Process for cleaning large-size silicon wafer after final polishing

Abstract

The invention provides a process for cleaning a large-size silicon wafer after final polishing, which comprises five processing processes of surface protection, pretreatment, scrubbing, rotary spraying and drying, and comprises the following steps: 1) surface protection: firstly, treating the polished silicon wafer by using a cleaning solution 1 to improve the surface hydrophilicity of the silicon wafer; 2) pretreatment: spraying the surface of the silicon wafer by using a cleaning solution 2; 3) scrubbing: scrubbing the silicon wafer by using a cleaning solution 3 in cooperation with a brush to remove particles attached to the surface of the silicon wafer; 4) rotary spraying: cleaning the silicon wafer by utilizing the cleaning solution 4 to cooperate with the rotation of the silicon wafer, and flushing with ozone water and pure water; and 5) drying: drying the silicon wafer in a manner of spin-drying and nitrogen purging. By means of the cleaning technology, the finally obtained polished wafer has high surface cleanliness, the cleaning cost is low, and environmental pollution is small.

Description

Technical Field

[0001] The invention belongs to the technical field of cleaning semiconductor large silicon wafers after polishing, and in particular relates to a cleaning process for large-size silicon wafers after final polishing. Background Art

[0002] With the rapid development of ultra-large-scale integrated circuit process capabilities, the line width size has been further reduced, the cleanliness requirements for polishing wafers have become increasingly higher, and higher requirements have been placed on the processing technology.

[0003] At present, the mainstream cleaning processes are mainly tank cleaning and single-wafer cleaning. Compared with tank cleaning, single-wafer cleaning has the advantages of strong cleaning ability, high consistency of cleaning effect, strong traceability, etc. In addition, the single-wafer cleaning machine can be used online with the final polishing machine to achieve the effect of dry in and dry out, avoiding the pollution caused by the water truck storage process after the silicon wafer is polished, and has extremely high use value.

[0004] However, the particle size and surface metal content of the silicon wafer surface cleaned by the current final post-polishing cleaning process are still not ideal, and the yield of products meeting specifications below 19nm is low, which cannot meet the needs of mass production. Summary of the invention

[0005] The invention provides a cleaning process for large-size silicon wafers after final polishing. The polished wafers prepared by the process have higher surface cleanliness, lower cleaning cost and less environmental pollution.

[0006] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solution:

[0007] A large-size silicon wafer cleaning process after final polishing comprises the following steps:

[0008] 1) Surface protection: The polished silicon wafer is first treated with cleaning solution 1 to improve the hydrophilicity of the silicon wafer surface;

[0009] 2) Pretreatment: spraying the surface of the silicon wafer with cleaning liquid 2;

[0010] 3) Scrubbing: Scrubbing the silicon wafer with a cleaning solution 3 and a brush to remove particles attached to the surface of the silicon wafer;

[0011] 4) Rotary spraying: The silicon wafer is cleaned by using cleaning liquid 4 in combination with the rotation of the silicon wafer, followed by cleaning with ozone water, and finally rinsed with pure water;

[0012] 5) Drying: Dry the silicon wafer by spinning and nitrogen purging.

[0013] In a specific embodiment, the cleaning solution 1 in step 1) is a surfactant dilution solution, the dilution ratio is 1:50-100, the flow rate is 0.5-1.5 L / min, and the processing time is 50-70 s.

[0014] In a preferred embodiment, the dilution ratio of the cleaning solution 1 to the surfactant diluent in step 1) is 1:80, the flow rate is 1.0 L / min, and the processing time is 60 s.

[0015] In a specific embodiment, the cleaning liquid 2 in step 2) is ozone water, wherein the ozone concentration is 10-20 ppm, the flow rate is 0.9-1.5 L / min, and the treatment time is 50-70 s.

[0016] In a preferred embodiment, the ozone concentration in step 2) is 15 ppm, the flow rate is 1.2 L / min, and the treatment time is 60 s.

[0017] In a specific implementation scheme, in the step 3), the silicon wafer is placed vertically, the brush is placed horizontally, there are three brushes, which are used to brush the front, back and edge of the silicon wafer respectively; the cleaning liquid 3 is pure water or SC-1, wherein the resistivity of pure water is greater than 18.2MΩ, and the volume ratio of SC-1 is NH4OH:H2O2:H2O=1:1:120-1:2:100; the flow rate of the cleaning liquid is 2-4L / min; the silicon wafer rotation speed is 5-15rpm; the brush rotation speed is 40-80rpm; and the processing time is 30-50s.

[0018] In a preferred embodiment, the cleaning liquid 3 in step 3) is SC-1, wherein the volume ratio of SC-1 is NH4OH:H2O2:H2O=1:1:100, the cleaning liquid flow rate is 3L / min; the silicon wafer rotation speed is 10rpm; the brush rotation speed is 60rpm; and the processing time is 40s.

[0019] In a specific embodiment, the cleaning liquid 4 in step 4) is a mixture of hydrofluoric acid and ozone water, wherein the ozone concentration is 10-20ppm, the mass fraction of hydrofluoric acid is 0.5-1.5wt%, the flow rate is 0.5-1.5L / min, and the treatment time is 60±20s; the rotation speed of the silicon wafer is 800-1200rpm; then, the ozone water is used for cleaning, the ozone concentration in the ozone water is 10-20ppm, the flow rate is 0.5-1.5L / min, and the treatment time is 10-20s; finally, pure water is used for rinsing for 10-20s.

[0020] In a preferred embodiment, the ozone concentration in the cleaning liquid 4 of hydrofluoric acid and ozone water mixture in step 4) is 15ppm, the mass fraction of hydrofluoric acid is 1.0wt%, the flow rate is 1.0L / min, and the processing time is 60s; the silicon wafer rotation speed is 1000rpm; then the ozone water is used for cleaning, the ozone concentration in the ozone water is 15ppm, the flow rate is 1.0L / min, and the processing time is 15s; finally, pure water is used for rinsing for 15s.

[0021] In a specific embodiment, in step 5), the spin-drying speed is 1000-2000 rpm, and the nitrogen flow rate is 15-20 L / min.

[0022] In a preferred embodiment, the spin-drying speed is 1500 rpm and the nitrogen flow rate is 20 L / min.

[0023] All silicon wafer transfer and support mechanisms used in the present invention may be any feasible known structures, and are not the focus of the present invention, and will not be described in detail here.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1) The present invention first uses a surfactant treatment to improve the hydrophilicity of the silicon wafer surface, reduce the impact of the external environment on the silicon wafer surface, and at the same time make it easier to remove particles attached to the silicon wafer surface, thereby reducing the difficulty of cleaning the silicon wafer.

[0026] 2) The present invention uses ozone water to pre-treat the silicon wafer, using the strong oxidizing property of ozone to remove residual organic matter on the surface of the silicon wafer, and at the same time can form a uniform and dense oxide film on the surface of the silicon wafer, providing a better surface state for subsequent cleaning and improving cleaning efficiency.

[0027] 3) The present invention adopts a vertical brushing method to clean silicon wafers. Compared with horizontal placement of silicon wafers, when silicon wafers are placed vertically, the cleaning conditions on both sides of the silicon wafers are consistent and the same cleaning effect can be achieved. Due to the effect of gravity, the particles peeled off by the brush can be more easily removed under the flushing effect of the cleaning liquid. Only pure water or ultra-low concentration SC-1 can be used as the cleaning liquid to achieve a good particle removal effect. At the same time, the use of pure water or ultra-low concentration SC-1 can minimize the corrosion of the alkaline solution on the surface of the silicon wafer, and can significantly reduce costs and reduce environmental pollution.

[0028] 4) The present invention uses a mixed solution of hydrofluoric acid and ozone water in combination with rotary spraying for cleaning, and the pollutants removed by cleaning are directly discharged with the cleaning liquid, avoiding the risk of pollutants dropped during the tank cleaning process remaining in the tank body and eventually being adsorbed by the silicon wafer again; at the same time, compared with the method of using HF acid and ozone water for circulating treatment, when the HF and ozone water mixed solution is used as the cleaning liquid, the oxidation and corrosion of the silicon wafer surface are carried out simultaneously, which can greatly improve the cleaning efficiency and improve the cleaning ability.

[0029] 5) In the scrubbing process, in addition to scrubbing the front and back sides of the silicon wafer, the present invention also adds an edge scrubbing brush to ensure the overall cleanliness of the silicon wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the process of cleaning a large-size silicon wafer after final polishing according to the present invention. DETAILED DESCRIPTION

[0031] In order to better understand the technical solution of the present invention, the following examples will further illustrate the method provided by the present invention, but the present invention is not limited to the listed examples, and should also include any other known changes within the scope of the claims of the present invention.

[0032] like Figure 1 As shown, a large-size silicon wafer cleaning process after final polishing includes surface protection, pretreatment, scrubbing, rotary spraying and drying processes, and specifically includes the following process steps:

[0033] 1) Surface protection: The polished silicon wafer is first treated with a surfactant to improve the hydrophilicity of the silicon wafer surface.

[0034] The final polishing of the silicon wafer can be performed on all currently known final polishing machines, such as the Okamoto final polishing machine, and the polishing process uses the equipment standard process. The polished silicon wafer is first treated with a cleaning solution 1. Wherein, the cleaning solution 1 is a surfactant diluent, and the dilution ratio (volume ratio) is 1:50-100, for example, including but not limited to 1:60, 1:70, 1:80, 1:90, 1:100, preferably 1:80; the flow rate is 0.5-1.5L / min, for example, including but not limited to 0.5L / min, 0.8L / min, 1.0L / min, 1.2L / min, 1.5L / min, preferably 1.0L / min; the processing time is 50-70s, including but not limited to 50s, 60s, 70s, preferably 60s.

[0035] The above process can improve the hydrophilicity of the silicon wafer surface and reduce environmental impact.

[0036] 2) Then, pretreatment is performed by spraying the surface of the silicon wafer with cleaning liquid 2.

[0037] Among them, the cleaning liquid 2 used is ozone water, wherein the ozone concentration is 10-20ppm, for example, including but not limited to 10ppm, 12ppm, 15ppm, 18ppm, 20ppm, preferably 15ppm; the flow rate is 0.9-1.5L / min, for example, including but not limited to 0.9L / min, 1.2L / min, 1.5L / min, preferably 1.2L / min; the processing time is 50-70s, including but not limited to 50s, 55s, 60s, 65s, 70s, preferably 60s.

[0038] Through the above process, residual organic matter on the surface of the silicon wafer can be removed while forming a uniform and dense oxide film on the surface of the silicon wafer, thereby improving the subsequent cleaning efficiency.

[0039] 3) The silicon wafer is then scrubbed using pure water or SC-1 as a cleaning liquid with a brush to remove particles attached to the surface of the silicon wafer.

[0040] There are three brushes, which are used to clean the front, back and edges of the silicon wafer respectively, so as to ensure the overall cleanliness of the silicon wafer; the silicon wafer is placed vertically and the brushes are placed horizontally, which can maximize the use of gravity and reduce the difficulty of cleaning.

[0041] Specifically, the cleaning liquid is pure water (resistivity > 18.2MW) or SC-1, wherein the ratio of SC-1 is NH4OH:H2O2:H2O=1:1:120-1:2:100, including but not limited to 1:1:120, 1:1:100, 1:2:100, preferably 1:1:100; the cleaning liquid flow rate is 2-4L / min, including but not limited to 2L / min, 3L / min, 4L / min, preferably 3L / min; the silicon wafer rotation speed is 5-15rpm, including but not limited to 5rpm, 8rpm, 10rpm, 12rpm, 15rpm, preferably 10rpm; the brush rotation speed is 40-80rpm, including but not limited to 40rpm, 50rpm, 60rpm, 70rpm, 80rpm, preferably 60rpm; the processing time is 30-50s, including but not limited to 30s, 35s, 40s, 45s, 50s, preferably 40s.

[0042] The above process can effectively remove large particles attached to the surface of the silicon wafer.

[0043] 4) The silicon wafer is then subjected to a rotational spraying, and the silicon wafer is cleaned by a mixture of hydrofluoric acid and ozone water in conjunction with the rotation of the silicon wafer, and then cleaned with ozone water, and finally rinsed with pure water.

[0044] During the cleaning process, the speed of the silicon wafer is 800-1200rpm, including but not limited to 800rpm, 900rpm, 1000rpm, 1100rpm, 1200rpm, preferably 100rpm. First, it is cleaned with a mixture of HF acid and ozone water. The ozone concentration in the HF acid and ozone mixture used is 10-20ppm, including but not limited to 10ppm, 11ppm, 12ppm, 13ppm, 14ppm, 15ppm, 16ppm, 17ppm, 18ppm, 19ppm, 20ppm, preferably 15ppm; the mass fraction of HF acid is 0.5-1.5wt%, including but not limited to 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1.0wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, preferably 1.0wt%; flow rate is 0.5-1.5L / min, including but not limited to 0.5L / min, 0.6L / min, 0.7L / min, 0.8L / min, 0.9L / min, 1.0L / min, 1.1L / min, 1.2L / min, 1.3L / min, 1.4L / min, 1.5L / min, preferably 1.0L / min; processing time is 60±20s, including but not limited to 40s, 50s, 60s, 70s, 80s, preferably 60s. Then, it is washed with ozone water, wherein the ozone concentration in the ozone water is 10-20ppm, including but not limited to 10ppm, 12ppm, 15ppm, 17ppm, 20ppm, preferably 15ppm; the flow rate is 0.5-1.5L / min, including but not limited to 0.5L / min, 0.6L / min, 0.7L / min, 0.8L / min, 0.9L / min, 1.0L / min, 1.1L / min, 1.2L / min, 1.3L / min, 1.4L / min, 1.5L / min, preferably 1.0L / min; the treatment time is 10-20s, including but not limited to 10s, 12s, 15s, 18s, 20s, preferably 15s. Finally, it is rinsed with pure water for 10-20s, including but not limited to 10s, 12s, 15s, 18s, 20s, preferably 15s.

[0045] The above process can effectively remove particles attached to the surface of silicon wafers and significantly reduce the level of metal contamination on the surface of silicon wafers. Finally, a hydrophilic silicon dioxide layer can be formed on the surface of silicon wafers, effectively reducing the attachment of pollutants and improving drying efficiency.

[0046] 5) Finally, the silicon wafer is dried by spin drying combined with nitrogen purging.

[0047] Wherein, the spin-drying speed is 1000-2000rpm, including but not limited to 1000rpm, 1200rpm, 1500rpm, 1800rpm, 2000rpm, preferably 1500rpm; the nitrogen flow rate is 15-20L / min, including but not limited to 15L / min, 18L / min, 20L / min, preferably 20L / min.

[0048] Compared with the prior art, the present invention adopts the method of vertical brushing + rotary spraying to clean silicon wafers. Compared with the horizontal placement of silicon wafers, the cleaning conditions on both sides of the silicon wafers are consistent when the silicon wafers are placed vertically, and the same cleaning effect can be achieved. Due to the effect of gravity, the particles peeled off by the brush can be more easily removed under the flushing effect of the cleaning liquid. Only pure water or ultra-low concentration SC-1 can be used as the cleaning liquid to achieve a better particle removal effect. At the same time, the use of pure water or ultra-low concentration SC-1 can minimize the corrosion of the alkaline solution on the surface of the silicon wafer, and can also significantly reduce costs and reduce environmental pollution. A mixed solution of HF acid and ozone water is used in combination with rotary spraying for cleaning. The pollutants removed by cleaning are directly discharged with the cleaning liquid, avoiding the risk of pollutants falling in the tank body during the tank cleaning process and being adsorbed by the silicon wafer again. At the same time, compared with the method of using HF acid and ozone water for circulating treatment, the use of a mixed solution of hydrofluoric acid and ozone water as the cleaning liquid can oxidize and corrode the silicon wafer surface at the same time, which can greatly improve the cleaning efficiency and cleaning ability.

[0049] The polishing process of the present invention is described in detail below in conjunction with more specific embodiments, but does not constitute any limitation.

[0050] Raw materials: 100 300mm COP-Free monocrystalline silicon wafers, crystal phase <100> , thickness 775±5μm.

[0051] Equipment: Final polisher, POST-CMP cleaning machine, SP5 particle size tester, ICP-MS metal tester.

[0052] Auxiliary materials: surfactant (Seiko Drynon-C), ozone, HF, hydrogen peroxide and ammonia water are all commercially available commodities.

[0053] Test method: Particle size test uses SP5, metal test uses ICP-MS.

[0054] Example 1

[0055] After the final polishing, the silicon wafer is firstly treated with a surfactant dilution to improve the hydrophilicity of the silicon wafer surface, wherein the surfactant dilution ratio is 1:80; the flow rate is 1.0 L / min; and the treatment time is 60 s.

[0056] Subsequently, the surface of the silicon wafer was sprayed with ozone water, the liquid used was ozone water, the ozone concentration was 15ppm, the flow rate was 1.2L / min, and the treatment time was 60s.

[0057] Then the silicon wafer was brushed, and the front, back and edges of the silicon wafer were brushed respectively. The silicon wafer was placed vertically and the brush was placed horizontally. The cleaning liquid used was SC-1, and the ratio of SC-1 was NH4OH:H2O2:H2O=1:1:100. The cleaning liquid flow rate was 3L / min, the silicon wafer rotation speed was 10rpm, the brush rotation speed was 60rpm, and the processing time was 40s.

[0058] The silicon wafer was then subjected to a rotary spraying, and a hydrofluoric acid and ozone mixed solution was used to clean the silicon wafer in coordination with the silicon wafer rotation. The ozone concentration in the hydrofluoric acid and ozone mixed solution used was 15ppm, the mass fraction of hydrofluoric acid was 1.0wt%, the flow rate was 1.0L / min, the processing time was 60s, and the silicon wafer rotation speed was 1000rpm. It was then rinsed with ozone water, with an ozone concentration of 15ppm, a flow rate of 1.0L / min, and a rinsing time of 15s. Finally, it was rinsed with pure water for 15s.

[0059] Finally, the silicon wafer was dried by spin drying combined with nitrogen purging, with a spin drying speed of 1500 rpm and a nitrogen flow rate of 20 L / min.

[0060] The particle size and surface metal content of the obtained silicon wafer were measured. The particle size of the obtained silicon wafer was >19nm≤30ea, and the surface metal content was <1E8 atoms / cm 2 .

[0061] Implementation 2

[0062] After the final polishing, the silicon wafer is firstly treated with a surfactant dilution to improve the hydrophilicity of the silicon wafer surface, wherein the surfactant dilution ratio is 1:100; the flow rate is 1.0 L / min; and the treatment time is 60 s.

[0063] Subsequently, ozone water was used to spray the surface of the silicon wafer. The liquid used was ozone water, with an ozone concentration of 20 ppm, a flow rate of 1.0 L / min, and a treatment time of 60 s.

[0064] Then the silicon wafer was brushed, and the front, back and edges of the silicon wafer were brushed respectively. The silicon wafer was placed vertically and the brush was placed horizontally. The cleaning liquid used was SC-1, and the ratio of SC-1 was NH4OH:H2O2:H2O=1:2:100. The cleaning liquid flow rate was 3L / min, the silicon wafer rotation speed was 10rpm, the brush rotation speed was 60rpm, and the processing time was 40s.

[0065] The silicon wafer was then subjected to a rotary spraying, and the silicon wafer was cleaned with a mixed solution of hydrofluoric acid and ozone in coordination with the rotation of the silicon wafer. The ozone concentration in the mixed solution of hydrofluoric acid and ozone used was 20ppm, the mass fraction of HF acid was 1.0wt%, the flow rate was 1.0L / min, the processing time was 60s, and the silicon wafer rotation speed was 1000rpm. It was then rinsed with ozone water, with an ozone concentration of 20ppm, a flow rate of 1.0L / min, and a rinsing time of 20s. Finally, it was rinsed with pure water for 20s.

[0066] Finally, the silicon wafer was dried by spin drying combined with nitrogen purging, with a spin drying speed of 1500 rpm and a nitrogen flow rate of 20 L / min.

[0067] The particle size and surface metal content of the obtained silicon wafer were measured. The particle size of the obtained silicon wafer was >19nm≤30ea, and the surface metal content was <1E8 atoms / cm 2 .

[0068] Comparative Example 1

[0069] Compared with Example 1, the silicon wafer was not treated with surfactant while other process conditions remained unchanged. The particle size and metal content of the obtained silicon wafer were measured. The particle size of the obtained silicon wafer was >19nm≤40ea, and the surface metal content was <1E8 atoms / cm 2 .

[0070] Comparative Example 2

[0071] Compared with Example 1, the silicon wafer is not subjected to the rotary spraying treatment while other process conditions remain unchanged. The particle size and metal content of the obtained silicon wafer are measured. The particle size of the obtained silicon wafer is >19nm≤60ea, and the surface metal all metal is <5E9 atoms / cm 2 .

[0072] Comparative Example 3

[0073] Compared with Example 1, under the condition that other process conditions remain unchanged, the silicon wafer is not subjected to brushing treatment. The particle size and metal content of the obtained silicon wafer are measured, and the particle size of the obtained silicon wafer is >19nm≤100ea, and the surface metal all metal is <1E9 atoms / cm 2 .

[0074] Comparative Example 4

[0075] Compared with Example 1, under the condition that other process conditions remain unchanged, the silicon wafer is placed horizontally during the scrubbing. The particle size and metal content of the obtained silicon wafer are measured. The particle size of the obtained silicon wafer is >19nm≤40ea, and the surface metal all metal is <3E8 atoms / cm 2 .

[0076] Comparative Example 5

[0077] Compared with Example 1, under the condition that other process conditions remain unchanged, the HF aqueous solution and the ozone aqueous solution are used for the same process time. The particle size and metal content of the obtained silicon wafer are measured. The particle size of the obtained silicon wafer is> 19nm≤40ea, and the surface metal all metal is <5E8 atoms / cm 2 .

[0078] The polishing sheets obtained in the embodiment and the comparative example were tested for particle size, and particle data and metal contaminant data were obtained. It can be seen from the data that the particle size and metal contaminant situation obtained by the polishing process of the embodiment of the present invention are better than those of the comparative example.

[0079] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as limiting the present invention. Those skilled in the art will appreciate that, under the guidance of this specification, some modifications or adjustments may be made to the present invention. These modifications or adjustments should also be within the scope defined by the claims of the present invention.

Claims

1. A large-size silicon wafer cleaning process after final polishing, characterized in that: The following steps are involved: 1) Surface protection: The polished silicon wafer is first treated with cleaning solution 1 to improve the hydrophilicity of the silicon wafer surface; 2) Pretreatment: spraying the surface of the silicon wafer with cleaning liquid 2; 3) Scrubbing: Scrubbing the silicon wafer with a brush using the cleaning solution 3 to remove particles attached to the surface of the silicon wafer; 4) Rotary spraying: The silicon wafer is cleaned by using cleaning liquid 4 in combination with the rotation of the silicon wafer, followed by cleaning with ozone water, and finally rinsed with pure water; 5) Drying: Dry the silicon wafer by spinning and nitrogen purging.

2. The large-size silicon wafer cleaning process after final polishing according to claim 1, characterized in that: The cleaning solution 1 in step 1) is a surfactant dilution solution, the dilution ratio is 1:50-100, the flow rate is 0.5-1.5 L / min, and the processing time is 50-70 s.

3. The large-size silicon wafer cleaning process after final polishing according to claim 2, characterized in that: The dilution ratio of the surfactant diluent is 1:80, the flow rate is 1.0 L / min, and the processing time is 60 s.

4. The large-size silicon wafer cleaning process after final polishing according to claim 1, characterized in that: In step 2), the cleaning liquid 2 is ozone water, wherein the ozone concentration is 10-20 ppm, the flow rate is 0.9-1.5 L / min, and the treatment time is 50-70 s.

5. The large-size silicon wafer cleaning process after final polishing according to claim 4, characterized in that: The ozone concentration is 15 ppm, the flow rate is 1.2 L / min, and the treatment time is 60 s.

6. The large-size silicon wafer cleaning process after final polishing according to claim 1, characterized in that: In step 3), the silicon wafer is placed vertically and the brush is placed horizontally. There are three brushes for brushing the front, back and edge of the silicon wafer respectively; the cleaning liquid 3 is pure water or SC-1, wherein the resistivity of pure water is greater than 18.2MΩ, and the volume ratio of SC-1 is NH4OH:H2O2:H2O=1:1:120-1:2:100; the flow rate of the cleaning liquid 3 is 2-4L / min; the silicon wafer rotation speed is 5-15rpm; the brush rotation speed is 40-80rpm; and the processing time is 30-50s.

7. The large-size silicon wafer cleaning process after final polishing according to claim 6, characterized in that: In step 3), the cleaning liquid 3 is SC-1, wherein the volume ratio of SC-1 is NH4OH:H2O2:H2O=1:1:100, the flow rate of the cleaning liquid 3 is 3L / min; the silicon wafer rotation speed is 10rpm; the brush rotation speed is 60rpm; and the processing time is 40s.

8. The large-size silicon wafer cleaning process after final polishing according to claim 1, characterized in that: The cleaning solution 4 in step 4) is a mixture of hydrofluoric acid and ozone water, wherein the ozone concentration is 10-20ppm, the mass fraction of hydrofluoric acid is 0.5-1.5wt%, the flow rate is 0.5-1.5L / min, and the processing time is 60±20s; the rotation speed of the silicon wafer is 800-1200rpm; and / or In the cleaning with ozone water, the ozone concentration in the ozone water is 10-20 ppm, the flow rate is 0.5-1.5 L / min, and the treatment time is 10-20 s; and / or Finally, rinse with pure water for 10-20 seconds.

9. The large-size silicon wafer cleaning process after final polishing according to claim 8, characterized in that: The cleaning solution 4 in step 4) is a mixture of hydrofluoric acid and ozone water, wherein the ozone concentration is 15 ppm, the mass fraction of hydrofluoric acid is 1.0 wt%, the flow rate is 1.0 L / min, and the processing time is 60 s; the silicon wafer rotation speed is 1000 rpm; and / or In the cleaning with ozone water, the ozone concentration in the ozone water is 15 ppm, the flow rate is 1.0 L / min, and the treatment time is 15 s; and / or Finally, rinse with pure water for 15 seconds.

10. The large-size silicon wafer cleaning process after final polishing according to claim 1, characterized in that: In the step 5), the drying speed is 1000-2000 rpm and the nitrogen flow rate is 15-20 L / min; Preferably, the spin-drying speed is 1500 rpm and the nitrogen flow rate is 20 L / min.

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