Wafer cleaning device and wafer cleaning method

Abstract

According to the wafer cleaning device and the wafer cleaning method provided by the invention, the wafer with an oxide layer on the back surface is cleaned by adopting a mode of combining the cleaning tanks and the cleaning table, and the vertically placed wafer is cleaned by adopting different cleaning liquids which do not corrode the back surface of the wafer in different cleaning tanks; according to the technical scheme, hydrofluoric acid with high cleaning capacity is used for cleaning the horizontally placed wafer in the cleaning table, and the wafer is horizontally placed in the cleaning table, so that an oxide layer on the back surface of the wafer cannot be corroded by the hydrofluoric acid. Cleaning is carried out in the mode that the cleaning tanks and the cleaning table are combined, and cleaning liquid in the different cleaning tanks is reasonably selected, so that particles on the surface of a final wafer are greatly reduced.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor processing technology, and in particular to a wafer cleaning device and a wafer cleaning method. Background Art

[0002] Silicon-On-Insulator (SOI) is a semiconductor manufacturing technology. Figure 1 As shown, an SOI wafer generally includes a substrate silicon 10, a top silicon layer 30, and a buried oxide layer 20. The substrate silicon 10 and the top silicon 30 are separated by the buried oxide layer 20, and an oxide layer 40 is formed on the back of the substrate silicon 10. SOI wafers are generally formed using a bonding process. After bonding two silicon wafers together, the bonded wafers often need to undergo reinforcement heat treatment, chamfering, etching, grinding, fine cleaning, CMP polishing, etc. to obtain an SOI wafer. During this system operation, the oxide layer 40 on the back of the substrate silicon 10 protects the back of the substrate silicon 10. The CMP polishing process will produce highly adhesive particles, organic residues, and polishing liquid residues, which need to be removed by cleaning.

[0003] After the SOI wafer is cleaned using the existing conventional cleaning process, a large amount of particles still remain on the wafer surface. Summary of the Invention

[0004] The object of the present invention is to provide a wafer cleaning device and a wafer cleaning method to solve the defect that a large amount of particles still remain on the surface of the SOI wafer after the SOI wafer is cleaned using the existing conventional cleaning process.

[0005] In order to solve the above problems, the present invention provides a wafer cleaning device, which includes: a first cleaning space, a flip structure and a second cleaning space;

[0006] The first cleaning space includes a plurality of cleaning tanks, wherein different or partially identical cleaning liquids are provided in the plurality of cleaning tanks to clean the front and back sides of the wafer;

[0007] The second cleaning space includes at least one cleaning station, in which a cleaning liquid is provided to clean the front side of the wafer;

[0008] The flip structure is used to adjust the direction of the wafer to a vertical direction and transfer it to each of the cleaning tanks, and is used to adjust the direction of the wafer to a horizontal direction and transfer it to the cleaning platform.

[0009] Optionally, in the wafer cleaning device, the first cleaning space further includes a drying processing unit, and the drying processing unit is used to dry the wafers after being cleaned in the cleaning tank.

[0010] Optionally, in the wafer cleaning device, the wafer cleaning device further includes a rinsing tank, the rinsing tank is arranged between two adjacent cleaning tanks, and the cleaning liquid in the rinsing tank is deionized water.

[0011] Optionally, in the wafer cleaning device, the flipping structure includes a first robotic arm, a second robotic arm and a third robotic arm, the first robotic arm is used to place the wafer vertically in the cleaning tank, the second robotic arm is used to take the wafer out of the cleaning tank and place the wafer horizontally in a waiting position, and the third robotic arm is used to transfer the wafer located in the waiting position to the cleaning table.

[0012] The present invention also provides a wafer cleaning method, which is performed using the wafer cleaning device as described in any of the preceding items. The wafer cleaning method comprises:

[0013] Performing a first cleaning process, using the flip structure to vertically place the target wafer into the first cleaning space and sequentially clean it through multiple cleaning tanks; and

[0014] A second cleaning process is performed, whereby the target wafer is flipped to a horizontal position using the flip structure and transferred to the cleaning station for cleaning.

[0015] Optionally, in the wafer cleaning method, the plurality of cleaning tanks include a first cleaning tank, a second cleaning tank, and a third cleaning tank, the first cleaning tank is used to provide ozone water for cleaning, the second cleaning tank is used to provide a mixture of liquid ammonia, hydrogen peroxide, and water for cleaning, and the third cleaning tank is used to provide a mixture of hydrochloric acid and hydrogen peroxide for cleaning;

[0016] When the first cleaning process is performed, the target wafer is cleaned in the first cleaning tank, the second cleaning tank and the third cleaning tank in sequence.

[0017] Optionally, in the wafer cleaning method, the process parameters for cleaning in the second cleaning tank are set as follows: a cleaning temperature of 35 to 70° C., a mass concentration ratio of liquid ammonia to hydrogen peroxide in the mixed liquid of 1:2 to 0.3:3.5, a mixed liquid flow rate of 20 to 30 L / min, an ultrasonic megasonic power of 800 to 1200 W, and a cleaning time of 220 to 300 s;

[0018] The process parameters for cleaning in the first cleaning tank and the third cleaning tank are set as follows: the cleaning temperature is room temperature, the flow rate is 20-28 L / min, the ultrasonic megasonic power is 1500-2000 W, the cleaning time is 180-300 s, the ozone water concentration in the first cleaning tank is 25-30 ppm, and the mass concentration ratio of hydrochloric acid to hydrogen peroxide in the third cleaning tank is 1:1-1:2.

[0019] Optionally, in the wafer cleaning method, when performing the first cleaning process, after the target wafer is cleaned using the cleaning tank, the target wafer is dried.

[0020] Optionally, in the wafer cleaning method, when performing the first cleaning process, the target wafer after being cleaned in each cleaning tank is also rinsed, and the cleaning liquid is deionized water.

[0021] Optionally, in the wafer cleaning method, in the second cleaning process, the cleaning station uses a mixture of ozone water and hydrofluoric acid to clean the target wafer, and the cleaning is cyclically performed at least twice.

[0022] In summary, the wafer cleaning device and wafer cleaning method provided by the present invention adopts a combination of a cleaning tank and a cleaning table to clean a wafer with an oxide layer on the back, adopts different cleaning solutions that do not corrode the back of the wafer in different cleaning tanks to clean the vertically placed wafer, and uses hydrofluoric acid with a strong cleaning ability in the cleaning table to clean the horizontally placed wafer. Since the wafer is placed horizontally in the cleaning table, the oxide layer on the back of the wafer will not be corroded by hydrofluoric acid. Cleaning is performed by combining a cleaning tank and a cleaning table, and the cleaning solutions of different cleaning tanks are reasonably selected, so that the particles on the surface of the final wafer are greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the structure of SOI wafer;

[0024] Figure 2 A schematic structural diagram of a wafer cleaning device provided in an embodiment of the present invention;

[0025] Figure 3 A schematic diagram of cleaning in a cleaning tank;

[0026] Figure 4 A schematic diagram of cleaning on a cleaning platform;

[0027] Figure 5 A flowchart of a wafer cleaning method provided by an embodiment of the present invention;

[0028] Figure 6 Schematic diagram of particle detection in four comparative examples according to an embodiment of the present invention;

[0029] The descriptions of the reference numerals are as follows:

[0030] 10-substrate silicon; 20-buried oxide layer; 30-top silicon; 40-oxide layer;

[0031] 100-first cleaning space; 200-turnover structure; 300-second cleaning space;

[0032] 100a-cleaning tank; 300a-cleaning table;

[0033] 101-first cleaning tank; 102-second cleaning tank; 103-third cleaning tank; 104-fourth cleaning tank; 105-drying processing unit;

[0034] 201-first robotic arm; 202-second robotic arm; 203-third robotic arm;

[0035] 400-wafer loading unit. DETAILED DESCRIPTION

[0036] The wafer cleaning apparatus and method proposed in the present invention will be further described in detail below, with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are highly simplified and not to exact scale, and are intended solely to facilitate the purpose of illustrating the embodiments of the present invention. Furthermore, the structures depicted in the drawings are often portions of actual structures. In particular, different drawings may require different emphases and may use different scales. It should be understood that relative terms such as "above," "below," "top," and "bottom" in the drawings may be used to describe the relationships of various elements to one another. These relative terms are intended to encompass different orientations of elements other than those depicted in the drawings. For example, if the device is inverted relative to the view in the drawings, an element described as "above" another element would now be below that element. It should also be understood that, unless otherwise specified or indicated, terms such as "first," "second," and "third" in this specification are used solely to distinguish between components, elements, steps, and the like, and are not intended to indicate logical or sequential relationships between components, elements, steps, or the like.

[0037] An embodiment of the present invention provides a wafer cleaning device, which is mainly used to clean wafers with an oxide layer on the back side, but is also applicable to wafers without an oxide layer on the back side.

[0038] See Figure 2 Combined with Figure 3 and Figure 4The wafer cleaning apparatus provided in an embodiment of the present invention includes: a first cleaning space 100, a flip structure 200, and a second cleaning space 300; the first cleaning space 100 includes a plurality of cleaning tanks 100a, each of which contains different or partially identical cleaning liquids to clean the front and back surfaces of the wafer; the second cleaning space 300 includes at least one cleaning station 300a, that is, the number of the cleaning stations 300a can be one or more; the flip structure 200 is used to adjust the orientation of the wafer to a vertical direction and transfer it to each of the cleaning tanks 100a, and to adjust the orientation of the wafer to a horizontal direction and transfer it to the cleaning station 300a. It can be understood that a horizontal orientation of the wafer means that the wafer surface extends in the horizontal direction, and a vertical orientation of the wafer means that the wafer surface extends in the vertical direction.

[0039] Please refer to Figure 2 The multiple cleaning tanks 100a include a first cleaning tank 101, a second cleaning tank 102 and a third cleaning tank 103. The first cleaning tank 101 is used to provide ozone water for cleaning, the second cleaning tank 102 is used to provide a mixture of liquid ammonia, hydrogen peroxide and water for cleaning, and the third cleaning tank 103 is used to provide a mixture of hydrochloric acid and hydrogen peroxide for cleaning; the cleaning station 300a is used to provide a mixture of ozone water and hydrofluoric acid for cleaning, and preferably, the cleaning station 300a is also used to provide nitrogen for cleaning after providing the mixture of ozone water and hydrofluoric acid for cleaning, so that the cleaned wafers are in a dry state.

[0040] In addition, preferably, the wafer cleaning device also includes a rinsing tank 104, which is arranged between two adjacent cleaning tanks 100a and is used to rinse the cleaning liquid on the wafer surface after the cleaning tank 100a cleans the wafer. The cleaning liquid can optionally be deionized water.

[0041] In each of the cleaning tanks 100a, the wafers are placed vertically, and the cleaning liquid can clean both the front and back sides of the wafers. In the cleaning station 300a, the wafers are placed horizontally, and the cleaning liquid cleans the front sides of the wafers. When using the cleaning tanks 100a for cleaning, the cleaning liquid selected is one that does not corrode the oxide layer on the back side of the wafer (hereinafter referred to as the back oxide layer). When using the cleaning station 300a for cleaning, although the cleaning liquid selected is a mixture of ozone water and hydrofluoric acid, because the wafers are placed horizontally, the cleaning liquid does not come into contact with the back side of the wafer during cleaning, thereby corroding the back oxide layer.

[0042] It should be noted here that when the wafer is placed horizontally, the back of the wafer is generally facing down. For example, for an SOI wafer, when placed horizontally, the substrate silicon is at the bottom and the top silicon is at the top, and the side of the substrate silicon away from the top silicon is the back of the wafer.

[0043] See accordingly. Figure 5 The embodiment of the present invention further provides a wafer cleaning method, which uses the wafer cleaning device provided in this embodiment for cleaning, and the wafer cleaning method includes the following steps:

[0044] S1, performing a first cleaning process, using the flip structure 200 to vertically place the target wafer into the first cleaning space and sequentially clean it through multiple cleaning tanks, that is, sequentially transferring the target wafer to the first cleaning tank 101, the second cleaning tank 102 and the third cleaning tank 103 for cleaning; and

[0045] S2 , performing a second cleaning process, using the flip structure 200 to flip the target wafer to a horizontal state and transferring it to the cleaning station 300 a for cleaning.

[0046] That is, the wafer cleaning device and wafer cleaning method provided in the embodiments of the present invention perform cleaning by combining a cleaning tank and a cleaning table, and rationally select the cleaning liquids of different cleaning tanks, so that the particles on the surface of the final wafer can be greatly reduced.

[0047] The cleaning purposes of the cleaning liquid in each cleaning tank 100a are as follows:

[0048] Cleaning in the first cleaning tank 101: Ozone water has strong oxidizing properties and can effectively remove organic matter and some metal pollutants on the wafer surface;

[0049] The second cleaning tank 102 is used for cleaning: it mainly removes organic matter and particles, and at the same time forms a thin silicon dioxide layer on the surface of the wafer, which helps to remove metal pollutants in subsequent steps.

[0050] Cleaning in the third cleaning tank 103: mainly removes metal contaminants introduced in the cleaning step of the second cleaning tank 102, and forms a protective passivation layer on the surface of the wafer.

[0051] Step S1 further includes: using the rinse tank 104 disposed between two adjacent cleaning tanks 100a to clean the target wafer after cleaning in each cleaning tank 100a, i.e., using deionized water for cleaning. After cleaning in the first cleaning tank 101, cleaning in the rinse tank 104 can remove ozone and other impurities remaining after cleaning with ozone water, ensuring the cleanliness of the wafer surface. After cleaning in the second cleaning tank 102, cleaning in the rinse tank 104 can remove residual chemicals.

[0052] The cleaning purpose of the cleaning liquid in the cleaning station 300a is as follows:

[0053] Cleaning with a mixture of hydrofluoric acid and ozone water: Hydrofluoric acid is used to remove the natural oxide layer and attached metal ions on the wafer surface, and ozone water is used to further remove organic pollutants and metal contamination on the wafer surface.

[0054] Nitrogen cleaning: Nitrogen cleaning has the advantages of being water-free, environmentally friendly and energy-saving. It removes impurities on the wafer surface through physical or chemical vapor deposition.

[0055] In this embodiment, preferably, the flipping structure 200 adopts a robotic arm. Specifically, the flipping structure 200 includes a first robotic arm 201, a second robotic arm 202 and a third robotic arm 203. The first robotic arm 201 is used to place the wafer vertically in the cleaning tank 100a, the second robotic arm 202 is used to take the wafer out of the cleaning tank 100a and place the wafer horizontally in a waiting position (not shown), and the third robotic arm 203 is used to transfer the wafer in the waiting position to the cleaning table 300a.

[0056] Since multiple wafers can be cleaned simultaneously in the cleaning tank 100a, while only a single wafer can be cleaned in the cleaning station, the coordination of the three robotic arms facilitates a smooth and efficient cleaning process.

[0057] The wafer cleaning device provided in this embodiment also includes a wafer loading unit 400. In order to avoid interference between the operations of each arm, the wafer cleaning device provided in this embodiment is designed to have the first cleaning space 100 and the second cleaning space 300 distributed on both sides of the flip structure 200, the first cleaning tank 101, the second cleaning tank 102, and the third cleaning tank 103 arranged in sequence according to the cleaning order, and the wafer loading unit 400 is located on the side of the first cleaning tank 101 away from the second cleaning tank 102.

[0058] Based on the above optimized arrangement, the first robot arm 201 can take the wafers from the wafer loading unit 400 and transfer them to each cleaning tank 100a for cleaning in sequence without moving back and forth repeatedly, thereby simplifying the cleaning process and improving cleaning efficiency.

[0059] Furthermore, in this embodiment, the first cleaning chamber 100 also includes a drying unit 105. A rinsing tank 104 is positioned between the third cleaning tank 103 and the drying unit 105. Specifically, after the wafers are cleaned in the third cleaning tank 103, they are rinsed with deionized water and dried before being transferred to the cleaning station 300a. This drying process ensures that no moisture remains on the wafer surface, preventing contamination during subsequent processing. Preferably, the waiting area is located near the drying unit 105.

[0060] In summary, on one side of the flip structure 200 (eg Figure 1 As shown in the left side, seven spaces can be designed to be arranged in sequence, and the first cleaning tank 101, the rinsing tank 104, the second cleaning tank 102, the rinsing tank 104, the third cleaning tank 103, the rinsing tank 104, and the drying processing unit 105 are arranged in the seven spaces respectively; on the other side of the flip structure 200 (as shown in the left side), the first cleaning tank 101, the rinsing tank 104, the second cleaning tank 102, the rinsing tank 104, the third cleaning tank 103, the rinsing tank 104, and the drying processing unit 105 are arranged in the seven spaces respectively. Figure 1 As shown on the right side, several spaces arranged in sequence can also be designed, and the cleaning station 300a is arranged in one space. The cleaning station 300a arranged in each space can use the same and / or different cleaning liquids to clean the target wafer in sequence.

[0061] The ability to remove particles from the wafer surface is mainly affected by the type of cleaning fluid, but the specific process parameter settings and the number of cleaning times will also affect the ability to remove particles from the wafer surface.

[0062] In this embodiment, preferably, in the second cleaning process, the cleaning station 300a is cleaned with a mixture of ozone water and hydrofluoric acid for at least two cycles, and then cleaned with nitrogen.

[0063] In addition, preferably, the process parameters for cleaning in the second cleaning tank 102 are set as follows: the cleaning temperature is 35-70°C, the mass concentration ratio of liquid ammonia to hydrogen peroxide in the mixed liquid is 1:2-0.3:3.5, the mixed liquid flow rate is 20-30 L / min, the ultrasonic megasonic power is 800-1200 W, and the cleaning time is 220-300 s; the process parameters for cleaning in the first cleaning tank 101 and the third cleaning tank 103 are set as follows: the cleaning temperature is room temperature, the flow rate is 20-28 L / min, the ultrasonic megasonic power is 1500-2000 W, the cleaning time is 180-300 s, the ozone water concentration in the first cleaning tank 101 is 25-30 ppm; the mass concentration ratio of hydrochloric acid to hydrogen peroxide in the third cleaning tank 103 is 1:1-1:2.

[0064] The effects achieved by the wafer cleaning apparatus and wafer cleaning method provided by this embodiment are further illustrated below with reference to several comparative examples. In the comparative examples below, an SOI wafer containing a back oxygen layer is used as a target wafer. After undergoing a reinforcement heat treatment, chamfering, etching, grinding, rough cleaning, and polishing, the SOI wafer is cleaned in different ways.

[0065] [Comparative Example 1]

[0066] The SOI wafer is cleaned in the first cleaning tank + rinse tank + second cleaning tank + rinse tank + third cleaning tank.

[0067] Among them, the cleaning conditions of the first cleaning tank are: temperature of 70°C, mass concentration ratio of liquid ammonia to hydrogen peroxide of 1:2, mixed liquid flow rate of 25L / min, ultrasonic megasonic power of 1000W, and cleaning time of 300s.

[0068] Except for the first cleaning tank, all other cleaning tanks were operated at room temperature, with a flow rate of 28 L / min, an ultrasonic megasonic power of 2000 W, and a duration of 180 seconds. Furthermore, the ozone water concentration during cleaning was 30 ppm, and the mass ratio of hydrochloric acid to hydrogen peroxide during cleaning in the second cleaning tank was 0.5:0.5.

[0069] [Comparative Example 2]

[0070] Two cycles of cleaning are performed using a cleaning station.

[0071] The cleaning conditions are as follows: the mixed liquid temperature is 25°C, the hydrofluoric acid concentration is 6000 ppm, the hydrofluoric acid flow rate is 1.8 L / min, the ozone water concentration is 30 ppm, and the ozone water flow rate is 1.8 L / min.

[0072] [Comparative Example 3]

[0073] Two cycles of cleaning were performed according to the cleaning method of Comparative Example 1.

[0074] The cleaning conditions for various cleanings were the same as those in Comparative Example 1.

[0075] [Comparative Example 4]

[0076] The SOI wafer was first cleaned according to the cleaning method of Comparative Example 1 and then cleaned according to the cleaning method of Comparative Example 2. The cleaning conditions of the former were the same as those of Comparative Examples 1 and 3, and the cleaning conditions of the latter were the same as those of Comparative Example 2.

[0077] The number of particles on the wafer surfaces cleaned by the above four comparative examples was counted, and the statistical structure is shown in Table 1:

[0078] Table 1

[0079]

[0080]

[0081] From Table 1 and combined Figure 3 It can be seen that by using the wafer cleaning device and wafer cleaning method provided in this embodiment, the particles on the wafer surface can be greatly reduced.

[0082] In the above four comparative examples, the cleaning of SOI wafers is used as an example, but it should be understood that the wafer cleaning device and wafer cleaning method provided in this embodiment are not only applicable to the cleaning of SOI wafers, but also applicable to the cleaning of other wafers with a back oxygen layer, and even applicable to the cleaning of wafers without a back oxygen layer.

[0083] In summary, the wafer cleaning device and wafer cleaning method provided by the embodiment of the present invention adopts a combination of a cleaning tank and a cleaning table to clean a wafer with an oxide layer on the back side, adopts different cleaning solutions that do not corrode the back side of the wafer in different cleaning tanks to clean the vertically placed wafer, and utilizes hydrofluoric acid with a strong cleaning ability to clean the horizontally placed wafer in the cleaning table. Since the wafer is placed horizontally in the cleaning table, the oxide layer on the back side of the wafer will not be corroded by hydrofluoric acid. Cleaning is performed by combining a cleaning tank and a cleaning table, and the cleaning solutions of different cleaning tanks are reasonably selected, so that the particles on the final wafer surface are greatly reduced.

[0084] It should be noted that although the present invention has been disclosed above with reference to preferred embodiments, any person skilled in the art can utilize the above-disclosed technical content to make many possible changes and modifications to the technical solution of the present invention, or modify it into equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments in accordance with the technical essence of the present invention that do not depart from the content of the technical solution of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A wafer cleaning device, characterized in that: The wafer cleaning device comprises: a first cleaning space, a flip structure, and a second cleaning space; The first cleaning space includes a plurality of cleaning tanks, wherein different or partially identical cleaning liquids are provided in the plurality of cleaning tanks to clean the front and back sides of the wafer; The second cleaning space includes at least one cleaning station, in which a cleaning liquid is provided to clean the front side of the wafer; The flip structure is used to adjust the direction of the wafer to a vertical direction and transfer it to each of the cleaning tanks, and is used to adjust the direction of the wafer to a horizontal direction and transfer it to the cleaning platform.

2. The wafer cleaning device according to claim 1, wherein: The first cleaning space further includes a drying processing unit, which is used to dry the wafers after being cleaned in the cleaning tank.

3. The wafer cleaning device according to claim 1, wherein: The wafer cleaning device further includes a rinsing tank, which is used to clean the wafers after being cleaned in the cleaning tank, and the cleaning liquid in the rinsing tank is deionized water.

4. The wafer cleaning device according to claim 1, wherein: The flipping structure includes a first robotic arm, a second robotic arm and a third robotic arm. The first robotic arm is used to place the wafer vertically in the cleaning tank. The second robotic arm is used to take the wafer out of the cleaning tank and place the wafer horizontally in a waiting position. The third robotic arm is used to transfer the wafer located in the waiting position to the cleaning table.

5. A wafer cleaning method, characterized in that: The wafer cleaning device according to any one of claims 1 to 4 is used for cleaning, and the wafer cleaning method includes: Performing a first cleaning process, using the flip structure to vertically place the target wafer into the first cleaning space and sequentially clean it through multiple cleaning tanks; and A second cleaning process is performed, whereby the target wafer is flipped to a horizontal position using the flip structure and transferred to the cleaning station for cleaning.

6. The wafer cleaning method according to claim 5, wherein: The plurality of cleaning tanks include a first cleaning tank, a second cleaning tank, and a third cleaning tank, wherein the first cleaning tank is used to provide ozone water for cleaning, the second cleaning tank is used to provide a mixture of liquid ammonia, hydrogen peroxide, and water for cleaning, and the third cleaning tank is used to provide a mixture of hydrochloric acid and hydrogen peroxide for cleaning; When the first cleaning process is performed, the target wafer is cleaned in the first cleaning tank, the second cleaning tank and the third cleaning tank in sequence.

7. The wafer cleaning method according to claim 6, wherein: The process parameters for cleaning in the second cleaning tank are as follows: cleaning temperature of 35-70°C, mass concentration ratio of liquid ammonia to hydrogen peroxide in the mixed liquid of 1:2-0.3:3.5, mixed liquid flow rate of 20-30 L / min, ultrasonic megasonic power of 800-1200 W, and cleaning time of 220-300 s; The process parameters for cleaning in the first cleaning tank and the third cleaning tank are set as follows: the cleaning temperature is room temperature, the flow rate is 20-28 L / min, the ultrasonic megasonic power is 1500-2000 W, the cleaning time is 180-300 s, the ozone water concentration in the first cleaning tank is 25-30 ppm, and the mass concentration ratio of hydrochloric acid to hydrogen peroxide in the third cleaning tank is 1:1-1:

2.

8. The wafer cleaning method according to claim 5, wherein: When performing the first cleaning process, after the target wafer is cleaned in the cleaning tank, the target wafer is dried.

9. The wafer cleaning method according to claim 5, wherein: When the first cleaning process is performed, the target wafers cleaned in each cleaning tank are also rinsed, and the cleaning liquid is deionized water.

10. The wafer cleaning method according to claim 5, wherein: In the second cleaning process, the cleaning station cleans the target wafer using a mixture of ozone water and hydrofluoric acid, and the cleaning cycle is at least twice.

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