Wafer segmented flow field cleaning system

Abstract

The application discloses a wafer segmented flow field cleaning system, which comprises a wafer cleaning tank, a nitrogen heating device, an isopropyl alcohol heating device, a mixing device and a buffer backflow device, the nitrogen heating device is connected with a nitrogen conveying pipeline, the isopropyl alcohol heating device is connected with an isopropyl alcohol conveying pipeline, the top of the wafer cleaning tank is provided with an upper cover cabin, the nitrogen conveying pipeline and the isopropyl alcohol conveying pipeline are communicated with the upper cover cabin, the mixing device is used for mixing isopropyl alcohol and nitrogen, the mixing device and the buffer backflow device are communicated through a circulating pipeline and are used for realizing isopropyl alcohol supply backflow and output, the wafer cleaning tank internally bears a wafer, and the bottom of the wafer cleaning tank is provided with a liquid discharge port and a gas discharge port. The application sets a heating device in the mixing device to control the concentration of the isopropyl alcohol and nitrogen mixture, thereby improving the drying efficiency and enhancing the tension of the mixture, and ensuring that water molecules can effectively remove the surface of the wafer.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor cleaning technology, and specifically relates to a wafer segmented flow field cleaning system. Background Technology

[0002] With the increasing demand for semiconductor wafer cleaning technology, wafer drying technology is indispensable, and different wafer cleaning technologies are required for different wafer products. Wafer drying is the final step in the wet cleaning process, and it is necessary to ensure the effective removal of residual moisture from the wafer surface and maintain the cleanliness of the wafer surface. There are various methods suitable for wafer drying processes, but achieving effective batch drying within a specified time affects the efficiency of the overall wafer cleaning process. Therefore, establishing an effective wafer drying method is a particularly important aspect of wafer wet cleaning technology. Summary of the Invention

[0003] To address the problems existing in the prior art, the present invention provides a wafer segmented flow field cleaning system. The present invention uses a gas phase replacement process of organic solvent isopropanol and nitrogen to allow isopropanol to fully remove residual moisture from the wafer surface, thereby accelerating the drying efficiency of the wafer surface through gas release and diffusion.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] This invention provides a segmented flow field cleaning system for wafers, including a wafer cleaning tank, a nitrogen heating device, an isopropanol heating device, a mixing device, and a buffer reflux device. The nitrogen heating device is connected to a nitrogen delivery pipeline, and the isopropanol heating device is connected to an isopropanol delivery pipeline. The top of the wafer cleaning tank is provided with a top cover chamber. The nitrogen delivery pipeline and the isopropanol delivery pipeline are connected to the top cover chamber. The mixing device is used to mix isopropanol and nitrogen. The mixing device and the buffer reflux device are connected through a circulation pipeline to realize the supply, reflux, and output of isopropanol. The wafer cleaning tank carries wafers inside, and the bottom of the wafer cleaning tank is provided with a liquid discharge port and a gas discharge port.

[0006] As a preferred technical solution, the mixing device is equipped with a heating mechanism, which is a composite aluminum alloy structural component, and a thermocouple temperature controller is installed on the outside of the mixing device.

[0007] As a preferred technical solution, the wafer cleaning tank is provided with a swing mechanism, which includes a drive motor, a sliding rail, a sliding block, a shaft-connected rail, and a swing arm. The sliding rail is arranged parallel to the shaft-connected rail and is located above the shaft-connected rail. The sliding block is slidably mounted on the sliding rail. The drive motor is used to control the sliding block to reciprocate on the sliding rail. At least two swing arms are provided, each including a first arm and a second arm arranged in parallel. The upper part of the first arm is provided with a sliding groove along its length. A sliding wheel is correspondingly mounted on the sliding block and installed in the sliding groove. The lower end of the first arm is axially mounted to the connection point on the shaft-connected rail. The lower end of the second arm is provided with a wafer carrying area.

[0008] As a preferred technical solution, the swing angle of the swing arm is 15-30 degrees.

[0009] As a preferred technical solution, the length of the second arm is greater than the length of the first arm, and the wafer carrier area is located on the side of the second arm away from the first arm.

[0010] As a preferred technical solution, the wafer carrier area has a hollow structure.

[0011] As a preferred technical solution, the upper cover chamber and the wafer cleaning tank are hinged openable structures.

[0012] As a preferred technical solution, the bottom of the mixing device has a funnel-shaped structure, a nitrogen inlet is provided on one side of the mixing device, and an isopropanol inlet is provided on the other side, with three nitrogen inlets.

[0013] As a preferred technical solution, the height of the isopropanol inlet is higher than the height of the nitrogen inlet.

[0014] Compared with the prior art, the present invention has the following technical effects:

[0015] (1) The present invention sets a heating device in the mixing device to control the concentration of the isopropanol and nitrogen mixture, thereby improving the drying efficiency, enhancing the tension of the mixture, and ensuring that water molecules can be effectively removed from the surface of the wafer.

[0016] (2) The present invention forms an arc-shaped motion path through a swing mechanism, so that the wafer forms a special vibration and swing during the swing process. The effective swing amplitude makes the setting of the cleaning equipment more flexible and improves the universality and feasibility of general wet process construction.

[0017] (3) When the water molecules in the structured pattern on the wafer surface of the present invention are dried, before the water molecules are gradually carried away from the wafer surface, the periodic high-temperature nitrogen gas jet makes the water molecules quickly carried away from the tank under the control of the circulating airflow force that has been continuously and intermittently oscillating by the isopropanol molecules, thus achieving the drying effect. Attached Figure Description

[0018] 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 of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the wafer segmented flow field cleaning system of the present invention.

[0020] Figure 2 This is a schematic diagram of the wafer cleaning tank of the present invention.

[0021] Figure 3 This is one of the structural schematic diagrams of the swing mechanism of the present invention.

[0022] Figure 4 This is the second schematic diagram of the swing mechanism of the present invention.

[0023] Figure 5 This is a simplified kinematic diagram of the swing mechanism of the present invention.

[0024] Figure 6 This is a schematic diagram of the mixing device of the present invention.

[0025] The specific reference numerals in the attached drawings are explained as follows: 1. Wafer cleaning tank; 2. Upper cover chamber; 3. Drive motor; 4. Sliding rail; 5. Sliding block; 6. Shaft-connected rail; 7. Swing arm; 8. Sliding groove; 9. Wafer carrying area; 10. First support arm; 11. Second support arm; 12. Mixing device; 13. Nitrogen inlet; 14. Nitrogen delivery pipe; 15. Buffer reflux device; 16. Nitrogen heating device; 17. Isopropanol heating device; 18. Isopropanol delivery pipe; 19. Liquid discharge port; 20. Gas discharge port. Detailed Implementation

[0026] 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.

[0027] This embodiment provides a segmented flow field cleaning system for wafers, including a wafer cleaning tank 1, a nitrogen heating device 16, an isopropanol heating device 17, a mixing device 12, and a buffer reflux device 15. The nitrogen heating device 16 is connected to a nitrogen delivery pipe 14, and the isopropanol heating device 17 is connected to an isopropanol delivery pipe 18. A top cover chamber 2 is provided on the top of the wafer cleaning tank 1. The nitrogen delivery pipe 14 and the isopropanol delivery pipe 18 are connected to the top cover chamber 2. The mixing device 12 is used to mix isopropanol and nitrogen. The mixing device 12 is connected to the buffer reflux device 15 through a circulation pipeline to realize the supply, reflux, and output of isopropanol. The wafer cleaning tank 1 contains wafers, and the bottom of the wafer cleaning tank 1 is provided with a liquid discharge port 19 and a gas discharge port 20. A heating mechanism is provided inside the mixing device 12. The heating mechanism is a composite aluminum alloy structural component, and a thermocouple temperature controller is provided outside the mixing device 12. The bottom of the mixing device 12 has a funnel-shaped structure. A nitrogen inlet 13 is provided on one side of the mixing device 12, and an isopropanol inlet is provided on the other side. There are three nitrogen inlets 13, and the height of the isopropanol inlet is higher than the height of the nitrogen inlet 13.

[0028] The wafer cleaning tank 1 is equipped with a swing mechanism, which has two wafer cassette holding areas 9 for placing wafer cassettes. The outer shell of the wafer cleaning tank 1 is made of metal.

[0029] In this embodiment, the swing mechanism includes a drive motor 3, a sliding rail 4, a sliding block 5, a shaft-connected rail 6, and a swing arm 7. The sliding rail 4 is arranged parallel to the shaft-connected rail 6 and is located above the shaft-connected rail 6. The sliding block 5 is slidably mounted on the sliding rail 4. The drive motor 3 is used to control the sliding block 5 to reciprocate on the sliding rail 4.

[0030] Two swing arms 7 are provided. The swing arms 7 include a first arm 10 and a second arm 11 arranged in parallel. The upper part of the first arm 10 is provided with a sliding groove 8 along the length direction. A sliding wheel is installed on the sliding block 5. The sliding wheel is installed in the sliding groove 8. The lower end of the first arm 10 is connected to the connection point on the shaft rail 6. The wafer box bearing area is located at the lower end of the second arm 11.

[0031] The motion process in this embodiment is as follows: the drive motor 3 drives the sliding block 5 to move along the sliding track 4, and the movement of the sliding block 5 drives the sliding wheel to slide along the sliding groove 8, so that the swing arm 7 swings along the shaft connection point on the shaft connection track 6 to realize the simple harmonic motion of the wafer.

[0032] In this embodiment, the length of the second arm 11 is greater than the length of the first arm 10. This arrangement increases the swing amplitude of the wafer, with the swing angle of the swing arm 7 ranging from 15 to 30 degrees, achieving better drying. The wafer cassette carrier is located on the side of the second arm 11 away from the first arm 10, avoiding mutual interference during movement. The bottom of the wafer cleaning tank 1 is provided with a vent, and the top of the wafer cleaning tank 1 is provided with a top cover 2, which is axially connected to the wafer cleaning tank 1. The cleaning agent in the wafer cleaning tank 1 is a mixture of nitrogen and isopropanol, and the wafer cassette carrier area 9 has a hollow structure. This invention achieves micro-oscillation of the wafer through a swing-type motion mechanism, allowing water molecules within the specially patterned high aspect ratio structure to continuously break the surface tension between the water molecules and the high aspect ratio pore structure through the interaction of heated nitrogen and isopropanol during the drying process. Conversely, this causes the capillary action of water molecules in the vacant areas to be continuously precipitated, resulting in a water molecule replacement drying reaction.

[0033] The cleaning process in this embodiment is as follows:

[0034] This embodiment provides a simple harmonic motion type wafer cleaning and drying method, including the following steps:

[0035] Step 1: Place the wafer in wafer cleaning tank 1 and close wafer cleaning tank 1 to form a sealed structure;

[0036] Step 2: Purge nitrogen into wafer cleaning tank 1. After the nitrogen purge is completed, pour ultrapure water into wafer cleaning tank 1 to wet the wafer.

[0037] Step 3: Drain the ultrapure water, blow isopropanol into wafer cleaning tank 1, and then pour ultrapure water into wafer cleaning tank 1 again to wet the wafer.

[0038] Step 4: Drain the ultrapure water, blow isopropanol into the wafer cleaning tank 1 again, and then pour ultrapure water into the wafer cleaning tank 1 again to wet the wafer. The wafer will then perform simple harmonic motion under the drive of the oscillating mechanism.

[0039] Step 5: The heated mixture of isopropanol and nitrogen is blown into the wafer cleaning tank 1, and ultrapure water is discharged.

[0040] Step 6: While the wafer is in simple harmonic motion, continue to blow a mixture of isopropanol and nitrogen into the wafer cleaning tank 1 until the wafer surface is dry, and then position the wafer.

[0041] Although the above embodiments have provided a detailed description of the present invention, it should be understood by those skilled in the art that modifications or improvements can be made based on the disclosure of the present invention without departing from the spirit and scope of the invention, and such modifications and improvements are all within the spirit and scope of the present invention.

Claims

1. A wafer segmented flow field cleaning system, characterized in that, The device includes a wafer cleaning tank, a nitrogen heating device, an isopropanol heating device, a mixing device, and a buffer reflux device. The nitrogen heating device is connected to a nitrogen supply pipeline, and the isopropanol heating device is connected to an isopropanol supply pipeline. The wafer cleaning tank has a top cover chamber, and the nitrogen and isopropanol supply pipelines are connected to the top cover chamber. The mixing device is used to mix isopropanol and nitrogen. The mixing device and the buffer reflux device are connected via a circulation pipeline to achieve the supply, reflux, and output of isopropanol. The wafer cleaning tank holds wafers, and the bottom of the wafer cleaning tank has a liquid discharge port and a gas discharge port. A swing mechanism is installed inside the wafer cleaning tank. The device includes a drive motor, a sliding rail, a sliding block, a shaft-connected rail, and a swing arm. The sliding rail is parallel to the shaft-connected rail and is located above the shaft-connected rail. The sliding block is slidably mounted on the sliding rail. The drive motor controls the sliding block to reciprocate on the sliding rail. At least two swing arms are provided. Each swing arm includes a first arm and a second arm arranged in parallel. The upper part of the first arm has a sliding groove along its length. A sliding wheel is correspondingly mounted on the sliding block and installed in the sliding groove. The lower end of the first arm is axially mounted to the connection point on the shaft-connected rail. The lower end of the second arm has a wafer carrier area.

2. The wafer segmented flow field cleaning system as described in claim 1, characterized in that, The mixing device is equipped with a heating mechanism, which is a composite aluminum alloy structural component, and a thermocouple temperature controller is installed on the outside of the mixing device.

3. The wafer segmented flow field cleaning system as described in claim 1, characterized in that, The swing angle of the swing arm is 15-30 degrees.

4. The wafer segmented flow field cleaning system as described in claim 1, characterized in that, The length of the second arm is greater than the length of the first arm, and the wafer carrier area is located on the side of the second arm away from the first arm.

5. The wafer segmented flow field cleaning system as described in claim 1, characterized in that, The wafer carrier area has a hollow structure.

6. The wafer segmented flow field cleaning system as described in claim 1, characterized in that, The upper cover and the wafer cleaning tank are hinged and openable.

7. The wafer segmented flow field cleaning system as described in claim 1, characterized in that, The bottom of the mixing device has a funnel-shaped structure. A nitrogen inlet is provided on one side of the mixing device, and an isopropanol inlet is provided on the other side. There are three nitrogen inlets.

8. The wafer segmented flow field cleaning system as described in claim 7, characterized in that, The height of the isopropanol inlet is higher than the height of the nitrogen inlet.

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