Wafer drying device

Abstract

The utility model provides a wafer drying device. The wafer drying device comprises a groove body, a placing platform, a drying platform, an external air source and a wafer boat. The external gas source is connected to the drying platform and used for providing drying gas. The wafer boat is used for bearing a plurality of wafers. The wafer boat is placed on the placing platform, and the bottom ends of the plurality of wafers abut against the drying platform, so that liquid attached to the bottom ends of the plurality of wafers is removed through drying gas provided by an external gas source.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor manufacturing, and in particular, to a wafer drying device. BACKGROUND

[0002] In semiconductor processes, wafer drying is a crucial step that directly affects process yield and final product quality. The effectiveness of drying not only determines the cleanliness of the wafer surface but also affects the stability and reliability of subsequent processes. However, current drying techniques still have some bottlenecks that affect process efficiency and quality control.

[0003] For example, the traditional hot nitrogen drying technique usually includes three main steps. First, during the wafer cleaning stage, the wafer and boat are immersed in deionized water for cleaning to remove particles and chemical residues. Then, in the draining stage, deionized water is drained through the bottom of the tank to gradually separate the wafer from the liquid surface. Finally, in the drying process, hot nitrogen gas jets are used to blow the wafer surface to remove residual moisture. However, this technique has obvious bottlenecks and problems. Although hot nitrogen blowing can effectively evaporate the moisture on the wafer surface, water droplets may still remain on the bottom of the wafer, which cannot be completely dried. This residual moisture can have a series of negative effects on the process, including reduced process yield and degraded surface quality. The presence of water droplets can cause contamination, further affecting the stability of subsequent processes. In addition, non-uniform evaporation of water droplets can cause water marks or drying spots, resulting in a decrease in wafer surface quality and even affecting the electrical properties and reliability of the components.

[0004] Therefore, it is necessary to provide a wafer drying device to solve the above technical problems. SUMMARY

[0005] To solve the above problems of the prior art, the purpose of the present application is to provide a wafer drying device that can achieve comprehensive drying of the bottom of the wafer.

[0006] In a first aspect, the present application provides a wafer drying device, comprising: a tank having a bottom wall, a plurality of side walls, and an opening, wherein the plurality of side walls surround the bottom wall, and the opening is provided above the tank; a placement platform and a drying platform provided close to the bottom wall; an external gas source connected to the drying platform for providing drying gas; and a boat for carrying a plurality of wafers, wherein the boat enters the tank through the opening and is placed on the placement platform, and the bottom ends of the plurality of wafers rest on the drying platform to remove liquid attached to the bottom ends of the plurality of wafers by the drying gas provided by the external gas source.

[0007] In some embodiments, the drying platform comprises: an elongated bar extending along the arrangement direction of the plurality of wafers; an elongated groove formed on the surface of the elongated bar in contact with the plurality of wafers; and a gas channel in communication with the elongated groove and connected to the external gas source, wherein the drying gas provided by the external gas source is introduced into the elongated groove through the gas channel and applied to the bottom end of the plurality of wafers to remove the liquid.

[0008] In some embodiments, the external gas source provides the drying gas with negative pressure.

[0009] In some embodiments, the external gas source provides the drying gas with positive pressure.

[0010] In some embodiments, the wafer drying device further comprises a plurality of air jet devices arranged on the plurality of side walls, and the outlets of the plurality of air jet devices are aligned with the plurality of wafers.

[0011] Compared with the prior art, the present application introduces a drying platform, so that the bottom end of the wafer is in contact with the drying platform and uniformly releases hot nitrogen gas at a controlled temperature, ensuring that the airflow can fully cover the bottom of the wafer. This design not only effectively improves the drying uniformity and avoids the problem of uneven local drying, but also accelerates the volatilization and removal of residual moisture at the bottom. BRIEF DESCRIPTION OF DRAWINGS

[0012] The technical solutions and other beneficial effects of the present application will become apparent through the detailed description of the specific embodiments of the present application in combination with the accompanying drawings.

[0013] Figure 1 A schematic diagram of a wafer drying device according to an embodiment of the present application is shown.

[0014] Figure 2 A perspective view of the wafer drying device according to Figure 1

[0015] Figure 3 A partial schematic view of a groove according to an embodiment of the present application is shown.

[0016] Figure 4 A first operation view of a drying platform according to an embodiment of the present application is shown.

[0017] Figure 5 A second operation view of a drying platform according to an embodiment of the present application is shown.

[0018] Figure 6 A flowchart of an operation method of a wafer drying device according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0019] ​The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0020] In semiconductor processes, wafer drying is a crucial step that directly impacts the process yield and the quality of the final product. The effectiveness of wafer drying not only relates to the cleanliness of the wafer surface but also profoundly affects the stability and reliability of subsequent processes. Incomplete drying, especially the failure to completely remove water droplets from the bottom of the wafer, can cause process contamination, leading to wafer surface defects or unstable electronic component performance, ultimately affecting the overall yield. Therefore, achieving precise and efficient drying technology is crucial for ensuring the high quality of semiconductor products. In view of the problem in the prior art that water droplets at the bottom of the wafer are difficult to completely remove, the present application proposes an innovative wafer drying device to solve this technical bottleneck, as described below.

[0021] Please refer to Figure 1 and Figure 2 , Figure 1 show the schematic diagram of the wafer drying device of the embodiments of the present application, and Figure 2 show Figure 1 the perspective view of the wafer drying device. The wafer drying device 10 includes a tank body 100, a fixing frame 200, a placement platform 300, a drying platform 400, a wafer boat 500, a plurality of air jet devices 600, and an external gas source. The wafer drying device 10 of the present application belongs to a batch type wafer wet process equipment, mainly designed for batch cleaning and drying of multiple wafers. The device can process multiple wafers at the same time, improve process efficiency, and ensure that each wafer can achieve high cleanliness and high uniformity of drying effect. It is suitable for various cleaning and drying steps in the semiconductor manufacturing process, especially suitable for high-capacity processes, which can effectively reduce the time cost of single processing, improve production efficiency, and ensure the stability of subsequent processes and product yield.

[0022] As shown in Figure 1 and Figure 2 , the tank body 100 mainly consists of a bottom wall 101, a plurality of side walls 102, and an opening 103. The structural design aims to provide a stable processing space for wafer cleaning and drying operations. The side walls 102 surround the bottom wall 101 to form a containing space inside the tank body 100, allowing the wafer and the processing liquid to be effectively controlled inside the tank. In addition, the opening 103 is arranged above the tank body 100 and corresponds to the bottom wall 101, which facilitates the entry and exit of the wafer boat together with the wafers.

[0023] As shown in Figure 1 and Figure 2 The fixed frame 200 is arranged on the bottom wall 101 of the tank body 100 and located inside the tank body 100 to provide a stable support structure for the placement platform 300 and the drying platform 400. Specifically, the fixed frame 200 is composed of a plurality of bases and a plurality of long rods, wherein the bases are fixedly installed on the bottom wall 101 of the tank body 100 correspondingly, and the long rods are arranged in a staggered manner in the horizontal or vertical direction and fixed to the corresponding bases or directly fixed to the bottom wall 101 to form a stable frame-shaped structure. This frame-shaped structure not only provides high-strength support, enabling the placement platform 300 and the drying platform 400 to be stably erected in the appropriate position, i.e., arranged near the bottom wall 101 of the tank body 100, but also ensures that they maintain appropriate spacing from the bottom wall 101 to optimize air circulation and improve drying efficiency and uniformity. In addition, the design of the fixed frame 200 has high modularity and adjustment flexibility, which can be adapted to different batch requirements and wafer sizes, ensuring that the device can be applied to various semiconductor processes and improving the adaptability and operating efficiency of the overall drying system.

[0024] As shown in Figure 1 and Figure 2 The wafer boat 500 is designed to carry a plurality of wafers W, enabling them to undergo simultaneous cleaning and drying processes. To improve process efficiency, the wafer boat 500 has the ability to move relative to the tank body 100 and can achieve precise positioning through a moving mechanism. Specifically, the moving mechanism can drive the wafer boat 500 into the interior of the tank body 100 and can also take it out of the tank body 100 after the process is completed, ensuring that the wafers W can stably and smoothly undergo each stage of the process. When the wafer boat 500 enters the tank body 100, it will enter through the opening 103 and be placed on the placement platform 300, so that the bottom end of the wafer W is in contact with the drying platform 400, facilitating the drying process. Further, in some embodiments, the drying platform 400 can slightly lift the wafer W, enabling its bottom to be fully exposed to the airflow environment, avoiding the obstruction of the wafer boat 500's internal structure to the airflow. In this way, the uniformity and efficiency of the airflow contacting the bottom of the wafer can be greatly improved, promoting rapid evaporation of moisture, thereby improving the drying effect, reducing the impact of residual water droplets on subsequent processes, and ensuring the quality of the wafer surface and process yield.

[0025] As shown in Figure 1 and Figure 2As shown, the air jet devices 600 serve as the core drying mechanism inside the tank 100, mainly for rapidly removing most of the residual liquid on the surface of the wafers W to ensure the efficiency and uniformity of the drying process. The plurality of air jet devices 600 are arranged on the sidewalls 102 of the tank 100 and inside the tank 100 to ensure that the airflow can directly act on the surface of the wafers W. In this embodiment, four groups of air jet devices 600 are arranged inside the tank 100, respectively installed on the corresponding two sidewalls 102 to achieve full coverage of the airflow on the wafers W. Each group of air jet devices 600 includes a plurality of gas outlets distributed along the arrangement direction of the wafers W, which are precisely aligned with the wafers W so that the airflow can be effectively applied to the wafer surface. When the drying process starts, the air jet devices 600 release high-speed airflow and generate an inclined downward airflow with a specific direction to drive the liquid on the surface of the wafers W to flow in a specific direction, so that it quickly separates from the surface of the wafers W. In addition, the airflow not only effectively reduces the amount of residual liquid on the wafer surface, but also promotes the uniform discharge of the liquid, further reducing the risk of water marks, uneven drying or particle contamination. Through the design and arrangement of the air jet devices, the efficiency and reliability of wafer drying can be significantly improved to ensure the stability and high yield of subsequent processes.

[0026] Please refer to Figure 3 , which shows a partial schematic view of the tank of the embodiment of the present application. The drying platform 400 is designed to improve the drying efficiency of the bottom of the wafers W, which mainly includes an elongated rod 401, an elongated groove 402 and a gas channel 403. The elongated rod 401 extends along the arrangement direction of the plurality of wafers W to ensure that the bottom of all wafers W can stably contact the drying platform 400 to achieve uniform airflow distribution and drying effect. When the wafer boat 500 enters the tank 100 and is placed on the placement platform 300, the bottom end of each wafer W will abut against the elongated rod 401 to ensure that the drying gas can directly act on the bottom of the wafer. In order to further improve the drying effect, the elongated rod 401 is provided with an elongated groove 402 on the surface in contact with the wafer W, so that it forms an airflow guiding area with the bottom of the wafer W. The gas channel 403 is in communication with the elongated groove 402 and connected to an external gas source to provide stable and controlled drying gas, such as hot nitrogen or other suitable inert gas, during the drying step. When the drying process starts, the drying gas supplied by the external gas source is introduced into the elongated groove 402 through the gas channel 403 and uniformly applied to the bottom end of the wafer W to effectively remove the residual liquid. Through such design, not only the evaporation of water can be accelerated, but also the risk of water marks or uneven drying can be reduced, further improving the quality of the wafer surface and the process yield.

[0027] Please refer to Figure 4, which shows the first operation view of the drying platform of the embodiment. In some embodiments, the external gas source provides drying gas with negative pressure to optimize the liquid removal efficiency at the bottom end of the wafer W. When the drying process is started, the negative pressure environment generated by the external gas source can form a local low pressure area near the drying platform 400, and through the action of air flow driving and pressure difference, it can promote the liquid attached to the bottom end of the wafer W to quickly separate from the surface. Specifically, the negative pressure drying mechanism can effectively reduce the surface tension of the liquid through the effect of air suction, so that the liquid droplets remaining on the bottom end of the wafer W are more easily evaporated or carried away by the air flow. In addition, the mechanism can also reduce the drying spots, water marks or contaminant accumulation caused by liquid residue, further improving the cleanliness and drying uniformity of the wafer surface. This negative pressure drying technology can be used alone or combined with other air flow guiding mechanisms (such as the downward air flow provided by the air jet device 600) to achieve more efficient wafer drying effect and ensure the stability and high yield of subsequent processes.

[0028] Please refer to Figure 5 , which shows the second operation view of the drying platform of the embodiment. In some embodiments, the external gas source provides drying gas with positive pressure to enhance the blowing effect of the air flow and accelerate the liquid removal at the bottom end of the wafer. When the drying process is started, the positive pressure drying gas generated by the external gas source is introduced into the elongated groove 402 through the gas channel 403, and is uniformly released to the bottom end of the wafer from the surface of the elongated rod 401. Through the blowing effect of the high pressure air flow, the surface tension of the liquid can be effectively destroyed, so that the liquid droplets remaining on the bottom end of the wafer quickly move and separate from the surface. In addition, the air flow can further promote the evaporation of the liquid, reduce the risk of water stain residue, and ensure the cleanliness and drying uniformity of the wafer surface. In some applications, the positive pressure drying gas can work together with the downward air flow generated by the air jet device 600 to make the air flow direction consistent with the liquid discharge direction, further improving the drying efficiency. In addition, the drying technology can adjust the gas pressure and flow according to different process requirements to adapt to different types of wafer sizes and wet process conditions, improving the applicability and flexibility of the drying device.

[0029] The application also provides an operation method of a wafer drying device, wherein the structure of the wafer drying device is as described above, which will not be repeated here. It should be understood that the wafer drying device 10 can further include a host computer in addition to the above structure. The host computer is in communication connection with each element of the wafer drying device 10, and includes an electrically connected processor and a memory. The processor and the memory of the host computer are arranged on a circuit board. The memory is configured to store executable program codes. The processor runs programs corresponding to the executable program codes by reading the executable program codes stored in the memory, to perform the operation method of the wafer drying device of the application.

[0030] In this embodiment, the processor is generally configured to control the overall operation of the host. The processor can include one or more processors to execute instructions to perform actions in all or part of the steps in the operation of the wafer drying apparatus 10 described above. In addition, the processor can include one or more modules to facilitate interaction between the processor and other components. For example, the processor can include a communication module to facilitate interaction between the communication component and the processor. The memory is configured to store various types of data to support the operation of the host. Examples of such data include instructions for any application or method operating on the host. The memory can be implemented using any type of volatile or non-volatile memory device or a combination thereof. The power supply circuit supplies power to various components of the host. The power supply circuit can include a power management system, one or more power supplies, and any other components associated with the generation, management, and distribution of power to the host. In an exemplary embodiment, the host can be implemented by a standalone terminal device or an electronic component such as a controller, microcontroller, etc. integrated in the wafer drying apparatus 10.

[0031] Please refer to Figure 6 , which shows a flowchart of the operation method of the wafer drying apparatus according to an embodiment of the present application. The operation method of the wafer drying apparatus according to the present application includes: first, in step S61, providing a wafer drying apparatus 10 as described above. As shown in Figure 1 , the wafer drying apparatus 10 includes a tank body 100, a fixing frame 200, a placement platform 300, a drying platform 400, a wafer boat 500, a plurality of air jet devices 600, and an external air source. The structure of the plurality of and the remaining additional elements is as described above, and will not be repeated here.

[0032] As shown in Figure 1 , in step S62, the wafer boat 500 carrying the plurality of wafers W is moved into the tank body 100 through the opening 103 of the tank body 100 and placed on the placement platform 300, wherein the bottom end of the plurality of wafers W abuts against the drying platform 400. Specifically, in some embodiments, the wafer boat 500 is moved into the interior of the tank body 100 by a moving mechanism and stably placed on the placement platform 300. At this time, the bottom end of each wafer W abuts against the drying platform 400, so that it is in full contact with the drying mechanism to facilitate subsequent drying processing. In some embodiments, the drying platform 400 can cause the bottom end of the wafer W to be moderately lifted, ensuring that the airflow can uniformly act on the bottom area, avoiding the shielding effect that the wafer boat 500 can cause. In addition, the placement position of the wafer boat 500 can be adjusted according to different wafer sizes and batch requirements to ensure the best drying effect, further improving the process yield and wafer surface quality.

[0033] In step S63, liquid is injected into the tank 100 to immerse the plurality of wafers W therein. Optionally, the liquid is deionized water (DI water) for cleaning the wafer surface to remove residual contaminants, particles or chemical agents, ensuring the effectiveness of the subsequent drying process. In the present embodiment, when the liquid is injected into the tank 100, the wafer boat 500 together with the wafers W carried thereby is completely immersed in the liquid, so that the liquid uniformly covers the wafer surface to improve the cleaning effect. In some applications, an ultrasonic or bubble agitation mechanism can be used to improve the efficiency of removing particles and chemical residues. In addition, the flow rate, temperature and cleaning time of the liquid can be adjusted according to different process requirements to ensure the best cleaning effect, thereby improving the stability and reliability of the wafer process.

[0034] In step S64, the liquid is drained. Specifically, the bottom wall 101 of the tank 100 is provided with a drain. The liquid is gradually drained through the drain at the bottom of the tank 100 to achieve a controlled drainage process. Generally, the liquid discharge process needs to be precisely controlled to prevent the liquid level from dropping rapidly, thereby avoiding water stains caused by uneven water marks or surface tension effects. To further optimize the drainage effect, a phased drainage strategy can be used, i.e. a large part of the liquid is discharged at a faster speed in the initial stage, and then the drainage speed is slowed down to gradually remove the liquid from the wafer surface uniformly, reducing the risk of residual water droplets.

[0035] In some embodiments, while the liquid is being drained, an inert gas (such as nitrogen) can be introduced simultaneously to assist the airflow to accelerate the evaporation of the liquid and ensure that the wafer surface remains uniformly dry during the drainage process, further improving the drying effect and process stability. Specifically, the gas injection device 600 arranged above the tank 100 can be activated to blow hot nitrogen gas of a controlled temperature from the left and right sides above the wafers to the wafer surface through the gas outlets thereof. The airflow can effectively reduce the surface tension effect, promote the rupture of the liquid film and the evaporation of the water, and prevent the liquid from re-aggregating on the wafer surface, thereby avoiding the formation of water stains or drying marks. In addition, by adjusting the injection angle and flow rate of the gas injection device 600, the airflow distribution can be further optimized to uniformly cover the wafer surface with hot nitrogen gas, ensuring that each wafer can achieve the desired preliminary drying effect, laying a foundation for the subsequent more delicate drying steps. To further improve the drying uniformity, the airflow guiding mechanism and the blowing flow rate can be dynamically adjusted according to the size and arrangement density of the wafers, so that the hot nitrogen gas can penetrate into the gaps between the wafers to effectively eliminate possible drying dead angles, ensuring that the entire batch of wafers can achieve the best drying effect, thereby improving the process stability and product yield.

[0036] In step S65, the liquid adhering to the bottom of the wafer is removed by drying gas supplied from an external gas source. Specifically, the drying platform 400, located below the tank 100, is activated, allowing it to uniformly release hot nitrogen gas at a controlled temperature through its internally configured gas channels 403 and elongated grooves 402. The hot nitrogen gas flows parallel to the bottom of the wafer, forming a stable and uniform airflow layer, effectively reducing the influence of surface tension, promoting water droplet breakage and evaporation, and thus accelerating the drying process. Furthermore, by adjusting the gas flow rate and temperature of the drying platform 400, sufficient airflow coverage can be ensured at the bottom of the wafer, avoiding uneven drying in certain areas and further improving drying efficiency and process stability. In some embodiments, the drying platform 400 can also be designed to appropriately lift the wafer, fully exposing its bottom to the airflow environment, reducing the impact of the crystal boat 500's structural obstruction on airflow distribution and further optimizing the drying effect.

[0037] like Figure 4 As shown, in some embodiments, an external air source provides drying gas with negative pressure to optimize liquid removal efficiency at the bottom of wafer W. When the drying process starts, the negative pressure environment generated by the external air source can form a local low-pressure zone near the drying platform 400. Through airflow drive and pressure difference, the liquid adhering to the bottom of wafer W is quickly detached from the surface. Specifically, the negative pressure drying mechanism can effectively reduce the surface tension of the liquid through suction, making it easier for droplets remaining at the bottom of wafer W to evaporate or be carried away by the airflow. In addition, the mechanism can also reduce drying spots, watermarks, or contaminant accumulation caused by liquid residue, further improving the cleanliness and drying uniformity of the wafer surface. This negative pressure drying technology can be used alone or in combination with other airflow guidance mechanisms (such as the downward airflow provided by the jet device 600) to achieve a more efficient wafer drying effect, ensuring the stability and high yield of subsequent processes.

[0038] like Figure 5As shown, in some embodiments, an external gas source provides dry gas with positive pressure to enhance the blowing effect of the gas flow and accelerate the liquid removal at the bottom end of the wafer. When the drying process is initiated, the dry gas with positive pressure generated by the external gas source is introduced into the elongated groove 402 through the gas channel 403 and uniformly released from the surface of the elongated rod 401 to the bottom end of the wafer. Through the blowing effect of the high-pressure gas flow, the surface tension of the liquid can be effectively broken, so that the liquid droplets remaining at the bottom end of the wafer can quickly move and separate from the surface. In addition, the gas flow can further promote the evaporation of the liquid, reduce the risk of water stain residue, and ensure the cleanliness and uniformity of the wafer surface. In some applications, the positive pressure dry gas can work with the downward gas flow generated by the air jet device 600 to make the gas flow direction consistent with the liquid discharge direction, further improving the drying efficiency. In addition, the drying technology can adjust the gas pressure and flow according to different process requirements to adapt to different types of wafer sizes and wet process conditions, improving the applicability and flexibility of the drying device.

[0039] In summary, the present application provides a wafer drying device that achieves comprehensive drying of the bottom of the wafer by introducing a drying platform. Specifically, the drying platform can properly lift the wafer slightly to expose the bottom of the wafer to the gas flow environment, thereby promoting the evaporation and removal of moisture. The main gas flow guide system composed of the air jet device precisely controls the distribution and flow rate of the drying gas through directional gas flow, ensuring that each area of the wafer can be uniformly heated and moisture removed.

[0040] The above provides a detailed description of a wafer drying device provided by the embodiments of the present application. The principles and implementation methods of the present application are described in this paper using specific embodiments. The above description of the embodiments is only used to help understand the technical solutions and core ideas of the present application. Those skilled in the art should understand that the technical solutions described in the above embodiments can be modified or some technical features can be replaced by equivalents. These modifications or replacements do not change the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A wafer drying apparatus, characterized in that, include: A tank having a bottom wall, multiple side walls and an opening, wherein the multiple side walls surround the bottom wall and the opening is located above the tank. The placement platform and drying platform are located near the bottom wall; An external gas source is connected to the drying platform to provide drying gas; as well as A crystal boat is used to carry multiple wafers, wherein the crystal boat enters the tank through the opening and is placed on the placement platform, and the bottom ends of the multiple wafers abut against the drying platform to remove liquid adhering to the bottom ends of the multiple wafers by the drying gas provided by the external gas source.

2. The wafer drying apparatus as described in claim 1, characterized in that, The drying platform includes: An elongated rod extends along the arrangement direction of the plurality of wafers; An elongated groove is formed on the surface of the elongated rod that contacts the plurality of wafers; and A gas channel communicates with the elongated groove and is connected to the external gas source, wherein the drying gas provided by the external gas source is introduced into the elongated groove through the gas channel and applied to the bottom of the plurality of wafers to remove the liquid.

3. The wafer drying apparatus as described in claim 1, characterized in that, The external gas source provides the dry gas with negative pressure.

4. The wafer drying apparatus as described in claim 1, characterized in that, The external gas source provides the dry gas with positive pressure.

5. The wafer drying apparatus as described in claim 1, characterized in that, The wafer drying apparatus also includes multiple jet devices disposed on the multiple sidewalls, and the outlets of the multiple jet devices are aligned with the multiple wafers.

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