% triethanolamine; 2%-5% sodium benzoate; 4%-8% phosphate; 3%-6% sodium silicate; 0.5%-1% sodium hydroxide; 0.3%-0.5% oleic acid; 0.5%-0.8% oleyl alcohol; 0.6%-1% ethanol; and the balance is water. The invention discloses a metal ion cleaning agent for semiconductor materials. The cleaning agent forms a mixed homogeneous system, so that the cleaning agent has strong decontamination and degreasing capabilities. Through the synergistic effect and complementary effect of multiple substances in the cleaning agent, the surface of the cleaned parts is smooth, the permeability cavity is strong, the wettability is good, the process cycle is short, the amount of chemical reagents is small, the cleaning solution concentration is low, it is easy to rinse, and the environmental protection is high.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor cleaning, in particular to a metal ion cleaning agent for semiconductor materials. Background Art

[0002] Chemical cleaning refers to the process of using various chemical reagents and organic solvents to react chemically or dissolve impurities and oil stains adsorbed on the surface of the object to be cleaned, or accompanied by physical measures such as ultrasound, heating, and vacuuming, so that impurities are desorbed (desorbed) from the surface of the object to be cleaned, and then rinsed with a large amount of high-purity hot or cold deionized water to obtain a clean surface.

[0003] The RCA cleaning process is called the industrial standard wet cleaning process. In production, the RCA method and the improvement based on the RCA cleaning method are commonly used for cleaning the surface of semiconductor materials. The RCA cleaning method mainly consists of a series of orderly intrusions of different chemical liquids, namely, cleaning agent I (APM) and cleaning agent II (HPM). The configuration of cleaning agent I (APM) is deionized water, 30% hydrogen peroxide, and 25% ammonia water in a volume ratio of 5:1:1 to 5:2:1; the configuration of cleaning agent II (HPM) is deionized water, 30% hydrogen peroxide, and 25% hydrochloric acid in a volume ratio of 6:1:1 to 8:2:1. The cleaning principle is: ammonia molecules, chloride ions, etc. form stable complexes with heavy metal ions such as copper ions and iron ions, such as: [AuCl4] - , [Cu(NH3)4] 2+ 、[SiF6] 2- .

[0004] When cleaning, it should generally be cleaned at 75-85℃ for about 15 minutes, and then rinsed with deionized water. Since RCA cleaning uses a large amount of chemical liquid, it poses a great threat to human health and safety. In addition, the use of a large amount of chemical liquid increases factory costs and pollutes the environment. In addition, the future development direction of cleaning technology is to reduce chemical liquids and cleaning processes.

[0005] Therefore, there is an urgent need for a cleaning process method and related cleaning agent that has fewer cleaning steps, uses a small amount of chemical reagents, has a low cleaning solution concentration, and is environmentally friendly. Summary of the invention

[0006] The object of the present invention is to provide a metal ion cleaning agent for semiconductor materials to solve the problems of large usage, high concentration and environmental pollution of the existing cleaning agents mentioned in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solution: a metal ion cleaning agent for semiconductor materials, comprising the following components in weight percentage:

[0008] Surfactant 10%-16%; triethanolamine 0.1%-0.2%; sodium benzoate 2%-5%; phosphate 4%-8%; sodium silicate 3%-6%; sodium hydroxide 0.5%-1%; oleic acid 0.3%-0.5%; oleyl alcohol 0.5%-0.8%; ethanol 0.6%-1%; the balance is water.

[0009] As a further illustration of the present invention, the following components in weight percentage are included:

[0010] Surfactant 10%; triethanolamine 0.1%; sodium benzoate 2%; phosphate 4%; sodium silicate 3%; sodium hydroxide 0.5%; oleic acid 0.3%; oleyl alcohol 0.5%; ethanol 0.6%; the balance is water.

[0011] As a further illustration of the present invention, the following components in weight percentage are included:

[0012] Surfactant 16%; triethanolamine 0.2%; sodium benzoate 5%; phosphate 8%; sodium silicate 6%; sodium hydroxide 1%; oleic acid 0.5%; oleyl alcohol 0.8%; ethanol 1%; the balance is water.

[0013] As a further illustration of the present invention, the surfactant includes: sodium alkylbenzene sulfonate, polyoxyethylene fatty alcohol ether, polyoxyethylene octylphenol ether, dodecyl diethanolamide, triethanolamine oleate soap and dodecyl phosphate diethanolamine salt.

[0014] As a further illustration of the present invention, the phosphate includes sodium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate and trisodium phosphate.

[0015] As a further illustration of the present invention, the weight ratio of the sodium alkylbenzene sulfonate, polyoxyethylene fatty alcohol ether, polyoxyethylene octylphenol ether, dodecyl diethanolamide, triethanolamine oleic acid soap and dodecyl phosphate diethanolamine salt is: 1:2:2:2:1:1.

[0016] As a further illustration of the present invention, the weight ratio of the sodium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate and trisodium phosphate is: 1:3:1:1.

[0017] The method for using the metal ion cleaning agent is specifically as follows: the semiconductor material is immersed in the cleaning agent and vibrated for cleaning for 10-15 minutes, and then rinsed with deionized water; the immersion cleaning temperature is controlled at 10-60 degrees Celsius, and the immersion vibration cleaning equipment is a megasonic cleaning equipment.

[0018] The semiconductor material is silicon material or ceramic material.

[0019] The invention discloses an application of a metal ion cleaning agent for semiconductor materials in cleaning of semiconductor materials.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention realizes that the metal ion cleaning agent of the semiconductor material forms a mixed homogeneous system by setting the surfactant, phosphate and deionized water, so that the cleaning agent has strong decontamination and degreasing ability. Through the synergistic effect and complementary effect of multiple substances in the cleaning agent, the surface of the cleaned parts is smooth, the penetration cavity is strong, and the wettability is good. Some parts with complex geometric shapes can also be cleaned, and the residual cleaning agent itself can be easily washed away. The toxicity is low, and all components in the cleaning agent are degradable in the organism and will not cause cumulative toxicity. There is only a small amount of volatile matter in ethanol, and the volatile matter is small, so there is no gas inhalation hazard. A small amount of auxiliary agent is low in toxicity and slightly toxic, and acute and malignant poisoning will not occur. It is easy to use, and the material can be cleaned by direct immersion and vibration cleaning. The cleaning of complex geometric shapes can be cleaned very well in 15-20 minutes, so that the entire process cycle is short, the amount of chemical reagents is small, the cleaning solution concentration is low, and it is easy to rinse, and the environmental protection is high. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0023] Embodiment 1: The present invention provides a technical solution: a metal ion cleaning agent for semiconductor materials, comprising the following components in weight percentage:

[0024] Surfactant 10%-16%; triethanolamine 0.1%-0.2%; sodium benzoate 2%-5%; phosphate 4%-8%; sodium silicate 3%-6%; sodium hydroxide 0.5%-1%; oleic acid 0.3%-0.5%; oleyl alcohol 0.5%-0.8%; ethanol 0.6%-1%; the balance is water.

[0025] The present invention is a cleaning agent with surfactant as the main body, and its cleaning function is mainly related to the chemical properties of the surfactant. The molecular structure of the surfactant has two parts: a hydrophilic group and a lipophilic group. In the water, air, and oil system, it tends to accumulate on the surface or interface. The molecules are arranged in a directional manner, the hydrophilic group extends into the water phase, and the lipophilic group extends into the air or oil phase, so that the surface or interfacial tension is reduced. Combined with the effects of penetration, solubilization, and emulsification, it can dissolve oil stains from the surface of parts and play a role in cleaning and washing. The rest are auxiliary agents, whose functions are to improve and enhance the chemical activity of the surfactant, buffer the pH value, inhibit the appearance of harmful particles, enhance the function of the cleaning agent, etc.

[0026] Specifically, triethanolamine can inhibit the hydrolysis of triethanolamine oleic acid soap, and it is also a surfactant. Sodium benzoate is a good penetrant and solubilizer, which facilitates the mutual dissolution and complementarity of various substances in the cleaning agent.

[0027] Specifically, sodium silicate, also known as water glass, is a cheap alkali that generates OH when hydrolyzed in water. -1， Provide alkalinity. Therefore, sodium carbonate has a buffering effect, preventing certain non-ferrous metals from corroding like strong alkali. It can form stable colloids in water and form solvated micelles. When used with surfactants, it has a good detergent effect. Silicates will hydrolyze in water. The silicic acid generated by hydrolysis is insoluble in water, but is suspended in the tank liquid in a micellar structure. This solvated micelle has the ability to suspend and disperse solid dirt particles and emulsify oil dirt, which is beneficial to prevent dirt from re-depositing on the surface of the workpiece. Silicates have a buffering effect, that is, when acidic dirt exists, its pH value remains almost unchanged.

[0028] Sodium silicate can also form precipitation with high-valent metal ions in water to form insoluble calcium carbonate, so it has a certain softening ability for hard water. It can remove iron salts in water and can also complex calcium and magnesium ions to soften water.

[0029] Specifically, sodium hydroxide dissolves in water and ionizes to produce OH -1 , providing alkalinity, and can react with oil to saponify during cleaning, generating water-soluble glycerol and fatty acid salts, which are dissolved and dispersed in the aqueous solution. The generated fatty acid sodium soap is not only water-soluble itself, but also acts as a surfactant, which can emulsify and disperse the inactive oil stains by the residual alkali. The same phenomenon can also occur when there are carboxylic acid groups and sulfonic acid groups in the oil. In addition, a small amount of sodium hydroxide can adjust the pH value of the entire cleaning agent, making the pH value of the cleaning agent weakly alkaline.

[0030] Specifically, oleic acid and sodium salt in the components form sodium oleate, which has good detergency and can be used as a surfactant such as an emulsifier.

[0031] Specifically, the surface tension of detergents containing surfactants such as oleyl alcohol and ethanol is very low, and the interfacial energy is small. Therefore, when air is mixed into the solution, the surfactant molecules are arranged in a certain order and adsorbed on the gas-liquid interface, so that the bubbles formed have a certain viscosity and tend to be stable. A large number of bubbles are separated by only a thin layer of liquid film and a large number of bubbles gather to form foam. The right amount of foam helps to suspend oil pollution. However, if there is too much foam, it will emerge from the cleaning machine, not only polluting the site, but also causing the loss of cleaning agent. Oleyl alcohol and ethanol have a very effective defoaming effect. By using ethanol as a solubilizer for oleyl alcohol, when the bubble film spreads on the liquid surface, it will take away the liquid in the adjacent surface layer, making the liquid film locally thinner, so that the liquid film ruptures to achieve the purpose of defoaming.

[0032] Specifically, the surfactant includes sodium alkylbenzene sulfonate, polyoxyethylene fatty alcohol ether, polyoxyethylene octylphenol ether, dodecyl diethanolamide, triethanolamine oleic acid soap and dodecyl phosphate diethanolamine salt. The weight ratio of sodium alkylbenzene sulfonate, polyoxyethylene fatty alcohol ether, polyoxyethylene octylphenol ether, dodecyl diethanolamide, triethanolamine oleic acid soap and dodecyl phosphate diethanolamine salt is 1:2:2:2:2:1.

[0033] Sodium alkylbenzene sulfonate has the functions of cleaning, wetting, foaming, emulsifying and dispersing surfactants; polyoxyethylene fatty alcohol ether: light yellow viscous liquid is easily soluble in oil and other organic solvents, and is used as a lipophilic penetrating emulsifier; polyoxyethylene octylphenol ether is used as a dispersant; dodecyl diethanolamide has good water solubility, and is used as an emulsifier, and has an anti-rust effect, and plays a role in stabilizing foam and cleaning in cleaning agents; triethanolamine oleic acid soap and dodecyl phosphate diethanolamine salt are used to remove metal ions attached to the surface of semiconductor material products.

[0034] Specifically, the phosphate includes sodium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate and trisodium phosphate. The weight ratio of sodium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate and trisodium phosphate is 1:3:1:1.

[0035] Trisodium phosphate generates phosphoric acid with a very low degree of dissociation during hydrolysis, thereby obtaining alkalinity. Therefore, it is a good acid-base buffer, which stabilizes the pH value of the cleaning agent at around 9. Trisodium phosphate has the effect of softening hard water and a more obvious effect of promoting the dispersion (emulsification) of dirt particles. It also has a high alkalinity and can dissolve fatty dirt through saponification. Other phosphates, including sodium pyrophosphate, sodium tripolyphosphate, and sodium hexametaphosphate, all have an important property, that is, when used as multivalent integrators, the formed integrators will not precipitate from the aqueous solution, that is, the softening effect of phosphates on water will not produce any precipitation. Sodium hexametaphosphate has the strongest chelating force for calcium ions, sodium pyrophosphate has the strongest chelating force for magnesium ions, and sodium tripolyphosphate has an integration force for calcium and magnesium ions between the two. All phosphates, especially sodium tripolyphosphate, have a significant synergistic effect with sodium dodecylbenzene sulfonate, and the composite ratio of the two greatly improves the cleaning effect compared to using only one of them. In addition, they also have buffering, dispersing, and promoting emulsification.

[0036] In addition, sodium pyrophosphate has a certain phosphating effect on metal parts at 50-60 degrees Celsius, which improves the corrosion resistance of metal materials. The appropriate ratio and concentration will not cause corrosion to the product itself, increase the roughness of the product, and affect the product quality.

[0037] Embodiment 2: A metal ion cleaning agent for semiconductor materials, comprising the following components in weight percentage:

[0038] Surfactant 10%; triethanolamine 0.1%; sodium benzoate 2%; phosphate 4%; sodium silicate 3%; sodium hydroxide 0.5%; oleic acid 0.3%; oleyl alcohol 0.5%; ethanol 0.6%; the balance is water.

[0039] Embodiment 3: A metal ion cleaning agent for semiconductor materials, comprising the following components in weight percentage: comprising the following components in weight percentage:

[0040] Surfactant 16%; triethanolamine 0.2%; sodium benzoate 5%; phosphate 8%; sodium silicate 6%; sodium hydroxide 1%; oleic acid 0.5%; oleyl alcohol 0.8%; ethanol 1%; the balance is water.

[0041] Embodiment 4: The specific method of using the metal ion cleaning agent is as follows: the semiconductor material is immersed in the cleaning agent and vibrated for cleaning for 10-15 minutes, and then rinsed with deionized water; the immersion cleaning temperature is controlled at 10-60 degrees Celsius, and the immersion vibration cleaning equipment is a megasonic cleaning equipment.

[0042] The configuration concentration (unit: %, weight percentage) of the cleaning solution in the specific method is shown in Table 1:

[0043] The comparative example is an alkaline degreasing solution in a cleaning agent for degreasing the surface of a semiconductor material, publication number: CN113980747A: 2.6% potassium hydroxide, 2.6% potassium carbonate, 3.5% dipotassium dihydrogen pyrophosphate, 2.6% potassium tripolyphosphate, 5.5% glycerol acetone acetal, 1.4% sodium dodecyl diphenyl ether disulfonate, 1.8% H-66, 1.7% fatty amine polyoxyethylene ether, and the balance is deionized water.

[0044] Table 1:

[0045]

[0046]

[0047] According to the steps in the comparative example, an alkaline degreasing solution was prepared. Degreasing test was performed by experiment:

[0048] Experimental part:

[0049] Preparation of artificial oil pollution (weight percentage)

[0050] Refer to JB / T4323.2-1999 water-based metal cleaning agent test method.

[0051] 2 parts of N32HL hydraulic oil (general-purpose machine tool industrial oil);

[0052] 1 part of industrial white vaseline;

[0053] 1 part of barium petroleum sulfonate;

[0054] Mix the above components, dissolve at about 120 degrees Celsius and stir evenly.

[0055] The test piece material is 45# steel as the test piece for oil removal rate test. The test piece diameter is 50mm, the thickness is 3-5mm, and the surface roughness is Ra0.16-0.63.

[0056] Use tweezers to pick up absorbent cotton and clean the polished test piece in anhydrous ethanol and acetone in turn, blow dry with hot air, and place in a dryer to cool for later use. For rust and corrosion test pieces, the standby time should not exceed 16 hours from the time the test piece is polished, otherwise it should be reprocessed.

[0057] Determination of fat removal rate

[0058] Refer to JB / T4323.2-1999 water-based metal cleaning agent test method.

[0059] Soak the oiled test piece in the cleaning solution (25°C) for 3 min, then wash it in a swaying position for 30 min, rinse it with water for 5 s and air dry it.

[0060] Put it in a dryer and keep it constant weight for 20 minutes, weigh W2, and its degreasing rate is:

[0061] Degreasing rate = (W1-W2) / (W1-W0)×100%

[0062] Where W0 is the weight of the unoiled specimen (g),

[0063] W1 is the weight of the test piece after oil coating (g),

[0064] W2 is the weight of the clean test piece with all oil removed (g).

[0065] The degreasing rate is shown in Table 2:

[0066] Table 2

[0067] Degreasing rate (%) Comparative Example 88.18 Embodiment 2 95.53 Embodiment 3 98.03

[0068] As can be seen from Table 2.2, the degreasing rate of the comparative example is low, while the degreasing rate of the cleaning agent of the present invention is relatively high, and both Examples 2 and 3 exceed 95%. However, since different cleaning agents have different cloud points, the properties will change beyond the cloud point, thus affecting the degreasing performance. Because the temperature of degreasing cleaning sometimes needs to be heated, the cleaning agent of the present invention performs best when used at a temperature of 20-50 degrees Celsius.

[0069] In addition, when the cleaning agent removes metal ions, the amount of metal ions chelated by phosphate is shown in Table 3:

[0070] Table 3

[0071]

[0072] Since calcium and magnesium ions in water can reduce the degreasing rate of surfactants, adding phosphates can play a role in dispersion, coordination, and preventing oil from settling, and can adjust the pH value of the solution to improve the degreasing performance of surfactants. If sodium carbonate is added, precipitation will occur, so phosphates such as sodium tripolyphosphate are selected as pH regulators to improve cleaning and dispersion performance.

[0073] Embodiment 5: The semiconductor material is a silicon material or a ceramic material. A metal ion cleaning agent for semiconductor materials is used in cleaning semiconductor materials.

[0074] The present invention realizes that the metal ion cleaning agent of the semiconductor material forms a mixed homogeneous system by setting the surfactant, phosphate and deionized water, so that the cleaning agent has strong decontamination and degreasing ability. Through the synergistic effect and complementary effect of multiple substances in the cleaning agent, the surface of the cleaned parts is smooth, the penetration cavity is strong, and the wettability is good. Some parts with complex geometric shapes can also be cleaned, and the residual cleaning agent itself can be easily washed away. The toxicity is low, and all components in the cleaning agent are degradable in the organism and will not cause cumulative toxicity. There is only a small amount of volatile matter in ethanol, and the volatile matter is small, so there is no gas inhalation hazard. A small amount of auxiliary agent is low in toxicity and slightly toxic, and acute and malignant poisoning will not occur. It is easy to use, and the material can be cleaned by direct immersion and vibration cleaning. The cleaning of complex geometric shapes can be cleaned very well in 15-20 minutes, so that the entire process cycle is short, the amount of chemical reagents is small, the cleaning solution concentration is low, and it is easy to rinse, and the environmental protection is high.

[0075] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

Claims

1. A metal ion cleaning agent for semiconductor materials, characterized in that: The composition includes the following weight percentages: Surfactant 10%-16%; triethanolamine 0.1%-0.2%; sodium benzoate 2%-5%; phosphate 4%-8%; sodium silicate 3%-6%; sodium hydroxide 0.5%-1%; oleic acid 0.3%-0.5%; Oleyl alcohol 0.5%-0.8%; ethanol 0.6%-1%; the balance is water; The surfactant includes: sodium alkylbenzene sulfonate, polyoxyethylene fatty alcohol ether, polyoxyethylene octylphenol ether, dodecyl diethanolamide, triethanolamine oleic acid soap and dodecyl phosphate diethanolamine salt; The phosphates include sodium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate and trisodium phosphate; The weight ratio of the sodium alkylbenzene sulfonate, polyoxyethylene fatty alcohol ether, polyoxyethylene octylphenol ether, dodecyl diethanolamide, triethanolamine oleic acid soap and dodecyl phosphate diethanolamine salt is: 1:2:2:2:1:1; The weight ratio of the sodium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate and trisodium phosphate is 1:3:1:

1.

2. The metal ion cleaning agent for semiconductor materials according to claim 1, characterized in that: The composition includes the following weight percentages: Surfactant 10%; triethanolamine 0.1%; sodium benzoate 2%; phosphate 4%; sodium silicate 3%; sodium hydroxide 0.5%; oleic acid 0.3%; oleyl alcohol 0.5%; ethanol 0.6%; the balance is water.

3. The metal ion cleaning agent for semiconductor materials according to claim 1, characterized in that: The composition includes the following weight percentages: Surfactant 16%; triethanolamine 0.2%; sodium benzoate 5%; phosphate 8%; sodium silicate 6%; sodium hydroxide 1%; oleic acid 0.5%; oleyl alcohol 0.8%; ethanol 1%; the balance is water.

4. The metal ion cleaning agent for semiconductor materials according to claim 1, characterized in that: The semiconductor material is silicon material or ceramic material.

5. Use of the metal ion cleaning agent for semiconductor materials according to any one of claims 1 to 4 in cleaning semiconductor materials.

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