Alkali etching reagent for low surface roughness of monocrystalline silicon ring and cleaning method
Through the combination of acid liquid, cleaning liquid and alkali liquid, the roughness of the surface of the single crystal silicon ring is gradually reduced, the acid polishing corrosion problem is solved, and the wafer drying effect and the integrity of the gas channel are ensured.
Patent Information
- Application Number
- CN202411332176.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-24
- Publication Date
- 2024-12-31
AI Technical Summary
In the existing semiconductor wafer dry engraving process, acidic polishing liquid will corrode the gas channels on the single crystal silicon ring, resulting in an increase in surface roughness and affecting the dry engraving effect.
Provide an alkali reagent system including acid liquid, cleaning liquid and alkali liquid. Through the steps of acid cleaning, pure water overflow cleaning, cleaning liquid pre-cleaning and alkaline polishing, the roughness of the surface of the single crystal silicon ring is gradually reduced. The gas channel form is retained and not destroyed.
It effectively reduces the roughness of the surface of the single crystal silicon ring, ensures that the gas can pass at a uniform speed, ensures the wafer drying effect, and avoids changes in temperature and plasma activity caused by the increase in roughness.
Smart Images
Figure CN119221119A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of semiconductors and relates to an alkali etching reagent with low roughness on the surface of a single crystal silicon ring and a cleaning method and application thereof. Background Art
[0002] In the semiconductor wafer dry etching process, there is a single crystal silicon ring with uneven and tiny gas channels evenly distributed on its surface. Through the polishing and cleaning process, in addition to removing surface contaminants, the polishing effect is achieved while keeping the gas channel shape intact.
[0003] The existing polishing technology is mainly acid polishing, which can not only remove surface pollutants but also achieve a polishing effect. However, the acid polishing liquid will also cause the fine gas channels on the surface to be polished and corroded. After cleaning, the surface concave and convex gas channels are obviously destroyed. If only alkaline corrosion cleaning is performed, the reaction speed of the concave areas is fast, which will lead to greater depth differences and increase the roughness of the product surface. When the roughness increases further, the gas flow rate is large when the wafer is dry-etched, which changes the temperature in the cavity and the plasma activity, and ultimately affects the dry-etching effect of the wafer. There is an urgent need to improve the etching preparations and etching methods for silicon products. Summary of the invention
[0004] In view of this, the object of the present invention is to provide an alkaline etching agent for reducing the surface roughness of a single crystal silicon ring, and also to provide an etching application of the agent on a silicon product.
[0005] In order to achieve the above object, the present invention provides the following technical solutions:
[0006] One of the purposes of the present invention is to provide an alkali etching reagent with low surface roughness of a single crystal silicon ring, the alkali etching reagent comprising an acid solution, a cleaning solution and an alkali solution;
[0007] The acid solution is composed of 4-8% ammonium fluoride, 25-35% sulfuric acid, 1-3% nitric acid, 0.01-0.02% non-ionic fluorocarbon surfactant and 0.1-0.3% diethylaminoethanol hexanoate by mass percentage, and the balance is water;
[0008] The cleaning solution is composed of 3-8% carbonate compound, 0.1-0.5% sodium nitrophenolate, 0.01-0.02% fluorosilicone surfactant, 0.01-0.03% polyoxyethylene polyoxypropylene pentaerythritol ether, and the balance is water, in terms of mass percentage;
[0009] The alkali solution is composed of 2-8% hydroxide, 0.3-0.7% accelerator, 0.1-0.5% hydroquinone, 0.002-0.02% sodium dimethyl-dithiocarboxamide sulfonate, 0.02-0.1% polyether modified heptamethyl trisiloxane, 0.01-0.2% sodium fatty alcohol polyoxyethylene ether sulfate, and the balance is water.
[0010] Furthermore, the nonionic fluorocarbon surfactant is selected from one of Capstone FS-30, FC-4430 and FCF-206.
[0011] Furthermore, the fluorosilicone surfactant is selected from one of BNK-4046, BNK-4036, and FS-3100.
[0012] Furthermore, the carbonate compound is selected from one of potassium carbonate, sodium carbonate, calcium carbonate, magnesium carbonate, sodium bicarbonate and calcium bicarbonate.
[0013] Preferably, the carbonate compound is selected from potassium carbonate or sodium carbonate.
[0014] Furthermore, the accelerator is selected from one of ammonium persulfate, sodium nitrite, pullulan and the like.
[0015] Furthermore, the hydroxide compound is selected from potassium hydroxide or sodium hydroxide.
[0016] Preferably, the acid solution is composed of 4-6% ammonium fluoride, 25-30% sulfuric acid, 1-3% nitric acid, 0.01-0.02% nonionic fluorocarbon surfactant and 0.1-0.3% diethylaminoethanol hexanoate by mass percentage, and the balance is water. In this concentration range, the surface roughness of the sample is lower.
[0017] Preferably, the cleaning solution is composed of 3-7% carbonate compound, 0.1-0.4% sodium nitrophenolate, 0.01-0.02% fluorosilicone surfactant, 0.01-0.03% polyoxyethylene polyoxypropylene pentaerythritol ether, and the balance is water, in terms of mass percentage.
[0018] Preferably, the alkali solution is composed of 2-6% hydroxide, 0.3-0.7% accelerator, 0.1-0.5% hydroquinone, 0.002-0.02% sodium dimethyl-dithiocarboxamide sulfonate, 0.02-0.1% polyether-modified heptamethyl trisiloxane, 0.01-0.2% sodium fatty alcohol polyoxyethylene ether sulfate, and the balance is water.
[0019] The second object of the present invention is to use the above-mentioned alkaline etching reagent to reduce the surface alkali etching roughness of the single crystal silicon ring. The specific steps are to sequentially perform acid cleaning and polishing, pure water overflow cleaning, cleaning liquid pre-cleaning and alkaline cleaning and polishing on the silicon product.
[0020] In a further cleaning method, the acid cleaning and polishing is specifically to immerse the sample in an acid solution at a temperature of 25-35° C. and rotate and clean it for 3-10 minutes. More specifically, the silicon sample is placed on a tooling and rotated automatically.
[0021] In the further cleaning method, the cleaning solution pre-cleaning is specifically to immerse the silicon sample in the cleaning solution at a temperature of 40° C.-50° C. for 5-10 minutes.
[0022] In a further cleaning method, alkaline cleaning and polishing is specifically performed by immersing the sample in an alkaline solution at a temperature of 50° C. to 60° C. and rotating and cleaning the sample for 10 to 30 minutes. More specifically, the silicon sample is placed on a tooling and rotated automatically.
[0023] In a further cleaning method, during the pure water overflow cleaning, the acid-washed silicon ring sample is immersed in pure water for overflow cleaning;
[0024] Preferably, the device is immersed in pure water for overflow cleaning for 5-10 minutes.
[0025] The third object of the present invention is to provide the use of any of the above-mentioned alkaline etching reagents in etching silicon products, which can reduce the surface roughness of the silicon products after etching.
[0026] The beneficial effects of the present invention are as follows: the present invention provides an alkaline etching reagent for reducing the surface roughness of a single crystal silicon ring, specifically comprising an acid solution, a cleaning solution and an alkaline solution used in alkaline etching cleaning, and the silicon ring product is first cleaned and polished using different reagent systems of the alkaline etching reagent in sequence. The initial acid cleaning is an isotropic reaction to single crystal silicon, which can make the depth of the gas channel on the silicon ring tend to be consistent. Then, the cleaning solution prepared by the present invention is used for pre-cleaning, which not only removes the acidic substances remaining in the acid cleaning step, but also stimulates the reaction between silicon and alkali in the next step, laying the foundation for further alkaline solution cleaning and polishing. The purpose of the alkaline solution cleaning is to achieve a polishing effect on the surface of the silicon ring product through this process, while retaining the gas channel morphology from being destroyed, reducing the surface roughness of the product, so as to ensure that the plasma gas can pass through the gas flow channel on the product at a uniform speed during the semiconductor wafer dry etching process of the silicon ring product, thereby ensuring the wafer dry etching effect. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:
[0028] Figure 1 This is a real photo of the silicon ring sample of Example 1.
[0029] Figure 2 This is a 400x high-definition digital microscope image of the large flat surface of the groove of the silicon ring sample of Example 1.
[0030] Figure 3 This is a real photo of the silicon ring sample of Example 2.
[0031] Figure 4 This is a 400x high-definition digital microscope image of the step on the surface of the silicon ring sample of Example 2.
[0032] Figure 5 This is a 400x high-definition digital microscope image of the large flat surface of the groove of the silicon ring sample in Example 3.
[0033] Figure 6 This is a real photo of the silicon ring sample of Example 4.
[0034] Figure 7 This is a 300x high-definition digital microscope image of the groove at the edge of the silicon ring sample in Example 4.
[0035] Figure 8 This is a 400x high-definition digital microscope image of the large flat surface of the groove of the silicon ring sample in Example 5.
[0036] Fig. 9 This is a real photo of the silicon ring sample of Comparative Example 1.
[0037] Fig.10 This is a 400x high-definition digital microscope image of the surface of the silicon ring sample of Comparative Example 1 after cleaning and polishing.
[0038] Fig.11 This is a 400-fold high-definition digital microscope image of the surface of the silicon ring sample of Comparative Example 2.
[0039] Fig.12 This is a 400-fold high-definition digital microscope image of the surface of the silicon ring sample of Comparative Example 3. DETAILED DESCRIPTION
[0040] The preferred embodiment of the present invention will be described clearly and completely below in conjunction with the accompanying 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 of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. The experimental methods for which specific conditions are not specified in the embodiments are usually carried out under conventional conditions or under conditions recommended by the manufacturer.
[0041] All % used herein are mass percentages.
[0042] The invention provides an alkaline etching reagent for low-roughness surface of a single-crystal silicon ring, which specifically comprises an acid solution, a cleaning solution and an alkaline solution, and is prepared as follows: the acid solution and the cleaning solution are used for cleaning before alkaline solution polishing.
[0043] Acid solution: by mass percentage, composed of 4-8% ammonium fluoride, 25-35% sulfuric acid, 1-3% nitric acid, 0.01-0.02% nonionic fluorocarbon surfactant and 0.1-0.3% diethylaminoethanol hexanoate, and the balance is water;
[0044] The nonionic fluorocarbon surfactant is selected from any one of FS-30 (Capstone, Chemours, USA), FC-4430 (3M), and FCF-206 (Cramer).
[0045] Cleaning liquid: by mass percentage, it is composed of 3-8% carbonate compound, 0.1-0.5% sodium nitrophenolate, 0.01-0.02% fluorosilicone surfactant, 0.01-0.03% polyoxyethylene polyoxypropylene pentaerythritol ether, and the balance is water;
[0046] The carbonate compound is selected from one of potassium carbonate, sodium carbonate, calcium carbonate, magnesium carbonate, sodium bicarbonate and calcium bicarbonate.
[0047] The fluorosilicone surfactant can be selected from any one of BNK-4046 (Milliken), BNK-4036 (Milliken), and FS-3100 (Capstone, DuPont, Chemours, USA).
[0048] Alkali solution: by mass percentage, it is composed of 2-8% potassium hydroxide (or sodium hydroxide), 0.3-0.7% accelerator, 0.1-0.5% hydroquinone, 0.002-0.02% sodium dimethyl-dithiocarboxamide sulfonate, 0.02-0.1% polyether modified heptamethyl trisiloxane, 0.01-0.2% sodium fatty alcohol polyoxyethylene ether sulfate, and the balance is water;
[0049] The accelerator is selected from one of ammonium persulfate, sodium nitrite, pullulan and the like.
[0050] The sample silicon ring is a single crystal silicon ring with a diameter of 300 mm, P-type silicon.
[0051] Sodium nitrophenolate can be directly used as a commercially available finished product, or sodium 5-nitroguaiacol, sodium o-nitrophenolate and sodium p-nitrobenzene can be prepared in a mass ratio of 1:2:3.
[0052] Example 1
[0053] The alkaline etching reagent for low roughness of the surface of the single crystal silicon ring includes acid solution, cleaning solution and alkaline solution, which are respectively prepared according to the following dosages. Other conventional additives in the art can also be added without affecting the roughness.
[0054] Acid solution: by mass percentage, composed of 5% sodium fluoride, 30% sulfuric acid, 2% nitric acid, 0.01% FC-4430 and 0.2% diethylaminoethanol hexanoate, and the balance is water;
[0055] Cleaning solution: by mass percentage, composed of 5% potassium carbonate, 0.3% sodium nitrophenolate, 0.01% BNK-4046, 0.01% polyoxyethylene polyoxypropylene pentaerythritol ether, and the balance is water;
[0056] Alkali solution: by mass percentage, it is composed of 5% potassium hydroxide, 0.5% ammonium persulfate, 0.2% hydroquinone, 0.01% sodium dimethyl-dithiocarboxamide sulfonate, 0.05% polyether-modified heptamethyl trisiloxane, 0.1% sodium fatty alcohol polyoxyethylene ether sulfate, and the balance is water.
[0057] Silicon ring cleaning and polishing process:
[0058] 1. First, perform acid cleaning and preliminary micro-etching on the silicon ring sample: at a temperature of 25-35°C, turn on the circulation, place the silicon ring sample on the tooling and rotate it automatically, and immerse it in the acid solution for 3-5 minutes. The circulation is a solution circulation, which is used to make the solution in the tank flow under the action of the circulation pump. The tooling includes a motor driving the gear to rotate, which in turn drives the rotating rod connected to the gear to rotate. The silicon ring sample is placed on the rotating rod, and the silicon ring sample can rotate in a plane with a speed of 20-30rpm / min.
[0059] 2. Pure water overflow cleaning: soak the pickled silicon ring sample in pure water overflow cleaning for 5-10 minutes, preferably 5 minutes.
[0060] 3. Pre-cleaning with cleaning solution: Soak the silicon ring sample after overflow cleaning with pure water in the cleaning solution at a temperature of 40°C-50°C for 5-10 minutes, preferably 5 minutes.
[0061] 4. Alkaline cleaning and polishing: At a temperature of 50°C-60°C, open the cycle, place the cleaned silicon ring sample on the tooling, rotate it automatically, and soak it in the alkaline solution for 10-30 minutes, preferably 20min-25min.
[0062] Figure 1 This is a photo of the silicon ring sample of Example 1. Figure 2 This is a 400x high-definition digital microscope image of the large flat surface of the sample groove, with an average roughness of 0.109.
[0063] Example 2
[0064] The alkaline etching reagent for low roughness of the surface of a single crystal silicon ring comprises an acid solution, a cleaning solution and an alkaline solution, which are respectively prepared according to the following dosages.
[0065] Acid solution: by mass percentage, composed of 4% ammonium fluoride, 25% sulfuric acid, 1% nitric acid, 0.01% FS-30 and 0.1% diethylaminoethanol hexanoate, and the balance is water;
[0066] Cleaning solution: by mass percentage, composed of 3% sodium carbonate, 0.1% sodium nitrophenolate, 0.01% BNK-4036, 0.01% polyoxyethylene polyoxypropylene pentaerythritol ether, and the balance is water;
[0067] Alkali solution: by mass percentage, it is composed of 2% potassium hydroxide, 0.3% sodium nitrite, 0.1% hydroquinone, 0.002% sodium dimethyl-dithiocarboxamide sulfonate, 0.02% polyether modified heptamethyl trisiloxane, 0.05% sodium fatty alcohol polyoxyethylene ether sulfate, and the balance is water.
[0068] The cleaning and polishing process of the silicon ring product is the same as that of Example 1.
[0069] Figure 3 This is a photo of the silicon ring sample of Example 2. Figure 4 This is a 400x high-definition digital microscope image of the sample surface steps, with an average roughness of 0.101.
[0070] Example 3
[0071] The alkaline etching reagent for low roughness of the surface of a single crystal silicon ring comprises an acid solution, a cleaning solution and an alkaline solution, which are respectively prepared according to the following dosages.
[0072] Acid solution: by mass percentage, composed of 8% ammonium fluoride, 35% sulfuric acid, 3% nitric acid, 0.02% FCF-206 and 0.3% diethylaminoethanol hexanoate, and the balance is water;
[0073] Cleaning solution: by mass percentage, it is composed of 8% sodium carbonate, 0.5% sodium nitrophenolate, 0.02% FS-3100, 0.03% polyoxyethylene polyoxypropylene pentaerythritol ether, and the balance is water;
[0074] Alkali solution: by mass percentage, it is composed of 8% potassium hydroxide, 0.7% pullulan, 0.5% hydroquinone, 0.02% sodium dimethyl-dithiocarboxamide sulfonate, 0.1% polyether modified heptamethyl trisiloxane, 0.2% sodium fatty alcohol polyoxyethylene ether sulfate, and the balance is water.
[0075] The cleaning and polishing process of the silicon ring product is the same as that of Example 1.
[0076] Figure 5 This is a 400x high-definition digital microscope image of the large flat surface of the groove of the silicon ring sample in Example 3, and its average roughness is 0.132.
[0077] Example 4
[0078] The alkaline etching reagent for low roughness of the surface of a single crystal silicon ring comprises an acid solution, a cleaning solution and an alkaline solution, which are respectively prepared according to the following dosages.
[0079] Acid solution: by mass percentage, composed of 6% ammonium fluoride, 28% sulfuric acid, 2% nitric acid, 0.01% FS-30 and 0.15% diethylaminoethanol hexanoate, and the balance is water;
[0080] Cleaning solution: by mass percentage, it is composed of 6% potassium carbonate, 0.4% sodium nitrophenolate, 0.01% FS-3100, 0.02% polyoxyethylene polyoxypropylene pentaerythritol ether, and the balance is water;
[0081] Alkali solution: by mass percentage, it is composed of 6% sodium hydroxide, 0.4% sodium nitrite, 0.2% hydroquinone, 0.01% sodium dimethyl-dithiocarboxamide sulfonate, 0.05% polyether modified heptamethyl trisiloxane, 0.1% sodium fatty alcohol polyoxyethylene ether sulfate, and the balance is water.
[0082] The cleaning and polishing process of the silicon ring product is the same as that of Example 1.
[0083] Figure 6 This is a photo of the silicon ring sample of Example 4. Figure 7 This is a 300x high-definition digital microscope image of the groove at the edge of the sample, with an average roughness of 0.106.
[0084] Example 5
[0085] The alkaline etching reagent for low roughness of the surface of a single crystal silicon ring comprises an acid solution, a cleaning solution and an alkaline solution, which are respectively prepared according to the following dosages.
[0086] Acid solution: by mass percentage, composed of 5% ammonium fluoride, 26% sulfuric acid, 1.5% nitric acid, 0.01% FC-4430 and 0.2% diethylaminoethanol hexanoate, and the balance is water;
[0087] Cleaning solution: by mass percentage, composed of 7% sodium carbonate, 0.3% sodium nitrophenolate, 0.02% BNK-4046, 0.01% polyoxyethylene polyoxypropylene pentaerythritol ether, and the balance is water;
[0088] Alkali solution: by mass percentage, it is composed of 4% potassium hydroxide, 0.4% pullulan, 0.2% hydroquinone, 0.01% sodium dimethyl-dithiocarboxamide sulfonate, 0.05% polyether-modified heptamethyl trisiloxane, 0.1% sodium fatty alcohol polyoxyethylene ether sulfate, and the balance is water.
[0089] The cleaning and polishing process of the silicon ring product is the same as that of Example 1.
[0090] Figure 8 This is a 400x high-definition digital microscope image of the large flat surface of the groove of the silicon ring sample in Example 5, and its average roughness is 0.112.
[0091] Comparative Example 1
[0092] The alkali solution polishing method of the single crystal silicon ring is to prepare the alkali solution according to the following dosage.
[0093] Alkali solution: by mass percentage, it is composed of 5% potassium hydroxide, 0.5% ammonium persulfate, 0.2% hydroquinone, 0.01% sodium dimethyl-dithiocarboxamide sulfonate, 0.05% polyether-modified heptamethyl trisiloxane, 0.1% sodium fatty alcohol polyoxyethylene ether sulfate, and the balance is water.
[0094] Silicon ring product cleaning and polishing process: At a temperature of 50℃-60℃, place the silicon ring sample on the tooling and rotate it automatically in the plane, and immerse it in alkali solution, which circulates for 20 minutes.
[0095] Fig. 9 This is a photo of the silicon ring sample of Comparative Example 1. Fig.10 This is a 400x high-definition digital microscope image of the surface of the silicon ring sample after cleaning and polishing. Fig.10 As shown, the roughness varies greatly, ranging from 0.1 to 0.55.
[0096] Comparative Example 2
[0097] The alkaline solution polishing method of the single crystal silicon ring is to prepare the acid solution, the cleaning solution and the alkaline solution according to the following dosages respectively.
[0098] Acid solution: by mass percentage, composed of 9% sodium fluoride, 35% sulfuric acid, 7% nitric acid, 0.03% FC-4430 and 0.8% diethylaminoethanol hexanoate, and the balance is water;
[0099] Cleaning solution: by mass percentage, composed of 6% potassium carbonate, 0.6% sodium nitrophenolate, 0.07% BNK-4046, 0.1% polyoxyethylene polyoxypropylene pentaerythritol ether, and the balance is water;
[0100] Alkali solution: by mass percentage, it is composed of 7% potassium hydroxide, 0.9% ammonium persulfate, 0.4% hydroquinone, 0.02% sodium dimethyl-dithiocarboxamide sulfonate, 0.1% polyether modified heptamethyl trisiloxane, 0.5% sodium fatty alcohol polyoxyethylene ether sulfate, and the balance is water.
[0101] The cleaning and polishing process of the silicon ring product is the same as that of Example 1.
[0102] A 400x high-definition digital microscope image of the silicon ring sample surface after cleaning Fig.11 As shown, the overall roughness is too large, between 0.2-0.4.
[0103] Comparative Example 3
[0104] Prepare by volume ratio of hydrofluoric acid: nitric acid: acetic acid = 2:5:3, place the silicon ring product on the tooling at a temperature of 20℃-25℃, rotate it automatically on the plane, and immerse it in the above acid solution for 15 minutes. Fig.12 As shown, the average roughness value is shown to be 1.59.
[0105] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.
Claims
1. An alkaline etching reagent for low roughness of the surface of a single crystal silicon ring, characterized in that: The alkaline etching reagent comprises acid solution, cleaning solution and alkaline solution; The acid solution is composed of 4-8% ammonium fluoride, 25-35% sulfuric acid, 1-3% nitric acid, 0.01-0.02% non-ionic fluorocarbon surfactant and 0.1-0.3% diethylaminoethanol hexanoate by mass percentage, and the balance is water; The cleaning solution is composed of 3-8% carbonate compound, 0.1-0.5% sodium nitrophenolate, 0.01-0.02% fluorosilicone surfactant, 0.01-0.03% polyoxyethylene polyoxypropylene pentaerythritol ether, and the balance is water, in terms of mass percentage; The alkali solution is composed of 2-8% hydroxide, 0.3-0.7% accelerator, 0.1-0.5% hydroquinone, 0.002-0.02% sodium dimethyl-dithiocarboxamide sulfonate, 0.02-0.1% polyether modified heptamethyl trisiloxane, 0.01-0.2% sodium fatty alcohol polyoxyethylene ether sulfate, and the balance is water.
2. The alkaline etching reagent according to claim 1, characterized in that The nonionic fluorocarbon surfactant is selected from one of Capstone FS-30, FC-4430 and FCF-206.
3. The alkaline etching reagent according to claim 1, characterized in that The fluorosilicone surfactant is selected from one of BNK-4046, BNK-4036 and FS-3100.
4. The alkaline etching reagent according to claim 1, characterized in that The carbonate compound is selected from one of potassium carbonate, sodium carbonate, calcium carbonate, magnesium carbonate, sodium bicarbonate and calcium bicarbonate.
5. The alkaline etching reagent according to claim 1, characterized in that The accelerator is selected from one of ammonium persulfate, sodium nitrite, pullulan and the like.
6. The alkaline etching reagent according to any one of claims 1 to 5, characterized in that The acid solution is composed of 4-6% ammonium fluoride, 25-30% sulfuric acid, 1-3% nitric acid, 0.01-0.02% non-ionic fluorocarbon surfactant and 0.1-0.3% diethylaminoethanol hexanoate by mass percentage, and the balance is water; the cleaning solution is composed of 3-7% carbonate, 0.1-0.4% sodium nitrophenolate, 0.01-0.02% fluorosilicone surfactant, 0.01-0.03% polyoxyethylene polyoxypropylene pentaerythritol ether by mass percentage, and the balance is water; the alkali solution is composed of 2-6% hydroxide, 0.3-0.7% accelerator, 0.1-0.5% hydroquinone, 0.002-0.02% dimethyl-dithiocarboxamide sodium sulfonate, 0.02-0.1% polyether modified heptamethyl trisiloxane, 0.01-0.2% fatty alcohol polyoxyethylene ether sodium sulfate, and the balance is water.
7. A method for cleaning the surface of a single crystal silicon ring using the alkaline etching reagent according to any one of claims 1 to 6, characterized in that: The steps of the cleaning method are to sequentially perform acid cleaning, pure water overflow cleaning, cleaning liquid pre-cleaning and alkaline cleaning on the silicon product.
8. The method for cleaning the surface of a single crystal silicon ring according to claim 7, characterized in that: Acid cleaning specifically involves immersing the sample in an acid solution at a temperature of 25-35° C. and rotating and cleaning for 3-10 minutes.
9. The method for cleaning the surface of a single crystal silicon ring according to claim 7, characterized in that: The cleaning solution pre-cleaning is specifically to immerse the silicon sample in the cleaning solution at a temperature of 40°C-50°C for 5-10 minutes; the alkaline cleaning is specifically to immerse the sample in the alkaline solution at a temperature of 50°C-60°C and rotate and clean it for 10-30 minutes.
10. Use of the alkaline etching reagent according to any one of claims 1 to 6 in etching silicon products.