Method for cleaning crystals of silicon wafer polishing machine

Abstract

The invention relates to a method for cleaning crystals of a silicon wafer polishing machine, which belongs to the technical field of silicon wafer processing equipment cleaning, and comprises the following operation steps of: 1, before starting a mechanical cleaning assembly, stopping the operation of the polishing machine, and emptying residual polishing liquid in the polishing machine; and 2, controlling the displacement of the cutter through a telescopic cylinder, so that the rotary scraper and the vibration brush head are close to the polishing liquid crystal attachment part. Thirdly, mechanical cleaning is carried out, and a rotary scraper is started to preliminarily scrape large-area crystals; in the cleaning process of the scraper, the vibration brush head is started at the same time, further fine cleaning is conducted on the surface cleaned by the scraper, and residual crystal particles are removed. And fourthly, flushing is conducted after mechanical cleaning is completed, and water on the surfaces of the equipment components is blown dry through hot air. Under the condition that main parts of the device are not disassembled, crystal substances are rapidly and thoroughly removed, stable operation of the silicon wafer polishing machine is guaranteed, and production efficiency and silicon wafer polishing quality are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of cleaning of silicon wafer processing equipment, and particularly relates to a method for cleaning crystallization of a silicon wafer polishing machine. Background Art

[0002] Polishing machine equipment is a commonly used equipment in the process of semiconductor preparation. Due to the crystallization characteristics of the polishing liquid, when the polishing machine equipment works continuously, crystallization accumulates around the large disk to form hardening and hardening substances. If the crystallization substances fall into the Tank during the processing, there is a risk of causing dark scratches on the silicon wafer. Therefore, it is necessary to perform regular crystallization cleaning.

[0003] During the silicon wafer polishing process, chemical substances in the polishing liquid react with substances on the surface of the silicon wafer, and crystallization substances will be formed on the surfaces of components such as the polishing disc, polishing liquid circulation pipeline, and nozzle of the polishing machine. The existence of these crystallization substances brings many problems: (1) Affecting the polishing quality: Crystallization substances adhering to the surface of the polishing disc will change the flatness and roughness of the polishing disc, resulting in uneven stress on the silicon wafer during polishing, thereby generating defects such as scratches and uneven thickness on the surface of the silicon wafer, reducing the polishing quality and yield rate of the silicon wafer.

[0004] (2) Causing equipment failures: Crystallization substances accumulate in the polishing liquid circulation pipeline, which will reduce the inner diameter of the pipeline, hinder the normal flow of the polishing liquid, increase the pressure in the pipeline, and may cause serious problems such as pipeline rupture and joint loosening. Crystallization substances accumulate at the nozzle, causing the nozzle to be blocked, affecting the uniform spraying of the polishing liquid, and further affecting the polishing effect.

[0005] (3) Increasing maintenance costs: Currently, the cleaning of these crystallization substances mainly relies on manual disassembly of relevant components for cleaning, which is cumbersome, consumes a large amount of manpower and time. Frequent manual disassembly may also cause component damage, increasing equipment maintenance costs and downtime, and reducing production efficiency. Summary of the Invention

[0006] The present invention mainly solves the deficiencies existing in the prior art, and provides a method for cleaning crystallization of a silicon wafer polishing machine, which has the advantages of simple structure, good operation stability, time-saving and labor-saving, and solves the problems of difficult cleaning of crystallization substances, affecting polishing quality and equipment operation. Without disassembling the main components of the equipment, the crystallization substances can be quickly and thoroughly removed, ensuring the stable operation of the silicon wafer polishing machine, improving production efficiency and the polishing quality of the silicon wafer. Extend the service life of the polishing machine, reduce the downtime of the polishing machine, and improve the first-pass yield of product processing.

[0007] The above technical problems of the present invention are mainly solved by the following technical solutions: A cleaning method for the crystallization of a silicon wafer polishing machine. The cleaning device includes a polishing fixed disk, and a polishing ceramic disk is provided at the upper end of the polishing fixed disk. A polishing rotating shaft is installed on the polishing ceramic disk. A number of silicon wafers for the polishing process are provided between the polishing ceramic disk and the polishing fixed disk. A mechanical cleaning component for cleaning the polishing liquid crystallization on the side of the polishing ceramic disk is provided.

[0008] The mechanical cleaning component includes a tool holder. A tool in contact with the polishing liquid crystallization is provided at the front end of the tool holder. A telescopic cylinder is provided between the tool and the tool holder.

[0009] The tool includes a tool rod. A number of scraping blades distributed in a ring are provided at the front end of the tool rod. A brush head is provided on the outer circle of the front part of the tool rod. A bearing is provided between the brush head and the tool rod.

[0010] The cleaning method includes the following operating steps: The first step: Before starting the mechanical cleaning component, first stop the operation of the polishing machine and empty the residual polishing liquid in the polishing machine.

[0011] The second step: Control the displacement of the tool through the telescopic cylinder to make the rotating scraping blade and the vibrating brush head close to the attachment part of the polishing liquid crystallization.

[0012] The third step: Perform mechanical cleaning. Start the rotating scraping blade to initially scrape the large-area crystallization; during the scraping process of the scraping blade, at the same time start the vibrating brush head to further finely clean the surface after the scraping blade cleaning to remove the residual crystallization particles.

[0013] The fourth step: After the mechanical cleaning is completed, perform rinsing, and then use hot air to dry the moisture on the surface of the equipment components.

[0014] Preferably, a cleaning liquid storage tank is provided on the side of the mechanical cleaning component. A cleaning spray pipe extending above the tool is provided on the cleaning liquid storage tank. An infusion pump is provided between the cleaning spray pipe and the cleaning liquid storage tank. A waste liquid collection box is provided below the polishing fixed disk. When the mechanical cleaning is completed, start the infusion pump to spray the chemical cleaning liquid at a flow rate of 0.5 - 1 liter per minute through the nozzle at the front end of the cleaning spray pipe on the part that has undergone mechanical cleaning. The nozzle is installed on the periphery of the mechanical cleaning component and can accurately spray the cleaning liquid on the surface of the crystallization.

[0015] Preferably, let the cleaning liquid stay on the surface of the crystallization for 5 - 10 minutes to fully react with the residual crystallization to dissolve it; use deionized water to rinse the cleaning part, and control the rinsing water flow rate at 1 - 2 liters per minute to wash the dissolved crystallization and the chemical cleaning liquid into the waste liquid collection box.

[0016] Preferably, the cleaning liquid components in the cleaning liquid storage tank include organic acids, surfactants, and corrosion inhibitors. The organic acids can chemically react with the crystals to dissolve them; the surfactants enhance the penetration and dispersion ability of the cleaning liquid, improving the cleaning effect; and the corrosion inhibitors protect the equipment components from being corroded by the cleaning liquid.

[0017] Preferably, a cylinder mounting seat is provided between the tool holder and the telescopic cylinder, and a tool rotation motor for driving the tool rod to rotate is provided between the tool and the telescopic cylinder. The rotation speed of the tool rotation motor is 500 - 1000 revolutions per minute; a vibrator is provided between the front part of the tool rotation motor and the brush head. The vibration frequency of the vibrator is set to 50 - 100 Hz. The brush head is connected to the vibrator, and the brush head is made of rubber that is soft and has a certain friction force, and is used to clean the crystals in small gaps and corners that are difficult to reach by the scraper.

[0018] Preferably, the tool holder includes a column. A support plate is provided between the upper end of the column and the cylinder mounting seat, and a connecting plate integrally welded with the column is provided at the lower end of the column. A sliding cylinder is installed between the support plate and the column. The scraper can move flexibly in the horizontal and vertical directions through the sliding cylinder and the telescopic cylinder to adapt to the cleaning of crystals in different parts.

[0019] Preferably, a base is provided at the lower end of the connecting plate. An adjusting plate is provided between the base and the connecting plate. A fixing block is provided on one side of the upper end of the base, and a screw rod for threaded adjustment with the adjusting plate is provided on the fixing block.

[0020] The present invention can achieve the following effects: The present invention provides a method for cleaning crystals of a silicon wafer polishing machine. Compared with the prior art, it has the advantages of simple structure, good operation stability, time - saving and labor - saving, solves the problems of difficult crystal cleaning, affecting polishing quality and equipment operation. It prolongs the service life of the polishing machine, reduces the downtime of the polishing machine, and improves the first - pass yield of product processing.

[0021] Improve cleaning efficiency: The combination of mechanical cleaning and chemical cleaning can quickly and effectively remove crystals. Compared with traditional manual cleaning, the cleaning time is shortened by 60% - 80%, greatly improving the production efficiency.

[0022] Guarantee polishing quality: Timely and thoroughly remove crystals, avoid the influence of crystals on components such as the polishing disc, ensure the normal operation of the silicon wafer polishing machine, thereby improving the polishing quality of the silicon wafer and increasing the product yield rate.

[0023] The automated cleaning process reduces the workload of manual disassembly and cleaning, lowers labor costs and the risk of component damage caused by improper manual operation, extends the service life of the equipment, and reduces equipment maintenance costs.

[0024] Environmental protection and energy conservation: The waste liquid recovery system effectively treats the cleaning waste liquid, reduces environmental pollution, and meets environmental protection requirements. Moreover, there is no need to frequently replace equipment components, saving resources and achieving energy conservation goals. Brief Description of the Drawings

[0025] Figure 1 It is a schematic structural diagram of the present invention.

[0026] Figure 2 It is a schematic structural diagram of the mechanical cleaning component of the present invention.

[0027] Figure 3 It is a schematic structural diagram of the tool of the present invention.

[0028] Figure 4 It is a schematic structural diagram of the tool holder of the present invention.

[0029] In the figure: cleaning spray pipe 1, mechanical cleaning component 2, polishing ceramic disc 3, polishing rotating shaft 4, silicon wafer 5, polishing fixed disc 6, waste liquid collection tank 7, cleaning liquid storage tank 8, infusion pump 9, tool holder 10, telescopic cylinder 11, cylinder mounting seat 12, tool rotating motor 13, tool 14, vibrator 15, brush head 16, bearing 17, scraper 18, tool rod 19, column 20, support plate 21, connecting plate 22, adjusting plate 23, screw 24, fixing block 25, base 26. Detailed Description of the Invention

[0030] The technical solution of the invention will be further specifically described below through embodiments in conjunction with the drawings.

[0031] Embodiment: As Figures 1-4 shown, a method for cleaning the crystallization of a silicon wafer polishing machine, the cleaning device includes a polishing fixed disc 6, a polishing ceramic disc 3 is provided at the upper end of the polishing fixed disc 6, a polishing rotating shaft 4 is installed on the polishing ceramic disc 3, a plurality of silicon wafers 5 for the polishing process are provided between the polishing ceramic disc 3 and the polishing fixed disc 6, and a mechanical cleaning component 2 for cleaning the polishing liquid crystallization of the polishing ceramic disc 3 is provided on the side of the polishing ceramic disc 3.

[0032] The mechanical cleaning assembly 2 includes a tool holder 10. At the front end of the tool holder 10, there is a tool 14 that contacts the crystallization of the polishing liquid. Between the tool 14 and the tool holder 10, there is a telescopic cylinder 11. Between the tool holder 10 and the telescopic cylinder 11, there is a cylinder mounting seat 12. Between the tool 14 and the telescopic cylinder 11, there is a tool rotating motor 13 that drives the tool rod 19 to rotate. The rotation speed of the tool rotating motor 13 is 500 - 1000 revolutions per minute. At the front of the tool rotating motor 13, there is a vibrator 15 between the brush heads 16, and the vibration frequency of the vibrator 15 is set to 50 - 100 Hz.

[0033] The said tool 14 includes a tool rod 19. At the front end of the tool rod 19, there are several scraping blades 18 distributed in a ring. On the outer circle of the front part of the tool rod 19, there are brush heads 16. Between the brush heads 16 and the tool rod 19, there is a bearing 17.

[0034] The tool holder 10 includes a column 20. Between the upper end of the column 20 and the cylinder mounting seat 12, there is a support plate 21. At the lower end of the column 20, there is a connecting plate 22 integrally welded with the column 20. At the lower end of the connecting plate 22, there is a base 26. Between the base 26 and the connecting plate 22, there is an adjusting plate 23. On one side of the upper end of the base 26, there is a fixing block 25. On the fixing block 25, there is a screw rod 24 that is threadedly adjusted with the adjusting plate 23.

[0035] The cleaning method includes the following operating steps: The first step: Before starting the mechanical cleaning assembly 2, first stop the operation of the polishing machine and empty the residual polishing liquid in the polishing machine.

[0036] The second step: Control the displacement of the tool 14 through the telescopic cylinder 11 to make the rotating scraping blade 18 and the vibrating brush head 16 close to the attachment part of the polishing liquid crystallization.

[0037] The third step: Conduct mechanical cleaning. Start the rotating scraping blade 18 to initially scrape off the large - area crystals; during the scraping process of the scraping blade, at the same time start the vibrating brush head to further finely clean the surface after the scraping blade cleaning and remove the residual crystal particles.

[0038] The fourth step: After the mechanical cleaning is completed, conduct rinsing, and then use hot air to dry the moisture on the surface of the equipment components.

[0039] On the side of the mechanical cleaning component 2, there is a cleaning liquid storage tank 8. The cleaning liquid in the cleaning liquid storage tank 8 contains organic acids, surfactants, and corrosion inhibitors. The organic acids can chemically react with the crystals to dissolve them; the surfactants enhance the penetration and dispersion ability of the cleaning liquid to improve the cleaning effect; the corrosion inhibitors protect the equipment components from being corroded by the cleaning liquid. There is a cleaning spray pipe 1 extending above the tool 14 on the cleaning liquid storage tank 8. There is an infusion pump 9 between the cleaning spray pipe 1 and the cleaning liquid storage tank 8. There is a waste liquid collection tank 7 under the polishing platen 6. After the mechanical cleaning is completed, start the infusion pump, and spray the chemical cleaning liquid at a flow rate of 0.5 - 1 liter per minute through the nozzle at the front end of the cleaning spray pipe 1 onto the parts that have undergone mechanical cleaning.

[0040] Let the cleaning liquid stay on the surface of the crystals for 5 - 10 minutes to fully chemically react with the remaining crystals to dissolve them; use deionized water to rinse the cleaning part, and control the rinse water flow rate at 1 - 2 liters per minute to wash the dissolved crystals and the chemical cleaning liquid into the waste liquid collection tank 7.

[0041] Finally, check the cleaned parts through manual or automated inspection equipment to confirm whether the crystals are cleaned up. If there is still residue, repeat the above cleaning steps until the cleaning meets the standard.

[0042] In summary, the method for cleaning the crystallization of this wafer polishing machine has the advantages of simple structure, good operation stability, time - saving and labor - saving. It solves the problems of difficult crystallization cleaning, affecting the polishing quality and equipment operation. Without disassembling the main components of the equipment, it can quickly and thoroughly remove the crystals, ensure the stable operation of the wafer polishing machine, improve the production efficiency and the wafer polishing quality. It prolongs the service life of the polishing machine, reduces the downtime of the polishing machine, and improves the first - pass yield of product processing.

[0043] The above are only specific embodiments of the present invention, but the structural features of the present invention are not limited thereto. Any changes or modifications made by those skilled in the art within the scope of the present invention are covered by the patent scope of the present invention.

Claims

1. A method for cleaning crystals of a silicon wafer polishing machine, characterized in that: The cleaning device comprises a polishing plate (6), a polishing ceramic plate (3) is provided at the upper end of the polishing plate (6), a polishing shaft (4) is mounted on the polishing ceramic plate (3), a plurality of silicon wafers (5) for polishing are provided between the polishing ceramic plate (3) and the polishing plate (6), and a mechanical cleaning component (2) for cleaning the polishing ceramic plate (3) from crystallization of polishing liquid is provided on the side of the polishing ceramic plate (3); The mechanical cleaning assembly (2) comprises a tool support (10), the front end of the tool support (10) is provided with a tool (14) that contacts the polishing liquid crystal, and a telescopic cylinder (11) is provided between the tool (14) and the tool support (10); The tool (14) comprises a tool rod (19), a front end of the tool rod (19) is provided with a plurality of scrapers (18) distributed in an annular shape, a brush head (16) is provided on the front outer circle of the tool rod (19), and a bearing (17) is provided between the brush head (16) and the tool rod (19); The cleaning method includes the following steps: Step 1: Before starting the mechanical cleaning component (2), stop the polishing machine and drain the polishing liquid remaining in the polishing machine; Step 2: Control the displacement of the tool (14) by means of the telescopic cylinder (11) so that the rotating scraper (18) and the vibrating brush head (16) are close to the polishing liquid crystal attachment site; Step 3: Mechanical cleaning is performed by starting the rotating scraper (18) to preliminarily scrape off the large area of ​​crystals; during the scraper cleaning process, the vibrating brush head is simultaneously started to further finely clean the surface after the scraper cleaning to remove the remaining crystal particles; Step 4: After mechanical cleaning is completed, rinse and then use hot air to dry the moisture on the surface of the equipment parts.

2. The method for cleaning silicon wafer polishing machine crystals according to claim 1, characterized in that: A cleaning liquid storage tank (8) is provided on the side of the mechanical cleaning component (2), a cleaning nozzle (1) extending to the top of the tool (14) is provided on the cleaning liquid storage tank (8), an infusion pump (9) is provided between the cleaning nozzle (1) and the cleaning liquid storage tank (8), and a waste liquid collection box (7) is provided at the bottom of the polishing plate (6); when the mechanical cleaning is completed, the infusion pump is started to spray the chemical cleaning liquid at a flow rate of 0.5 to 1 liter / minute through the nozzle at the front end of the cleaning nozzle (1) onto the part that has been mechanically cleaned.

3. The cleaning method for silicon wafer polishing machine crystal according to claim 2, characterized in that: The cleaning liquid is allowed to remain on the surface of the crystals for 5 to 10 minutes to fully react chemically with the remaining crystals to dissolve them; the cleaning area is rinsed with deionized water, and the flow rate of the rinse water is controlled at 1 to 2 liters / minute, and the dissolved crystals and chemical cleaning liquid are rinsed into the waste liquid collection box (7).

4. The method for cleaning silicon wafer polishing machine crystals according to claim 2, characterized in that: The cleaning liquid in the cleaning liquid storage tank (8) includes organic acid, surfactant and corrosion inhibitor. The organic acid can react chemically with the crystals to dissolve them; the surfactant enhances the penetration and dispersion ability of the cleaning liquid and improves the cleaning effect; and the corrosion inhibitor protects the equipment components from being corroded by the cleaning liquid.

5. The method for cleaning silicon wafer polishing machine crystals according to claim 1, characterized in that: A cylinder mounting seat (12) is provided between the tool support (10) and the telescopic cylinder (11); a tool rotating motor (13) for driving the tool rod (19) to rotate is provided between the tool (14) and the telescopic cylinder (11); the rotation speed of the tool rotating motor (13) is 500 to 1000 revolutions per minute; a brush head (16) is provided at the front of the tool rotating motor (13); a vibrator (15) is provided between the brush head (16); the vibration frequency of the vibrator (15) is set to 50 to 100 Hz.

6. The method for cleaning the silicon wafer polishing machine crystal according to claim 5, characterized in that: The tool support (10) comprises a column (20), a support plate (21) is provided between the upper end of the column (20) and the cylinder mounting seat (12), and a connecting plate (22) is provided at the lower end of the column (20) and is integrally welded to the column (20).

7. The method for cleaning silicon wafer polishing machine crystals according to claim 6, characterized in that: A base (26) is provided at the lower end of the connecting plate (22), an adjusting plate (23) is provided between the base (26) and the connecting plate (22), a fixing block (25) is provided at one side of the upper end of the base (26), and a screw (24) is provided on the fixing block (25) for threaded adjustment with the adjusting plate (23).

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