A silicon wafer washing device

Abstract

This invention discloses a silicon wafer cleaning device, comprising a motor, a rotating base, a protective shell, a support platform, at least two brush mechanisms, and a transmission mechanism. The motor output shaft is connected to the rotating base, and the support platform is mounted on the rotating base. The brush mechanisms, mounted on the support platform, include brush rollers and brush shafts. The transmission mechanism is located within the rotating base, simultaneously transmitting the motor torque to the rotating base and the brush shafts, achieving a combined motion of the support platform's revolution and the brushes' rotation under single-motor drive. The improvement lies in the inclusion of a pressure regulating component for real-time detection and precise adjustment of the contact pressure between the brush rollers and the wafer surface; and an electrostatic elimination component for neutralizing the electrostatic charge generated during the cleaning process. Preferably, a temperature control channel is also provided within the support platform. This invention features a compact structure and low cost. By introducing closed-loop pressure control and electrostatic elimination functions, it achieves efficient, precise, and non-destructive cleaning of wafers, making it particularly suitable for integration into a thinning machine for in-situ cleaning.

Description

Technical Field

[0001] This invention relates to the field of semiconductor processing equipment technology, and in particular to a silicon wafer cleaning device, specifically a cleaning mechanism for cleaning silicon wafers, especially silicon carbide wafers. More specifically, this invention relates to a compact silicon wafer cleaning mechanism driven by a single motor, capable of simultaneously realizing the rotation of the brush mechanism and the revolution of the support platform. Background Technology

[0002] In semiconductor chip manufacturing, the cleanliness of the silicon wafer surface, as the substrate material, directly determines the quality of subsequent processes such as photolithography, etching, and deposition, as well as the yield of the final chip. Any tiny particles, organic residues, or metal ion contamination can lead to short circuits, open circuits, or performance degradation, causing significant economic losses. Therefore, wafer cleaning is one of the most frequently repeated and critical process steps in semiconductor manufacturing.

[0003] With the development of semiconductor technology, especially the widespread application of third-generation semiconductor materials such as silicon carbide (SiC), wafer processing faces new challenges. Silicon carbide wafers are characterized by high hardness and good chemical stability, and their processing technology differs from that of traditional silicon wafers. For example, after the laser lift-off process of silicon carbide wafers, a layer of dust-like contaminants composed of grain particles remains on the front side of the wafer. These particles are small in size and have a strong adhesion to the wafer surface. If they are not effectively removed, they will become new sources of contamination during subsequent grinding, polishing, and other mechanical processing, leading to surface scratches, increased breakage rates, and severely impacting product yield and production efficiency.

[0004] Currently, the industry typically uses dedicated single-wafer cleaning machines or batch cleaning machines for wafer cleaning. These devices integrate sophisticated robotic arms, multiple cleaning modules (such as brushing, megasonic cleaning, rotary spraying, and drying), and precision control systems. However, these dedicated cleaning devices have the following significant drawbacks: High equipment costs: A fully functional dedicated cleaning machine can easily cost millions or even tens of millions of yuan, which is a huge capital expenditure for wafer manufacturing companies, especially small and medium-sized enterprises or research institutions.

[0005] Large space requirements: Specialized cleaning machines are typically bulky and require valuable cleanroom space. In the space-constrained environment of wafer fabs, adding new equipment often means modifying the existing factory layout, further increasing costs and complexity.

[0006] Low process integration: In certain process steps, such as the intermediate step after laser lift-off of silicon carbide wafers and before formal grinding, only a simple and quick surface particle removal operation is needed to protect the subsequent grinding equipment. Introducing a complex and expensive dedicated cleaning machine in this case is overkill, neither economical nor efficient. The wafers need to be transferred between different devices, increasing the risk of contamination and processing time.

[0007] Functional redundancy: Specialized cleaning machines often include multiple cleaning functions for various contaminants. However, for the single requirement of removing particulate dust generated in a specific process, these functions are redundant, resulting in a waste of equipment resources.

[0008] To address these issues, the industry has begun seeking solutions that integrate cleaning functions into other process equipment. For example, integrating the cleaning mechanism into a thinning machine (grinding equipment) utilizes the available space within the machine to achieve "instant cleaning" or "pre-grinding cleaning" process integration. This requires designing a compact, easy-to-control, and reliable wafer brushing mechanism within a limited, often cramped, space.

[0009] In existing technologies, some integrated brushing mechanisms often employ multiple motors to drive the rotation of the brush rollers and the revolution of the worktable carrying the wafers to be cleaned. While this approach offers independent control, it suffers from a complex structure, requiring separate motors, transmission components, control circuits, and cooling pipes for each motion, resulting in a significant space requirement and failing to meet the requirements for integration into a compact space. Furthermore, multi-motor systems increase the complexity of the control system and potential points of failure, leading to relatively high costs. Controlling the brushing pressure often relies on passive components such as springs, making real-time and precise adjustments impossible based on the degree of contamination and material of the wafer surface, potentially resulting in incomplete cleaning or wafer damage. Additionally, if the static charge generated by the friction between the brush bristles and the wafer during cleaning is not promptly dissipated, it can attract airborne particles, causing secondary contamination.

[0010] Therefore, developing a brushing device that is compact, occupies little space, is low in cost, is simple to control, and can accurately control the brushing pressure, effectively eliminate static electricity, and efficiently remove particles from the wafer surface has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0011] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a silicon wafer brushing device, which is a novel and compact silicon wafer brushing device that can realize the rotation of the brush mechanism and the revolution of the support platform simultaneously by a single motor. It is also a silicon wafer brushing device that can accurately control and optimize the process parameters during the brushing process.

[0012] The main objective of this invention is to overcome the shortcomings of existing cleaning equipment, such as high cost and large space occupation, and to provide an economical and efficient wafer surface cleaning solution that can be integrated into other processing equipment (such as thinning machines).

[0013] Another objective of this invention is to provide a wafer surface cleaning solution that is simple to control, has good cleaning effect, can adaptively adjust the cleaning pressure according to process requirements, and can effectively prevent the accumulation of static electricity.

[0014] The above-mentioned objective of this invention is achieved through the following technical solutions: This invention provides a silicon wafer cleaning device, comprising: a motor; a revolving base mounted on the output shaft of the motor; a protective shell disposed on the outside of the revolving base; a support platform mounted on the revolving base for supporting the silicon wafer to be cleaned; at least two brush mechanisms mounted on the support platform for cleaning the silicon wafer; and a transmission mechanism disposed inside the revolving base and respectively connected to the output shaft of the motor and the brush mechanisms; wherein, the motor drives the output shaft to rotate, thereby causing the revolving base and the support platform thereon to revolve relative to the protective shell; simultaneously, the output shaft of the motor transmits torque to the at least two brush mechanisms through the transmission mechanism, driving each brush mechanism to rotate around its own axis; each brush mechanism includes a brush roller, a brush shaft, and two bases detachably fixed to the support platform; the brush roller is fixedly sleeved on the brush shaft, and both ends of the brush shaft are rotatably supported on the two bases by bearings.

[0015] According to one embodiment of the present invention, the brush mechanism further includes a pressure regulating component connected to the brush shaft for adjusting the contact pressure between the brush roller and the silicon wafer surface.

[0016] According to one embodiment of the present invention, the pressure regulating assembly includes an elastic element and a pressure sensor; the elastic element is sleeved on one end of the brush shaft and abuts against the base and the brush roller to provide basic pressure preload; the pressure sensor is installed between the base and the bearing at the other end of the brush shaft to detect the pressure of the brush roller on the wafer surface in real time and generate a pressure signal; it also includes a controller, which receives the signal from the pressure sensor and changes the contact pressure of the brush roller on the wafer surface by adjusting the speed of the motor or an independent fine-tuning driver according to a preset pressure threshold.

[0017] According to one embodiment of the present invention, the device further includes an electrostatic elimination component comprising one or more ion generators and at least one ion nozzle disposed inside the protective housing and facing the silicon wafer surface on the support stage and / or the brush roller, for neutralizing the electrostatic charge generated during the brushing process.

[0018] According to one embodiment of the present invention, the ion generator is a high-voltage ionization type or a soft X-ray ionization type, and the electrostatic elimination component further includes at least one electrostatic sensor, which is disposed inside the protective shell and is used to detect the electrostatic potential on the surface of the silicon wafer and control the working state of the ion generator according to the detection result.

[0019] According to one embodiment of the present invention, the upper surface of the support platform is provided with a plurality of vacuum adsorption holes for adsorbing and fixing silicon wafers, and the support platform is also provided with at least one temperature control channel, wherein a heating or cooling medium is introduced into the temperature control channel to adjust the temperature of the silicon wafers during the brushing process.

[0020] According to one embodiment of the present invention, the bottom of the protective shell is provided with a waste liquid collection port and at least one exhaust port, the exhaust port being connected to an air extraction device for creating a negative pressure inside the protective shell to remove aerosols and particles generated during the brushing process.

[0021] According to one embodiment of the present invention, the transmission mechanism includes a fixed gear, at least one transmission gear, at least one gear shaft, at least two driving gears, at least two synchronous belts, and at least two driven gears; the fixed gear is fixedly mounted on the output shaft of the motor; the transmission gear and the driving gear are both fixed on the gear shaft, and the transmission gear and the fixed gear mesh with each other; the driven gears are respectively fixedly mounted on each of the brush shafts; each synchronous belt is respectively sleeved between a corresponding driving gear and a corresponding driven gear.

[0022] According to one embodiment of the present invention, a plurality of flexible brushes are uniformly fixedly connected to the outer wall of the brush roller.

[0023] According to one embodiment of the present invention, the motor is a servo motor or a stepper motor, and its speed is adjustable.

[0024] In summary, compared with the prior art, the present invention has at least one of the following beneficial technical effects: Compact structure and high space utilization: Through ingenious transmission mechanism design, only one motor is used as the power source to realize the self-rotation of the brush and the revolution of the support platform (driving the wafer). The structure is highly integrated and compact, making it suitable for installation inside equipment such as thinning machines.

[0025] Significantly reduces equipment costs: By eliminating multiple motors and their associated components, material and manufacturing costs are greatly reduced.

[0026] Simple control and high reliability: The control logic of a single motor is simple, which reduces the complexity of the control system and reduces potential failure points.

[0027] Excellent cleaning effect and high efficiency: The combined motion of the brush rotation and the platform revolution creates a cleaning trajectory similar to planetary motion, achieving uniform cleaning without dead angles, and is especially suitable for removing particulate dust remaining after laser stripping.

[0028] Highly adaptable to various processes and with adjustable speed: The motor speed is adjustable, and users can flexibly set the brush rotation speed and the bearing platform revolution speed according to process requirements.

[0029] Precise brushing pressure control: By introducing a pressure regulating component, the contact pressure between the brush and the wafer surface can be precisely controlled according to preset values ​​or real-time feedback, avoiding problems such as wafer damage due to excessive pressure or incomplete cleaning due to insufficient pressure, significantly improving process stability and yield.

[0030] Effectively prevents secondary electrostatic contamination: By integrating electrostatic elimination components, it can neutralize the electrostatic charge generated during the brushing process in real time, preventing secondary contamination of the wafer caused by electrostatic adsorption of particles, and is especially suitable for precision cleaning processes that are sensitive to electrostatics.

[0031] Enhancing process integration and intelligence: By introducing temperature control channels, brush sleeve detection sensors, and air extraction devices, the brush washing unit possesses more comprehensive process control capabilities and maintenance reminder functions, improving the equipment's automation level and operating efficiency. This addresses the client's new demands for refined and intelligent wafer surface treatment. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0033] Figure 2 This is a schematic diagram of the internal structure of the present invention.

[0034] Figure 3 This is a cross-sectional view of the present invention.

[0035] Reference numerals: 1. Motor; 11. Output shaft; 2. Revolution seat; 3. Protective shell; 4. Support platform; 5. Brush mechanism; 51. Brush roller; 511. Flexible brush; 52. Brush shaft; 53. Base; 54. Bearing; 6. Transmission mechanism; 61. Fixed gear; 62. Transmission gear; 63. Gear shaft; 64. Driving gear; 65. Synchronous belt; 66. Driven gear; 7. Silicon wafer. Detailed Implementation

[0036] The technical solutions in 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, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0037] In the description of this application, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0038] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0039] This invention discloses a silicon wafer brushing mechanism controlled by a single motor, comprising: One motor 1; A planetary mount 2 is installed on the output shaft 11 of motor 1; A protective shell 3 is disposed on the outside of the orbital seat 2; A support platform 4 is mounted on the orbital seat 2 to support the silicon wafer 7 to be cleaned; At least two brush mechanisms 5, mounted on the support platform 4, are used to brush the lower surface of the silicon wafer 7; and A transmission mechanism 6 is located inside the orbital seat 2 and is connected to the output shaft 11 of the motor 1 and the brush mechanism 5 respectively. Among them, the motor 1 drives the output shaft 11 to rotate, thereby causing the orbital seat 2 and the support platform 4 on it to revolve relative to the protective shell 3; at the same time, the output shaft 11 of the motor 1 transmits torque to at least two brush mechanisms 5 through the transmission mechanism 6, driving each brush mechanism 5 to rotate around its own axis, thereby brushing the lower surface of the silicon wafer 7 placed above the support platform 4.

[0040] Preferably, the brush mechanism 5 includes a brush roller 51, a brush shaft 52, and two bases 53 that are detachably fixed to the support platform 4; the brush roller 51 is fixedly sleeved on the brush shaft 52, and the two ends of the brush shaft 52 are rotatably supported on the two bases 53 by bearings 54 respectively.

[0041] As a significant improvement of this invention, the brush mechanism 5 further includes a pressure regulating component connected to the brush shaft 52 for adjusting the contact pressure between the brush roller 51 and the surface of the silicon wafer 7. In a preferred embodiment, the pressure regulating component includes an elastic element (such as a spring or disc spring) and a pressure sensor. The elastic element is sleeved on one end of the brush shaft 52 and abuts against the base 53 and the brush roller 51 to provide a basic pressure preload. The pressure sensor is installed between the base 53 and the bearing 54 at the other end of the brush shaft 52 to detect the actual working pressure of the brush roller 51 on the wafer surface in real time and generate a pressure signal. The device also includes a controller that receives the signal from the pressure sensor and, based on a preset optimal pressure threshold, precisely changes the contact pressure of the brush roller 51 on the wafer surface by adjusting the rotational speed of the motor 1 (changing the revolution and rotation speeds to change the contact pressure using centrifugal force) or by using an independent fine-tuning driver (such as a miniature linear motor or piezoelectric ceramic driver acting on one end of the brush shaft), thereby achieving closed-loop control.

[0042] As another important improvement of the present invention, the device also includes an electrostatic elimination component. The electrostatic elimination component includes one or more ion generators and at least one ion nozzle. The ion nozzle is disposed inside the protective housing 3 and faces the surface of the silicon wafer 7 on the support stage 4 and / or the brush roller 51, for spraying an ion gas stream onto them during the brushing process to neutralize the electrostatic charge generated by friction. The ion generator can be a high-voltage ionization type (generating ions through high-voltage corona discharge) or a soft X-ray ionization type (ionizing air through soft X-rays), the latter being safer and suitable for use in precision equipment. To more precisely control the electrostatic elimination effect, the electrostatic elimination component also includes at least one electrostatic sensor, disposed inside the protective housing 3, for real-time detection of the electrostatic potential on the surface of the silicon wafer 7 and feeding the signal back to the controller 9. The controller 9 controls the start / stop of the ion generator or the ion output intensity based on the feedback.

[0043] Preferably, the upper surface of the support stage 4 is provided with multiple vacuum adsorption holes for adsorbing and fixing the silicon wafer 7. Simultaneously, in order to control the wafer temperature during the brushing process (for example, some cleaning solutions need to achieve optimal results at specific temperatures, or to prevent wafer deformation due to frictional heat), the support stage 4 is also provided with at least one temperature control channel. This temperature control channel can be connected to an external temperature control unit via a rotary joint (not shown), and a heating or cooling medium (such as constant-temperature circulating water or oil) can be introduced inside to regulate the temperature of the silicon wafer 7 during the brushing process.

[0044] Furthermore, to prevent the back side of the wafer (non-brushed side) from being scratched by particles on the upper surface of the stage 4 during vacuum adsorption and rotation, the upper surface of the stage 4 is also provided with multiple microbumps of uniform height. These microbumps can be made of ceramic or wear-resistant plastic, and they form point contact with the back side of the wafer, greatly reducing the contact area and friction, and effectively protecting the back side of the wafer.

[0045] Preferably, a plurality of flexible brushes 511 are uniformly fixedly connected to the outer wall of the brush roller 51. The flexible brushes 511 are made of PVA (polyvinyl alcohol) sponge or antistatic brush material and are consumables. To facilitate maintenance and ensure cleaning quality, the device also includes a flexible brush detection sensor (not shown), which can be an optical sensor or a capacitive sensor, used to detect the wear degree or contamination state of the flexible brushes 511. When the flexible brushes 511 are detected to have reached their wear limit or are severely contaminated, the controller 9 will issue a replacement prompt signal on the human-machine interface.

[0046] Preferably, a waste liquid collection port is provided at the bottom of the protective shell 3. Simultaneously, to prevent the escape or redeposition of mist (aerosol) containing fine particles generated during the washing process onto the wafer, at least one exhaust port is provided on the top or side wall of the protective shell 3. The exhaust port is connected to an extraction device (such as a plant ventilation system) to create a slight negative pressure inside the protective shell 3, promptly removing the generated aerosols and light particles and sending them to the waste gas and waste liquid treatment system.

[0047] Preferably, the transmission mechanism 6 includes a fixed gear 61, at least one transmission gear 62, a gear shaft 63, at least two driving gears 64, at least two synchronous belts 65, and at least two driven gears 66. The fixed gear 61 is fixedly mounted on the output shaft 11 of the motor 1. The transmission gear 62 and the driving gear 64 are both fixed on the gear shaft 63, and the transmission gear 62 meshes with the fixed gear 61. The driven gears 66 are respectively fixedly mounted on each brush shaft 52. Each synchronous belt 65 is respectively sleeved between a corresponding driving gear 64 and a corresponding driven gear 66. This transmission scheme ensures smooth and precise power transmission.

[0048] Preferably, motor 1 is a servo motor or a torque motor with torque control function, whose speed and torque are adjustable to achieve independent or correlated adjustment of the revolution speed and rotation speed, thereby cooperating with the pressure regulating component to achieve the optimal brushing process. This brushing device is particularly suitable for integration into the interior of a thinning machine or grinding machine for in-situ brushing of wafers before grinding. Example

[0049] Please refer to the following: Figure 1 , Figure 2 and Figure 3 The first embodiment of the present invention provides a silicon wafer cleaning device. This device is mainly used to clean the lower surface of a silicon wafer 7 during semiconductor processing, and is particularly suitable for particle removal processes of silicon carbide wafers after laser lift-off and before grinding.

[0050] like Figure 1 As shown, the brushing mechanism mainly includes: a motor 1, a revolving seat 2, a protective shell 3, a support platform 4, at least two brush mechanisms 5, a transmission mechanism 6, a pressure regulating component, a static elimination component, a controller, and other auxiliary components.

[0051] Motor 1 is the sole power source for the entire mechanism. Motor 1 has one output shaft 11. The center of the orbital seat 2 is fixedly connected to the output shaft 11 of motor 1. Protective shell 3 is fixedly mounted on the housing of motor 1 and remains stationary. Support platform 4 is fixedly mounted on orbital seat 2. Brush mechanism 5 is mounted on support platform 4. Transmission mechanism 6 is located inside orbital seat 2.

[0052] The orbital seat 2 is a rigid component that is roughly cylindrical or disc-shaped, and its center is fixedly connected to the output shaft 11 of the motor 1. When the motor 1 is working, the rotation of the output shaft 11 directly drives the orbital seat 2 to rotate around the axis of the output shaft 11, which is called "revolution".

[0053] The protective shell 3 has a cylindrical structure with a central hole at the bottom for the output shaft 11 of the motor 1 to pass through. The protective shell 3 is fixedly mounted on the housing of the motor 1 or other fixed base (such as the frame of a thinning machine) and remains stationary. The orbital seat 2, the support platform 4 (described later), and most of the brush mechanism 5 are housed within the internal space of the protective shell 3. The protective shell 3 serves to: 1) prevent the cleaning fluid used during the cleaning process from splashing to the outside and contaminating the internal environment of the equipment; 2) collect waste liquid and particles generated during brushing; and 3) provide safety protection for the high-speed rotating components inside. The upper surface of the protective shell 3 is preferably substantially flush with or slightly lower than the upper surface of the support platform 4 to avoid interference with the handling of the wafers.

[0054] The support platform 4 is fixedly mounted on the orbital base 2 and revolves with it. The upper surface of the support platform 4 is used to place and fix the silicon wafer 7 to be cleaned. To firmly fix the wafer during high-speed rotation, the upper surface of the support platform 4 is usually provided with multiple vacuum adsorption holes. These vacuum adsorption holes are connected to an air passage (not shown) located in the center of the orbital base 2 or even the motor output shaft 11 through internal channels, and finally connected to an external vacuum source (not shown). When it is necessary to fix the wafer, the vacuum is turned on, and the wafer is firmly adsorbed on the support platform 4. After cleaning, the vacuum is released, and the wafer can be easily removed.

[0055] The brush mechanism 5 is used to physically clean the lower surface of the wafer. In this embodiment, there are two brush mechanisms 5, which are mounted symmetrically or asymmetrically on the support platform 4. Each brush mechanism 5 specifically includes: a brush roller 51, a brush shaft 52, two bases 53, and two bearings 54.

[0056] The brush roller 51 is cylindrical, with multiple flexible brushes 511 evenly fixed to its outer wall. The choice of material for the flexible brushes 511 is crucial, ensuring that they will not scratch or damage the delicate wafer surface during the cleaning process. Preferred materials include, but are not limited to: PVA (polyvinyl alcohol) sponge, high-purity antistatic nylon bristles, polyester bristles, or soft animal hair (such as camel hair). PVA sponge is often used for wafer cleaning due to its excellent water absorption and softness.

[0057] The brush shaft 52 is a slender, rigid shaft, and the brush roller 51 is fixedly fitted (e.g., by interference fit, key connection, or bonding) in the middle of the brush shaft 52. The two ends of the brush shaft 52 are rotatably supported on two bases 53 by bearings 54. The two bases 53 are detachably fixed to the support platform 4 by fasteners such as screws. This detachable structure allows the brush mechanism 5 to function as a single module, facilitating installation, replacement, and maintenance. When the brush roller 51 wears out and needs replacement, simply remove the base 53 to remove the old brush mechanism 5 entirely and replace it with a new one—very convenient.

[0058] The transmission mechanism 6 is the core of realizing "single motor controlled rotation plus revolution". It is cleverly set inside the revolution seat 2, making full use of the space. The transmission mechanism 6 is used to distribute the torque of the output shaft 11 of the motor 1 to the two brush mechanisms 5 while driving the revolution seat 2 to revolve, so that they drive them to "rotate" around their respective brush shaft 52 axes.

[0059] Combination Figure 2 The specific structure of the transmission mechanism 6 in this embodiment is described in detail. The transmission mechanism 6 mainly includes: a fixed gear 61, a transmission gear 62, a gear shaft 63, two driving gears 64, two synchronous belts 65, and two driven gears 66.

[0060] The fixed gear 61 is a gear with a central bore, which is fixedly mounted on the output shaft 11 of the motor 1, typically located below or inside the orbital seat 2. Importantly, the fixed gear 61 is circumferentially fixedly connected to the output shaft 11 (e.g., via a key), ensuring that the fixed gear 61 rotates synchronously with the output shaft 11. Since the orbital seat 2 is also fixedly connected to the output shaft 11, there is no relative rotation between the fixed gear 61 and the orbital seat 2; they revolve together as a single unit with the output shaft 11.

[0061] The transmission gear 62 and the two driving gears 64 are all fixedly mounted on the same gear shaft 63, forming a synchronously rotating gear assembly. This gear assembly is rotatably supported inside the orbital seat 2 by bearings (not shown). The transmission gear 62 is positioned to mesh with the fixed gear 61.

[0062] There are two driven gears 66, which are respectively fixedly installed at one end of the two brush shafts 52 in opposite directions (e.g., Figure 1 (The left end of the brush shaft 52 shown). Thus, the rotation of each driven gear 66 will directly drive the rotation of the brush shaft 52 and the brush roller 51 to which it is located.

[0063] Two synchronous belts 65 connect a driving gear 64 and a driven gear 66 respectively, forming a flexible transmission connection. The synchronous belts 65 have the advantages of accurate transmission, no slippage, vibration absorption, and no need for lubrication, making them very suitable for use in space-constrained applications requiring precise positioning.

[0064] The core improvement of this embodiment lies in the introduction of closed-loop pressure control and electrostatic elimination functions.

[0065] In each brush mechanism 5, the flexible brushes 511 of the brush roller 51 contact the wafer 7. One end of the brush shaft 52 is supported on a base 53 via a bearing 54, on which a pressure sensor is mounted. The other end of the brush shaft 52 is also supported on another base 53 via a bearing 54, and at this end, an elastic element (spring) is compressed between the end of the brush roller 51 and the base 53, providing an initial preload force to the brush roller 51 toward the wafer 7. The pressure value detected in real time by the pressure sensor is transmitted to the controller. The controller stores optimal pressure ranges set according to different wafer materials and process stages. When the detected pressure deviates from the set range, the controller adjusts the pressure back to the set value by adjusting the speed of the motor 1 or driving a fine-tuning actuator (not shown, which may be mounted on the base 53 for precisely pushing the brush shaft 52). For example, a higher pressure can be set in the coarse cleaning stage, and a lower pressure in the fine cleaning stage. This adaptive pressure adjustment function greatly improves the fineness and yield of the cleaning process.

[0066] Simultaneously, an electrostatic sensor monitors the electrostatic potential inside the protective casing 3 or on the surface of the wafer 7. Once the accumulated electrostatic charge exceeds a threshold, the controller immediately activates the ion generator, blowing positive and negative ions through ion nozzles onto the wafer 7 and the area of ​​the brush roller 51 to neutralize the charge and prevent particle adsorption. This function is particularly important for cleaning high-resistivity materials such as silicon carbide.

[0067] The working process and principle of the scrubbing mechanism in this embodiment are described in detail below: First, the silicon wafer 7 to be cleaned is placed on the upper surface of the support stage 4 by an external robotic arm (not shown), and a vacuum is turned on to firmly adsorb the wafer.

[0068] Next, start motor 1. The output shaft 11 of motor 1 begins to rotate at a preset speed.

[0069] The revolution motion is achieved as follows: The output shaft 11 directly drives the orbital seat 2, which is fixedly connected to it, to rotate. The rotation of the orbital seat 2, in turn, drives the support platform 4 on it and the two brush mechanisms 5 mounted on the support platform 4 to perform circular motion around the axis of the output shaft 11. This is the "revolution" of the support platform 4 (and the wafer on it) relative to the stationary protective shell 3. The revolution allows the brush mechanisms 5 to traverse the entire lower surface of the wafer.

[0070] The rotation is achieved as follows: Simultaneously, the rotation of the output shaft 11 also drives the fixed gear 61 on it to rotate synchronously. The fixed gear 61 drives the transmission gear 62 meshing with it to rotate. The rotation of the transmission gear 62 drives the gear shaft 63 coaxial with it and the two driving gears 64 at both ends of the gear shaft 63 to rotate together. The rotation of the two driving gears 64 transmits power to the two driven gears 66 through the synchronous belts 65 connected to them respectively. The rotation of the driven gears 66 ultimately drives the brush shaft 52 and the brush roller 51 fixed to it to rotate around their own axis. This is the "rotation" of the brush mechanism 5. The rotation enables the flexible brush 511 on the brush roller 51 to perform a brushing action on the wafer surface.

[0071] Under the combined effect of revolution and rotation, the two brush rollers 51, like planets, revolve around the center of the motor shaft while rotating at high speed around their own axes. The flexible brush 511 contacts the lower surface of the wafer 7, generating relative motion, thereby efficiently removing particulate contaminants from the wafer surface.

[0072] During the washing process, the cleaning fluid supply device (not shown) can be turned on to spray deionized water or chemical cleaning fluid onto the wafer surface or brush roller through nozzles to assist in cleaning and remove contaminants. The waste liquid and particles generated during washing are thrown against the inner wall of the protective shell 3 under centrifugal force and eventually flow into the waste liquid collection device at the bottom (not shown) for unified treatment.

[0073] After cleaning, motor 1 stops rotating, and the rotation of brush roller 51 and the revolution of support platform 4 also stop. The vacuum is turned off, and the cleaned silicon wafer 7 is removed by a robotic arm and sent to the next process. Example

[0074] The main difference between this embodiment and the first embodiment lies in the specific layout of the transmission mechanism 6. In the first embodiment, a single gear shaft 63 drives both brush mechanisms 5 simultaneously. In this embodiment, two independent transmission branches are used.

[0075] Specifically, the transmission mechanism 6 includes a fixed gear 61, two transmission gears 62 (62a and 62b), two gear shafts 63 (63a and 63b), two driving gears 64 (64a and 64b), two synchronous belts 65, and two driven gears 66.

[0076] The fixed gear 61 remains fixed to the motor output shaft 11. Two transmission gears 62a and 62b are respectively fixedly mounted on two gear shafts 63a and 63b, and both transmission gears 62a and 62b mesh with the fixed gear 61. It is understandable that, since the fixed gear 61 meshes with two gears simultaneously, the gear arrangement can be appropriately designed to ensure the direction of rotation. One driving gear is fixed on each gear shaft 63 (64a is fixed on 63a, and 64b is fixed on 63b). Then, each driving gear drives a corresponding driven gear 66 via a synchronous belt 65.

[0077] This layout is more symmetrical in structure, with the drive chains of the two brush mechanisms completely independent and without interference. Although it increases the number of parts, it may offer greater flexibility in spatial arrangement. For example, when the two brush mechanisms need to be installed far apart, this can be achieved by adjusting the positions of the transmission gears 62 and gear shafts 63. The two transmission gears 62 rotate in opposite directions, which will cause the two brush rollers 51 to rotate in opposite directions as well. This may have different effects on the cleaning effect (e.g., producing brushing torques in the same or opposite directions), which the user can choose according to actual needs. Example

[0078] This embodiment discloses an application scenario in which the brushing mechanism of the present invention is integrated into a thinning machine.

[0079] A wafer thinning machine is a device used to grind the back side of a wafer to reduce its thickness. It typically includes a closed working chamber containing a wafer clamping stage for holding the wafer, a grinding spindle and grinding wheels mounted on it for grinding, and a robotic arm for moving the wafer.

[0080] In traditional thinning processes, especially for silicon carbide wafers that have undergone laser lift-off, the front side of the wafer is covered with a large amount of particulate dust. If the wafer is placed directly on a wafer chuck for back-side grinding, this dust may scratch the front side of the wafer under vacuum suction or mechanical pressure, or even contaminate the grinding area, leading to wafer breakage.

[0081] After laser lift-off of the silicon carbide wafer, the front side of the wafer is covered with a large amount of dust. The robotic arm first places wafer 7 (front side down) onto the support platform 4 of this brushing device within the working chamber of the thinning machine. During the brushing process, a constant temperature of 25°C deionized water is circulated through the temperature control channel within the support platform 4 to absorb frictional heat and maintain a stable wafer temperature. The pressure regulating component precisely controls the brush pressure at 0.5N. The electrostatic elimination component operates throughout the process, ensuring that the electrostatic potential on the wafer surface is below ±10V. After brushing, the waste liquid is discharged from the bottom collection port, and the generated mist is extracted from the top exhaust port. Subsequently, the robotic arm removes the cleaned wafer 7 and sends it to the wafer clamping stage for back grinding. The entire in-situ cleaning process is efficient, precise, and pollution-free.

[0082] In addition to the above embodiments, the present invention can have various modifications. For example, the number of brush mechanisms 5 can be more than two; the transmission method can also adopt gear or chain transmission; the ion generator 81 can also be integrated outside the protective shell 3.

[0083] This invention cleverly utilizes the unused corner space within the working chamber of the thinning machine to fix the washing mechanism therein. Its power, vacuum, and cleaning fluid interfaces are all connected to the main control system of the thinning machine.

[0084] For example, the number of brush mechanisms 5 is not limited to two. Depending on the wafer size and cleaning efficiency requirements, three, four, or more brush mechanisms can be provided. Accordingly, the transmission mechanism 6 also needs to be adapted, for example, by increasing the number of gear shafts, drive gears, timing belts, and driven gears.

[0085] For example, the transmission method is not limited to synchronous belt drive. In situations where space permits and noise and vibration requirements are not high, gear drive, chain drive, and other methods can also be used. For instance, a driving gear can be installed on the gear shaft 63, which directly meshes with the driven gear installed on the brush shaft 52, thus eliminating the need for a synchronous belt. However, this solution requires higher precision and positioning of the gears and is not as flexible as synchronous belt drive.

[0086] For example, the position and form of the fixed gear 61 can be varied. It does not necessarily have to be a single gear, but can also be a gear segment directly machined on the output shaft 11.

[0087] For example, an axial position adjustment mechanism can be installed on the brush shaft 52 to adjust the contact pressure between the brush roller 51 and the wafer surface, so as to adapt to wafers of different thicknesses or different cleaning intensity requirements. All the above modifications should be considered to fall within the protection scope of this invention.

[0088] The silicon wafer cleaning mechanism with single-motor control for rotation and revolution provided by this invention is compact, low-cost, easy to control, and provides excellent cleaning results. It is particularly suitable for achieving rapid and efficient cleaning of wafers within limited equipment space. It can be used as a standalone module, but is more preferably integrated into existing semiconductor processing equipment such as thinning machines, grinding machines, and inspection equipment to achieve in-situ treatment of wafer surfaces before and after specific process steps. By introducing intelligent and refined functions such as pressure closed-loop control, electrostatic elimination, temperature control, wear detection, and negative pressure extraction, the device significantly improves process control and cleaning effect while retaining the advantages of its compact structure and single power source. It is particularly suitable for solving the fine cleaning challenges in the processing of high-end semiconductor materials (such as silicon carbide), possessing extremely high industrial practical value and broad application prospects.

[0089] This organization has a significant effect on solving the dust removal problem after laser stripping of silicon carbide wafers, which can effectively improve product yield and production efficiency. It has extremely high industrial practical value and broad application prospects in the semiconductor manufacturing field.

[0090] The implementation principle of this invention is as follows: This invention discloses a silicon wafer 7 brushing mechanism controlled by a single motor with rotation and revolution, belonging to the field of semiconductor processing equipment technology. The mechanism includes a motor 1, a revolution base 2, a protective shell 3, a support platform 4, at least two brush mechanisms 5, and a transmission mechanism 6. The output shaft 11 of the motor 1 is connected to the revolution base 2, the revolution base 2 is externally protected by the protective shell 3, and the support platform 4 is mounted on the revolution base 2. The brush mechanism 5 is mounted on the support platform 4 and includes a brush roller 51 and a brush shaft 52. The transmission mechanism 6 is located inside the revolution base 2 and includes a fixed gear 61 fixed to the output shaft 11, a transmission gear 62 meshing with the fixed gear 61, a driving gear 64 coaxial with the transmission gear 62, a driven gear 66 fixed to the brush shaft 52, and a synchronous belt 65 connecting the driving gear 64 and the driven gear 66. The improvements include a pressure regulating component for precisely controlling the contact pressure between the brush roller 51 and the wafer 7; an electrostatic elimination component for neutralizing static electricity generated during brushing; a temperature control channel for regulating the temperature of the wafer 7; and an air extraction device for discharging contaminated mist. During operation, motor 1 drives the revolution base 2 and the support platform 4 to revolve, while simultaneously driving the brush shaft 52 and the brush roller 51 to rotate via a fixed gear 61, a transmission gear 62, a driving gear 64, a synchronous belt 65, and a driven gear 66. This achieves a combined revolution and rotation motion under the control of a single motor 1, efficiently brushing the wafer. This invention has a compact structure and low cost, making it particularly suitable for integration into equipment such as thinning machines to solve the problem of particle removal after laser stripping of silicon carbide wafers 7.

[0091] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A silicon wafer washing device, characterized in that, include: One motor (1); A revolving mount (2) is mounted on the output shaft (11) of the motor (1); A protective shell (3) is disposed on the outside of the orbital seat (2); A support platform (4) is installed on the orbital seat (2) to support the silicon wafer (7) to be brushed. At least two brush mechanisms (5) are mounted on the support platform (4) for brushing the silicon wafer (7); and A transmission mechanism (6) is disposed inside the orbital seat (2) and is connected to the output shaft (11) of the motor (1) and the brush mechanism (5) respectively. The motor (1) drives the output shaft (11) to rotate, thereby causing the orbital seat (2) and its support platform (4) to revolve relative to the protective shell (3); at the same time, the output shaft (11) of the motor (1) transmits torque to the at least two brush mechanisms (5) through the transmission mechanism (6), driving each brush mechanism (5) to rotate around its own axis. The brush mechanism (5) includes a brush roller (51), a brush shaft (52), and two bases (53) detachably fixed on the support platform (4); the brush roller (51) is fixedly sleeved on the brush shaft (52), and the two ends of the brush shaft (52) are rotatably supported on the two bases (53) by bearings (54).

2. The silicon wafer brushing device according to claim 1, characterized in that, The brush mechanism (5) also includes a pressure regulating component connected to the brush shaft (52) for adjusting the contact pressure between the brush roller (51) and the surface of the silicon wafer (7).

3. The silicon wafer brushing device according to claim 2, characterized in that, The pressure regulating assembly includes an elastic element and a pressure sensor; The elastic element is sleeved on one end of the brush shaft (52) and abuts between the base (53) and the brush roller (51) to provide basic pressure preload; The pressure sensor is installed between the base (53) and the bearing (54) at the other end of the brush shaft (52) to detect the pressure of the brush roller (51) on the wafer surface in real time and generate a pressure signal. It also includes a controller that receives the signal from the pressure sensor and, based on a preset pressure threshold, adjusts the rotational speed of the motor (1) or an independent fine-tuning driver to change the contact pressure of the brush roller (51) on the wafer surface.

4. The silicon wafer brushing device according to claim 1, characterized in that, The device also includes an electrostatic elimination component comprising one or more ion generators and at least one ion nozzle disposed inside the protective housing (3) and facing the surface of the silicon wafer (7) on the support platform (4) and / or the brush roller (51) for neutralizing the electrostatic charge generated during the brushing process.

5. A silicon wafer brushing device according to claim 4, characterized in that, The ion generator is a high-voltage ionization type or a soft X-ray ionization type. The electrostatic elimination component also includes at least one electrostatic sensor. The electrostatic sensor is set inside the protective shell (3) and is used to detect the electrostatic potential on the surface of the silicon wafer (7) and control the working state of the ion generator according to the detection result.

6. A silicon wafer brushing device according to claim 1, characterized in that, The upper surface of the support platform (4) is provided with a plurality of vacuum adsorption holes for adsorbing and fixing the silicon wafer (7), and the support platform (4) is also provided with at least one temperature control channel, through which a heating or cooling medium is introduced to adjust the temperature of the silicon wafer (7) during the brushing process.

7. A silicon wafer brushing device according to claim 1, characterized in that, The bottom of the protective shell (3) is provided with a waste liquid collection port and at least one exhaust port. The exhaust port is connected to an air extraction device to create a negative pressure inside the protective shell (3) to remove the aerosols and particles generated during the brushing process.

8. A silicon wafer brushing device according to claim 1, characterized in that, The transmission mechanism (6) includes a fixed gear (61), at least one transmission gear (62), at least one gear shaft (63), at least two driving gears (64), at least two synchronous belts (65), and at least two driven gears (66); the fixed gear (61) is fixedly mounted on the output shaft (11) of the motor (1); the transmission gear (62) and the driving gear (64) are both fixed on the gear shaft (63), and the transmission gear (62) and the fixed gear (61) mesh with each other; the driven gears (66) are respectively fixedly mounted on each of the brush shafts (52); each of the synchronous belts (65) is respectively sleeved between a corresponding driving gear (64) and a corresponding driven gear (66).

9. A silicon wafer brushing device according to claim 1, characterized in that, Multiple flexible brushes (511) are uniformly fixedly connected to the outer wall of the brush roller (51).

10. A silicon wafer brushing device according to any one of claims 1-9, characterized in that, The motor (1) is a servo motor or a stepper motor, and its speed is adjustable.

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