Wafer cleaning device and cleaning method

Abstract

The invention discloses a wafer cleaning device and a cleaning method, and relates to the technical field of semiconductor manufacturing, and the cleaning method comprises the following steps: S1, generating continuous overflow of medium-temperature liquid water in a cleaning fluid flow channel; s2, generating a controllable cavitation bubble flow in the liquid water; s3, introducing an auxiliary bubble flow, and stirring and mixing the cavitation bubble flow to form a mixed fluid containing dual-mode bubbles; s4, converting the mixed fluid into vertical laminar flow and guiding the vertical laminar flow to the surface of the wafer; s5, cleaning pollutants on the surface of the wafer in a grading manner by utilizing ultrasonic waves with different frequencies generated by collapse of dual-mode bubbles; and S6, pollutants are continuously discharged through overflow. The cavitation bubble flow and the auxiliary bubble flow are generated in the cleaning fluid flow channel, the dual-mode bubble fluid is formed through stirring and mixing, high-frequency ultrasonic waves are synchronously released by means of dual-mode bubble collapse to remove nano-particles, low-frequency ultrasonic waves are synchronously released to remove micro-particles, traditional multi-step cleaning is replaced with one-step cleaning, the wafer transfer damage risk is eliminated, and the wafer transfer efficiency is improved. And the cleaning period is greatly shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and in particular to a wafer cleaning device and a cleaning method. Background Art

[0002] In the field of semiconductor wafer manufacturing, surface cleaning after chemical mechanical polishing (CMP) is a key link affecting yield. Existing technologies face three difficult-to-reconcile contradictions: 1. Conflict between cleaning efficiency and effect: To remove micron-level polishing residues, low-frequency, high-power ultrasonic waves are required, but the strong cavitation effect can easily cause micro-damage to the wafer surface; For nano-scale particles, high-frequency weak ultrasonic waves need to be used instead, but when the energy is insufficient, chemical additives must be relied upon, introducing the risk of secondary contamination.

[0003] Multi-step switching significantly prolongs the process time, and frequent wafer transfers increase the probability of scratches.

[0004] 2. Dilemma of pollution source control: Metal ultrasonic vibrators (such as titanium alloys) release Fe during cavitation + / Ni + ions, contaminating high-purity silicon substrates; Non-metallic piezoelectric ceramic vibrators are fragile and expensive, making it difficult to meet mass production needs.

[0005] 3. Conflict between temperature sensitivity and energy efficiency: Low-temperature (<40°C) cleaning fluid can inhibit chemical reactions, but it greatly weakens the cavitation intensity and has a low nanoparticle removal rate; Although heating to >60°C increases cavitation activity, it accelerates the cross-linking and solidification of polishing liquid residues, making removal more difficult.

[0006] Therefore, achieving efficient removal of micron / nanoparticles, zero metal contamination, and zero wafer damage in a single physical cleaning process remains an unresolved technical challenge. Summary of the Invention

[0007] The purpose of the present invention is to provide a wafer cleaning device and cleaning method to solve the problems existing in the above-mentioned prior art. In a single physical cleaning process, the efficient removal of micron / nano particles can be simultaneously achieved without metal contamination and maintaining zero damage to the wafer.

[0008] To achieve the above object, the present invention provides the following solutions: A wafer cleaning method, characterized by comprising the following steps: S1 generates a continuous overflow of medium-temperature liquid water in the cleaning fluid flow channel; S2 generates a controllable cavitation bubble flow in the liquid water; S3 introduces an auxiliary bubble flow and stirs and mixes the cavitation bubble flow to form a mixed fluid containing dual-mode bubbles; S4. converting the mixed fluid into a vertical laminar flow directed toward the wafer surface; S5. Using dual-mode bubble collapse to generate ultrasonic waves of different frequencies to clean the wafer surface contaminants graded; S6. Continuous discharge of pollutants through overflow.

[0009] In an exemplary embodiment, step S2 includes: S201. Using a focused laser beam to irradiate liquid water; S202. Scan the laser focus in three dimensions using a galvanometer system to edit the cavitation bubble array flow within a preset three-dimensional space.

[0010] In an exemplary embodiment, step S3 includes: S301. Cavitation bubbles converge to the upper part of the liquid water flow by buoyancy; S302. Inert gas jets are injected tangentially to the convergence zone to drive stirring; S303 accelerates the diffusion of cavitation bubbles, inert gas bubbles and liquid water by annular stirring; S304. Static pressure is restored to form a uniform vertical laminar flow containing bubbles.

[0011] In an exemplary embodiment, the auxiliary bubble flow is an inert gas jet.

[0012] In an exemplary embodiment, in step S5: Assist bubble collapse to remove micron-sized particles; The collapse of cavitation bubbles removes nano-sized particles.

[0013] The present invention also provides a wafer cleaning device for implementing the above-mentioned cleaning method, characterized in that it includes: an overflow trough for receiving and directing cleaning fluid; a quartz glass tunnel in fluid communication with the overflow trough for forming a cleaning fluid flow channel; a medium-temperature fluid supply system for providing temperature-controlled liquid water to the quartz glass tunnel; a cavitation bubble generating assembly for controllably generating cavitation bubbles in the liquid water within the quartz glass tunnel; A stirring and mixing component is used to inject an auxiliary bubble flow and stir and mix to form a mixed fluid; A wafer positioning mechanism is provided in the overflow trough, downstream of the stirring and mixing assembly, and is used to vertically fix the wafer to be cleaned. The wafer positioning mechanism cooperates with the quartz glass tunnel to form a vertical laminar flow guide structure; The vertical laminar flow guiding structure is configured to enable the mixed fluid to form a vertical laminar flow flowing over the wafer surface.

[0014] In an exemplary embodiment, the quartz glass tunnel comprises: a horizontal section, wherein the cavitation bubble generating assembly generates cavitation bubbles within the horizontal section; The turning section is used to convert the horizontal flow of fluid into a vertical flow; The vertical section has a cross-sectional area that gradually increases from bottom to top, and is divided into a stirring start zone and a stirring acceleration zone from bottom to top.

[0015] In an exemplary embodiment, the cavitation bubble generating assembly includes: A laser generator for emitting a laser beam with a wavelength of 1047 nm or 1064 nm; The galvanometer system controls the laser focus to perform three-dimensional scanning in the liquid water in the quartz glass tunnel to form cavitation bubbles.

[0016] In an exemplary embodiment, the stirring and mixing assembly includes: An air pipe is used to connect with an inert gas source and extends to the inside of the quartz glass tunnel, with the end of the air pipe being sealed; The jet nozzles are arranged in a directionally arranged opening on the side wall of the trachea. The jet nozzles in the stirring starting zone are used to make the cavitation bubble flow diffuse laterally, and the jet nozzles in the stirring acceleration zone are used to make the cavitation bubble flow rotate annularly along the side wall of the stirring acceleration zone.

[0017] In an exemplary embodiment, the isopipe comprises: The tank body is used to accommodate the wafer positioning mechanism. The top of the tank body is provided with an overflow channel, and the overflow channel is connected to a drain pipe. The outer periphery of the tank body is provided with a water collection tank, and the drain pipe extends into the water collection tank. The bottom of the trough is provided with a through hole for allowing the quartz glass tunnel to pass through, a supporting portion for supporting the end flange of the quartz glass tunnel, and a pressing portion for pressing the end flange. The pressing portion contacts both the end flange and the supporting portion. A first seal is provided in the area where the pressing portion contacts the end flange, and a second seal is provided in the area where the pressing portion contacts the supporting portion. A first quick exhaust valve connected to the water collecting tank is provided at the bottom of the overflow tank, and at least two of the first quick exhaust valves are arranged on both sides of the bottom of the overflow tank along the extension direction of the wafer plane; A second quick exhaust valve is provided at the bottom of the quartz glass tunnel.

[0018] Compared with the prior art, the present invention has achieved the following technical effects: 1. By generating a cavitation bubble flow (high-frequency source) and an auxiliary bubble flow (low-frequency source) in the cleaning fluid flow channel, a dual-mode bubble fluid is formed by stirring and mixing. With the help of the dual-mode bubble collapse, high-frequency ultrasonic waves (>1MHz) are released to remove nanoparticles and low-frequency ultrasonic waves (<100kHz) are released to remove micron particles. This one-step method replaces the traditional multi-step cleaning, eliminates the risk of wafer transfer damage, and significantly shortens the cleaning cycle.

[0019] 2. The energy from the collapse of cavitation bubbles is transferred to the wafer surface through the fluid medium, replacing the ultrasonic waves generated by traditional metal ultrasonic vibrators, and completely eliminating Fe + / Ni + Ionic contamination.

[0020] 3. Vertical laminar flow ensures that dual-mode bubbles evenly cover the wafer surface, the collapse energy acts precisely on the contaminant interface, the wafer damage rate is extremely low, and the overflow discharge removes contaminants in real time, forming a "high-efficiency cleaning-zero pollution-zero damage" technical closed loop. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 A schematic structural diagram of a wafer cleaning device disclosed in a specific embodiment of the present invention; Figure 2 for Figure 1 A side sectional view of Figure 3 for Figure 1 A front sectional view of Figure 4 for Figure 1 Schematic diagram of the structure of the quartz glass tunnel; Figure 5 for Figure 2 Schematic diagram of the structure of the stirring and mixing component; Figure 6 Schematic diagram of the lateral diffusion of cavitation bubble flow in the stirring starting area; Figure 7 Schematic diagram of the accelerated rotation of cavitation bubble flow in the stirring acceleration zone; in: 0. Wafer; 1. Overflow trough; 101. Trough body; 102. Overflow channel; 103. Drain pipe; 104. Water collection trough; 105. Supporting part; 106. Pressing part; 109. First quick exhaust valve; 110. Static pressure recovery section; 111. Wafer in-position sensor; 112. Wafer positioning failure sensor; 113. Sensor waterproof cover; 2. Quartz glass tunnel; 201. Horizontal section; 202. Turning section; 203. Vertical section; 203a. Stirring start zone; 203b. Stirring acceleration zone; 204. End flange; 205. Second quick exhaust valve; 3. Medium-temperature fluid supply system; 301. Static pressure water supply pipe; 302. Overflow valve; 303. Air control valve; 304. Solenoid valve; 4. Cavitation bubble generation component; 401. Laser generator; 402. Laser scanning optical path; 5. Stirring and mixing assembly; 501. Trachea; 503. First trachea support; 504. Second trachea support; 505. Third trachea support; 6. Wafer positioning mechanism; 601. Wafer support frame; 602. Wafer limit block; 603. Current limiting structure; 604. Diversion tunnel. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. People familiar with this technology can easily understand other advantages and functions of the present invention from the contents disclosed in this specification. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] The purpose of the present invention is to provide a wafer cleaning device and cleaning method to solve the problems existing in the prior art. In a single physical cleaning process, efficient removal of micron / nanoparticles, no metal contamination, adaptive temperature control, and zero damage to the wafer can be simultaneously achieved.

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Example 1 This embodiment provides a wafer cleaning method, comprising the following steps: S1 generates a continuous overflow of medium-temperature liquid water in the cleaning fluid flow channel; Among them, the temperature range of medium-temperature clean liquid water is 50℃-70℃: When the water temperature is higher than 50°C, the thermal motion of water molecules is significantly intensified, reducing the surface tension and viscous resistance of liquid water, making it easier for the subsequently generated cavitation bubbles to collapse and release high-intensity shock waves. Setting the upper temperature limit to 70°C effectively prevents the polishing residue on the wafer 0 surface from solidifying or sintering due to high temperature, ensuring that the contaminants are in a loose state for subsequent removal. The continuous overflow state is maintained by the static pressure water replenishment system, forming a stable vertical laminar flow, providing a fluid dynamics basis for subsequent bubble mixing and collapse.

[0027] S2. Generating a controlled cavitation bubble flow in liquid water; Specifically include: S201 uses a focused laser beam to irradiate medium-temperature liquid water. The laser energy triggers the localized vaporization of liquid water molecules at the focal point, generating cavitation bubbles with a cross-sectional area of ​​0.1-10μm. This replaces traditional metal ultrasonic vibrating plates and avoids ion contamination. S202. The galvanometer system scans the laser focus in three dimensions, editing the cavitation bubble array flow within a preset three-dimensional space. The galvanometer system scans the laser focus in three dimensions, precisely editing the distribution density, size, and trajectory of the cavitation bubbles within the preset spatial coordinates, forming a cavitation bubble array flow with a specific spatial configuration. This technology overcomes the physical limitations of traditional ultrasonic vibrating plates and enables programmable control of cavitation location and intensity.

[0028] S3 introduces an auxiliary bubble flow and stirs and mixes the cavitation bubble flow to form a mixed fluid containing dual-mode bubbles; Specifically include: S301. Cavitation bubbles gather to the upper part of the liquid water flow by buoyancy; S302. Inert gas jets are injected tangentially to the convergence zone to drive stirring; S303 accelerates the diffusion of cavitation bubbles, inert gas bubbles and liquid water by annular stirring; S304. Static pressure is restored to form a uniform vertical laminar flow containing bubbles.

[0029] The auxiliary bubble flow is an inert gas jet, preferably nitrogen.

[0030] Due to the physical property that cavitation bubbles have a lower density than liquid water, cavitation bubbles naturally converge to the upper layer of the liquid flow due to buoyancy. When the fluid turns vertically, the converging cavitation bubble flow enters the stirring zone. Inert gas, such as nitrogen, is sprayed tangentially on both sides of the converging cavitation bubbles. The high-speed jet of inert gas simultaneously introduces auxiliary bubble flow and drives the cavitation bubble group to rotate and rise. During the rotation and rise, the cavitation bubbles and inert gas bubbles undergo intense shear, collision, and fusion, achieving microscopic mixing and diffusion of dual-mode bubbles and liquid water. After mixing, the fluid passes through the static pressure recovery section 110 to eliminate turbulence, forming a uniform, stable vertical laminar flow containing dual-mode bubbles, providing a carrier for graded cleaning.

[0031] S4. Converting the mixed fluid into a vertical laminar flow directed toward the surface of wafer 0; Multiple wafers 0 are arranged vertically above the static pressure recovery section 110, with gaps between them. This accelerates the mixed fluid and forms a laminar flow vertically across the front and back of the wafers 0. This laminar flow combines high directionality with low shear stress, ensuring that bubbles are evenly distributed and move close to the wafer 0 surface while preventing high flow rates from damaging the wafer 0 microstructure. By leveraging the synergistic effects of gravity and fluid dynamics, the energy of bubble collapse is concentrated on the interface where contaminants adhere.

[0032] S5. Using dual-mode bubble collapse to generate ultrasonic waves of different frequencies to grade and clean the wafer surface contaminants; Among them, auxiliary bubble collapse removes micron-sized particles; cavitation bubble collapse removes nano-sized particles.

[0033] When the dual-mode bubbles in the mixed laminar flow contact the wafer surface, they collapse. This physical mechanism produces a graded cleaning effect: The auxiliary bubble collapse generates a low-frequency, high-intensity shock wave (typically <100kHz), forming micron-sized microjets and shear forces that effectively remove strongly attached micron-sized polishing particles. Meanwhile, the laser cavitation bubble collapse excites a high-frequency stress wave (typically >1MHz). Through the high-frequency oscillation of the cavitation microjets and the localized high temperature and high pressure (up to 5000K, 1000atm), these waves desorb nanoscale molecular contaminants and destroy their surface binding energy. These two collapse modes complement each other in time and space, achieving synergistic removal of contaminants across the full range of sizes.

[0034] S6. Continuous discharge of pollutants through overflow; During the cleaning process, contaminants are continuously discharged through vertical laminar flow. The overflow trough ensures that the fluid renewal rate matches the contaminant load. This dynamic drainage mechanism prevents secondary deposition of stripped contaminants while maintaining fluid cleanliness in the cleaning area.

[0035] Example 2 This embodiment provides a wafer cleaning apparatus for implementing the cleaning method described in Example 1. The apparatus comprises an overflow tank 1, a quartz glass tunnel 2, a medium-temperature fluid supply system 3, a cavitation bubble generating assembly 4, a stirring and mixing assembly 5, and a wafer positioning mechanism 6. The overflow tank 1 serves as the primary space for cleaning wafer 0 and is used to accommodate and guide the cleaning fluid. The quartz glass tunnel 2 is fluidically connected to the overflow tank 1 to form a cleaning fluid flow path. The medium-temperature fluid supply system 3 is used to provide temperature-controlled liquid water to the quartz glass tunnel 2. The cavitation bubble generating assembly 4 is used to controllably generate cavitation bubbles in the liquid water within the quartz glass tunnel 2. The stirring and mixing assembly 5 is used to inject an auxiliary bubble flow and stir and mix the liquid water to form a mixed fluid. The wafer positioning mechanism 6 is disposed in the overflow tank 1, downstream of the stirring and mixing assembly 5, and is used to vertically secure the wafer 0 to be cleaned. The wafer positioning mechanism 6 and the quartz glass tunnel 2 cooperate to form a vertical laminar flow guide structure, which causes the mixed fluid to form a vertical laminar flow across the surface of the wafer 0, thereby cleaning contaminants from the surface of the wafer 0 in a graded manner.

[0036] Specifically, overflow tank 1 includes a tank body 101 for accommodating wafer 0 and wafer positioning mechanism 6. An overflow channel 102 is provided at the top of tank body 101, which is connected to a drain pipe 103. A water collection tank 104 is provided on the periphery of tank body 101, and drain pipe 103 extends into water collection tank 104. During the cleaning process, contaminants continuously overflow with vertical laminar flow and are discharged into water collection tank 104 through overflow channel 102 and drain pipe 103.

[0037] The bottom of the trough body 101 is provided with a through hole for allowing the quartz glass tunnel 2 to pass through, a supporting portion 105 for supporting the end flange 204 of the quartz glass tunnel 2, and a pressing portion 106 for pressing the end flange 204. The pressing portion 106 contacts both the end flange 204 and the supporting portion 105. A first seal is provided in the area where the pressing portion 106 contacts the end flange 204, and a second seal is provided in the area where the pressing portion 106 contacts the supporting portion 105.

[0038] The quartz glass tunnel 2 includes a horizontal section 201, a turning section 202, and a vertical section 203. The cavitation bubble generating assembly 4 generates cavitation bubbles within the horizontal section 201, while the turning section 202 is used to convert the horizontal flow of fluid into a vertical flow. The cross-sectional area of ​​the vertical section 203 gradually increases from bottom to top, and is divided into a stirring initiation zone 203a and a stirring acceleration zone 203b.

[0039] The medium-temperature fluid supply system 3 includes a temperature sensor and a heater, which are used to adjust the water temperature so that the liquid water temperature is precisely controlled at 50-70°C, and provide temperature-controlled liquid water to the quartz glass tunnel 2 through the static pressure water supply pipe 301.

[0040] The cavitation bubble generation assembly 4 includes a laser generator 401 and a galvanometer system integrated with the laser generator 401. The laser generator 401 extends into the interior of the quartz glass tunnel 2 via a laser scanning optical path 402. The laser generator 401 is configured to emit a laser beam with a wavelength of 1047 nm or 1064 nm. The galvanometer system is configured to control the laser focus to perform a three-dimensional scanning operation within the liquid water within the quartz glass tunnel 2, thereby forming cavitation bubbles.

[0041] The laser generator 401 emits near-infrared light at a wavelength selected within the near-infrared secondary absorption peak of liquid water (with the main peak at 3000 nm). This wavelength is offset from the optical absorption peak of the quartz glass tunnel 2. Quartz glass has a transmittance of >99% (absorption rate <0.1%) in this wavelength band, ensuring that energy is efficiently coupled to the liquid water rather than absorbed by the tunnel material, thus avoiding the risk of thermal damage.

[0042] The computer controls the galvanometer system to edit three-dimensional bubble arrays in the water flow, such as grids, spirals, etc.

[0043] The stirring and mixing assembly 5 includes an air pipe 501 and jet orifices. The air pipe 501 is connected to an inert gas source and extends into the interior of the quartz glass tunnel 2. The end of the air pipe 501 is sealed. The jet orifices are arranged in a directionally arranged opening on the side wall of the air pipe 501. The jet orifices in the stirring initiation zone 203a are used to diffuse the cavitation bubble flow throughout the stirring initiation zone 203a. The jet orifices in the stirring acceleration zone 203b are used to accelerate the cavitation bubble flow in a circular manner along the side wall of the stirring acceleration zone 203b.

[0044] Specifically, the air pipe 501 is introduced from the sidewall of the bottom of the tank body 101. A first air pipe support 503 is installed at the exit of the quartz glass tunnel 2. A second air pipe support 504 is installed at the junction of the stirring start zone 203a and the stirring acceleration zone 203b of the vertical section 203. A third air pipe support 505 is installed at the beginning of the stirring start zone 203a. After being introduced from the sidewall of the bottom of the tank body 101, the air pipe 501 extends from the exit of the quartz glass tunnel 2 into the interior of the quartz glass tunnel 2 and is sequentially mounted on the first air pipe support 503, the second air pipe support 504, and the third air pipe support 505.

[0045] Please refer to Figure 2 The cavitation bubble generating assembly 4 generates cavitation bubbles in the medium-temperature liquid water in the horizontal section 201 of the quartz glass tunnel 2, such as Figure 2 As shown by the middle arrow, the cavitation bubbles are naturally gathered to the upper layer of the liquid flow in the horizontal flow channel due to the buoyancy. When the fluid turns vertically through the turning section 202 of the quartz glass tunnel 2 and enters the vertical section 203, the converged cavitation bubble flow first enters Figure 2On the left side of the stirring start area 203a, the jet nozzle opened on the air pipe 501 mounted on the third air pipe bracket 505 sprays inert gas to impact the cavitation bubbles gathered on the left side of the stirring start area 203a to the right side, so as to diffuse the cavitation bubble flow to the entire stirring start area 203a. Figure 6 After diffusion, it continues to rise to the stirring acceleration zone 203b, and the jet nozzle opened on the air pipe 501 mounted on the second air pipe bracket 504 sprays inert gas, causing the rising cavitation bubble flow to rotate in an annular manner along the side wall of the stirring acceleration zone 203b, as shown. Figure 7 As shown, this can be achieved by angling the jet nozzle opening angle rather than perpendicular to the sidewall of the gas pipe 501. During the two aforementioned processes, cavitation bubbles and nitrogen bubbles undergo intense shear, collision, and fusion, achieving microscopic mixing and diffusion of dual-mode bubbles and liquid water. The mixed fluid continues to rise, exiting the quartz glass tunnel 2 and entering the static pressure recovery section 110 described below to eliminate turbulence, forming a uniform, stable vertical laminar flow containing dual-mode bubbles before continuing to flow upward toward the wafer positioning mechanism 6.

[0046] The wafer positioning mechanism 6 is disposed above the pressing portion 106 , and the area between the wafer positioning mechanism 6 and the pressing portion 106 is the static pressure recovery section 110 .

[0047] The wafer positioning mechanism 6 includes two wafer supports 601 positioned opposite each other. The wafer supports 601 are provided with multiple vertically spaced slots for wafers 0. A wafer stopper 602 is positioned above the wafer supports 601. The slots support the lower portion of wafer 0, while the stopper 602 holds the upper portion of wafer 0 in place, preventing significant lateral shifting during the cleaning process.

[0048] The mixed fluid flows from the wafer positioning mechanism 6 and the bottom of wafer 0 to wafer 0, and flows through the gap between adjacent wafers 0. Due to the existence of the wafer positioning mechanism 6 and wafer 0, the flow area of ​​the mixed fluid is reduced, so that the mixed fluid is accelerated and forms a laminar flow vertically through the front and back surfaces of wafer 0.

[0049] Furthermore, flow limiting structures 603 are provided on both sides of the wafer support frame 601 to further reduce the flow area of ​​the mixed fluid.

[0050] A through-flow guide tunnel 604 is provided below the receiving grooves on both sides of the wafer positioning mechanism 6 for allowing the mixed fluid to flow in and clean the edge of the wafer 0 .

[0051] In this embodiment, a wafer in-position sensor 111 and a wafer positioning failure sensor 112 are also provided on the trough body 101, as well as a sensor waterproof cover 113 covering the periphery of the wafer in-position sensor 111 and the wafer positioning failure sensor 112. The wafer in-position sensor 111 confirms that there is a wafer on the wafer support frame 601, and the wafer on the wafer support frame 601 does not fall into the positioning groove of the wafer support frame 601. The wafer protrusion is sensed by the wafer positioning failure sensor 112, and the wafer positioning failure is confirmed.

[0052] As a preferred solution of this embodiment, the medium-temperature fluid supply system 3 is further provided with an overflow valve 302 for micro-flow water replenishment, an air-controlled valve 303 for rapid water replenishment, and a solenoid valve 304 for controlling the opening and closing of the air-controlled valve 303. When cleaning is started and ended, the air-controlled valve 303 is opened for rapid water replenishment and draining. During the cleaning process, the air-controlled valve 303 is closed and the overflow valve 302 is opened for continuous micro-flow water replenishment, maintaining a continuous overflow in the tank 101, discharging contaminants in the floating liquid water, and keeping the tank 101 clean. After cleaning is completed, the cavitation bubble generating assembly 4 and the inert gas source are turned off. The rapid draining of water after the air-controlled valve 303 is opened can also quickly flush the wafer 0, eliminating air film retention on the surface of the wafer 0.

[0053] A first quick exhaust valve 109 connected to the water collection tank 104 is provided at the bottom of the overflow tank 1. At least two first quick exhaust valves 109 are arranged on both sides of the bottom of the overflow tank 1 along the extension direction of the wafer 0 plane, and are used to discharge the liquid in the tank body 101 after the rapid flushing is completed. The symmetrical arrangement can ensure the realization of equal flow rate quick discharge and uniform and rapid flushing of the wafer 0 surface.

[0054] A second quick-discharge valve 205 is provided at the bottom of the quartz glass tunnel 2 for draining and flushing the remaining liquid in the quartz glass tunnel 2 and flushing the interior of the quartz glass tunnel 2 with a high-speed discharged water flow.

[0055] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only used to facilitate the description of the present invention, and do not imply or require that the device or element referred to must have a specific orientation or construction method, and therefore should not be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the objects of description and should not be understood as limiting the importance or order, and the features defined by such terms may explicitly or implicitly include one or more such features. Unless otherwise specified, "multiple" in the description of the present invention refers to two or more.

[0056] The terms "installed," "connected," and "connected," unless otherwise expressly defined, should be understood broadly, including but not limited to fixed, removable, or integrally molded connections; mechanical or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand their meaning based on the specific technical solutions. The fixed connections referred to in the present invention, unless otherwise stated, include both removable fixed connections (such as bolts and screws) and non-removable fixed connections (such as rivets and welding), and may also include integral structures achieved through an integral molding process (such as casting) (except where integral molding is clearly not possible).

[0057] Unless otherwise stated, the terms used in any technical solution disclosed in the present invention to express positional relationships or shapes all cover states or shapes that are approximate, similar or close thereto.

[0058] Any component provided by the present invention may be assembled from multiple separate components, or may be a separate component manufactured by an integral molding process.

[0059] It should be noted that the structures, proportions, sizes, etc. depicted in the drawings of this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them. They are not used to limit the conditions under which the present invention can be implemented. Therefore, they have no substantive technical significance. Any modification of the structure, change in the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed in the present invention without affecting the efficacy and purpose that can be achieved by the present invention.

[0060] In the embodiments of the present application, the same reference numerals are used to represent the same component or the same part.

[0061] Adaptive changes based on actual needs are all within the scope of protection of the present invention.

[0062] It should be noted that it will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims, not the foregoing description, and it is intended that all variations within the meaning and range of equivalents of the claims be encompassed within the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0063] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A wafer cleaning method, characterized in that: The following steps are involved: S1 generates a continuous overflow of medium-temperature liquid water in the cleaning fluid flow channel; S2 generates a controllable cavitation bubble flow in the liquid water; S3 introduces an auxiliary bubble flow and stirs and mixes the cavitation bubble flow to form a mixed fluid containing dual-mode bubbles; S4. converting the mixed fluid into a vertical laminar flow directed toward the surface of the wafer (0); S5. Using dual-mode bubble collapse to generate ultrasonic waves of different frequencies to grade and clean the surface contaminants of the wafer (0); S6. Continuous discharge of pollutants through overflow.

2. The wafer cleaning method according to claim 1, wherein: The step S2 comprises: S201. Using a focused laser beam to irradiate liquid water; S202. Scan the laser focus in three dimensions using a galvanometer system to edit the cavitation bubble array flow within a preset three-dimensional space.

3. The wafer cleaning method according to claim 2, wherein: The step S3 comprises: S301. Cavitation bubbles converge to the upper part of the liquid water flow by buoyancy; S302. Inert gas jets are injected tangentially to the convergence zone to drive stirring; S303 accelerates the diffusion of cavitation bubbles, inert gas bubbles and liquid water by annular stirring; S304. Static pressure is restored to form a uniform vertical laminar flow containing bubbles.

4. The wafer cleaning method according to claim 3, wherein: The auxiliary bubble flow is an inert gas jet.

5. The wafer cleaning method according to claim 4, wherein: In the step S5: Assist bubble collapse to remove micron-sized particles; The collapse of cavitation bubbles removes nano-sized particles.

6. A wafer cleaning device for implementing the cleaning method according to any one of claims 1 to 5, characterized in that: include: An overflow trough (1) for receiving and guiding cleaning fluid; a quartz glass tunnel (2), in fluid communication with the overflow trough (1), for forming a cleaning fluid flow channel; a medium-temperature fluid supply system (3) for providing temperature-controlled liquid water to the quartz glass tunnel (2); a cavitation bubble generating assembly (4) for controllably generating cavitation bubbles in the liquid water within the quartz glass tunnel (2); A stirring and mixing component (5) is used for injecting an auxiliary bubble flow and stirring and mixing to form a mixed fluid; A wafer positioning mechanism (6) is provided in the overflow trough (1) and is located downstream of the stirring and mixing assembly (5), and is used to vertically fix the wafer (0) to be cleaned. The wafer positioning mechanism (6) cooperates with the quartz glass tunnel (2) to form a vertical laminar flow guide structure; Wherein, the vertical laminar flow guiding structure is configured to enable the mixed fluid to form a vertical laminar flow and flow over the surface of the wafer (0).

7. The wafer cleaning device according to claim 6, characterized in that: The quartz glass tunnel (2) comprises: a horizontal section (201), wherein the cavitation bubble generating assembly (4) generates cavitation bubbles in the horizontal section (201); A turning section (202) is used to turn the horizontal flow of fluid into a vertical flow; A vertical section (203), wherein the cross-sectional area of ​​the vertical section (203) gradually increases from bottom to top, and is sequentially divided into a stirring start zone (203a) and a stirring acceleration zone (203b) from bottom to top.

8. The wafer cleaning device according to claim 7, characterized in that: The stirring and mixing assembly (5) comprises: An air pipe (501) is used to communicate with an inert gas source and extends to the interior of the quartz glass tunnel (2), with the end of the air pipe being sealed; The jet nozzles are arranged in a directionally open manner on the side wall of the air pipe (501). The jet nozzles in the stirring starting area (203a) are used to make the cavitation bubble flow diffuse laterally, and the jet nozzles in the stirring acceleration area (203b) are used to make the cavitation bubble flow rotate annularly and accelerated along the side wall of the stirring acceleration area (203b).

9. The wafer cleaning device according to claim 6, wherein: The cavitation bubble generating component (4) comprises: A laser generator (401) for emitting a laser beam with a wavelength of 1047 nm or 1064 nm; The galvanometer system controls the laser focus to perform three-dimensional scanning in the liquid water in the quartz glass tunnel (2) to form cavitation bubbles.

10. The wafer cleaning device according to claim 6, wherein: The overflow trough (1) comprises: A trough body (101) is used to accommodate a wafer positioning mechanism (6); an overflow channel (102) is provided at the top of the trough body (101); the overflow channel (102) is connected to a drain pipe (103); a water collecting trough (104) is provided on the periphery of the trough body (101); the drain pipe (103) extends into the water collecting trough (104); The bottom of the trough body (101) is provided with a through hole for allowing the quartz glass tunnel (2) to pass through, a supporting portion (105) for supporting the end flange (204) of the quartz glass tunnel (2), and a pressing portion (106) for pressing the end flange (204), the pressing portion (106) being in contact with both the end flange (204) and the supporting portion (105), a first sealing member being provided in the area where the pressing portion (106) contacts the end flange (204), and a second sealing member being provided in the area where the pressing portion (106) contacts the supporting portion (105); A first quick exhaust valve (109) communicating with the water collecting tank (104) is provided at the bottom of the overflow tank (1), and at least two of the first quick exhaust valves (109) are arranged on both sides of the bottom of the overflow tank (1) along the extension direction of the wafer (0) plane; A second quick exhaust valve (205) is provided at the bottom of the quartz glass tunnel (2).

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