A cleaning apparatus and cleaning method for a semiconductor wafer

Abstract

This invention relates to a semiconductor wafer cleaning apparatus and method, comprising a feeding assembly, a plasma cavitation assembly, and a spray assembly. The plasma cavitation assembly includes a housing and a reaction mechanism, the reaction mechanism being located within the housing. A reaction channel is provided within the housing, and multiple reaction mechanisms are arranged along the transport path of the reaction channel. Each reaction mechanism includes a plasma reaction unit and a cavitation unit, arranged along the transport path of the reaction channel. The output end of the feeding assembly is connected to the input end of the reaction channel. The input end of the spray assembly is connected to the output end of the reaction channel. This invention provides a semiconductor wafer cleaning apparatus and method, which improves wafer cleaning efficiency.

Description

Technical Field

[0001] This invention relates to the field of cleaning equipment technology, and in particular to a cleaning device and cleaning method for semiconductor wafers. Background Technology

[0002] As semiconductor manufacturing processes advance towards higher integration and smaller feature sizes, the surface cleanliness of wafers has an increasingly significant impact on the performance and yield of semiconductor devices. During wafer manufacturing, residual particulate contaminants, organic contaminants, or metallic impurities on the wafer surface can easily adversely affect subsequent processes.

[0003] Ozone, due to its strong oxidizing ability, is widely used in the cleaning and etching processes of semiconductor manufacturing. In existing technologies, ozone is usually used in the wafer cleaning process in the form of ozone water. By decomposing in the aqueous phase, the active oxygen substances generated oxidize and decompose organic contaminants and photolithography residues on the wafer surface, transforming them into easily removable forms, thereby achieving the cleaning of the wafer surface.

[0004] However, ozone is unstable in gaseous or liquid environments and is prone to decomposition. Its cleaning effectiveness largely depends on the ozone generation method, dissolution efficiency, and effective concentration upon reaching the wafer surface. While hydrocavitation and plasma discharge offer advantages in enhancing active material generation and improving cleaning reactivity, respectively, in existing technologies, ozone generation, plasma discharge, and hydrocavitation processes are often independently configured with limited synergy. Typically, ozone is generated by a separate ozone generator and then transported via pipeline to the cleaning chamber or spray assembly for use. During transport, ozone is prone to decomposition in gaseous or liquid environments, leading to a decrease in ozone concentration entering the cleaning area. This limits the effective amount of ozone participating in the cleaning reaction, resulting in energy waste and restricting the full utilization of ozone oxidation. Therefore, there is still room for improvement in wafer cleaning efficiency. This invention, which fully mixes microbubbles with water and utilizes plasma and cavitation technologies in a microchannel environment to synergistically generate active materials, has significant application value in wafer surface cleaning. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to provide a cleaning apparatus and cleaning method for semiconductor wafers, which can improve the cleaning efficiency of wafers.

[0006] To address the aforementioned technical problems, this invention provides a cleaning apparatus for semiconductor wafers, comprising a feeding assembly, a plasma cavitation assembly, and a spray assembly. The plasma cavitation assembly includes a housing and a reaction mechanism, the reaction mechanism being located within the housing. A reaction channel is provided within the housing, and multiple reaction mechanisms are arranged along the transport path of the reaction channel. Each reaction mechanism includes a plasma reaction unit and a cavitation unit, which are arranged along the transport path of the reaction channel. The output end of the feeding assembly is connected to the input end of the reaction channel; the input end of the spray assembly is connected to the output end of the reaction channel.

[0007] In one embodiment of the present invention, the plasma reaction unit includes a first electrode and a second electrode, the reaction channel is located between the first electrode and the second electrode, the first electrode has a first protrusion on the side near the second electrode, the sidewall of the first protrusion is arc-shaped, the second electrode has a groove on the side near the first electrode corresponding to the position of the first protrusion, and the distance between the first electrode and the second electrode and the distance between the first protrusion and the groove are kept equal along the transport path.

[0008] In one embodiment of the present invention, the plasma reaction unit further includes a first dielectric barrier layer and a second dielectric barrier layer, wherein the first dielectric barrier layer is located on the side of the first electrode close to the second electrode, and the second dielectric barrier layer is located on the side of the second electrode close to the first electrode.

[0009] In one embodiment of the present invention, the cavitation unit includes a first cavitation element and a second cavitation element, the reaction channel is located between the first cavitation element and the second cavitation element, and both the first cavitation element and the second cavitation element are provided with a second protrusion extending into the reaction channel.

[0010] In one embodiment of the present invention, an impeller is further included. The housing includes a first housing and a second housing. The first housing is connected to the second housing. The reaction mechanism is located inside the first housing. The second housing has a housing space. The impeller is located inside the housing space. The impeller is rotatably connected to the side wall of the second housing. The impeller has an output port facing the input end of the reaction channel. The output end of the feeding assembly and the input end of the reaction channel are both connected to the housing space.

[0011] In one embodiment of the present invention, the plasma cavitation assembly further includes a flow path guiding mechanism located between the impeller and the reaction mechanism. The flow path guiding mechanism includes an elastic member and an abutment member. The two ends of the elastic member are respectively connected to the abutment member and the inner wall of the second housing. The abutment member is provided with a third protrusion. The side of the impeller near the reaction mechanism is provided with an annular guide groove. The third protrusion is slidably connected to the guide groove.

[0012] In one embodiment of the present invention, the feeding assembly includes a liquid pump, an air pump, and a mixing component. The output ends of the liquid pump and the air pump are both connected to the mixing component, and the output end of the mixing component is connected to the input end of the reaction channel.

[0013] In one embodiment of the present invention, a support component is further included, the support component including a tray and a clamping member, the tray including a support space, the bottom of the support space being provided with a plurality of drainage holes, the clamping member being hinged to the edge of the tray, and the spraying component including a plurality of spraying members, the spraying ends of the spraying members facing the support space.

[0014] In one embodiment of the present invention, a flipping component is further included, wherein the execution end of the flipping component can extend into the carrying space.

[0015] This invention also provides a wafer cleaning method, which uses the above-mentioned semiconductor wafer cleaning apparatus to clean the wafer, including the following steps: Step S1: The feeding component introduces air into the reaction channel, filling the reaction channel with air; Step S2: The plasma reaction unit ionizes the air, forming an active substance containing ozone in the reaction channel; Step S3: The feeding component introduces a liquid containing bubbles into the reaction channel, the liquid flows along the reaction channel, the plasma reaction unit ionizes the bubbles in the liquid, and the cavitation unit cavitates the liquid, generating an active substance containing ozone in the liquid; Step S4: The liquid containing the active substance cleans the wafer by passing through the spraying component.

[0016] Compared with the prior art, the above-described technical solution of the present invention has the following advantages:

[0017] 1. Multiple reaction mechanisms are arranged along the transport path of the reaction channel, and the reaction mechanism includes reaction units and cavitation units arranged along the transport path of the reaction channel, so that the liquid containing bubbles in the reaction channel can alternately undergo bubble ionization and liquid cavitation. During the continuous flow process, the liquid containing bubbles alternately undergoes bubble ionization and liquid cavitation along the predetermined transport path, forming an ozone generation and dissolution mechanism coupled with the liquid flow process.

[0018] 2. By alternating between bubble ionization and liquid cavitation, ozone can be formed in segments during the liquid flow. Each time ozone is formed, it can be accelerated to dissolve through the cavitation unit, thereby avoiding local saturation and rapid decay caused by concentrated ozone formation.

[0019] 3. By alternating between bubble ionization and liquid cavitation, ozone can be segmented and dissolved instantly, thereby reducing the peak instantaneous concentration of ozone in local areas, slowing down the decomposition rate of ozone, and extending the effective existence time of ozone in the liquid. This enhances the effective existence time of ozone in the liquid, strengthens the ozone generation efficiency and the dissolution efficiency in the liquid, and increases the ozone concentration of the liquid sprayed by the spray component, thereby improving the cleaning efficiency of the wafer. The plasma cavitation component completes the generation, dissolution and transport of ozone under controlled flow conditions, so that the generated ozone liquid matches the wafer cleaning process in terms of cleanliness, uniformity and reaction intensity.

[0020] 4. By designing the impeller, the blades shear and entrain the liquid containing bubbles during rotation. The gas entering the impeller is cut into tiny bubbles and uniformly mixed with the liquid, thus forming a uniform and stable gas-liquid two-phase mixture. After the uniformly mixed gas-liquid mixture enters the reaction channel, the flow distribution, gas-liquid phase state, and stability are effectively improved, thereby improving the uniformity of discharge in the plasma reaction unit and the stability of the cavitation reaction, and further enhancing the generation efficiency of ozone and active substances. Attached Figure Description

[0021] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0022] Figure 1 This is a front view schematic diagram of a cleaning apparatus for semiconductor wafers according to the present invention;

[0023] Figure 2 This is a cross-sectional view of the plasma cavitation assembly;

[0024] Figure 3 This is a cross-sectional view of the reaction mechanism;

[0025] Figure 4 This is a schematic diagram of the impeller structure;

[0026] Figure 5 yes Figure 2 A magnified view of a portion of position A in the middle;

[0027] Figure 6 This is a schematic diagram of the assembly structure of the spray assembly and the plasma cavitation assembly;

[0028] Figure 7This is a schematic diagram of the assembly structure of the spray assembly and the load-bearing assembly;

[0029] Figure 8 This is a structural schematic diagram of the load-bearing component;

[0030] Figure 9 This is a flowchart of a wafer cleaning method.

[0031] Explanation of reference numerals in the accompanying drawings: 1. Liquid pump; 2. Air pump; 3. Impeller; 4. Plasma cavitation assembly; 5. Spray assembly; 6. Support assembly; 7. Wafer to be cleaned; 8. Tilting assembly; 11. Mixing component; 31. Protective shell; 32. Output port; 33. Blade; 34. Connecting shaft; 35. Mixing chamber; 36. Input port; 37. Guide groove; 41. First housing; 42. Second housing; 43. Seal; 44. Bolt; 45. Reaction unit; 46. Cavitation unit; 47. Reaction channel; 48. Flow path. Guide mechanism; 51, first bracket; 52, spray component; 61, second bracket; 62, tray; 63, slot; 64, clamping component; 65, drain trough; 66, drain hole; 411, discharge port; 421, inlet port; 451, first electrode; 452, first protrusion; 453, second electrode; 454, groove; 455, first dielectric barrier layer; 456, second dielectric barrier layer; 461, first cavitation component; 462, second cavitation component; 463, second protrusion; 481, elastic component; 482, abutment component. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0033] Reference Figure 1 and Figure 2 As shown, a semiconductor wafer cleaning apparatus of the present invention includes a feeding assembly, a plasma cavitation assembly, and a spray assembly 5. The plasma cavitation assembly 4 includes a housing and a reaction mechanism. The reaction mechanism is located inside the housing, and a reaction channel 47 is provided inside the housing. A plurality of reaction mechanisms are arranged along the transport path of the reaction channel 47. The reaction mechanism includes a plasma reaction unit 45 and a cavitation unit 46. The plasma reaction unit 45 and the cavitation unit 46 are arranged along the transport path of the reaction channel 47. The output end of the feeding assembly is connected to the input end of the reaction channel 47. The input end of the spray assembly 5 is connected to the output end of the reaction channel 47.

[0034] In this embodiment, a semiconductor wafer cleaning apparatus is used. First, the feeding assembly introduces air into the reaction channel 47, filling it completely. Then, the plasma reaction unit 45 ionizes the air, forming an active substance containing ozone within the reaction channel 47. Next, the feeding assembly introduces a liquid containing bubbles into the reaction channel 47. The liquid flows along the reaction channel 47, the plasma reaction unit 45 ionizes the bubbles in the liquid, and the cavitation unit 46 cavitates the liquid, generating an active substance containing ozone within it. Finally, the liquid containing the active substance passes through the spray assembly 5 to clean the wafer. Multiple reaction mechanisms are arranged along the transport path of the reaction channel 47, and the reaction mechanisms include a plasma reaction unit 45 and a cavitation unit 46 arranged along the transport path of the reaction channel 47. This allows the liquid containing bubbles in the reaction channel 47 to alternately undergo ionization of the bubbles in the liquid and cavitation of the liquid. Ozone can be formed in segments during the liquid flow, and after each ozone formation, it can be accelerated to dissolve by the cavitation unit 46. This avoids local saturation and rapid decay caused by concentrated ozone formation, increases the effective time of ozone in the liquid, increases the ozone concentration of the liquid sprayed by the spray assembly 5, and improves the cleaning efficiency of the wafer.

[0035] Reference Figure 1 As shown, the feeding assembly includes a liquid pump 1, an air pump 2, and a mixer 11. The output ends of both the liquid pump 1 and the air pump 2 are connected to the mixer 11, and the output end of the mixer 11 is connected to the input end of the reaction channel 47. Specifically, the liquid pump 1 is a high-pressure liquid pump 1, and the mixer 11 is a Venturi-type gas-liquid mixer, which includes a Venturi tube. The flow rate of the liquid output by the liquid pump 1 is 1.5 to 2 times the flow rate of the gas output by the air pump 2. The liquid output by the liquid pump 1 and the gas output by the air pump 2 are initially mixed in the mixer 11. The mixer 11 is designed to break large bubbles in the liquid within the Venturi tube, forming a large number of microbubbles containing air, thereby allowing the ozone after the air is ionized to dissolve rapidly in the liquid.

[0036] Reference Figure 2 and Figure 3As shown, the plasma cavitation assembly 4 includes a housing and a reaction mechanism. The reaction mechanism is located inside the housing, which contains a reaction channel 47. Multiple reaction mechanisms are continuously arranged along the transport path of the reaction channel 47. In this embodiment, the reaction channel 47 extends horizontally. Depending on the arrangement of the plasma cavitation assembly 4, the reaction channel 47 can also extend vertically or obliquely. The reaction mechanism includes a plasma reaction unit 45 and a cavitation unit 46. The plasma reaction unit 45 and the cavitation unit 46 are arranged along the transport path of the reaction channel 47, and the plasma reaction unit 45 is located at the input end of the reaction channel 47. During the flow of the liquid containing bubbles along the reaction channel 47, the plasma reaction unit 45 first ionizes the air bubbles in the liquid, and then the cavitation unit 46 cavitates the liquid. The plasma reaction unit 45 and the cavitation unit 46 are arranged alternately along the transport path of the reaction channel 47. The output end of the feeding component is connected to the input end of the reaction channel 47. Specifically, the output end of the mixing component 11 is connected to the input end of the reaction channel 47, so that the liquid containing bubbles can enter the reaction channel 47.

[0037] The plasma reaction unit 45 includes a first electrode 451 and a second electrode 453. A reaction channel 47 is located between the first electrode 451 and the second electrode 453. The first electrode 451 is a high-voltage electrode, and the second electrode 453 is a grounded electrode. In this embodiment, the first electrode 451 is located above the second electrode 453, that is, the first electrode 451 and the second electrode 453 are arranged vertically. Depending on the extension direction of different reaction channels 47, the first electrode 451 and the second electrode 453 can be arranged in different directions. A first protrusion 452 is provided on the side of the first electrode 451 near the second electrode 453. The sidewall of the first protrusion 452 is arc-shaped. A groove 454 corresponding to the position of the first protrusion 452 is provided on the side of the second electrode 453 near the first electrode 451. The arrangement of the first protrusion 452 and the groove 454 extends the flow path of the liquid between the first electrode 451 and the second electrode 453. At the same time, the distance between the first electrode 451 and the second electrode 453 and the distance between the first protrusion 452 and the groove 454 remain equal along the transport path, that is, a constant distance is maintained between the first electrode 451 and the second electrode 453. In some existing micro-discharge devices, the distance between the positive and negative electrodes varies along the flow direction, resulting in an uneven electric field in the flow direction and difficulty in maintaining a consistent voltage. This causes fluctuations in the ozone generation rate and active material, further affecting the cleaning efficiency and process control to avoid uneven discharge caused by changes in electrode spacing. The plasma reaction unit 45 of this application, through a constant distance between the first electrode 451 and the second electrode 453, enables the liquid to form an equivalently extended flow path within the discharge region, thereby extending the residence time of the liquid in the effective discharge region and improving the ozone generation efficiency. In this embodiment, the first electrode 451 is provided with two first protrusions 452, and the second electrode 453 is provided with two grooves 454. Depending on the lengths of the first electrode 451 and the second electrode 453, different numbers of first protrusions 452 and grooves 454 can be provided.

[0038] The plasma reaction unit 45 also includes a first dielectric barrier layer 455 and a second dielectric barrier layer 456, both of which are made of quartz glass or materials with a high dielectric constant. The first dielectric barrier layer 455 is located on the side of the first electrode 451 closest to the second electrode 453, and the second dielectric barrier layer 456 is located on the side of the second electrode 453 closest to the first electrode 451, thus placing the first dielectric barrier layer 455 and the second dielectric barrier layer 456 between the first electrode 451 and the second electrode 453, forming a dielectric barrier discharge structure. The first electrode 451 is connected to a nanosecond pulse high-voltage power supply via a wire. Under the action of the nanosecond pulse voltage, the plasma reaction unit 45 generates micro-discharge plasma in the liquid containing bubbles, which acts on the bubble-containing liquid through the dielectric barrier layer, thereby generating active substances such as ozone and hydroxyl radicals.

[0039] The cavitation unit 46 includes a first cavitation element 461 and a second cavitation element 462. The cavitation element can be regarded as a cavitation plate. The reaction channel 47 is located between the first cavitation element 461 and the second cavitation element 462. In this embodiment, the first cavitation element 461 is located above the second cavitation element 462, that is, the first cavitation element 461 and the second cavitation element 462 are arranged in a vertical direction. Depending on the different extension directions of the reaction channels 47, the first cavitation element 461 and the second cavitation element 462 can be arranged in different directions. Both the first cavitation element 461 and the second cavitation element 462 are provided with a second protrusion 463 extending into the reaction channel 47. The thickness of the second protrusion 463 gradually decreases towards both ends of the cavitation element, making the sidewall of the second protrusion 463 arc-shaped. This causes the width of the reaction channel 47 between the first cavitation element 461 and the second cavitation element 462 to first gradually decrease and then gradually increase along the liquid flow direction. When the liquid containing bubbles flows between the first cavitation element 461 and the second cavitation element 462, the change in the cross-sectional area of ​​the flow channel causes a rapid change in liquid pressure, inducing a cavitation effect within the cavitation unit 46. Under the action of pressure, a large number of cavitation bubbles are formed in the liquid. By setting the first cavitation element 461 and the second cavitation element 462, the ozone generation and dissolution efficiency can be improved, and efficient and controllable ozone cavitation mass transfer can be achieved in a limited space, thereby obtaining a high-concentration and highly active ozone liquid.

[0040] Preferably, the housing contains multiple parallel reaction channels 47, and the reaction mechanisms are arranged in a matrix array within the housing. The plasma cavitation component 4 has a cubic or cuboid structure, thereby further improving the ozone generation and dissolution efficiency. Specifically, the top of the housing cavity is alternately provided with a first electrode 451 and a first cavitation element 461 along the liquid flow direction, and the bottom of the housing cavity is alternately provided with a second electrode 453 and a second cavitation element 462 along the liquid flow direction. This allows the liquid containing bubbles to undergo the interaction of plasma discharge and cavitation within the reaction channels 47, enhancing the ozone generation efficiency and its dissolution efficiency in the liquid. In the plasma reaction unit 45, which houses the first electrode 451 at the top of the housing cavity and the second electrode 453 at the bottom, the first electrode 451 and the second electrode 453 are integrally formed. In the cavitation unit 46, which houses the first cavitation element 461 at the top of the housing cavity and the second cavitation element 462 at the bottom, the first cavitation element 461 and the second cavitation element 462 are integrally formed. The reaction channel 47 is located on both sides of the plasma reaction unit 45 and the cavitation unit 46, thereby making the overall integration of the plasma cavitation component 4 higher and the volume smaller, reducing equipment maintenance costs, which is conducive to the compact integration of the wafer cleaning production line. Moreover, the plasma reaction unit 45 ionizes air bubbles in the liquid and cavitates the liquid more fully.

[0041] Reference Figure 2 and Figure 4As shown, the semiconductor wafer cleaning apparatus also includes an impeller 3, which is located inside the housing and rotatably connected to the side wall of the housing. The impeller 3 has an output port 32 facing the input end of the reaction channel 47. Specifically, the housing includes a first housing 41 and a second housing 42. Both the first housing 41 and the second housing 42 have connecting portions protruding from the side wall. The connecting portions of the first housing 41 and the second housing 42 are connected by bolts 44, thereby connecting the first housing 41 and the second housing 42. To improve the sealing between the first housing 41 and the second housing 42, a sealing element 43 is provided between them. The reaction mechanism is located inside the first housing 41, and the second housing 42 has a housing space. The impeller 3 is located inside the housing space and rotatably connected to the interior of the second housing 42. The output end of the feeding assembly and the input end of the reaction channel 47 are both connected to the housing space. Specifically, the bottom of the second housing 42 has an inlet 421 corresponding to the position of the side wall of the impeller 3, and the output end of the mixing component 11 of the feeding assembly is connected to the inlet 421.

[0042] The impeller 3 includes a connecting shaft 34. The semiconductor wafer cleaning apparatus also includes a first driving component (not shown) for driving the impeller 3 to rotate. The first driving component can be considered as a motor. The output end of the first driving component is connected to the connecting shaft 34, thereby enabling the first driving component to drive the impeller 3 to rotate. The impeller 3 also includes a protective shell 31 and blades 33 arranged equidistantly in the circumferential direction between the protective shells 31. The connecting shaft 34 is connected to one of the protective shells 31. A feed channel is formed between two adjacent blades 33. The end of the feed channel away from the connecting shaft 34 forms the inlet 36 of the impeller 3. The width of the feed channel gradually decreases towards the connecting shaft 34, so that liquid containing air bubbles can enter the feed channel and flow along the feed channel during the rotation of the impeller 3, thereby achieving active suction of liquid through the rotation of the impeller 3. The blades 33 are generally arc-shaped, and the extension direction of the blades 33 is a left-handed structure. The impeller 3 rotates counterclockwise from top to bottom. During the rotation of the impeller 3, the blades 33 shear and entrain the liquid containing air bubbles, further breaking the gas entering the impeller 3 into tiny bubbles and uniformly mixing them with the liquid to form a homogeneous and stable gas-liquid two-phase mixture. A mixing chamber 35, formed by multiple blades 33, is located in the middle of the impeller 3. The opening of the mixing chamber 35 constitutes the output port 32 of the impeller 3. The output port 32 is located in the middle of the protective shell 31, away from the connecting shaft 34. The bottom area of ​​the mixing chamber 35 is larger than the area of ​​the output port 32, causing the diameter of the mixing chamber 35 to gradually decrease towards the output port 32. This allows the liquid to flow towards the middle of the mixing chamber 35 during the rotation of the impeller 3, and then flow out through the output port 32 under pressure. Through the gradual change in the diameter of the mixing chamber 35 and the left-handed rotating blades 33, a stable axial suction and radial absorption effect is formed within the impeller 3 for the liquid containing air bubbles, reducing the gas-liquid separation time and improving the gas-liquid mixing efficiency. By setting the impeller 3, the gas-liquid mixture entering the reaction channel 47 is effectively improved in terms of flow distribution, gas-liquid phase state and stability, thereby improving the uniformity of discharge in the plasma reaction unit 45 and the stability of cavitation reaction, and further enhancing the generation efficiency of ozone and active substances.

[0043] Reference Figure 2 and Figure 5As shown, the plasma cavitation assembly 4 also includes a flow path guiding mechanism 48 located between the impeller 3 and the reaction mechanism. The flow path guiding mechanism 48 includes an elastic element 481 and an abutment element 482 located within the accommodating space. The elastic element 481 can be considered as a spring, and its two ends are respectively connected to the abutment element 482 and the inner wall of the second housing 42. One side of the abutment element 482 abuts against the inner wall of the second housing 42 and can move along the inner wall of the second housing 42. The abutment element 482 is provided with a third protrusion, and the side of the impeller 3 near the reaction mechanism is provided with an annular guide groove 37. Specifically, the protective shell 31 is provided with an annular guide groove 37. The guide groove 37 corresponds to the position of the third protrusion. Pressure is applied to the abutment element 482 by the elastic element 481, causing the third protrusion to extend into the guide groove 37 and slide in connection with the guide groove 37. During the rotation of the impeller 3, pressure is applied to the abutment 482 by the elastic element 481, ensuring that the abutment 482 remains in contact with the protective shell 31 of the impeller 3. The third protrusion extends into the guide groove 37 and fits against the inner wall of the guide groove 37. Simultaneously, the third protrusion slides relative to the guide groove 37, thereby guiding the abutment 482 during the rotation of the impeller 3. The abutment 482 can move relative to the guide groove 37 as its contour changes. During the movement of the abutment 482, the elastic element 481 deforms, thus not interfering with the normal rotation of the impeller 3. In this embodiment, plasma cavitation components 4 are provided at both the top and bottom of the accommodating space. Through the cooperation of the flow path guiding mechanism 48 and the impeller 3, a continuous flow guiding area is formed between the impeller 3 and the inner wall of the second housing 42. Without sealing or restricting the impeller 3, the liquid flow around the impeller 3 and at the feed inlet 421 is guided. The liquid is guided into the working area of ​​the impeller 3. After forming a stable flow state under the rotation of the impeller 3, the liquid enters the feed channel through the inlet 36 of the impeller 3. This helps to improve the uniformity and stability of the gas-liquid mixing state in the reaction channel 47, reduce the impact of flow state fluctuations in the reaction channel 47 on the subsequent reaction process, improve the generation efficiency of ozone and active substances, and avoid the reduction of ozone generation efficiency caused by the liquid entering the reaction channel 47 through the gap between the impeller 3 and the inner wall of the second housing 42 when the liquid is not working, the impeller 3 is at a low speed, or there are instantaneous pressure fluctuations.

[0044] Reference Figures 6 to 8As shown, the spray assembly 5 is used to clean the wafer, and the input end of the spray assembly 5 is connected to the output end of the reaction channel 47. Specifically, the spray assembly 5 includes multiple spray elements 52. The first housing 41 has a discharge port 411 on the side near the spray assembly 5, which is connected to the output end of the reaction channel 47. Each spray element 52 is connected to the discharge port 411 through a pipe, so that the ozone liquid output from the reaction channel 47 can flow to the spray element 52 through the pipe. The bottom of the spray element 52 is connected to a first support 51, which is used to abut against the outside to keep the spray element 52 stable.

[0045] The semiconductor wafer cleaning apparatus also includes a carrier assembly 6, which comprises a tray 62 and clamping members 64. The tray 62 includes a carrying space, and the bottom of the carrying space has multiple drainage holes 66. The clamping members 64 are hinged to the edge of the tray 62, and the spraying end of the spraying member 52 faces the carrying space. Specifically, the radial cross-section of the tray 62 is circular and has a slot 63. The carrying space is located within the slot 63, and a drain groove 65 is located at the bottom center of the slot 63. The drainage holes 66 are located at the bottom of the drain groove 65. A second support 61 is connected to the bottom of the tray 62. The second support 61 is used to abut against the outside, thereby keeping the tray 62 stable. The three clamping members 64 are arranged at equal angles along the circumference of the tray 62. The tray 62 is also connected to a second drive unit (not shown), which can be considered a motor. The clamping member 64 is connected to a rotating shaft, which is hinged to the edge of the tray 62. The output end of the second drive unit is connected to the rotating shaft, enabling the second drive unit to drive the clamping member 64 to rotate. When the wafer to be cleaned is located in the slot 63, the second drive unit can drive the clamping member 64 to rotate until it abuts against the edge of the wafer, thus keeping the wafer stable within the slot 63 and preventing displacement during cleaning, while also avoiding obstruction of the main cleaning area of ​​the wafer. The cleaning liquid can be discharged to the outside through the drain hole 66. To avoid damage to the wafer, the clamping member 64 is made of a flexible material. In this embodiment, the spray assembly 5 includes three spray elements 52. The spray elements 52 can spray ozone liquid onto the surface of the wafer. The three spray elements 52 are arranged at equal angles along the circumference of the tray 62, that is, the included angle between the center lines of two adjacent spray elements 52 is 120°. The spraying end of the spray element 52 faces the carrying space. By setting multiple spray elements 52, the spray elements 52 can clean the wafer from multiple angles, resulting in a cleaner cleaning.

[0046] The semiconductor wafer cleaning apparatus also includes a flipping assembly 8, whose actuating end can extend into the carrying space. Specifically, the flipping assembly 8 can be regarded as a robotic arm with a clamping mechanism. The side wall of the slot 63 on the tray 62 has an opening, and the edge of the wafer is located at the opening. This allows the robotic arm to drive the clamping mechanism to clamp the edge of the wafer and flip it 180°, so that the front and back sides of the wafer can be cleaned sequentially, thereby effectively cleaning both sides of the wafer and ensuring that the cleaning degree of the front and back sides is consistent. Before the wafer is flipped, the second driving member drives the clamping member 64 to rotate, so that the clamping member 64 is in an open state, so that the clamping mechanism can clamp the wafer and drive the wafer out of the slot 63. In another embodiment, the flipping component 8 can be regarded as a robotic arm with two suction cups. When one suction cup adsorbs the wafer and lifts the wafer, the other suction cup adsorbs the bottom side of the wafer. At this time, the two suction cups are respectively adsorbed on the front and back sides of the wafer. Then the robotic arm drives the wafer to flip 180°. Then the suction cup close to the tray 62 detaches from the wafer and finally places the wafer on the tray 62.

[0047] In operation, air pump 2 first introduces air into reaction channel 47, filling it with air. Then, plasma reaction unit 45 ionizes the air, forming an active substance containing ozone within reaction channel 47. This prevents untreated air from being sprayed out by spray unit 52 and affecting the clean environment of the wafer surface. Then, liquid pump 1 and air pump 2 output liquid and gas respectively. The liquid and gas are initially mixed in mixing unit 11 to form a liquid containing bubbles, which flows to impeller 3. In impeller 3, the gas is further cut into tiny bubbles and uniformly mixed in the liquid, forming a uniform and stable gas-liquid two-phase mixture. Then, the gas-liquid two-phase mixture enters reaction channel 47 and, through the interaction of plasma discharge and cavitation, gradually forms a high-concentration ozone liquid. The ozone liquid passes through a pipe and is sprayed out by spray unit 52 onto the wafer 7 to be cleaned on tray 62. After one side of the wafer is cleaned, the wafer is flipped 180° by flipping component 8 to clean the other side of the wafer until both sides of the wafer are cleaned.

[0048] Reference Figure 9 As shown, the present invention also provides a wafer cleaning method, which uses the above-mentioned semiconductor wafer cleaning apparatus to clean the wafer, including the following steps: Step S1: The feeding assembly introduces air into the reaction channel 47, and the air fills the reaction channel 47; Step S2: The plasma reaction unit 45 ionizes the air, and an active substance containing ozone is formed in the reaction channel 47; Step S3: The feeding assembly introduces a liquid containing bubbles into the reaction channel 47, and the liquid flows along the reaction channel 47. The plasma reaction unit 45 ionizes the bubbles in the liquid, and the cavitation unit 46 cavitates the liquid, generating an active substance containing ozone in the liquid; Step S4: The liquid containing the active substance is sprayed through the spray assembly 5 to clean the wafer.

[0049] Before step S1, a loading step is included, where the wafer 7 to be cleaned is moved into the slot 63, and the clamping member 64 clamps the wafer 7 to be cleaned. Between step S3 and step S2, a preliminary mixing step is included, where the liquid pump 1 and the air pump 2 output liquid and gas respectively. The liquid and gas are initially mixed in the mixing member 11 to form a liquid containing bubbles. After the preliminary mixing step, an impeller 3 mixing step is included, where the liquid containing bubbles flows to the impeller 3. In the impeller 3, the gas is further cut into tiny bubbles and uniformly mixed in the liquid to form a uniform and stable gas-liquid two-phase mixture. After step S4, a flipping step is included, where the flipping component 8 flips the wafer 180°, and the spraying component 5 continues to clean the wafer. Before the flipping step, a wafer inspection step is included, which inspects the surface of the wafer after cleaning. If the inspection result meets the expected standard, the flipping component 8 flips the wafer 180°. After the flipping step, a second wafer inspection step is included, which inspects the surface of the wafer after cleaning. If the inspection result meets the expected standard, the wafer cleaning is completed. At this point, particulate contaminants, organic contaminants, and metal ions on the wafer surface have been efficiently and uniformly cleaned and removed.

[0050] This invention discloses a cleaning apparatus and method for semiconductor wafers. Multiple reaction mechanisms are arranged along a transport path of a reaction channel 47. Each reaction mechanism includes a reaction unit 45 and a cavitation unit 46 arranged along the transport path of the reaction channel 47. This allows the liquid containing bubbles within the reaction channel 47 to alternately undergo bubble ionization and liquid cavitation. During continuous flow, the bubble-containing liquid, following a predetermined transport path, alternately experiences bubble ionization and liquid cavitation, forming an ozone generation and dissolution mechanism coupled with the liquid flow process. By alternating bubble ionization and liquid cavitation, ozone can be formed in segments during the liquid flow process. Each time ozone is formed, the cavitation unit 46 accelerates its dissolution, thereby avoiding localized saturation and rapid decay caused by concentrated ozone generation. By alternating between bubble ionization and liquid cavitation, ozone can be segmented and dissolved instantly, thereby reducing the peak instantaneous concentration of ozone in local areas, slowing down the decomposition rate of ozone, and extending the effective existence time of ozone in the liquid. This, in turn, increases the effective existence time of ozone in the liquid, enhances the ozone generation efficiency and the dissolution efficiency in the liquid, and improves the ozone concentration of the liquid sprayed by the spray component 5, thereby improving the cleaning efficiency of the wafer. The plasma cavitation component 4 completes the generation, dissolution, and transport of ozone under controlled flow conditions, so that the generated ozone liquid matches the semiconductor cleaning process in terms of cleanliness, uniformity, and reaction intensity.

[0051] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A cleaning apparatus for semiconductor wafers, characterized in that, Includes feeding components, plasma cavitation components, and spraying components; The plasma cavitation assembly includes a housing and a reaction mechanism. The reaction mechanism is located inside the housing, and a reaction channel is provided inside the housing. Multiple reaction mechanisms are arranged along the transport path of the reaction channel. Each reaction mechanism includes a plasma reaction unit and a cavitation unit, and the plasma reaction unit and the cavitation unit are arranged along the transport path of the reaction channel. The output end of the feeding component is connected to the input end of the reaction channel; The input end of the spray assembly is connected to the output end of the reaction channel.

2. The semiconductor wafer cleaning apparatus according to claim 1, characterized in that: The plasma reaction unit includes a first electrode and a second electrode. The reaction channel is located between the first electrode and the second electrode. The first electrode has a first protrusion on the side near the second electrode. The sidewall of the first protrusion is arc-shaped. The second electrode has a groove on the side near the first electrode that corresponds to the position of the first protrusion. The distance between the first electrode and the second electrode and the distance between the first protrusion and the groove are kept equal along the transport path.

3. The semiconductor wafer cleaning apparatus according to claim 2, characterized in that: The plasma reaction unit further includes a first dielectric barrier layer and a second dielectric barrier layer. The first dielectric barrier layer is located on the side of the first electrode close to the second electrode, and the second dielectric barrier layer is located on the side of the second electrode close to the first electrode.

4. The semiconductor wafer cleaning apparatus according to claim 1, characterized in that: The cavitation unit includes a first cavitation element and a second cavitation element, and the reaction channel is located between the first cavitation element and the second cavitation element. Both the first cavitation element and the second cavitation element are provided with a second protrusion extending into the reaction channel.

5. The semiconductor wafer cleaning apparatus according to claim 1, characterized in that: It also includes an impeller. The housing includes a first housing and a second housing. The first housing is connected to the second housing. The reaction mechanism is located inside the first housing. The second housing has a housing space. The impeller is located inside the housing space. The impeller is rotatably connected to the side wall of the second housing. The impeller has an output port. The output port faces the input end of the reaction channel. The output end of the feeding assembly and the input end of the reaction channel are both connected to the housing space.

6. The semiconductor wafer cleaning apparatus according to claim 5, characterized in that: The plasma cavitation assembly further includes a flow path guiding mechanism located between the impeller and the reaction mechanism. The flow path guiding mechanism includes an elastic element and an abutment element. The two ends of the elastic element are respectively connected to the abutment element and the inner wall of the second housing. The abutment element is provided with a third protrusion. The side of the impeller near the reaction mechanism is provided with an annular guide groove. The third protrusion is slidably connected to the guide groove.

7. The semiconductor wafer cleaning apparatus according to claim 1, characterized in that: The feeding assembly includes a liquid pump, an air pump, and a mixing component. The output ends of the liquid pump and the air pump are both connected to the mixing component, and the output end of the mixing component is connected to the input end of the reaction channel.

8. The semiconductor wafer cleaning apparatus according to claim 1, characterized in that: It also includes a support assembly, which includes a tray and a clamping member. The tray includes a support space with multiple drainage holes at the bottom. The clamping member is hinged to the edge of the tray. The spray assembly includes multiple spray elements with the spraying ends of the spray elements facing the support space.

9. The semiconductor wafer cleaning apparatus according to claim 8, characterized in that: It also includes a flipping component, the execution end of which can extend into the carrying space.

10. A wafer cleaning method, characterized in that, The semiconductor wafer cleaning apparatus according to any one of claims 1-9 is used to clean the wafer, comprising the following steps: Step S1: The feeding assembly introduces air into the reaction channel, and the air fills the reaction channel; Step S2: The plasma reaction unit ionizes the air, and an active substance containing ozone is formed in the reaction channel; Step S3: The feeding assembly introduces a liquid containing bubbles into the reaction channel. The liquid flows along the reaction channel. The plasma reaction unit ionizes the bubbles in the liquid, and the cavitation unit cavitates the liquid, generating active substances containing ozone in the liquid. Step S4: The liquid containing active substances cleans the wafer through the spray assembly.

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