A cleaning agent capable of removing silicon carbide post-polishing surface residues, its preparation, use and application

Abstract

This invention proposes a cleaning agent capable of removing surface residues after silicon carbide polishing, along with its preparation, usage, and application, belonging to the field of silicon carbide wafer surface cleaning technology. The cleaning agent comprises a first component, a second component, a pH adjuster, and water. The first component contains nonionic surfactants and anionic surfactants of isomeric tridecyl alcohol polyoxyethylene ether or polyoxypropylene polyoxyethylene block copolymers. The second component contains a wetting agent, a penetrant, a dispersant, and a metal trapping agent. This cleaning agent can remove polishing fluid, binders, and other contaminants from silicon carbide wafers after the chemical mechanical polishing (CMP) process, resulting in a uniformly smooth surface that perfectly meets customer production needs. The production process involves no addition of organic solvents, making the product environmentally friendly and pollution-free.

Description

Technical Field

[0001] This invention belongs to the field of silicon carbide wafer surface cleaning technology, specifically relating to a cleaning agent capable of removing surface residues after silicon carbide polishing, its preparation and use methods, and its applications. Background Technology

[0002] Third-generation semiconductors, represented by silicon carbide (SiC) and gallium nitride (GaN), have garnered significant attention due to the rise of applications such as new energy vehicles and energy storage. SiC, in particular, exhibits significant advantages in key parameters such as bandgap, breakdown voltage, thermal conductivity, and electron saturation velocity, making it highly favored in applications requiring high voltage, high temperature resistance, high frequency, and high power. While chemical mechanical polishing (CMP) of SiC wafers significantly improves surface smoothness, it inevitably produces residues of abrasives (such as diamond microparticles) and binders, as well as byproducts from the CMP process, such as metal ions and organic matter. These tiny particles and chemical substances, under the influence of mechanical forces and in complex chemical environments, may penetrate deep into the SiC substrate surface or adhere firmly by binding with surface chemical groups, forming a difficult-to-remove contamination layer.

[0003] Existing traditional technologies and processes have insufficient oxidation efficiency (<60%) for binders (organic waxes, rosin) by SPM and easily form a sulfide contamination layer on the silicon carbide surface. DHF has a solubility rate of only 15%-20% for high-hardness abrasives (such as diamond) and can lead to excessive surface corrosion. SC1 / SC2 cleaning fluids have a removal rate of less than 50% for nano-sized abrasive particles and pose a risk of particle redeposition.

[0004] Currently, most cleaning agents on the market are hydrocarbon-based or solvent-based. While their cleaning effect is improved compared to traditional methods and they are effective at removing organic components, the overall removal effect still cannot fully meet customer needs. Furthermore, excessive dosage leads to low cleaning efficiency and certain safety risks. They also generate significant odors during production, and the emission of organic solvents pollutes the environment. Summary of the Invention

[0005] This invention addresses the problems of the prior art by providing a cleaning agent for removing surface residues after silicon carbide polishing, its preparation method, and its application.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows: In a first aspect, a cleaning agent capable of removing residues from the surface of silicon carbide after polishing includes a first component, a second component, a pH adjuster, and water; the first component contains a nonionic surfactant or anionic surfactant of isotridecyl alcohol polyoxyethylene ether or polyoxypropylene polyoxyethylene block; and the second component contains a wetting agent, a penetrant, a dispersant, and a metal trapping agent. The cleaning agent, by mass parts, comprises 3-6 parts of nonionic surfactant and 4-10 parts of anionic surfactant in the first component, 1-3 parts of wetting agent, 0-6 parts of penetrant, 1-5 parts of metal trapping agent, 2-6 parts of dispersant in the second component, and the balance being water and pH adjuster; the pH adjuster is used to adjust the pH value of the cleaning agent to 10-14.

[0007] Preferably, the nonionic surfactant of the first component is one or more of isomeric tridecyl alcohol polyoxyethylene ether and polyoxypropylene polyoxyethylene ether with an EO number of 7-12. The anionic surfactant is one or more of dodecyl sulfonic acid, dodecylbenzene sulfonic acid, and their salts.

[0008] Preferably, the wetting agent of the second component is an alkyl glycoside or mixture thereof, including one or more of APG-0810, dodecyl glucoside, lauryl glucoside APG-1214, and lauryl glucoside APG-0814 glycoside. The second component's penetrant is a alkyl alcohol polyoxyethylene ether with 4-8 EOs and a chemical structure of C6-C10, such as JFC-2. The metal scavenging agent in the second component is one or more of EDTA, aminotriacetic acid, tartaric acid, citric acid, diethylenetriaminepentaacetic acid, hydroxyethylidene diphosphonic acid, and their salts. The dispersant for the second component is one or more of sodium pyrophosphate and potassium pyrophosphate.

[0009] Preferably, the pH adjuster is one or more of sodium carbonate, sodium bicarbonate, sodium hydroxide, and potassium hydroxide.

[0010] Secondly, a method for preparing a cleaning agent capable of removing surface residues after silicon carbide polishing is described below: Add two-thirds of the required amount of pure water to a reaction vessel, add the first component while stirring, heat to 40-50°C to fully dissolve and disperse, add the second component, stir to dissolve, mix evenly, add a pH adjuster, and replenish the water to control the final pH value of the system within the range of 10-14, thus obtaining the cleaning agent.

[0011] Thirdly, the application of a cleaning agent capable of removing surface residues after silicon carbide polishing in the cleaning of silicon carbide.

[0012] Preferably, the cleaning agent is used at a temperature of 30-70°C when cleaning silicon carbide, and the cleaning time is 10-30 minutes.

[0013] Preferably, silicon carbide is cleaned by immersion in cleaning agent, ultrasonic oscillation, or spraying and rinsing with cleaning reagent.

[0014] Compared with the prior art, the advantages and positive effects of the present invention are as follows: This application discloses a cleaning agent capable of removing surface residues from polished silicon carbide. It effectively removes polishing slurry, binders, and especially high-hardness abrasives from the polishing slurry and stubborn organic matter from the binder from the surface of polished silicon carbide products. The second component of the cleaning agent, a combination of wetting agent alkyl glycoside and penetrant, softens and dissolves strongly adhesive binder components such as paraffin and rosin, allowing them to separate from the silicon carbide under ultrasonic or spraying force. The first component, a specific surfactant, emulsifies and disperses the organic matter in the binder, increasing its solubility in the system and preventing secondary contamination of the silicon carbide wafer. Simultaneously, the surfactant reduces the surface tension between the silicon carbide product surface, the cleaning agent, and the polishing abrasives, causing adsorbed and adhered abrasive particles to detach from the product surface. The pH adjuster in the cleaning agent adjusts the pH of the cleaning system to 10-14. Experiments have verified that the dissolution effect of the binder and the detachment effect of the polishing slurry are optimal under these conditions.

[0015] Other components, such as the metal scavenger in the second component, can effectively remove metal ions, especially iron ions, carried in the raw materials of the system and introduced during the production process; depending on the specific types of impurities attached to the surface of silicon carbide, other commonly used additives in the industry can also be added to achieve targeted impurity removal. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a comparison diagram of the metallographic detection effect at 1000X magnification in Embodiment 1 of the present invention; Figure 2 This is a comparison diagram of the metallographic detection effect at 1000X magnification in Embodiment 2 of the present invention; Figure 3 This is a comparison chart of the metallographic detection effect at 1000X magnification in Comparative Example 1 of the present invention; Figure 4 This is a comparison chart of the metallographic detection effect of Comparative Example 2 of the present invention at 1000X magnification. Detailed Implementation

[0018] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0019] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways than those described herein, and therefore the invention is not limited to the specific embodiments disclosed in the following specification.

[0020] Example 1, such as Figure 1 As shown, a cleaning agent capable of removing residues from the surface of polished silicon carbide comprises a first component of a nonionic surfactant, a second component of an anionic surfactant, a wetting agent, a penetrant, a dispersant, a metal scavenger, a pH adjuster, and pure water. By mass percentage of the cleaning agent, the nonionic surfactant is tridecyl isomeric alcohol polyoxyethylene ether (1309) 4 parts, the anionic surfactant is sodium dodecylbenzene sulfonate 6 parts, the wetting agent is alkyl glycoside (APG-0810) 2 parts, the penetrant (JFC-2) 3 parts, the dispersant is sodium pyrophosphate 4 parts, the metal scavenger is sodium citrate 2 parts, and the pH adjuster is sodium carbonate to adjust the pH of the cleaning agent to 10, with the remainder being water.

[0021] The specific preparation method of the cleaning agent in Example 1 is as follows: Add two-thirds of the required amount of pure water to the reaction vessel, add the first component while stirring, heat to 40-50℃, fully dissolve and disperse, add the second component, stir to dissolve, mix evenly, add pH adjuster, replenish water, and the pH value of the system is 10.

[0022] Example 2, as Figure 2 As shown, a cleaning agent capable of removing residues from the surface of polished silicon carbide comprises a first component of a nonionic surfactant, a second component of an anionic surfactant, a wetting agent, a penetrant, a dispersant, a metal scavenger, a pH adjuster, and pure water. By mass percentage of the cleaning agent, the nonionic surfactant is tridecyl isomeric alcohol polyoxyethylene ether (1309) 4 parts, the anionic surfactant is sodium dodecylbenzenesulfonate 6 parts, the dispersant is sodium pyrophosphate 4 parts, the wetting agent is alkyl glycoside (APG-0810) 2 parts, the penetrant (JFC-2) 3 parts, the metal scavenger is hydroxyethylidene diphosphonic acid 2 parts, and the pH adjuster is sodium hydroxide to adjust the pH of the cleaning agent to 13, with the remainder being water. The specific preparation method of the cleaning agent in Example 1 is as follows: Add two-thirds of the required amount of pure water to the reaction vessel, add the first component while stirring, heat to 40-50℃, fully dissolve and disperse, add the second component, stir to dissolve, mix evenly, add pH adjuster, replenish water, and the pH value of the system is 13.

[0023] Comparative Example 1 describes a silicon carbide cleaning agent comprising a first component (a nonionic surfactant), a second component (a wetting agent, penetrant, dispersant, metal trapping agent, and pH adjuster), and pure water. By mass percentage, the nonionic surfactant is tridecaisopropyl alcohol polyoxyethylene ether (1309) 4 parts, the anionic surfactant is sodium dodecylbenzenesulfonate 6 parts, the metal trapping agent is sodium citrate 3 parts, and the pH adjuster is sodium carbonate to adjust the pH of the cleaning agent to 10. The remainder is water. The process involves adding two-thirds of the required volume of pure water to a reaction vessel, adding the first component while stirring, heating to 40-50°C to fully dissolve and disperse, adding the second component, stirring to dissolve and mix evenly, adding the pH adjuster, and replenishing the water to achieve a system pH of 10.

[0024] Comparative Example 2 describes a silicon carbide cleaning agent comprising a first component (a nonionic surfactant), a second component (a wetting agent, penetrant, dispersant, metal scavenger, and pH adjuster), and pure water. By mass percentage, the nonionic surfactant is tridecaisopropyl alcohol polyoxyethylene ether (1309) 4 parts, the anionic surfactant is sodium dodecylbenzenesulfonate 6 parts, the wetting agent is alkyl glycoside (APG-0810) 2 parts, the metal scavenger is sodium citrate 3 parts, and the pH adjuster is sodium hydroxide to adjust the pH of the cleaning agent to 13. The remainder is water. The process involves adding two-thirds of the required volume of pure water to a reaction vessel, adding the first component while stirring, heating to 40-50°C to fully dissolve and disperse, adding the second component, stirring to dissolve and mix evenly, adding the pH adjuster, and replenishing the water to achieve a system pH of 13.

[0025] Performance verification was performed on a cleaning agent from this application capable of removing surface residues after silicon carbide polishing: Take 200 silicon carbide wafers with similar contamination conditions, divide them into four groups of 50 wafers each, and place them into four ultrasonic cleaning instruments. Add the products of Example 1, Example 2, Comparative Example 1 and Comparative Example 2 respectively, heat to 60°C, ultrasonically vibrate and clean for 20 minutes, and rinse three times in pure water.

[0026] Remove the cleaned silicon carbide wafers and dry them. Randomly select several silicon carbide wafers from each group for metallographic examination and filter paper scratch test: Metallographic testing: Passed Figures 1-4 The metallographic images show that the silicon carbide surface cleaned with the products of Comparative Example 1 and Comparative Example 2 had foreign matter and relatively poor uniformity after cleaning, while the surface cleaned with the products of Example 1 and Example 2 was more uniform, with a uniform color and no organic matter (wax or rosin) or abrasive residue on the surface.

[0027] Filter paper scratch test: Neutral filter paper was used to wipe the silicon carbide wafers cleaned with the products of Example 1, Example 2, and Comparative Examples 1 and 2, respectively. The results showed that after wiping the silicon carbide wafers cleaned with the products of Example 1 and Example 2, the surface of the filter paper remained white, without any abrasive powder or residue. However, after wiping the silicon carbide wafers cleaned with the products of Comparative Examples 1 and 2, a slight gray residue remained on the filter paper, indicating a slightly worse cleaning effect. When the product produced by this invention is used in the cleaning of silicon carbide, the surface of the silicon wafer is uniform and smooth after cleaning, without any abrasive, binder or other residues. After wiping with filter paper, there are no abrasive powder or other substances left behind. It can perfectly meet the production needs of customers. Moreover, the process is environmentally friendly, with no organic solvents added during the production process, and the product is environmentally friendly and pollution-free.

[0028] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A cleaning agent capable of removing residues from the surface of silicon carbide after polishing, characterized in that, It includes a first component, a second component, a pH adjuster, and water; the first component contains nonionic surfactants and anionic surfactants of isotridecyl alcohol polyoxyethylene ether or polyoxypropylene polyoxyethylene block; the second component contains wetting agents, penetrants, dispersants, and metal trapping agents. The cleaning agent, by mass parts, comprises 3-6 parts of nonionic surfactant and 4-10 parts of anionic surfactant in the first component, 1-3 parts of wetting agent, 0-6 parts of penetrant, 1-5 parts of metal trapping agent, 2-6 parts of dispersant in the second component, and the balance being water and pH adjuster; the pH adjuster is used to adjust the pH value of the cleaning agent to 10-14.

2. The cleaning agent according to claim 1, capable of removing surface residues after silicon carbide polishing, characterized in that, The nonionic surfactant of the first component is one or more of isotridecyl alcohol polyoxyethylene ether and polyoxypropylene polyoxyethylene ether; The anionic surfactant is one or more of dodecyl sulfonic acid, dodecylbenzene sulfonic acid, and their salts.

3. The cleaning agent according to claim 1, capable of removing surface residues after silicon carbide polishing, characterized in that, The wetting agent of the second component is an alkyl glycoside and a mixture thereof, including one or more of APG-0810, dodecyl glucoside, lauryl glucoside APG-1214, and lauryl glucoside APG-0814 glycoside; The penetrant of the second component is an alkyl alcohol polyoxyethylene ether with a chemical structure of C6-C10; The metal scavenging agent in the second component is one or more of EDTA, aminotriacetic acid, tartaric acid, citric acid, diethylenetriaminepentaacetic acid, hydroxyethylidene diphosphonic acid, and their salts. The dispersant for the second component is one or more of sodium pyrophosphate and potassium pyrophosphate.

4. The cleaning agent according to claim 1, capable of removing surface residues after silicon carbide polishing, characterized in that, The pH adjuster is one or more of sodium carbonate, sodium bicarbonate, sodium hydroxide, and potassium hydroxide.

5. A method for preparing a cleaning agent capable of removing surface residues after silicon carbide polishing according to any one of claims 1 to 4, characterized in that, The specific preparation method is as follows: Add two-thirds of the required amount of pure water to the reaction vessel, add the first component while stirring, heat to 40-50℃, fully dissolve and disperse, add the second component, stir to dissolve, mix evenly, add pH adjuster, and replenish water to control the final pH value of the system in the range of 10-14, thus obtaining the cleaning agent.

6. The application of the cleaning agent according to claim 1, which can remove surface residues after silicon carbide polishing, in the cleaning of silicon carbide.

7. The application of the cleaning agent according to claim 6, capable of removing surface residues after silicon carbide polishing, in the cleaning of silicon carbide, characterized in that, The cleaning agent is used at a temperature of 30-70℃ when cleaning silicon carbide; the cleaning time is 10-30 minutes.

8. The application of the cleaning agent according to claim 6, capable of removing surface residues after silicon carbide polishing, in the cleaning of silicon carbide, characterized in that, Silicon carbide is cleaned by immersion in cleaning agent, ultrasonic or megasonic oscillation, or by spraying or rinsing with cleaning reagent.

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