A method and system for cleaning a silicon wafer

Abstract

This application provides a silicon wafer cleaning method and system. The silicon wafer cleaning method involves placing a basket containing silicon wafers in a cleaning tank for cleaning, and during or after cleaning, changing the basket from a first placement state to a second placement state. This process of changing the basket from the first to the second placement state during cleaning in the tank facilitates comprehensive cleaning of the silicon wafers in the basket and makes subsequent lifting in the second placement state easier. This effectively avoids incomplete drainage and cross-contamination of silicon wafers during tank cleaning, thereby improving the problem of watermark defects in silicon wafer products.

Description

[0001] This application claims priority to Chinese Patent Application No. 202420829329.8, filed on April 19, 2024, entitled “A Flower Basket and Cleaning Equipment”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of photovoltaic production technology, and in particular to a silicon wafer cleaning method and cleaning system. Background Technology

[0003] In the production of solar cells, silicon wafers and solar cells frequently need to be transferred between different tank-type cleaning equipment to achieve surface micro-processing and cleaning. Current technologies typically use baskets for centralized loading and transfer to improve production efficiency.

[0004] During the cleaning of silicon wafers, solar cells, etc., the baskets containing the silicon wafers, solar cells, etc. need to be circulated in the cleaning tank. If the placement of the baskets is unstable or improper during circulation, it can easily lead to problems such as inadequate cleaning of the silicon wafers in the baskets and poor product watermarks. Summary of the Invention

[0005] The technical problem to be solved by this application is to provide a silicon wafer cleaning method and cleaning system to solve the problem that the existing method of cleaning silicon wafers by loading them in baskets is prone to inadequate cleaning of the silicon wafers in the baskets and poor product watermarks.

[0006] To solve the above problems, this application provides the following technical solution:

[0007] This application proposes a silicon wafer cleaning method, comprising:

[0008] The basket containing the silicon wafers is placed in the cleaning tank for cleaning;

[0009] During or after the cleaning process, the flower basket is changed from the first placement state to the second placement state.

[0010] Optionally, in the method, the flower basket is placed inside or outside the cleaning tank, changing from the first placement state to the second placement state.

[0011] Optionally, in the method, the flower basket is placed in a liquid environment and / or a nitrogen environment, changing from the first placement state to the second placement state.

[0012] Optionally, in the method, the basket is loaded with at least two layers of silicon wafers placed along a first direction;

[0013] The transition from the first placement state to the second placement state includes:

[0014] The flower basket is flipped over, changing its orientation from the first direction to the second direction.

[0015] Optionally, in the method, the flower baskets are configured as at least two and arranged along a first direction;

[0016] Changing the flower basket from the first placement state to the second placement state includes:

[0017] The arrangement of the flower baskets is changed from being placed along the first direction to being placed along the second direction.

[0018] Optionally, at least two flower baskets are provided, and the method includes the following steps before changing the flower baskets from the first placement state to the second placement state:

[0019] Adjust the spacing between adjacent flower baskets so that there is a preset spacing between adjacent flower baskets along the second direction.

[0020] Optionally, in the method, the spacing between adjacent flower baskets is adjusted to a preset spacing within the cleaning tank; or, the flower baskets are transferred outside the cleaning tank, the spacing between adjacent flower baskets is adjusted to a preset spacing outside the cleaning tank, and then placed into another cleaning tank.

[0021] Alternatively, the flower baskets can be moved out of the washing tank one by one, and then placed into another washing tank according to the preset spacing.

[0022] Optionally, the method further includes: after cleaning, drying the flower basket in the second placement state.

[0023] This application also proposes a silicon wafer cleaning system, which includes at least one cleaning tank and a flipping mechanism;

[0024] The cleaning tank is used to hold a basket containing silicon wafers;

[0025] The flipping mechanism is used to change the flower basket from a first placement state to a second placement state during or after the cleaning process.

[0026] Optionally, in the cleaning system, the flipping mechanism includes a flower basket seat and a drive unit. The flower basket seat is disposed in the cleaning tank to support the flower basket, and the drive unit drives the flower basket seat to rotate so that the flower basket changes from the first placement state to the second placement state.

[0027] Optionally, in the cleaning system, the flipping mechanism is located outside the cleaning tank and is used to transfer the flower basket and change the flower basket from the first placement state to the second placement state.

[0028] Optionally, the cleaning system further includes a transfer mechanism for transferring the flower baskets within the cleaning tank.

[0029] Optionally, in the cleaning system, the transfer mechanism includes a first transfer member and two second transfer members, with the two second transfer members respectively disposed on both sides of the first transfer member.

[0030] Optionally, the cleaning system further includes a nitrogen purging mechanism, which is used to blow nitrogen into and / or outside the cleaning tank.

[0031] Optionally, the cleaning system further includes a drying device connected to the cleaning tank and used to dry the flower basket in the second placement state.

[0032] Compared with the prior art, this application has the following advantages:

[0033] The silicon wafer cleaning method of this application involves placing a basket containing silicon wafers in a cleaning tank for cleaning, and changing the basket from a first placement state to a second placement state during or after cleaning. The method of flipping the basket from the first to the second placement state during cleaning in the tank facilitates comprehensive cleaning of the silicon wafers in the basket and makes subsequent lifting in the second placement state easier. This effectively avoids incomplete drainage and cross-contamination of silicon wafers during tank cleaning, thereby improving the problem of watermark defects in silicon wafer products.

[0034] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the silicon wafer cleaning method provided in the embodiments of this application;

[0036] Figure 2 This is a schematic diagram of the first type of flower basket placement state transformation process provided in the embodiments of this application;

[0037] Figure 3 This is a schematic diagram illustrating the second type of flower basket placement state transformation process provided in the embodiments of this application;

[0038] Figure 4 This is a schematic diagram illustrating the third type of flower basket placement state transformation process provided in the embodiments of this application;

[0039] Figure 5 This is a schematic diagram illustrating the fourth type of flower basket placement state transformation process provided in the embodiments of this application;

[0040] Figure 6This is a schematic diagram of the flower basket from a first angle in an embodiment of this application;

[0041] Figure 7 This is a schematic diagram of the flower basket from a second angle in an embodiment of this application;

[0042] Figure 8 This is a schematic diagram illustrating the fifth type of flower basket placement state transformation process provided in the embodiments of this application;

[0043] Figure 9 This is a schematic diagram of the first type of flower basket spacing adjustment process provided in the embodiments of this application;

[0044] Figure 10 This is a schematic diagram of the second type of flower basket spacing adjustment process provided in the embodiments of this application;

[0045] Figure 11 This is a schematic diagram of the third type of flower basket spacing adjustment process provided in the embodiments of this application;

[0046] Figure 12 A schematic diagram illustrating the first type of flower basket spacing and placement state transformation process provided in the embodiments of this application;

[0047] Figure 13 This is a schematic diagram illustrating the second type of flower basket spacing and placement state transformation process provided in the embodiments of this application;

[0048] Figure 14 This is a schematic diagram showing the state of the double-layer flower basket placed in the washing tank in an embodiment of this application;

[0049] Figure 15 This is a schematic diagram of the cleaning system provided in the first embodiment of this application;

[0050] Figure 16 This is a schematic diagram showing the combination of the flipping mechanism and the cleaning tank in an embodiment of this application;

[0051] Figure 17 This is a schematic diagram of the transfer mechanism in the embodiments of this application;

[0052] Figure 18 This is a schematic diagram of the cleaning system provided in the second embodiment of this application;

[0053] Figure 19 This is a schematic diagram of the cleaning system provided in the third embodiment of this application. Detailed Implementation

[0054] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0055] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0056] In the production of solar cells, silicon wafers and solar cells often need to be transferred between different processes. For example, after the finished square rods are sliced ​​and debonded, the silicon wafers need to be transferred to the wafer insertion and cleaning process for wet cleaning. During the cleaning and transfer process, baskets are generally used for centralized loading and transfer. However, problems such as inadequate cleaning of silicon wafers at the top of the basket, incomplete drainage of silicon wafers, and poor watermarks on the products can easily occur during loading and transfer.

[0057] To address the aforementioned problems, this application provides a silicon wafer cleaning method, such as... Figure 1 As shown, steps 101 to 102 are included:

[0058] Step 101: Place the basket containing the silicon wafers into the cleaning tank for cleaning.

[0059] In step 101 above, the silicon wafer is loaded into a basket, and then the basket is lifted as a whole into a cleaning tank for cleaning. The cleaning tank can be a liquid tank or a gas tank such as a water tank, acid tank, alkali tank or nitrogen tank, which has the effect of cleaning or purifying the silicon wafer.

[0060] Step 102: During or after the cleaning process, change the flower basket from the first placement state to the second placement state.

[0061] In step 102 above, when cleaning silicon wafers in the cleaning tank, the basket is controlled to change from the first placement state to the second placement state. That is, the basket's posture is changed by means of flipping or other methods. By changing the posture, the silicon wafers in the basket can be made to come into more full contact with the cleaning material in the cleaning tank according to the cleaning needs. This also allows impurities and oil stains on the silicon wafers to be removed more quickly, further improving the cleaning effect. Of course, the posture can also be changed without changing it in the cleaning tank, but when it is pulled out of the cleaning tank, so as to facilitate the drainage of the silicon wafers. After cleaning is completed (there can be one or more cleaning tanks, that is, cleaning is completed when the last cleaning tank is finished, otherwise it is still in the process of cleaning), the basket is changed from the first placement state to the second placement state, so that it can be lifted in a suitable posture. This avoids problems such as collisions between silicon wafers in the basket or poor product watermarks caused by unstable or improper position during circulation.

[0062] In this embodiment of the application, the first placement state and the second placement state of the flower basket can be definite or indefinite placement states. The change of the flower basket from the first placement state to the second placement state is intended to illustrate that the placement state of the flower basket changes during or after the cleaning process.

[0063] In this embodiment, the basket containing silicon wafers is placed in a cleaning tank for cleaning, and during or after cleaning, the basket is changed from a first placement state to a second placement state. This process of changing the basket from the first to the second placement state during cleaning allows for thorough cleaning of the silicon wafers in the basket, facilitating subsequent lifting according to the second placement state. This effectively avoids incomplete drainage and cross-contamination of silicon wafers during tank cleaning, thereby improving the problem of watermark defects in silicon wafer products.

[0064] Optionally, in one embodiment, step 102 above, changing the flower basket from the first placement state to the second placement state, includes: placing the flower basket inside or outside the cleaning tank, changing it from the first placement state to the second placement state.

[0065] In this implementation, such as Figure 2 As shown, when the flower basket 10 is suitable for changing its placement state in the washing tank 30, it can be changed from the first placement state to the second placement state directly in the washing tank by flipping, moving its position, etc.

[0066] In this implementation, such as Figure 3 As shown, when the flower basket 10 is not suitable for changing its placement state in the cleaning tank 30, it can be changed from the first placement state to the second placement state outside the cleaning tank by flipping or other means.

[0067] Optionally, in one embodiment, in step 102 above, the flower basket is changed from the first placement state to the second placement state in a liquid environment and / or a nitrogen environment.

[0068] In this embodiment, controlling the flower basket to change from the first placement state to the second placement state in a liquid environment or a nitrogen environment can avoid silicon wafer contamination during the placement state change process.

[0069] When changing the flower basket from the first placement state to the second placement state in a liquid environment, the above-mentioned cleaning tank is a liquid tank, that is, it is necessary to add cleaning liquids such as water, acid or alkali to the cleaning tank.

[0070] When changing the flower basket from the first placement state to the second placement state in a nitrogen environment, the cleaning tank can be set as a nitrogen tank. That is, nitrogen needs to be introduced into the cleaning tank through a nitrogen purging mechanism. Specifically, a nitrogen pipeline can be set at the bottom of the cleaning tank, and nitrogen can be introduced during the cleaning process of the flower basket, providing nitrogen from bottom to top to make the cleaning tank present a nitrogen environment. Alternatively, a nitrogen purging mechanism can be set outside the cleaning tank, and when the flower basket is changed from the first placement state to the second placement state, nitrogen can be purged on the flower basket to provide gas protection and prevent the silicon wafer surface from being contaminated, oxidized, or other adverse phenomena.

[0071] Optionally, in one embodiment, the flower basket is loaded with at least two layers of silicon wafers placed along a first direction;

[0072] The transition from the first placement state to the second placement state includes:

[0073] The flower basket is flipped over, changing its orientation from the first direction to the second direction.

[0074] In this embodiment, the first direction is the direction in which the silicon wafers can be stably arranged and loaded in the basket, i.e., the vertical direction; and the silicon wafers are stacked in at least two layers in the basket, which can significantly increase the amount of silicon wafers loaded per unit area of ​​the basket.

[0075] In this embodiment, the first orientation placement state is the basket placement state corresponding to the first direction, which is suitable for inserting silicon wafers into the basket; the second orientation placement state is a different placement state from the first orientation placement state, namely, the horizontal direction. In the second orientation placement state, the silicon wafers can not only be stably and independently arranged and loaded in the basket, but also avoid unstable or improper positions during the transfer, which could cause collisions or scratches between the silicon wafers in the basket. It can also effectively avoid problems such as incomplete drainage and mutual contamination between silicon wafers during the tank cleaning process, which could lead to poor product watermarks.

[0076] For example, when the basket 10 is loaded with two layers of silicon wafers placed along a first direction, and the placement is changed from the first placement state to the second placement state within a single cleaning tank 30, specifically as follows: Figure 4 As shown.

[0077] For example, when the basket 10 contains two layers of silicon wafers placed along a first direction, and the placement changes from the first to the second position outside the cleaning tank 30, specifically as follows: Figure 5 As shown.

[0078] In this embodiment, the flower basket can be a single-layer flower basket or a multi-layer flower basket. A single-layer flower basket is a flower basket with only one layer of storage space; a multi-layer flower basket is a flower basket with multiple layers of storage space, specifically 2, 3, 4, etc. The storage space is used to load single-layer silicon wafers in a vertical position. Since each layer of storage space can hold silicon wafers, the design of the multi-layer storage space enables the flower basket to hold multiple layers of silicon wafers, which can significantly increase the amount of silicon wafers loaded per unit area of ​​the flower basket.

[0079] For example, such as Figure 6 , 7 As shown, the flower basket 10 provided in this embodiment has a multi-layered accommodating space 20 formed by multiple connecting rods 12 and two fixing plates 11, for example, an N-layered accommodating space, where N can be 2, 3 or 4, etc. It can realize the loading capacity of N single-layer flower baskets for silicon wafers. Therefore, when performing wet tank cleaning on silicon wafers, it is equivalent to increasing the number of flower baskets placed in a single cleaning tank to N times without changing the floor area of ​​the cleaning tank. This not only greatly improves the equipment's production capacity but also effectively reduces the consumption of chemicals.

[0080] Optionally, in one specific embodiment, when the flower basket is a multi-layered flower basket, step 102, changing the flower basket from the first placement state to the second placement state, includes: flipping the flower basket from the upright state to the flat state.

[0081] In this specific embodiment, when in the upright state, the flower basket has multiple layers of storage space, which are used to accommodate silicon wafers in the upright state; while in the lying-down state, the flower basket has only one layer of storage space, so that when the flower basket is lifted in the lying-down state, the residual liquid on the upper silicon wafer will not flow to the lower silicon wafer, avoiding watermarks and other undesirable appearance effects.

[0082] In this specific embodiment, when the flower basket is a multi-layered flower basket with multiple storage spaces, the overall height of the flower basket is reduced by flipping it over. This allows the silicon wafers on the upper layer of the flower basket to come into contact with the cleaning substance as needed for cleaning. At the same time, the flipping operation allows impurities and oil stains on the silicon wafers to be removed more quickly, further improving the cleaning effect. On the other hand, when the flower basket is flipped from an upright position to a flat position, the silicon wafers remain upright, and the multiple silicon wafers are arranged side by side in the horizontal direction. Therefore, when the flower basket is lifted in the flat position, the upper and lower silicon wafers will not be contaminated by residual medicine due to the vertical multi-layered distribution, nor will there be contamination and undesirable watermarks caused by drainage.

[0083] Optionally, in one embodiment, at least two flower baskets are provided and arranged along a first direction;

[0084] Changing the flower basket from the first placement state to the second placement state includes:

[0085] The arrangement of the flower baskets is changed from being placed along the first direction to being placed along the second direction.

[0086] In this embodiment, the first direction is an arrangement direction that facilitates placing multiple flower baskets in the cleaning tank, such as a vertical direction; when the silicon wafer is loaded in the flower basket and cleaned in the cleaning tank, at least two flower baskets are arranged along the first direction so that multiple flower baskets can be cleaned at the same time.

[0087] In this embodiment, the second direction is a direction different from the first direction. Specifically, it can be an arrangement direction that facilitates the transfer of multiple baskets, such as a horizontal direction. During or after cleaning, the baskets are changed from being arranged along the first direction to being arranged along the second direction. This arrangement allows the silicon wafers in the baskets at different positions to come into contact with the cleaning material. Furthermore, by adjusting the arrangement, impurities and oil stains on the silicon wafers can be removed more quickly, further improving the cleaning effect. At the same time, after cleaning, the baskets are changed to be arranged along the second direction, so that the baskets are at least vertically staggered. This facilitates the transport by the robotic arm and avoids the problem of cross-contamination of the silicon wafers in the baskets due to water leakage.

[0088] For example, if there are two flower baskets 10, with the first direction being vertical and the second direction being horizontal, then... Figure 8 As shown, the two flower baskets in the cleaning tank 30 are changed from being arranged along the first direction to being arranged along the second direction.

[0089] Optionally, in one embodiment, at least two flower baskets are provided. The silicon wafer cleaning method provided in this application embodiment further includes step 103 before changing the flower baskets from the first placement state to the second placement state:

[0090] Step 103: Adjust the spacing between adjacent flower baskets so that there is a preset spacing between adjacent flower baskets along the second direction.

[0091] In this embodiment, before changing the flower basket from the first placement state to the second placement state, the spacing between adjacent flower baskets along the second direction is adjusted to a preset spacing by means of a robotic arm or transfer mechanism. The existence of the preset spacing allows the flower basket to be changed from the first placement state to the second placement state.

[0092] In practical applications, the second direction is the direction corresponding to the second placement state, specifically the direction that affects whether the flower basket can be placed in the second placement state.

[0093] For example, if there are two flower baskets, and in the first placement state the two flower baskets are arranged horizontally side by side in an upright state, while in the second placement state the two flower baskets are arranged horizontally side by side in a lying state in the first placement state, then the second direction is the horizontal direction.

[0094] For example, if there are two flower baskets, and in the first placement state the two flower baskets are arranged vertically side by side in a flat position, while in the second placement state the two flower baskets are arranged vertically side by side in a standing position in the first placement state, then the second direction is the vertical direction.

[0095] Optionally, in one specific embodiment, the spacing between adjacent flower baskets in the cleaning tank is adjusted to a preset spacing.

[0096] In this specific implementation, such as Figure 9 As shown, when the internal space of the cleaning tank 30 is large enough, at least in the second direction, the spacing between adjacent flower baskets can be adjusted directly within the cleaning tank 30 to the preset spacing.

[0097] Optionally, in one specific embodiment, the flower basket is transferred outside the washing tank, the spacing between adjacent flower baskets is adjusted to a preset spacing outside the washing tank, and then placed into another washing tank.

[0098] In this specific embodiment, multiple flower baskets are simultaneously transferred outside the cleaning tank, and then the distance between adjacent flower baskets in the second direction is adjusted to a preset spacing. Then, they are placed in another cleaning tank, so that the spacing between adjacent flower baskets in the other cleaning tank becomes the preset spacing.

[0099] This specific embodiment is suitable for situations where the internal space of the washing tank in the second direction is insufficient or unsuitable for adjusting the spacing between the flower baskets.

[0100] For example, the process of changing the state of the flower basket in this specific embodiment is as follows: Figure 10 As shown.

[0101] Optionally, in one specific embodiment, the flower baskets are transferred out of the washing tank in sequence, and then placed into another washing tank in sequence at a preset interval.

[0102] In this specific embodiment, the flower baskets are transferred one by one to the outside of the cleaning tank, and then placed into another cleaning tank in sequence according to a preset spacing. This also makes the spacing between adjacent flower baskets in the other cleaning tank the preset spacing.

[0103] For example, the process of changing the state of the flower basket in this specific embodiment is as follows: Figure 11 As shown.

[0104] In this embodiment of the application, after adjusting the spacing between adjacent flower baskets to a preset spacing, each flower basket can be directly changed from the first placement state to the second placement state in the current cleaning tank; or each flower basket can be transferred to another cleaning tank and changed from the first placement state to the second placement state in the other cleaning tank.

[0105] Optionally, in one embodiment, the flower baskets are washed in a first cleaning tank in a first placement state, then lifted and moved horizontally to a second cleaning tank, where the spacing between adjacent flower baskets is adjusted to a preset spacing. Then, each flower basket is lifted and moved horizontally to a third cleaning tank, where it is changed from the first placement state to the second placement state. The corresponding process is as follows: Figure 12 As shown.

[0106] In this embodiment, the first cleaning tank is used to clean the flower basket; the second cleaning tank is used to widen the gap between the flower baskets to facilitate subsequent posture changes; and the third cleaning tank is used to change the posture of the flower baskets.

[0107] In one specific embodiment, when the flower basket is a multi-layered flower basket and the first placement state is an upright placement state, the first cleaning tank is used to accommodate the flower basket in the upright state and having multiple storage spaces; in another specific embodiment, when the flower basket is a multi-layered flower basket and the second placement state is a flat placement state, the second and third cleaning tanks can be widened compared to the first cleaning tank to accommodate the flower basket in the flat placement state.

[0108] In this specific implementation, such as Figure 13As shown, one or more flower baskets 10 are first placed in the first cleaning tank 31 with a small gap for cleaning; then, the flower baskets 10 are pulled apart by lifting and moving them horizontally and placed in the second cleaning tank 32, thereby increasing the gap between the flower baskets 10 to facilitate subsequent posture transformation operations. Compared to the first cleaning tank 31, the second cleaning tank 32 can be widened to match a larger gap between adjacent flower baskets, making it easier for the flower baskets to be transferred in groups to the third cleaning tank for direct posture transformation operations; then, the flower baskets 10 in the second cleaning tank 32 are lifted and moved horizontally in groups of at least two to the third cleaning tank 33 and flipped into a flat position to reduce the appearance defects such as watermarks caused by residual liquid on the upper silicon wafer of the flower basket flowing to the lower silicon wafer during subsequent dehydration and drying. Compared to the first cleaning tank, the third cleaning tank can also be widened to accommodate the flower baskets in the flat position.

[0109] In this specific embodiment, the distance between two adjacent flower baskets in the second cleaning tank can be adjusted to be greater than the height of the flower baskets when they are in an upright state, so that when they are transferred to the third cleaning tank in groups, the flower baskets can be flipped without adjusting the spacing between them.

[0110] Optionally, in this embodiment of the application, the above-mentioned lifting process is carried out along the first direction, and the angle between the first direction and the horizontal direction is 70~90°. That is, when the flower basket is lifted to the first cleaning tank / second cleaning tank / third cleaning tank or pulled out of the first cleaning tank / second cleaning tank / third cleaning tank, it is carried out in a vertical or near-vertical direction, which can quickly lift the flower basket out.

[0111] When retrieving the flower basket, simply lift it out until the bottom of the basket extends beyond the top of the cleaning tank.

[0112] Optionally, in this embodiment of the application, the above translation process is carried out along the second direction, and the angle between the second direction and the horizontal direction is 0~30°. That is, when the flower basket is moved to or away from the first cleaning tank / second cleaning tank / third cleaning tank, it is carried out in the horizontal direction or near the horizontal direction, so that the flower basket can be transferred smoothly.

[0113] In practical applications, during the translation of the flower basket, the translation can be controlled at a second speed, that is, at a fixed speed; or the translation can be controlled at a first speed, a second speed, and a third speed in sequence, wherein the second speed is greater than the first speed and the third speed, that is, the translation is performed at a slower speed at the beginning, at a faster speed in the middle, and at a slower speed at the end.

[0114] Optionally, in one specific embodiment, the lifting time is controlled to be 20~50s, for example, a range of 20s, 30s, 40s, 50s or any two of them, and the flipping time is controlled to be 10~30s, for example, a range of 10s, 12s, 15s, 20s, 30s or any two of them, which can effectively balance the efficiency of basket transfer and the cleaning effect of silicon wafer drainage.

[0115] Optionally, in one embodiment, the silicon wafer cleaning method provided in this application further includes step 104:

[0116] Step 104: After cleaning, dry the flower basket in the second placement state.

[0117] In this embodiment, moving the flower basket horizontally to a drying equipment such as an oven in the second placement state for drying can effectively improve the appearance defects such as watermarks. In particular, when the flower basket is a multi-layered flower basket, it can effectively prevent water from the upper silicon wafer from leaking to the lower silicon wafer, thus avoiding the problem of contamination of the lower silicon wafer.

[0118] In practical applications, after the basket is lifted into the third cleaning tank, the total operation time from flipping it over to lifting it into the drying equipment is controlled within 100-150 seconds, for example, one or any two of 100s, 110s, 120s, 130s, 140s, and 150s. Compared to lifting between cleaning tanks during the cleaning process, the operation time for lifting the basket from the cleaning tank after cleaning is longer. That is, the basket is lifted slowly after cleaning for transfer or subsequent drying. By lifting slowly, it is possible to avoid collisions between silicon wafers that could cause damage. On the other hand, it also allows sufficient time for the basket to lie flat, ensuring that the silicon wafers inside the basket drain more thoroughly.

[0119] In practical applications, the above-mentioned cleaning tanks can be alkaline cleaning tanks, water tanks, mixed acid tanks, ozone cleaning tanks, slow lifting tanks, nitrogen tanks, etc.

[0120] The following example, using a double-layered flower basket with two layers of storage space, in which the first placement state is upright and the second placement state is flat, will further illustrate the cleaning method provided in the embodiments of this application.

[0121] (1) First, place the first flower basket 21 and the second flower basket 22 in the first cleaning tank 31 in an upright position for cleaning, as shown in the following figure. Figure 14 As shown, both the first and second flower baskets have double-layered storage spaces, and each layer of storage space contains a vertically positioned silicon wafer 13.

[0122] (2) Then, using the long hanging plate of the robotic arm, the first flower basket and the second flower basket are lifted and moved horizontally into the second cleaning tank respectively;

[0123] (3) Control the robotic arm to move downwards, and use the robotic arm to lift the first flower basket and the second flower basket at the same time, and move them horizontally to the top of the third cleaning tank. Then control the robotic arm to move downwards, and place the first flower basket and the second flower basket on different flipping brackets of the third cleaning tank respectively. Then the rotary motor drives the flipping brackets to move, thereby flipping the first flower basket and the second flower basket into a flat state with two layers of silicon wafers side by side.

[0124] (4) The rear robotic arm slowly lifts the first and second flower baskets in a horizontal position, and puts each flower basket into the subsequent drying equipment for drying.

[0125] Tests have shown that, compared to slowly lifting the basket while it is upright, flipping the basket to a flat position as described above can reduce the watermark defect rate of silicon wafer products from 15% to 1%.

[0126] This application also provides a silicon wafer cleaning system 100, such as... Figures 15-17 It includes at least one cleaning tank 30 and a flipping mechanism 40. The cleaning tank 30 is used to accommodate a basket 10 loaded with silicon wafers 10, and the flipping mechanism 40 is used to change the basket 10 from a first placement state to a second placement state during or after cleaning.

[0127] In the silicon wafer cleaning system provided in this application embodiment, the presence of a flipping mechanism allows the basket to be changed from a first placement state to a second placement state during or after the cleaning process. This facilitates comprehensive cleaning of the silicon wafers in the basket and makes it easier to lift them out in the second placement state. This effectively avoids the problem of incomplete drainage and cross-contamination of silicon wafers during the tank cleaning process, thereby improving the problem of watermark defects in silicon wafer products.

[0128] The first and second placement states of the flower basket can be definite or indefinite postures. The change from the first placement state to the second placement state is intended to illustrate that the placement state of the flower basket changes during or after the cleaning process.

[0129] In this embodiment, in order to increase the loading capacity and improve the cleaning efficiency, multiple flipping mechanisms are arranged at intervals in the cleaning tank, which can carry multiple of the above-mentioned flower baskets, and can significantly increase the amount of silicon wafers cleaned in a single cleaning process.

[0130] Alternatively, in one implementation, such as Figure 15As shown, the flipping mechanism 40 can be set outside the washing tank and can change the flower basket 10 from the first placement state to the second placement state outside the washing tank after the flower basket 10 is washed.

[0131] In this embodiment, by additionally setting a flipping mechanism 40 outside the cleaning tank, the flower basket can be flipped after cleaning is completed. The flower basket can be controlled to change from the first placement state to the second placement state without modifying the cleaning tank.

[0132] Optionally, in one specific embodiment, the flipping mechanism 40 includes a robotic arm disposed at the top of the washing tank and used to grip the flower basket and control the flipping of the flower basket.

[0133] In this specific embodiment, by additionally installing a robotic arm outside the cleaning tank, the robotic arm can be used to control the flower basket to flip during the cleaning process, and the flower basket can be controlled to change from the first placement state to the second placement state without modifying the cleaning tank.

[0134] Alternatively, in another implementation, such as Figure 16 As shown, the flipping mechanism 40 can be installed in the washing tank, and can change the flower basket 10 from the first placement state to the second placement state in the washing tank 30 during the washing process, or change the flower basket 10 from the first placement state to the second placement state in the washing tank after the flower basket 10 is washed; wherein, by carrying the flower basket 10 on the flipping mechanism 40, the flower basket 10 can be flipped by the flipping mechanism 30, thereby changing the flower basket 10 from the first placement state to the second placement state in the washing tank.

[0135] Two of the aforementioned flipping mechanisms 40 can be provided in the cleaning tank 30, which are used to change the two flower baskets 10 from the first placement state to the second placement state respectively.

[0136] Alternatively, in one specific implementation, such as Figure 16 As shown, the flipping mechanism 40 includes a flower basket seat 41 and a drive unit 42. The flower basket seat 41 is disposed in the cleaning tank 30 to support the flower basket 10. The drive unit 42 drives the flower basket seat 41 to rotate so that the flower basket 10 changes from the first placement state to the second placement state.

[0137] The flower basket holder 41 is mounted in the cleaning tank 30 via a horizontal rotating shaft 43, and the output end of the drive unit 42 is connected to the rotating shaft 43. Rotation of the rotating shaft 43 causes the flower basket holder 41 to rotate around the horizontal rotating shaft 43. The flower basket 10 is mounted on the flower basket holder 41 and will rotate along with the rotation of the flower basket holder 41. Therefore, by controlling the rotation of the horizontal rotating shaft through the drive unit 42, the flipping bracket 41 can be rotated, causing the flower basket 10 to flip, thereby changing the flower basket from the first placement state to the second placement state.

[0138] In this embodiment, the cleaning tank 30 can be a liquid tank or a nitrogen tank, or a nitrogen purging mechanism can be provided outside the cleaning tank 30 to flip and lift the flower basket in a liquid environment or a nitrogen environment.

[0139] Optionally, the flower basket holder 41 has two mutually perpendicular bearing surfaces to support the flower basket in an upright state and a horizontal state, respectively.

[0140] Optionally, in a more specific embodiment, the flower basket seat 41 is L-shaped or bucket-shaped, which facilitates changing the flower basket 10 from a lying position to an upright position or vice versa, and the lifting device can smoothly lift the flower basket regardless of whether it is in an upright or lying position.

[0141] The drive unit 42 can be a motor, and the output end of the motor is connected to the rotating shaft 43 via a transmission belt 44. Optionally, a rotating gear 45 is provided at one end of the rotating shaft 43, and the transmission belt 44 is wound around the rotating gear 45 and the output end of the motor, thereby realizing the transmission connection between the rotating shaft 43 and the motor.

[0142] Alternatively, in a more specific embodiment, when the cleaning tank 30 is a liquid tank, such as... Figure 16 As shown, the motor is cantilevered above the cleaning tank to protect it from liquid corrosion.

[0143] Alternatively, in another specific embodiment, when the cleaning tank 30 is a nitrogen tank, the motor is located at the bottom of the cleaning tank and is driven by the rotating shaft 43 through a conveyor belt 44 or a rotating gear 45 to improve the driving efficiency.

[0144] Optionally, in one embodiment, the cleaning system provided in this application further includes a transfer mechanism 50, which is used to transfer the flower baskets in the cleaning tank so as to adjust the spacing between adjacent flower baskets before changing the flower baskets from the first placement state to the second placement state, so that the adjacent flower baskets have a preset spacing along the second direction.

[0145] The aforementioned transfer mechanism can adjust the spacing between adjacent flower baskets to a preset spacing within the cleaning tank; or, transfer the flower baskets outside the cleaning tank, adjust the spacing between adjacent flower baskets to a preset spacing outside the cleaning tank, and then place them into another cleaning tank; or, transfer the flower baskets sequentially outside the cleaning tank and then place them sequentially into another cleaning tank according to the preset spacing.

[0146] Alternatively, in one specific implementation, such as Figure 17 As shown, the aforementioned transfer mechanism 50 includes a first transfer member 51 and two second transfer members 52, with the two second transfer members 52 respectively disposed on both sides of the first transfer member 51. The first transfer member 51 is used to lift a single flower basket 10 into the cleaning tank 30, and the second transfer members are used to lift two flower baskets 10 together into or out of the cleaning tank 30. Optionally, the first transfer member 51 can be a long hanging plate, and the second transfer member 52 can be a short hanging plate.

[0147] Alternatively, in one specific implementation, such as Figure 15 As shown, the at least one cleaning tank 30 includes a first cleaning tank 31, which is a tank for cleaning the flower basket and for changing the flower basket from a first placement state to a second placement state during or after the cleaning process.

[0148] The internal space of the first cleaning tank is sufficient to accommodate the flower basket in the first placement state and the second placement state; optionally, the flower basket is a multi-layer flower basket loaded with at least two layers of silicon wafers placed along the first direction, and the first placement state is an upright state and the second placement state is a flat state. The first cleaning tank can be heightened along the first direction to accommodate the flower basket in the upright state and having a multi-layered storage space.

[0149] Alternatively, in one specific implementation, such as Figure 18 As shown, the at least one cleaning tank 30 includes a first cleaning tank 31 and a second cleaning tank 32. The first cleaning tank is used to clean the flower basket in a first placement state; the second cleaning tank is used to accommodate the flower basket when it changes from the first placement state to the second placement state.

[0150] The interior space of the first cleaning tank is sufficient to accommodate the flower basket in its first placement state;

[0151] Optionally, the flower basket is a multi-layer flower basket containing at least two layers of silicon wafers placed along a first direction, and the first placement state is an upright state and the second placement state is a lying state. The first cleaning tank should be heightened along the first direction to accommodate the flower basket in the upright state and having multiple layers of storage space; the second cleaning tank is widened to accommodate the flower basket 10 in the lying state.

[0152] Alternatively, in one specific implementation, such as Figure 19 As shown, the at least one cleaning tank 30 includes a first cleaning tank 31, a second cleaning tank 32, and a third cleaning tank 33; the first cleaning tank 31 is used to clean at least two flower baskets in a first placement state; the second cleaning tank 32 is used to accommodate at least two flower baskets having a preset distance in a second direction before the flower baskets are changed from the first placement state to the second placement state; the third cleaning tank 33 is used to accommodate the flower baskets that have been changed from the first placement state to the second placement state.

[0153] Optionally, the flower basket is a multi-layered flower basket containing at least two layers of silicon wafers placed along a first direction, and the first placement state is an upright state and the second placement state is a lying state. In this case, the first cleaning tank can be heightened to accommodate the flower basket in the upright state and having multiple layers of storage space. The second cleaning tank is a tank used to widen the spacing between the flower baskets to facilitate subsequent flipping. The third cleaning tank is a tank used to flip the flower baskets. Compared with the first cleaning tank, the third cleaning tank should be widened to accommodate the flower basket in the lying state.

[0154] In this specific embodiment, one or more flower baskets 10 are first placed in the first cleaning tank 31 with a small gap for cleaning; then, the flower baskets 10 are pulled apart by lifting and sliding and placed in the second cleaning tank 32, thereby increasing the gap between the flower baskets 10 to facilitate subsequent flipping operations. Compared to the first cleaning tank 31, the second cleaning tank 32 should be widened to match the larger gap between adjacent flower baskets, making it easier for the flower baskets to be transferred in groups to the third cleaning tank for direct flipping; then as... Figure 4 As shown, the flower baskets 10 in the second cleaning tank 32 are lifted and moved horizontally in groups of at least two to the third cleaning tank 33 and turned into a flat position. This is to reduce the appearance defects caused by residual liquid on the upper silicon wafer of the flower basket flowing to the lower silicon wafer during subsequent dehydration and drying. Compared with the first cleaning tank, the third cleaning tank should also be widened to accommodate the flower baskets in the flat position.

[0155] Optionally, in one specific embodiment, the distance between two adjacent flower baskets in the second cleaning tank is greater than the height of the flower baskets when they are in an upright state, so that when they are transferred to the third cleaning tank in groups, the flower baskets can be flipped without adjusting the spacing between them.

[0156] In practical applications, such as Figure 18 As shown, the width of the second cleaning tank 32 is sufficient to allow the robotic arm to simultaneously grip at least two of the aforementioned flower baskets, meaning that the robotic arm can ensure smooth operation when simultaneously gripping the first flower basket 21 and the second flower basket 22.

[0157] Alternatively, in one implementation, such as Figure 15 ,18 As shown in Figure 19, the cleaning system provided in this application embodiment also includes a nitrogen purging mechanism 60, which is used to blow nitrogen into and / or outside the cleaning tank to create a nitrogen environment for the flower basket, so as to change the flower basket from the first placement state to the second placement state in the nitrogen environment.

[0158] Optionally, in one specific embodiment, the nitrogen purging mechanism includes a nitrogen pipeline (not shown) disposed at the bottom of the cleaning tank 60, the nitrogen pipeline being used to supply nitrogen to the bottom of the cleaning tank.

[0159] Alternatively, in one implementation, such as Figure 15 , 18 As shown in Figures 1 and 19, the cleaning system provided in this application embodiment also includes a drying device 70, which is connected to the cleaning tank 30 and is used to dry the flower basket in the second placement state.

[0160] The aforementioned drying device 70 can be an oven or similar device.

[0161] In summary, in this embodiment, when cleaning in the cleaning tank, the basket is flipped from an upright position to a flat position. This facilitates comprehensive cleaning of the silicon wafers in the basket and also makes it easier to lift them out in the flat position later. Lifting the basket in the flat position can effectively avoid the problem of residual chemicals in the upper space contaminating the lower space during the tank cleaning process, thereby improving the problem of watermark defects on silicon wafer products.

[0162] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0163] Although optional embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the optional embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.

[0164] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used merely to distinguish one entity from another, and do not necessarily require or imply any such actual relationship or order between these entities. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or terminal device that includes that element.

[0165] The technical solutions provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the principles and implementation methods of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A silicon wafer cleaning method, characterized in that, include: The basket containing the silicon wafers is placed in the cleaning tank for cleaning; During or after the cleaning process, the flower basket is changed from the first placement state to the second placement state; The flower basket has multiple layers of storage space, and the silicon wafer is in an upright position in both the first placement state and the second placement state. The flower basket is loaded with at least two layers of silicon wafers placed along a first direction; The transition from the first placement state to the second placement state includes: The flower basket is flipped over, changing its orientation from the first direction to the second direction.

2. The cleaning method as described in claim 1, characterized in that, The flower basket is placed inside or outside the cleaning tank, changing from the first placement state to the second placement state.

3. The cleaning method as described in claim 1, characterized in that, The flower basket is placed in a liquid environment and / or a nitrogen environment, and then changed from the first placement state to the second placement state.

4. The cleaning method as described in claim 1, characterized in that, The flower baskets are set to at least two and arranged along a first direction; Changing the flower basket from the first placement state to the second placement state includes: The arrangement of the flower baskets is changed from being placed along the first direction to being placed along the second direction.

5. The cleaning method as described in claim 1, characterized in that, The flower baskets are configured in at least two forms, and before changing the flower baskets from the first placement state to the second placement state, the method further includes: Adjust the spacing between adjacent flower baskets so that there is a preset spacing between adjacent flower baskets along the second direction.

6. The cleaning method as described in claim 5, characterized in that, Adjust the spacing between adjacent flower baskets to a preset spacing within the cleaning tank; or, transfer the flower baskets outside the cleaning tank, adjust the spacing between adjacent flower baskets to a preset spacing outside the cleaning tank, and then place them into another cleaning tank. Alternatively, the flower baskets can be moved out of the washing tank one by one, and then placed into another washing tank according to the preset spacing.

7. The method according to any one of claims 1 to 5, characterized in that, Also includes: After cleaning, the flower basket is dried in the second placement state.

8. A silicon wafer cleaning system, characterized in that, Includes at least one cleaning tank and a tilting mechanism; The cleaning tank is used to hold a basket containing silicon wafers; The flipping mechanism is used to change the flower basket from a first placement state to a second placement state during or after the cleaning process. The flower basket has multiple layers of storage space, and the silicon wafer is in an upright position in both the first placement state and the second placement state. The flipping mechanism includes a flower basket seat and a drive unit. The flower basket seat is disposed in the cleaning tank to support the flower basket. The drive unit drives the flower basket seat to rotate so that the flower basket changes from the first placement state to the second placement state.

9. The cleaning system according to claim 8, characterized in that, The flipping mechanism is located outside the washing tank and is used to transfer the flower basket and change the flower basket from the first placement state to the second placement state.

10. The cleaning system according to claim 8, characterized in that, It also includes a transfer mechanism for transferring the flower baskets within the cleaning tank.

11. The cleaning system according to claim 10, characterized in that, The transfer mechanism includes a first transfer member and two second transfer members, with the two second transfer members respectively located on both sides of the first transfer member.

12. The cleaning system according to claim 8, characterized in that, It also includes a nitrogen purging mechanism, which is used to blow nitrogen into and / or outside the cleaning tank.

13. The cleaning system according to claim 8, characterized in that, The cleaning system also includes a drying device connected to the cleaning tank, used to dry the flower basket in the second placement state.

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