Wafer chuck for preventing secondary contamination of liquid

Abstract

This application discloses a wafer chuck for preventing secondary liquid contamination, belonging to the field of semiconductor processing technology. It includes: a chuck base with a circumferentially arranged mounting hole; and a chuck pin movably disposed within the mounting hole, comprising a fixing part and a replacement part that engage vertically. The replacement part includes a wafer holder and a clamping member. The wafer holder and clamping member are integrally formed and can rotate around the axis of the wafer holder. The upper surface of the wafer holder supports the wafer, and the clamping member, after rotating around the axis of the wafer holder, clamps the wafer. The upper end face of the clamping member has several guide grooves, and the upper end face of the wafer holder has several drainage grooves, used to guide liquid splashed during wafer rotation. Through the overall design of the wafer chuck, liquid on the wafer surface can be guided and quickly dispersed, preventing secondary contamination caused by liquid retention or backflow on the wafer surface, thus improving product yield.

Description

Technical Field

[0001] This application relates to a wafer chuck that prevents secondary contamination by liquids, belonging to the field of semiconductor processing technology. Background Technology

[0002] In integrated circuit manufacturing, multiple wet processing steps are involved. Wet processing involves immersing or rinsing the wafer with liquid chemicals such as acids, alkalis, and organic compounds to clean surface particles, remove reactive polymers, and etch surface films. As the requirements for process efficiency have increased, wet processing equipment has gradually shifted from early batch processing to single-wafer processing.

[0003] Because wafers are generally thin and processing often involves the use of acids, alkalis, and organic solvents, the chuck pins used to hold the wafers wear out quickly. Wear reduces the clamping capacity of the chuck pins and poses a risk of wafer scraping. Replacing conventional chuck pins requires downtime and individual disassembly and reassembly, impacting production efficiency. Furthermore, during wafer rotation, several process steps involve spraying liquid onto the wafer's front side for cleaning or rinsing. This liquid is ejected by centrifugal force as the wafer rotates, and is caught by an outer retaining ring to reduce splashing. Existing wafer clamping components contact the side or top of the wafer for clamping, which not only poses a splashing problem due to impacts from ejected liquid, but also leaves liquid residue at the contact points, contaminating the dried areas of the wafer, creating defects, and affecting wafer production quality. Therefore, there is an urgent need to design a wafer clamping device that reduces surface water accumulation and backflow, minimizing secondary contamination of the wafer. Utility Model Content

[0004] To address the aforementioned issues, this application proposes a wafer chuck that prevents secondary liquid contamination. This chuck can guide and rapidly disperse liquids on the wafer surface, preventing secondary contamination caused by liquid retention or backflow on the wafer surface and improving product yield.

[0005] According to one aspect of this application, a wafer chuck for preventing secondary liquid contamination is provided, comprising: A chuck holder, wherein a circular hole is provided in the center of the chuck holder and at least four mounting holes are provided in the circumferential direction; A chuck pin is movably disposed within the mounting hole. The chuck pin includes a fixed part and a replacement part that engage with each other. The replacement part includes a wafer tray and a clamping member. The upper end surface of the clamping member is higher than the upper end surface of the wafer tray. The wafer tray and the clamping member are integrally formed and can rotate around the axis of the wafer tray. The upper surface of the wafer tray is used to support the wafer. The clamping member is used to clamp the wafer after rotating around the axis of the wafer tray. The upper end surface of the clamping member is provided with several guide grooves, and the upper end surface of the wafer tray is provided with several drainage grooves to guide the liquid splashed during the wafer rotation. A drive mechanism for driving the chuck holder to rotate about its axis and for driving the chuck pin to rotate about the axis of the wafer holder.

[0006] Specifically, the chuck base includes an upper layer, a middle metal layer, and a lower layer; the upper layer is an isolation layer made of corrosion-resistant material; the middle metal layer is provided with a transmission mechanism, which can be mechanically connected to the drive mechanism and driven by electricity to achieve transmission, thereby realizing the rotation of the chuck pin; the lower layer is provided with mounting holes for connection with the drive mechanism to realize motion control of the chuck base.

[0007] Optionally, the guide groove starts from the end face of the clamping member near the wafer and ends at the end face of the clamping member away from the wafer; the drainage groove starts from the inner side of the end face of the wafer holder near the wafer and ends at the end face of the clamping member away from the wafer, and the drainage groove does not penetrate the wafer holder.

[0008] Optionally, the depth of the guide groove gradually increases from the end closer to the wafer to the end farther away from the wafer.

[0009] Optionally, the ratio of the minimum width to the maximum width of the guide channel is 0.25 to 0.5.

[0010] Optionally, the flow channel is dumbbell-shaped, and the width of the flow channel first decreases and then increases from the end closer to the wafer to the end farther away from the wafer.

[0011] Optionally, the drainage groove is a wedge-shaped groove with a depth that gradually decreases from the end closer to the wafer to the end farther away from the wafer.

[0012] Optionally, the upper surface of the chuck seat is a conical surface.

[0013] Optionally, the angle between the generatrix of the conical surface and the horizontal plane is 2~5°.

[0014] Optionally, the upper end of the fixing part is provided with a protrusion with a cross-shaped cross section, and the lower end of the replacement part is provided with a groove, the groove matching the shape of the protrusion of the fixing part.

[0015] Optionally, the cross-section of the protrusions in each direction of the fixing part is trapezoidal, and the outer surface of the protrusions in each direction of the fixing part is provided with friction strips.

[0016] The beneficial effects that this application may produce include, but are not limited to: 1. The wafer chuck provided in this application enables rapid dispersion of working fluid on the upper and lower surfaces of the wafer by setting drainage grooves and guide grooves on the wafer holder and clamping components, thereby reducing the risk of secondary contamination of the wafer chuck that may be caused by fluid accumulation or backflow on the upper and lower surfaces of the wafer.

[0017] 2. The wafer chuck provided in this application, by setting the chuck pin as a fixed part and a replacement part, can quickly replace the replacement part when the replacement part is worn to a certain extent without disassembling and replacing the entire chuck pin. This not only improves work efficiency, but also avoids corrosion of the metal middle layer of the chuck seat caused by the disassembly and assembly of the chuck pin, and also saves the material cost of the replacement parts. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a front view schematic diagram of the wafer chuck involved in the embodiments of this application; Figure 2 for Figure 1 Enlarged view of a portion of point A in the middle; Figure 3 This is a top view of the chuck pin involved in an embodiment of this application; Figure 4 This is a top view of the fixing part involved in the embodiment of this application; Figure 5 This is a front view schematic diagram of the fixing part involved in the embodiment of this application; Figure 6 This is a top view schematic diagram of the wafer chuck involved in the embodiments of this application; List of components and reference numerals: 1. Chuck holder; 2. Chuck pin; 3. Fixing part; 4. Replacement part; 5. Wafer holder; 6. Clamping part; 7. Guide groove; 8. Drain groove; 9. Protrusion; 10. Friction strip. Detailed Implementation

[0019] To more clearly illustrate the overall concept of this application, a detailed explanation is provided below with reference to the accompanying drawings.

[0020] To better understand the above-mentioned objectives, features, and advantages of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0021] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0022] Furthermore, it should be understood in the description of this application that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application 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 application.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0025] In this application, unless otherwise expressly specified and limited, the "above" or "below" of the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "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 this application. 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 can be combined in any suitable manner in one or more embodiments or examples.

[0026] The wafer chuck in this application is only used to hold the wafer during wafer cleaning, etching and other processes. Since the wafer needs to be rotated during the above-mentioned cleaning, etching and other processes, the wafer chuck in this application can be connected to an additional drive mechanism, which drives the device to rotate in order to process the wafer.

[0027] refer to Figure 1-6 Embodiments of this application provide a wafer chuck for preventing secondary liquid contamination, comprising: The chuck base 1 has a circular hole in the middle and at least four mounting holes in the circumferential direction; A chuck pin 2 is movably disposed within the mounting hole. The chuck pin 2 includes a fixing part 3 and a replacement part 4 that engage vertically. The replacement part 4 includes a wafer tray 5 and a clamping member 6. The upper end surface of the clamping member 6 is higher than the upper end surface of the wafer tray 5. The wafer tray 5 and the clamping member 6 are integrally formed and can rotate around the axis of the wafer tray 5. The upper surface of the wafer tray 5 is used to support the wafer. After rotating around the axis of the wafer tray 5, the clamping member 6 is used to clamp the wafer. The upper end surface of the clamping member 6 is provided with several guide grooves 7, and the upper end surface of the wafer tray 5 is provided with several drainage grooves 8, for guiding liquid splashed during wafer rotation. A driving mechanism is provided for driving the chuck holder 1 to rotate about its axis and for driving the chuck pin 2 to rotate about the axis of the wafer holder 5.

[0028] The flow channel 7 can quickly guide and disperse the liquid on the upper surface of the wafer during wafer rotation, reducing the accumulation of liquid on the upper surface of the wafer and the backflow after contacting the chuck pin 2, thus avoiding secondary contamination of the upper surface of the wafer by the liquid. The flow channel 8 can guide the liquid overflowing to the lower surface of the wafer, reducing the contamination of the lower surface of the wafer by the liquid. On the other hand, it can also reduce the accumulation of liquid between the wafer and the wafer holder 5, thereby improving the wafer yield.

[0029] In one embodiment, the guide groove 7 starts from the end face of the clamping member 6 near the wafer and ends at the end face of the clamping member 6 away from the wafer; the drainage groove 8 starts from the inner side of the end face of the wafer holder 5 near the wafer and ends at the end face of the clamping member 6 away from the wafer, and the drainage groove 8 does not penetrate the wafer holder 5.

[0030] The guide grooves 7 that pass through both ends of the clamping member 6 can quickly disperse the liquid on the upper surface of the wafer; the non-through guide grooves 8 can prevent the overflowing liquid from being carried into the center direction of the lower surface of the wafer, reducing the risk of contaminating the lower surface of the wafer.

[0031] In one implementation, the depth of the guide groove 7 gradually increases from the end closer to the wafer to the end farther away from the wafer.

[0032] At the same width, the greater the depth, the greater the capacity for liquid flow and the faster the flow rate. However, on the side near the wafer, excessive depth will reduce the contact area between the clamping member 6 and the wafer, increase the pressure on the wafer, and increase the risk of wafer brittleness.

[0033] In one embodiment, the ratio of the minimum width to the maximum width of the guide groove 7 is 0.25 to 0.5.

[0034] A certain width difference can cause the liquid flow velocity to differ at different locations, thereby increasing the guiding velocity.

[0035] In one embodiment, the flow channel 7 is dumbbell-shaped, and the width of the flow channel 7 first decreases and then increases from the end closer to the wafer to the end farther away from the wafer.

[0036] The wider extreme width of the flow channel 7 near the wafer allows more liquid to enter the flow channel 7. As the width gradually decreases, the flow velocity increases, promoting the flow rate. Finally, as the width of the flow channel 7 decreases, the liquid flow velocity in the flow channel 7 slows down, resulting in a smaller distance of liquid splashing during rotation, which reduces the amount of liquid rebounding from the wall and further reduces the possibility of secondary contamination of the wafer by liquid.

[0037] In one embodiment, the drainage groove 8 is a wedge-shaped groove whose depth gradually decreases from the end closer to the wafer to the end farther away from the wafer.

[0038] The depth of the drainage groove 8 is relatively large, which can quickly collect the liquid on the lower surface of the wafer. As its depth gradually decreases, the liquid gradually escapes from the end of the drainage groove 8 away from the wafer, thereby achieving the purpose of guiding the liquid.

[0039] In one embodiment, the upper surface of the chuck seat 1 is a conical surface.

[0040] It facilitates the drainage of cleaning liquid during the wafer cleaning process and prevents liquid accumulation in the chuck holder 1 from contaminating the wafer.

[0041] In one embodiment, the angle between the generatrix of the conical surface and the horizontal plane is 2~5°.

[0042] This angle not only allows the cleaning liquid to drain quickly, but also prevents the chuck pin 2 from becoming less stable or affecting the wafer due to an excessive height difference between the center and the outer periphery of the chuck holder 1.

[0043] In one embodiment, the upper end of the fixing part 3 is provided with a protrusion 9 with a cross-shaped cross section, and the lower end of the replacement part 4 is provided with a groove, the groove being matched with the shape of the protrusion 9 of the fixing part 3.

[0044] The protrusion 9 at the upper end of the fixing part 3 and the groove at the lower end of the replacement part 4 can engage. The cross-shaped protrusion 9 makes the force when the fixing part 3 and the replacement part 4 engage more dispersed, reducing stress concentration and improving the engagement strength. The protrusion 9 is located at the upper end of the fixing part 3. Compared with the groove on the fixing part 3, it can reduce the accumulation of cleaning fluid and etching residue on the fixing part 3 and improve cleaning efficiency.

[0045] In one embodiment, the end cross-section of the protrusion 9 of the fixing part 3 in each direction is trapezoidal, and the outer surface of the end of the protrusion 9 of the fixing part 3 in each direction is provided with friction strips 10.

[0046] It can increase the friction between the fixed part 3 and the replacement part 4, and improve the bonding strength between the two.

[0047] The wafer chuck operates as follows: the wafer is placed on the wafer holder 5 on the chuck pin 2, the drive mechanism drives the chuck pin 2 to rotate around the axis of the wafer holder 5 so that the clamping member 6 holds the wafer, and the drive mechanism drives the chuck base 1 to rotate around its axis, thereby rotating the wafer and performing the rinsing operation.

[0048] During this process, the flow channels 8 and 7 on the chuck pin 2, wafer holder 5, and clamping member 6 allow the liquid on the upper and lower surfaces of the wafer to be quickly guided and dispersed away from the wafer, reducing secondary contamination of the wafer chuck by the liquid flow in the wet wafer process and improving the yield of wafer products.

[0049] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0050] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A wafer chuck for preventing secondary contamination by liquids, characterized in that, include: A chuck holder, wherein a circular hole is provided in the center of the chuck holder and at least four mounting holes are provided in the circumferential direction; A chuck pin is movably disposed within the mounting hole. The chuck pin includes a fixed part and a replacement part that engage with each other. The replacement part includes a wafer tray and a clamping member. The upper end surface of the clamping member is higher than the upper end surface of the wafer tray. The wafer tray and the clamping member are integrally formed and can rotate around the axis of the wafer tray. The upper surface of the wafer tray is used to support the wafer. The clamping member is used to clamp the wafer after rotating around the axis of the wafer tray. The upper end surface of the clamping member is provided with several guide grooves, and the upper end surface of the wafer tray is provided with several drainage grooves to guide the liquid splashed during the wafer rotation. A drive mechanism for driving the chuck holder to rotate about its axis and for driving the chuck pin to rotate about the axis of the wafer holder.

2. The wafer chuck for preventing secondary liquid contamination according to claim 1, characterized in that, The guide groove starts from the end face of the clamping member near the wafer and ends at the end face of the clamping member away from the wafer; the drainage groove starts from the inner side of the end face of the wafer holder near the wafer and ends at the end face of the clamping member away from the wafer, and the drainage groove does not penetrate the wafer holder.

3. The wafer chuck for preventing secondary liquid contamination according to claim 2, characterized in that, The depth of the guide groove gradually increases from the end closer to the wafer to the end farther away from the wafer.

4. The wafer chuck for preventing secondary liquid contamination according to claim 3, characterized in that, The ratio of the minimum width to the maximum width of the guide channel is 0.25 to 0.

5.

5. The wafer chuck for preventing secondary liquid contamination according to claim 3, characterized in that, The flow channel is dumbbell-shaped, and its width decreases and then increases from the end closer to the wafer to the end farther away from the wafer.

6. The wafer chuck for preventing secondary liquid contamination according to claim 2, characterized in that, The drainage groove is a wedge-shaped groove whose depth gradually decreases from the end closer to the wafer to the end farther away from the wafer.

7. The wafer chuck for preventing secondary liquid contamination according to claim 1, characterized in that, The upper surface of the chuck seat is a conical surface.

8. The wafer chuck for preventing secondary liquid contamination according to claim 7, characterized in that, The angle between the generatrix of the cone and the horizontal plane is 2~5°.

9. The wafer chuck for preventing secondary liquid contamination according to claim 1, characterized in that, The upper end of the fixing part is provided with a protrusion with a cross-shaped cross section, and the lower end of the replacement part is provided with a groove, the groove matching the shape of the protrusion of the fixing part.

10. The wafer chuck for preventing secondary liquid contamination according to claim 9, characterized in that, The cross-section of the protrusions of the fixing part in each direction is trapezoidal, and the outer surface of the protrusions of the fixing part in each direction is provided with friction strips.

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