Wafer cleaning device and cleaning method

Abstract

The invention relates to a wafer cleaning device and a cleaning method, and relates to the technical field of semiconductor equipment, the wafer cleaning device comprises a control structure, bearing structures, a pair of roller brushes and a pair of force application structures, the multiple sets of bearing structures are provided with wafer bearing surfaces for bearing edge parts of wafers, the multiple sets of bearing structures rotate to drive the wafers to rotate, and the force application structures are used for applying force to the roller brushes. The pair of roller brushes are oppositely arranged on the upper side and the lower side of the wafer bearing surface, and the roller brushes press the surface of the wafer and scrub the wafer in a rolling manner when the wafer rotates; the pair of force application structures and the pair of roller brushes are arranged in a one-to-one correspondence mode, and the control structure is connected with the pair of force application mechanisms, presets a pressure range, detects the pressure applied to the wafer by the roller brushes, and controls the force application structures to drive the corresponding roller brushes to move up and down relative to the wafer according to the magnitude of the pressure relative to the preset pressure range. And applying pressure when the roller brush scrubs the wafer in a rolling manner, and maintaining the pressure to be within a preset pressure range. According to the invention, the conditions that the wafer cleaning effect is poor and the wafer is crushed can be effectively reduced.

Description

Technical Field

[0001] This application relates to the field of semiconductor equipment technology, and in particular to a wafer cleaning apparatus and cleaning method. Background Technology

[0002] 3D stacking is one of the core technologies for manufacturing artificial intelligence chips and has been widely used in the manufacture of high-end products such as 3D NAND memory and high-bandwidth memory (HBM). In this process, the edges of the wafers must be precisely trimmed and ultra-cleaned before stacking to ensure the integrity, uniformity, and overall yield of the stacking interface.

[0003] Wafer edge trimming is primarily used to remove defects, residual material, or geometric irregularities from the edge areas. Insufficient trimming can easily lead to gaps, stress concentrations, or alignment deviations during the stacking process, thereby affecting the electrical performance and long-term reliability of the device.

[0004] More importantly, the 3D stacking process places extremely high demands on cleanliness. The cleanliness level of the wafer surface after cleaning must meet the CLASS 1 cleanliness standard (i.e., no more than one particle ≥0.1μm per cubic foot of air). Especially after edge trimming, the complex morphology makes it more prone to residual particles, organic matter, and metallic contaminants. Incomplete cleaning will directly lead to interlayer contamination, severely reducing product yield. However, existing cleaning equipment still falls short in terms of cleaning efficiency, uniformity, and CLASS 1 cleanliness assurance for edge areas, making it difficult to fully meet the increasingly demanding manufacturing requirements of the 3D stacking process. Summary of the Invention

[0005] This application provides a novel wafer cleaning device that can precisely adjust the position of the brush relative to the wafer, so that the brush can press and clean the wafer at a preset pressure range, thereby ensuring that the wafer after ring cutting meets the extremely high cleanliness standards required for 3D IC stacking and solving the contamination problem caused by wafer ring cutting.

[0006] Firstly, the wafer cleaning apparatus provided in this application adopts the following technical solution: A wafer cleaning apparatus, comprising: Multiple sets of support structures, each having a wafer support surface that supports the edge portion of the wafer, wherein the multiple sets of support structures rotate to drive the wafer to rotate; A pair of roller brushes are arranged opposite each other on the upper and lower sides of the wafer bearing surface. The roller brushes press against the wafer surface and roll and brush it when the wafer rotates. A pair of force-applying structures are provided, each corresponding to one of the pair of roller brushes; A control structure is connected to a pair of the force-applying mechanisms. The control structure presets a pressure range and detects the pressure applied to the wafer by the roller brush. Based on the magnitude of the pressure relative to the preset pressure range, the control structure controls the force-applying mechanism to drive the corresponding roller brush to move up and down relative to the wafer, so that the roller brush applies and maintains pressure within the preset pressure range when it rolls and brushes the wafer. When the pressure is within the preset pressure range, the roller brush maintains its current position; when the pressure exceeds the preset pressure range, the force-applying structure drives the corresponding roller brush to move away from the wafer; when the pressure is below the preset pressure range, the force-applying structure drives the corresponding roller brush to move towards the wafer.

[0007] Furthermore, the preset pressure range is determined based on the compression amount of the roller brush, and includes: Obtain the compression amount of the roller brush; Based on the compression of the roller brush, a theoretical pressure value is determined, wherein the theoretical pressure value is positively correlated with the compression of the roller brush. Based on the theoretical pressure value, determine the minimum and maximum pressure values ​​of the preset pressure range to obtain the preset pressure range.

[0008] Furthermore, the force-applying structure includes a first cylinder, which is connected to and drives the corresponding roller brush to move. When the roller brush presses onto the wafer by adjusting the internal air pressure, the roller brush applies pressure to the wafer and maintains the pressure within a preset pressure range.

[0009] Furthermore, the force-applying structure also includes a second cylinder with a higher moving speed than the first cylinder. The second cylinder is connected to the corresponding roller brush and drives the roller brush to contact the wafer surface.

[0010] Furthermore, the force-applying structure also includes an elastic element, the two ends of which are respectively connected to the first cylinder and its corresponding roller brush.

[0011] Furthermore, it also includes a control structure connected to the first cylinder, which includes: A pressure sensor that acquires the actual pressure applied by the roller brush to the wafer; The controller, which is electrically connected to the first cylinder, adjusts the internal air pressure of the first cylinder according to the difference between the actual pressure and the theoretical pressure, wherein the rate of adjustment of the internal air pressure of the first cylinder is positively correlated with the difference between the actual pressure and the theoretical pressure.

[0012] Furthermore, the pair of roller brushes includes an upper roller brush and a lower roller brush arranged opposite each other, wherein the compression amount of the lower roller brush is lower than that of the upper roller brush.

[0013] Furthermore, the supporting structure is provided with a peripheral cleaning structure, the peripheral cleaning structure comprising: A passive wheel, whose rotation is mounted on the load-bearing structure; A sponge brush, which is fitted onto the passive wheel, is pressed against the circumferential surface of the wafer to perform rolling brushing.

[0014] Furthermore, it also includes an adjustment structure, which is disposed on the periphery of the bearing structure and on which the passive wheel is rotatably disposed. The adjustment structure drives the passive wheel to move, so that the sponge brush is pressed onto the wafer at a preset pressure range when cleaning the wafer.

[0015] Furthermore, the peripheral cleaning structure also includes an idler wheel, and the driven wheel is connected to the bearing structure via the idler wheel; The adjustment structure includes: A base on which the passive wheel is disposed, the base being disposed on the bearing structure, the passive wheel being laterally moved relative to the base to adjust its distance from the circumferential surface of the wafer; An adjusting block is provided with the idler wheel. The adjusting block is movably disposed on the base. The position of the idler wheel is adjusted by lateral movement and rotation relative to the base, so that the idler wheel is connected to the bearing structure and the driven wheel drive respectively.

[0016] Secondly, this application provides a wafer cleaning method using the aforementioned wafer cleaning apparatus, the cleaning method comprising the following steps: S100, The wafer to be cleaned is transported to the wafer support surface and the wafer is clamped; S200, causes the wafer to rotate; S300: Output cleaning fluid to the surface of the wafer to wet and pre-clean the wafer; S400: Move the roller brushes on the upper and lower sides of the wafer until they contact the wafer surface, and adjust the pressure of the upper and lower roller brushes pressing against the wafer surface to the preset pressure range so that the roller brushes clean the upper and lower surfaces of the wafer. S500, wafer cleaning completed, wafer obtained.

[0017] Further, adjusting the pressure of the upper and lower roller brushes pressing against the wafer surface to a preset pressure range includes the following steps: Based on the force balance model constructed by the roller brush: F 推 =F 阻 +F 辊刷-晶圆 Among them, F 推 F is the thrust applied to the roller brush by the force-applying structure. 阻 F is the resistance force experienced by the structure when it moves under the applied force. 辊刷-晶圆 The F is the pressure exerted on the wafer when it is pressed by the roller brush. 辊刷-晶圆 It is positively correlated with the actual compression of the roller brush; F is determined based on the theoretical compression of the roller brush. 辊刷-晶圆 The range of values ​​for the preset pressure range is determined; The displacement of the roller brush is measured and the actual compression of the roller brush is obtained. Based on the actual compression of the roller brush, the thrust applied to the roller brush by the force-applying structure is adjusted.

[0018] In summary, this application includes at least one of the following beneficial technical effects: By controlling the operation of the force-applying structure, the position of the brush relative to the wafer can be precisely adjusted, allowing the brush to press and clean the wafer within a preset pressure range. This ensures the cleaning effect while also protecting the wafer, effectively reducing the chances of poor wafer cleaning or wafer breakage. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural schematic diagram of the wafer cleaning apparatus in this application; Figure 2 This is a simplified planar schematic diagram of the wafer cleaning apparatus in this application; Figure 3 This is a three-dimensional structural diagram of the multiple supporting structures in this application; Figure 4 This is a three-dimensional structural diagram of the supporting structure and the circumferential cleaning structure in this application; Figure 5 This is an exploded structural diagram of the supporting structure and circumferential cleaning structure in this application; Figure 6 This is a diagram of the movement trajectory of the idler wheel in this application; Figure 7 This is an exploded structural diagram of the supporting structure and spraying structure in this application; In the picture: 100. Support structure; 110. Wafer support surface; 120. Wafer holder; 130. Limiting part; 140. Drive wheel; 200. Roller brush; 210. Upper roller brush; 220. Lower roller brush; 300. Force-applying structure; 310. First cylinder; 320. Second cylinder; 330. Elastic element; 400. Control structure; 500. Circumferential cleaning structure; 510. Driven wheel; 520. Sponge brush; 540. Idler wheel; 600. Adjustment structure; 610. Base; 611. Movable hole; 612. Fixing hole; 613. Slide rail; 620. Adjustment block; 630. First adjustment shaft; 640. Second adjustment shaft; 650. Fastener; 700. Spraying structure; 710. Fluid nozzle; 720. Spray pipe; 800. Drive unit. Detailed Implementation

[0020] The following will be combined with the appendix Figure 1-7 The technical solution of this application is clearly and completely described. The following embodiments are exemplary and are only used to explain this application, and should not be construed as limiting this application. In the following description, the same reference numerals are used to denote the same or equivalent elements, and repeated descriptions are omitted.

[0021] In the description of this application, it should be understood that the terms "upper", "lower", "inner", "outer", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this application and to simplify the description, and are not intended to indicate or imply that the equipment or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0022] Furthermore, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0023] It should also be further understood that the term “and / or” as used in this application refers to any combination of one or more of the listed items, and all possible combinations thereof.

[0024] Example 1: A wafer cleaning apparatus, as described above Figure 1 and Figure 2 It includes multiple sets of support structures 100 and a pair of roller brushes 200. Each set of support structures 100 has a wafer support surface 110 that supports the edge of the wafer, and the pair of roller brushes 200 are arranged opposite to each other on the upper and lower sides of the wafer support surface 110.

[0025] The wafer to be cleaned is placed in the center of multiple sets of support structures 100, with its edges supported by wafer support surfaces 110. The wafer is confined in the center of multiple sets of support structures 100. The multiple sets of support structures 100 rotate to drive the wafer to rotate. The roller brush 200 presses onto the wafer surface and rolls and brushes it as the wafer rotates.

[0026] Specifically, the support structure 100 includes a drive wheel 140, which rotates to drive the wafer to rotate.

[0027] Multiple sets of support structures 100 are arranged in a ring-shaped trajectory to provide better support for the wafer. The number of support structures 100 can be set according to the actual situation. It can be set to 3, 4, 5, 6 or even more.

[0028] For example, in this embodiment, there are four supporting structures 100.

[0029] Furthermore, referring to Figure 3 and Figure 4 The support structure 100 includes a wafer base 120 and a limiting part 130 disposed on the wafer base 120 and in clearance fit with the top surface of the wafer base 120. The top surface of the wafer base 120 is the wafer support surface 110. When the wafer is limited to the center of the multiple sets of support structures 100, the edge of the wafer is supported by the wafer support surface 110 and limited by the wafer base 120 and the limiting part 130.

[0030] For example, the gap between the wafer holder 120 and the limiting part 130 is adjustable. That is, the limiting part 130 is telescopically disposed on the wafer holder 120 to accommodate wafers of different thicknesses, so that the wafer can be better limited before being cleaned.

[0031] For example, the gap between the wafer mount 120 and the limiting portion 130 is constant. That is, the limiting portion 130 is fixed on the wafer mount 120.

[0032] Furthermore, the number of support structures 100 is set to an even number, and based on the above example, it is preferably four. The four support structures 100 are grouped in pairs, and in each group of support structures 100, a drive unit 800 is connected between adjacent support structures 100. The output end of the drive unit 800 is connected to the support structure 100, and by extending or retracting the output end, the two support structures 100 move closer or further apart synchronously.

[0033] Specifically, when placing the wafer, the two support structures 100 are moved away synchronously to increase the spacing. After the wafer is placed, the two support structures 100 are moved closer synchronously to decrease the spacing and limit the wafer. After the wafer is cleaned, the two support structures 100 are moved away synchronously again to increase the spacing and remove the wafer.

[0034] During cleaning, the wafer rotates to cooperate with the roller brush 200, so that the surface of the wafer can be cleaned comprehensively and evenly by the roller brush 200. During the cleaning process, the wafer is limited by the wafer holder 120 and the limiting part 130, which can effectively reduce the situation of the wafer shifting or flying out during high-speed rotation.

[0035] For example, the number of support structures 100 is set to an odd number. In this case, the support structures 100 are grouped in pairs. The remaining support structure 100 can be driven by a driving part 800 to move closer to or away from the wafer center, or it can be left without a driving part 800 so that its position remains unchanged.

[0036] It should be noted that this embodiment does not limit the specific form of the drive unit 800, which can be set as a cylinder, motor, etc.

[0037] Reference Figure 2 The wafer cleaning device also includes a control structure 400 and a pair of force-applying structures 300. The pair of force-applying structures 300 are configured one-to-one with a pair of roller brushes 200. The control structure 400 is connected to the pair of force-applying structures 300. The control structure 400 presets a pressure range and detects the pressure applied to the wafer by the roller brushes 200. Based on the magnitude of the pressure relative to the preset pressure range, the control structure 300 drives the corresponding roller brushes 200 to move up and down relative to the wafer, so that the roller brushes 200 apply and maintain pressure within the preset pressure range when they roll and brush the wafer.

[0038] The roller brush 200 cleans the wafer at a pressure within a preset pressure range, ensuring that the cleaning pressure applied to the wafer is always accurately and stably maintained within the set safety value, so as to ensure the cleaning effect of the roller brush 200 on the wafer and protect the wafer to reduce the risk of it being scratched or crushed.

[0039] For ease of explanation, the actual pressure applied to the wafer by the roller brush 200 is denoted as P_actual, and the preset pressure range is denoted as P_set.

[0040] When the pressure is within the preset pressure range (P_actual is within P_set), it indicates that the pressure is within the ideal range, and the roller brush 200 maintains its current position.

[0041] When the pressure exceeds the preset pressure range (P_actual > P_set), it indicates that the pressure is too high and there is a risk of damaging the wafer. The force-applying structure 300 drives the corresponding roller brush 200 to move away from the wafer.

[0042] When the pressure is lower than the preset pressure range (P_actual < P_set), it indicates that the pressure is too low, which may lead to incomplete cleaning. The force-applying structure 300 drives the corresponding roller brush 200 to move toward the wafer.

[0043] The aforementioned detection-comparison-adjustment process is repeated at an extremely high frequency. For example, the process runs at a frequency of 100 times / second. Therefore, even if the roller brush 200 wears down after long-term use, the control structure 400 can respond instantly and compensate, thus ensuring that P_actual always dynamically and closely follows P_set throughout the entire cleaning process.

[0044] Furthermore, the preset pressure range is determined based on the compression amount of the roller brush 200, which includes the following steps: P100, obtain the compression amount of roller brush 200.

[0045] P200. Based on the compression of the roller brush 200, determine the theoretical pressure value, wherein the theoretical pressure value is positively correlated with the compression of the roller brush 200.

[0046] Specifically, the theoretical values ​​for compression and pressure are shown in Table 1.

[0047] Table 1 When the brush is compressed, it applies a pressure F perpendicular to the surface of the wafer. 辊刷-晶圆 F 辊刷-晶圆 =kL, where k is the elastic coefficient of the brush and L is the actual compression of the brush.

[0048] For example, when the brush compression is 200 μm, the pressure applied to the wafer is 2 N. Similarly, when the brush compression is 1200 μm, the pressure applied to the wafer is 12 N. That is, the theoretical pressure applied to the wafer by the brush is positively correlated with the brush compression, and the theoretical pressure applied to the wafer by the brush through compression is 0-12 N.

[0049] P300. Based on the theoretical pressure value, determine the minimum and maximum pressure values ​​of the preset pressure range to obtain the preset pressure range.

[0050] Specifically, the pair of roller brushes 200 includes an upper roller brush 210 and a lower roller brush 220 arranged opposite each other. The compression of the lower roller brush 220 is lower than that of the upper roller brush 210, so that the wafer can be better positioned on the wafer support surface 110. When the roller brushes clean the wafer, both the upper roller brush 210 and the lower roller brush 220 apply pressure to the wafer.

[0051] Both the upper roller brush 210 and the lower roller brush 220 correspond to a preset pressure range. The two preset pressure ranges can be kept consistent or set differently according to the position of the roller brushes.

[0052] For example, based on the determined theoretical pressure value, the preset pressure range for both the upper and lower roller brushes is set to 4-5N.

[0053] For example, in order to better protect the wafer, the preset pressure range of the upper roller brush is further set to 8-10N, and the preset pressure range of the lower roller brush is set to 4-5N.

[0054] Correspondingly, in a specific embodiment, the compression amount of the upper roller brush 210 is set to be less than 1000 μm, and the compression amount of the lower roller brush 220 is set to be less than 500 μm. That is, the lowest position of the upper roller brush 210 when it moves downward is not lower than a-1000 μm, and the highest position of the lower roller brush 220 when it moves upward is not higher than b+500 μm. Wherein, a is the position of the upper surface of the wafer, and b is the position of the lower surface of the wafer.

[0055] By constraining the positions of the upper roller brush 210 and the lower roller brush 220, the excessive pressure on the wafer during the movement of the roller brush 200 is reduced. It should also be noted that the positions of the upper and lower surfaces of the wafer are obtained after the wafer is placed on the support structure.

[0056] Reference Figure 1 The force-applying structure 300 includes a first cylinder 310, which is connected to the corresponding roller brush 200 and drives it to move. When the roller brush 200 presses onto the wafer by adjusting the internal air pressure, the first cylinder 310 applies pressure to the wafer and maintains the pressure within a preset pressure range.

[0057] For example, the first cylinder 310 is configured as a low-friction cylinder. It has a lower minimum operating pressure, and with the cylinder bore and input cylinder air pressure being the same, the actual thrust generated by the low-friction cylinder is closer to the theoretical thrust than that of a conventional cylinder. The pressure formed when the roller brush 200 is pressed onto the wafer is adjusted by regulating the internal air pressure.

[0058] Correspondingly, the control structure 400 includes a pressure sensor and a controller electrically connected to the first cylinder 310. A preset pressure range is set in the controller, and the controller adjusts the internal air pressure of the first cylinder 310 according to the difference between the actual pressure and the theoretical pressure.

[0059] Among them, the rate at which the internal air pressure of the first cylinder 310 is adjusted is positively correlated with the difference between the actual pressure and the theoretical pressure.

[0060] Specifically, the internal air pressure regulation rate = K·(theoretical pressure - actual pressure) / theoretical pressure. The larger the difference between the theoretical pressure and the actual pressure, the larger the regulation rate. The positive or negative value of the regulation rate represents the increase or decrease of the internal air pressure. When the regulation rate is positive, the internal air pressure of the first cylinder 310 increases; when the regulation rate is negative, the internal air pressure of the first cylinder 310 decreases.

[0061] Furthermore, the force-applying structure 300 also includes a second cylinder 320 with a higher moving speed than the first cylinder 310.

[0062] For example, the second cylinder 320 is configured as a dual cylinder.

[0063] The second cylinder 320 is connected to the corresponding roller brush 200, which drives the roller brush 320 to contact the wafer surface. The second cylinder 320 drives the corresponding roller brush 200 to move more rapidly and with a greater stroke than the first cylinder 310, so as to quickly move the roller brush 200 to the target position. At this time, the roller brush 200 does not apply pressure to the wafer.

[0064] For example, both the upper roller brush 210 and the lower roller brush 220 are connected to a second cylinder 320 that drives them to move. The second cylinder 320 can drive the roller brush 200 away from the support structure 100 before placing the wafer and make timely avoidance, so as to facilitate the placement of the wafer.

[0065] For example, the upper roller brush 210 is connected to a second cylinder 320 that drives its movement. That is, only the upper roller brush 210 is driven to lift upwards to avoid the wafer, thereby reducing the number of second cylinders 320 and optimizing the overall structure of the cleaning device. In this example, the lower roller brush 220 is positioned such that when the wafer is transported onto the wafer support surface 110, the lower roller brush 220 is already in contact with the wafer.

[0066] Meanwhile, considering that the upper roller brush 210 is further affected by its own gravity when applying pressure to the wafer, and that the first cylinder 310 has a low operating pressure, making it difficult to push the corresponding roller brush 200, in a specific embodiment, an elastic element 330 is connected between the roller brush 200 and the first cylinder 310. The weight of the roller brush 200 is balanced by the extension or contraction of the spring.

[0067] For example, the aforementioned elastic element 330 is provided between the upper roller brush 210 and the corresponding first cylinder 310, and between the lower roller brush 220 and the corresponding first cylinder 310.

[0068] For example, the above-mentioned elastic element 330 is provided between the upper roller brush 210 and the corresponding first cylinder 310.

[0069] The following section will further explain how the upper roller brush 210 applies pressure to the wafer and maintains pressure within a preset range.

[0070] T100 and the second cylinder 320 drive the first cylinder 310 and the upper roller brush 210 to move downwards until the upper roller brush 210 contacts the upper surface of the wafer. The upper roller brush 210 does not apply pressure to the wafer when it contacts the wafer.

[0071] T200 and the first cylinder 310 move downwards, causing the upper roller brush 210 to move further downwards. At this time, the elastic element 330 contracts, and the upper roller brush 210 applies pressure to the upper surface of the wafer.

[0072] Detects the pressure applied to the wafer by the upper roller brush 210: If the pressure is within the preset pressure range, the air pressure of the first cylinder 310 remains unchanged.

[0073] If the pressure exceeds the preset pressure range, the air pressure supplied to the first cylinder 310 is reduced. Since the elastic force of the elastic element 330 equals the weight of the upper roller brush 210 plus the downward pulling force of the first cylinder 310, the downward pulling force of the first cylinder 310 decreases as the air pressure decreases. At this time, the elastic force of the elastic element 330 is greater than the weight of the upper roller brush 210 plus the downward pulling force of the first cylinder 310. The elastic element 330 stretches until the elastic force of the spring, the weight, and the pulling force are balanced again, and the pressure applied by the upper roller brush 210 to the wafer decreases.

[0074] If the pressure exceeds the preset pressure range, the air pressure supplied to the first cylinder 310 is increased. The downward pulling force of the first cylinder 310 is correspondingly increased. At this time, the elastic force of the elastic element 330 is less than the weight of the upper roller brush 210 plus the downward pulling force of the first cylinder 310. The elastic element 330 is compressed, and the pressure applied by the upper roller brush 210 to the wafer increases.

[0075] The pressure is adjusted cyclically according to the two scenarios described above to maintain it within the preset pressure range. It should be noted that the method by which the lower roller brush 220 applies pressure to the wafer is the same as that of the upper roller brush 210, both involving adjusting the air pressure of the corresponding first cylinder 310 connected to them; further details will not be elaborated here.

[0076] Furthermore, referring to Figure 4 and Figure 5 The support structure 100 is provided with a peripheral cleaning structure 500. The peripheral cleaning structure 500 cleans the peripheral surface of the wafer, so as to cooperate with the roller brush 200 to perform a more comprehensive cleaning of the wafer. The cleaning of the peripheral surface of the wafer also further reduces the possibility that dirt on the peripheral surface of the wafer will be embedded or pressed into the wafer when the support structure 100 drives the wafer to rotate, thus causing wafer damage.

[0077] For example, multiple peripheral cleaning structures 500 are provided, and each of the supporting structures 100 is provided with a peripheral cleaning structure 500.

[0078] For example, one circumferential cleaning structure 500 is provided, and the circumferential cleaning structure 500 is provided on any supporting structure 100.

[0079] Specifically, the peripheral cleaning structure 500 includes a passive wheel 510 and a sponge brush 520. The passive wheel 510 is rotatably mounted on the bearing structure 100, and the sponge brush 520 is sleeved on the passive wheel 510. The sponge brush 520 is pressed onto the peripheral surface of the wafer for rolling and brushing.

[0080] Furthermore, combined Figure 6The wafer cleaning apparatus also includes an adjustment structure 600 disposed on the support structure 100. The adjustment structure 600 is used to adjust the position of the passive wheel 510 so that the sponge brush 520 on the passive wheel 510 can better fit the wafer circumference and clean it, thereby reducing the poor cleaning effect caused by the same processing error as the roller brush 200 and the cumulative error formed when the sponge brush 520 is cleaning the wafer.

[0081] Specifically, the adjustment structure 600 includes a base 610 movably disposed on the support structure 100, a passive wheel 510 disposed on the base 610, and the base 610 adjusts the distance between the passive wheel 510 and the wafer circumference by moving laterally relative to the support structure 100.

[0082] For example, the base 610 has a first cylinder 310, which adjusts the internal air pressure so that the sponge brush 520 is pressed onto the wafer circumference at a preset pressure range. Its control method is the same as that of the roller brush 200 described above, by dynamically adjusting the pressure applied by the sponge brush 520 to the wafer circumference in real time so that it can better clean the wafer circumference.

[0083] For example, a slide rail 613 is provided on the base 610 and a fastener 650 is provided in the slide rail 613. The driven wheel 510 is slidably disposed on the base 610 and is fixed by the fastener 650. When the fastener 650 is loosened, the position of the driven wheel 510 is adjusted. When the fastener 650 is tightened, the driven wheel 510 is fixed.

[0084] Furthermore, the passive wheel 510 can be driven directly by a motor or by a transmission drive of the bearing structure 100 to optimize the overall structure of the cleaning device.

[0085] For example, the passive wheel 510 is directly driven by a motor.

[0086] For example, the passive wheel 510 is driven by the support structure 100. Specifically, the circumferential cleaning structure 500 of the support structure 100 also includes an idler wheel 540, through which the passive wheel 510 is connected to the support structure 100 (specifically the driving wheel 140) via the idler wheel 540.

[0087] The drive wheel 140 is directly driven by a motor, which drives the wafer pedestal 120 to rotate. The idler wheel 540 is located between the drive wheel 140 and the driven wheel 510, and is connected to the drive wheel 140 and the driven wheel 510 respectively.

[0088] A drive system is used to simultaneously move the support structure 100 and the peripheral cleaning structure 500 to optimize the structure of the wafer device, making it more compact and simple.

[0089] Since the driven wheel 510 needs to adjust its position in real time and needs to transmit power through a combination of the driving wheel 140 and the idler wheel 540, the adjustment structure 600 also includes an adjustment block 620 movably mounted on the base 610. The idler wheel 540 is mounted on the adjustment block 620. The adjustment block 620 adjusts the position of the idler wheel 540 by lateral movement and rotation relative to the base 610, so that the idler wheel 540 is connected to the driving wheel 140 and the driven wheel 510 respectively.

[0090] In one specific embodiment, the base 610 has a movable hole 611 and a fixed hole 612. A first adjusting shaft 630 is disposed in the movable hole 611, and a second adjusting shaft 640 is disposed in the fixed hole 612. The first adjusting shaft 630 and the second adjusting shaft 640 are connected by a screw passing through both. The adjusting block 620 rotates relative to the base 610 about the fixed hole 612 as its axis, and moves laterally relative to the base 610 about the opening direction of the movable hole 611. After the position of the idler wheel 540 is adjusted, the first adjusting shaft 630 and the second adjusting shaft 640 are tightened to fix the adjusting block 620 to the base 610.

[0091] The movement trajectory of the idler wheel 540 is as follows: Figure 6 As shown by the dashed line.

[0092] Furthermore, referring to Figure 7 Spray structures 700 are provided on both the upper and lower sides of the wafer bearing surface 110. The spray structures 700 clean the wafer by spraying liquid in conjunction with roller brushes 200 and sponge brushes 520, rinsing away dust from the wafer surface. In a specific embodiment, the roller brushes 200 and sponge brushes 520 store deionized water, and the spray structures 700 further spray ammonia and deionized water onto the wafer surface to clean it.

[0093] It should be noted that this embodiment does not specifically limit the form of the spraying structure 700.

[0094] For example, the spray structure 700 located above the wafer support surface 110 is configured as a plurality of fluid nozzles 710.

[0095] For example, the spraying structure 700 located below the wafer support surface 110 is configured as a spray pipe 720, and the spray pipe 720 has a plurality of liquid outlet holes along its own length direction.

[0096] Example 2: This embodiment 2 discloses a wafer cleaning method, which uses the above-mentioned wafer cleaning apparatus. The wafer cleaning method includes the following steps: S100, The wafer to be cleaned is transported to the wafer support surface 110 and the wafer is clamped.

[0097] S200 causes the wafer to rotate.

[0098] S300 outputs cleaning fluid to the surface of the wafer to wet and pre-clean it.

[0099] S400, move the roller brushes 200 on the upper and lower sides of the wafer until they contact the wafer surface, adjust the pressure of the upper and lower roller brushes 220 pressing against the wafer surface to the preset pressure range, so that the roller brushes 200 clean the upper and lower surfaces of the wafer.

[0100] The process of adjusting the pressure of the upper and lower roller brushes 200 pressing onto the wafer surface to a preset pressure range includes the following steps: Based on the force balance model constructed using roller brush 200: F 推 =F 阻 +F 辊刷-晶圆 Among them, F 推 The thrust F applied by the force-applying structure 300 to the roller brush 200 阻 F represents the resistance force experienced by the force-applying structure 300 when it moves. 辊刷-晶圆 The F is the pressure exerted on the wafer when it is pressed by the roller brush 200. 辊刷-晶圆 It is positively correlated with the actual compression of the roller brush 200.

[0101] Based on the force-applying structure being designed as a low-friction cylinder. Where D1 is the cylinder diameter, D2 is the shaft diameter, and P is the air pressure.

[0102] Taking the roller brush 210 as an example, it is further provided with an elastic element 330, F 阻 This includes the roller brush 200 needing to overcome the preload F of the elastic element 330 during compression. 预压1 The elastic force F generated when the elastic element 330 is compressed 弹 The frictional force F that a low-friction cylinder needs to overcome when moving. f The pre-force F that a low-friction cylinder needs to overcome when moving. 预压2 .

[0103] That is, F 阻 =F 预压1 +F 预压2 +F 弹 +F f The frictional force F that a low-friction cylinder needs to overcome when moving. f The preload F that needs to be overcome when the low-friction cylinder moves. 预压2 The value of is small and can be ignored or set as a constant. For example, in this embodiment, F is... f F 预压1 F 预压2 The sum is simplified to a constant M, and the simplified force equilibrium model yields the following equation: F 推 =F 弹 +F 辊刷-晶圆 +M Where F_elastic = KX, K is the elastic coefficient of elastic element 330, and X is the deformation of elastic element 330.

[0104] F is determined based on the theoretical compression of roller brush 200. 辊刷-晶圆 The range of values ​​for the preset pressure range is defined. It should be noted that the specific values ​​for the preset pressure range have already been described in detail, and will not be repeated here.

[0105] The displacement of the roller brush 200 is measured and the actual compression of the roller brush 200 is obtained. Based on the actual compression of the roller brush 200, the thrust applied to the roller brush 200 by the force-applying structure 300 is adjusted.

[0106] As shown in the above formula, the thrust applied by the force-applying structure 300 to the roller brush 200 needs to be dynamically adjusted according to the deformation of the roller brush 200 and the elastic element 330. Specifically, this involves adjusting the air pressure of the low-friction cylinder. For the upper roller brush, in actual operation, the above force balance model is entered into the corresponding control system. Furthermore, the magnitude of the force corresponding to the roller brush 200 and the elastic element 330 is measured and entered into the control system through displacement measurement or pressure measurement (e.g., displacement sensor, pressure sensor). The air pressure adjustment scheme of the low-friction cylinder is then output to achieve real-time dynamic control of the pressure applied by the roller brush 200 and maintain it within the preset pressure range.

[0107] It should also be noted that for the lower roller brush 220, which does not have an elastic element 330 and adopts a direct pull method, the corresponding force balance model can eliminate F. 弹 The settings.

[0108] S500, wafer cleaning completed, wafer obtained.

[0109] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A wafer cleaning apparatus, characterized in that, include: Multiple sets of support structures (100) have wafer support surfaces (110) that support the edge portion of the wafer, and the multiple sets of support structures (100) rotate to drive the wafer to rotate. A pair of roller brushes (200) are arranged opposite to each other on the upper and lower sides of the wafer support surface (110). The roller brushes (200) press against the wafer surface and roll and brush it when the wafer rotates. A pair of force-applying structures (300) are provided in a one-to-one correspondence with the pair of roller brushes (200); A control structure (400) is connected to a pair of force-applying mechanisms (300). The control structure (400) presets a pressure range and detects the pressure applied to the wafer by the roller brush (200). Based on the magnitude of the pressure relative to the preset pressure range, the control structure (300) drives the corresponding roller brush (200) to move up and down relative to the wafer, so that the roller brush (200) applies and maintains the pressure within the preset pressure range when it rolls and brushes the wafer.

2. The wafer cleaning apparatus according to claim 1, characterized in that, The preset pressure range is determined based on the compression amount of the roller brush (200), and includes: Obtain the compression amount of the roller brush (200); Based on the compression of the roller brush (200), a theoretical pressure value is determined, wherein the theoretical pressure value is positively correlated with the compression of the roller brush (200); Based on the theoretical pressure value, determine the minimum and maximum pressure values ​​of the preset pressure range to obtain the preset pressure range.

3. The wafer cleaning apparatus according to claim 2, characterized in that, The force-applying structure (300) includes a first cylinder (310), which is connected to and drives the corresponding roller brush (200) to move. When the first cylinder (310) adjusts the internal air pressure to press the roller brush (200) onto the wafer, the roller brush (200) applies pressure to the wafer and maintains pressure within a preset pressure range; and The force-applying structure (300) further includes a second cylinder (320) with a higher moving speed than the first cylinder (310). The second cylinder (320) is connected to the corresponding roller brush (200) and drives the roller brush (320) to contact the wafer surface.

4. The wafer cleaning apparatus according to claim 3, characterized in that, The force-applying structure (300) also includes an elastic element (330), the two ends of which are respectively connected to the first cylinder (310) and its corresponding roller brush (200).

5. A wafer cleaning apparatus according to claim 3, characterized in that, It also includes a control structure (400) connected to the first cylinder (310), which includes: A pressure sensor that acquires the actual pressure applied to the wafer by the roller brush (200); The controller, which is electrically connected to the first cylinder (310), adjusts the internal air pressure of the first cylinder (310) according to the difference between the actual pressure and the theoretical pressure, wherein the rate of adjustment of the internal air pressure of the first cylinder (310) is positively correlated with the difference between the actual pressure and the theoretical pressure.

6. The wafer cleaning apparatus according to claim 1, characterized in that, The supporting structure (100) is provided with a peripheral cleaning structure (500), the peripheral cleaning structure (500) includes: A passive wheel (510) is rotatably mounted on the bearing structure (100); A sponge brush (520) is fitted onto the passive wheel (510) and is pressed against the circumferential surface of the wafer for rolling and brushing.

7. A wafer cleaning apparatus according to claim 6, characterized in that, It also includes an adjustment structure (600), which is disposed on the periphery of the bearing structure (100) and the passive wheel (510) is rotatably disposed thereon. The adjustment structure (600) drives the passive wheel (510) to move, so that the sponge brush (520) is pressed onto the wafer at a preset pressure range when cleaning the wafer.

8. A wafer cleaning apparatus according to claim 7, characterized in that, The peripheral cleaning structure (500) also includes an idler wheel (540), and the passive wheel (510) is connected to the bearing structure (100) through the idler wheel (540). The adjustment structure (600) includes: A base (610) is provided with the passive wheel (510). The base (610) is provided on the bearing structure (100). The passive wheel (510) moves laterally relative to the base (610) to adjust its distance from the circumferential surface of the wafer. An adjusting block (620) is provided with the idler wheel (540). The adjusting block (620) is movably disposed on the base (610). The position of the idler wheel (540) is adjusted by lateral movement and rotation relative to the base (610), so that the idler wheel (540) is connected to the bearing structure (100) and the driven wheel (510) respectively.

9. A wafer cleaning method, characterized in that, The wafer cleaning apparatus according to any one of claims 1-8, the cleaning method includes the following steps: S100, The wafer to be cleaned is transported to the wafer support surface (110) and the wafer is clamped; S200, causes the wafer to rotate; S300: Output cleaning fluid to the surface of the wafer to wet and pre-clean the wafer; S400, Move the roller brushes (200) on the upper and lower sides of the wafer until they contact the wafer surface, and adjust the pressure of the upper and lower roller brushes (220) pressing against the wafer surface to the preset pressure range so that the roller brushes (200) clean the upper and lower surfaces of the wafer. S500, wafer cleaning completed, wafer obtained.

10. A wafer cleaning method according to claim 9, characterized in that, Adjusting the pressure of the upper and lower roller brushes (200) pressing against the wafer surface to a preset pressure range includes the following steps: Construct a force balance model based on the roller brush (200): F 推 =F 阻 +F 辊刷-晶圆 ; Among them, F 推 The thrust applied to the roller brush (200) by the force-applying structure (300), F 阻 F represents the resistance force experienced by the force-applying structure (300) during its movement. 辊刷-晶圆 The F is the pressure exerted on the wafer when it is pressed by the roller brush (200). 辊刷-晶圆 It is positively correlated with the actual compression of the roller brush (200); F is determined based on the theoretical compression of the roller brush (200). 辊刷-晶圆 The range of values ​​for the preset pressure range is determined; The displacement of the roller brush (200) is measured and the actual compression of the roller brush (200) is obtained. The thrust applied to the roller brush (200) by the force-applying structure (300) is adjusted based on the actual compression of the roller brush (200).

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