Wafer drying gas mixing device

Abstract

The application provides a wafer drying gas mixing device, and relates to the technical field of wafer production equipment.The wafer drying gas mixing device comprises an outer shell body with a mixing chamber inside, an isopropyl alcohol injection port arranged at the top of the outer shell body, a nitrogen gas injection port arranged on the outer shell body, and a mixed gas output port; a rotating body is arranged in the mixing chamber, and stirring blades are arranged on the outer wall of the rotating body; a bearing inner plate corresponding to the stirring blades is arranged in the mixing chamber, the bearing inner plate is provided with annular overflow teeth, downwardly extending flow guide plates are arranged on the two sides of the bearing inner plate, and through holes are formed in the flow guide plates.The application does not need external driving and dynamic sealing, the isopropyl alcohol is uniformly overflowed through the overflow teeth, forms a large-area descending liquid film through the flow guide plates, and is fully mixed with the nitrogen gas, so that the concentration and temperature uniformity of the mixed gas body are improved, and the production efficiency is improved.

Description

Technical Field

[0001] This application belongs to the field of wafer manufacturing equipment technology, and in particular relates to a wafer drying gas mixing device. Background Technology

[0002] Marangoni drying refers to the anhydrous drying of wafers or thin films by using a surface tension gradient (Marangoni effect) to drive liquid flow. In semiconductor wafer drying, the typical procedure is as follows: the wafer is first immersed in deionized water, with isopropanol (IPA) vapor covering the surface. Due to the surface tension of IPA (approximately 20.9 × 10⁻⁶ at 25°C), the surface tension of the IPA is significantly reduced. -3 The N / m ratio is much lower than that of water (72.8 × 10 N / m). -3 (N / m) forms a surface tension gradient at the interface where the wafer and water come into contact, "pulling" the water back downwards, while IPA replaces water molecules to cover the wafer surface, achieving drying.

[0003] Marangoni drying requires the use of a mixture of isopropanol and nitrogen vapor, thus necessitating a mixing device to heat and evaporate the isopropanol and mix it with nitrogen.

[0004] In existing isopropanol and nitrogen mixing devices, a liquid outlet corresponding to a guide plate is provided on the conveying pipe. Isopropanol enters the guide plate through this liquid outlet. Since the liquid outlet is intermittently arranged, when the flow rate of isopropanol at the liquid outlet is slow, the isopropanol located near the conveying pipe on the guide plate has difficulty flowing out quickly, resulting in low mixing efficiency. Summary of the Invention

[0005] This application aims to solve the aforementioned technical problems. To this end, this application proposes a wafer drying gas mixing device that can improve mixing efficiency.

[0006] The technical solution adopted by this application to solve its technical problem is:

[0007] A wafer drying gas mixing device, comprising:

[0008] An outer casing having a mixing chamber within it;

[0009] The top of the outer shell is provided with an isopropanol injection port, which is connected to the mixing chamber and is used to supply isopropanol liquid to the mixing chamber.

[0010] The outer casing is also provided with a nitrogen injection port and a mixed gas output port. The nitrogen injection port is used to inject heated nitrogen into the mixing chamber, and the mixed gas output port is used to discharge the mixed gas in the mixing chamber.

[0011] At least one inner support plate is provided in the mixing chamber, and a vertically arranged fixed shaft is provided in the mixing chamber. The rotating body is sleeved on the fixed shaft, and one end of the fixed shaft is fixed to the top of the outer shell to form an isopropanol injection port. The rotating body can rotate when nitrogen and / or isopropanol is supplied. The rotating body is provided with stirring blades, and when the rotating body rotates, the stirring blades can stir the isopropanol liquid located around the rotating body on the inner support plate.

[0012] Preferably, in the wafer drying gas mixing device of this application, the rotating body is provided with an inclined nozzle, and when isopropanol is sprayed out of the inclined nozzle, it can drive the rotating body to rotate.

[0013] Preferably, in the wafer drying gas mixing device of this application, the inclined nozzles are a plurality of nozzles inclined in the same direction.

[0014] Preferably, in the wafer drying gas mixing device of this application, the rotating body is provided with a pushing blade, and the nitrogen injection port is provided on the side wall of the outer shell. The nitrogen injection port is aligned with the pushing blade. When nitrogen is injected into the mixing chamber along the nitrogen injection port, it can push the pushing blade and thus drive the rotating body to rotate.

[0015] Preferably, in the wafer drying gas mixing device of this application, the fixed shaft is provided with a plurality of flow ports. When isopropanol is injected from the isopropanol injection port, it flows through the hollow part of the fixed shaft and the flow ports into the gap space between the outer wall of the fixed shaft and the rotating body, and then is ejected through the inclined nozzle.

[0016] Preferably, in the wafer drying gas mixing device of this application, the inner plate of the support is provided with annular overflow teeth. When the isopropanol liquid fills the space inside the overflow teeth, the isopropanol liquid will flow out from the gap between the overflow teeth to the area outside the overflow teeth on the inner plate of the support.

[0017] Preferably, in the wafer drying gas mixing device of this application, guide plates are provided on both sides of the inner support plate, and baffles are provided on both sides of the inner support plate where guide plates are not provided. Isopropanol flowing to the area outside the overflow teeth on the inner support plate can flow through the through holes of the guide plates to the outside of the guide plates and flow down along the outer wall of the guide plates.

[0018] Preferably, in the wafer drying gas mixing device of this application, the bottom of the guide plate has a bent portion that bends toward the center of the outer casing.

[0019] Preferably, in the wafer drying gas mixing device of this application, the fixed shaft is located in the middle of the inner bearing plate.

[0020] Preferably, in the wafer drying gas mixing apparatus of this application, the rotating body is made of a self-lubricating material.

[0021] The beneficial effects of this application are:

[0022] (i) The wafer drying gas mixing device of this application includes an outer shell with an internal mixing chamber, an isopropanol inlet located on the top of the outer shell, a nitrogen inlet located on the outer shell, and a mixed gas outlet. A rotating body is disposed within the mixing chamber, and stirring blades are disposed on the outer wall of the rotating body. A supporting inner plate corresponding to the stirring blades is disposed within the mixing chamber. The supporting inner plate has annular overflow teeth, and downward-extending guide plates are disposed on both sides of the supporting inner plate, with through holes on the guide plates. This application eliminates the need for external drive and dynamic seals. Isopropanol overflows uniformly through the overflow teeth, forms a large-area descending liquid film through the guide plates, and is thoroughly mixed with nitrogen, improving the concentration and temperature uniformity of the mixed gas and increasing production efficiency.

[0023] (ii) The rotating body is driven by the reaction force of isopropanol when it is sprayed from the tilted nozzle, eliminating the need for an external motor, drive shaft and dynamic seal structure. This fundamentally avoids the risk of wafer contamination by wear particles from the dynamic seal and isopropanol leakage. Moreover, the rotation speed is adaptive with the injection pressure, eliminating the need for additional control links and stirring energy consumption.

[0024] (iii) Several unidirectional inclined nozzles form a combined force, making the driving torque of the rotating body more continuous and stable, increasing the circumferential spray coverage area, and enhancing local disturbance and mixing uniformity.

[0025] (iv) Provides another self-driven path for nitrogen jet-driven rotation, which can be selected or superimposed with the reaction force of isopropanol, and promotes the blades to quickly disperse nitrogen and accelerate gas-liquid contact, thereby further improving mixing efficiency.

[0026] (v) Isopropanol is directionally conveyed through the hollow channel of the fixed shaft and the flow port and then sprayed from the inclined nozzle, realizing the integration of supply and drive, with a compact layout and ensuring uniform circumferential spraying and stable rotation.

[0027] (vi) The annular overflow teeth form a uniform overflow weir, which makes the isopropanol spread evenly into a large area and uniform thickness of descending liquid film, increasing the gas-liquid contact area and improving the concentration and temperature uniformity of the mixed gas.

[0028] (vii) The guide plate and baffle work together to constrain the liquid into a continuous downward liquid film, which smoothly transitions through the through hole and prolongs the gas-liquid contact time, avoiding disorderly dripping and direct scouring of the rotating body.

[0029] (viii) The bending part buffers and guides the liquid film in a concentric direction, extending the contact path, reducing splash impact, and maintaining the stability of the liquid film.

[0030] (ix) The fixed shaft is centered to ensure that the stirring force is balanced, avoids eccentric vibration, and ensures that the stirring of the inner plates of each layer is uniform.

[0031] (x) The rotating body is made of self-lubricating materials such as PTFE, which has low frictional resistance, no need for external lubrication medium, wear resistance and strong chemical inertness, thus improving the reliability and cleanliness of long-term operation. Attached Figure Description

[0032] The technical solution of this application will be further described below with reference to the accompanying drawings and embodiments.

[0033] Figure 1 This is a perspective view of the wafer drying gas mixing apparatus according to an embodiment of this application;

[0034] Figure 2 This is a longitudinal sectional view of the wafer drying gas mixing apparatus according to an embodiment of this application;

[0035] Figure 3 This is a perspective view of the inner support plate and the guide plate according to an embodiment of this application;

[0036] Figure 4 This is a perspective view of the rotating body according to an embodiment of this application;

[0037] Figure 5 This is a cross-sectional view of the tilting direction of the tilted nozzle in an embodiment of this application;

[0038] Figure 6 This is a longitudinal sectional view of the assembly of the rotating body and the fixed shaft according to an embodiment of this application;

[0039] Figure 7 This is a schematic diagram showing the arrangement of the nitrogen injection port in this application.

[0040] The attached figures are labeled as follows:

[0041] 100 - Outer shell;

[0042] 101 - Mixed gas outlet;

[0043] 102 - Liquid level tube;

[0044] 103 - Temperature sensor;

[0045] 105 - Box;

[0046] 106-Cap;

[0047] 107 - Sealing ring;

[0048] 110 - Reinforcing rib;

[0049] 120-Isopropanol injection port;

[0050] 122 - Rotational body;

[0051] 130 - Nitrogen injection port;

[0052] 140 - Mixed Chamber;

[0053] 210 - Load-bearing inner plate;

[0054] 211-Overflow tooth;

[0055] 212-Baffle;

[0056] 220-Blower plate;

[0057] 221 - Through hole;

[0058] 222 - Bending section;

[0059] 230 - Fixed shaft;

[0060] 231 - Flow port;

[0061] 232 - Gap space;

[0062] 1220 - Hollow space;

[0063] 1221 - Inclined nozzle;

[0064] 1222 - Stirring blades;

[0065] 1223 - Propeller blade. Detailed Implementation

[0066] To facilitate understanding of this application, a more comprehensive description will be provided below with reference to the accompanying drawings. The drawings illustrate preferred embodiments of this application. However, this application can be implemented in many different forms and is not limited to the specific embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0067] It should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "phase," and "connection" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0068] The technical solution of this application will now be described in detail with reference to the accompanying drawings and embodiments.

[0069] Example

[0070] This embodiment provides a wafer drying gas mixing device for thoroughly mixing nitrogen and evaporated isopropanol to form a mixed gas, thereby achieving a better drying effect on the wafer.

[0071] The structure of the wafer drying gas mixing device is as follows: Figure 1 As shown, it includes:

[0072] The outer casing 100 has a mixing chamber 140 inside, which is used to mix nitrogen and isopropanol to generate a mixed gas. Several reinforcing ribs 110 may also be provided on the outer side of the outer casing 100. A liquid level pipe 102 is provided on the outer casing 100, with its two ends located at the top and bottom of the outer casing 100 and communicating with the mixing chamber 140. A temperature sensor 103 is also provided on the outer casing 100 to detect the temperature inside the mixing chamber 140. The outer casing 100 consists of a box body 105 and a cover 106. The cover 106 is fixed to the box body 105 by several screws. A sealing ring 107 is provided between the box body 105 and the cover 106. The reinforcing ribs 110 are provided on the outer wall of the box body 105. The box body 105 and the cover 106 are made of stainless steel.

[0073] The top of the outer casing 100 is provided with an isopropanol inlet 120, which is connected to the mixing chamber 140 and is used to supply isopropanol liquid to the mixing chamber 140.

[0074] The outer shell 100 is also provided with a nitrogen injection port 130 to inject heated nitrogen into the mixing chamber 140. There are several nitrogen injection ports 130, which are distributed on the top and side walls of the outer shell 100.

[0075] The mixed gas outlet 101 is connected to the mixing chamber 140 and is used to discharge the mixed gas in the mixing chamber 140.

[0076] At least one load-bearing inner plate 210 is provided within the mixing chamber 140 (e.g. Figure 2 and Figure 3 As shown, the inner plate has three parallel inner support plates 210 (the multiple inner support plates 210 increase the flat area of ​​isopropanol and improve the mixing efficiency). The inner support plates 210 are provided with guide plates 220 on both sides. The inner support plates 210 without guide plates 220 are provided with baffles 212 on both sides. The inner support plates 210 are provided with annular overflow teeth 211. When the isopropanol liquid fills the space inside the overflow teeth 211, the isopropanol liquid will flow out from the gap between the overflow teeth 211 to the area outside the overflow teeth 211 on the inner support plates 210, and flow through the through holes 221 of the guide plates 220 to the outside of the guide plates 220, and flow down along the outer wall of the guide plates 220. During the process of flowing down along the guide plates 220, the isopropanol can be fully mixed with nitrogen. The bottom of the deflector 220 has a bent portion 222 that bends toward the center of the outer casing 100. The bent portion 222 provides a certain buffering effect, preventing isopropyl alcohol from dripping directly.

[0077] like Figure 4-6 As shown, a vertically arranged fixed shaft 230 is provided inside the mixing chamber 140. A rotating body 122 is sleeved on the fixed shaft 230. One end of the fixed shaft 230 is fixed to the top of the outer casing 100, forming an isopropanol injection port 120. The other end of the fixed shaft 230 is closed. The rotating body 122 has inclined nozzles 1221 that tilt in the same direction (viewed in plane, they are all inclined clockwise or counterclockwise, such as...). Figure 5 As shown, when the inclined nozzle 1221 sprays isopropanol, it can drive the rotating body 122 to rotate. The outer wall of the rotating body 122 is equipped with stirring blades 1222. When the rotating body 122 rotates, the stirring blades 1222 can agitate the isopropanol liquid located around the rotating body 122 on the inner support plate 210, improving the fluidity of the isopropanol liquid near the rotating body 122. Simultaneously, the agitation energy of the stirring blades 1222 can accelerate the volatilization of isopropanol to a certain extent. Each set of stirring blades 1222 corresponds to one inner support plate 210. When there are three inner support plates 210, there are also three sets of stirring blades 1222. It should be noted that the shape of the stirring blades 1222 can be varied; generally, they are designed with an inclined surface tilted in one direction.

[0078] As an alternative implementation for driving the rotating body 122 to rotate, a pusher blade 1223 can also be provided on the rotating body 122. In this case, the nitrogen injection port 130 is provided on the side wall of the outer casing 100 (i.e., the housing 105), and the nitrogen injection port 130 is aligned with the pusher blade 1223. When nitrogen is injected into the mixing chamber 140 along the nitrogen injection port 130, it can push the pusher blade 1223 and thus drive the rotating body 122 to rotate. The nitrogen injection port 130 can be as follows: Figure 7 They can be arranged in a row on the same side wall, or they can be arranged on the side walls of two different sides. Taking three nitrogen injection ports 130 as an example, the highest and lowest nitrogen injection ports 130 can be arranged on the same side wall, and the middle nitrogen injection port 130 can be arranged on the other side wall. However, it should be noted that all nitrogen injection ports 130 blow the rotating body 122 in the same direction. In this case, the tilting nozzle 1221 does not need to be tilted.

[0079] Whether nitrogen or isopropanol is supplied to drive the rotating body 122, no additional power components are required. There is no need for external drive components such as motors, nor for a drive shaft passing through the housing 100. The housing 100 lacks a dynamic seal structure, fundamentally avoiding the risk of wafer contamination from wear-induced particles from dynamic seals, and also preventing the safety hazard of isopropanol leakage from dynamic seals. Furthermore, the rotational speed of the rotating body 122 automatically changes with the injection pressure of isopropanol or nitrogen, requiring no additional control components and eliminating the need for separate energy consumption for stirring. The structure is simple and the operation is reliable.

[0080] The fixed shaft 230 is provided with several flow ports 231. When isopropanol is injected from the isopropanol injection port 120, it flows through the hollow part of the fixed shaft 230 and the flow ports 231 into the gap space 232 between the outer wall of the fixed shaft 230 and the hollow space 1220 of the rotating body 122, and then is ejected through the inclined nozzle 1221. The fixed shaft 230 and the rotating body 122 have certain sealing structures at the top and bottom, but these sealing structures do not need to be completely sealed. The fixed shaft 230 is located at the center of the inner bearing plate 210.

[0081] The rotating body 122 is made entirely of PTFE (polytetrafluoroethylene) or other similar materials and has self-lubricating properties.

[0082] If necessary, the rotating body 122 can be equipped with both an inclined nozzle 1221 and a pusher blade 1223 to improve the rotation effect. In this case, the position of the nitrogen injection port 130 aligned with the pusher blade 1223 should ensure that the direction of the rotational force applied by the nitrogen injection port 130 to the rotating body is the same as the direction of the rotational force applied by the inclined nozzle 1221 when spraying isopropanol liquid. The presence of the pusher blade 1223 can also quickly disperse the nitrogen gas introduced through the nitrogen injection port 130, improving the mixing efficiency.

[0083] Setting multiple nitrogen injection ports 130 in different areas can increase the contact between nitrogen and isopropanol, improve mixing efficiency, and the introduction of nitrogen can continuously increase the pressure inside the outer shell 100, promoting the outflow of the nitrogen and isopropanol mixture.

[0084] It is worth noting that all interfaces, such as the isopropanol injection port 120, nitrogen injection port 130, and mixed gas output port 101, are connected to pipelines and can be equipped with valves to control their on / off state. The circulation of isopropanol outside the wafer drying gas mixing device is prior art and will not be elaborated here. Typically, the mixed gas is continuously circulated for a period of time before being supplied externally to ensure uniform mixing. Nitrogen needs to be heated before entering the nitrogen injection port 130. The nitrogen and isopropanol mixture flows out from the mixed gas output port 101 and is transported to the drying device used for drying the wafer. A vent can also be provided at the bottom of the outer casing 100 to drain liquid from the outer casing 100 when necessary.

[0085] In addition to temperature sensors, various sensor interfaces can be provided on the housing 100 to detect various physicochemical parameters inside the housing 100, such as pressure, viscosity, density, and concentration.

[0086] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "side," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing the technical solution of this application, 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, and therefore should not be construed as a limitation on the technical solution of this application. Furthermore, the terms "first," "second," etc., 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. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

Claims

1. A wafer drying gas mixing device, characterized in that, include: The outer casing (100) has a mixing chamber (140) inside. The top of the outer shell (100) is provided with an isopropanol injection port (120), which is connected to the mixing chamber (140) and is used to supply isopropanol liquid to the mixing chamber (140); The outer casing (100) is also provided with a nitrogen injection port (130) and a mixed gas output port (101). The nitrogen injection port (130) is used to inject heated nitrogen into the mixing chamber (140), and the mixed gas output port (101) is used to discharge the mixed gas in the mixing chamber (140). At least one inner support plate (210) is provided in the mixing chamber (140). A vertically arranged fixed shaft (230) is provided in the mixing chamber (140). A rotating body (122) is sleeved on the fixed shaft (230). One end of the fixed shaft (230) is fixed to the top of the outer shell (100) to form an isopropanol injection port (120). The rotating body (122) can rotate when nitrogen and / or isopropanol are supplied. A stirring blade (1222) is provided on the rotating body (122). When the rotating body (122) rotates, the stirring blade (1222) can stir the isopropanol liquid located around the rotating body (122) on the inner support plate (210).

2. The wafer drying gas mixing apparatus according to claim 1, characterized in that, The rotating body (122) is provided with an inclined nozzle (1221). When the inclined nozzle (1221) sprays isopropanol, it can drive the rotating body (122) to rotate.

3. The wafer drying gas mixing apparatus according to claim 2, characterized in that, The inclined nozzles (1221) are several that are inclined in the same direction.

4. The wafer drying gas mixing apparatus according to any one of claims 1-3, characterized in that, The rotating body (122) is provided with a pusher blade (1223), and the nitrogen injection port (130) is provided on the side wall of the outer shell (100). The nitrogen injection port (130) is aligned with the pusher blade (1223). When nitrogen is injected into the mixing chamber (140) along the nitrogen injection port (130), it can push the pusher blade (1223) and thus push the rotating body (122) to rotate.

5. The wafer drying gas mixing apparatus according to claim 2, characterized in that, The fixed shaft (230) is provided with a plurality of flow ports (231). When isopropanol is injected from the isopropanol injection port (120), it flows through the hollow part of the fixed shaft (230) and the flow ports (231) into the gap space (232) between the outer wall of the fixed shaft (230) and the rotating body (122), and then is ejected through the inclined nozzle (1221).

6. The wafer drying gas mixing apparatus according to claim 1, characterized in that, The inner support plate (210) is provided with annular overflow teeth (211). When the isopropanol liquid fills the space inside the overflow teeth (211), the isopropanol liquid will flow out from the gap between the overflow teeth (211) to the area outside the overflow teeth (211) on the inner support plate (210).

7. The wafer drying gas mixing apparatus according to claim 6, characterized in that, The inner support plate (210) is provided with guide plates (220) on both sides. The inner support plate (210) without guide plates (220) is provided with baffles (212) on both sides. Isopropanol flowing to the area outside the overflow teeth (211) on the inner support plate (210) can flow through the through holes (221) of the guide plate (220) to the outside of the guide plate (220) and flow down along the outer wall of the guide plate (220).

8. The wafer drying gas mixing apparatus according to claim 7, characterized in that, The bottom of the deflector plate (220) has a bend (222) that curves toward the center of the outer shell (100).

9. The wafer drying gas mixing apparatus according to claim 1, characterized in that, The fixed shaft (230) is located in the middle of the bearing inner plate (210).

10. The wafer drying gas mixing apparatus according to claim 1, characterized in that, The rotating body (122) is made of a self-lubricating material.

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