TWI837116B - Method and apparatus for cleaning semiconductor wafer - Google Patents

Abstract

The present invention discloses a device and method for ensuring that a silicon wafer is immersed in a chemical liquid during the process of moving from one cleaning tank to another cleaning tank. The device includes an inner tank; at least one partition, which divides the inner tank into at least two cleaning tanks filled with chemical liquid; a first manipulator equipped with at least one pair of end effectors, which is used to grab a silicon wafer and transfer the silicon wafer from the first cleaning tank to the second cleaning tank; wherein, a silicon wafer holder for holding the silicon wafer is provided at the bottom of each cleaning tank, and the partition is provided with at least one slot; wherein, the first manipulator grabs the silicon wafer and transfers the silicon wafer from the first cleaning tank through the slot to the second cleaning tank, and keeps the silicon wafer immersed in the chemical liquid.

Description

Method and device for cleaning semiconductor silicon wafers

The present invention relates to the field of semiconductor device manufacturing, and in particular to a method and device for cleaning semiconductor silicon wafers.

In the integrated circuit manufacturing process, the wet cleaning process is crucial to obtain high-quality integrated circuits. After the dry etching process, the silicon wafer needs to be cleaned to remove residual photoresist, organic matter generated in the dry etching process, and thin film materials adsorbed on the surface of the silicon wafer. The chemical liquids used to clean silicon wafers mainly include SC1, _{BOE ,} and SPM mixed with _H2SO4 and _H2O2 . Among them, the temperature of SPM is higher than 90℃ and SPM is used to remove residual photoresist and organic matter. Generally, there are two ways to clean silicon wafers, one is batch cleaning and the other is single wafer cleaning. The two cleaning methods will be compared below.

Batch cleaning can clean multiple silicon wafers at a time. The batch cleaning device includes mechanical transmission equipment and multiple cleaning tanks. One cleaning tank can clean multiple silicon wafers at the same time, so the efficiency of batch cleaning is high, and about 400 silicon wafers can be cleaned per hour. In addition, since the chemical liquid in the cleaning tank is circulated, the chemical liquid can be reused and the cost of batch cleaning is reduced, especially high-temperature chemical liquid, such as 120℃ SPM, because high-temperature SPM is very difficult to mix and control concentration and temperature. Using batch cleaning can reduce cleaning costs, however, with the continuous reduction of integrated circuit line width, the disadvantages of batch cleaning are clearly exposed. In the batch cleaning process, silicon wafers need to be taken from one cleaning tank to another. At this time, if the chemical liquid in the cleaning tank contains some tiny impurities, such as organic residues, organic pollutants, and particles, the tiny impurities will adhere to the surface of the silicon wafer along with the chemical liquid. Once the silicon wafer is dried or exposed to any gas phase environment, the tiny impurities on the silicon wafer will be very difficult to remove.

Single wafer cleaning can only clean one silicon wafer at a time. The single wafer cleaning device includes mechanical transmission equipment and multiple independent single wafer cleaning modules. The cleaning and drying process of a silicon wafer is completed in a single wafer cleaning module. After cleaning a silicon wafer, the chemical liquid in the single wafer cleaning module is discharged and new chemical liquid is supplied to clean another silicon wafer to avoid cross contamination. Single wafer cleaning can effectively remove particles and thin film materials. However, since high-temperature chemical liquids are difficult to recycle, single wafer cleaning has limitations when using high-temperature chemical liquids, such as SPMs with temperatures above 90°C.

Batch cleaning and single silicon wafer cleaning have their own advantages and disadvantages. Therefore, the invention of a new device and method that combines the advantages of batch cleaning and single silicon wafer cleaning will make a great contribution to the integrated circuit manufacturing process.

Therefore, the present invention provides a device and method to ensure that the silicon wafer is immersed in a chemical liquid during the process of moving from one cleaning tank to another cleaning tank.

According to an embodiment of the present invention, the device includes an inner tank; at least one partition, which divides the inner tank into two cleaning tanks filled with chemical liquid; a first manipulator equipped with at least one pair of end effectors, which is used to grab a silicon wafer and transfer the silicon wafer from the first cleaning tank to the second cleaning tank; wherein, a silicon wafer holder for holding the silicon wafer is provided at the bottom of each cleaning tank, and the partition is provided with at least one slot; wherein, during the process of the first manipulator grabbing the silicon wafer and transferring the silicon wafer from the first cleaning tank through the slot to the second cleaning tank, the silicon wafer is kept immersed in the chemical liquid.

According to an embodiment of the present invention, a method for cleaning semiconductor silicon wafers includes the following steps: placing at least one silicon wafer on a silicon wafer holder in a first cleaning tank filled with chemical liquid; after the silicon wafer is processed in the first cleaning tank, transferring the silicon wafer from the first cleaning tank to a second cleaning tank, wherein the silicon wafer is immersed in the chemical liquid during the transfer process; and after the silicon wafer is processed in the second cleaning tank, taking the silicon wafer out of the second cleaning tank.

The present invention utilizes multiple slots on the partition to transfer the silicon wafer, ensuring that the silicon wafer is immersed in the chemical liquid during the process from the first cleaning tank to another cleaning tank.

1001‧‧‧Inner tank

1002‧‧‧Partition

1003‧‧‧Silicon wafer holder

1004‧‧‧Slot

1005‧‧‧The First Robot

1006‧‧‧External tank

1011‧‧‧First cleaning tank

1012‧‧‧Second cleaning tank

1013‧‧‧Import

1042‧‧‧Liquid channel

1051‧‧‧End Executor

1061‧‧‧Sensor

1062‧‧‧Drain port

1071‧‧‧First liquid inlet

1072‧‧‧First liquid outlet

1073‧‧‧First pump

1074‧‧‧First filter

1081‧‧‧Second liquid inlet

1082‧‧‧Second liquid outlet

1083‧‧‧Second pump

1084‧‧‧Second filter

1085‧‧‧Valve

2004‧‧‧Slots

2041‧‧‧Spray head

2042‧‧‧Liquid channel

2043‧‧‧Slot door

3002‧‧‧Partition

3004‧‧‧Slot

3041‧‧‧Spray head

3042‧‧‧Liquid channel

3043‧‧‧Slot door

3044‧‧‧Opening

4004‧‧‧Slot

4051‧‧‧End executor

4052‧‧‧Drive equipment

5003‧‧‧Silicon wafer holder

5005‧‧‧The First Robot

5008‧‧‧Second robot

5009‧‧‧External cleaning tank

5091‧‧‧Spray nozzle

5092‧‧‧Discharge port

6006‧‧‧External tank

6101‧‧‧Cylinder

6110‧‧‧Cover plate

6111‧‧‧stick-shaped object

6112‧‧‧Rotating mechanism

6121‧‧‧Magnetic components

6122‧‧‧Partition wall

7001‧‧‧Inner tank

7002‧‧‧Partition

7003‧‧‧Silicon wafer holder

7004‧‧‧Slot

7005‧‧‧Robot

7051‧‧‧End executor

8011‧‧‧First cleaning tank

8012‧‧‧Second cleaning tank

9011‧‧‧First cleaning tank

9012‧‧‧Second cleaning tank

9013‧‧‧Third cleaning tank

Figures 1A-1C are cross-sectional views of an embodiment of an apparatus for cleaning semiconductor silicon wafers during a silicon wafer transfer process; Figure 2A is a cross-sectional view of an embodiment of a partition having a slot; Figure 2B is an embodiment of a partition having a slot with a door open; Figure 2C is an embodiment of a partition having a slot with a door closed; Figure 3A is a cross-sectional view of another embodiment of a partition having multiple slots; Figure 3B is another embodiment of a partition having multiple slots with a door open; Figure 3C is another embodiment of a partition having multiple slots with a door closed; Figure 4A is a side view of a partition having vertical slots and a robot arm matching the slots; Figure 4B is a side view of a partition having vertical slots and a robot arm matching the slots. FIG4 is a side view of a partition with a horizontal slot and a manipulator matched with the slot; FIG4C is a side view of a partition with a slot at a certain angle to the horizontal direction and a manipulator matched with the slot; FIG5 is a cross-sectional view of an embodiment of a device with an external cleaning tank; FIG6A is a cross-sectional view of an embodiment of a device for cleaning semiconductor silicon wafers during the cleaning process; FIG6B is a side view of a magnetic drive structure of an embodiment of a device for cleaning semiconductor silicon wafers during the cleaning process; FIG7 is a cross-sectional view of another embodiment of a device for cleaning semiconductor silicon wafers according to the present invention; FIG8A-8F are an embodiment of a method for cleaning semiconductor silicon wafers; FIG9A-9C are another embodiment of a method for cleaning semiconductor silicon wafers.

The specific implementation of the present invention is described in detail below with reference to the attached drawings. The following embodiments are only used to illustrate the present invention, not to limit the present invention.

FIG. 1A is a cross-sectional view of an embodiment of an apparatus for cleaning semiconductor wafers according to the present invention. The device for cleaning semiconductor silicon wafers includes an inner tank 1001; at least one partition 1002, which divides the inner tank 1001 into two cleaning tanks filled with chemical liquid; a first manipulator 1005 equipped with at least one pair of end effectors 1051, which is used to grab the silicon wafer and transfer the silicon wafer from the first cleaning tank 1011 to the second cleaning tank 1012; wherein, a silicon wafer holder 1003 for holding the silicon wafer is provided at the bottom of each cleaning tank, and the partition 1002 is provided with at least one slot 1004; wherein, the first manipulator 1005 grabs the silicon wafer and transfers the silicon wafer from the first cleaning tank 1011 through the slot 1004 to the second cleaning tank 1012, and in this process, keeps the silicon wafer immersed in the chemical liquid. The silicon wafer holder 1003 can move forward and backward.

The chemical liquid in the cleaning tank is high temperature SPM, and the temperature of _SPM is 80℃-250℃. The temperature of the chemical liquid in different cleaning tanks is the same or different. SPM is a mixture of _H2SO4 and _H2O2 , and the ratio of _H2O2 to _H2SO4 is 1: ₁ to 1: ₁₀₀ . The concentration _of the chemical liquid in different cleaning tanks is the same or different.

In order to prevent the dirty chemical liquid in the first cleaning tank 1011 from flowing to the second cleaning tank 1012, there is a liquid level difference between the two cleaning tanks, that is, the liquid level of the first cleaning tank 1011 is lower than the liquid level of the second cleaning tank 1012. Due to the liquid level difference between the first cleaning tank 1011 and the second cleaning tank 1012, the chemical liquid pressure P2 in the second cleaning tank 1012 is higher than the chemical liquid pressure P1 in the first cleaning tank 1011, and a pressure difference △P=P2-P1>0, P2>P1 is formed between the first cleaning tank 1011 and the second cleaning tank 1012. Due to the pressure difference △P, the chemical liquid in the second cleaning tank 1012 will flow to the first cleaning tank 1011. The second cleaning tank 1012 is provided with an inlet 1013 for supplying fresh chemical liquid to the second cleaning tank 1012 to maintain a liquid level difference between the two cleaning tanks.

The device further includes an outer tank 1006. Each cleaning tank is connected to the outer tank 1006 through a circulation system. The circulation system connected to the first cleaning tank 1011 includes a first liquid inlet 1071, a first liquid outlet 1072, a first pump 1073 and a first filter 1074. The first liquid inlet 1071 is located at the bottom of the first cleaning tank 1011, and the first liquid outlet 1072 is located at the bottom of the outer tank 1006. The circulation system connected to the second cleaning tank 1012 includes a second liquid inlet 1081, a second liquid outlet 1082, a second pump 1083, a second filter 1084 and a valve 1085. The second liquid inlet 1081 is located at the bottom of the second cleaning tank 1012, the second liquid outlet 1082 is located at the bottom of the outer tank 1006, and the valve 1085 is connected to the liquid channel 1042 in the partition 1002 to control the supply of the chemical liquid. During the cleaning process, the chemical liquid in the first cleaning tank 1011 becomes dirtier and dirtier, and the dirty chemical liquid in the first cleaning tank 1011 overflows and flows into the outer tank 1006. The dirty chemical liquid in the outer tank 1006 flows into the circulation system through the first liquid outlet 1072. The circulation system purifies the dirty chemical liquid through the first filter 1074, and the clean chemical liquid returns to the first cleaning tank 1011 through the first liquid inlet 1071. In this way, the chemical liquid in the cleaning tank is always kept clean. Furthermore, the height of the partition 1002 is not lower than the height of the cleaning tank to avoid cross contamination between the two cleaning tanks.

The outer tank 1006 also includes a sensor 1061 and a drain port 1062 located below the sensor 1061. The sensor 1061 is used to detect the liquid level of the chemical solution in the outer tank 1006. The inlet 1013 continuously supplies fresh chemical solution to the second cleaning tank 1012, and the chemical solution in the second cleaning tank 1012 flows to the first cleaning tank 1011, and then the chemical solution in the first cleaning tank 1011 overflows into the outer tank 1006. When the sensor 1061 detects that the liquid level rises to a set height, the drain port 1062 will be opened and the chemical solution will be discharged until the liquid level is lower than the set height.

Figures 1A-1C describe the working process of the first robot 1005. After the cleaning process is completed, the first robot 1005 is placed in two adjacent cleaning tanks, and each pair of end effectors 1051 passes through two adjacent cleaning tanks. Multiple pairs of end effectors 1051 grab the silicon wafer at the same time, and the first robot 1005 pulls the silicon wafer to a specific height, and then the silicon wafer moves horizontally with the first robot 1005, so that the silicon wafer passes through the slot 1004 on the partition 1002 from the first cleaning tank 1011 to the second cleaning tank 1012. The first robot 1005 lowers the silicon wafer and places the silicon wafer on the silicon wafer holder 1003 in the second cleaning tank 1012.

The partition 1002 with the slot 1004 prevents the silicon wafer from being exposed to the non-liquid environment during the transfer process from one cleaning tank to another cleaning tank, but the dirty chemical liquid in the first cleaning tank 1011 will flow to the second cleaning tank 1012 through the slot 1004. FIG2A is a cross-sectional view of an embodiment of the partition 1002 with a slot 2004. A row of nozzles 2041 are provided on at least one side wall of the slot 2004. The chemical liquid sprayed by the nozzle 2041 is provided by the second cleaning tank. Specifically, the chemical liquid is supplied to the nozzle 2041 from the circulation system through the liquid channel 2042, and the valve of the circulation system is kept open. When the silicon wafer passes through the slot 2004, the nozzle 2041 sprays fresh chemical liquid on both sides of the silicon wafer. In addition, the chemical liquid sprayed by the nozzle 2041 forms a liquid curtain to block the slot 2004, and the liquid curtain can prevent the dirty chemical liquid from flowing through the slot 2004 to the clean chemical liquid. The pressure difference between the two cleaning tanks can also help reduce the dirty chemical liquid from flowing from the first cleaning tank 1011 to the second cleaning tank 1012. In order to further block the slot 2004 to prevent the dirty chemical liquid from flowing to the clean chemical liquid, the device also includes a slot door 2043, as shown in Figures 2B and 2C. The slot door 2043 is driven by a driving device to seal or open the slot 2004. When the silicon wafers are processed, the slot door 2043 is opened, and then the nozzle 2041 sprays the chemical liquid and transfers the silicon wafers one by one. In other cases, the slot door 2043 is closed.

FIG. 3A is a cross-sectional view of another embodiment of a partition 3002 having a plurality of slots 3004. A row of nozzles 3041 are provided on the sidewalls of each slot 3004, and chemical liquid is supplied to the nozzles 3041 from a circulation system through a liquid channel 3042, and the valve of the circulation system remains open. When the silicon wafer passes through the slot 3004, the nozzles 3041 spray fresh chemical liquid on both sides of the silicon wafer. In addition, the chemical liquid sprayed by the nozzles 3041 forms a liquid curtain to block the slot 3004, and the liquid curtain can prevent dirty chemical liquid from flowing through the slot 3004 to the clean chemical liquid. The pressure difference between the two cleaning tanks can also help reduce the flow of dirty chemical liquid from the first cleaning tank to the second cleaning tank. In order to further block all slots 3004 to prevent dirty chemical liquid from flowing to clean chemical liquid, the device also includes a slot door 3043, as shown in Figures 3B and 3C. The slot door 3043 is provided with a plurality of openings 3044, and the number of openings 3044 is not less than the number of slots 3004 on the partition 3002, and the size of the openings 3044 is not less than the size of the slots 3004 on the partition 3002. The slot door 3043 is driven by a driving device to seal or open the slot 3004. When the silicon wafer is processed, the slot door 3043 is moved until the opening 3044 overlaps with the slot 3004, and then the nozzle 3041 sprays the chemical liquid and transfers the silicon wafer. In other cases, the slot 3004 and the opening 3044 are misaligned.

If the first manipulator is equipped with a pair of end effectors, then the silicon wafers are delivered one by one. In order to speed up the delivery efficiency, the number of pairs of end effectors is the same as the number of silicon wafers, that is, all silicon wafers can be delivered at one time. Preferably, the number of pairs of end effectors is 5 to 25 pairs. The shape of the first manipulator is like a rake, as shown in Figures 4A-4C. The first manipulator includes a driving device 4052 for driving the first manipulator to rise and fall. The first manipulator is used to grab silicon wafers and transfer the silicon wafers from the first cleaning tank to the second cleaning tank. The shape of the first manipulator is conducive to each pair of end effectors 4051 passing through the slots, so the number of pairs of end effectors 4051 cannot be more than the number of slots. 4A-4C are side views of a partition with slots in different directions and a manipulator matching the slots. The slot 4004 shown in FIG4A is vertical, and the direction of the end effector 4051 is also vertical. The number of end effectors 4051 is 5 pairs, and the number of slots 4004 is 5. In this case, the silicon wafer is placed vertically on the silicon wafer holder, and the liquid inlet is located at the bottom of the cleaning tank. The slot 4004 shown in FIG4B is horizontal, and the direction of the end effector 4051 is also horizontal. The number of end effectors 4051 is 5 pairs, and the number of slots 4004 is 5. In this case, the silicon wafer is placed horizontally on the silicon wafer holder, and the liquid inlet is located at the side wall of the cleaning tank. The slot 4004 shown in FIG. 4C is at a certain angle to the horizontal direction, and the direction of the end effector 4051 is the same as that of the slot 4004. The number of the end effectors 4051 is 5 pairs, and the number of the slots 4004 is 5. In this case, the silicon wafer is placed on the silicon wafer holder at a certain angle to the horizontal direction, the angle of the silicon wafer to the horizontal direction is the same as the angle of the slot 4004 to the horizontal direction, and the liquid inlet is at a certain angle to the horizontal direction.

Considering that the first manipulator can only lift the silicon wafer to a certain height, the device also includes a second manipulator 5008 for loading and unloading the silicon wafer. FIG5 is a cross-sectional view of an embodiment of a device with an external cleaning tank. Before the cleaning process starts, the second manipulator 5008 is used to place the silicon wafer on the silicon wafer holder 5003 in the cleaning tank. After the entire cleaning process is completed, the second manipulator 5008 is used to take the silicon wafer out of the cleaning tank. The second manipulator 5008 is placed in the external cleaning tank 5009 in a non-working state. The side wall of the external cleaning tank 5009 is provided with a plurality of nozzles 5091 to spray deionized water or fresh chemical solution to rinse the second manipulator 5008. The bottom of the external cleaning tank 5009 is provided with a drain port 5092 for discharging dirty chemical solution. The external cleaning tank 5009 can also be used to clean the first robot 5005.

FIG6A is a cross-sectional view of an embodiment of a device for cleaning silicon wafers during a cleaning process. Each cleaning tank is provided with a cover plate 6110 to prevent leakage of chemical liquid or diffusion of chemical vapor to other areas of the device during the cleaning process. The cover plate 6110 is provided with a cylinder 6101 for driving the cover plate 6110 to move up and down. As the liquid sprays out from the liquid inlet and flows out of the cleaning tank, the circulating flow of the liquid causes the silicon wafer on the silicon wafer holder to vibrate, and the vibration causes the silicon wafer to bounce up and down on the silicon wafer holder, thereby causing defects at the contact point between the silicon wafer and the silicon wafer holder. To solve this problem, the silicon wafer is locked with three sticks 6111, one of which is connected to the cover plate 6110, so that the stick 6111 connected to the cover plate 6110 presses down the silicon wafer to fix the silicon wafer on the silicon wafer holder. The other two sticks 6111 are located on the silicon wafer holder to lock the silicon wafer in the horizontal direction. During the cleaning process, the contact points between the silicon wafer and the two sticks will produce relative movement and cause defects. In order to reduce this defect, the stick 6111 connected to the cover plate 6110 is driven by the rotating mechanism 6112 as a rotating roller, and the other sticks are rotated as driven rollers, thereby driving the silicon wafer to rotate together, as shown in Figure 6A. The rotating mechanism 6112 is provided with a magnetic component 6121, and the magnetic component 6121 is made of a magnetic material. The magnetic component 6121 is inserted into the outer groove 6006, and a plurality of partition walls 6122 are provided around the magnetic component 6121 to form a specific space to prevent the chemical liquid from contacting the magnetic component 6121. The end of the stick 6111 connected to the cover 6110 close to the magnetic component 6121 is made of a magnetic material, and the stick 6111 connected to the cover 6110 and the magnetic component 6121 use a magnetic material with the same characteristics. The magnetic component 6121 is rotated to drive the stick 6111 to rotate, and the rotation of the stick 6111 drives the silicon wafer to rotate.

FIG7 is a cross-sectional view of another embodiment of the device for cleaning semiconductor silicon wafers according to the present invention. The device for cleaning semiconductor silicon wafers includes an inner tank 7001 having a partition 7002, the partition 7002 dividing the inner tank 7001 into two cleaning tanks filled with chemical liquid; a silicon wafer holder 7003 provided at the bottom of each cleaning tank for holding silicon wafers; the partition 7002 is provided with at least one slot 7004; a manipulator 7005 equipped with at least one pair of end effectors 7051 for grabbing at least one silicon wafer from the first cleaning tank through the slot 7004 to the second cleaning tank, and keeping the silicon wafer immersed in the chemical liquid. The slot 7004 penetrates the upper part of the partition 7002, so that the manipulator 7005 can load and unload silicon wafers.

Figures 8A-8F are an embodiment of a silicon wafer cleaning method. A silicon wafer cleaning method includes: placing at least one silicon wafer on a silicon wafer holder in a first cleaning tank 8011 filled with chemical liquid; after the silicon wafer is processed in the first cleaning tank 8011, transferring the silicon wafer from the first cleaning tank 8011 to the second cleaning tank 8012, and the silicon wafer is immersed in the chemical liquid during the transfer process; after the silicon wafer is processed in the second cleaning tank 8012, taking the silicon wafer out of the second cleaning tank 8012.

As shown in Figures 8A-8F, the transfer method of the silicon wafers is to transfer the silicon wafers from the first cleaning tank 8011 to the second cleaning tank 8012 one by one. During the transfer process, a chemical liquid is sprayed between the first cleaning tank 8011 and the second cleaning tank 8012 to form a liquid curtain.

Figures 9A-9C are another embodiment of a silicon wafer cleaning method. A silicon wafer cleaning method includes: placing at least one silicon wafer on a silicon wafer holder in a first cleaning tank 9011 filled with chemical liquid; after the silicon wafer is processed in the first cleaning tank 9011, transferring the silicon wafer from the first cleaning tank 9011 to the third cleaning tank 9013; after the silicon wafer is processed in the third cleaning tank 9013, transferring the silicon wafer from the third cleaning tank 9013 to the second cleaning tank 9012, and the silicon wafer is immersed in the chemical liquid during the transfer process; After the silicon wafer is processed in the second cleaning tank 9012, taking the silicon wafer out of the second cleaning tank 9012.

As shown in Figures 9A-9C, the transfer method of the silicon wafers is to transfer all the silicon wafers from one cleaning tank to another cleaning tank at a time. During the transfer process of the silicon wafers, chemical liquid is sprayed between every two cleaning tanks to form a liquid curtain.

1001‧‧‧Inner tank

1002‧‧‧Partition

1003‧‧‧Silicon wafer holder

1004‧‧‧Slot

1005‧‧‧The First Robot

1006‧‧‧External tank

1011‧‧‧First cleaning tank

1012‧‧‧Second cleaning tank

1013‧‧‧Import

1051‧‧‧End Executor

1061‧‧‧Sensor

1062‧‧‧Drain port

1071‧‧‧First liquid inlet

1072‧‧‧First liquid outlet

1073‧‧‧First pump

1074‧‧‧First filter

1081‧‧‧Second liquid inlet

1082‧‧‧Second liquid outlet

1083‧‧‧Second pump

1084‧‧‧Second filter

1085‧‧‧Valve

Claims (35)

A device for cleaning semiconductor silicon wafers, comprising: an inner tank; at least one partition, dividing the inner tank into at least two cleaning tanks filled with chemical liquid; a first manipulator equipped with at least one pair of end effectors, used to grab a silicon wafer and transfer the silicon wafer from the first cleaning tank to the second cleaning tank; wherein, a silicon wafer holder for holding the silicon wafer is provided at the bottom of each cleaning tank, and the at least one partition is provided with at least one slot; wherein, during the process of the first manipulator grabbing the silicon wafer and transferring the silicon wafer from the first cleaning tank through the slot to the second cleaning tank, the silicon wafer is kept immersed in the chemical liquid, wherein the liquid level of the first cleaning tank is lower than the liquid level of the second cleaning tank. The device as described in claim 1, wherein the chemical liquid is SPM, and the temperature of the SPM is between 80℃ and 250℃. The device as described in claim 2, wherein the SPM is a mixture of H ₂ SO ₄ and H ₂ O ₂ , and the ratio of the H ₂ O ₂ to the H ₂ SO ₄ is 1:1 to 1:100. The device as described in claim 1, wherein the chemical liquid in the first cleaning tank and the chemical liquid in the second cleaning tank have the same temperature. The device as described in claim 1, wherein the chemical liquid in the first cleaning tank and the chemical liquid in the second cleaning tank have different temperatures. The device as described in claim 1, wherein the concentration of the chemical liquid in the first cleaning tank is the same as that of the chemical liquid in the second cleaning tank. The device as described in claim 1, wherein the concentration of the chemical liquid in the first cleaning tank is different from that in the second cleaning tank. The device as described in claim 1 also includes an outer tank, each of the cleaning tanks is connected to the outer tank, and the chemical liquid is circulated back to each of the cleaning tanks through a circulation system. The device as described in claim 8, wherein the circulation system includes a liquid inlet located in the cleaning tank. The device as described in claim 9, wherein the liquid inlet is located at the bottom of the cleaning tank. The device as described in claim 9, wherein the liquid inlet is located on the side wall of the cleaning tank. A device as described in claim 9, wherein the liquid inlet is at a certain angle to the horizontal direction. The device as described in claim 8, wherein the second cleaning tank is provided with an inlet for providing the chemical liquid. The device as described in claim 13, wherein the outer tank further includes a sensor and a drain port located below the sensor, and the sensor is used to detect the liquid level of the chemical liquid in the outer tank. The device as described in claim 1, wherein the height of at least one partition is not lower than the height of the cleaning tank. The device as described in claim 1, wherein the chemical liquid in the second cleaning tank is fresher than the chemical liquid in the first cleaning tank. The device as described in claim 1, wherein the slot has at least one side wall provided with a row of nozzles for spraying the chemical liquid to form a liquid curtain. The device as described in claim 17, wherein the chemical liquid sprayed by the nozzle is provided by the second cleaning tank. The device as described in claim 1 also includes a slot door for sealing or opening the slot. A device as claimed in claim 1, wherein the number of pairs of end effectors is no greater than the number of slots. The device as claimed in claim 1, wherein the first manipulator equipped with more than one pair of end effectors is shaped like a rake. A device as claimed in claim 1, wherein the number of end effectors is 1 to 25 pairs. A device as described in claim 1, wherein the silicon wafer holder moves back and forth. A device as claimed in claim 1, wherein at least one of the slots is vertical. A device as claimed in claim 1, wherein at least one of the slots is horizontal. A device as claimed in claim 1, wherein at least one of the slots is at an angle to the horizontal. The device as described in claim 1 further includes a cover plate and three stick-shaped objects, wherein the stick-shaped objects connected to the cover plate press down the silicon wafer to fix the silicon wafer on the silicon wafer holder. The device as described in claim 27, wherein the other two of the three sticks are located on the silicon wafer holder to lock the silicon wafer in the horizontal direction. As described in claim 28, the stick-shaped object connected to the cover plate is driven by a rotating mechanism as a rotating roller, and the other stick-shaped objects are driven as driven rollers to rotate, thereby driving the silicon wafer to rotate together. The device as described in claim 1 also includes a second robot for loading and unloading the silicon wafer. The device as described in claim 1 also includes an external cleaning tank for cleaning the first robot. A device as claimed in claim 1, wherein the at least one slot penetrates the upper portion of the at least one partition. A method for cleaning semiconductor silicon wafers, comprising: placing at least one silicon wafer on a silicon wafer holder in a first cleaning tank filled with chemical liquid; After the at least one silicon wafer is processed in the first cleaning tank, transferring the at least one silicon wafer from the first cleaning tank to a second cleaning tank, and immersing the at least one silicon wafer in the chemical liquid during the transfer process; after the at least one silicon wafer is processed in the second cleaning tank, taking the at least one silicon wafer out of the second cleaning tank, wherein the liquid level of the first cleaning tank is lower than the liquid level of the second cleaning tank. The method as claimed in claim 33 further comprises the steps of: after the at least one silicon wafer is processed in the first cleaning tank, first transferring the at least one silicon wafer from the first cleaning tank to the third cleaning tank, and after the at least one silicon wafer is processed in the third cleaning tank, then transferring the at least one silicon wafer from the third cleaning tank to the second cleaning tank. The method as described in claim 33 further includes the step of spraying the chemical liquid to form a liquid curtain between the first cleaning tank and the second cleaning tank.

Images