Wafer cleaning apparatus, cleaning method, and processing equipment

Abstract

This invention discloses a wafer cleaning apparatus, cleaning method, and processing equipment. The wafer cleaning apparatus includes: a chamber and a chuck, nozzles, an upper baffle ring, and a lower baffle ring disposed within the chamber. An air supply unit is provided at the top of the chamber. The chuck is used to horizontally clamp and rotate the wafer. The nozzles are used to spray cleaning fluid onto the front and / or back of the wafer. The upper baffle ring surrounds the chuck and includes an upper baffle edge, a lower baffle edge, an external exhaust port, and an external liquid drain port. The outward end of the upper baffle edge extends downward and merges with the outward end of the lower baffle edge to form a semi-closed cavity. The external exhaust port and the external liquid drain port penetrate the upper baffle edge. The opening of the cavity faces inward and is aligned with the wafer and the chuck during wafer cleaning. The lower baffle ring surrounds the back of the chuck and is disposed inside the upper baffle ring, including an internal exhaust port and an internal liquid drain port. Gas during wafer cleaning is discharged through the external exhaust port and the internal exhaust port, and liquid is discharged through the external liquid drain port and the internal liquid drain port, so that no dead zone of airflow field is formed in the chamber.

Description

Technical Field

[0001] This invention belongs to the field of chemical mechanical polishing technology and is used for processing semiconductor chips. Specifically, it relates to a wafer cleaning apparatus, cleaning method, and processing equipment. Background Technology

[0002] In the wet cleaning process of semiconductor wafers, the cleanliness of the microenvironment within the cleaning chamber is crucial. Waste gases and liquids generated during the process need to be discharged promptly and evenly. Uneven ventilation can easily create dead zones or flow pools within the chamber, causing airborne contaminants to remain or diffuse, potentially depositing on the wafer or chamber components, resulting in secondary wafer contamination and severely impacting product yield.

[0003] The existing cleaning chamber uses a single bottom-connected structure for exhaust. This structure has the following technical drawbacks: First, the single duct layout makes it difficult to ensure the uniformity of the exhaust flow field throughout the process area, easily forming dead zones or flow pooling in local areas. This causes airborne pollutants (such as waste gas, liquid, and solid particles generated during the cleaning process) to remain or diffuse, eventually depositing on the wafer surface and causing secondary wafer contamination. Second, with bottom exhaust, liquid is easily drawn back into the exhaust duct under gravity or negative pressure when collecting gas, causing contamination at the plant level. In addition, existing collection rings are usually single-function and cannot meet the needs of various cleaning fluid cleaning processes. Furthermore, the lack of effective cleaning of the chuck and collection ring outside of the process further increases the risk of secondary contamination of the microenvironment.

[0004] Therefore, there is an urgent need for a wafer cleaning device that can achieve uniform distribution of the flow field in the chamber, eliminate dead zones in the flow field, and effectively separate gas and liquid through structural layout optimization. Summary of the Invention

[0005] In view of this, the present invention provides a wafer cleaning apparatus, cleaning method and processing equipment, thereby solving or at least alleviating one or more of the above-mentioned problems and other problems existing in the prior art.

[0006] In a first aspect, the present invention provides a wafer cleaning apparatus, comprising: a chamber and a chuck, a nozzle, an upper baffle ring and a lower baffle ring disposed within the chamber, wherein an air supply unit is provided at the top of the chamber;

[0007] The chuck is used to horizontally clamp and rotate the wafer;

[0008] The nozzle is used to spray cleaning fluid onto the front and / or back of the wafer;

[0009] The upper baffle ring surrounds the chuck and includes an upper baffle edge, a lower baffle edge, an external vent, and an external drain. The outward end of the upper baffle edge extends downward and merges with the outward end of the lower baffle edge to form a semi-closed cavity. The external vent and external drain penetrate the upper baffle edge, and the opening of the cavity faces inward, aligning the wafer and the chuck during wafer cleaning.

[0010] The lower retaining ring surrounds the back of the chuck and is located inside the upper retaining ring, including an internal vent and an internal drain port;

[0011] Gases used for cleaning wafers are discharged through external and internal exhaust ports, while liquids are discharged through external and internal drain ports, preventing the formation of dead zones in the airflow field within the chamber.

[0012] Optionally, multiple external exhaust ports, external liquid drain ports, internal exhaust ports, and internal liquid drain ports are provided, and the multiple external exhaust ports and multiple internal exhaust ports are staggered in the circumferential direction;

[0013] The external exhaust port vents air upwards, the external liquid discharge port discharges liquid outwards, and the external exhaust port is higher than the external liquid discharge port;

[0014] The internal exhaust port exhausts air inward, the internal liquid drain port drains liquid downward, the internal exhaust port is higher than the internal liquid drain port, and the internal exhaust port is located inside the internal liquid drain port.

[0015] Optionally, each of the external exhaust ports is connected to a vertically arranged L-shaped first row of air ducts, so that the gas is discharged upward and outward from the first row of air ducts, and multiple first row of air ducts are evenly distributed circumferentially on the outer side of the upper baffle.

[0016] Each of the internal exhaust ports is connected to a vertically arranged L-shaped second-row air duct, allowing the gas to be discharged inward and downward through the second-row air duct.

[0017] Optionally, the upper stop edge includes a first horizontal portion and a first vertical portion, and the lower stop edge includes a second horizontal portion opposite to the first horizontal portion, wherein the first horizontal portion and the second horizontal portion are connected by the first vertical portion;

[0018] The external exhaust port is located in the first horizontal section;

[0019] The external drain outlet is located in the first vertical section.

[0020] Optionally, it also includes at least two air duct manifolds disposed in the chamber and connected to the outside of the chamber, each air duct manifold being used to combine the outlet gases of at least two first exhaust ducts and lead them out of the chamber.

[0021] The outlet of the air duct manifold is connected to an air outlet adjustment device, which is used to open or close the corresponding outlet of the air duct manifold.

[0022] Optionally, the nozzle includes a front nozzle and a back spray assembly;

[0023] The front nozzle has multiple nozzles connected to different liquid inlets for spraying different types of cleaning solutions onto the front side of the wafer.

[0024] The back spray assembly passes through the center of the chuck and forms a mating gap for spraying cleaning fluid to clean the back side of the wafer.

[0025] Optionally, it also includes a power assembly located below the chuck. The power assembly includes a hollow rotating shaft that can rotate around its own axis to drive the chuck to rotate. The back spray assembly is disposed inside the rotating shaft and forms a mating gap.

[0026] The lower retaining ring is sleeved on the outside of the power assembly and includes an outer vertical part, an inner vertical part and a horizontal connecting part that are arranged opposite to each other. The outer vertical part is located outside the inner vertical part, the inner exhaust port is located in the inner vertical part and the inner drain port is located in the horizontal connecting part.

[0027] Optionally, the upper retaining ring is connected to a lifting device for pushing the upper retaining ring to move up and down relative to the chuck;

[0028] The inward end of the lower stop bends downward to form a mating part, which is located inside the outer upright part and a mating gap is formed between the two.

[0029] A second aspect of the present invention provides a wafer cleaning method using a wafer cleaning apparatus as described in the first aspect, comprising:

[0030] The air outlet regulating device is controlled to open the outlet of the air duct manifold corresponding to the first cleaning liquid;

[0031] Spray the first cleaning solution onto the wafer surface;

[0032] Stop spraying the first cleaning solution onto the wafer surface;

[0033] The air outlet regulating device is controlled to close the outlet of the air duct manifold corresponding to the first cleaning liquid;

[0034] The air outlet regulating device is controlled to open the outlet of the air duct manifold corresponding to the second cleaning fluid;

[0035] A second cleaning solution is sprayed onto the wafer surface.

[0036] A third aspect of the present invention provides a wafer processing apparatus, including a wafer cleaning apparatus as described in the first aspect, the wafer cleaning apparatus being used to clean wafers.

[0037] The beneficial effects of this invention include: by optimizing the local and overall structural layout, the uniformity of the exhaust flow field in the process area is improved, dead zones in the flow field are eliminated, and pollutants are discharged uniformly and quickly. Furthermore, the gas-liquid separation structure design adopted fundamentally avoids the risk of waste liquid flowing into the exhaust system, thereby effectively improving the stability of the wafer cleaning process and the yield of wafer chips. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0039] Figure 1 This is a schematic diagram of the structure of a wafer cleaning device in the prior art.

[0040] Figure 2 yes Figure 1 Schematic diagram of the exhaust airflow field in area A.

[0041] Figure 3 This is a top view of the chamber of a wafer cleaning apparatus according to an embodiment of the present invention.

[0042] Figure 4 yes Figure 3 A schematic cross-sectional view of the device shown along line XX.

[0043] Figure 5 yes Figure 4 A partial cross-sectional view of the upper and middle retaining ring 41 after enlargement.

[0044] Figure 6 yes Figure 3 A schematic diagram of the structure of the upper and middle retaining ring 41.

[0045] Figure 7 yes Figure 3 The device shown along Figure 4 A schematic diagram of the cross section of the YY line.

[0046] Figure 8 This is a flowchart of a wafer cleaning method according to an embodiment of the present invention.

[0047] Reference numerals: 10-Chuck, 20-Power assembly, 21-Rotating shaft, 22-Drive unit, 23-Connecting sealing structure, 30-Nozzle, 31-Back spray assembly, 32-Front nozzle, Inlet 321, 41-Upper retaining ring, 411-Upper retaining edge, 4111-First horizontal part, 4112-First vertical part, 4113-Second vertical part, 4114-First inclined part, 4115-Third horizontal part, 412-Lower retaining edge, 4121-Second horizontal part, 4122-Third vertical part, 41 23-Second inclined part, 4124-Matching part, 42-Lower retaining ring, 421-Internal exhaust port, 422-Internal drain port, 423-Second row air duct, 424-External upright part, 425-Internal upright part, 426-Horizontal connecting part, 43-Cavity, 431-External exhaust port, 432-External drain port, 433-First row air duct, 50-Cavity, 51-Air supply unit, 52-Bracket, 60-Air duct collecting pipe, 61-Air outlet adjusting device, 70-Back microenvironment cleaning nozzle, wafer cleaning device 100. Detailed Implementation

[0048] To enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art should fall within the protection scope of the present invention.

[0049] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0050] In addition, in the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0051] Figure 1This is a schematic diagram of the structure of a wafer cleaning device in the prior art. As shown in the figure, the wafer cleaning device includes a chamber 50 and a chuck 10, a power unit 20, a nozzle 30 and a retaining ring 40 located in the chamber 50. The top of the chamber 50 is provided with an air supply unit 51 to supply clean air into the chamber during cleaning, and the bottom is provided with an exhaust port and a liquid drain port.

[0052] The chuck 10 is used to horizontally clamp the wafer. The power assembly 20 is located below the chuck 10. The power assembly 20 includes a rotating shaft 21 and a drive unit 22. The rotating shaft 21 is connected to the chuck 10. The drive unit 22 drives the rotating shaft 21 to rotate the chuck 10, thereby causing the wafer to rotate horizontally.

[0053] The nozzle 30 includes a front nozzle (not shown) for spraying cleaning fluid onto the front side of the wafer and a back spray assembly 31 for spraying cleaning fluid onto the back side of the wafer. The rotating shaft 21 is a hollow tube, and the back spray assembly 31 is disposed inside the rotating shaft 21. The upper end of the back spray assembly 31 passes through the chuck 10 to spray cleaning fluid onto the back side of the wafer. With the rotation of the wafer, the cleaning fluid can be made to cover the surface of the wafer through centrifugal motion.

[0054] A connecting sealing structure 23 for the power assembly 20 is also provided between the chuck 10 and the power assembly 20 to prevent cleaning fluid from entering the interior of the power assembly 20. It can be seen that the rotating shaft 21 of the chuck 10 and the power assembly 20 is the rotating part, and the back spray assembly 31 and the connecting sealing structure 23 are the fixed parts, with a fitting clearance formed between the rotating part and the fixed part.

[0055] A retaining ring 40 is arranged around the chuck 10, dividing the space within the chamber 50 axially into an outer retaining ring and an inner retaining ring. This serves to block the cleaning fluid ejected with the wafer and chuck during cleaning and to guide the polishing fluid downwards to the bottom of the retaining ring 40. To facilitate wafer exchange and chuck maintenance, the retaining ring 40 includes an upper retaining ring 41 and a lower retaining ring 42. The lower retaining ring 42 is fixed, while the upper retaining ring 41 can move up and down, forming a fitting gap with the lower retaining ring 42. During cleaning operations, the upper retaining ring 41 rises above the wafer, and during non-cleaning operations, the upper retaining ring 41 descends to a position no higher than the chuck 10.

[0056] The lower retaining ring 42 is connected inward to the connecting sealing structure 23, and its exterior is the bottom plate of the chamber 50. Using the lower retaining ring 42 as a boundary, the exhaust port and drain port include an external exhaust port 431 and an external drain port 432 outside the retaining ring 42, and an internal exhaust port 421 and an internal drain port 422 inside the retaining ring 42. At least one internal exhaust port 421 and one internal drain port 422 (not shown) are located on the bottom surface of the lower retaining ring 42, and at least one external exhaust port 431 and one external drain port 432 (not shown) are located on the bottom plate of the chamber 50. The drain port is located on the bottom surface of the lower retaining ring 42 or at the lowest point of the bottom plate of the chamber 50, and its rear end is connected to the liquid-gas treatment device at the plant end; the exhaust port is cylindrical, and its rear end is connected to the waste gas treatment device at the plant end. The exhaust port protrudes from the corresponding bottom surface to prevent undischarged waste liquid from flowing into the exhaust port due to the height difference with the drain port.

[0057] During cleaning operations, the ideal gas flow direction is as follows: Figure 1 As indicated by multiple arrows, the air supply unit continuously delivers clean air downwards, flowing through the area below the lower part of the baffle ring 42 around the chuck 10 and around the baffle ring 40 into the lower part of the chamber 50, and finally exiting through the exhaust port. However, the high-speed rotation of the chuck 10 and the wafer creates local pressure differences, causing turbulence. In addition, the space below the exhaust port can easily cause local backflow, making it difficult to ensure the uniformity of the exhaust airflow field within the chamber.

[0058] Figure 2 yes Figure 1 The diagram shows the exhaust airflow field in area A. As illustrated, the exhaust airflow field not only creates a dead zone in area C, easily leading to the accumulation, deposition, and even crystallization of contaminants, posing safety and quality risks to equipment and wafers, but also causes reverse airflow in area B, directly increasing the risk of secondary contamination of wafers and severely impacting wafer chip yield. Furthermore, due to the turbulent gas flow, contaminants may also flow into the exhaust channel with liquids, potentially leading to long-term plant safety risks.

[0059] To address this technical problem, this application provides a wafer cleaning apparatus 100. For example... Figure 3-6 As shown, the wafer cleaning apparatus includes a chamber 50 and a chuck 10, a nozzle 30, an upper baffle ring 41 and a lower baffle ring 42 located in the chamber 50. An air supply unit 51 is provided on the top of the chamber 50 to supply clean air into the chamber during cleaning.

[0060] The chuck 10 is used to horizontally clamp and rotate the wafer, and the nozzle 30 is used to spray cleaning fluid onto the front and / or back of the wafer. Optionally, the nozzle 30 includes a front nozzle 32 for spraying cleaning fluid onto the front of the wafer and a back spray assembly 31 for spraying cleaning fluid onto the back of the wafer, so as to achieve simultaneous cleaning of the front and back of the wafer.

[0061] The wafer cleaning apparatus 100 also includes a power assembly 20 located below the chuck 10. The power assembly 20 includes a rotating shaft 21 and a drive unit 22. The rotating shaft 21 is connected to the chuck 10, and the drive unit 22 drives the rotating shaft 21 to rotate the chuck 10, thereby causing the wafer to rotate horizontally. The rotating shaft 21 is a hollow tube, and a back spray assembly 31 is disposed inside the rotating shaft 21. The upper end of the back spray assembly 31 passes through the chuck 10 to spray cleaning fluid onto the back side of the wafer.

[0062] The upper retaining ring 41 surrounds the chuck 10, as shown. Figure 4 As shown, the upper baffle ring 41 includes an upper baffle 411, a lower baffle 412, an external vent 431, and an external drain 432. The outward end of the upper baffle 411 extends downward and merges with the outward end of the lower baffle 412 to form a semi-enclosed cavity 43, with the outward end being the end furthest from the chuck 10. The opening of the cavity 43 faces inward and is aligned with the wafer and chuck during wafer cleaning. That is, during wafer cleaning, the inward end of the upper baffle 411 is higher than the upper surface of the wafer, and the inward end of the lower baffle 412 is not higher than the chuck 10, so that as much gas and waste liquid thrown out by the chuck 10 and the wafer as possible can enter the cavity 43 and be confined within the cavity 43.

[0063] The lower retaining ring 42 is located below the chuck 10, surrounding the back of the chuck 10 (that is, fitted onto the outside of the power assembly 20) and positioned inside the upper retaining ring 41. This allows gas and a small amount of waste liquid passing through the gap between the chuck 10 and the upper retaining ring 41 to enter the area surrounded by the chuck, the upper retaining ring 41, and the lower retaining ring 42. The lower retaining ring 42 is fixedly mounted on the bottom plate of the chamber 50 by a bracket 52. The lower retaining ring 42 includes an internal vent 421 and an internal drain 422.

[0064] External exhaust port 431 and external liquid drain port 432 penetrate the upper baffle 411 to allow gas and liquid in cavity 43 to be discharged; internal exhaust port 421 and internal liquid drain port 422 penetrate the main body of lower baffle ring 42. Gas during wafer cleaning is discharged through external exhaust port 431 and internal exhaust port 421, and liquid is discharged through external liquid drain port 432 and internal liquid drain port 422. Since the gas mainly passes through cavity 43 and is discharged through external exhaust port 431, the guiding and restricting effect of cavity 43 on the gas ensures that the gas flow direction in cavity 43 is basically consistent, while the amount of gas entering the area of ​​lower baffle ring 42 is significantly reduced. Therefore, even if there is a local pressure difference, the flow field uniformity can be guaranteed, and the airflow dead zone cannot be formed in the cavity.

[0065] Optionally, multiple external vent ports 431, external liquid drain ports 432, internal vent ports 421, and internal liquid drain ports 422 are provided. The multiple external vent ports 431 and multiple internal vent ports 421 are staggered circumferentially, preferably at an angle greater than or equal to 5°, to improve gas-liquid separation capability. External vent ports 431 vent upwards (facing the front of the chuck), and external liquid drain ports 432 drain outwards (facing away from the center of the chuck), with external vent ports 431 higher than external liquid drain ports 432. Internal vent ports 421 vent inwards (facing towards the center of the chuck), and internal liquid drain ports 422 drain downwards (facing the back of the chuck), with internal vent ports 421 higher than internal liquid drain ports 422, and internal vent ports 421 located inside internal liquid drain ports 422. By defining the direction of venting, the gas flow direction can be made to tend towards... Figure 4 The direction indicated by the middle arrow further reduces turbulence, thereby improving the uniformity of the gas flow field.

[0066] Optionally, each external exhaust port 431 is connected to a vertically arranged L-shaped first row air duct 433, so that the gas is discharged from the bottom up and then outward from the first row air duct 433. Multiple first row air ducts 433 are evenly distributed around the outer side of the upper baffle 411.

[0067] Optionally, each internal exhaust port 421 is connected to a vertically arranged L-shaped second row air duct 423, so that the gas is discharged inward and downward through the second row air duct. The lower end of the second row air duct 423 extends out of the bottom of the lower baffle ring 42, and multiple second row air ducts 423 are evenly distributed circumferentially.

[0068] Optional, such as Figure 4-5 As shown, both the upper baffle 411 and the lower baffle 412 have outward and downward bending structures. The upper baffle 411 includes a first horizontal portion 4111 and a first vertical portion 4112, and the lower baffle 412 includes a second horizontal portion 4121 opposite to the first horizontal portion 4111. The first horizontal portion 4111 and the second horizontal portion 4121 are connected by the first vertical portion 4112. The external exhaust port 431 is located in the first horizontal portion 4111, and the external liquid discharge port 432 is located in the first vertical portion 4112. This not only provides a stable gas-liquid separation height difference, but also ensures that even if pollutants flow into the exhaust channel with the liquid, the liquid will drip off due to gravity and eventually flow out from the lower external liquid discharge port 432, achieving highly reliable gas-liquid separation.

[0069] Optionally, the upper baffle 411 may also include a second vertical portion 4113, a first inclined portion 4114 and a third horizontal portion 4115 connected in sequence. The second vertical portion 4113 is connected to one inner end of the first horizontal portion 4111, the first inclined portion 4114 is inclined inward, and the inner end of the third horizontal portion 4115 is bent downward to form a blocking structure to prevent gas and liquid backflow.

[0070] The lower baffle 412 also includes a third vertical portion 4122 and a second inclined portion 4123 connected in sequence. The third vertical portion 4122 is connected to one inner end of the second horizontal portion 4121. The second inclined portion 4123 is inclined inward. The end of the second inclined portion 4123 is bent downward to form a mating portion 4124, thereby blocking the gas entering the area of ​​the lower baffle ring 42.

[0071] The first vertical portion 4112 and the second vertical portion 4113 are respectively opposite to the third vertical portion 4122, and the first inclined portion 4114 is opposite to the second inclined portion 4123. The second inclined portion 4123 has a larger inward inclination angle than the first inclined portion 4114, so that the cavity 43 gradually narrows from the opening along the second inclined portion 4123, thereby guiding the gas flow and further preventing the generation of turbulence.

[0072] Optionally, the lower retaining ring 42 is fitted onto the outside of the power assembly 20. The lower retaining ring 42 includes an outer upright portion 424, an inner upright portion 425, and a horizontal connecting portion 426 connecting the two. The outer upright portion 424 is located outside the inner upright portion 425, the inner exhaust port 421 is provided in the inner upright portion 425, and the inner drain port 422 is provided in the horizontal connecting portion 426.

[0073] This combination of lateral exhaust and vertical drainage creates a gas-liquid separation design in the back area, ensuring uniform negative pressure suction in the back area of ​​the chuck, avoiding airflow dead zones, and ensuring that waste liquid generated during back cleaning is not drawn back into the exhaust system.

[0074] Optionally, the second row of air ducts 423 is located inside the inner upright part 425, and the lower end of the second row of air ducts 423 extends from the bottom surface of the lower baffle ring 42.

[0075] Optionally, the upper retaining ring 41 is connected to a lifting device (not shown) for pushing the upper retaining ring 41 to rise and fall relative to the chuck 10. The mating part 4124 is located inside the outer upright part 424 and a mating gap is formed between the two. This mating gap allows the upper retaining ring 41 to move relative to the lower retaining ring 42 during the lifting and falling process, while realizing the physical isolation of the two areas inside and outside the retaining ring.

[0076] Optional, such as Figure 3 As shown, the outlets of all first-row air ducts 433 are not directly connected to external plant facilities, but are connected to the air duct manifold 60 inside the chamber 50. This embodiment has two air duct manifolds 60: one manifold combines the outlet gases from two first-row air ducts 433, and the other manifold combines the outlet gases from three first-row air ducts 433, connecting to the plant facility end via the air outlet regulating device 61. This integrated "multiple inlets, fewer outlets" design improves the flexibility of equipment layout and reduces the number of interfaces to external plant facilities.

[0077] The air outlet regulating device 61 can use control elements such as pneumatic valves and solenoid valves to open or close the outlet of the corresponding air duct manifold 60, thereby regulating the air volume or switching the corresponding exhaust pipe according to different types of cleaning liquids, and preventing cross-contamination of volatile gases from cleaning liquids of different properties.

[0078] Optionally, multiple front nozzles 32 are uniformly fixed along the circumference of the upper baffle ring 41. The multiple liquid inlets corresponding to the multiple front nozzles 32 can be connected to different cleaning liquid sources to spray different types of cleaning liquids (such as deionized water, acidic cleaning liquid, alkaline cleaning liquid, etc.) onto the front side of the wafer at different process stages.

[0079] Optionally, multiple liquid inlets 321 are uniformly fixed along the circumference of the upper baffle ring 41, preferably located in the first vertical portion 4112, with their conduits arranged along the upper baffle edge 411 to connect to multiple front nozzles 32. It is understood that the length of the front nozzle 32 in the accompanying drawings is merely an example, and its front end position should not affect wafer interaction.

[0080] To further ensure cleanliness, a back microenvironment cleaning nozzle 70 is installed on the top of the lower baffle ring 42. During equipment standby or non-main process periods, the back microenvironment cleaning nozzle 70 can be activated to spray and clean the back of the chuck 10, the inner wall of the lower baffle ring 42, the internal exhaust port 421, etc., to prevent contaminants from drying and solidifying at these locations, thus preventing them from becoming secondary sources of pollution.

[0081] like Figure 8 As shown, the method for cleaning using the wafer cleaning apparatus of this embodiment includes the following steps:

[0082] Step S1: Control the air outlet regulating device 61 to open the outlet of the air duct manifold 60 corresponding to the first cleaning liquid (such as acidic cleaning liquid).

[0083] Step S2: Spray a first cleaning solution (such as an acidic cleaning solution) onto the wafer surface to perform the first cleaning step and remove specific contaminants.

[0084] In response to the establishment of a stable negative pressure in the air duct, the first cleaning fluid spraying is started. The gas generated by the evaporation of the first cleaning fluid is promptly drawn away with the clean air supplied by the air supply unit and enters the corresponding exhaust gas treatment device at the plant end through the air duct collection pipe 60 corresponding to the first cleaning fluid, so as to maintain the cleanliness of the process area and the exhaust gas treatment.

[0085] Step S3: Stop spraying the first cleaning solution onto the wafer surface to complete the first cleaning step.

[0086] Step S4: Control the air outlet regulating device 61 to close the outlet of the air duct manifold 60 corresponding to the first cleaning fluid.

[0087] First, stop the supply of the first cleaning fluid, then close the outlet of the air duct manifold 60 corresponding to the first cleaning fluid, so that the amount of the first cleaning fluid remaining in the chamber is as small as possible.

[0088] Step S5: Control the air outlet adjustment device 61 to open the outlet of the air duct manifold 60 corresponding to the second cleaning liquid (such as alkaline cleaning liquid or deionized water).

[0089] Step S6: Spray the second cleaning solution onto the wafer surface to perform the second cleaning step.

[0090] After the duct establishes a stable negative pressure, the second cleaning fluid spraying is started. The gas generated by the evaporation of the second cleaning fluid is promptly drawn away with the clean air supplied by the air supply unit and enters the corresponding exhaust gas treatment device at the plant end through the duct collection pipe 60 corresponding to the second cleaning fluid, maintaining the cleanliness of the process area and exhaust gas treatment.

[0091] Through the above steps, independent exhaust control of the cleaning process with different cleaning solutions is achieved, avoiding the mixing of gases of different properties in the exhaust pipeline, reducing the risk of chemical reaction, improving process safety, and reducing the cumbersome physical separation of mixed gases at the plant end.

[0092] This invention also provides a wafer processing apparatus, including the above-described wafer cleaning device, for horizontally cleaning wafers in a post-wafer processing step.

[0093] Optionally, the wafer processing equipment includes chemical mechanical polishing equipment, wafer thinning equipment, coating equipment, ion implantation equipment, bonding equipment, etc., and the post-wafer processing steps include a cleaning step. The processing equipment may also include wafer transport devices, polishing devices, control devices, etc., forming a complete wafer processing production line.

[0094] A control device for executing the wafer cleaning method of the present invention includes: a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps as described in the embodiments of the wafer cleaning method above.

[0095] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0096] The above embodiments are only used to illustrate the embodiments of the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of the present invention. Therefore, all equivalent technical solutions also fall within the scope of the embodiments of the present invention, and the patent protection scope of the embodiments of the present invention should be defined by the claims.

Claims

1. A wafer cleaning apparatus, characterized in that, include: The chamber and the chuck, nozzle, upper baffle ring and lower baffle ring disposed in the chamber, with an air supply unit at the top of the chamber; The chuck is used to horizontally hold and rotate the wafer; The nozzle is used to spray cleaning fluid onto the front and / or back of the wafer; The upper baffle ring surrounds the chuck and includes an upper baffle edge, a lower baffle edge, an external vent, and an external drain. The outward end of the upper baffle edge extends downward and merges with the outward end of the lower baffle edge to form a semi-closed cavity. The external vent and external drain penetrate the upper baffle edge, and the opening of the cavity faces inward, aligning the wafer and the chuck during wafer cleaning. The lower retaining ring surrounds the back of the chuck and is located inside the upper retaining ring, including an internal vent and an internal drain port; Gases used for cleaning wafers are discharged through external and internal exhaust ports, while liquids are discharged through external and internal drain ports, preventing the formation of dead zones in the airflow field within the chamber.

2. The wafer cleaning apparatus as described in claim 1, characterized in that, Multiple external exhaust ports, multiple external liquid discharge ports, multiple internal exhaust ports, and multiple internal liquid discharge ports are provided, and the multiple external exhaust ports and multiple internal exhaust ports are staggered in the circumferential direction; The external exhaust port vents air upwards, the external liquid discharge port discharges liquid outwards, and the external exhaust port is higher than the external liquid discharge port; The internal exhaust port exhausts air inward, the internal liquid drain port drains liquid downward, the internal exhaust port is higher than the internal liquid drain port, and the internal exhaust port is located inside the internal liquid drain port.

3. The wafer cleaning apparatus as described in claim 2, characterized in that, Each of the external exhaust ports is connected to a vertically arranged L-shaped first row of air ducts, so that the gas is discharged upward and outward into the first row of air ducts. Multiple first row of air ducts are evenly distributed circumferentially on the outer side of the upper baffle. Each of the internal exhaust ports is connected to a vertically arranged L-shaped second exhaust duct, allowing the gas to be discharged inward and downward through the second exhaust duct.

4. The wafer cleaning apparatus as described in claim 3, characterized in that, The upper stop edge includes a first horizontal portion and a first vertical portion, and the lower stop edge includes a second horizontal portion opposite to the first horizontal portion. The first horizontal portion and the second horizontal portion are connected by the first vertical portion. The external exhaust port is located in the first horizontal section; The external drain outlet is located in the first vertical part.

5. The wafer cleaning apparatus as described in claim 4, characterized in that, It also includes at least two air duct manifolds, which are disposed in the chamber and connected to the outside of the chamber. Each air duct manifold is used to combine the outlet gases of at least two first exhaust ducts and lead them out of the chamber. The outlet of the air duct manifold is connected to an air outlet adjustment device, which is used to open or close the corresponding outlet of the air duct manifold.

6. The wafer cleaning apparatus as described in claim 5, characterized in that, The nozzle includes a front nozzle and a back spray assembly; The front nozzle has multiple nozzles connected to different inlets for spraying different types of cleaning solutions onto the front side of the wafer. The back spray assembly passes through the center of the chuck and forms a mating gap for spraying cleaning fluid to clean the back side of the wafer.

7. The wafer cleaning apparatus as described in claim 6, characterized in that, It also includes a power assembly located below the chuck, the power assembly including a hollow rotating shaft that can rotate around its own axis, used to drive the chuck to rotate, and the back spray assembly is disposed inside the rotating shaft and forms a fitting gap; The lower retaining ring is sleeved on the outside of the power assembly and includes an outer vertical part, an inner vertical part and a horizontal connecting part that are arranged opposite to each other. The outer vertical part is located outside the inner vertical part, the inner exhaust port is located in the inner vertical part and the inner drain port is located in the horizontal connecting part.

8. The wafer cleaning apparatus as described in claim 7, characterized in that, The upper retaining ring is connected to a lifting device for pushing the upper retaining ring to move up and down relative to the chuck; The inward end of the lower stop bends downward to form a mating part, which is located inside the outer upright part and a mating gap is formed between the two.

9. A wafer cleaning method, using the wafer cleaning apparatus as described in any one of claims 5-8, characterized in that, include: The air outlet regulating device is controlled to open the outlet of the air duct manifold corresponding to the first cleaning liquid; Spray the first cleaning solution onto the wafer surface; Stop spraying the first cleaning solution onto the wafer surface; The air outlet regulating device is controlled to close the outlet of the air duct manifold corresponding to the first cleaning liquid; The air outlet regulating device is controlled to open the outlet of the air duct manifold corresponding to the second cleaning fluid; A second cleaning solution is sprayed onto the wafer surface.

10. A wafer processing apparatus, characterized in that, Includes a wafer cleaning apparatus as described in any one of claims 1-8, the wafer cleaning apparatus being used for cleaning wafers.

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