Wafer cleaning device

Abstract

The utility model provides a wafer cleaning device. The wafer cleaning device comprises a cleaning cavity, a liquid storage tank, a vacuum device, a liquid spraying device and a liquid discharging groove. The cleaning cavity is provided with a top, a bottom and a side wall connected with the top and the bottom, the liquid storage tank is used for storing a cleaning solvent and providing the cleaning solvent for the cleaning cavity. The vacuum device is connected with the liquid storage tank so that the liquid storage tank can keep certain negative pressure before the cleaning solvent is provided for the cleaning cavity, and air in the cleaning solvent can be pumped out. The liquid discharging groove is formed in the edge of one side of the bottom of the cleaning cavity. The problem that the liquid spraying device of the wafer cleaning device generates dropping liquid to cause adverse effects on the wafer is effectively solved.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor packaging, and more specifically, to a wafer cleaning device. Background Technology

[0002] Photoresist coating machines often use spin coating. Due to the combined effects of the physical properties of the wafer edges (such as surface tension and material viscosity) and rotational dynamics during the coating process, a significant amount of photoresist material tends to accumulate at the wafer edges, forming what is known as "edge beads" or "edge effect." This not only wastes material but can also adversely affect subsequent processing steps, such as causing contamination or scratching the wafer surface. Therefore, after photoresist coating, a specialized cleaning and thinning process is usually required for the wafer edge areas; this process is called EBR cleaning.

[0003] The purpose of EBR cleaning is to remove excess photoresist material from the wafer edges to avoid unnecessary contamination or impact during subsequent processing. However, this process also faces several challenges due to the characteristics of the solvent and the complexity of the coating machine's piping structure. The physical and chemical properties of the solvent, such as volatility, viscosity, and surface tension, affect its flow behavior in the piping. Simultaneously, the piping system of the coating machine is typically designed to be quite complex to ensure precise and efficient delivery of the solvent to the wafer surface. However, this complexity also increases the risk of air contamination in the piping. Air contamination in the piping causes fluctuations in the solution flow rate because the presence of air bubbles alters the solvent's flow state, making it unstable. Fluctuations in flow rate directly affect the stability of the spraying device, making it difficult to maintain constant spraying pressure and flow rate. This not only reduces the accuracy and uniformity of the spraying but may also cause adverse phenomena such as dripping and splashing. Drips and splashes can damage the integrity of the coating on the wafer surface, resulting in uneven adhesive thickness and even defects in certain areas.

[0004] Inhomogeneity and defects in these coatings can severely impact subsequent electroplating processes. During electroplating, metal ions deposit on the coating surface to form a metal layer. If the coating is uneven or defective, the deposition of the metal layer will also become uneven, leading to defects such as deformation and dimensional abnormalities in metal bumps. These defects not only affect the product's appearance quality but may also weaken its electrical performance and reliability, thereby reducing the product's overall performance and market competitiveness. Utility Model Content

[0005] In view of the problems existing in the prior art described above, this application provides a wafer cleaning apparatus. This effectively solves the dripping problem of the liquid spraying device in a wafer cleaning apparatus.

[0006] To achieve the above and other related objectives, this utility model provides a wafer cleaning apparatus, comprising:

[0007] The cleaning chamber has a top and a bottom that are oppositely arranged, and a side wall connecting the top and the bottom;

[0008] A storage tank is used to store cleaning solvent and supply cleaning solvent to the cleaning chamber;

[0009] A vacuum device, connected to a storage tank, is used to maintain a certain negative pressure in the storage tank before the cleaning solvent is supplied to the cleaning chamber.

[0010] A liquid spraying device is installed inside the cleaning chamber and connected to the liquid storage tank;

[0011] A drain trough is located on one side edge of the bottom of the cleaning chamber.

[0012] Optionally, the spraying device includes:

[0013] The infusion tubing connects to the storage tank and extends into the cleaning chamber;

[0014] The spray needle is located at the end of the infusion tubing that extends into the cleaning chamber;

[0015] The robotic arm is connected to the infusion tube to move the infusion tube and the spray needle within the cleaning chamber.

[0016] Optionally, after cleaning, the robotic arm moves the infusion tube and spray needle horizontally above the drainage tank, then rises to the highest point and returns to the initial position.

[0017] Optionally, the wafer cleaning apparatus further includes: a flow guide plate located inside the cleaning chamber and fixed to the side wall, the flow guide plate being positioned above the drain tank.

[0018] Optionally, when the spraying device is in the initial position, the guide vane is located directly below the spraying end of the spraying device.

[0019] Optionally, the wafer cleaning apparatus further includes: a connecting frame disposed on the side wall of the cleaning chamber, and a flow guide plate fixedly connected to the connecting frame.

[0020] Optionally, the wafer cleaning apparatus also includes:

[0021] A filter is installed on the infusion tubing;

[0022] The backflow shut-off valve is installed on the infusion line, located between the filter and the spray device.

[0023] Optionally, the wafer cleaning device further includes a spray valve, which is mounted on the infusion pipe and located between the filter and the back suction shut-off valve.

[0024] Optionally, the wafer cleaning apparatus also includes:

[0025] The wafer carrier stage, used to hold the wafers to be cleaned, is located inside the cleaning chamber, in the central area at the bottom of the cleaning chamber. The drain tank is located on one side of the wafer carrier stage and is spaced apart from the wafer carrier stage.

[0026] Optionally, the pressure applied by the vacuum device to the liquid storage tank is between -0.08 MPa and -0.06 MPa, and the pressure application time is between 500 s and 700 s.

[0027] As described above, the wafer cleaning apparatus provided by this utility model has at least the following beneficial technical effects:

[0028] This invention relates to a wafer cleaning apparatus comprising a cleaning chamber, a storage tank, a vacuum device, a spraying device, and a drain trough. The cleaning chamber has a top, a bottom, and a sidewall connecting the top and the bottom. The storage tank stores and supplies cleaning solvent to the cleaning chamber. The vacuum device is connected to the storage tank to maintain a negative pressure in the storage tank before supplying cleaning solvent to the cleaning chamber, thereby removing air from the cleaning solvent. The drain trough is located at one edge of the bottom of the cleaning chamber. This invention effectively solves the problem of dripping from the spraying device of a wafer cleaning apparatus causing adverse effects on the wafer. Attached Figure Description

[0029] Figure 1 The diagram shown is a structural diagram of the wafer cleaning apparatus provided in an embodiment of this utility model.

[0030] Figure 2 This utility model is shown. Figure 1 A cross-sectional view from the perspective of AA.

[0031] Figure 3 The image shown is a top view of the interior of the cleaning chamber provided in an embodiment of this utility model.

[0032] Figure Labels

[0033] 1. Cleaning chamber; 11. Top; 12. Bottom; 121. Drainage trough; 13. Side wall; 131. Connecting frame; 1311. Guide vane; 2. Storage tank; 21. Storage valve; 3. Vacuum device; 4. Spraying device; 41. Spraying needle; 42. Infusion tube; 421. Filter; 422. Spraying valve; 423. Back suction shut-off valve; 5. Robotic arm; 6. Wafer carrier stage; 61. Wafer; 7. Support frame. Detailed Implementation

[0034] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model.

[0035] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this utility model. Although the illustrations only show components related to this utility model and are not drawn according to the actual number, shape and size of the components, the shape, quantity, positional relationship and proportion of each component can be arbitrarily changed under the premise of realizing the technical solution of this utility model, and the layout of the components may also be more complex.

[0036] This embodiment provides a wafer cleaning apparatus, referring to... Figures 1 to 3 The wafer cleaning apparatus of this embodiment includes a cleaning chamber 1, a liquid storage tank 2, a vacuum device 3, a liquid spraying device 4, and a liquid draining tank 121.

[0037] Specifically, refer to Figure 1 The cleaning chamber 1 includes a top 11, a bottom 12 and a side wall 13 connecting the top 11 and the bottom 12, which are disposed opposite to each other.

[0038] like Figure 1 As shown, the wafer cleaning apparatus also includes a wafer carrier stage 6. The wafer carrier stage 6 is used to hold the wafer 61 to be cleaned. The wafer carrier stage 6 is disposed inside the cleaning chamber 1, located in the central region of the bottom 12 of the cleaning chamber 1. In an optional embodiment of this example, a support frame 7 is provided between the bottom 12 of the cleaning chamber 1 and the wafer carrier stage 6. The support frame 7 not only provides additional support for the wafer carrier stage 6, but also optimizes the stability of the wafer carrier stage 6 through its structural design. The support frame 7 and the wafer carrier stage 6 are connected by a driving component (not shown in the figure). The driving component can drive the wafer carrier stage 6 to rotate, thereby causing the wafer 61 to rotate, facilitating the cleaning of the wafer 61. Driving the wafer carrier stage 6 to rotate is an important step in the wafer 61 cleaning process. By rotating the wafer 61, the cleaning solvent can more evenly cover the surface of the wafer 61, and at the same time, the centrifugal force is used to more effectively wash away contaminants attached to the surface of the wafer 61, improving cleaning efficiency.

[0039] Reference Figure 1A storage tank 2 is located outside the cleaning chamber 1 and is used to store and supply cleaning solvent to the cleaning chamber 1. A vacuum device 3 is connected to the storage tank 2 to maintain a certain negative pressure in the storage tank 1 before supplying cleaning solvent to the cleaning chamber 1. The storage tank 2 is equipped with a storage valve 21, which controls the entry of cleaning solvent. By opening or closing the storage valve 21, the supply of cleaning solvent can be precisely controlled to meet different cleaning needs. After the storage tank 2 is replenished, the storage valve 21 is first closed to prevent new cleaning solvent or air from entering. Then, the vacuum device 3 is turned on to maintain a negative pressure in the replenished storage tank 2 for a period of time. The purpose of this step is to use the negative pressure environment to expel air bubbles from the cleaning solvent in the storage tank 2. After the air bubbles in the storage tank 2 have been expelled, the vacuum device is turned off. The process then switches to nitrogen pressurization, i.e., nitrogen is used to pressurize the storage tank 2. Nitrogen is an inert gas that does not chemically react with the cleaning solvent, so it can be used to pressurize the storage tank 2 to ensure a stable supply of the cleaning solvent during subsequent use. To fully expel air bubbles from the storage tank 2 without releasing the cleaning solvent, the vacuum device 3 applies a pressure to the storage tank 2 ranging from -0.08 MPa to -0.06 MPa for a duration ranging from 500 s to 700 s.

[0040] Reference Figure 1 and Figure 2 The spraying device 4 is a core component of the wafer cleaning apparatus. It is responsible for delivering cleaning solvent from the storage tank 2 to the surface of the wafer 61 to clean it. In this embodiment, the spraying device 4 is located inside the cleaning chamber 1 and communicates with the storage tank 2. Specifically, the spraying device 4 includes a spraying needle 41, a delivery tube 42, and a robotic arm 5. The delivery tube 42 communicates with the storage tank 2 and extends into the cleaning chamber 1, with the spraying needle 41 located at the end of the delivery tube 42 extending into the cleaning chamber 1. The delivery tube 42 acts as a bridge connecting the storage tank 2 and the spraying needle 41, ensuring that the cleaning solvent can be smoothly delivered from the storage tank 2 to the spraying needle 41. The delivery tube 42 must not only withstand the pressure and flow rate of the cleaning solvent but also ensure that the solvent is not contaminated or lost during transmission. To achieve this, the delivery tube 42 is typically made of corrosion-resistant and high-pressure-resistant materials, and its inner wall is smooth to reduce resistance during solvent transmission. Robotic arm 5 is connected to infusion tube 42, which moves infusion tube 42 and spray needle 41 within cleaning chamber 1. The addition of robotic arm 5 allows spray device 4 to move flexibly within cleaning chamber 1. Through precise control of robotic arm 4, spray device 4 can uniformly spray cleaning solvent onto the surface of wafer 61, avoiding localized over-cleaning or under-cleaning during the cleaning process. This uniformity ensures consistent cleaning quality across all locations on the surface of wafer 61, thereby improving the stability and reliability of the entire cleaning process.

[0041] Reference Figures 1 to 3 The main function of the drain tank 121 is to collect the dripping liquid generated by the spray device 4 after the wafer 61 is cleaned and smoothly discharge it from the cleaning chamber 1. The drain tank 121 is located at one edge of the bottom 12 of the cleaning chamber 1. Specifically, the drain tank 121 is located on one side of the wafer support stage 6 and is spaced apart from the wafer support stage 6. After the wafer 61 is cleaned, the robotic arm 5 moves the infusion tube 42 and the spray needle 41 horizontally above the drain tank 121, then rises to the highest point and returns to the initial position. At this time, if there is dripping liquid from the spray device 4, the dripping liquid will fall into the drain tank 121 and will not affect the process. This layout helps to optimize the flow path of the dripping liquid generated by the spray device 4 after the wafer 61 is cleaned, and improves the efficiency and accuracy of dripping liquid collection.

[0042] Reference Figures 1 to 3 The wafer cleaning apparatus also includes a guide plate 1311, which is located inside the cleaning chamber 1 and fixed to the side wall 13. The guide plate 1311 is positioned above the drain tank 121. In this embodiment, when the spraying device 4 is in its initial position, the guide plate 1311 is located directly below the spraying end of the spraying device 4. The guide plate 1311 is fixed to the side wall 13 via a connecting bracket 131. Specifically, the guide plate 1311 is disposed on the side of the first side wall 131 near the second side wall 132. After the spraying device 4 finishes cleaning the wafer 61, if there is any dripping from the spraying device 4, the dripping will fall onto the guide plate 1311 instead of falling onto the wafer 16 and thus damaging the wafer 16. Perfluoroalkoxyethylene has excellent corrosion resistance and high temperature resistance. To avoid damage to the guide plate 1311 by the cleaning solvent, the guide plate 1311 is a perfluoroalkoxyethylene guide plate.

[0043] Optionally, refer to Figure 1 The wafer cleaning apparatus also includes a filter 421, a backflow stop valve 423, and a spray valve 422. The filter 421 is mounted on the infusion pipe 42 to filter the cleaning solvent flowing through it, removing impurities and particulate matter to ensure the purity of the cleaning solvent, which is crucial to preventing secondary contamination of the wafer 61 surface. The backflow stop valve 423 is also mounted on the infusion pipe 42, located between the filter 421 and the spray device 4. The main function of the backflow stop valve 423 is to prevent the cleaning solvent from flowing back into the filter 421 or the storage tank 2 after cleaning, thereby protecting the filter 421 or the storage tank 2 from contamination. For ease of operation, in an optional embodiment of this example, the backflow stop valve 423 is located outside the cleaning chamber 1. The spray valve 422 is still mounted on the infusion pipe 42, located between the filter 421 and the backflow stop valve 423. The main function of the spray valve 422 is to control the spraying of cleaning solvent. Before cleaning the wafer 61, the spray valve 422 is opened to release the cleaning solvent.

[0044] Reference Figures 1 to 3 This application addresses the issue of dripping from the liquid spraying device 4 in the wafer cleaning apparatus by adding a vacuum device 3 to one end of the liquid storage tank 2. This vacuum device maintains a negative pressure in the liquid storage tank 2 after replenishment, effectively removing air and preventing dripping. Furthermore, a guide vane 1311 is installed on the side wall 13 of the cleaning chamber 1 to direct dripping from the spraying device 4, preventing any impact on the wafer 61. This effectively solves the problem of dripping from the spraying device 4 causing adverse effects on the wafer 61.

[0045] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A wafer cleaning apparatus, characterized in that, include: The cleaning chamber has a top, a bottom, and a sidewall connecting the top and the bottom, which are disposed opposite to each other. A storage tank for storing cleaning solvent and supplying the cleaning solvent to the cleaning chamber; A vacuum device, connected to the liquid storage tank, is provided to maintain a certain negative pressure in the liquid storage tank before providing cleaning solvent to the cleaning chamber. A liquid spraying device is installed inside the cleaning chamber and communicates with the liquid storage tank; A drain trough is provided on one side edge of the bottom of the cleaning chamber.

2. The wafer cleaning apparatus according to claim 1, characterized in that, The liquid spraying device includes: An infusion tube is connected to the storage tank and extends into the cleaning chamber; The spray needle is located at one end of the infusion tube that extends into the cleaning chamber; A robotic arm is connected to the infusion tube to move the infusion tube and the spray needle within the cleaning chamber.

3. The wafer cleaning apparatus according to claim 2, characterized in that, After cleaning, the robotic arm moves the infusion tube and the spray needle horizontally above the drainage tank, then rises to the highest point and returns to the initial position.

4. The wafer cleaning apparatus according to any one of claims 1 to 3, characterized in that, Also includes: A guide vane is located inside the cleaning chamber and fixed to the side wall, with the guide vane positioned above the drain trough.

5. The wafer cleaning apparatus according to claim 4, characterized in that, When the spraying device is in its initial position, the guide vane is located directly below the spraying end of the spraying device.

6. The wafer cleaning apparatus according to claim 4, characterized in that, Also includes: A connecting frame is disposed on the side wall of the cleaning chamber, and the guide vane is fixed to the connecting frame.

7. The wafer cleaning apparatus according to claim 2, characterized in that, Also includes: A filter is installed on the infusion tube; A backflow shut-off valve is installed on the infusion pipe, located between the filter and the spraying device.

8. The wafer cleaning apparatus according to claim 7, characterized in that, Also includes: The injection valve is installed on the infusion tube and located between the filter and the backflow shut-off valve.

9. The wafer cleaning apparatus according to claim 1, characterized in that, Also includes: A wafer carrier stage is used to hold the wafer to be cleaned. The wafer carrier stage is disposed inside the cleaning chamber and located in the central area of ​​the bottom of the cleaning chamber. The drain tank is located on one side of the wafer carrier stage and is spaced apart from the wafer carrier stage.

10. The wafer cleaning apparatus according to claim 1, characterized in that, The pressure applied by the vacuum device to the liquid storage tank is between -0.08 MPa and -0.06 MPa, and the pressure application time is between 500 s and 700 s.

Images