A drying trough structure for optimizing the Marangoni drying flow field of a swinging type

Abstract

The present invention relates to a drying tank structure for optimizing the Marangoni drying flow field of a swinging type, and the drying tank structure includes a main tank, which is a funnel-shaped main structure with a gentle slope for liquid discharge; a sunken channel, located at the center of the bottom of the main tank, and provided with a discharge hole at the lowest end of its slope; overflow tanks, respectively arranged on both sides of the main tank for discharging overflowed ultrapure water and isopropyl alcohol; a negative pressure chamber, arranged in the overflow tank to form a negative pressure exhaust air chamber; an injection water pipeline, arranged in the sunken channel, and provided with an injection pipe discharge hole on it. The drying tank structure of the present invention can achieve uniform infiltration of ultrapure water on both sides of a batch of wafers, and form a vertical downstream traction to avoid the generation of disordered flow-around. The negative pressure exhaust air chamber is used to ensure uniform distribution of IPA mist in the tank, and external air will not enter the chamber to contaminate the wafers.

Description

Technical Field

[0001] The present invention relates to semiconductor processing equipment, and particularly to a drying tank structure for optimizing the Marangoni drying flow field of a swing type. Background Art

[0002] After the wafer is completed with circuit etching, wafer drying is the last action in the wet cleaning process, which requires ensuring the effective removal of residual moisture on the wafer surface and controlling its surface cleanliness. Under the goal of continuously optimizing the drying method to improve the drying efficiency, the development of wafer cleaning equipment and technology requires special attention to the drying work of the wafer. In the prior art, there are various methods used in the wafer drying process, and IPA replacement drying or Marangoni drying is a common technical means. In IPA replacement drying or Marangoni drying, a fluid medium (liquids such as ultrapure water, isopropyl alcohol, gases such as nitrogen, isopropyl alcohol) needs to be used and flows in the drying tank under various fluid usage conditions. Therefore, the design and control of the flow field are of great technical significance for solving problems such as water mark problems or particle residues in wafer drying.

[0003] In the drying tank, the input and discharge of liquids and gases need to wet or cover the wafer. During the drying process, the discharge of gases and liquids affects the ability of the wafer to dry and remove residual moisture on the surface. Therefore, a method needs to be found to effectively improve the flow of the fluid when the wafer is dried, making its dynamic process smoother. The technical solution of this invention patent is to add a structure in the drying tank that enhances fluid flow with a drainage design to solve the above water mark problem and particle residue problem. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art that the drying method is not optimized enough and the drying efficiency is low, and to provide a drying tank structure for optimizing the Marangoni drying flow field of a swing type. The drying tank structure of the present invention should be able to avoid generating turbulent flow when the liquid is filled from above or discharged from below, so that the liquid can flow smoothly to achieve the cleaning of the wafer, and assist in solving the problems of liquid accumulation residue and uneven cleaning caused by the liquid fluctuation position during wafer drying through the smooth flow of the liquid in the drying tank.

[0005] In order to achieve the above invention purpose, the technical solution provided by this invention patent is as follows:

[0006] The present invention provides a drying tank structure for optimizing the Marangoni drying flow field of a swing type, and the drying tank structure includes: a main tank and an overflow tank

[0007] The main tank is a funnel-shaped main structure with a gentle slope for liquid discharge, and includes:

[0008] The sunken channel is located at the bottom center of the main channel and has an inclined slope. A discharge hole is provided at the lowest end of the slope.

[0009] The injection water pipeline is arranged in the sunken channel, and an injection pipe discharge hole is provided on the injection water pipeline.

[0010] The overflow channels are arranged on both sides of the main channel to discharge the overflowed ultrapure water and isopropyl alcohol residue liquid, and include:

[0011] The overflow liquid inlet chamber is arranged in the overflow channel on one side, is connected to the external ultrapure water pipeline through the overflow liquid inlet pipe, is connected to the main channel through the overflow liquid inlet hole, and injects ultrapure water into the main channel in the horizontal direction.

[0012] The negative pressure chamber is arranged outside the overflow channel and forms a negative pressure exhaust air cavity by guiding the gas to be discharged through the air outlet.

[0013] In the drying tank body structure of an optimized swing-type Marangoni drying flow field according to the present invention, the injection pipe discharge holes on the injection water pipeline are straight array holes that expand upward and to both sides. Each hole on the straight array holes corresponds to the center distance between wafers. With this design, the liquid can effectively correspond to the position of each wafer during injection, ensuring that each wafer can be evenly wetted while the ultrapure water is injected, and each position on the front and back sides of the batch of wafers can be wetted by the ultrapure water.

[0014] In the drying tank body structure of an optimized swing-type Marangoni drying flow field according to the present invention, as an optimized design, the distance between adjacent straight array holes below the wafer position is equal to the distance between adjacent wafers, and the distance between adjacent straight array holes at the positions on both sides below the wafer is greater than the distance between adjacent wafers. The purpose of this design is on the one hand to fully wet the wafers, and on the other hand to avoid the disturbance flow caused by the too-close distance of the ultrapure water ejected from both sides.

[0015] In the drying tank body structure of an optimized swing-type Marangoni drying flow field according to the present invention, a blind plate is provided on the upper part of the overflow channel with an overflow liquid inlet chamber on one side of the main channel, and a drainage channel formed by a guide plate corresponding to the liquid overflow area is provided on the overflow channel on the other side.

[0016] In the drying tank body structure of an optimized swing-type Marangoni drying flow field according to the present invention, as an optimized design, the drainage channel is an inclined knife-type drainage ramp above the overflow channel, and the bottom of the inclined knife-type drainage ramp is aligned with the upper part of the negative pressure chamber.

[0017] In the drying tank body structure of an optimized swing-type Marangoni drying flow field according to the present invention, as an optimized design, the negative pressure chamber and the overflow channel are separated by a wall plate, an exhaust hole is provided in the upper part of the wall plate to connect the negative pressure chamber and the overflow channel, and the bottom of the guide plate is opposite to the position of the exhaust hole.

[0018] In the drying tank body structure for optimizing the Marangoni drying flow field according to the present invention, a plurality of V-shaped notches for overflow are provided at positions near the overflow tank at the top of the main tank.

[0019] In the drying tank body structure for optimizing the Marangoni drying flow field according to the present invention, as an optimized design, the V-shaped notches are arranged in rows, and a row of the overflow liquid inlet holes is provided at the bottom of the V-shaped grooves on the side having the overflow liquid inlet cavity.

[0020] In the drying tank body structure for optimizing the Marangoni drying flow field according to the present invention, an overflow waste liquid discharge port is provided at the bottom of the overflow tank.

[0021] In the drying tank body structure for optimizing the Marangoni drying flow field according to the present invention, the negative pressure cavity is communicated, and an exhaust air cavity is provided at the rear of the main tank. The air outlet is provided at a position above the bottom of the exhaust air cavity, and an exhaust air waste liquid discharge port is provided at the bottom of the exhaust air cavity.

[0022] In the drying tank body structure for optimizing the Marangoni drying flow field according to the present invention, as an optimized design, a hole plate is further provided in the main tank. The hole plate is installed at a height of 1 / 4 from the bottom inside the main tank. The hole plate is provided above the discharge hole of the injection pipe and corresponds to the lower part of the wafer. During the process of liquid perfusion upward or discharge downward, under the action of the holes, the turbulent flow that may be generated is formed into a vertical downstream direction.

[0023] In the drying tank body structure for optimizing the Marangoni drying flow field according to the present invention, as an optimized design, the holes on the hole plate are arranged in a uniform array, and the diameter of the holes is 10 mm - 15 mm.

[0024] In the drying tank body structure for optimizing the Marangoni drying flow field according to the present invention, the discharge hole at the bottom of the sunken channel serves as a fast drainage interface, and a fast drainage valve is installed at the fast drainage interface. A slow drainage interface is provided on the inner side wall of the sunken channel, and a slow drainage valve is installed at the slow drainage interface. Through the double drainage valve design of the slow drainage valve and the fast drainage valve, when the liquid in the drying tank is at a high liquid level, slow drainage is adopted to avoid the liquid level fluctuation caused by the too fast drainage speed when the wafer is close to the liquid surface, resulting in liquid droplet contamination of the bottom of the wafer. After the liquid level drops to the middle liquid level, fast drainage is used to quickly empty the tank.

[0025] Based on the above technical solutions, compared with the prior art, the drying tank body structure for optimizing the Marangoni drying flow field according to the present invention has the following technical advantages:

[0026] 1. In the drying tank body structure of the present invention, the pipeline is designed with a direct drainage array of holes that diverge upward to both sides, and at the position corresponding to the wafer, the distance between each hole corresponds to the center distance between wafers, and at positions other than the corresponding wafer, the arrangement is with an enlarged distance. With this design, when the liquid is injected, it can effectively correspond to the position of each wafer, ensuring that when ultrapure water is injected into the wafer, both the front and back sides of the batch of wafers can be evenly wetted, and each position is evenly wetted with ultrapure water.

[0027] 2. The drying tank body of the present invention is specifically designed with a hole plate, which is installed at a position 1 / 4 of the height from the bottom of the main tank body and corresponds to the position below the wafer. The holes on the hole plate are evenly arranged in an array. When the liquid is poured upward or drained downward, the fluid can be pulled into a downstream flow, that is, under the action of the holes, the turbulent flow that may be generated is formed into a vertical downstream flow.

[0028] 3. During the drying process of the drying tank body of the present invention, the purpose of the overflow tank is to form a concentration gradient distribution of isopropyl alcohol from the middle to both sides in the main tank to better clean the wafer. The drying tank body is also specifically designed with an overflow liquid inlet cavity, so as to form a vertical jet flow at a position where the ultrapure water in the main tank is close to the top. The ultrapure water jet flows from the side with the blind plate to the side of the deflector, thereby interfering with the upward flow impact of the ultrapure water poured into the bottom to offset its impact force, making the cleaning more stable and controllable.

[0029] 4. In the present invention, a good flow field design can ensure that the isopropyl alcohol fog is evenly distributed in the cavity, and the air outside the tank body will not enter the cavity to contaminate the wafer. After the air flow path during the drying process moves from the main tank to the overflow tank direction, it is introduced into the negative pressure cavity area through the V-shaped notch structure on the overflow tank. The external atmospheric pressure is blocked by the inclined knife-type drainage ramp above in the small gap space. The gas in the drying tank body can, under the guiding action of the negative pressure cavity, be discharged to the pipeline together with the exhaust of the exhaust system. A self-sealing flow field is formed through the special structures of the negative pressure exhaust cavity and the deflector to ensure the tightness of the cavity.

[0030] 5. In the drying tank body structure of the present invention patent, a dual drainage valve design is adopted, that is, a fast drainage valve located at the bottom and a slow drainage valve located on the side wall are designed. The slow drainage valve is arranged close to the bottom. When the liquid level in the drying tank body is at a high level, the slow drainage valve is started to drain the liquid slowly, avoiding the phenomenon that the liquid level fluctuates violently when the drainage speed is too fast when the wafer is close to the liquid surface, resulting in liquid droplets contaminating the bottom of the wafer. When the liquid level drops to the middle level after the slow drainage method, the liquid separates from the wafer, and then the fast drainage valve can be opened to quickly empty the remaining liquid, improving the drying efficiency. Description of the Drawings

[0031] Figure 1It is the overall schematic diagram of the drying tank body structure for optimizing the Marangoni drying flow field of the present invention.

[0032] Figure 2 It is the schematic sectional view of the drying tank body structure for optimizing the Marangoni drying flow field of the present invention.

[0033] Figure 3 It is the three-dimensional schematic diagram of the main tank in the drying tank body structure for optimizing the Marangoni drying flow field of the present invention.

[0034] Figure 4 It is the three-dimensional schematic diagram of the main tank in the drying tank body structure for optimizing the Marangoni drying flow field of the present invention from another perspective.

[0035] Figure 5 It is the schematic diagram of the internal structure of the main tank in the drying tank body structure for optimizing the Marangoni drying flow field of the present invention.

[0036] Figure 6 It is the layout schematic diagram of the water inlet pipe in the tank in the drying tank body structure for optimizing the Marangoni drying flow field of the present invention.

[0037] Figure 7 It is the distribution schematic diagram of the V-shaped notch in the drying tank body structure for optimizing the Marangoni drying flow field of the present invention.

[0038] Figure 8 It is the schematic A-A sectional view in 7.

[0039] Figure 9 It is the enlarged schematic diagram of the baffle part in the drying tank body structure for optimizing the Marangoni drying flow field of the present invention.

[0040] Figure 10 It is the schematic diagram of the structure of the overflow liquid inlet cavity part in the drying tank body structure for optimizing the Marangoni drying flow field of the present invention.

[0041] Figure 11 It is the schematic diagram of the process of cleaning and drying the wafer in the drying tank body structure for optimizing the Marangoni drying flow field of the present invention.

[0042] Figure 12 It is the schematic diagram of the ultra-pure water flow direction when cleaning the wafer in the drying tank body structure for optimizing the Marangoni drying flow field of the present invention.

[0043] Among them, 1 - main body groove, 2 - opening and closing mechanism, 3 - drying chamber, 4 - wafer, 5 - separation bracket, 101 - overflow groove, 102 - overflow liquid inlet chamber, 103 - negative pressure chamber, 104 - ultrapure water tank, 105 - in-tank liquid inlet interface, 106 - fast drain interface, 107 - V-shaped notch, 108 - overflow liquid inlet hole, 109 - overflow liquid inlet pipe, 110 - hole plate, 111 - lower guide plate, 112 - blind plate, 113 - diversion plate, 114 - overflow waste liquid discharge port, 115 - tank support column, 116 - liquid level detection interface, 117 - exhaust waste liquid discharge port, 118 - air outlet, 119 - slow drain interface, 120 - injection water pipeline, 121 - upper exhaust hole, 122 - lower exhaust hole, 31 - spray pipe, 32 - upper guide plate Detailed implementation manners

[0044] Next, we will further elaborate on a drying tank structure for optimizing the Marangoni drying flow field of a swinging type in the present invention in combination with the attached drawings and specific embodiments, so as to more clearly understand its structural composition and working mode, but the protection scope of the present invention cannot be limited thereby.

[0045] When using a wet drying device to clean a wafer, for the cleaning and drying process of the wafer, it is necessary to infiltrate and dry the wafer, and the wafer is infiltrated and covered by controlling the input and discharge of liquid and gas, so as to achieve the purpose of thorough cleaning and drying. During the drying process, the discharge of gas and liquid will also affect the removal ability of the residual moisture on the wafer surface. The method of the present invention can effectively improve the flow field design in the drying tank structure during wafer drying, control and divert the fluid flow, make the entire cleaning and drying dynamic process smoother, have a better drying effect, and effectively solve the problems of water marks and particle residues on the wafer.

[0046] As Figure 1 and Figure 2 shown, the present invention provides a drying tank structure for optimizing the Marangoni drying flow field of a swinging type, which belongs to the core component of a wet drying device. As the core component for the wet cleaning process of a wafer, a chamber that can be opened and closed is formed by using the main body groove 1, the opening and closing mechanism 2, and the drying chamber 3, so as to realize the cleaning and drying operations of the wafer in the chamber. Among them, the cleaning work of the wafer is completed in the main body groove 1. An ultrapure water tank 104 is arranged inside the main body groove 1, and the wafer 4 is infiltrated and cleaned with ultrapure water. Then, a separation bracket is used to lift the wafer into the drying chamber 3, and the drying work is completed by using heated nitrogen and isopropyl alcohol IPA. The opening and closing mechanism 2 realizes the lateral opening and closing between the drying chamber 3 and the main body groove 1, so that the drying chamber 3 can move laterally under the drive of the opening and closing mechanism 2, and the main body groove 1 is opened to enable the wafer to change its internal and external positions before cleaning and after drying.

[0047] The core of the present invention lies in achieving a brand-new gas and liquid flow field design through a new structural design. Therefore, the drying tank body has been newly designed. As Figure 3 , Figure 4 and Figure 5 shown, the structure of the newly designed drying tank body mainly includes the following components:

[0048] The main tank 1, which is a funnel-shaped main structure with a gentle slope for liquid injection and discharge. At the center of the bottom of the main tank 1, there is a sunken channel, which also has an inclined slope. At the lowest end of the slope, there is a discharge hole, which is a fast drainage interface 106. By designing the sunken channel, it provides an overall speed-up effect for discharge. By adopting a construction method similar to a gentle slope-shaped funnel in the design and configuration of the drying tank body, corresponding to the placed wafers, it is placed at the central position in the opposite position, and a gentle descending slope is formed at the bottom of the drying tank body. The gentle descending slope corresponds to the power line to generate a smooth inclined descending flow line when the fluid moves downward. This flow line is arranged along the wafer and the gently descending slope-shaped tank body, and it can realize the downward and backward speed increase of the air flow power line along the discharge path. Subsequently, under the traction effect of the increased flow rate during the rapid downward discharge, it effectively returns to the wall edge of the exhaust position. At the bottom of the main tank 1, there are multiple tank support columns 115, which are convenient for fixing the main tank 1 on the wet cleaning equipment. Specifically, four tank support columns 115 are arranged at the four corners of the main tank 1. In terms of material selection, considering the cleanliness requirements of the drying process, its strength and rigidity can withstand reactive gases and do not affect the surface flatness of the air flow. Stainless steel 304 or aluminum alloy 8101, or other plastics such as PVDF, PVC, PTFE, etc. can be selected.

[0049] An injection water pipeline 120 is provided in the sunken channel. There is an injection pipe discharge hole on the injection water pipeline 120. The injection water pipeline 120 is connected to the external ultrapure water input pipeline through the internal tank liquid inlet 105 outside. The purpose is to release ultrapure water into the main tank 1 through the injection pipe discharge hole on the injection water pipeline 120 to achieve the infiltration and cleaning of the wafers. The injection water pipeline 120 is installed in the sunken channel at the bottom of the main tank 1. Outputting ultrapure water at this position plays a role of perfusion from the bottom up. Inputting from the bottom up can disturb the overall liquid refreshing ability during the perfusion process and disturb the liquid to continuously disturb the liquid, thereby maintaining the uniform distribution of the liquid.·

[0050] As Figure 6As shown in the figure, ultrapure water is injected into the ultrapure water tank 104 of the main tank 1 through the in-tank water inlet pipe as the injection water pipeline 120. The injection pipe discharge holes on the above injection water pipeline 120 are straight array holes that are upward and diffused to both sides. The straight array holes are a two-way array of holes, and each hole on the straight array holes corresponds to the central distance between wafers. With this design, the liquid can effectively correspond to the position of each wafer during injection, ensuring that each wafer can be evenly wetted while the ultrapure water is injected, and each position on the front and back of the batch of wafers can be wetted by the ultrapure water. In order to ensure that the flow field during the flow of ultrapure water does not affect the wafers, it is required that the distance between adjacent straight array holes below the wafer position is equal to the distance between adjacent wafers, and the distance between adjacent straight array holes at both sides below the wafer is greater than the distance between adjacent wafers, that is, the straight array holes are arranged at an enlarged distance at positions other than corresponding to the wafers. The purpose of this design is on the one hand to fully wet the wafers, and on the other hand to avoid the generation of turbulent flow due to the too-close distance of the ultrapure water ejected from both sides.

[0051] Overflow tanks are respectively arranged on both sides of the main tank 1 to discharge the overflowed ultrapure water and isopropyl alcohol residue liquid on the main tank 1. At the bottom of the overflow tank, there is an overflow waste liquid discharge port 114, and the overflow waste liquid discharge port 114 specifically leads out and discharges the overflowed ultrapure water and isopropyl alcohol residue liquid. The purpose of arranging the overflow tanks on both sides of the main tank 1 is to form a gradient effect of isopropyl alcohol concentration on the surface of the ultrapure water, so that the isopropyl alcohol concentration in the middle is greater than that at the edge, which is more conducive to the drying of the wafers. During the structural design, in order to realize the liquid overflow in the main tank 1, a plurality of V-shaped notches 107 for overflow are provided at the top of the main tank 1 near both sides of the overflow tanks. Among them, on one side of the main tank 1 with an overflow liquid inlet chamber 102, a plurality of the V-shaped notches 107 are arranged in rows, and a row of the overflow liquid inlet holes 108 is provided at the bottom of the V-shaped notches 107. The position of the overflow liquid inlet holes 108 corresponds to the V-shaped notches 107. The specific structure is as Figure 7 and Figure 8 shown. In addition, an overflow liquid inlet chamber 102 is provided in one of the overflow tanks. The overflow liquid inlet chamber 102 is connected to the external ultrapure water pipeline through an overflow liquid inlet pipe 109, and is connected to the main tank 1 through the overflow liquid inlet holes 108, and injects ultrapure water into the main tank 1 in a horizontal direction. Among them, the overflow liquid inlet chamber 102 plays a role of buffering and pressure accumulation, so that the ultrapure water injected from one side of the main tank 1 can be ejected with pressure and shoot horizontally to the other side. The normal ultrapure water is poured upward from the bottom of the main tank 1. Due to the large flow rate, it will cause upward scouring. By injecting ultrapure water horizontally, the scouring at the bottom can be alleviated, making the ultrapure water liquid level more stable, as can be clearly seen from the arrow direction in Figure 12 the figure.

[0052] The negative pressure chamber 103 is arranged on the outer sides of the overflow grooves on both sides of the main body tank 1 and is separated from the overflow grooves by a wall plate. The negative pressure chambers on both sides are connected to the exhaust air chamber on the back of the main body tank 1, and the gas can be discharged through the exhaust air ports 118 connected to the exhaust air chamber, forming a negative pressure exhaust air cavity. On the upper part of the overflow groove with an overflow liquid inlet chamber 102 on one side of the main body tank 1, a blind plate 112 is provided, and on the overflow groove 1 on the other side, a drainage channel formed by a guide plate 113 corresponding to the liquid overflow area is provided. As Figure 9 shown, the drainage channel is an inclined knife-shaped drainage ramp above the overflow groove, and the bottom of the inclined knife-shaped drainage ramp is aligned with the upper part of the negative pressure chamber 103. The negative pressure chamber 103 is communicated with the exhaust air chamber provided at the rear of the main body tank 1, and the exhaust air port 118 is provided at a position slightly above the bottom of the exhaust air chamber. Two exhaust waste liquid discharge ports 117 are provided at the bottom of the exhaust air chamber, and the two exhaust waste liquid discharge ports 117 are arranged on both sides of the air extraction port 118 respectively, aiming to collect and discharge part of the ultrapure water vapor and other waste liquids carried during negative pressure air extraction together. A good flow field design is to ensure that the isopropyl alcohol IPA mist is evenly distributed in the main body tank 1, and the air outside the tank body will not enter the tank body to contaminate the wafer. Therefore, the tank body is specially designed with a negative pressure exhaust air cavity, and a self-sealing flow field is formed through the special structure of the guide plate 113 to ensure the tightness of the tank body.

[0053] The above-mentioned negative pressure chamber 103 is separated from the overflow groove 101 by a wall plate. An exhaust hole is provided in the upper part of the wall plate, and the exhaust hole communicates the negative pressure chamber 103 and the overflow groove 101. The bottom of the guide plate 113 is opposite to the position of the exhaust hole. Specifically, two rows of the above-mentioned exhaust holes are provided, namely the upper exhaust holes 121 in the upper row and the lower exhaust holes 122 in the lower row, and the upper exhaust holes 121 and the lower exhaust holes 122 are arranged alternately. The guide plate 113 is inclined, and the bottom edge of the guide plate 113 is located between the upper exhaust holes 121 and the lower exhaust holes 122, as Figure 9 and Figure 10 shown.

[0054] A hole plate 110 is further provided in the main body tank 1. The hole plate 110 is installed at a height of 1 / 4 from the bottom of the main body tank 1 upward, above the injection pipe discharge hole of the injection water pipeline 120 and corresponding to the lower part of the wafer, as Figure 2 shown. The holes on the hole plate 110 are arranged in a uniform array, and the diameter of the holes is 10 mm - 15 mm. The position of the hole plate 110 is placed as Figure 2 shown. The main function of the hole plate 110 in the main body tank 1 is that when the liquid, that is, ultrapure water, is poured upward or discharged downward, the fluid can be guided into a downstream flow. That is, under the action of the numerous holes on the hole plate 110, the turbulent flow that may be generated by the rapidly ejected ultrapure water or the rapidly discharged ultrapure water is formed into a vertical downstream flow.

[0055] In the present invention, a dual-drainage design is adopted to achieve controllable liquid discharge and avoid droplet contamination of the wafer. In terms of structural design, the drain hole at the bottom of the sunken channel serves as the fast-drainage interface 106, and a fast-drainage valve is installed at the fast-drainage interface 106. A slow-drainage interface 119 is provided on the inner sidewall of the sunken channel, and the position of the slow-drainage interface 119 is also close to the bottom of the sunken channel. A slow-drainage valve is installed at the slow-drainage interface 119, as Figure 4 shown. Through the dual-drainage valve design of the slow-drainage valve and the fast-drainage valve, that is, a fast-drainage valve located at the bottom and a slow-drainage valve located on the sidewall are designed. When the liquid in the drying tank is at a high liquid level, the slow-drainage valve is activated to adopt a slow-drainage method, avoiding the phenomenon that the liquid level fluctuates violently due to too fast drainage speed when the wafer is close to the liquid surface, thus preventing droplet contamination of the bottom of the wafer. When the slow-drainage method causes the liquid level to drop to the middle liquid level, the liquid separates from the wafer, and then the fast-drainage valve can be opened to quickly drain the remaining liquid, improving the drying efficiency.

[0056] Through a new design, the present invention can optimize the drying tank structure of the swinging Marangoni drying flow field, making the wafer cleaning and drying processes more optimized through a new drying process. The implementation method is as Figure 11 shown. Now, the key links will be briefly described:

[0057] First step, perform operation preparation before drying. After the wafer is cleaned, the wafer is clamped by the wafer manipulator and horizontally transferred above the drying module. The drainage and exhaust pipelines and valves of the drying module are all in the closed state. Open the water inlet valve on the liquid inlet interface 105 in the tank, and inject ultrapure water through the injection water pipeline 120. When injecting ultrapure water, the liquid level can be observed through the liquid level detection interface 116 on the side of the main tank 1. After the main tank 1 is filled with water, close the water inlet valve. The drying chamber 3 of the drying module is horizontally moved away from the main tank 1 by the opening and closing mechanism 2, so that the upper part of the main tank 1 is opened, and the separation bracket 5 is moved to the uppermost position to facilitate the placement of the wafer 4;

[0058] Second step, perform the feeding (LOAD) operation. Place the wafer on the separation bracket inside the drying tank structure. The bottom of the separation bracket is the wafer support structure for carrying the wafer. After the wafer is placed, use the opening and closing mechanism 2 to horizontally move the drying chamber 3 so that the drying chamber 3 is closed with the main tank 1. At this time, the exhaust pipeline and valve of the drying module are all in the closed state;

[0059] In the third step, prepare for lift drying. Open the water inlet valve on the liquid inlet interface 105 in the tank and the overflow valve on the overflow liquid inlet pipe, and continuously perform large-flow overflow. Open the exhaust pipe to achieve exhaust operation. Continuously spray a mixture of isopropyl alcohol IPA and nitrogen N2. The lifting mechanism drives the separation bracket to move downward, so that the wafer support structure drives the wafer to move to the lowest position. Then, keep the water inlet valve and the overflow valve on the liquid inlet interface 105 in the tank open for small-flow overflow;

[0060] In the fourth step, perform lift drying. The lifting mechanism drives the separation bracket to move upward, and then the wafer is carried and lifted by the wafer support structure. During the upward movement, perform the elevation separation action;

[0061] In the fifth step, prepare for jet drying. Stop spraying the mixture of isopropyl alcohol IPA and nitrogen N2. The wafer 4 is lifted with the separation bracket 5, enters the drying chamber 3 from the main tank 1 along the lower guide plate 111, and is located between the two upper guide plates 32 in the drying chamber 3. Open the slow drainage, perform slow discharge of ultrapure water, so that the ultrapure water liquid level drops. The slow drainage interface 119 can be used to controllably adjust the discharge speed;

[0062] In the sixth step, perform jet drying. Start to spray heated nitrogen N2 alone. After the ultrapure water liquid level drops to the middle level through slow drainage, open the valve on the fast drainage interface 106 at the bottom of the main tank 1 to quickly drain the residual liquid in the tank;

[0063] In the seventh step, after the wafer 4 in the drying chamber 3 is dried, close the exhaust pipe to stop exhausting, stop spraying heated nitrogen N2, and the separation bracket 5 drives the wafer 4 to move downward, so that the wafer support structure returns to the initial position below the main tank body 1;

[0064] In the eighth step, after the wafer 4 is dried, the drying chamber 3 is horizontally translated away from the main tank 1 by the opening and closing mechanism 2. When the drying chamber 3 is horizontally moved by the opening and closing mechanism 2, it moves from the guide plate 113 at the top of the main tank 1 towards the blind plate 112. When moving, the special structural design of the guide plate 113 is combined with the negative pressure chamber 103. The negative pressure design can suck the air above the drying tank structure into the negative pressure chamber to prevent external air from entering the main tank 1 and contaminating the wafer 4. The separation bracket 5 drives the wafer to the uppermost position, and the wafer is taken away by the manipulator to complete the unloading operation;

[0065] In the ninth step, perform reset. After the wafer manipulator takes away the dried wafer 4, the lifting mechanism drives the separation bracket to move to the lowest position, and the opening and closing mechanism 2 drives the drying chamber 3 to horizontally translate and close with the main tank 1 to complete the overall drying operation.

[0066] The drying tank structure of the present invention can achieve uniform ultrapure water infiltration on both sides of a batch of wafers, and form a vertical downstream traction to avoid the generation of disordered turbulent flow. The negative pressure exhaust cavity is used to ensure uniform distribution of IPA mist in the cavity, and external air will not enter the cavity to contaminate the wafers.

[0067] Undoubtedly, the above are only limited implementation methods of the present invention. In addition, there can be other similar structural designs and operation processes. In short, the protection scope of the present invention also includes other transformations and substitutions that are obvious to those skilled in the art.

Claims

1. A drying tank structure for optimizing the Marangoni drying flow field of a swing type, characterized in that, The drying tank body structure includes: a main tank and an overflow tank, The main tank is a funnel-shaped main structure with a gentle slope for liquid discharge, including: A sunken channel, located at the bottom center of the main tank, having an inclined slope, and a discharge hole is provided at the lowest end of the slope; The discharge hole at the inner bottom of the sunken channel serves as a fast drainage interface, a fast drainage valve is installed at this fast drainage interface, a slow drainage interface is provided on the inner side wall of the sunken channel, and a slow drainage valve is installed at this slow drainage interface; An injection water pipeline, arranged in the sunken channel, and an injection pipe discharge hole is provided on the injection water pipeline; The injection pipe discharge holes on the injection water pipeline are straight array holes that diverge upward on both sides; At the position below the wafer, the spacing between adjacent straight array holes is equal to the spacing between adjacent wafers, and at the position outside the corresponding wafer, the spacing between adjacent straight array holes is greater than the spacing between adjacent wafers; The overflow tank is arranged on both sides of the main tank to discharge the overflowed ultrapure water and isopropyl alcohol residue liquid, including: An overflow liquid inlet chamber, arranged in the overflow tank on one side, is connected to the external ultrapure water pipeline through an overflow liquid inlet pipe, and is connected to the main tank through an overflow liquid inlet hole to inject ultrapure water into the main tank horizontally; A negative pressure chamber, arranged outside the overflow tanks on both sides, guides gas to be discharged through an exhaust port to form a negative pressure exhaust cavity; A blind plate is provided on the upper part of the overflow tank with an overflow liquid inlet chamber on one side of the main tank, and a drainage channel formed by a guide plate corresponding to the liquid overflow area is provided on the overflow tank on the other side; The drainage channel is an inclined knife-shaped drainage ramp above the overflow tank, and the bottom of the inclined knife-shaped drainage ramp is aligned with the upper part of the negative pressure chamber; The negative pressure chamber and the overflow tank are separated by a wall plate, an exhaust hole is provided in the upper part of the wall plate to connect the negative pressure chamber and the overflow tank, and the bottom of the guide plate is opposite to the position of the exhaust hole.

2. The drying tank structure for optimizing the Marangoni drying flow field of a swing type according to claim 1, characterized in that, A plurality of V-shaped notches for overflow are provided at the top of the main tank near the overflow tank.

3. The drying tank structure for optimizing the Marangoni drying flow field of a swing type according to claim 2, characterized in that, The V-shaped notches are arranged in rows, and a row of the overflow liquid inlet holes is provided at the bottom of the V-shaped grooves on the side with the overflow liquid inlet chamber.

4. The drying tank structure for optimizing the Marangoni drying flow field of a swing type according to claim 1, characterized in that, An overflow waste liquid discharge port is provided at the bottom of the overflow tank.

5. The drying tank structure for optimizing the Marangoni drying flow field of a swing type according to claim 1, characterized in that, The negative pressure chamber is connected to an exhaust chamber provided at the rear of the main tank, the exhaust port is provided at a position slightly above the bottom of the exhaust chamber, and an exhaust waste liquid discharge port is provided at the bottom of the exhaust chamber.

6. The drying tank structure for optimizing the Marangoni drying flow field of a swing type according to claim 1, characterized in that, A hole plate is further provided in the main tank, the hole plate is installed at a height position of 1 / 4 upward from the inner bottom of the main tank, and the hole plate is arranged above the injection pipe discharge hole and corresponding to the position below the wafer.

7. The drying tank structure for optimizing the Marangoni drying flow field of a swing type according to claim 6, characterized in that, The holes on the hole plate are arranged in an array evenly, and the diameter of the holes is 10 mm - 15 mm.

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