Enhanced cleaning method for large-size wafer

Abstract

The invention provides an enhanced cleaning method for a large-size wafer, and belongs to the technical field of semiconductor manufacturing. According to the invention, most of grinding fluid residues on the surface of the wafer can be washed away by directly entering the cleaning brush unit I, namely, brushing with a brush and cleaning with a hydrofluoric acid and deionized water mixed solution, and rough cleaning is carried out in a strong acid state. When the wafer just goes out of the grinding area, the grinding liquid and other chemical residues on the surface of the wafer can be brushed by the brush more quickly in the first time, and the cleaning effect of rough cleaning is improved under the action of hydrofluoric acid. According to the invention, the speed of removing the grinding fluid residues on the surface of the wafer is increased, further etching of the residues on the surface of the wafer is reduced, and the problem of inconsistent etching amount is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor manufacturing, and in particular to an enhanced cleaning method for large-size wafers. Background Art

[0002] Wafer cleaning is extremely important in the semiconductor industry. After CMP (Chemical Mechanical Planning) grinding, deionized water is usually used to remove particles. Some grinding liquid residues, metal ions, etc. must be cleaned with acidic solutions and mechanical rotation. For example, particles, slurry residues, chemical residues, buried particles, etc. have a certain impact on the yield of wafers. The current chemical cleaning of CMP is a method of using various chemical reagents and organic solvents to remove impurities attached to the surface of an object. In the field of semiconductor manufacturing, chemical cleaning refers to the process of removing various harmful impurities adsorbed on the surface of semiconductors, metal materials, and tools. Wafer cleaning is a process of removing dirt from the entire batch or a single wafer by chemical cleaning, by soaking or spraying chemicals. Its main purpose is to remove pollutants on the surface of the wafer, such as dust particles, organic matter, inorganic matter, and metal ions.

[0003] Generally, the cleaning method after chemical mechanical polishing is divided into the following steps: after the wafer is polished, it enters the cleaning area, the wafer enters the megasonic cleaning unit for horizontal rotation cleaning, the surface is sprayed with ammonia and hydrogen peroxide mixture for ultrasonic cleaning, the wafer enters the cleaning brush unit 1, the wafer is clamped up and down with a brush and rotated, and cleaned with a mixture of deionized water and hydrofluoric acid, the wafer enters the cleaning unit 2, the wafer is clamped up and down with a brush and rotated, and cleaned with a mixture of deionized water and ammonia, the wafer enters the spin-drying unit, cleaned with deionized water, and spin-dried with nitrogen and high-speed spin-drying action, after the spin-drying is completed, the wafer is transferred back to the wafer box. In the existing method, when the wafer enters the megasonic cleaning unit after polishing, the residual grinding liquid on the surface of the wafer is cleaned slowly, resulting in inconsistent etching amount on the surface of the wafer. Summary of the invention

[0004] The present invention provides a large-size wafer enhanced cleaning method to solve the problem of low cleaning efficiency and inconsistent etching amount caused by the existing method.

[0005] In a first aspect, the present invention provides an enhanced cleaning method for large-size wafers, which is applied to a cleaning system, wherein the cleaning system includes a first scrubbing unit, a megasonic cleaning unit, a second scrubbing unit and a spin-drying unit; the cleaning method includes: transferring the ground large-size wafer to the first scrubbing unit; in the first scrubbing unit, rotating the wafer, and using deionized water and hydrofluoric acid to perform a first scrubbing with a fixed cleaning brush; while the wafer is rotating, performing megasonic cleaning and a second scrubbing on the wafer after the first scrubbing; in the spin-drying unit, while the wafer is rotating, cleaning and drying the wafer by using deionized water, nitrogen blowing, and spraying isopropyl alcohol to complete the cleaning of the large-size wafer.

[0006] In a possible implementation, the megasonic cleaning and the second brush cleaning of the wafer after the first brush cleaning while the wafer is rotating includes: transferring the wafer after the first brush cleaning to a megasonic cleaning unit; in the megasonic cleaning unit, rotating the wafer and performing megasonic cleaning on the wafer surface with a mixture of ammonia water, hydrogen peroxide and deionized water; transferring the wafer after the megasonic cleaning to a second brush cleaning unit; in the second brush cleaning unit, rotating the wafer and performing a second brush cleaning with deionized water and ammonia water by a fixed cleaning brush.

[0007] In a possible implementation, the megasonic cleaning and the second brush cleaning of the wafer after the first brush cleaning while the wafer is rotating includes: transferring the wafer after the first brush cleaning to a second brush cleaning unit; in the second brush cleaning unit, rotating the wafer, and performing a second brush cleaning with deionized water and ammonia water by a fixed cleaning brush; transferring the wafer after the megasonic cleaning to the megasonic cleaning unit; in the megasonic cleaning unit, rotating the wafer, and performing megasonic cleaning on the wafer surface with a mixture of ammonia water, hydrogen peroxide and deionized water.

[0008] In a possible implementation, before the wafer is cleaned and dried by deionized water, nitrogen blowing, and spraying isopropyl alcohol while the wafer is rotating, it also includes: in a spin-drying unit, while the wafer is rotating, first cleaning it with a mixture of ammonia and deionized water, and then cleaning it with deionized water.

[0009] In a possible implementation, the time range for cleaning with the mixed solution is 8 to 10 seconds; and the time range for cleaning with the deionized water is 5 to 8 seconds.

[0010] In a possible implementation, while the wafer is rotating, the wafer is cleaned and dried by deionized water, nitrogen blowing, and spraying isopropyl alcohol, including: while the wafer is rotating, first spraying deionized water on the wafer surface for cleaning; while the wafer is rotating, using nitrogen to blow dry the deionized water sprayed on the wafer surface; while the wafer is rotating, spraying isopropyl alcohol on the wafer surface and achieving drying by rotation.

[0011] In a possible implementation, the first brushing time ranges from 60 to 65 seconds.

[0012] In a possible implementation, the megasonic cleaning time ranges from 50 to 55 seconds.

[0013] In a possible implementation manner, the direction of the rotation includes rotating in a horizontal direction or rotating in a vertical direction.

[0014] In a possible implementation, the size of the wafer includes 8 inches or 12 inches.

[0015] The present invention provides an enhanced cleaning method for large-size wafers. The present invention directly enters the cleaning brush unit 1, that is, first uses a brush to clean and then uses a hydrofluoric acid and deionized water mixture to clean, and performs rough cleaning under a strong acid state to wash away most of the grinding liquid residues on the wafer surface. When the wafer just leaves the grinding area, the grinding liquid and other chemical residues on the wafer surface can be brushed with a brush more quickly at the first time, and the effect of hydrofluoric acid improves the cleaning effect of the rough cleaning. The present invention improves the speed of removing the grinding liquid residues on the wafer surface, reduces the further etching of the wafer surface by the residues, and reduces the problem of inconsistent etching amount. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] Figure 1 is a schematic structural diagram of a cleaning system provided by an embodiment of the present invention;

[0018] Figure 2 is a flow chart of an implementation of a large-size wafer enhanced cleaning method provided by an embodiment of the present invention;

[0019] Figure 3 It is a schematic diagram of the structure of the scrubbing unit provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to enable people in the technical field to better understand the present solution, the technical solution in the embodiment of the present solution will be clearly described below in conjunction with the drawings in the embodiment of the present solution. Obviously, the described embodiment is an embodiment of a part of the present solution, not all of the embodiments. Based on the embodiments in the present solution, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present solution.

[0021] The term "including" and any other variations in the specification and claims of this solution and the above-mentioned drawings mean "including but not limited to", and are intended to cover non-exclusive inclusions and are not limited to the examples listed in the text. In addition, the terms "first" and "second" are used to distinguish different objects, rather than to describe a specific order. The following is a detailed description of the implementation of the present invention in conjunction with specific drawings:

[0022] First, the cleaning system and cleaning method of the current 300mm large-size wafer CMP process are explained.

[0023] Figure 1 Schematic diagram of the cleaning system provided by the embodiment of the present invention. Figure 1 A cleaning system includes a cleaning device and a front-end chemical cleaning device connected in sequence, that is, a chemical (ammonia water, hydrogen peroxide, etc.) ultrasonic cleaning device, a scrubbing device 1 and a scrubbing device 2, and a subsequent drying device, and a functional ultrapure water aeration generating device is also provided.

[0024] The cleaning method includes: using chemicals to ultrasonically clean the chemical residues on the surface of the CMP process wafer, using a brush to mechanically scrub the cleaned wafer, and drying the cleaned and scrubbed wafer.

[0025] The current fixed cleaning equipment and single cleaning method cannot meet the requirements of different processes and the increasingly high product yield requirements. Usually, the residue on the wafer surface cannot be cleaned cleanly. Due to the large size, the wafer surface cannot be dried in the drying unit, resulting in defects such as water spots, which has a great impact on the product yield.

[0026] Generally speaking, the cleaning method after chemical mechanical polishing is divided into the following steps: After the wafer is polished, it enters the cleaning area, the wafer enters the megasonic cleaning unit, and is horizontally rotated for cleaning. The surface is sprayed with a mixture of ammonia and hydrogen peroxide for ultrasonic cleaning. The wafer enters the cleaning brush unit 1, and the wafer is clamped up and down with a brush and rotated, and cleaned with a mixture of deionized water and hydrofluoric acid. The wafer enters the cleaning unit 2, and the wafer is clamped up and down with a brush and rotated, and cleaned with a mixture of deionized water and ammonia. The wafer enters the spin-drying unit, is cleaned with deionized water, and is spin-dried with nitrogen and high-speed spin-drying action. After the spin-drying is completed, the wafer is transferred back to the wafer box. The specific steps are as follows:

[0027] Step 1: The 300mm oxide wafer enters the grinding area for grinding, and after completion enters the flat-in-flat-out cleaning area.

[0028] Step 2: The wafer enters the megasonic cleaning unit. At this time, the wafer is rotated horizontally and the surface of the wafer is cleaned with a mixture of ammonia, hydrogen peroxide and deionized water for about 60 seconds.

[0029] Step 3: The wafer enters the cleaning unit 1, where it is clamped by four rotating shafts and rotated horizontally. At the same time, the cleaning brush clamps the wafer and releases it after brushing. During this period, it is cleaned with deionized water and hydrofluoric acid. The cleaning time is about 60 to 65 seconds.

[0030] Step 4: The wafer enters the cleaning unit 2, where it is clamped by four shafts and rotated horizontally. At the same time, the cleaning brush clamps the wafer and cleans it, then releases it. During this period, it is cleaned with deionized water and ammonia water for about 60 to 65 seconds.

[0031] Step 5: The wafer enters the drying unit, where it is clamped and rotated horizontally at high speed. At the same time, it is cleaned with deionized water, dried with nitrogen, and then sprayed with IPA. The wafer is then dried at high speed for about 65 to 70 seconds.

[0032] Step 6: After drying, the wafer is returned to the wafer box.

[0033] The embodiment of the present invention solves the problem of low cleaning efficiency and inconsistent etching amount caused by the existing method by directly performing brushing first.

[0034] Figure 2 This is a flowchart of the implementation of the large-size wafer enhanced cleaning method provided by the embodiment of the present invention. Figure 2 The present invention provides a large-size wafer enhanced cleaning method, which is applied to a cleaning system, wherein the cleaning system comprises a first scrubbing unit, a megasonic cleaning unit, a second scrubbing unit and a drying unit; the cleaning method comprises:

[0035] Step 201, transferring the ground large-size wafer to a first scrubbing unit.

[0036] Exemplarily, the size of the wafer includes 8 inches or 12 inches. For example, the method of the embodiment of the present invention is applicable to an 8-inch / 12-inch CMP machine.

[0037] Exemplarily, the method of the embodiment of the present invention is applicable to various CMP process requirements, such as copper (Cu), oxide (Oxide), tungsten (Tungsten), shallow trench isolation (STI) and Poly.

[0038] In some embodiments, before step 201, the process further includes: the wafer enters the grinding area for grinding. For example, a 300 mm oxide wafer enters the grinding area for grinding, and then enters the flat-in-flat-out cleaning area after grinding.

[0039] Step 202: In a first scrubbing unit, the wafer is rotated and first scrubbing is performed using a fixed cleaning brush with deionized water and hydrofluoric acid.

[0040] Figure 3 Schematic diagram of the structure of the scrubbing unit provided by the embodiment of the present invention. Figure 3 Wafer cleaning usually uses a brush to clamp the wafer and rotate it mechanically. At the same time, the wafer is also rotated by rollers, and the cleaning fluid is sprayed to clean the metal ions and other residues on the wafer surface.

[0041] Exemplarily, the first brushing time ranges from 60 to 65 seconds.

[0042] Exemplarily, the megasonic cleaning time ranges from 50 to 55 seconds.

[0043] In some embodiments, the wafer is clamped by four rotating shafts and rotated horizontally, while a cleaning brush clamps the wafer and releases it after brushing. During the cleaning process, it is cleaned with deionized water and hydrofluoric acid, and the cleaning time is about 60 to 65 seconds.

[0044] Step 203 , while the wafer is rotating, performing megasonic cleaning and a second scrubbing on the wafer after the first scrubbing.

[0045] In some embodiments, megasonic cleaning and a second brushing are further performed after the first brushing. In an exemplary embodiment, megasonic cleaning is performed first, followed by the second brushing. In another exemplary embodiment, the second brushing is performed first, followed by the megasonic cleaning.

[0046] Step 204, in the spin-drying unit, while the wafer is rotating, the wafer is cleaned and dried by blowing with deionized water and nitrogen and spraying with isopropyl alcohol to complete the cleaning of the large-size wafer.

[0047] In a possible implementation, while the wafer is rotating, the wafer is cleaned and dried by deionized water, nitrogen blowing, and spraying isopropyl alcohol, including: while the wafer is rotating, first spraying deionized water on the wafer surface for cleaning; while the wafer is rotating, using nitrogen to blow dry the deionized water sprayed on the wafer surface; while the wafer is rotating, spraying isopropyl alcohol on the wafer surface and achieving drying by rotation.

[0048] The present invention directly enters the cleaning brush unit 1, that is, first uses a brush to clean and then uses a hydrofluoric acid deionized water mixture to clean, and performs rough cleaning under a strong acid state to wash away most of the grinding liquid residues on the wafer surface. As soon as the wafer leaves the grinding area, the grinding liquid and other chemical residues on the wafer surface can be brushed more quickly at the first time, and the effect of hydrofluoric acid improves the cleaning effect of the rough cleaning. The present invention improves the speed of removing the grinding liquid residues on the wafer surface, reduces the further etching of the wafer surface by the residues, and reduces the problem of inconsistent etching amount.

[0049] The first implementation method of step 203 is described below.

[0050] In a possible implementation, while the wafer is rotating, performing megasonic cleaning and a second brush cleaning on the wafer after the first brush cleaning includes: transferring the wafer after the first brush cleaning to a megasonic cleaning unit; in the megasonic cleaning unit, rotating the wafer, and performing megasonic cleaning on the wafer surface with a mixture of ammonia water, hydrogen peroxide and deionized water; transferring the wafer after the megasonic cleaning to a second brush cleaning unit; in the second brush cleaning unit, rotating the wafer, and performing a second brush cleaning with deionized water and ammonia water by a fixed cleaning brush.

[0051] In some embodiments, the wafer enters the megasonic cleaning unit, where the wafer is horizontally rotated and the surface of the wafer is cleaned with a mixture of ammonia, hydrogen peroxide and deionized water for about 60 seconds. The wafer enters the second scrubbing unit, where the wafer is clamped by four rotating shafts and rotated horizontally, while the cleaning brush clamps the wafer and releases it after scrubbing, and deionized water and ammonia are used for cleaning, and the cleaning time is about 60 to 65 seconds.

[0052] The following is a comprehensive embodiment to illustrate the method of performing a first scrubbing, a prior acoustic cleaning and then a second scrubbing.

[0053] Step 1: The 300mm oxide wafer enters the grinding area for grinding, and after completion enters the flat-in-flat-out cleaning area.

[0054] Step 2: The wafer enters the first scrubbing unit, where it is clamped by four rotating shafts and rotated horizontally. At the same time, the cleaning brush clamps the wafer and releases it after scrubbing. During this period, it is cleaned with deionized water and hydrofluoric acid. The cleaning time is about 60 to 65 seconds.

[0055] Step 3: The wafer enters the megasonic cleaning unit. At this time, the wafer is rotated horizontally and the surface of the wafer is cleaned with a mixture of ammonia, hydrogen peroxide and deionized water for about 60 seconds.

[0056] Step 4: The wafer enters the second scrubbing unit. The wafer is clamped by four rotating shafts and rotated horizontally. At the same time, the cleaning brush clamps the wafer and releases it after scrubbing. During the cleaning process, it is cleaned with deionized water and ammonia water. The cleaning time is about 60 to 65 seconds.

[0057] Step 5: The wafer enters the drying unit, where it is clamped and rotated horizontally at high speed. It is then washed with deionized water, dried with nitrogen, and then sprayed with IPA. The drying process is then combined with a high-speed drying process. The time is about 65 to 70 seconds.

[0058] Step 6: After drying, the wafer is returned to the wafer box.

[0059] The above improved cleaning method after CMP grinding of the present invention directly enters the first scrubbing unit first, that is, first scrubbing with a brush and cleaning with a mixture of hydrofluoric acid and deionized water, and rough cleaning is performed under strong acid conditions to wash away most of the grinding liquid residues on the surface of the wafer. Then enter the megasonic unit to perform ultrasonic cleaning with a mixture of ammonia, hydrogen peroxide and deionized water to perform detailed cleaning of the oxidized residues on the surface of the wafer. Then enter the second scrubbing unit, scrub with a brush and a mixture of ammonia and deionized water to clean the chemical residues on the weak acid surface again, and finally enter the drying unit for drying.

[0060] Function 1: As soon as the wafer leaves the grinding area, the grinding fluid and other chemical residues on the surface of the wafer can be scrubbed away more quickly and immediately, and the effect of hydrofluoric acid can enhance the cleaning effect of rough cleaning.

[0061] Function 2: Enter the megasonic unit for ultrasonic cleaning. The mixture of ammonia, hydrogen peroxide and deionized water can effectively and finely clean the organic oxide residues on the surface of the wafer.

[0062] Then the cleaning brush unit uses a mixture of ammonia and deionized water to perform a more detailed cleaning of other chemical residues on the surface of the wafer; this more effectively improves the cleaning effect.

[0063] A second implementation of step 203 is described below.

[0064] In a possible implementation, while the wafer is rotating, performing megasonic cleaning and a second brush cleaning on the wafer after the first brush cleaning includes: transferring the wafer after the first brush cleaning to a second brush cleaning unit; in the second brush cleaning unit, rotating the wafer, and performing a second brush cleaning with deionized water and ammonia water through a fixed cleaning brush; transferring the wafer after the megasonic cleaning to the megasonic cleaning unit; in the megasonic cleaning unit, rotating the wafer, and performing megasonic cleaning on the wafer surface with a mixture of ammonia water, hydrogen peroxide and deionized water.

[0065] In some embodiments, the wafer enters the second scrubbing unit, where the wafer is clamped by four rotating shafts and rotated horizontally. At the same time, the cleaning brush clamps the wafer and releases it after scrubbing. During the cleaning process, it is cleaned with deionized water and ammonia water. The cleaning time is about 60 to 65 seconds. The wafer enters the megasonic cleaning unit. At this time, the wafer is rotated horizontally and the surface of the wafer is cleaned with a mixture of ammonia, hydrogen peroxide and deionized water (if it is a tungsten process, only a mixture of ammonia and deionized water is used). The time is about 50 to 55 seconds.

[0066] The following is a comprehensive example to illustrate the method of first brushing, then second brushing and then megasonic cleaning.

[0067] Step 1: The 300mm oxide wafer enters the grinding area for grinding, and after completion enters the flat-in-flat-out cleaning area.

[0068] Step 2: The wafer enters the first brush cleaning unit. The wafer is clamped by four rotating shafts and rotated horizontally. At the same time, the cleaning brush clamps the wafer and releases it after brushing. During the cleaning process, it is cleaned with deionized water and hydrofluoric acid. The cleaning time is about 60 to 65 seconds.

[0069] Step 3: The wafer enters the second brush cleaning unit. The wafer is clamped by four rotating shafts and rotated horizontally. At the same time, the cleaning brush clamps the wafer and releases it after brushing. During the cleaning process, it is cleaned with deionized water and ammonia water. The cleaning time is about 60 to 65 seconds.

[0070] Step 4: The wafer enters the megasonic cleaning unit. At this time, the wafer is rotated horizontally and the surface of the wafer is cleaned with a mixture of ammonia, hydrogen peroxide and deionized water (if it is a tungsten process, only a mixture of ammonia and deionized water is used). The time is about 50 to 55 seconds.

[0071] Step 5: The wafer enters the spin-drying unit, where it is clamped and rotated horizontally at high speed. At the same time, it is cleaned with a mixture of ammonia and deionized water for about 8 to 10 seconds, and then cleaned with deionized water for about 5 to 8 seconds.

[0072] Step 5: The wafer is further dried in the drying unit. After being cleaned with deionized water, it is blown dry with nitrogen. Finally, IPA is sprayed on the surface of the wafer, and the wafer is dried with high-speed drying. The total time is also about 65 to 70 seconds.

[0073] Step 6: After drying, the wafer is returned to the wafer box.

[0074] Under certain process requirements, different metal layers on the wafer surface require different cleaning methods.

[0075] The embodiment of the present invention first directly enters the first brushing unit and the second brushing unit, that is, it is first brushed with a brush and assisted by a hydrofluoric acid deionized water mixture cleaning, and ammonia and deionized water mixture cleaning, and then enters the megasonic unit for ultrasonic cleaning with ammonia, hydrogen peroxide and deionized water mixture, and finally enters the spin-drying unit for a short time of ammonia and deionized water final cleaning, and finally spin-dried.

[0076] Function 1: As soon as the wafer leaves the grinding area, the grinding fluid and other chemical residues on the surface of the wafer can be cleaned more quickly by two-step brushes, and the effects of hydrofluoric acid and ammonia water can enhance the cleaning effect of rough cleaning.

[0077] Function 2: After two steps of brushing, the wafer enters the megasonic unit for ultrasonic cleaning. The mixture of ammonia, hydrogen peroxide and deionized water can effectively clean the surface of the oxide wafer in a fine manner, that is, some special particles and oxide residues.

[0078] The final cleaning step in the spin-drying unit is to clean special metal layers or surface particles with strong adhesion, assisted by nitrogen blowing and deionized water spraying for the final cleaning. This can more effectively remove more difficult-to-clean residues and effectively improve the product yield.

[0079] The following examples illustrate the ammonia cleaning in the spin-drying unit.

[0080] In a possible implementation, before the wafer is cleaned and dried by deionized water, nitrogen blowing, and spraying isopropyl alcohol while the wafer is rotating, it also includes: in a spin-drying unit, while the wafer is rotating, first cleaning it with a mixture of ammonia and deionized water, and then cleaning it with deionized water.

[0081] Exemplarily, the time range for cleaning with the mixed solution is 8 to 10 seconds; the time range for cleaning with deionized water is 5 to 8 seconds.

[0082] In a possible implementation, the direction of rotation includes rotating in a horizontal direction or rotating in a vertical direction.

[0083] The present invention provides a variety of cleaning methods after chemical mechanical polishing. The main method is to add a cleaning step in the multi-step cleaning after wafer polishing, and to improve the cleaning method or different cleaning steps in the single-step cleaning, so as to clean the polishing liquid and chemical residues on the wafer surface.

[0084] The post-CMP cleaning method provided by the embodiment of the present invention can effectively clean chemical residues and other defects in the CMP process, which helps to improve the yield of products and also helps to improve WPH (wafer per hour), that is, improve the cleaning efficiency of wafers.

[0085] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A large-size wafer enhanced cleaning method, characterized in that: Applied to a cleaning system, the cleaning system comprises a first scrubbing unit, a megasonic cleaning unit, a second scrubbing unit and a drying unit; the cleaning method comprises: Transferring the ground large-size wafer to the first scrubbing unit; In the first scrubbing unit, the wafer is rotated and scrubbed for the first time using a fixed cleaning brush with deionized water and hydrofluoric acid; Under the wafer rotation state, performing megasonic cleaning and second brush cleaning on the wafer after the first brush cleaning; In the spin-drying unit, while the wafer is rotating, it is cleaned and dried by blowing with deionized water, nitrogen, and spraying with isopropyl alcohol to complete the cleaning of large-size wafers.

2. The large-size wafer enhanced cleaning method according to claim 1, characterized in that: The method of performing megasonic cleaning and second scrubbing on the wafer after the first scrubbing while the wafer is rotating comprises: transferring the wafer after the first scrubbing to a megasonic cleaning unit; In the megasonic cleaning unit, the wafer is rotated and the surface of the wafer is megasonic cleaned with a mixture of ammonia, hydrogen peroxide and deionized water; transferring the wafer after megasonic cleaning to a second scrubbing unit; In the second scrubbing unit, the wafer is rotated and scrubbed for the second time using a fixed cleaning brush with deionized water and ammonia water.

3. The large-size wafer enhanced cleaning method according to claim 1, characterized in that: The method of performing megasonic cleaning and second scrubbing on the wafer after the first scrubbing while the wafer is rotating comprises: transferring the wafer after the first scrubbing to the second scrubbing unit; In the second scrubbing unit, the wafer is rotated and scrubbed for a second time using a fixed cleaning brush with deionized water and ammonia water; transferring the wafer after megasonic cleaning to a megasonic cleaning unit; In the megasonic cleaning unit, the wafer is rotated and the surface of the wafer is megasonic cleaned with a mixture of ammonia, hydrogen peroxide and deionized water.

4. The large-size wafer enhanced cleaning method according to claim 1, characterized in that: While the wafer is spinning, the wafer is cleaned and dried by blowing with deionized water, nitrogen, and spraying with isopropyl alcohol. The following steps are also included: In the spin-drying unit, while the wafer is rotating, it is first cleaned with a mixture of ammonia and deionized water and then cleaned with deionized water.

5. The large-size wafer enhanced cleaning method according to claim 4, characterized in that: The time range for the mixed solution to clean is 8 to 10 seconds; The deionized water cleaning time ranges from 5 to 8 seconds.

6. The large-size wafer enhanced cleaning method according to claim 1, characterized in that: The cleaning and drying of the wafer by blowing with deionized water, nitrogen and spraying with isopropyl alcohol while the wafer is rotating includes: While the wafer is rotating, first spray deionized water on the wafer surface for cleaning; While the wafer is rotating, the deionized water sprayed on the surface of the wafer is blown dry with nitrogen gas; While the wafer is rotating, isopropyl alcohol is sprayed on the wafer surface and dried by rotation.

7. The large-size wafer enhanced cleaning method according to claim 1, characterized in that: The first brushing time ranges from 60 to 65 seconds.

8. The large-size wafer enhanced cleaning method according to claim 1, characterized in that: The megasonic cleaning time ranges from 50 to 55 seconds.

9. The large-size wafer enhanced cleaning method according to claim 1, characterized in that: The direction of the rotation includes rotating in a horizontal direction or rotating in a vertical direction.

10. The large-size wafer enhanced cleaning method according to claim 1, characterized in that: The size of the wafer includes 8 inches or 12 inches.

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