TWI840464B - Apparatus and method for cleaning semiconductor wafers - Google Patents

Abstract

The present invention provides methods and apparatuses for cleaning semiconductor wafers. Thereinto, a method comprises transferring one or more wafers to at least one first tank containing cleaning chemical, one or more second tanks containing cleaning liquid successively for implementing batch cleaning process; taking the one or more wafers out of the cleaning liquid in the one or more second tanks and transferring the one or more wafers to one or more single wafer cleaning modules for implementing single wafer cleaning and drying processes; wherein control and keep a certain thickness of liquid film on the one or more wafers from the moment of the one or more wafers out of the cleaning chemical in the at least one first tank till the one or more wafers are immersed in the cleaning liquid of the one or more second tanks, and/or from the moment of the one or more wafers out of the cleaning liquid in the one or more second tanks till the one or more wafers are transferred to the one or more single wafer cleaning modules.

Description

Device and method for cleaning semiconductor silicon wafers

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

In the manufacturing process of integrated circuits, 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 the residual photoresist, organic matter and thin film material attached to the surface of the silicon wafer in the dry etching process. The chemical liquid used to clean the silicon wafer mainly includes: for example, SC1, BOE and SPM solution mixed with sulfuric acid and hydrogen peroxide. Among them, the temperature of the SPM solution may be higher than 80°C, and the high-temperature SPM solution can be used to remove residual photoresist and organic matter. Generally speaking, there are two methods for cleaning silicon wafers, one is tank cleaning and the other is single-wafer cleaning.

Tank cleaning can clean multiple silicon wafers at one time. Tank cleaning devices include: mechanical transmission devices and multiple cleaning tanks. Multiple silicon wafers can be cleaned simultaneously in one cleaning tank, so the efficiency of tank cleaning is very high. In addition, since the chemical solution in the cleaning tank is circulated, the chemical solution can be reused, which reduces the cost of tank cleaning, especially for high-temperature chemical solutions, such as 120°C SPM solutions. Since high-temperature SPM solutions are more expensive, using tank cleaning can reduce cleaning costs. However, as the width of integrated circuits continues to shrink, the shortcomings of tank cleaning are increasingly exposed. In the tank cleaning process, the silicon wafer is placed vertically in the cleaning tank, which can easily lead to cross-contamination between silicon wafers. In particular, if one of the silicon wafers in one of the cleaning tanks has metal or organic contaminants, all silicon wafers cleaned in the same cleaning tank will be contaminated. After cleaning, the silicon wafer is taken out of the cleaning tank vertically. At this time, if the chemical liquid in the cleaning tank contains some tiny organic contaminants or particles, these tiny organic contaminants or particles will adhere to the surface of the silicon wafer along with the chemical liquid. Once the silicon wafer is dried, these tiny organic contaminants or particles on the silicon wafer will be difficult to remove.

Single-wafer cleaning can only clean one silicon wafer at a time. The single-wafer cleaning device includes: a mechanical transmission device and multiple independent single-wafer cleaning modules. The drying and cleaning processes of a silicon wafer are 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 the single-wafer cleaning module for cleaning another silicon wafer, effectively avoiding cross contamination. Single-wafer cleaning can effectively remove particles and thin film materials and avoid metal ion contamination. However, single-wafer cleaning has certain limitations in the use of high-temperature chemical liquids, such as SPM solutions with temperatures above 130°C. Because high-temperature chemical liquids are difficult to recycle, a large amount of SPM solution is required. In addition, single-wafer cleaning is more suitable for cleaning the front of silicon wafers, and there are certain difficulties and challenges in cleaning the back of silicon wafers. In some cases, single-wafer cleaning takes a long time to clean silicon wafers, resulting in low yields.

Both tank cleaning and single-wafer cleaning have their own advantages and disadvantages. Using only tank cleaning or single-wafer cleaning cannot achieve the best cleaning effect, nor can it meet the needs of modern processes. Therefore, the idea of combining tank cleaning and single-wafer cleaning is proposed. However, a major challenge of combining tank cleaning and single-wafer cleaning is that it is difficult to control the particles and contaminants in the tank cleaning solution so that they do not adhere to the silicon wafer during the period when the silicon wafer is taken out of the cleaning solution in the cleaning tank and transferred to the single-wafer cleaning module. During this period, if particles and contaminants adhere to the surface of the silicon wafer, it will be difficult to remove these particles and contaminants in the single-wafer cleaning module.

Therefore, the present invention proposes a device and method for cleaning semiconductor silicon wafers.

According to an embodiment of the present invention, a method for cleaning a semiconductor wafer is provided. The method comprises: transferring one or more silicon wafers to at least one first tank containing chemical liquid and one or more second tanks containing cleaning liquid in sequence for tank cleaning; taking out the one or more silicon wafers from the cleaning liquid in the one or more second tanks and transferring the one or more silicon wafers to one or more single-wafer cleaning modules for cleaning and drying of the single silicon wafers; wherein, from the moment when the one or more silicon wafers are taken out from the chemical liquid in the at least one first tank until the one or more silicon wafers are immersed in the cleaning liquid in the one or more second tanks, and/or from the moment when the one or more silicon wafers are taken out from the cleaning liquid in the one or more second tanks until the one or more silicon wafers are transferred to the one or more single-wafer cleaning modules, a certain thickness of liquid film is controlled and maintained on the one or more silicon wafers.

According to another embodiment of the present invention, a method for cleaning semiconductor silicon wafers is proposed. The method comprises: transferring one or more silicon wafers to at least one tank containing a cleaning solution for tank cleaning; taking the one or more silicon wafers out of the cleaning solution in the at least one tank and transferring them to one or more single-wafer cleaning modules for cleaning and drying the single-wafer silicon wafers; wherein, from the moment when the one or more silicon wafers are taken out of the cleaning solution in the at least one tank until the one or more silicon wafers are transferred to the one or more single-wafer cleaning modules, a certain thickness of liquid film is controlled and maintained on the one or more silicon wafers.

According to an embodiment of the present invention, a device for cleaning semiconductor silicon wafers is provided. The device includes: at least one first tank containing chemical liquid, configured to perform a tank cleaning process; one or more second tanks containing cleaning liquid, configured to perform a tank cleaning process; one or more single-wafer cleaning modules, configured to perform a cleaning and drying process of a single silicon wafer; multiple manipulators, configured to transfer one or more silicon wafers; a controller, configured to control the multiple manipulators to sequentially transfer one or more silicon wafers to the at least one first tank and the one or more second tanks, and then transfer them to the at least one first tank and the one or more second tanks. The controller is configured to maintain a certain thickness of liquid film on the one or more silicon wafers from the moment when the one or more silicon wafers are taken out of the chemical liquid in the at least one first tank until the one or more silicon wafers are immersed in the cleaning liquid in the one or more second tanks, and/or from the moment when the one or more silicon wafers are taken out of the cleaning liquid in the one or more second tanks until the one or more silicon wafers are transferred to the one or more single-wafer cleaning modules.

According to another embodiment of the present invention, a device for cleaning semiconductor silicon wafers is proposed. The device includes: multiple loading ports; at least one first tank containing chemical liquid, configured to perform a tank cleaning process; one or more second tanks containing cleaning liquid, configured to perform a tank cleaning process; one or more single-wafer cleaning modules, configured to perform a cleaning and drying process of a single silicon wafer; wherein the multiple loading ports are arranged horizontally, the at least one first tank and the one or more second tanks are arranged vertically on one side, and the one or more single-wafer cleaning modules are arranged vertically on the other side and are located opposite to the at least one first tank and the one or more second tanks.

According to another embodiment of the present invention, a device for cleaning semiconductor silicon wafers is proposed. The device includes: at least one tank containing a cleaning solution, configured to perform a tank cleaning process; one or more single-wafer cleaning modules, configured to perform a cleaning and drying process of a single silicon wafer; one or more manipulators, configured to transfer one or more silicon wafers to the at least one tank and the one or more single-wafer cleaning modules; a controller, configured to control the one or more manipulators; wherein the controller is configured to maintain a certain thickness of liquid film on the one or more silicon wafers from the moment the one or more silicon wafers are taken out of the cleaning solution in the at least one tank until the one or more silicon wafers are transferred to the one or more single-wafer cleaning modules.

102: Silicon wafer

104: Liquid film

106: Particles

201: First slot

202: Silicon wafer

203: First nozzle

204: Liquid film

205: Second nozzle

207: Second slot

208: The third nozzle

502: Support seat

504: Liquid film

506: Process robot

508: The fourth nozzle

510: Single chip cleaning module

602: Support seat

604: Liquid film

606: Process robot

608: The fourth nozzle

610: Single chip cleaning module

701: First slot

702: Silicon wafer

704: Liquid film

707: Second slot

802: Silicon wafer

804: Liquid film

806: Particles

902: Silicon wafer

904: Liquid film

1000: Device for cleaning semiconductor silicon wafers

1010: Loading port

1020: Front-end robot

1030: First flipping device

1031: Base

1032: Support frame

1033: Rotating axis

1034: First drive device

1035: Silicon wafer holding device

1036: Rotation axis

1037: Second drive device

1038: Lifting device

1040: Cleaning tank

1050: First slot

1060: Second slot

1070: Second flipping device

1071: Receiving chamber

1072: Silicon wafer holder

1073: First drive mechanism

1074: Support seat

1075:Support rod

1076: Second drive mechanism

1077:Window

1078: Door

1079: The third drive mechanism

1080: Process robot

1090: Single chip cleaning module

1100: Buffer room

1200: Chemical liquid supply system

1300: Power control system

1301: Silicon wafer box

1302: Silicon wafer

1501: Clamping arm

1502: Clip slot

1503: Nozzle device

1504: Slit nozzle

1505: Liquid inlet

1900: Cleaning fluid

The above and other objects, features and advantages of the present invention will become more apparent by describing in more detail exemplary embodiments of the present invention in conjunction with the accompanying drawings, in which the same figure reference numerals generally represent the same elements.

Figure 1A reveals that a thin liquid film may cause particles to adhere to the silicon wafer surface.

Figure 1B reveals that the thick liquid film keeps the particles away from the silicon wafer surface.

Figures 2A to 2F reveal schematic diagrams of controlling and maintaining a certain thickness of a liquid film on a silicon wafer from the moment the silicon wafer emerges from the liquid in the first tank until the silicon wafer is completely taken out of the first tank according to an embodiment of the present invention.

Figures 3A to 3E disclose schematic diagrams of controlling and maintaining a certain thickness of a liquid film on a silicon wafer from the moment the silicon wafer rotates above the second tank until the silicon wafer is completely immersed in the liquid in the second tank according to an embodiment of the present invention.

Figures 4A to 4D reveal schematic diagrams of controlling and maintaining a certain thickness of a liquid film on a silicon wafer from the moment the silicon wafer emerges from the liquid in the second tank until the silicon wafer is completely taken out of the second tank according to an embodiment of the present invention.

Figures 5A to 5H disclose schematic diagrams of controlling and maintaining a certain thickness of a liquid film on a silicon wafer from the time the silicon wafer is transferred to the second flipping device until the silicon wafer is transferred to the single-wafer cleaning module and the liquid is sprayed onto the silicon wafer in the single-wafer cleaning module according to an embodiment of the present invention.

Figures 6A to 6J disclose another embodiment of the present invention, from the time when the silicon wafer is transferred to the second flipping device until the silicon wafer is transferred to the single-wafer cleaning module and the liquid is sprayed onto the silicon wafer in the single-wafer cleaning module, a schematic diagram of controlling and maintaining a liquid film of a certain thickness on the silicon wafer.

Figures 7A and 7B reveal schematic diagrams of controlling and maintaining a certain thickness of a liquid film on a silicon wafer from the time the silicon wafer is taken out of the first tank to the time the silicon wafer is placed in the second tank according to an embodiment of the present invention.

FIG8A reveals that according to the present invention, when the thickness of the liquid film on the silicon wafer is greater than the diameter of the particles of interest, these particles of interest may not adhere to the surface of the silicon wafer, and FIG8B and FIG8C reveal that according to the present invention, if the thickness of the liquid film on the silicon wafer is equal to or less than the diameter of the particles of interest, these particles of interest may adhere to the surface of the silicon wafer.

Figures 9A to 9C show schematic diagrams of three liquid film modes formed on a silicon wafer by controlling the tilting time of the silicon wafer, the tilting angle of the silicon wafer, and the acceleration of the robot when transferring the silicon wafer.

FIG10 discloses a top view of a cleaning device according to an embodiment of the present invention.

FIG. 11 discloses a perspective view of the cleaning device shown in FIG. 10 .

FIG. 12 discloses another perspective view of the cleaning device shown in FIG. 10 .

Figure 13 shows a schematic diagram of the front-end robot taking a silicon wafer from a silicon wafer box.

Figures 14A to 14D disclose schematic diagrams of the flipping process of a silicon wafer placed in a first flipping device according to an embodiment of the present invention.

FIG. 15 discloses a perspective view of a clamping arm of a second silicon wafer transfer robot according to an embodiment of the present invention.

FIG16 discloses a cross-sectional view of the clamping arm of the second manipulator shown in FIG15.

FIG. 17 discloses a perspective view of a second flipping device according to an embodiment of the present invention.

FIG18 discloses a cross-sectional view of the second flipping device shown in FIG17 .

FIG19 shows a schematic diagram of an embodiment of the present invention, in which a second robot places two silicon wafers on a support seat of a second flipping device, wherein liquid is continuously sprayed on the two silicon wafers.

Figure 20 is a cross-sectional view of Figure 19.

FIG21 discloses a schematic diagram of an embodiment of the present invention, in which two silicon wafers are held by a silicon wafer holder of a second flipping device and separated from a supporting seat of the second flipping device, wherein liquid is always sprayed on the two silicon wafers.

FIG22 discloses a schematic diagram of stopping spraying liquid on two silicon wafers and turning the two silicon wafers from a vertical plane to a horizontal plane; FIG23 discloses a schematic diagram of the second flipping device turning the two silicon wafers from a horizontal plane to an inclined plane; FIG24 discloses a schematic diagram of the second flipping device turning the two silicon wafers from an inclined plane to a horizontal plane.

Figure 25 shows a schematic diagram of the process robot taking out two silicon wafers from the second flipping device.

FIG26 shows a schematic diagram of an embodiment of the present invention, in which a second robot places a silicon wafer on a support seat of a second flipping device, wherein liquid is continuously sprayed on the silicon wafer.

FIG27 discloses a schematic diagram of an embodiment of the present invention, in which a silicon wafer is held by a silicon wafer holder of a second flipping device and separated from a supporting seat of the second flipping device, wherein liquid is always sprayed on the silicon wafer.

Figure 28 shows a schematic diagram of a second flipping device turning a silicon wafer from a vertical surface to an inclined surface, wherein the liquid is always sprayed on the silicon wafer.

Figure 29 shows a schematic diagram of a second flipping device turning a silicon wafer from an inclined plane to a horizontal plane, wherein the liquid is always sprayed on the silicon wafer.

Figures 30A to 30C disclose schematic diagrams of another method for controlling and maintaining a liquid film of a certain thickness on a silicon wafer by controlling a robot according to an embodiment of the present invention.

In order to fully utilize the greatest advantages of tank cleaning and single-wafer cleaning, the biggest challenge faced in the process of combining tank cleaning and single-wafer cleaning is: how to control and keep particles and contaminants from adhering to the surface of the silicon wafer from the moment the silicon wafer is taken out of the cleaning solution of the tank cleaning after the tank cleaning until it is transferred to the single-wafer cleaning module and sprayed with the cleaning solution onto the silicon wafer to perform the single-wafer cleaning process. In this process, if particles or contaminants adhere to the silicon wafer, it will be difficult to remove them during the subsequent single-wafer cleaning period, which will greatly affect the yield and quality of the product.

According to FIG. 1A of the present invention, after the silicon wafer 102 is taken out of the liquid, a thin liquid film 104 is maintained on the silicon wafer 102. Because the liquid film 104 is too thin, the particles 106 are forced to adhere to the silicon wafer 102, and it is difficult to remove the particles 106 in the subsequent cleaning process. In contrast, as shown in FIG. 1B, after the silicon wafer 102 is taken out of the liquid, a thicker liquid film 104 is maintained on the silicon wafer 102. Because the liquid film 104 is thick, the particles 106 are far away from the surface of the silicon wafer 102. Therefore, the possibility of the particles 106 adhering to the surface of the silicon wafer 102 is greatly reduced.

Referring to Figures 2 to 6, a schematic diagram of transferring a silicon wafer from a first tank to a second tank and then to a single-wafer cleaning module is disclosed.

Referring to FIG. 2A to FIG. 2F , an embodiment of the present invention is disclosed, in which a liquid film of a certain thickness is controlled and maintained on the surface of the silicon wafer from the moment the silicon wafer comes out of the liquid in the first tank until it is completely taken out of the first tank. As shown in FIG. 2A , after the silicon wafer 202 is tank-cleaned in the first tank 201 containing a liquid, such as an SPM solution, the liquid supply device is moved to a position above the first tank 201. The liquid supply device includes a first nozzle 203 and a second nozzle 205. Then the silicon wafer 202 is taken out of the first tank 201, as shown in FIG. 2B , before the silicon wafer 202 comes out of the liquid in the first tank 201, the first nozzle 203 is opened to spray the same liquid as in the first tank 201, such as an SPM solution. Since the first nozzle 203 has been opened to spray liquid, the moment the silicon wafer 202 comes out of the liquid in the first groove 201, the first nozzle 203 sprays liquid toward the silicon wafer 202 to maintain a certain thickness of liquid film on the silicon wafer 202, as shown in FIG2C. Since the liquid film on the silicon wafer 202 becomes thinner at the moment the silicon wafer 202 comes out of the liquid in the first groove 201, the first nozzle 203 is configured to spray liquid toward the silicon wafer 202 at the moment the silicon wafer 202 comes out of the liquid in the first groove 201, so that a certain thickness of liquid film is maintained on the silicon wafer 202. Here, the first nozzle 203 can delay spraying liquid onto the silicon wafer 202 until the silicon wafer 202 partially or completely comes out of the liquid in the first groove 201, as long as the thickness of the liquid film on the silicon wafer 202 is higher than a certain value, which will be described in detail in Figures 8A to 8C. The first nozzle 203 continues to spray liquid onto the silicon wafer 202 until the silicon wafer 202 is completely taken out of the first groove 201, as shown in Figure 2D. Then, the silicon wafer 202 rotates from the vertical surface to the inclined surface, and the liquid supply device also rotates therewith. As shown in Figure 2E, the first nozzle 203 continues to spray liquid onto the silicon wafer 202. The silicon wafer 202 rotates from the inclined plane to the horizontal plane, and the liquid supply device also rotates therewith. After the silicon wafer 202 rotates to the horizontal plane, the first nozzle 203 is closed and the spraying of liquid to the silicon wafer 202 is stopped. As shown in FIG. 2F , a liquid film 204 of a certain thickness is formed on the silicon wafer 202. The process of the silicon wafer 202 rotating from the vertical plane to the horizontal plane can be a continuous process with a certain rotation speed. The faster the rotation speed, the thicker the liquid film 204 on the silicon wafer 202. However, the maximum thickness of the liquid film on the silicon wafer is determined by the surface tension of the liquid film on the silicon wafer. Optionally, the silicon wafer 202 rotates to the inclined plane, and there is a pause before the silicon wafer 202 rotates to the horizontal plane, so as to control the thickness of the liquid film 204 on the silicon wafer 202. The longer the pause time, the thinner the liquid film 204 on the silicon wafer 202. It is best to maintain a liquid film of appropriate thickness on the silicon wafer 202, and the reason will be explained in detail in Figures 9A to 9C.

Referring to FIGS. 3A to 3E , a silicon wafer 202 having a certain thickness of a liquid film 204 is horizontally transferred to a position above a second tank 207 for tank cleaning. The second tank 207 contains a liquid, such as deionized water, and a liquid supply device is also moved to a position above the second tank 207. Then, the silicon wafer 202 rotates from a horizontal plane to an inclined plane, and finally to a vertical plane. The rotation process can be continuous. As shown in FIGS. 3B to 3C , in order to maintain a certain thickness of a liquid film on the silicon wafer, from the moment the silicon wafer 202 rotates, the second nozzle 205 is turned on to spray liquid onto the silicon wafer 202. The liquid sprayed by the second nozzle 205 is the same as the liquid in the second tank 207, such as deionized water. As shown in FIG3D , the second nozzle 205 continues to spray liquid onto the silicon wafer 202, and the silicon wafer 202 is placed in the second tank 207. As shown in FIG3E , after the silicon wafer 202 has been completely immersed in the liquid in the second tank 207, the second nozzle 205 is closed and the spraying of liquid is stopped. In another embodiment, after the silicon wafer 202 having a certain thickness of the liquid film 204 is horizontally transferred to a position above the second tank 207, the silicon wafer 202 is turned from the horizontal plane to the vertical plane, and then placed in the second tank 207 without opening the second nozzle 205.

Referring to FIGS. 4A to 4D , after the silicon wafer 202 is processed in the second groove 207, the third nozzle 208 moves to a position above the second groove 207, as shown in FIG. 4A . Then, the silicon wafer 202 is taken out of the second groove 207. As shown in FIG. 4B , before the silicon wafer 202 comes out of the liquid in the second groove 207, the third nozzle 208 is turned on to spray liquid, such as deionized water. As shown in FIG. 4C , because the third nozzle 208 has been turned on to spray liquid, the moment the silicon wafer 202 comes out of the liquid in the second groove 207, the third nozzle 208 sprays liquid to the silicon wafer 202 so as to maintain a certain thickness of liquid film on the silicon wafer 202. Since the liquid film on the silicon wafer 202 becomes thinner when the silicon wafer 202 comes out of the liquid in the second groove 207, the third nozzle 208 is configured to start spraying liquid to the silicon wafer 202 when the silicon wafer 202 comes out of the liquid in the second groove 207, so that a liquid film of a certain thickness is maintained on the silicon wafer 202. As shown in FIG. 4D, the third nozzle 208 continues to spray liquid to the silicon wafer 202, and the silicon wafer 202 is completely taken out from the second groove 207.

Referring to FIGS. 5A to 5H , the silicon wafer 202 is transferred to the support seat 502 of the flipping device and the silicon wafer 202 is held by the support seat 502. During this process, the third nozzle 208 continues to spray liquid onto the silicon wafer 202, as shown in FIGS. 5A to 5B . Then the support seat 502 descends, and the silicon wafer is held by the silicon wafer holder of the flipping device. The support seat 502 continues to descend and separates from the silicon wafer 202. As shown in FIG. 5C , the third nozzle 208 continues to spray liquid onto the silicon wafer 202. As shown in FIG5D , the flipping device causes the silicon wafer 202 to rotate from the vertical surface to the inclined surface and the third nozzle 208 continues to spray liquid onto the silicon wafer 202. As shown in FIG5E , the third nozzle 208 stops spraying liquid onto the silicon wafer 202 and is removed. As shown in FIG5F , the flipping device causes the silicon wafer 202 to rotate from the inclined surface to the horizontal surface and maintains a liquid film 504 with a maximum thickness on the silicon wafer 202. In order to control the thickness of the liquid film 504 on the silicon wafer 202, the silicon wafer 202 rotates to the inclined surface, and there is a pause before the silicon wafer 202 rotates to the horizontal surface. The thickness of the liquid film 504 on the silicon wafer 202 is determined by the pause time. The longer the pause time is, the thinner the thickness of the liquid film 504 on the silicon wafer 202 is. As shown in FIG. 5G to FIG. 5H , the process robot 506 takes the silicon wafer 202 from the flipping device and transfers the silicon wafer 202 to the single-wafer cleaning module 510. By controlling the transmission acceleration of the process robot 506, a certain thickness of the liquid film 504 can be maintained on the silicon wafer 202. The transmission acceleration of the process robot 506 can be controlled to ensure that the thickness of the liquid film 504 around the silicon wafer 202 is not greater than the maximum thickness of the liquid film maintained by the surface tension of the liquid. Therefore, during the process robot 506 transferring the silicon wafer 202, the liquid on the silicon wafer 202 will not fall from the periphery of the silicon wafer 202, and a certain thickness of liquid film 504 can be maintained on the silicon wafer 202 to reduce the possibility of particles in the liquid film 504 adhering to the surface of the silicon wafer 202. These will be explained in detail in Figures 8A to 8C.

After the silicon wafer 202 is transferred to the single-wafer cleaning module 510, the fourth nozzle 508 sprays liquid onto the silicon wafer 202 before the silicon wafer 202 rotates in the single-wafer cleaning module 510 to maintain a liquid film 504 of a certain thickness on the silicon wafer 202. In the single-wafer cleaning module 510, the silicon wafer 202 is subjected to a single-wafer cleaning and drying process.

Referring to FIGS. 6A to 6J , another embodiment of the present invention is disclosed, in which a silicon wafer 202 is transferred to a support seat 602 of a flipping device and the silicon wafer 202 is held by the support seat 602. As shown in FIGS. 6A to 6B , during this process, the third nozzle 208 continues to spray liquid onto the silicon wafer 202. Then the support seat 602 descends, and the silicon wafer is held by the silicon wafer holder of the flipping device. The support seat 602 continues to descend and separates from the silicon wafer 202. As shown in FIG. 6C , the third nozzle 208 continues to spray liquid onto the silicon wafer 202. As shown in FIG6D , the flipping device causes the silicon wafer 202 to turn from the vertical plane to the inclined plane and the third nozzle 208 continues to spray liquid onto the silicon wafer 202. As shown in FIG6E , the flipping device causes the silicon wafer 202 to turn from the inclined plane to the horizontal plane, and at the same time the third nozzle 208 continues to spray liquid onto the silicon wafer 202, so that a liquid film 604 of a certain thickness is formed on the silicon wafer 202. The process of the silicon wafer 202 turning from the vertical plane to the horizontal plane can be a continuous process. As shown in FIG6F , the third nozzle 208 then stops spraying liquid onto the silicon wafer 202 and is removed. As shown in FIG6G , the flipping device turns the silicon wafer 202 from the horizontal plane to the inclined plane, and there is a pause at the inclined plane to control the thickness of the liquid film 604 on the silicon wafer 202. The control of the tilt angle and the pause time can ensure that the liquid film 604 is neither too thin to cause particles to adhere to the silicon wafer 202, nor too thick to cause the liquid on the silicon wafer 202 to fall off during the transfer of the silicon wafer 202. As shown in FIG6H , the flipping device turns the silicon wafer 202 from the inclined plane to the horizontal plane. As shown in FIG6I to FIG6J , the process robot 606 takes the silicon wafer 202 from the flipping device and transfers it to the single-wafer cleaning module 610. By controlling the transmission acceleration of the process robot 606, a certain thickness of liquid film 604 can be maintained on the silicon wafer 202. The transmission acceleration of the process robot 606 can be controlled to ensure that the thickness of the liquid film 604 around the silicon wafer 202 is not greater than the maximum thickness of the liquid film that can be maintained by the surface tension of the liquid. Therefore, during the process robot 606 transmitting the silicon wafer 202, the liquid on the silicon wafer 202 will not fall from the periphery of the silicon wafer 202, and a certain thickness of liquid film 604 can be maintained on the silicon wafer 202 to reduce the possibility of particles in the liquid film 604 adhering to the surface of the silicon wafer 202.

After the silicon wafer 202 is transferred to the single-wafer cleaning module 610, the fourth nozzle 608 sprays liquid onto the silicon wafer 202 before the silicon wafer 202 rotates in the single-wafer cleaning module 610 to maintain a liquid film 604 of a certain thickness on the silicon wafer 202. The single-wafer cleaning and drying process is performed on the silicon wafer 202 in the single-wafer cleaning module 610.

Referring to FIG. 7A to FIG. 7B, another embodiment of controlling and maintaining a certain thickness of a liquid film on a silicon wafer according to the present invention is disclosed. As shown in FIG. 7A, after the silicon wafer 702 is tank-cleaned in the first tank 701 containing a liquid such as an SPM solution, the silicon wafer 702 is taken out of the first tank 701 and flipped from a vertical plane to a horizontal plane, so that a certain thickness of a liquid film 704 is maintained on the silicon wafer 702. Then, the silicon wafer 702 with a certain thickness of the liquid film 704 is transferred to a second tank 707 containing a liquid such as deionized water for tank cleaning. The silicon wafer 702 is flipped from a horizontal plane to a vertical plane and placed vertically in the second tank 707 for tank cleaning.

In all the above embodiments, although only one silicon wafer, one first groove, one second groove and one single-wafer cleaning module are shown to describe the mechanism of the present invention for controlling and maintaining a liquid film of a certain thickness on a silicon wafer, it should be recognized that multiple silicon wafers can be processed, and the number of silicon wafers, the number of first grooves, the number of second grooves and the number of single-wafer cleaning modules can be determined according to different process requirements.

Referring to Figures 8A to 8C, the relationship between the thickness of the liquid film on the silicon wafer and the size of the particles is revealed. The thickness of the liquid film on the silicon wafer is related to the diameter of the largest particle. In order to prevent particles from adhering to the silicon wafer, the thickness of the liquid film on the silicon wafer must not be less than the diameter of the largest particle. After satisfying this relationship, the largest particle is likely to be suspended in the liquid film, and the chance of adhering to the silicon wafer will be reduced. Since the largest particle may be suspended in the liquid film, other particles smaller than the largest particle are more likely to be suspended in the liquid film, further reducing the possibility of particles adhering to the silicon wafer. Figure 8A reveals that the thickness of the liquid film 804 on the silicon wafer 802 is greater than the diameter of the largest particle 806 in the liquid film 804. FIG8B reveals that the thickness of the liquid film 804 on the silicon wafer 802 is equal to the diameter of the largest particle 806 in the liquid film 804. FIG8C reveals that the thickness of the liquid film 804 on the silicon wafer 802 is less than the diameter of the largest particle 806 in the liquid film 804. Therefore, under the conditions of FIG8B and FIG8C, the largest particle 806 will contact the surface of the silicon wafer 802, and the chance of the largest particle 806 being attached to the surface of the silicon wafer 802 will be very high, which is not ideal.

The thickness of the liquid film on the silicon wafer is related to the transfer rate when the robot transfers the silicon wafer. As shown in FIG9A , the thickness of the liquid film 904 on the silicon wafer 902 is relatively thick. When the robot transfers the silicon wafer 902 with a thick liquid film 904, if the transfer acceleration of the robot is relatively large, the liquid film 904 may flow to the periphery of the silicon wafer 902, so that the thickness of the liquid film 904 around the silicon wafer 902 increases, as shown in FIG9C . If the thickness of the liquid film 904 around the silicon wafer 902 is greater than the maximum thickness of the liquid film that can be maintained by the surface tension of the liquid, then during the process of the robot transferring the silicon wafer 902, the liquid on the silicon wafer will drip from the periphery of the silicon wafer 902. As shown in FIG. 9B , the thickness of the liquid film 904 on the silicon wafer 902 is relatively thin, so during the period when the manipulator transfers the silicon wafer 902, as long as the thickness of the liquid film 904 around the silicon wafer 902 is not greater than the maximum thickness of the liquid film that can be maintained by the surface tension of the liquid, the transfer acceleration of the manipulator can be very large. Therefore, during the period when the manipulator transfers the silicon wafer 902, the liquid on the silicon wafer will not drip from the periphery of the silicon wafer 902, and a certain thickness of the liquid film 904 can be maintained on the silicon wafer 902, so as to reduce the possibility of particles in the liquid film 904 adhering to the surface of the silicon wafer 902.

In some embodiments, the second tank may not be used. The silicon wafer is tank-cleaned in the first tank, and then the silicon wafer is taken out of the first tank and transferred to the single-wafer cleaning module for cleaning and drying of the single-wafer. The contents disclosed in Figures 2 and 5 to 9 are also applicable here, so as to control and maintain a certain thickness of liquid film on the silicon wafer from the moment the silicon wafer comes out of the liquid in the first tank until it is transferred to the single-wafer cleaning module.

Referring to FIGS. 10 to 12 , an apparatus for cleaning semiconductor silicon wafers according to an embodiment of the present invention is disclosed. The apparatus 1000 includes: multiple loading ports 1010, a front-end robot 1020, a first flipping device 1030, a first silicon wafer transfer robot, a cleaning tank 1040, at least one first tank 1050, one or more second tanks 1060, a second silicon wafer transfer robot, a second flipping device 1070, a process robot 1080, one or more single-wafer cleaning modules 1090, a buffer chamber 1100, a chemical liquid supply system 1200, an electric control system 1300 and a controller. The controller is used to control multiple robots.

In one embodiment, a plurality of loading ports 1010 are arranged side by side at one end of the device 1000. To illustrate the layout of the device 1000 of the present invention, the plurality of loading ports 1010 can be considered to be arranged horizontally. The cleaning tank 1040, at least one first tank 1050 and one or more second tanks 1060 are located on one side of the device 1000. The arrangement of the cleaning tank 1040, at least one first tank 1050 and one or more second tanks 1060 is a longitudinal arrangement. One or more single-wafer cleaning modules 1090 are located on the other side of the device 1000 and are arranged opposite to the cleaning tank 1040, at least one first tank 1050 and one or more second tanks 1060. The one or more single-wafer cleaning modules 1090 are arranged in a longitudinal arrangement. There is a space between the one or more single-wafer cleaning modules 1090 and the cleaning tank 1040, at least one first tank 1050 and one or more second tanks 1060. The process robot 1080 is located in the space and can move longitudinally in the space. The chemical liquid supply system 1200 and the power control system 1300 are located at the other end of the device 1000 and opposite to the multiple loading ports 1010. The advantages of the layout of the device 1000 are as follows: (1) the lateral length or width of the device 1000 is shorter and the longitudinal length of the device 1000 is longer, which is more suitable for the requirements of semiconductor manufacturers; (2) the device 1000 can be expanded if necessary, such as increasing the number of single-wafer cleaning modules 1090 in the longitudinal direction, and/or increasing the number of first slots 1050 and the number of second slots 1060 in the longitudinal direction. In one embodiment, as shown in FIG. 12, the single-wafer cleaning modules 1090 are arranged in two layers. The single-wafer cleaning modules 1090 can be arranged in two or more stacked layers, and the number of single-wafer cleaning modules can be increased without increasing the floor space occupied by the device 1000. In one embodiment, the first flipping device 1030 is disposed adjacent to the cleaning tank 1040, and the second flipping device 1070 is disposed adjacent to the second tank 1060.

As shown in FIG. 13 , each loading port 1010 is configured to receive a wafer box 1301. The wafer box 1301 can carry multiple wafers 1302, such as 25 wafers. The front-end manipulator 1020 can move horizontally. The front-end manipulator 1020 takes out multiple wafers 1302 from the wafer box 1301 and transfers the multiple wafers 1302 to the first flipping device 1030.

As shown in FIG. 14A to FIG. 14D , the first flipping device 1030 includes a base 1031 and a support frame 1032. The support frame 1032 includes two opposite side walls and a bottom wall connected to the two opposite side walls. The bottom wall of the support frame 1032 is connected to the base 1031 via a rotating shaft 1033. The first driving device 1034 is configured to drive the support frame 1032 to rotate via the rotating shaft 1033. The first flipping device 1030 includes a silicon wafer holding device 1035, which is rotatably mounted on two opposite side walls of the support frame 1032 via two rotating shafts 1036. The second driving device 1037 is configured to drive any one of the two rotating shafts 1036 to rotate, thereby rotating the silicon wafer holding device 1035. The lifting device 1038 is connected to the third driving device. The third driving device is configured to drive the lifting device 1038 to move up and down.

As shown in FIG14A , the front-end manipulator 1020 takes out a plurality of silicon wafers 1302 from the silicon wafer box 1301 and transfers them horizontally to the silicon wafer holding device 1035 of the first flipping device 1030 . The silicon wafer holding device 1035 holds the plurality of silicon wafers 1302 horizontally. Then the second driving device 1037 drives any one of the two rotating shafts 1036 to rotate, so that the silicon wafer holding device 1035 rotates 90 degrees, thereby rotating the plurality of silicon wafers 1302 from the horizontal plane to the vertical plane. As shown in FIG14B , the silicon wafer holding device 1035 holds the plurality of silicon wafers 1302 vertically. As shown in FIG14C , the first driving device 1034 drives the support frame 1032 to rotate 90 degrees, which will facilitate the first silicon wafer transfer robot to take the multiple silicon wafers 1302 from the lifting device 1038 and place the multiple silicon wafers 1302 into at least one first slot 1050. Then, the third driving device drives the lifting device 1038 to move upward to support the multiple silicon wafers 1302. As shown in FIG14D , the multiple silicon wafers 1302 are separated from the silicon wafer holding device 1035 so that the first silicon wafer transfer robot can take the multiple silicon wafers 1302 from the lifting device 1038.

Optionally, after the multiple silicon wafers 1302 are horizontally transferred to the silicon wafer holding device 1035 of the first flipping device 1030, the first driving device 1034 drives the support frame 1032 to rotate 90 degrees. Then the second driving device 1037 drives any one of the two rotating shafts 1036 to rotate, so that the silicon wafer holding device 1035 rotates 90 degrees, so that the multiple silicon wafers 1302 held by the silicon wafer holding device 1035 rotate from the horizontal plane to the vertical plane. Then, the third driving device drives the lifting device 1038 to move upward to support the multiple silicon wafers 1302. The plurality of silicon wafers 1302 are separated from the silicon wafer holding device 1035 so that the first silicon wafer transfer robot can take the plurality of silicon wafers 1032 from the lifting device 1038.

The first silicon wafer transfer robot takes the plurality of silicon wafers 1302 from the lifting device 1038 of the first flipping device 1030 and transfers the plurality of silicon wafers 1302, for example, 6 or 7 silicon wafers each time, to at least one first tank 1050. The first silicon wafer transfer robot places the plurality of silicon wafers 1302 into at least one first tank 1050. The at least one first tank 1050 is configured to perform tank cleaning on the plurality of silicon wafers 1302. The at least one first tank 1050 contains a cleaning chemical solution for cleaning the plurality of silicon wafers 1302. The cleaning chemical solution in the at least one first tank 1050 may be an SPM solution, which is a mixture of sulfuric acid and hydrogen peroxide. The concentration ratio of sulfuric acid to hydrogen peroxide may be 3:1 to 50:1, which may be specifically selected according to different process requirements. The temperature of the SPM solution can be between 80°C and 150°C, and the temperature is adjustable.

After the multiple silicon wafers 1302 complete the process in at least one first tank 1050, the first silicon wafer transfer robot takes out the multiple silicon wafers 1302 from the at least one first tank 1050 and transfers them to one or more second tanks 1060. The first silicon wafer transfer robot places the multiple silicon wafers 1302 into the one or more second tanks 1060. The one or more second tanks 1060 are configured to perform tank cleaning on the multiple silicon wafers 1302. In one embodiment, two second tanks 1060 are included. The multiple silicon wafers 1302 are divided into two groups, and the two groups of silicon wafers 1302 are placed in the two second tanks 1060 respectively. The multiple silicon wafers 1302 are quickly discharged and cleaned in the two second tanks 1060. The cleaning liquid used for rapid discharge cleaning in the two second tanks 1060 may be deionized water. The temperature of the deionized water may be from room temperature to 90°C.

According to an embodiment of the present invention, at least one first tank 1050 contains HF solution, and at least one second tank 1060 contains H ₃ PO ₄ solution. Another second tank 1060 contains deionized water for rapid drain cleaning. The concentration of the HF solution can be 1:10 to 1:1000. The temperature of the HF solution can be set at about 25°C. The concentration of the H ₃ PO ₄ solution can be set at about 86%. The temperature of the H ₃ PO ₄ solution can be set at 150°C to 200°C. Before the H ₃ PO ₄ process, the HF solution can be used to remove native silicon oxide. The _{H 3} PO ₄ solution can be used to remove silicon nitride.

The method disclosed in FIG. 2 to FIG. 3 and FIG. 7 can be applied here to control and maintain a certain thickness of liquid film on the multiple silicon wafers 1302 from the moment the multiple silicon wafers 1302 come out of the cleaning chemical liquid in at least one first tank 1050 until they are placed in the cleaning liquid in one or more second tanks 1060.

The cleaning tank 1040 is configured to clean the gripping arm of the first silicon wafer transfer robot when the first silicon wafer transfer robot is idle. When the first silicon wafer transfer robot is idle, the first silicon wafer transfer robot moves to the cleaning tank 1040 and cleans in the cleaning tank 1040.

After the multiple silicon wafers 1302 have completed the process in the two second tanks 1060, the second silicon wafer transfer robot takes out a certain number of silicon wafers 1302 from the two second tanks 1060 each time, and then transfers the certain number of silicon wafers 1302 to the second flip device 1070. The number of silicon wafers 1302 taken out from the two second tanks 1060 each time can be equal to or less than the number of single-wafer cleaning modules 1090. In order to reduce the time that the silicon wafers 1302 are exposed to the air and prevent the silicon wafers 1302 from drying out after being taken out from the second tank 1060, preferably, one, two or less than ten silicon wafers are taken out from the second tank 1060 each time.

Referring to Figures 15 to 16, a second silicon wafer transfer robot according to an embodiment of the present invention is disclosed. The second silicon wafer transfer robot includes a pair of clamping arms 1501. Two clamping grooves 1502 are provided at one end of each clamping arm 1501 for clamping two silicon wafers when the second silicon wafer transfer robot is used to transfer silicon wafers. The other end of each clamping arm 1501 is movably connected to two nozzle devices 1503, so that the pair of clamping arms 1501 can be opened outward to pick up or release the silicon wafer 1302, or closed inward to clamp the silicon wafer 1302. The two nozzle devices 1503 are long strips and arranged horizontally side by side. Each nozzle device 1503 has a slit nozzle 1504 and at least one, for example, two liquid inlets 1505, and the liquid inlet 1505 is connected to the slit nozzle 1504 and is used to supply liquid to the slit nozzle 1504. When the second silicon wafer transfer robot is used to take out the silicon wafer 1302 from any second slot 1060 and transfer the silicon wafer 1302 to the second flipping device 1070, the nozzle device 1503 can be opened to spray liquid to the silicon wafer 1302 through the slit nozzle 1504 to control and maintain a liquid film with a certain thickness on the silicon wafer 1302, and the nozzle device 1503 can also be closed to stop spraying liquid. The flow rate of liquid supplied to the nozzle 1504 is adjustable according to the process requirements. For example, for a 300mm silicon wafer, the flow rate is between 51pm and 301pm. Different sizes of nozzles 1504 can also be set according to different process requirements. Usually, the width of the slit is between 1mm and 4mm, and the length is greater than the diameter of the silicon wafer. The number of nozzle devices 1503 matches the number of silicon wafers clamped by the clamping arm 1501, so one nozzle device 1503 corresponds to one silicon wafer 1302 and sprays liquid on it.

Referring to Figures 17 to 18, a second flipping device 1070 according to an embodiment of the present invention is disclosed. The second flipping device 1070 includes a receiving cavity 1071. The receiving cavity 1071 is roughly rectangular. A silicon wafer holder 1072 is disposed in the receiving cavity 1071. Specifically, the silicon wafer holder 1072 is movably mounted on a pair of side walls of the receiving cavity 1071. A first driving mechanism 1073 is connected to the silicon wafer holder 1072, and is used to drive the silicon wafer holder 1072 to rotate in the receiving cavity 1071. A support seat 1074 is fixed to the end of a support rod 1075. The end of the support rod 1075 extends into the receiving cavity 1071, so the support seat 1074 is disposed in the receiving cavity 1071. The other end of the support rod 1075 is connected to the second drive mechanism 1076 through a connector. The second drive mechanism 1076 is used to drive the support seat 1074 to move up and down. A window 1077 is provided on the side wall of the receiving cavity 1071. A door 1078 is provided in the receiving cavity 1071. The door 1078 is connected to the third drive mechanism 1079. The third drive mechanism 1079 is used to drive the door 1078 to move upward to close the window 1077, or to move downward to open the window 1077.

Referring to FIGS. 19 to 25 , an embodiment of the present invention is disclosed, in which the second silicon wafer transport robot takes out two silicon wafers 1302 from any second tank 1060. At the moment when the two silicon wafers 1302 come out of the cleaning liquid in the second tank 1060, the two nozzle devices 1503 are opened to spray the cleaning liquid 1900 onto the two silicon wafers 1302. The second driving mechanism 1076 drives the support seat 1074 to move upward, so that the support seat 1074 moves to the top of the receiving cavity 1071. The door 1078 closes the window 1077. The second silicon wafer transport robot transports the two silicon wafers 1302 to the support seat 1074. The second silicon wafer transfer robot places the two silicon wafers 1302 vertically on the support seat 1074. The support seat 1074 vertically holds the two silicon wafers 1302. Then the second drive mechanism 1076 drives the support seat 1074 to move downward, and the silicon wafer holder 1072 of the second flipping device 1070 vertically holds the two silicon wafers 1302. The second drive mechanism 1076 drives the support seat 1074 to continue to move downward, so that the support seat 1074 leaves the two silicon wafers 1302. The support seat 1074 can be located at the bottom of the receiving cavity 1071. From the moment the two silicon wafers 1302 come out of the cleaning liquid in the second tank 1060 until the moment the two silicon wafers 1302 rotate in the receiving chamber 1071, the two nozzle devices 1503 spray the cleaning liquid 1900 to the two silicon wafers 1302. The cleaning liquid in the receiving chamber 1071 can be discharged. The two nozzle devices 1503 are closed and the liquid spraying to the two silicon wafers 1302 is stopped, and the first driving mechanism 1073 drives the silicon wafer holder 1072 to rotate from the vertical plane to the horizontal plane. Therefore, the two silicon wafers 1302 rotate from the vertical plane to the horizontal plane together with the silicon wafer holder 1072. Next, the first driving mechanism 1073 drives the two silicon wafers 1302 to rotate from the horizontal plane to the inclined plane. There is a pause on the inclined plane, the purpose of which is to control the thickness of the liquid film on the silicon wafer 1302. Controlling the tilt angle and the pause time can ensure that the thickness of the liquid film is neither too thin to cause particles to adhere to the silicon wafer 1302 nor too thick to cause the liquid on the silicon wafer 1302 to fall off during the transmission process. The longer the pause time, the thinner the liquid film thickness on the silicon wafer 1302. The first driving mechanism 1073 then drives the two silicon wafers 1302 to rotate from the inclined plane to the horizontal plane. The third driving mechanism 1079 drives the door 1078 to move downward to open the window 1077. The process robot 1080 takes two silicon wafers 1302 from the receiving chamber 1071 and transfers the two silicon wafers 1302 with a certain thickness of liquid film to the single-wafer cleaning module 1090 for single-wafer cleaning and drying process processing.

Referring to FIGS. 26 to 30 , another embodiment of the present invention is disclosed, in which the second silicon wafer transfer robot takes a silicon wafer 1302 from any second tank 1060. At the moment when the silicon wafer 1302 comes out of the cleaning liquid in the second tank 1060, a nozzle device 1503 is opened to spray the cleaning liquid 1900 toward the silicon wafer 1302. The second driving mechanism 1076 drives the support seat 1074 to move upward, so that the support seat 1074 moves to the top of the receiving cavity 1071. The second silicon wafer transfer robot transfers a silicon wafer 1302 to the support seat 1074. The second silicon wafer transfer robot places a silicon wafer 1302 vertically on the support seat 1074. The support seat 1074 vertically holds a silicon wafer 1302. Then the second driving mechanism 1076 drives the support seat 1074 to move downward, and the silicon wafer holder 1072 of the second flipping device 1070 vertically holds a silicon wafer 1302. The second driving mechanism 1076 drives the support seat 1074 to continue to move downward, so that the support seat 1074 leaves the silicon wafer 1302. The support seat 1074 can be located at the bottom of the receiving cavity 1071. From the moment the silicon wafer 1302 comes out of the cleaning liquid in the second tank 1060 until the silicon wafer 1302 is held vertically by the silicon wafer holder 1072, a nozzle device 1503 always sprays the cleaning liquid 1900 onto the silicon wafer 1302. The silicon wafer 1302 is driven by the first drive mechanism 1073 to rotate from the vertical surface to the inclined surface, and the nozzle device 1503 continues to spray the cleaning liquid 1900 onto the silicon wafer 1302. The nozzle device 1503 can move back and forth above the silicon wafer 1302 and spray the cleaning liquid 1900 onto the silicon wafer 1302. The first drive mechanism 1073 drives the silicon wafer 1302 to rotate from the inclined plane to the horizontal plane, and the nozzle device 1503 still moves back and forth above the silicon wafer 1302 and sprays the cleaning liquid 1900 onto the silicon wafer 1302. The liquid 1900 in the receiving chamber 1071 can be discharged. The rotation process of the silicon wafer 1302 from the vertical plane to the horizontal plane can be continuous. The nozzle device 1503 is closed to stop spraying the cleaning liquid onto the silicon wafer 1302. The third drive mechanism 1079 drives the door 1078 to move downward to open the window 1077. The process robot 1080 horizontally removes a silicon wafer 1302 from the receiving chamber 1071. Then the process robot 1080 turns from the horizontal plane to the inclined plane, so the silicon wafer 1302 also turns from the horizontal plane to the inclined plane. There is a pause on the inclined plane, the purpose of which is to control the thickness of the liquid film on the silicon wafer. Controlling the tilt angle and the pause time can ensure that the thickness of the liquid film is neither too thin to cause particles to adhere to the silicon wafer 1302 nor too thick to cause the liquid on the silicon wafer 1302 to fall off during the transmission process. The longer the pause time, the thinner the thickness of the liquid film on the silicon wafer 1302. Then the process robot 1080 turns from the inclined plane to the horizontal plane, so the silicon wafer 1302 also turns from the inclined plane to the horizontal plane. The process robot 1080 transfers a silicon wafer 1302 with a liquid film of a certain thickness to the single-wafer cleaning module 1090 for single-wafer cleaning and drying process processing.

The method disclosed in FIGS. 4 to 6 can be applied here to control and maintain a certain thickness of liquid film on the one or more silicon wafers 1032 from the moment when the one or more silicon wafers 1302 come out of the cleaning liquid in the one or more second tanks 1060 until the one or more silicon wafers 1302 are transferred to the one or more single-wafer cleaning modules 1090.

Take a silicon wafer 1032 and a single-wafer cleaning module 1090 as an example. The single-wafer cleaning module 1090 includes a chuck. The process robot 1080 places a silicon wafer 1302 with a liquid film of a certain thickness on the chuck. After placing the silicon wafer 1302 with a liquid film of a certain thickness on the chuck, before the silicon wafer 1302 rotates in the single-wafer cleaning module, the nozzle sprays a liquid such as deionized water to the silicon wafer 1302 to maintain a liquid film of a certain thickness on the silicon wafer 1302. Then the chuck rotates in the single-wafer cleaning module 1090, and the silicon wafer 1302 rotates therewith. A chemical solution is applied to the silicon wafer 1302 to clean the silicon wafer 1302, and then deionized water is applied to the silicon wafer 1302. The flow rate of deionized water can be adjusted within the range of 1.2-2.31pm, preferably 1.81pm. The temperature of deionized water can be set at about 25°C. Then the silicon wafer 1302 is dried. The chemical solution applied to the silicon wafer 1302 can be, for example, DHF, SC1, DIO ₃ and other solutions. The flow rate of DHF can be adjusted within the range of 1.2-2.31pm, preferably 1.81pm. The temperature of DHF can be set at about 25°C. The concentration of DHF can be adjusted within the range of 1:10 to 1:1000. The flow rate of SC1 can be adjusted within the range of 1.2-2.31pm, preferably 1.81pm. The temperature of SC1 can be set at about 25°C to 50°C. The concentration of SC1 (NH ₄ OH:H ₂ O ₂ :H ₂ O) can be adjusted within the range of 1:1:5 to 1:2:100. The method of drying the silicon wafer 1302 includes: rotating the chuck at a speed of 1900 rpm and spraying nitrogen on the silicon wafer. The flow rate of the nitrogen can be adjusted within the range of 3.5-5.51pm, preferably 51pm. The temperature of the nitrogen can be set at about 25°C.

After the silicon wafer 1302 has completed the drying process in the single-wafer cleaning module 1090, the process robot 1080 takes out the silicon wafer 1302 from the single-wafer cleaning module 1090 and transfers the silicon wafer 1302 to the buffer chamber 1100. The front-end robot 1020 takes out the silicon wafer 1302 from the buffer chamber 1100 and transfers the silicon wafer 1302 to the silicon wafer box at the loading port 1010.

In some embodiments, the cleaning liquid is sprayed onto the one or more silicon wafers from the moment the one or more silicon wafers emerge from the cleaning chemical solution in the first tank until the one or more silicon wafers are immersed in the cleaning solution in the one or more second tanks. The cleaning liquid is sprayed onto the one or more silicon wafers from the moment the one or more silicon wafers emerge from the cleaning solution in the one or more second tanks until the one or more silicon wafers are transferred to one or more single-wafer cleaning modules.

In some embodiments, the cleaning liquid is sprayed onto the one or more silicon wafers from the moment the one or more silicon wafers emerge from the cleaning chemical liquid in the first tank until the one or more silicon wafers are immersed in the cleaning liquid in the one or more second tanks. The one or more silicon wafers are then taken out of the cleaning liquid in the one or more second tanks and rotated from a vertical plane to a horizontal plane. The one or more silicon wafers are then horizontally transferred to one or more single-wafer cleaning modules.

In some embodiments, one or more silicon wafers are taken out of the cleaning chemical solution in the first tank and turned from a vertical plane to a horizontal plane. The one or more silicon wafers are then transferred horizontally to one or more second tanks. The one or more silicon wafers are turned from a horizontal plane to a vertical plane and placed in the cleaning solution in the second tank. From the moment the one or more silicon wafers come out of the cleaning solution in the one or more second tanks until the one or more silicon wafers are transferred to one or more single-wafer cleaning modules, the cleaning solution is always sprayed on the one or more silicon wafers.

In some embodiments, one or more silicon wafers are taken out from the cleaning chemical solution in the first tank and turned from a vertical plane to a horizontal plane. The one or more silicon wafers are then transferred horizontally to one or more second tanks. The one or more silicon wafers are turned from a horizontal plane to a vertical plane and placed in the cleaning solution in the second tank. The one or more silicon wafers are taken out from the cleaning solution in one or more second tanks and turned from a vertical plane to a horizontal plane. The one or more silicon wafers are then transferred horizontally to one or more single-wafer cleaning modules.

In some embodiments, the one or more second tanks may be absent. One or more silicon wafers are transferred to at least one tank containing a cleaning solution for tank cleaning. Then the one or more silicon wafers are taken out of the cleaning solution in the at least one tank and transferred to one or more single-wafer cleaning modules for single-wafer cleaning and drying processes. The method disclosed in FIG. 2, FIG. 5 to FIG. 9, and FIG. 10 to FIG. 30 can be applied here, from the moment the one or more silicon wafers come out of the cleaning solution in at least one tank until the one or more silicon wafers are transferred to the single-wafer cleaning module, a certain thickness of liquid film is controlled and maintained on the one or more silicon wafers.

The controller is used to control the manipulator, the nozzle and the silicon wafer holder, from the moment when one or more silicon wafers come out of the cleaning chemical liquid in at least one first tank until the one or more silicon wafers are immersed in the cleaning liquid in one or more second tanks, and/or from the moment when one or more silicon wafers come out of the cleaning liquid in one or more second tanks until the one or more silicon wafers are transferred to one or more single-wafer cleaning modules, to maintain a certain thickness of liquid film on the one or more silicon wafers.

In summary, through the above implementation methods and related diagrams, the relevant technologies have been specifically and detailedly disclosed, so that technical personnel in this field can implement them accordingly. The above-mentioned embodiments are only used to illustrate the present invention, not to limit the present invention. The scope of rights of the present invention should be defined by the scope of the patent application of the present invention. As for the change of the number of components described in this article or the replacement of equivalent components, etc., they should still fall within the scope of rights of the present invention.

1000: Device for cleaning semiconductor silicon wafers

1010: Loading port

1020: Front-end robot

1030: First flipping device

1040: Cleaning tank

1050: First slot

1060: Second slot

1070: Second flipping device

1080: Process robot

1090: Single chip cleaning module

1100: Buffer room

1200: Chemical liquid supply system

1300: Power control system

Claims (44)

A method for cleaning semiconductor silicon wafers comprises the following steps: transferring one or more silicon wafers to at least one first tank and one or more second tanks in sequence to perform a tank cleaning process, wherein the first tank contains a chemical solution and the second tank contains a cleaning solution; taking the one or more silicon wafers out of the cleaning solution in the one or more second tanks, and transferring the one or more silicon wafers to a single-wafer cleaning module to perform a single-wafer cleaning and drying process; wherein, from the moment the one or more silicon wafers come out of the chemical solution in the at least one first tank until the one or more silicon wafers are dried, One or more silicon wafers are immersed in the cleaning liquid in the one or more second tanks, and/or from the moment when the one or more silicon wafers come out of the cleaning liquid in the one or more second tanks until the one or more silicon wafers are transferred to one or more single-wafer cleaning modules, a liquid film of a certain thickness is controlled and maintained on the one or more silicon wafers, and the thickness of the liquid film on the one or more silicon wafers is determined by the diameter of the largest particle in the liquid film, the transmission acceleration of the manipulator that transmits the one or more silicon wafers, and the maximum thickness of the liquid film maintained by the surface tension of the liquid on the one or more silicon wafers. According to the method for cleaning semiconductor silicon wafers as described in claim 1, the thickness of the liquid film on the one or more silicon wafers is not less than the diameter of the largest particle in the liquid film. According to the method for cleaning semiconductor silicon wafers as described in claim 1, the transmission acceleration of the robot is controlled so that the thickness of the liquid film on the one or more silicon wafers is not greater than the maximum thickness of the liquid film maintained by the surface tension of the liquid. The method for cleaning semiconductor silicon wafers according to claim 1 further comprises: spraying cleaning liquid onto the one or more silicon wafers from the moment when the one or more silicon wafers come out of the chemical liquid in the at least one first tank until the one or more silicon wafers are immersed in the cleaning liquid in the one or more second tanks; spraying liquid onto the one or more silicon wafers from the moment when the one or more silicon wafers come out of the cleaning liquid in the one or more second tanks until the one or more silicon wafers are transferred to one or more single-wafer cleaning modules. The method for cleaning semiconductor silicon wafers according to claim 1 further comprises: spraying liquid onto the one or more silicon wafers from the moment the one or more silicon wafers come out of the chemical solution in the at least one first tank until the one or more silicon wafers are immersed in the cleaning solution in the one or more second tanks; taking the one or more silicon wafers out of the cleaning solution in the one or more second tanks and rotating them from a vertical plane to a horizontal plane, and then transferring the one or more silicon wafers horizontally to one or more single-wafer cleaning modules. The method for cleaning semiconductor silicon wafers according to claim 1 further comprises: taking out one or more silicon wafers from the chemical solution in the at least one first tank and rotating them from a vertical plane to a horizontal plane; transferring the one or more silicon wafers horizontally to one or more second tanks; rotating the one or more silicon wafers from a horizontal plane to a vertical plane and placing them in the cleaning solution in the one or more second tanks; spraying liquid on the one or more silicon wafers from the moment the one or more silicon wafers come out of the cleaning solution in the one or more second tanks until the one or more silicon wafers are transferred to one or more single-wafer cleaning modules. The method for cleaning semiconductor silicon wafers according to claim 1 further comprises: taking out one or more silicon wafers from the chemical solution in the at least one first tank and rotating them from a vertical plane to a horizontal plane; transferring one or more silicon wafers horizontally to one or more second tanks; rotating one or more silicon wafers from a horizontal plane to a vertical plane and placing them in the cleaning solution in the one or more second tanks; taking out one or more silicon wafers from the cleaning solution in the one or more second tanks and rotating them from a vertical plane to a horizontal plane; and then transferring one or more silicon wafers horizontally to one or more single-wafer cleaning modules. The method for cleaning semiconductor silicon wafers according to claim 1 further comprises: transferring one or more silicon wafers to a single-wafer cleaning module; spraying a cleaning liquid onto the one or more silicon wafers before the one or more silicon wafers rotate in the one or more single-wafer cleaning modules. A method for cleaning semiconductor silicon wafers according to claim 1, wherein the number of silicon wafers taken out from the one or more second tanks each time is equal to or less than the number of single-wafer cleaning modules. According to the method for cleaning semiconductor silicon wafers as described in claim 1, the number of silicon wafers taken out from the one or more second tanks each time is one, two or less than ten. According to the method for cleaning semiconductor silicon wafers described in claim 1, the chemical liquid in at least one first tank is an SPM solution, the SPM solution is a mixture of sulfuric acid and hydrogen peroxide, and the temperature of the SPM solution is between 80°C and 150°C. According to the method for cleaning semiconductor silicon wafers described in claim 1, the chemical liquid in at least one first tank is an SPM solution, the SPM solution is a mixture of sulfuric acid and hydrogen peroxide, and the concentration ratio of sulfuric acid to hydrogen peroxide in the SPM solution is 3:1 to 50:1. According to the method for cleaning semiconductor silicon wafers as described in claim 1, the one or more silicon wafers are rapidly drained and cleaned in one or more second tanks. According to the method for cleaning semiconductor silicon wafers as described in claim 13, the solution used for rapid drain cleaning is deionized water. According to the method for cleaning semiconductor silicon wafers as described in claim 1, the number of the second tanks is at least two, the chemical liquid in at least one first tank is HF solution, the solution in at least one second tank is _H3PO4 solution, _and the solution in another second tank is deionized water for rapid drain cleaning. The method for cleaning a semiconductor silicon wafer according to claim 15, wherein the temperature of the H ₃ PO ₄ solution is 150° C. to 200° C. A method for cleaning semiconductor silicon wafers comprises the following steps: transferring one or more silicon wafers to at least one tank to perform a tank cleaning process, wherein the tank contains a cleaning solution; taking out the one or more silicon wafers from the at least one tank and transferring the one or more silicon wafers to one or more single-wafer cleaning modules to perform a single-wafer cleaning and drying process; wherein the one or more silicon wafers are transferred from the one or more silicon wafers to the single-wafer cleaning modules to perform a single-wafer cleaning and drying process. From the moment when the cleaning solution in one tank comes out until it is transferred to one or more single-wafer cleaning modules, a certain thickness of liquid film is controlled and maintained on the one or more silicon wafers. The thickness of the liquid film on the one or more silicon wafers is determined by the diameter of the largest particle in the liquid film, the transmission acceleration of the robot that transmits the one or more silicon wafers, and the maximum thickness of the liquid film maintained by the surface tension of the liquid on the one or more silicon wafers. According to the method for cleaning semiconductor silicon wafers as described in claim 17, the thickness of the liquid film on the one or more silicon wafers is not less than the diameter of the largest particle in the liquid film. According to the method for cleaning semiconductor silicon wafers as described in claim 17, the transmission acceleration of the robot is controlled so that the thickness of the liquid film on the one or more silicon wafers is not greater than the maximum thickness of the liquid film maintained by the surface tension of the liquid. A device for cleaning semiconductor silicon wafers, comprising: at least one first tank, the first tank containing chemical liquid, configured to perform a tank cleaning process; one or more second tanks, the second tank containing cleaning liquid, configured to perform a tank cleaning process; one or more single-wafer cleaning modules, configured to perform a cleaning and drying process of a single silicon wafer; multiple manipulators, configured to transfer one or more silicon wafers; a controller, configured to control the multiple manipulators to sequentially transfer one or more silicon wafers to at least one first tank, one or more second tanks, and then to one or more single-wafer cleaning modules; wherein the controller is configured to transfer one or more silicon wafers from the one or more silicon wafers to the one or more second tanks; A liquid film of a certain thickness is maintained on the one or more silicon wafers from the moment when the one or more silicon wafers come out of the chemical liquid in the one or more first tanks until the one or more silicon wafers are immersed in the cleaning liquid in the one or more second tanks, and/or from the moment when the one or more silicon wafers come out of the cleaning liquid in the one or more second tanks until the one or more silicon wafers are transferred to one or more single-wafer cleaning modules, and the controller is configured to determine the thickness of the liquid film on the one or more silicon wafers according to the diameter of the largest particle in the liquid film, the transmission acceleration of the manipulator that transmits the one or more silicon wafers, and the maximum thickness of the liquid film maintained by the surface tension of the liquid on the one or more silicon wafers. According to claim 20, the device for cleaning semiconductor silicon wafers, wherein the thickness of the liquid film on the one or more silicon wafers is not less than the diameter of the largest particle in the liquid film. According to the device for cleaning semiconductor silicon wafers as described in claim 20, the transmission acceleration of the robot is controlled so that the thickness of the liquid film on the one or more silicon wafers is not greater than the maximum thickness of the liquid film maintained by the surface tension of the liquid. The device for cleaning semiconductor silicon wafers according to claim 20 further comprises a liquid supply device having a first nozzle and a second nozzle; wherein, from the moment when the one or more silicon wafers come out of the chemical liquid in the at least one first tank until the one or more silicon wafers are completely taken out of the at least one first tank and rotated from a vertical plane to a horizontal plane, during this process, the first nozzle sprays liquid to the one or more silicon wafers. body; when the one or more silicon wafers are rotated to the horizontal plane so as to be horizontally transferred to the one or more second tanks, the first nozzle stops spraying liquid; wherein, from the moment when the one or more silicon wafers start to rotate from the horizontal plane above the one or more second tanks until the one or more silicon wafers are vertically immersed in the cleaning liquid in the one or more second tanks, during this process, the second nozzle sprays liquid to the one or more silicon wafers. The device for cleaning semiconductor silicon wafers according to claim 20 further comprises: a first flipping device configured to rotate one or more silicon wafers from a horizontal plane to a vertical plane for vertical transfer to at least one first tank; a second flipping device configured to rotate one or more silicon wafers from a vertical plane to a horizontal plane for horizontal transfer to one or more single-wafer cleaning modules. According to claim 24, the device for cleaning semiconductor silicon wafers, wherein the second flipping device comprises: a receiving cavity; a silicon wafer holder, the silicon wafer holder is arranged in the receiving cavity; a first driving mechanism, used to drive the silicon wafer holder to rotate in the receiving cavity; a support rod, one end of the support rod extends into the receiving cavity; a support seat, fixed to one end of the support rod; a second driving mechanism, driving the support seat to rise and fall through the support rod; a window, the window is arranged on the receiving cavity; a door, the door is arranged in the receiving cavity; a third driving mechanism, used to drive the door to move upward to close the window or move downward to open the window. According to claim 24, the device for cleaning semiconductor silicon wafers, wherein the multiple manipulators further include: a first silicon wafer transfer manipulator, configured to take one or more silicon wafers and transfer the one or more silicon wafers to at least one first slot or one or more second slots; a second silicon wafer transfer manipulator, configured to take a certain number of silicon wafers from one or more second slots each time and transfer them to a second flipping device; a process manipulator, configured to take a certain number of silicon wafers from the second flipping device and transfer them to a single-wafer cleaning module corresponding to the number. According to the device for cleaning semiconductor silicon wafers as described in claim 26, the second silicon wafer transfer robot includes a pair of clamping arms, and each clamping arm has a plurality of clamping grooves at one end for clamping multiple silicon wafers. The device for cleaning semiconductor silicon wafers according to claim 26 further comprises one or more nozzle devices, wherein each nozzle device is in an elongated shape and has a slit-shaped nozzle and at least one liquid inlet, and the liquid inlet is connected to the slit-shaped nozzle for supplying liquid. According to the device for cleaning semiconductor silicon wafers as described in claim 28, the number of the nozzle devices matches the number of silicon wafers gripped by the second silicon wafer transfer robot, and one nozzle device corresponds to one silicon wafer and sprays liquid onto the silicon wafer. According to the device for cleaning semiconductor silicon wafers as described in claim 28, the nozzle device can move back and forth above the silicon wafer and spray liquid onto the silicon wafer clamped by the second flipping device. According to the device for cleaning semiconductor silicon wafers as described in claim 26, the process robot can be turned from a horizontal plane to an inclined plane and then to a horizontal plane. An apparatus for cleaning semiconductor silicon wafers according to claim 26, wherein the number of silicon wafers taken out from one or more second tanks each time is equal to or less than the number of single-wafer cleaning modules. The device for cleaning semiconductor silicon wafers according to claim 26 further includes a cleaning tank for cleaning the first silicon wafer transfer robot when the first silicon wafer transfer robot is idle. The device for cleaning semiconductor silicon wafers according to claim 26 further comprises: at least one loading port; at least one silicon wafer box located at the at least one loading port; a buffer chamber, wherein the process robot takes out the silicon wafers from the single-wafer cleaning module and places them into the buffer chamber; a front-end robot, wherein the front-end robot takes out one or more silicon wafers from at least one silicon wafer box and transfers them to the first flipping device, and the front-end robot takes out a certain number of silicon wafers from the buffer chamber and transfers them to at least one silicon wafer box. The device for cleaning semiconductor silicon wafers according to claim 20, wherein the one or more silicon wafers are transferred to one or more single-wafer cleaning modules, and liquid is sprayed on the one or more silicon wafers before the one or more silicon wafers are rotated in the one or more single-wafer cleaning modules. According to the device for cleaning semiconductor silicon wafers as described in claim 20, the chemical liquid in at least one first tank is an SPM solution, the SPM solution is a mixture of sulfuric acid and hydrogen peroxide, and the temperature of the SPM solution is between 80°C and 150°C. According to the device for cleaning semiconductor silicon wafers as described in claim 20, the chemical liquid in at least one first tank is an SPM solution, the SPM solution is a mixture of sulfuric acid and hydrogen peroxide, and the concentration ratio of sulfuric acid to hydrogen peroxide in the SPM solution is 3:1 to 50:1. According to claim 20, the device for cleaning semiconductor silicon wafers, wherein the one or more silicon wafers are rapidly drained and cleaned in one or more second tanks. According to the device for cleaning semiconductor silicon wafers as described in claim 38, the cleaning liquid used for rapid discharge cleaning is deionized water. According to the device for cleaning semiconductor silicon wafers as described in claim 20, the number of the second tanks is at least two, the chemical liquid in at least one first tank is HF solution, the cleaning liquid in at least one second tank is _H3PO4 solution, _and the cleaning liquid in another second tank is deionized water for rapid drain cleaning. The apparatus for cleaning semiconductor silicon wafers according to claim 40, wherein the temperature of the H ₃ PO ₄ solution is between 150°C and 200°C. A device for cleaning semiconductor silicon wafers, comprising: a plurality of loading ports; at least one first tank, the first tank containing chemical liquid, configured to perform a tank cleaning process; one or more second tanks, the second tank containing cleaning liquid, configured to perform a tank cleaning process; one or more single-wafer cleaning modules, configured to perform a cleaning and drying process of a single silicon wafer; wherein the plurality of loading ports are arranged horizontally, the at least one first tank and the one or more second tanks are arranged vertically on one side, and the one or more single-wafer cleaning modules are arranged vertically on the other side and opposite to the at least one first tank and the one or more second tanks; a controller, configured to control a plurality of manipulators to sequentially transfer one or more silicon wafers to the at least one first tank, the one or more second tanks, and then to the One or more single-wafer cleaning modules, wherein the controller is configured to maintain a certain thickness of liquid film on the one or more silicon wafers from the moment when the one or more silicon wafers come out of the chemical liquid in the at least one first tank until the one or more silicon wafers are immersed in the cleaning liquid in the one or more second tanks, and/or from the moment when the one or more silicon wafers come out of the cleaning liquid in the one or more second tanks until the one or more silicon wafers are transferred to the one or more single-wafer cleaning modules, and the controller is configured to determine the thickness of the liquid film on the one or more silicon wafers according to the diameter of the largest particle in the liquid film, the transmission acceleration of the manipulator that transmits the one or more silicon wafers, and the maximum thickness of the liquid film maintained by the surface tension of the liquid on the one or more silicon wafers. According to claim 42, a semiconductor silicon wafer cleaning device is provided, wherein a space is formed between the one or more single-wafer cleaning modules and the at least one first tank and the one or more second tanks, and a process robot is provided in the space. A device for cleaning semiconductor silicon wafers, comprising: at least one tank, the tank containing cleaning solution, configured to perform a tank cleaning process; one or more single-wafer cleaning modules, configured to perform a cleaning and drying process of a single silicon wafer; one or more manipulators, configured to transfer one or more silicon wafers to the at least one tank and the one or more single-wafer cleaning modules; a controller, configured to control the one or more manipulators; wherein the controller is configured to transfer one or more silicon wafers to the at least one tank and the one or more single-wafer cleaning modules; A liquid film of a certain thickness is maintained on the one or more silicon wafers from the moment when the one or more silicon wafers come out of the cleaning solution in the at least one tank until they are transferred to one or more single-wafer cleaning modules, and the controller is configured to determine the thickness of the liquid film on the one or more silicon wafers according to the diameter of the largest particle in the liquid film, the transmission acceleration of the manipulator that transmits the one or more silicon wafers, and the maximum thickness of the liquid film maintained by the surface tension of the liquid on the one or more silicon wafers.

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