Wafer surface cleaning device

Abstract

The application discloses a wafer surface cleaning device, which comprises a cleaning tank, wherein a wafer carrier is inserted into the cleaning tank along the up-down direction, and the cleaning device further comprises an overflow mechanism and a surface-to-be-cleaned processing mechanism arranged in sequence from bottom to top and moving synchronously. According to the application, the overflow mode is adopted, and the accurate control of the descending speed of the cleaning liquid surface is realized by cooperating with the resistance formed by the liquid film on the surface, so that the cleaning liquid surface can be kept stable. On the other hand, the synchronous downward movement of the overflow mechanism and the surface-to-be-cleaned processing mechanism is realized, the height of the airflow relative to the cleaning liquid surface is kept unchanged, the cleaning liquid is overflowed and discharged, the first and second airflows are blown and cooperated to keep the cleaning liquid surface at the junction perpendicular to the surface-to-be-cleaned of the wafer and form a liquid film which is not affected by the liquid level fluctuation, the trend of the cleaning liquid climbing along the wafer surface is effectively inhibited, the probability of the cleaning liquid widely remaining on the wafer surface is reduced, and the traceless drying of the wafer surface is gradually realized from top to bottom.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of semiconductor processing, and particularly relates to a wafer surface cleaning device. BACKGROUND

[0002] In the semiconductor industry, after a wafer wet process, the wafer process surface residual chemical agent usually needs to be cleaned and dried to ensure that the wafer process surface chemical agent is cleaned and the number of particles after drying meets the requirements of subsequent processes.

[0003] Currently, the traditional cleaning process includes: (1) soaking; and (2) drying, wherein the wafer is loaded on a carrier, and the carrier is immersed in a cleaning tank containing cleaning liquid to complete the soaking; and the drying means mainly includes high-purity nitrogen drying and Malan Goni drying.

[0004] However, in the above drying process, the following technical defects may exist:

[0005] 1. The high-purity nitrogen drying is mainly based on the unloading of the soaking liquid, and the exposed wafer is dried by blowing high-purity nitrogen. Although it seems simple and efficient, when the gas acts on the wafer surface with large water droplets, the water droplets will splash, causing the already dried position to introduce water droplets again, and after being dried again, water marks will be formed. The water marks are very difficult to clean, and if not cleaned deeply, the wafer will be scrapped.

[0006] 2. In the drying method based on the Malan Goni principle, when two liquids with different surface tensions contact, the surface liquid film (also known as IPA liquid film or isopropyl alcohol liquid film) keeps flowing from the area with low surface tension to the area with high surface tension. At the same time, the cleaning liquid is discharged from the bottom of the cleaning tank under the action of gravity. As the liquid level drops, the water flow converges in the middle. Therefore, the liquid film keeps in contact with the wafer surface, and the liquid film volatilizes with the contact liquid film on the exposed wafer to realize mark-free drying. However, in actual operation, the speed of liquid level drop changes with the change of pressure, and the bottom discharge is easy to produce upwelling bubbles, which greatly increases the probability of liquid level fluctuation. Based on the liquid level fluctuation, the cleaning liquid is easy to climb up along the wafer surface to be cleaned and form an angle, thus greatly increasing the probability of water marks on the wafer surface. SUMMARY

[0007] The present application solves the technical problems of overcoming the deficiencies of the prior art and providing an improved wafer surface cleaning device.

[0008] To solve the above technical problems, the present application adopts the following technical solutions:

[0009] The wafer surface cleaning device comprises a cleaning tank, wherein a wafer carrier is inserted into the cleaning tank along the up-down direction, and a wafer surface to be cleaned is immersed in a cleaning liquid; the cleaning device further comprises an overflow mechanism and a surface-to-be-cleaned processing mechanism arranged in sequence from bottom to top and moving synchronously, wherein the overflow mechanism is formed with an overflow passage; the surface-to-be-cleaned processing mechanism is formed with a plurality of gas streams generated by gasification of liquid and easy to evaporate, wherein the plurality of gas streams comprises a first gas stream blowing towards the surface-to-be-cleaned exposed to the surface of the cleaning liquid to form dryness, and a second gas stream blowing towards the junction of the surface of the cleaning liquid and the surface-to-be-cleaned to form a liquid film gradually covering the surface of the cleaning liquid; as the overflow mechanism moves downward, the cleaning liquid is discharged from the overflow passage, and the first and second gas streams blow and cooperate simultaneously to make the surface of the cleaning liquid near the junction keep vertical to the surface-to-be-cleaned and gradually dry the surface-to-be-cleaned from top to bottom. That is, the application controls the descending speed of the surface of the cleaning liquid based on the downward movement of the overflow mechanism to form a stable liquid surface, and through the blowing and cooperation of the first and second gas streams, the surface tension of the cleaning liquid is weakened or eliminated, the tendency of the cleaning liquid to climb along the wafer surface is inhibited in the descending of the liquid surface, the surface of the cleaning liquid near the junction keeps vertical to the surface-to-be-cleaned, thereby reducing the probability of the cleaning liquid remaining on the wafer surface in a large range, and as the surface of the cleaning liquid descends, the area of the exposed part gradually increases, the second gas stream covers the entire exposed part to form dryness under the continuous assistance of the liquid film, and the gas evaporation on the wafer surface takes away the surface residual water droplets to realize traceless drying.

[0010] According to a specific implementation and preferred aspect of the application, the overflow mechanism comprises an overflow tank arranged on one side of the surface-to-be-cleaned and forming an overflow port, a liquid collecting tank arranged below the overflow tank, and an overflow pipeline communicating the overflow tank and the liquid collecting tank and capable of synchronous expansion and contraction with the up-down movement of the overflow tank, wherein the overflow tank, the overflow pipeline and the liquid collecting tank form the overflow passage.

[0011] Preferably, the overflow port comprises a plurality of overflow notches distributed along the width direction of the cleaning tank, and the cleaning liquid is divided into multiple streams through the plurality of overflow notches and enters the overflow tank. Here, based on the division and buffering of the plurality of overflow notches, the smoothness of the overflow discharge of the cleaning liquid is effectively improved, and the fluctuation generated by the liquid discharge is further reduced to ensure the stability of the Marangoni effect.

[0012] Preferably, the overflow tank comprises a first side tank plate and a second side tank plate arranged in sequence from inside to outside along the thickness direction of the cleaning tank, a tank end plate connected between the opposite sides of the first side tank plate and the second side tank plate, and a tank bottom plate connected between the bottoms of the first side tank plate and the second side tank plate, wherein the first side tank plate is formed with a plurality of comb teeth distributed along the width direction of the cleaning tank from the top, and each adjacent two comb teeth form an overflow notch; the overflow pipeline is connected between the tank bottom plate and the liquid collecting tank. Here, the structure is simple and convenient for assembly and implementation.

[0013] Specifically, the first side groove plate is bent from the top to the direction away from the surface to be cleaned and forms a bending part, and a plurality of comb teeth are distributed at the end of the bending part away from the surface to be cleaned. Here, the overflow gap is away from the surface to be cleaned, thereby further reducing the fluctuation of the cleaning liquid surface near the surface to be cleaned generated by liquid discharge.

[0014] Further, the groove bottom plate extends up and down in the width direction of the cleaning tank, and the overflow pipe is connected to the lower part of the groove bottom plate; and / or, the overflow pipe comprises a plurality of pipe parts successively sleeved from top to bottom, and the diameters of the plurality of pipe parts gradually increase from top to bottom. Here, it is convenient for the discharge and collection of cleaning liquid.

[0015] According to another specific implementation and preferred aspect of the present application, the multiple air streams use isopropyl alcohol, the first air stream is sprayed onto the surface to be cleaned and replaces the residual cleaning liquid, and the second air stream is sprayed at the junction of the cleaning liquid surface and the surface to be cleaned and gradually forms an isopropyl alcohol liquid film covering the cleaning liquid surface in the overflow direction. Here, the volatile nature of isopropyl alcohol (IPA) is used to replace the residual cleaning liquid on the wafer surface to improve the drying effect; at the same time, based on the isopropyl alcohol liquid film formed to cover the cleaning liquid surface, the surface tension of the cleaning liquid is reduced, which is conducive to the stable formation of the Marangoni effect.

[0016] Preferably, the surface to be cleaned processing mechanism comprises a spraying module fixedly connected to the top of the overflow tank and an air stream supply part, wherein a main cavity in communication with the air stream supply part is formed in the spraying module, a first sub-cavity and a second sub-cavity are arranged on one side of the main cavity and are in communication with the main cavity, and the air stream enters the main cavity and is then divided into the first sub-cavity and the second sub-cavity to form the first air stream and the second air stream. Here, the same cavity is used to divide the air stream into the first and second air streams, which not only facilitates the simplification of the structure and the realization of compact structure, but also facilitates the stable output of the air stream.

[0017] Specifically, the volume of the first sub-cavity is greater than that of the second sub-cavity, and the flow rate of the first air stream sprayed from the first sub-cavity is less than that of the second air stream sprayed from the second sub-cavity. Here, by controlling the volume difference between the first and second sub-cavities, the flow rates of the first and second air streams are controlled, thereby accurately controlling the flow of the multiple air streams blown to the wafer surface (to avoid damage to the wafer surface caused by excessive isopropyl alcohol air stream) and ensuring the formation of a uniform IPA liquid film on the cleaning liquid surface.

[0018] Preferably, the main cavity is formed with a first flow dividing hole and a second flow dividing hole in communication with the first sub-cavity and the second sub-cavity, respectively, and the first sub-cavity and the second sub-cavity correspondingly form a first spraying port and a second spraying port from one side, wherein the first flow dividing hole and the first spraying port are distributed in a staggered manner from top to bottom, and the second flow dividing hole and the second spraying port are distributed in a staggered manner from top to bottom. Here, the first and second air streams after being divided form stable spraying air pressure in the corresponding sub-cavities, so as to ensure the stable output of the first and second air streams.

[0019] Specifically, the first gas flow is perpendicular to the surface to be cleaned, and the second gas flow is inclined up and down.

[0020] Further, the first and second injection ports respectively extend along the width direction of the cleaning tank, and in the orthographic projection on the surface to be cleaned, the two ends of the first and second injection ports respectively protrude out of the surface to be cleaned or the sealing ring or the wafer carrier. Here, the gas flow can cover the entire wafer surface and there is no uneven coverage and the gas plane height is not uniform.

[0021] Preferably, in the orthographic projection on the surface of the cleaning liquid, the second injection port is located between the overflow port and the surface to be cleaned. Here, the gas flow is ensured to form a liquid film on the surface of the cleaning liquid.

[0022] According to another specific implementation and preferred aspect of the present application, the front and back surfaces of the wafer carrier are respectively loaded with a wafer; the overflow tank and the injection module constitute a drying group, and there are two drying groups and the two drying groups simultaneously dry the surfaces to be cleaned of two wafers. Here, it is beneficial to improve the cleaning and drying efficiency.

[0023] In addition, the cleaning device further comprises a power mechanism for driving the two drying groups to move up and down synchronously.

[0024] Due to the implementation of the above technical solutions, the present application has the following advantages compared with the prior art:

[0025] In the drying process of the existing wafer cleaning, if high-purity nitrogen is used for drying, it is mainly based on the unloading of the soaking liquid. The exposed wafer is dried by blowing high-purity nitrogen. Although it seems simple and efficient on the surface, when the gas acts on the position of the wafer surface with large water droplets, it will cause the water droplets to splash, causing the already dried position to introduce water droplets again, and after being dried again, water marks will be formed. It is very difficult to clean, and if not cleaned deeply with chemical liquid, it will cause the wafer to be scrapped. If the drying method based on the Marangoni principle is used, it mainly uses two liquids with different surface tensions to contact, based on the surface liquid film (also known as IPA liquid film or isopropyl alcohol liquid film) to keep flowing from the area with low surface tension to the area with high surface tension. At the same time, as the liquid level drops, the water flow converges to the middle, so the liquid film keeps in contact with the wafer surface, and as the exposed liquid film on the wafer volatilizes, it takes away the residual water droplets on the surface, achieving mark-free drying. However, in actual operation, the speed of liquid level drop changes with pressure, so the probability of liquid level fluctuation increases greatly, and based on the liquid level fluctuation, the cleaning liquid is easy to climb up along the wafer surface to be cleaned and form an angle, so the probability of water marks on the wafer surface also increases greatly. And so on. The structure of the wafer surface cleaning device is designed as a whole, and the deficiencies and defects of the prior art are ingeniously solved. After using the cleaning device, the wafer carrier loaded with wafers is inserted into the cleaning tank from top to bottom, so that the wafer surface to be cleaned is immersed in the cleaning liquid for cleaning. Then drive the overflow mechanism and the surface to be cleaned processing mechanism to move synchronously from top to bottom, wherein the overflow passage formed by the overflow mechanism enables the cleaning liquid to be discharged from the overflow passage synchronously with the downward movement of the overflow mechanism to accurately control the descending speed of the cleaning liquid surface. At the same time, the surface to be cleaned processing mechanism forms a first airflow blowing to the surface to be cleaned exposed to the cleaning liquid to form a dry first airflow, a second airflow blowing to the intersection of the cleaning liquid surface and the surface to be cleaned to form a liquid film gradually covering the cleaning liquid surface, and the first and second airflows are blown and cooperated at the same time to make the cleaning liquid surface close to the intersection keep vertical to the surface to be cleaned (reduce the probability of large-scale residual cleaning liquid along the wafer surface) and gradually dry the small amount of cleaning liquid remaining in the surface to be cleaned from top to bottom.Therefore, compared with the prior art, the present application, on one hand, abandons the conventional use of the gravity of water as a drive to control the water surface to descend, and realizes the accurate control of the descending speed of the cleaning liquid surface by adopting the overflow mode and cooperating with the obstruction formed by the surface liquid film, so as to ensure that the cleaning liquid surface remains stable; on the other hand, by the synchronous downward movement of the overflow mechanism and the surface to be cleaned processing mechanism, the spraying height of the airflow relative to the cleaning liquid surface is always unchanged, the cleaning liquid is overflowed and discharged, and then the first and second airflows are blown and cooperated to keep the cleaning liquid surface perpendicular to the wafer surface to be cleaned and form a liquid film which is not affected by the liquid level fluctuation, so as to effectively inhibit the tendency of the cleaning liquid to climb along the wafer surface, thereby reducing the probability of the cleaning liquid remaining on the wafer surface in a large range and gradually realizing the traceless drying of the wafer surface from top to bottom. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a schematic diagram of the three-dimensional structure of the wafer surface cleaning device of the present application;

[0027] Figure 2 It is a schematic diagram of the three-dimensional structure of the wafer surface cleaning device of the present application; Figure 1

[0028] Figure 3 It is a schematic diagram of the three-dimensional structure of the wafer surface cleaning device of the present application;

[0029] Figure 4 It is a schematic diagram of the three-dimensional structure of the wafer surface cleaning device of the present application; Figure 3

[0030] It is a schematic diagram of the three-dimensional structure of the wafer surface cleaning device of the present application; Figure 5 Figure 2 It is a schematic diagram of the three-dimensional structure of the wafer surface cleaning device of the present application;

[0031] Figure 6 Figure 5 It is a schematic diagram of the three-dimensional structure of the wafer surface cleaning device of the present application;

[0032] Figure 7 It is a schematic diagram of the three-dimensional structure of the wafer surface cleaning device of the present application; Figure 4

[0033] 1, cleaning tank;

[0034] 2, overflow mechanism; 20, overflow tank; 201, first side tank plate; b, bending part; c, comb tooth; s0, overflow gap; k0, overflow port; 202, second side tank plate; 203, tank end plate; 204, tank bottom plate; 21, liquid collecting tank; 22, overflow pipeline; 220, pipeline split body;

[0035] 3, surface to be cleaned processing mechanism; 30, spraying module; 300, main cavity; k1, first shunt hole; k2, second shunt hole; 301, first sub-cavity; k3, first spraying port; 302, second sub-cavity; k4, second spraying port; 31, airflow supply part; m, connecting module;​​​​

[0036] 4. power mechanism;

[0037] J. wafer carrier; Y. wafer. DETAILED DESCRIPTION

[0038] In order to make the above objectives, features and advantages of the present application more clear and easily understood, the specific embodiments of the present application will be described in detail below with the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of different ways from those described herein without departing from the scope of the present application, and it is understood that similar improvements to those described herein will occur to those skilled in the art. Therefore, the present application is not intended to be limited to the specific embodiments disclosed below, but it is intended to include all modifications falling within the scope of the present application.

[0039] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0040] In addition, the terms "first", "second", "third" and the like are used only for descriptive purposes and should not be construed as indicating or implying relative importance or a specific number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified and limited.

[0041] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0042] In the present application, unless otherwise explicitly specified and limited, a first feature is "on" or "under" a second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature is "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the first feature is higher in horizontal height than the second feature. The first feature is "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the first feature is lower in horizontal height than the second feature.

[0043] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there can be an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there can be an intervening element. The terms "vertical", "horizontal", "upper", "lower", "left", "right", and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation.

[0044] As shown in Figures 1 to 7 The wafer surface cleaning device of the present embodiment includes a cleaning tank 1, an overflow mechanism 2 and a surface-to-be-cleaned processing mechanism 3. The front and back surfaces of the wafer carrier J are loaded with a wafer Y respectively.

[0045] Specifically, the cleaning tank 1 is open at the top and forms an inlet and outlet. The wafer carrier J is inserted into the cleaning tank 1 along the up-down direction, and the surface-to-be-cleaned of the wafer Y is soaked in the cleaning liquid. In some specific embodiments, the cleaning tank 1 can be a wafer cleaning tank of any conventional structure, and the cleaning liquid used in the present application is water with a temperature of 30-50°C. In the present embodiment, the temperature of the cleaning liquid is preferably 40°C.

[0046] In the present embodiment, the overflow mechanism 2 and the surface-to-be-cleaned processing mechanism 3 are arranged in sequence from bottom to top and move synchronously. The overflow mechanism 2 includes an overflow tank 20 forming an overflow port k0, a liquid collecting tank 21 arranged below the overflow tank 20, and an overflow pipeline 22 communicating the overflow tank 20 and the liquid collecting tank 21 and capable of synchronous expansion and contraction with the up-down movement of the overflow tank 20, wherein the overflow tank 20, the overflow pipeline 22 and the liquid collecting tank 21 form an overflow passage. The surface-to-be-cleaned processing mechanism 3 includes a spraying module 30 fixedly connected to the top of the overflow tank 20 and an air supply component 31. The overflow tank 20 and the spraying module 30 form a drying group. There are two drying groups and they are arranged on the side of the surface-to-be-cleaned of each wafer Y. The two drying groups form a processing cavity. The wafer carrier penetrates into the processing cavity from top to bottom. The two drying groups dry the surface-to-be-cleaned of the two wafers synchronously.

[0047] The following takes one side of the drying group as an example, and the drying of the single wafer cleaning surface is carried out. The cleaning surface processing mechanism 3 is formed by a plurality of gas streams generated by the gasification of liquid and easy to volatilize. The plurality of gas streams include a first gas stream blowing to the cleaning surface exposed to the cleaning liquid surface to form drying, and a second gas stream blowing to the junction of the cleaning liquid surface and the cleaning surface to form a liquid film gradually covering the cleaning liquid surface. With the overflow mechanism 2 descending to discharge the cleaning liquid from the overflow passage, the first and second gas streams are blown and cooperated to make the cleaning liquid surface near the junction keep vertical to the cleaning surface and gradually dry the cleaning surface from top to bottom. That is, the application controls the descending speed of the cleaning liquid surface based on the overflow mechanism to form a stable liquid surface. Through the blowing and cooperation of the first and second gas streams, the surface tension of the cleaning liquid is reduced or eliminated, the tendency of the cleaning liquid to climb along the wafer surface is inhibited in the liquid surface descending, the cleaning liquid surface near the junction is kept vertical to the wafer cleaning surface, thereby reducing the probability of the cleaning liquid remaining on the wafer surface in a large range. At the same time, with the descending of the cleaning liquid surface, the area of the exposed part gradually increases, and the second gas stream covers the entire exposed part to form drying under the continuous assistance of the liquid film, and the gas volatilization on the wafer surface takes away the surface residual water droplets to realize traceless drying.

[0048] In this example, the overflow tank 20 includes a first side tank plate 201 and a second side tank plate 202 arranged in the thickness direction of the cleaning tank 1 from inside to outside, a tank end plate 203 connected between the opposite sides of the first side tank plate 201 and the second side tank plate 202, and a tank bottom plate 204 connected between the bottoms of the first side tank plate 201 and the second side tank plate 202.

[0049] In some embodiments, the first side tank plate 201 is bent from the top to the direction away from the cleaning surface and forms a bent part b, and a plurality of comb teeth c are arranged on the end part of the bent part b away from the cleaning surface and arranged in the width direction of the cleaning tank 1. Each adjacent two comb teeth c forms an overflow gap s0, and a plurality of overflow gaps s0 are arranged in the width direction of the cleaning tank 1 and constitute an overflow port k0. The cleaning liquid is divided by the plurality of overflow gaps s0 and enters the overflow tank 20. Here, based on the plurality of overflow gaps s0, the cleaning liquid is effectively improved in the smoothness of the overflow discharge, and the fluctuation generated by the liquid discharge is further reduced to ensure the stability of the Marangoni effect. At the same time, the overflow gap is away from the cleaning surface, thereby further reducing the fluctuation of the cleaning liquid surface near the cleaning surface generated by the liquid discharge.

[0050] Meanwhile, the groove bottom plate 204 extends upward and downward in the width direction of the cleaning tank 1, the overflow pipe 22 is connected to the lower part of the groove bottom plate 204 from the upper end and connected to the liquid collecting tank 21 from the lower end; the overflow pipe 22 includes a plurality of pipe parts 220 which are sequentially sleeved from top to bottom, and the diameters of the plurality of pipe parts 220 gradually increase from top to bottom; the cleaning tank 1 of the embodiment can be provided in multiple and arranged side by side above the liquid collecting tank 21, so as to realize that a single liquid collecting tank 21 synchronously receives the overflow cleaning liquid of a plurality of cleaning tanks 1 in the batch implementation of the wafer cleaning and drying process.

[0051] In the example, the gas flow is isopropyl alcohol, the first gas flow is sprayed onto the surface to be cleaned and replaces the residual cleaning liquid, and the second gas flow is sprayed at the junction of the cleaning liquid surface and the surface to be cleaned and gradually forms an isopropyl alcohol liquid film covering the cleaning liquid surface along the overflow direction. Here, the volatile nature of isopropyl alcohol (IPA) is used to replace the residual cleaning liquid on the wafer surface to improve the drying effect; at the same time, based on the isopropyl alcohol liquid film formed to cover the cleaning liquid surface, the surface tension of the cleaning liquid is reduced, which is conducive to the stable formation of the Marangoni effect.

[0052] In some specific embodiments, a main cavity 300 is formed in the spray module 30 and is in communication with the gas flow supply part 31, a first sub-cavity 301 and a second sub-cavity 302 are arranged on one side of the main cavity 300 and are in communication with the main cavity 300, respectively, and the gas flow enters the main cavity 300 and is divided into the first sub-cavity 301 and the second sub-cavity 302 to form the first gas flow and the second gas flow. Here, the same cavity is used to divide the flow to form the first and second gas flows, which not only facilitates the simplification of the structure and the realization of the compact structure, but also facilitates the stable output of the gas flow.

[0053] Meanwhile, the volume of the first sub-cavity 301 is greater than the volume of the second sub-cavity 302 (the two are flush with the side wall, and the height of the first sub-cavity 301 is greater than the height of the second sub-cavity 302), and the flow rate of the first gas flow sprayed from the first sub-cavity 301 is less than the flow rate of the second gas flow sprayed from the second sub-cavity 302. Here, by controlling the volume difference of the first and second sub-cavities, the flow rates of the first and second gas flows are controlled, so as to accurately control the multiple gas flows blown to the wafer surface (avoiding excessive isopropyl alcohol gas flow to damage the wafer surface), and ensure the formation of a uniform IPA liquid film on the cleaning liquid surface.

[0054] To further facilitate the implementation, the main cavity 300 is formed with a first flow hole k1 and a second flow hole k2 respectively connected with the first sub-cavity 301 and the second sub-cavity 302, and the first sub-cavity 301 and the second sub-cavity 302 are formed with a first jet port k3 and a second jet port k4 on the corresponding side, wherein the first flow hole k1 and the first jet port k3 are distributed in the up-down staggered manner, and the second flow hole k2 and the second jet port k4 are distributed in the up-down staggered manner. Here, the first and second air flows after the flow distribution form stable jet air pressure in the corresponding sub-cavities to ensure the stable output of the first and second air flows.

[0055] Specifically, the first air flow is perpendicular to the surface to be cleaned along the flow direction formed by the first jet port k3, and the second air flow is inclined up and down along the flow direction formed by the second jet port k4; the first jet port k3 and the second jet port k4 extend along the width direction of the cleaning tank 1, and in the orthographic projection on the surface to be cleaned, the two ends of the first jet port k3 and the second jet port k4 respectively protrude from the surface to be cleaned, the sealing ring or the wafer carrier. Here, it is ensured that multiple air flows can cover the entire wafer surface without uneven coverage and different gas plane heights.

[0056] At the same time, in the orthographic projection on the cleaning liquid surface, the second jet port k4 is located between the overflow port k0 and the surface to be cleaned. Here, it is ensured that the air flow is formed on the liquid film on the surface of the cleaning liquid.

[0057] In this example, the air flow supply component 31 adopts any conventional isopropyl alcohol supply device, and is connected to the two ends of each jet module 30 through the connection module m and is connected with the main cavity 300.

[0058] In addition, the cleaning device of the embodiment further includes a power mechanism 4 for driving the synchronous lifting motion of the two drying groups, and the power mechanism 4 includes telescopic power rods arranged on the opposite sides of the cleaning tank 1 and connected with the two ends of the jet module 30, and the synchronous up-down motion of the overflow groove 20 and the jet module 30 is driven by the telescopic motion of the telescopic power rods.

[0059] In summary, after adopting the cleaning device, the wafer carrier loaded with wafers is inserted into the cleaning tank from top to bottom, so that the surface to be cleaned formed by the wafer is immersed in the cleaning liquid for cleaning; then the overflow mechanism and the surface to be cleaned processing mechanism are driven to move synchronously from top to bottom, wherein the overflow channel formed by the overflow mechanism enables the cleaning liquid to be discharged from the overflow channel synchronously with the downward movement of the overflow mechanism to accurately control the descending speed of the cleaning liquid level; at the same time, the surface to be cleaned processing mechanism forms a first airflow that blows toward the surface to be cleaned exposed to the cleaning liquid surface to form a dry first airflow, and blows toward the junction of the cleaning liquid surface and the surface to be cleaned to form a liquid film that gradually covers the cleaning liquid surface; the first and second airflows simultaneously blow and cooperate to make the cleaning liquid surface near the junction remain perpendicular to the surface to be cleaned (reducing the probability of the cleaning liquid climbing along the wafer surface and remaining in a large range) and gradually dry the small amount of cleaning liquid remaining on the surface to be cleaned from top to bottom. Therefore, compared with the prior art, the present invention, on the one hand, abandons the conventional use of the gravity of water as a drive to control the descent of the water level, and adopts an overflow method, combined with the obstruction formed by the surface liquid film, to achieve precise control of the descending speed of the cleaning liquid level, thereby ensuring that the cleaning liquid level remains stable; on the other hand, through the synchronous downward movement of the overflow mechanism and the surface processing mechanism to be cleaned, the cleaning liquid overflow is discharged with the jet height of the airflow relative to the cleaning liquid level always unchanged, and then the first and second airflows are purged and cooperated to keep the cleaning liquid level at the junction perpendicular to the wafer surface to be cleaned and form a liquid film that is not affected by liquid level fluctuations, effectively inhibiting the tendency of the cleaning liquid to climb along the wafer surface, thereby reducing the probability of the cleaning liquid remaining on the wafer surface in a large range and gradually achieving traceless drying of the wafer surface from top to bottom; thirdly, based on multiple overflow notches to divert and form a buffer, the smoothness of the overflow discharge of the cleaning liquid is effectively improved, and the discharge of the cleaning liquid is further reduced. Fluctuations ensure the stability of the Marangoni effect; fourthly, the volatility of isopropyl alcohol (IPA) is used to replace the residual cleaning liquid on the wafer surface to improve the drying effect; at the same time, based on the isopropyl alcohol liquid film formed to cover the cleaning liquid surface, the surface tension of the cleaning liquid is weakened, which is conducive to the stable formation of the Marangoni effect; fifthly, based on the same cavity, the diversion is implemented to form the first and second airflows, which is not only conducive to simplifying the structure, achieving a compact structure, and facilitating the control of stable airflow output, but also by controlling the volume difference between the first and second sub-cavities, the flow rate of the first and second airflows is controlled, thereby accurately controlling the airflow flow rate blown to the wafer surface (avoiding excessive isopropyl alcohol airflow and causing damage to the wafer surface), and ensuring the formation of a uniform IPA liquid film on the cleaning liquid surface; sixthly, the design of the nozzle of the present application is adopted to ensure that multiple airflows can cover the entire wafer surface without uneven coverage and different heights of the formed gas planes.

[0060] The above has made the detailed description to the application, its purpose is in order to let the person who is familiar with this field technology can understand the content of the application and implements, and cannot limit the protection scope of the application with this, all according to the spirit of the application of equivalent change or modification, should be covered in the protection scope of the application.

Claims

1. A wafer surface cleaning apparatus comprising a cleaning tank in which a wafer carrier is inserted in the cleaning tank in the up-and-down direction, and a surface of a wafer formed on the wafer carrier is immersed in a cleaning liquid, characterized in that, The cleaning device further comprises an overflow mechanism and a surface-to-be-cleaned processing mechanism arranged in sequence from bottom to top and moving synchronously, wherein the overflow mechanism is formed with an overflow passage; the surface-to-be-cleaned processing mechanism is formed with a plurality of gas streams which are gaseous and volatile, wherein the plurality of gas streams include a first gas stream blowing towards the surface-to-be-cleaned exposed to the cleaning liquid to form a dry surface, and a second gas stream blowing towards the intersection of the cleaning liquid surface and the surface-to-be-cleaned to form a liquid film gradually covering the cleaning liquid surface; the cleaning liquid is discharged from the overflow passage with the downward movement of the overflow mechanism; the downward movement of the overflow mechanism controls the descending speed of the cleaning liquid surface to ensure that the cleaning liquid surface remains stable; and the first and second gas streams blow simultaneously and cooperatively to keep the cleaning liquid surface near the intersection perpendicular to the surface-to-be-cleaned and gradually dry the surface-to-be-cleaned from top to bottom. ​ 2. The wafer surface cleaning apparatus of claim 1, wherein The overflow mechanism comprises an overflow tank arranged on one side of the surface-to-be-cleaned and forming an overflow port, a liquid collecting tank arranged below the overflow tank, and an overflow pipeline connected with the overflow tank and the liquid collecting tank and capable of synchronous expansion and contraction with the upward and downward movement of the overflow tank, wherein the overflow tank, the overflow pipeline and the liquid collecting tank form the overflow passage.

3. The wafer surface cleaning apparatus of claim 2, wherein The overflow port comprises a plurality of overflow gaps distributed along the width direction of the cleaning tank, and the cleaning liquid is distributed through the plurality of overflow gaps and enters the overflow tank.

4. The wafer surface cleaning apparatus of claim 3, wherein The overflow tank comprises a first side tank plate and a second side tank plate arranged in sequence from inside to outside along the thickness direction of the cleaning tank, a tank end plate connected between the opposite sides of the first side tank plate and the second side tank plate, and a tank bottom plate connected between the bottoms of the first side tank plate and the second side tank plate, wherein the first side tank plate is formed with a plurality of comb teeth distributed along the width direction of the cleaning tank from the top, and each adjacent two comb teeth form the overflow gap; and the overflow pipeline is connected between the tank bottom plate and the liquid collecting tank.

5. The wafer surface cleaning apparatus of claim 4, wherein The first side tank plate is bent away from the surface-to-be-cleaned from the top and forms a bent portion, and the plurality of comb teeth are distributed at the end of the bent portion away from the surface-to-be-cleaned.

6. The wafer surface cleaning apparatus of claim 4, wherein The tank bottom plate extends up and down along the width direction of the cleaning tank, and the overflow pipeline is connected to the lower part of the tank bottom plate; and / or the overflow pipeline comprises a plurality of pipeline parts connected in sequence from top to bottom, and the diameters of the plurality of pipeline parts gradually increase from top to bottom.

7. The wafer surface cleaning apparatus of claim 1, wherein The plurality of gas streams use isopropyl alcohol, the first gas stream is sprayed onto the surface-to-be-cleaned to replace the residual cleaning liquid, and the second gas stream is sprayed to the intersection of the cleaning liquid surface and the surface-to-be-cleaned to gradually form an isopropyl alcohol liquid film covering the cleaning liquid surface along the overflow direction.

8. The wafer surface cleaning apparatus of claim 2, wherein The surface-to-be-cleaned processing mechanism comprises a spraying module fixedly connected to the top of the overflow tank and a gas stream supply component, wherein the spraying module is formed with a main cavity connected with the gas stream supply component, a first sub-cavity and a second sub-cavity arranged on one side of the main cavity in sequence from top to bottom and connected with the main cavity, and the gas stream entering the main cavity is distributed into the first sub-cavity and the second sub-cavity to form the first gas stream and the second gas stream.

9. The wafer surface cleaning apparatus of claim 8, wherein The volume of the first sub-cavity is greater than that of the second sub-cavity, and the flow rate of the first gas stream sprayed from the first sub-cavity is less than that of the second gas stream sprayed from the second sub-cavity.

10. The wafer surface cleaning apparatus of claim 8, wherein The first and second sub-flow holes are formed on the main cavity and communicate with the first and second sub-cavities respectively, and the first and second sub-cavities correspondingly form the first and second injection ports respectively, wherein the first sub-flow hole is distributed vertically with the first injection port, and the second sub-flow hole is distributed vertically with the second injection port.

11. The wafer surface cleaning apparatus of claim 10, wherein The first airflow is perpendicular to the surface to be cleaned along the flow direction formed by the first injection port, and the second airflow is inclined up and down along the flow direction formed by the second injection port.

12. The wafer surface cleaning apparatus of claim 10, wherein The first and second injection ports respectively extend along the width direction of the cleaning tank, and in the orthographic projection on the surface to be cleaned, the two ends of the first and second injection ports respectively protrude from the surface to be cleaned or the wafer carrier.

13. The wafer surface cleaning apparatus of claim 10, wherein, In the orthographic projection on the surface of the cleaning liquid, the second injection port is located between the overflow port and the surface to be cleaned.

14. The wafer surface cleaning apparatus of claim 2, wherein The front and back surfaces of the wafer carrier are respectively loaded with a wafer; the overflow tank and the injection module constitute a drying group, and there are two drying groups which synchronously dry the surfaces to be cleaned of two wafers.

15. The wafer surface cleaning apparatus of claim 14, wherein The cleaning device further comprises a power mechanism for driving the synchronous lifting movement of the two drying groups.

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