A defoaming device for a medium for drying a wafer

Abstract

The utility model discloses a medium's defoaming device for wafer drying, including medium liquid supply system, heater, the medium liquid supply system is connected to the heater through the pipeline, still include bubble remover, the bubble remover includes the body of having the cavity inside, be located the liquid inlet pipe of the body side upper portion, be located the air outlet pipe of the body top, be located the liquid outlet pipe of the body bottom, the import end of liquid inlet pipe is connected with the heater through the pipeline, and the export end of liquid inlet pipe is worn into the cavity and presents the downward angle extension to be close to the cavity other side inner wall, and the export end of liquid outlet pipe is connected to the place of waiting for drying wafer through the pipeline. Through the defoaming device can eliminate IPA medium after heating or the bubble that exists from CSM process system produces, guarantees the dry medium in the surface of wafer that supplies to have no bubble, ensures the dry effect on the surface of wafer.

Description

Technical Field

[0001] This utility model pertains to wafer drying equipment, specifically relating to a degassing device for a medium used in wafer drying. Background Technology

[0002] In the semiconductor manufacturing industry, the cleaning process is a critical step in ensuring the performance, stability, and high yield of semiconductor devices. Maintaining the temperature stability of the chemical solutions during cleaning is essential for ensuring a uniform and effective reaction between the wafer and the chemical solution.

[0003] In actual cleaning processes, appropriate temperature can accelerate the chemical reaction rate, enhance cleaning efficiency, and ensure the uniformity and stability of the cleaning process. Therefore, precisely controlling the temperature of the chemical solution is a core element in improving the cleaning process. Temperature deviations can cause the reaction rate between the chemical solution and the wafer to be too fast or too slow, resulting in a decrease in yield.

[0004] In advanced manufacturing processes, drying after cleaning can be achieved by using the chemical solution IPA (isopropanol) to displace water on the wafer surface. However, when IPA is heated at high temperatures, its ability to dissolve gases decreases dramatically. Gases originally dissolved in the liquid are forced to precipitate. Furthermore, if the heat source power is too high or heat transfer is uneven during the heating process, the temperature of the inner liquid layer in contact with the heat source will be higher than the liquid temperature, causing violent vaporization in these localized areas and generating bubbles. The presence of bubbles severely affects the surface quality of the wafer. Bubbles prevent the liquid from completely encapsulating the device, resulting in incomplete removal of moisture from the device surface. After the IPA evaporates, the remaining moisture leaves water stains, which is a fatal defect for the wafer. Therefore, IPA degassing is necessary before processing the wafer.

[0005] Currently, common degassing technologies include centrifugal degassing and membrane degassing. Centrifugal degassing requires a centrifuge and a complex control system. Membrane degassing is not suitable for high-temperature media. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a degassing device for wafer drying medium, which eliminates bubbles in the drying medium and ensures that no bubbles in the medium act on the wafer surface during the drying process, thereby avoiding bubble impact on the wafer surface and causing chip defects.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] A degassing device for a wafer drying medium includes a medium supply system and a heater. The medium supply system is connected to the heater via a pipeline. The device also includes a degasser, which includes a body with an internal cavity, an inlet pipe located on the upper side of the body, an outlet pipe located at the top of the body, and an outlet pipe located at the bottom of the body. The inlet end of the inlet pipe is connected to the heater via a pipeline, and the outlet end of the inlet pipe extends into the cavity and downward at an angle to the inner wall of the other side of the cavity. The outlet end of the outlet pipe is connected to the wafer to be dried via a pipeline.

[0009] The downward tilt angle is in the range of 17°±2°.

[0010] The inner wall of the cavity slopes inward from top to bottom.

[0011] The inward tilt angle ranges from 1° to 2°.

[0012] The top of the cavity is shaped like a frustum that slopes inward from bottom to top.

[0013] The inlet end of the outlet pipe extends upward into the cavity and is higher than the bottom surface of the cavity.

[0014] The device body is also equipped with a low-level liquid level sensor and a high-level liquid level sensor. The vent pipe is connected to the exhaust pipe, and the exhaust pipe is equipped with a solenoid valve that is linked to the low-level liquid level sensor and the high-level liquid level sensor.

[0015] The defoamer is made of fluoroplastic material.

[0016] A three-way valve is installed on the pipeline leading from the liquid outlet pipe to the wafer to be dried.

[0017] The degassing device for wafer drying media according to this invention has the following advantages:

[0018] 1. An air bubble remover is added to eliminate air bubbles generated after the IPA medium is heated by the heater or present in the chemical solution supply equipment (CSM) process system, ensuring that the drying medium supplied to the wafer surface is free of air bubbles and ensuring the drying effect of the wafer surface.

[0019] 2. A deaerator is used to eliminate air bubbles in the medium. It has a simple structure and the control system is easy to implement. The deaerator has a small footprint and is easier to install on the machine.

[0020] 3. The entire defoamer is made of fluoroplastic, which has the characteristics of low precipitation and high temperature resistance. It is not only suitable for IPA media, but also for other high-temperature media. Attached Figure Description

[0021] The utility model will now be described in detail with reference to the accompanying drawings and specific embodiments:

[0022] Figure 1 This is a schematic diagram of the degassing device of this utility model;

[0023] Figure 2 This is a schematic diagram of the defoamer of this utility model.

[0024] Figure 3 This is a perspective view of the deaerator of this utility model;

[0025] Figure 4 This is a cross-sectional view of the deaerator of this utility model. Detailed Implementation

[0026] This utility model provides a degassing device for a wafer drying medium, such as... Figures 1-4 As shown, it includes a medium supply system 1 (such as a CSM supply system) and a heater 2 located inside the main unit. The medium supply system 1 is connected to the heater 2 through a pipeline and supplies a drying medium such as IPA into the heater 2. The temperature of the IPA supplied by the medium supply system 1 is 40-50℃, and the temperature of the IPA reaches 70-75℃ after passing through the heater 2.

[0027] Unlike existing technologies, this degassing device also includes a degasser 3, connected to a valve located at the terminal of the main unit. The degasser 3 specifically includes a body 32 with an internal cavity 31, an inlet pipe 33 located on the upper side of the body 32, an outlet pipe 34 located at the top of the body 32, and an outlet pipe 35 located at the bottom of the body 32. Utilizing the physical property that air bubbles in a liquid rise upwards, the gas and liquid in the medium are statically separated. The inlet end of the inlet pipe 33 is connected to the heater 2 via a pipeline to receive the heated gas-liquid mixture. The high-temperature gas-liquid mixture enters the interior of the degasser 3 through the inlet pipe 33. The outlet end of the inlet pipe 33 penetrates into the cavity 31 and extends downwards at an angle to the inner wall near the other side of the cavity 31. This directs the liquid to the inner wall of the cavity 31 of the degasser 3, allowing the medium to flow along the inner wall of the cavity 31. The purpose is to reduce or eliminate the free fall of liquid caused by the suspension of the pipe in the gas-liquid mixture, which leads to the impact and splashing of the liquid column, entraining air into the liquid and forming a large number of entrained bubbles. After the gas-liquid two-phase mixture enters the demister 3, under the action of gravity, a density difference exists between the bubbles and the liquid, causing separation. The bubbles move upward under the action of buoyancy, while the liquid sinks downward under the action of gravity, thus achieving gas-liquid separation. The preferred range for the downward tilt angle is designed to be 17°±2°.

[0028] Because the surface tension of a liquid decreases with increasing temperature, bubble formation becomes relatively easy in high-temperature, low-surface-tension environments. Therefore, the inner wall of cavity 31 is designed to slope inwards from top to bottom. This allows bubbles adhering to the inner wall of cavity 31 to move upwards and escape from the liquid surface more easily. The preferred inward slope angle is between 1° and 2°.

[0029] The top of cavity 31 is shaped like a frustum that slopes inward from bottom to top. This structure provides a guiding flow path for the rising gas, allowing it to quickly converge and be discharged from the outlet pipe 34. This effectively prevents gas from accumulating in the dead corner at the top and improves exhaust efficiency. Furthermore, the top can guide the liquid that has accumulated vapor along the wall of cavity 31 in a laminar flow, avoiding the risk of droplets falling directly from a height, impacting the liquid surface, and carrying away gas, thus preventing the formation of secondary bubbles.

[0030] The body 32 is also equipped with a low-level liquid level sensor 4 and a high-level liquid level sensor 5. An exhaust pipe 34 connects to an exhaust pipe 6, which is equipped with a pneumatic solenoid valve 7 that is linked to the low-level liquid level sensor 4 and the high-level liquid level sensor 5. When a signal is received from the low-level liquid level sensor 4, it indicates that the liquid level of the medium inside the deaerator 3 has reached the position of the low-level liquid level sensor 4. At this time, the solenoid valve 7 is opened to allow air to pass through, venting the gas inside the deaerator 3 through the exhaust pipe 34. When the liquid level of the medium inside the deaerator 3 reaches the position of the high-level liquid level sensor 5, the high-level liquid level sensor 5 sends a signal, which then closes the solenoid valve 7. This cycle repeats, achieving automatic venting of the deaerator 3.

[0031] The inlet end of the outlet pipe 35 extends upward into the cavity 31 and is higher than the bottom surface of the cavity 31. This elevated design ensures that there is a region between the liquid outlet and the bottom of the cavity 31, effectively eliminating the risk of air bubbles adhering to the bottom surface being carried away by the outlet liquid flow, thus ensuring that the liquid outlet is bubble-free. The outlet end of the outlet pipe 35 is connected to the wafer to be dried via a pipeline. A three-way valve is also installed on this pipeline. After passing through the defoamer 3, the medium enters the three-way valve 8 and finally acts on the wafer surface to achieve the drying of the wafer surface.

[0032] In addition, the entire defoamer 3, including its cavity 31, inlet and outlet pipes 35, and outlet pipe 34, is made of fluoroplastic material, which has the characteristics of low precipitation and high temperature resistance. It is not only suitable for IPA media, but also for other high-temperature media.

[0033] However, those skilled in the art should recognize that the above embodiments are only used to illustrate the present utility model and are not intended to limit the present utility model. Any changes or modifications to the above embodiments within the scope of the essential spirit of the present utility model will fall within the scope of the claims of the present utility model.

Claims

1. A degassing device for a wafer drying medium, comprising a medium supply system and a heater, wherein the medium supply system is connected to the heater via a pipeline, characterized in that: It also includes a defoamer, which includes a body with an internal cavity, an inlet pipe located on the upper side of the body, an outlet pipe located at the top of the body, and an outlet pipe located at the bottom of the body. The inlet end of the inlet pipe is connected to the heater via a pipeline, and the outlet end of the inlet pipe extends into the cavity and extends at a downward angle to the inner wall of the other side of the cavity. The outlet end of the outlet pipe is connected to the wafer to be dried via a pipeline.

2. The degassing device for a wafer drying medium according to claim 1, characterized in that: The downward tilt angle is in the range of 17°±2°.

3. The degassing device for a wafer drying medium according to claim 1, characterized in that: The inner wall of the cavity slopes inward from top to bottom.

4. The degassing device for a wafer drying medium according to claim 3, characterized in that: The inward tilt angle ranges from 1° to 2°.

5. The degassing device for a wafer drying medium according to claim 1, characterized in that: The top of the cavity is shaped like a frustum that slopes inward from bottom to top.

6. The degassing device for a wafer drying medium according to claim 1, characterized in that: The inlet end of the outlet pipe extends upward into the cavity and is higher than the bottom surface of the cavity.

7. The degassing device for a wafer drying medium according to claim 1, characterized in that: The device body is also equipped with a low-level liquid level sensor and a high-level liquid level sensor. The vent pipe is connected to the exhaust pipe, and the exhaust pipe is equipped with a solenoid valve that is linked to the low-level liquid level sensor and the high-level liquid level sensor.

8. The degassing device for a wafer drying medium according to claim 1, characterized in that: The defoamer is made of fluoroplastic material.

9. A degassing device for a wafer drying medium according to claim 1, characterized in that: A three-way valve is installed on the pipeline leading from the liquid outlet pipe to the wafer to be dried.

Images