Wafer cleaning apparatus and cleaning method

Abstract

The application discloses a wafer cleaning device and a cleaning method, and relates to the technical field of semiconductor manufacturing. The cleaning device comprises the following steps: S1. generating a 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 double-mode bubbles; S4. converting the mixed fluid into a vertical laminar flow and guiding the wafer surface; S5. using different frequency ultrasonic waves generated by the collapse of the double-mode bubbles to perform fractional cleaning on the wafer surface contaminants; and S6. continuously discharging the contaminants through the overflow. According to the application, the cavitation bubble flow and the auxiliary bubble flow are generated in the cleaning fluid flow channel, the double-mode bubble flow is formed through stirring and mixing, the high-frequency ultrasonic waves and the low-frequency ultrasonic waves are synchronously released by the collapse of the double-mode bubbles to remove the nanoparticles and the microparticles, one step replaces the traditional multi-step cleaning, the risk of wafer transfer damage is eliminated, and the cleaning period is greatly shortened.

Description

TECHNICAL FIELD

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

[0002] In the field of semiconductor wafer manufacturing, surface cleaning after chemical mechanical polishing (CMP) is a key link affecting yield. The existing technology faces three contradictions that are difficult to reconcile:

[0003] 1. Conflict between cleaning efficiency and effect:

[0004] To remove micron-level polishing residues, low-frequency high-power ultrasonic waves are needed, but strong cavitation effect can easily cause micro-damage to the wafer surface;

[0005] For nanoscale particles, high-frequency weak ultrasonic waves are needed, but when the energy is insufficient, chemical additives are needed, which introduces the risk of secondary pollution.

[0006] The multi-step switching significantly prolongs the process time, and the frequent wafer transfer increases the probability of scratches.

[0007] 2. Pollution source control dilemma:

[0008] Metal ultrasonic transducers (such as titanium alloy) release Fe + / Ni + ions during cavitation, polluting high-purity silicon substrates;

[0009] Non-metal piezoelectric ceramic transducers are fragile and expensive, making it difficult to meet mass production needs.

[0010] 3. Temperature sensitivity and energy efficiency contradiction:

[0011] Low-temperature (<40℃) cleaning fluid can inhibit chemical reactions, but significantly weakens cavitation intensity, reducing the removal rate of nanoscale particles;

[0012] Although heating to >60℃ improves cavitation activity, it accelerates the cross-linking and solidification of polishing liquid residues, making it more difficult to remove.

[0013] Therefore, in a single physical cleaning process, it is still a technical problem to simultaneously achieve efficient removal of micron / nanoscale particles, no metal pollution, and zero damage to the wafer. SUMMARY

[0014] The purpose of the present application is to provide a wafer cleaning device and a cleaning method to solve the above-mentioned problems existing in the prior art, and to simultaneously achieve efficient removal of micron / nanoscale particles, no metal pollution, and zero damage to the wafer in a single physical cleaning process.

[0015] To achieve the above object, the present application provides the following solutions.

[0016] A wafer cleaning method, characterized in that it comprises the following steps:

[0017] S1. Generating a continuous overflow of intermediate-temperature liquid water in a cleaning fluid flow channel;

[0018] S2. Generating a controllable cavitation bubble flow in the liquid water;

[0019] S3. Introducing an auxiliary bubble flow and stirring the cavitation bubble flow to form a mixed fluid containing double-mode bubbles;

[0020] S4. Converting the mixed fluid into a vertical laminar flow directed to the wafer surface;

[0021] S5. Using different frequency ultrasonic waves generated by the collapse of double-mode bubbles to fractionally clean the wafer surface contaminants;

[0022] S6. Continuously discharging the contaminants through the overflow.

[0023] In an exemplary embodiment, the step S2 comprises:

[0024] S201. Focusing a laser beam to irradiate the liquid water;

[0025] S202. Editing a cavitation bubble array flow in a preset three-dimensional space by stereoscopic scanning of the laser focal point through a galvanometer system.

[0026] In an exemplary embodiment, the step S3 comprises:

[0027] S301. Cavitation bubbles converge to the upper part of the liquid water flow using buoyancy;

[0028] S302. Driving stirring by injecting inert gas jets to both sides of the convergence area tangentially;

[0029] S303. Accelerating the mixing and diffusion of cavitation bubbles, inert gas bubbles, and liquid water through annular stirring;

[0030] S304. Restoring static pressure to form a uniform bubble-containing vertical laminar flow.

[0031] In an exemplary embodiment, the auxiliary bubble flow is an inert gas jet.

[0032] In an exemplary embodiment, in the step S5:

[0033] The auxiliary bubble collapse removes micrometer-sized particulate matter;

[0034] The cavitation bubble collapse removes nanometer-sized particulate matter.

[0035] The application also provides a wafer cleaning device for implementing the above cleaning method, characterized by comprising:

[0036] An overflow tank for containing and guiding the cleaning fluid;

[0037] A quartz glass tunnel in fluid communication with the overflow tank for forming a cleaning fluid flow channel;

[0038] A medium-temperature fluid supply system for providing temperature-controlled liquid water to the quartz glass tunnel;

[0039] A cavitation bubble generating assembly for controllably generating cavitation bubbles in the liquid water in the quartz glass tunnel;

[0040] A stirring and mixing assembly for injecting an auxiliary bubble flow and stirring and mixing to form a mixed fluid;

[0041] A wafer positioning mechanism arranged in the overflow tank downstream of the stirring and mixing assembly for vertically fixing a wafer to be cleaned, the wafer positioning mechanism cooperating with the quartz glass tunnel to form a vertical laminar flow guide structure;

[0042] Wherein, the vertical laminar flow guide structure is configured to make the mixed fluid form a vertical laminar flow through the surface of the wafer.

[0043] In an exemplary embodiment, the quartz glass tunnel comprises:

[0044] A horizontal section in which the cavitation bubble generating assembly generates cavitation bubbles;

[0045] A turning section for turning the fluid flowing horizontally to vertically;

[0046] A vertical section, the cross-sectional area of which gradually increases from bottom to top, and the vertical section is sequentially divided into a stirring start zone and a stirring acceleration zone from bottom to top.

[0047] In an exemplary embodiment, the cavitation bubble generating assembly comprises:

[0048] A laser generator for emitting a laser beam with a wavelength of 1047 nm or 1064 nm;

[0049] A galvanometer system for controlling the laser focal point to stereoscopically scan in the liquid water in the quartz glass tunnel to form cavitation bubbles.

[0050] In an exemplary embodiment, the stirring and mixing assembly comprises:

[0051] A gas tube for communicating with an inert gas source and extending to the inside of the quartz glass tunnel, the end of the gas tube being closed;

[0052] The jet flow orifices are arranged on the side wall of the trachea and are used to diffuse the cavitation bubble flow transversely in the stirring starting area and to accelerate the rotation of the cavitation bubble flow along the side wall of the stirring acceleration area.

[0053] In an exemplary embodiment, the overflow tank comprises:

[0054] The tank body is provided with an overflow channel at the top, and a drain pipe is communicated with the overflow channel; a water collecting tank is arranged on the outer periphery of the tank body, and the drain pipe extends into the water collecting tank;

[0055] The bottom of the tank body is provided with a through hole for 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 is in contact with the end flange and the supporting portion at the same time, the area where the pressing portion is in contact with the end flange is provided with a first sealing element, and the area where the pressing portion is in contact with the supporting portion is provided with a second sealing element;

[0056] The bottom of the overflow tank is provided with a first quick drain valve communicated with the water collecting tank, and at least two first quick drain valves are arranged on both sides of the bottom of the overflow tank along the extension direction of the wafer plane;

[0057] The bottom of the quartz glass tunnel is provided with a second quick drain valve.

[0058] The present application has the following technical effects compared with the prior art:

[0059] 1. By generating cavitation bubble flow (high frequency source) and auxiliary bubble flow (low frequency source) in the cleaning fluid flow channel, a double-mode bubble fluid is formed by stirring and mixing, and high-frequency ultrasonic waves (>1MHz) are released synchronously by the collapse of the double-mode bubbles to remove nanoparticles, and low-frequency ultrasonic waves (<100kHz) are released to remove microparticles, which replaces the traditional multi-step cleaning, eliminates the risk of wafer transfer damage, and greatly shortens the cleaning period.

[0060] 2. The energy generated by the collapse of the cavitation bubbles is transmitted to the wafer surface through the fluid medium, replacing the ultrasonic waves generated by the traditional metal ultrasonic transducer, and completely eliminating Fe + / Ni + ion contamination.

[0061] 3. The vertical laminar flow ensures that the double-mode bubbles uniformly cover the wafer surface, the collapse energy precisely acts on the contaminant interface, the wafer damage rate is extremely low, the overflow sewage is brought out of the contaminant in real time, and a "high-efficiency cleaning-zero contamination-zero damage" technical closed loop is formed. BRIEF DESCRIPTION OF DRAWINGS

[0062] 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.

[0063] Figure 1 A schematic structural diagram of a wafer cleaning device disclosed in a specific embodiment of the present invention;

[0064] Figure 2 for Figure 1 A side sectional view of

[0065] Figure 3 for Figure 1 A front sectional view of

[0066] Figure 4 for Figure 1 Schematic diagram of the structure of the quartz glass tunnel;

[0067] Figure 5 for Figure 2 Schematic diagram of the structure of the stirring and mixing component;

[0068] Figure 6 Schematic diagram of the lateral diffusion of cavitation bubble flow in the stirring starting area;

[0069] Figure 7 Schematic diagram of the accelerated rotation of cavitation bubble flow in the stirring acceleration zone;

[0070] in:

[0071] 0. Wafer;

[0072] 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;

[0073] 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;

[0074] 3. Medium-temperature fluid supply system; 301. Static pressure water supply pipe; 302. Overflow valve; 303. Air control valve; 304. Solenoid valve;

[0075] 4. Cavitation bubble generation component; 401. Laser generator; 402. Laser scanning optical path;

[0076] 5. Stirring mixing assembly; 501. Gas pipe; 503. First gas pipe support; 504. Second gas pipe support; 505. Third gas pipe support;

[0077] 6. Wafer positioning mechanism; 601. Wafer support frame; 602. Wafer limiting block; 603. Flow limiting structure; 604. Flow guiding tunnel. DETAILED DESCRIPTION

[0078] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the present specification. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0079] The purpose of the present application is to provide a wafer cleaning device and a cleaning method to solve the problems existing in the prior art, to achieve efficient removal of micron / nanometer particles, no metal pollution, temperature self-adaptive control, and zero damage to the wafer in a single physical cleaning process.

[0080] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0081] Embodiment one

[0082] The present embodiment provides a wafer cleaning method, comprising the following steps:

[0083] S1. Generating continuous overflow of medium-temperature liquid water in the cleaning fluid flow channel;

[0084] Wherein, the temperature range of the medium-temperature clean liquid water is 50-70℃:

[0085] When the water temperature is higher than 50℃, the thermal motion of water molecules is significantly intensified, which reduces the surface tension and viscous resistance of liquid water, so that the subsequent generated cavitation bubbles are more easily collapsed and release high-intensity shock waves;

[0086] Setting the upper limit of the temperature to 70℃ can effectively avoid the solidification or sintering of the polishing residues on the surface of the wafer 0 due to high temperature, and ensure that the pollutants exist in a loose state for subsequent removal;

[0087] The continuous overflow state is maintained by a static pressure water supply system, forming a stable vertical laminar flow, which provides the fluid dynamics basis for the subsequent bubble mixing and collapse.

[0088] S2. Generating a controllable cavitation bubble flow in the liquid water;

[0089] Specifically comprising:

[0090] S201. Adopting laser beam focusing irradiation of medium temperature liquid water, using laser energy to induce local liquid water molecule vaporization at the focal point, generating cavitation bubbles with a cross-sectional area of 0.1-10 μm, replacing the traditional metal ultrasonic vibration plate, avoiding ion pollution;

[0091] S202. Editing cavitation bubble array flow in the preset three-dimensional space by three-dimensional scanning of the laser focal point through the galvanometer system. The galvanometer system performs three-dimensional scanning on the laser focal point, accurately edits the distribution density, size and motion trajectory of the cavitation bubbles in the preset space coordinates, and forms a cavitation bubble array flow with a specific spatial configuration. This technology breaks through the physical limitations of traditional ultrasonic vibration plates and realizes programmed control of cavitation position and intensity.

[0092] S3. Introducing auxiliary bubble flow and stirring the cavitation bubble flow to form a mixed fluid containing double-mode bubbles;

[0093] Specifically comprising:

[0094] S301. Cavitation bubbles converge to the upper part of the liquid water flow using buoyancy;

[0095] S302. Driving stirring by injecting inert gas jets tangentially to both sides of the convergence zone;

[0096] S303. Accelerating the mixing and diffusion of cavitation bubbles, inert gas bubbles and liquid water through annular stirring;

[0097] S304. Forming a uniform bubble-containing vertical laminar flow by restoring static pressure.

[0098] Wherein, the auxiliary bubble flow is an inert gas jet, preferably nitrogen.

[0099] Wherein, based on the physical property that the density of cavitation bubbles is lower than that of liquid water, cavitation bubbles converge to the upper layer of the flow under the action of buoyancy. When the fluid is diverted to the vertical direction, the converged cavitation bubble flow enters the stirring zone, and inert gas such as nitrogen is injected tangentially on both sides of the converged cavitation bubbles. The high-speed jet of inert gas simultaneously introduces an auxiliary bubble flow and drives the rotation and upward movement of the cavitation bubble group. During the rotation and upward movement, cavitation bubbles and inert gas bubbles undergo strong shearing, collision and fusion, realizing microscale mixing and diffusion of double-mode bubbles and liquid water. After mixing, the fluid passes through the static pressure recovery section 110 to eliminate turbulence, forming a uniform and stable vertical laminar flow containing double-mode bubbles, providing a carrier for staged cleaning.

[0100] S4. Converting the mixed fluid into a vertical laminar flow and directing it to the surface of the wafer 0;

[0101] Wherein, multiple wafers 0 are vertically arranged above the static pressure recovery section 110, and a gap is left between the wafers 0, so that the mixed fluid accelerates and forms a laminar flow state vertically through the front and back surfaces of the wafers 0. This laminar flow has high directionality and low shear stress characteristics, ensuring uniform distribution of bubbles close to the wafer 0 surface movement, while avoiding high flow rate damage to the wafer 0 microstructure. Utilizing the synergistic effect of gravity and fluid dynamics, the bubble collapse energy is concentrated on the pollutant adhesion interface.

[0102] S5. Utilize different frequency ultrasonic waves generated by dual-mode bubble collapse to fractionally clean the wafer 0 surface pollutants;

[0103] Wherein, auxiliary bubble collapse removes micrometer-sized particulate matter; cavitation bubble collapse removes nanometer-sized particulate matter.

[0104] When the dual-mode bubbles in the mixed laminar flow contact the wafer 0 surface, they collapse, and the physical mechanism has a fractional cleaning effect: auxiliary bubble collapse generates low-frequency high-intensity shock waves (usually <100 kHz), forming micrometer-sized micro-jets and shear forces, effectively peeling off micrometer-sized polishing particles with strong adhesion; while laser cavitation bubble collapse excites high-frequency stress waves (usually >1 MHz), through the high-frequency oscillation of cavitation micro-jets and the local high-temperature and high-pressure effect (up to 5000K, 1000atm), desorbing nanometer-sized molecular pollutants and destroying their surface binding energy. The two collapse modes are complementary in time and space scales, achieving the synergistic removal of pollutants of all sizes.

[0105] S6. Continuously discharge pollutants through overflow;

[0106] During the cleaning process, pollutants are continuously discharged by overflow along with the vertical laminar flow, and the overflow tank ensures that the fluid renewal rate matches the pollution load. This dynamic pollution discharge mechanism prevents the secondary deposition of peeled-off pollutants while maintaining the cleanliness of the cleaning zone fluid.

[0107] Example Two

[0108] The embodiment provides a wafer cleaning device for realizing the cleaning method in the first embodiment, which 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 is used as a main space for cleaning the wafer 0 and is used for containing and guiding the cleaning fluid, the quartz glass tunnel 2 is in fluid communication with the overflow tank 1 and is used for forming a cleaning fluid flow channel, the medium-temperature fluid supply system 3 is used for providing temperature-controlled liquid water to the quartz glass tunnel 2, the cavitation bubble generating assembly 4 is used for controllably generating cavitation bubbles in the liquid water in the quartz glass tunnel 2, the stirring and mixing assembly 5 is used for injecting auxiliary bubble flow and stirring and mixing to form mixed fluid, and the wafer positioning mechanism 6 is arranged in the overflow tank 1 and is located downstream of the stirring and mixing assembly 5 and is used for vertically fixing 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, so that the mixed fluid forms a vertical laminar flow and flows through the surface of the wafer 0, and the surface of the wafer 0 is cleaned in stages.

[0109] Specifically, the overflow tank 1 comprises a tank body 101 for containing the wafer 0 and the wafer positioning mechanism 6, the tank body 101 is provided with an overflow channel 102 at the top, and the overflow channel 102 is communicated with a drain pipe 103. A water collecting tank 104 is arranged on the outer periphery of the tank body 101, and the drain pipe 103 extends into the water collecting tank 104. During the cleaning process, the pollutants continuously overflow with the vertical laminar flow and are discharged into the water collecting tank 104 through the overflow channel 102 and the drain pipe 103.

[0110] The tank body 101 is provided with a through hole for the quartz glass tunnel 2 to pass through, a supporting portion 105 for supporting an end flange 204 of the quartz glass tunnel 2, and a pressing portion 106 for pressing the end flange 204. The pressing portion 106 is in contact with the end flange 204 and the supporting portion 105 at the same time, a first sealing element is arranged at the region where the pressing portion 106 is in contact with the end flange 204, and a second sealing element is arranged at the region where the pressing portion 106 is in contact with the supporting portion 105.

[0111] The quartz glass tunnel 2 comprises a horizontal section 201, a turning section 202 and a vertical section 203. The cavitation bubble generating assembly 4 generates cavitation bubbles in the horizontal section 201, the turning section 202 is used for turning the horizontal flow of fluid into vertical flow, and the cross-sectional area of the vertical section 203 gradually increases from bottom to top, and the vertical section 203 comprises a stirring starting area 203a and a stirring accelerating area 203b from bottom to top.

[0112] The medium-temperature fluid supply system 3 comprises a temperature sensor and a heater, which are used for adjusting the water temperature, so that the temperature of the liquid water is precisely controlled at 50-70 DEG C, and the temperature-controlled liquid water is provided to the quartz glass tunnel 2 through a static pressure water supply pipe 301.

[0113] The cavitation bubble generating assembly 4 comprises a laser generator 401 and a galvanometer system integrated in the laser generator 401, and the laser generator 401 extends to the inside of the quartz glass tunnel 2 through a laser scanning light path 402. The laser generator 401 is used to emit a laser beam with a wavelength of 1047 nm or 1064 nm, and the galvanometer system is used to control the laser focal point to stereoscopically scan in the liquid water in the quartz glass tunnel 2 to form cavitation bubbles.

[0114] The laser generator 401 emits near-infrared light, and the wavelength is selected in the near-infrared secondary absorption peak band of liquid water (the main peak is at 3000 nm), which is offset from the optical absorption peak of the quartz glass tunnel 2. The light transmittance of the quartz glass in this band is greater than 99% (absorption rate is less than 0.1%), which ensures that the energy is efficiently coupled to the liquid water rather than being absorbed by the tunnel material, avoiding the risk of thermal damage.

[0115] The computer controls the galvanometer system to edit a three-dimensional bubble array such as a grid, a spiral, etc. in the water flow.

[0116] The stirring and mixing assembly 5 comprises an air pipe 501 and jet holes. The air pipe 501 is used to communicate with an inert gas source and extends to the inside of the quartz glass tunnel 2, and the end of the air pipe 501 is closed. The jet holes are arranged in the side wall of the air pipe 501. The jet holes in the stirring start area 203a are used to diffuse the cavitation bubble flow to the entire stirring start area 203a, and the jet holes in the stirring acceleration area 203b are used to make the cavitation bubble flow rotate along the side wall of the stirring acceleration area 203b in a ring shape.

[0117] Specifically, the air pipe 501 is introduced from the side wall of the bottom of the tank body 101, a first air pipe support 503 is arranged at the outlet of the quartz glass tunnel 2, a second air pipe support 504 is arranged at the junction of the stirring start area 203a and the stirring acceleration area 203b of the vertical section 203, and a third air pipe support 505 is arranged at the beginning of the stirring start area 203a. After the air pipe 501 is introduced from the side wall of the bottom of the tank body 101, it extends to the inside of the quartz glass tunnel 2 from the outlet of the quartz glass tunnel 2 and is arranged on the first air pipe support 503, the second air pipe support 504 and the third air pipe support 505 in sequence.

[0118] 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, as shown by the arrows in the middle of the figure. Figure 2 When the fluid is turned to the vertical direction by the turning section 202 of the quartz glass tunnel 2 and enters the vertical section 203, the gathered cavitation bubble flow first enters the 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.

[0119] 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 .

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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 .

[0124] In this embodiment, the groove body 101 is further provided with a wafer in position sensor 111 and a wafer positioning failure sensor 112, and a sensor waterproof cover 113 is arranged on 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. If the wafer protrudes and is sensed by the wafer positioning failure sensor 112, it is confirmed that the wafer positioning fails.

[0125] As a preferred scheme of this embodiment, the medium-temperature fluid supply system 3 is further provided with an overflow valve 302 for micro-flow water supply and a gas control valve 303 for rapid water supply, and an electromagnetic valve 304 for controlling the opening and closing of the gas control valve 303. When the cleaning is started and ended, the gas control valve 303 is opened, and rapid water supply and drainage are performed; during the cleaning process, the gas control valve 303 is closed, and the overflow valve 302 is opened, for continuous micro-flow water supply, to maintain continuous overflow in the groove body 101, to discharge the pollutants in the floating liquid water, and to keep the groove body 101 clean. After the cleaning is completed, the cavitation bubble generating assembly 4 and the inert gas source are closed, and the rapid water drainage after the gas control valve 303 is opened can also rapidly flush the wafer 0, to eliminate the gas film retention on the surface of the wafer 0.

[0126] The bottom of the overflow groove 1 is provided with a first rapid drainage valve 109 connected to the water collecting groove 104. At least two first rapid drainage valves 109 are arranged on both sides of the bottom of the overflow groove 1 along the extension direction of the wafer 0 plane, to drain the liquid in the groove body 101 after the rapid flushing is completed. The symmetrical arrangement can ensure that the equal flow rate rapid drainage is achieved, to uniformly and rapidly flush the surface of the wafer 0.

[0127] The bottom of the quartz glass tunnel 2 is provided with a second rapid drainage valve 205, to drain the remaining liquid in the quartz glass tunnel 2, and to flush the inside of the quartz glass tunnel 2 by using the high-speed water flow.

[0128] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are all based on the orientations or positional relationships shown in the drawings, and are only used for the convenience of describing the present application, and do not imply or require that the devices or elements referred to must have a particular orientation or configuration, and therefore should not be understood as limiting the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description objects, and should not be understood as limiting the importance or order, and such terms limited features can be explicitly or implicitly include one or more features. Unless otherwise stated, "multiple" in the description of the present application means two or more.

[0129] For the terms "mounting", "connecting", "connection", unless otherwise explicitly defined, should be understood in a broad sense, including but not limited to fixed connection, detachable connection or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through intermediate medium; and internal communication of two elements. Those skilled in the art can understand its meaning according to the specific technical solutions. In the present application, the fixed connection involved, unless otherwise stated, includes detachable fixed connection (such as bolt, screw connection), and also includes non-detachable fixed connection (such as riveting, welding), and also includes the integral structure realized by integral molding process (except for obvious integral molding).

[0130] The terms used to represent the positional relationship or shape in any technical solution disclosed in the present application, unless otherwise stated, cover the approximate, similar or close state or shape.

[0131] Any component provided in the present application can be assembled from a plurality of individual components, or can be a single component manufactured by integral molding process.

[0132] It should be understood that the structure, proportion, size and the like shown in the drawings of the present application are only used to cooperate with the content disclosed in the specification, so as to be understood and read by those skilled in the art, and do not have technical substantive significance, and any modification of structure, change of proportion relationship or adjustment of size, without affecting the effect and purpose that can be achieved by the present application, should still fall within the scope covered by the disclosed technical content of the present application.

[0133] In the embodiments of the present application, the same reference signs represent the same component or the same part.

[0134] Any adaptive change according to actual needs is within the protection scope of the present application.

[0135] It should be noted that for those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be realized in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0136] The principles and implementation manners of the present application are described by using specific examples in the present application, and the above examples are only used for helping to understand the method of the present application and its core idea; meanwhile, for the general technical personnel in the art, according to the idea of the present application, the specific implementation manners and application ranges will be changed. In conclusion, the content of the present specification should not be understood as the limitation of the present application.

Claims

1. A wafer cleaning method, characterized in that: The following steps are involved: S1. Generating a continuous overflow of medium-temperature liquid water in the cleaning fluid flow channel, wherein the temperature of the medium-temperature liquid water ranges from 50°C to 70°C; S2. Generating a controllable cavitation bubble flow in the liquid water; specifically comprising: S201. Using a focused laser beam to irradiate liquid water, the laser energy triggers local vaporization of liquid water molecules at the focal point, generating cavitation bubbles with a cross-sectional area of ​​0.1-10 μm. S202. The laser focus is scanned stereoscopically by the galvanometer system to edit the cavitation bubble array flow in a preset three-dimensional space; S3. Introducing an auxiliary bubble flow and stirring and mixing the cavitation bubble flow, wherein the auxiliary bubble flow is an inert gas jet to form a mixed fluid containing dual-mode bubbles; specifically comprising: 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 recovery to form a uniform vertical laminar flow containing 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: In the step S5: Assist bubble collapse to remove micron-sized particles; The collapse of cavitation bubbles removes nano-sized particles.

3. A wafer cleaning device for implementing the cleaning method according to claim 1 or 2, 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; 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).

4. The wafer cleaning device according to claim 3, 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.

5. The wafer cleaning device according to claim 4, 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).

6. The wafer cleaning device according to claim 3, characterized in that: 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.

7. The wafer cleaning device according to claim 3, characterized in that: 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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