Chemical recoverable single wafer wafer cleaning apparatus

Abstract

This application relates to the field of semiconductor wafer processing and discloses a chemically recyclable monolithic wafer pickling device, including a housing and a drive mechanism. A wafer is placed on top of the drive mechanism. An exhaust vent is provided on the surface of the housing. A lead screw is mounted on the rear side of the inner wall of the housing. A recovery cylinder is slidably mounted on the outer side of the lead screw. A recovery chamber is provided inside the recovery cylinder. A balancing hole is provided at the top of the inner wall of the recovery chamber. A manifold is fixedly connected to the bottom of the recovery chamber. The device undergoes free fall in the vertical direction and eventually enters the recovery chamber at an angle equal to the height of the wafer. The liquid then flows along the manifold into a transfer tank for recycling. Three sets of recovery cylinders are connected by connecting blocks and can freely rise and fall under the action of the lead screw, allowing each set of recovery cylinders to be adapted to different cleaning media, thus making the recycling of the cleaning solution more efficient and environmentally friendly.

Description

Technical Field

[0001] This application relates to the field of semiconductor wafer processing technology, and in particular to a chemically recyclable monolithic wafer pickling apparatus. Background Technology

[0002] In the semiconductor wafer manufacturing process, after key processes such as wafer etching are completed, the wafers need to undergo chemical cleaning. Existing single-wafer cleaning processes typically involve a cleaning device driving the wafer to rotate at high speed, while a robotic arm positioned above the wafer sprays cleaning solutions or ultrapure water onto the wafer surface through pipes to perform acid washing. The centrifugal force generated by the wafer's rotation then ejects the surface cleaning waste liquid, which is then collected and recycled.

[0003] In existing single-wafer pickling operations, various acidic cleaning solutions, such as sulfuric acid, hydrochloric acid, and hydrofluoric acid, are often mixed and discharged together. This results in the acidic waste liquid mixing with heavy metal ions, significantly increasing the difficulty of subsequent separation, recovery, and reuse. Furthermore, the mixing of different types of pickling solutions can easily lead to chemical reactions, producing toxic and harmful gases, causing environmental pollution and safety hazards in the workshop. Therefore, there is an urgent need to improve the chemical solution recovery structure of wafer pickling equipment to achieve classified collection and recyclability of pickling solutions, solving the problems of mixed waste liquids, difficult recovery, and poor environmental performance in existing technologies. Summary of the Invention

[0004] This application proposes a chemically recyclable monolithic wafer pickling device, which has the advantages of easy classification and recycling and environmental protection, and is used to solve the problem caused by the mixing of cleaning waste liquid in the prior art.

[0005] To achieve the above objectives, this application adopts the following technical solution: a chemically recyclable monolithic wafer pickling device, which is used in conjunction with a robotic arm carrying a cleaning solution, including a housing and a drive mechanism. A wafer is placed on top of the drive mechanism, and an exhaust vent is provided on the surface of the housing. A lead screw is installed on the rear side of the inner wall of the housing. A recovery cylinder is slidably installed on the outer side of the lead screw. A recovery chamber is opened inside the recovery cylinder. A balance hole is opened at the top of the inner wall of the recovery chamber. A manifold is fixedly connected to the bottom of the recovery chamber. A transfer groove corresponding vertically to the manifold is installed at the bottom of the inner wall of the housing. An air supply mechanism is installed at the bottom of the inner wall of the outer shell. A connecting pipe protruding from the outer side of the outer shell is fixedly connected to the outer surface of the air supply mechanism. An annular cavity is opened inside the air supply mechanism. Multiple flow dividers are fixedly connected to the top of the inner wall of the annular cavity. The multiple flow dividers are distributed equidistantly along the inner wall of the annular cavity. Preferably, the driving mechanism includes a motor installed at the bottom of the housing, the output shaft of the motor is connected to a connecting shaft located in the inner cavity of the housing, a bearing plate is installed on the top of the connecting shaft, and a sealing sleeve is provided on the outer surface of the connecting shaft. The sealing sleeve is used to connect to an external negative pressure source so that the wafer can be firmly adsorbed and fixed on the upper surface of the bearing plate. The drive mechanism is used to provide support, rotational power and negative pressure fixation for the wafer. When the wafer is placed on the upper surface of the carrier plate, the negative pressure source connected to the sealing sleeve will directly transmit the negative pressure to the hole on the surface of the carrier plate. The wafer is fixed by the seal formed by the contact between the wafer and the carrier plate. Then, the motor drives the carrier plate and the wafer to rotate to complete the pickling preparation work.

[0006] Preferably, there are three sets of recycling cylinders, which are distributed longitudinally at equal intervals. The three sets of recycling cylinders are connected by connecting blocks, and the bottommost set of recycling cylinders is connected to a lead screw drive. Preferably, the three sets of recycling cylinders are staggered at 90° to each other, and the bottom of the outer shell has a number of drain ports equal to the number of recycling cylinders, which are connected to the transfer tank; The three sets of recovery cylinders are arranged in a staggered 90° pattern to ensure that their respective connecting manifolds do not interfere with each other. Each set of manifolds corresponds to a set of transfer tanks, so that the recovered cleaning fluid flows back to this tank and is discharged along the drain port to the next processing step.

[0007] Preferably, the inner wall of the outer shell is fixedly connected with four sets of sealing blocks that are circumferentially distributed. The surface of the sealing block is provided with a balance hole and a connecting port that connects to the exhaust port, and the recycling cylinder that connects to the connecting port is located on the uppermost side. The function of the sealing block is to ensure that it only coincides with one set of balance holes at a time. That is, when the recovery cylinder is at the same height as the wafer, the upward annular airflow from the air supply mechanism will partially enter the recovery chamber. At this time, the balance holes, connecting ports and exhaust ports can guide the airflow, thereby keeping the airflow direction between the inner cavity of the recovery chamber and the inner cavity of the outer shell from the outside (inner cavity of the outer shell) to the inside (inner cavity of the recovery chamber), thus preventing the cleaning fluid entering the inner cavity of the recovery chamber from being backflowed by the airflow.

[0008] Preferably, the wafer is at the same height as the middle of the uppermost set of recycling chambers, and the bottom of the recycling cylinder is provided with a horizontal ring, which is horizontal. A set of recovery cylinders at the same height as the wafer is used to receive cleaning fluid from the upper surface of the wafer in real time, while a horizontal ring is responsible for receiving cleaning fluid that is tilted too far downwards and cannot directly enter the recovery chamber.

[0009] Preferably, the bottom of the inner wall of the recovery chamber is provided with an inclined surface, and a bottom ring is fixedly installed at the bottom of the inner wall of the recovery chamber, the surface of the bottom ring being in communication with the manifold. The inclined bottom ring tends to guide the liquid entering the recovery chamber toward the side closer to the manifold, thereby avoiding liquid accumulation inside the recovery chamber.

[0010] Preferably, the bottom ring is composed of a first surface and a second surface, and the second surface is lower than the first surface; the recovery cylinder is generally inclined; and the manifold is connected to one side of the second surface. One side of the second surface is the lowest point of the entire recovery cylinder, which is connected to the manifold, so that the cleaning fluid entering the recovery chamber can quickly flow into the manifold.

[0011] The beneficial effects of this invention are as follows: 1. This device is equipped with three sets of synchronously lifting and lowering recovery cylinders. By using the centrifugal force of the rotating wafer in conjunction with the trajectory of the waste liquid ejection, different pickling solutions, ultrapure water and other cleaning media can be sorted and recovered separately, avoiding the mixing of multiple waste liquids, reducing the difficulty of subsequent separation and reuse, and eliminating the generation of toxic and harmful gases from mixing, thus significantly improving environmental protection.

[0012] 2. The system adopts a screw-driven multi-group lifting mechanism to lift multiple recycling cylinders as a whole, allowing for the switching of the corresponding recycling cylinder and wafer alignment to adapt to different cleaning processes. Combined with the air supply mechanism, it forms a stable annular airflow, which can limit the landing point of waste liquid and maintain the air pressure balance of the recycling chamber, preventing waste liquid backflow and leakage, resulting in higher recycling efficiency and operational stability.

[0013] 3. The bottom of the recovery chamber is equipped with a sloping bottom ring and staggered guide surfaces, which can quickly collect waste liquid and avoid liquid accumulation in the chamber; the sealing block and the balance hole are aligned and connected to achieve air and pressure stabilization of the recovery chamber that only works in alignment. The structure layout is reasonable and adaptable to the continuous operation requirements of single-wafer pickling of semiconductor wafers. Attached Figure Description

[0014] The accompanying drawings, which form part of this specification, illustrate embodiments disclosed in this application and, together with the specification, serve to explain the principles of this application in a clear and understandable manner.

[0015] This disclosure will become clearer with reference to the accompanying drawings and the following detailed description, wherein: Figure 1 This is a schematic diagram showing the overall structure of the present invention separated; Figure 2 This is a schematic diagram of the front view of the outer casing of the present invention; Figure 3 This is a top view of the outer casing of the present invention; Figure 4 This is a cross-sectional view of side a of the outer casing of the present invention; Figure 5 For the present invention Figure 4 Enlarged schematic diagram of the structure at point A; Figure 6This is a cross-sectional view of the shell of the present invention from side b. Figure 7 This is a cross-sectional view of the shell of the present invention from side c; Figure 8 For the present invention Figure 7 Enlarged schematic diagram of the structure at point B; Figure 9 This is a schematic diagram of the internal cross-section of the recycling cylinder of the present invention.

[0016] The components are as follows: 1. Outer shell; 2. Exhaust vent; 3. Drive mechanism; 31. Motor; 32. Connecting shaft; 33. Sealing sleeve; 34. Bearing plate; 4. Wafer; 5. Air supply mechanism; 51. Annular cavity; 52. Diverter plate; 53. Connecting pipe; 6. Drain port; 7. Lead screw; 8. Recovery cylinder; 81. Recovery chamber; 82. Transfer trough; 83. Manifold; 84. Bottom ring; 841. Surface No. 1; 842. Surface No. 2; 85. Horizontal ring; 86. Balance hole; 9. Connecting block; 10. Sealing block; 11. Connecting port. Detailed Implementation

[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0018] Please see Figures 1-9 This embodiment discloses a chemically recyclable monolithic wafer pickling device. This device works in conjunction with a robotic arm carrying a cleaning solution. It includes a housing 1 and a drive mechanism 3. A wafer 4 is placed on top of the drive mechanism 3. An exhaust vent 2 is provided on the surface of the housing 1. The lead screw 7 is installed on the rear side of the inner wall of the housing 1. A recovery cylinder 8 is slidably installed on the outer side of the lead screw 7. A recovery chamber 81 is opened inside the recovery cylinder 8. A balance hole 86 is opened at the top of the inner wall of the recovery chamber 81. A manifold 83 is fixedly connected to the bottom of the recovery chamber 81. A transfer groove 82 corresponding vertically to the manifold 83 is installed at the bottom of the inner wall of the housing 1. The air supply mechanism 5 is installed at the bottom of the inner wall of the outer shell 1. The outer surface of the air supply mechanism 5 is fixedly connected to a connecting pipe 53 protruding from the outer side of the outer shell 1. The air supply mechanism 5 has an annular cavity 51 inside. Multiple flow plates 52 are fixedly connected to the top of the inner wall of the annular cavity 51. The multiple flow plates 52 are distributed equidistantly along the inner wall of the annular cavity 51. This device has been redesigned with at least three sets of recovery cylinders 8 to receive different types of cleaning media that require separate recycling. It mainly utilizes the fact that when the cleaning fluid passes over the surface of the high-speed rotating wafer 4, it will detach from the wafer 4 under the action of centrifugal force. After detaching from the wafer 4, the cleaning fluid will move in a uniform linear motion in the horizontal direction and fall freely in the vertical direction, eventually entering the recovery chamber 81 at an angle equal to the height of the wafer 4. It will then converge into the transfer tank 82 along the manifold 83 to complete the recycling. The three sets of recovery cylinders 8 are connected by connecting blocks 9 and can be raised and lowered freely under the action of lead screws 7, so that each set of recovery cylinders 8 can be adapted to different cleaning media, thereby making the recycling of cleaning fluid more efficient and environmentally friendly.

[0019] In this embodiment, the drive mechanism 3 includes a motor 31 installed at the bottom of the housing 1. The output shaft of the motor 31 is equipped with a connecting shaft 32 located in the inner cavity of the housing 1. A bearing plate 34 is installed on the top of the connecting shaft 32. A sealing sleeve 33 is provided on the outer surface of the connecting shaft 32. The sealing sleeve 33 is used to connect to an external negative pressure source so that the wafer 4 can be firmly adsorbed and fixed on the upper surface of the bearing plate 34. like Figure 4 , Figure 6 As shown, the drive mechanism 3 is used to provide support, rotational power and negative pressure fixing function for the wafer 4. When the wafer 4 is placed on the upper surface of the carrier plate 34, the negative pressure source connected to the sealing sleeve 33 will directly transmit the negative pressure to the hole on the surface of the carrier plate 34. The sealing formed by the wafer 4 and the carrier plate 34 is used to fix the wafer 4. Then, the motor 31 drives the carrier plate 34 and the wafer 4 to rotate to complete the pickling preparation work.

[0020] In this embodiment, there are three sets of recycling cylinders 8, which are distributed longitudinally at equal intervals. The three sets of recycling cylinders 8 are connected by connecting blocks 9, and the bottommost set of recycling cylinders 8 is connected to the lead screw 7 for transmission. The three sets of recovery cylinders 8 in this device are connected to each other by connecting blocks 9, forming a complete unit. Driven by the lead screw 7, each set of recovery cylinders 8 moves up and down, allowing it to reach the same height as the wafer 4. At this point, the cleaning fluid ejected from the surface of the wafer 4 can enter the recovery chamber 81 for recovery. Different recovery cylinders 8 can accommodate different types of non-mixable cleaning media. A bottom ring 84 guides the cleaning fluid entering the recovery chamber 81, allowing it to quickly flow along the manifold 83 to the transfer tank. In section 82, the sealing block 10 abuts against the portion of the outer surface of the recovery cylinder 8 where the balance hole 86 is provided to form a seal. This ensures that only the balance hole 86 on the outer surface of the recovery cylinder 8, which moves to a height equal to that of the wafer 4, can coincide with the connecting port 11 and connect with the exhaust port 2. The purpose of this design is to guide the upward annular airflow from the air supply mechanism 5 into the inner cavity of the recovery chamber 81, and to help the cleaning fluid falling on the horizontal ring 85 and the inclined surface at the bottom of the inner wall of the recovery chamber 81 to fall into the manifold 83 more quickly and efficiently, thus improving the recovery efficiency.

[0021] In this embodiment, the three sets of recycling cylinders 8 are staggered at 90° to each other, and the bottom of the outer shell 1 has an equal number of drain ports 6 as the recycling cylinders 8. The drain ports 6 are connected to the transfer tank 82. like Figure 6 As shown, the three sets of recovery cylinders 8 are arranged in a staggered 90° pattern. Their function is to ensure that their respective connecting manifolds 83 do not interfere with each other. Each set of manifolds 83 corresponds to a set of transfer tanks 82, so that the recovered cleaning liquid is returned to this tank and discharged along the drain port 6 to the next processing step.

[0022] In this embodiment, four sets of sealing blocks 10 are fixedly connected to the inner wall of the outer shell 1 in a circumferentially equidistant arrangement. The surface of the sealing block 10 is provided with a balance hole 86 and a connecting port 11 that connects to the exhaust port 2. The recycling cylinder 8 that connects to the connecting port 11 is located at the top. like Figure 7 As shown, the function of the sealing block 10 is to ensure that it only coincides with one set of balance holes 86 at a time. That is, the annular airflow from the air supply mechanism 5 will partially enter the recovery chamber 81 when the recovery cylinder 8 is at the same height as the wafer 4. At this time, the balance hole 86, the connecting port 11 and the exhaust port 2 can guide the airflow, thereby keeping the airflow direction between the inner cavity of the recovery chamber 81 and the inner cavity of the outer shell 1 from the outside (inner cavity of the outer shell 1) to the inside (inner cavity of the recovery chamber 81), thereby preventing the cleaning fluid entering the inner cavity of the recovery chamber 81 from being backflowed by the airflow.

[0023] In this embodiment, the wafer 4 is at the same height as the middle of the set of recycling chambers 81 located on the uppermost side, and the bottom of the recycling cylinder 8 is provided with a horizontal ring 85, which is horizontal. like Figure 7As shown, a set of recycling cylinders 8 at the same height as wafer 4 are for immediate reception of cleaning fluid from the upper surface of wafer 4, and horizontal ring 85 is responsible for receiving cleaning fluid that is too tilted downwards to directly enter the inner cavity of recycling chamber 81.

[0024] In this embodiment, the bottom of the inner wall of the recovery chamber 81 is provided with an inclined surface, and a bottom ring 84 is fixedly installed at the bottom of the inner wall of the recovery chamber 81. The surface of the bottom ring 84 is in communication with the manifold 83. like Figure 1 , Figure 4 As shown, the bottom ring 84, which is set at an angle, tends to guide the liquid entering the inner cavity of the recovery chamber 81 toward the side closer to the manifold 83, thereby avoiding liquid accumulation inside the recovery chamber 81.

[0025] In this embodiment, the bottom ring 84 is composed of a first surface 841 and a second surface 842, and the second surface 842 is lower than the first surface 841. The recovery cylinder 8 is generally inclined, and the manifold 83 is connected to one side of the second surface 842. like Figure 1 As shown, one side of the second surface 842 is the lowest point of the entire recovery cylinder 8, which is connected to the manifold 83, so that the cleaning fluid entering the inner cavity of the recovery chamber 81 can quickly flow into the manifold 83.

[0026] Working principle: When this device is in operation: First, the robotic arm places the wafer 4 onto the carrier tray 34. A negative pressure source connected to the sealing sleeve 33 provides negative pressure to the carrier tray 34. Figure 6 As shown, the negative pressure hole on the top of the carrier disk 34 can apply negative pressure to the wafer 4, so that the wafer 4 is firmly fixed to the surface of the carrier disk 34. The motor 31 is started, and the connecting shaft 32, the carrier disk 34 and the wafer 4 are rotated. Then, the cleaning solution drips from the top of the device down to the middle of the upper surface of the wafer 4. As the wafer 4 continues to rotate, the cleaning solution continues to spread on the upper surface of the wafer 4. The centrifugal force generated pushes the solution and impurities to the periphery. The above mixed liquid will be directly thrown into the recovery chamber 81, which is at the same height as the wafer 4, and under the inclined guidance of the bottom ring 84, it flows back to the transfer tank 82 along the manifold 83. The cleaning solution can be adjusted to correspond to the height of the wafer 4 according to the different cleaning media such as pickling solution or ultrapure water. That is, a set of recovery cylinders 8 corresponds to a cleaning medium. The screw 7 can be activated to drive the recovery cylinders 8 to rise and fall as a whole, so that the corresponding recovery cylinders 8 can receive the cleaning medium continuously thrown out from the upper surface of the wafer 4. Finally, to prevent the cleaning fluid from continuously falling downwards due to gravity as it leaves the surface of wafer 4, a horizontally extending ring 85 is provided at the bottom of the recovery cylinder 8 to collect the cleaning fluid. Furthermore, a positive pressure air source is connected to the connecting pipe 53. The positive pressure airflow enters the diverter plate 52 through the connecting pipe 53 and is diverted by the diverter plate 52 as it moves upwards, forming a uniform, vertically upward-flowing annular airflow. This annular airflow passes upwards through the annular area between the inner side of the horizontal ring 85 and the outer side of wafer 4, counteracting the downward fall of the cleaning fluid that detaches from the surface of wafer 4 due to gravity, ensuring that the cleaning fluid ejected along the upper surface of wafer 4 can enter the corresponding recovery chamber 81. Figure 7 As shown, the upward-moving annular airflow enters a set of recovery chambers 81 with the same height as the wafer 4, and then exits through the balance hole 86 and the connecting port 11 to form a pressure balance. At the same time, an inward wind pressure is formed in the inner cavity of the recovery chamber 81, so that the cleaning fluid entering the recovery chamber 81 can enter the manifold 83 more quickly.

[0027] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A chemically recyclable monolithic wafer pickling device, which is used in conjunction with a robotic arm carrying a cleaning solution, includes a housing (1) and a drive mechanism (3), wherein a wafer (4) is placed on top of the drive mechanism (3), and an exhaust vent (2) is provided on the surface of the housing (1), characterized in that, include: A lead screw (7) is installed on the rear side of the inner wall of the outer casing (1). A recycling cylinder (8) is slidably installed on the outer side of the lead screw (7). A recycling chamber (81) is opened inside the recycling cylinder (8). A balance hole (86) is opened on the top of the inner wall of the recycling chamber (81). A manifold (83) is fixedly connected to the bottom of the recycling chamber (81). A transfer groove (82) corresponding vertically to the manifold (83) is installed on the bottom of the inner wall of the outer casing (1). An air supply mechanism (5) is installed at the bottom of the inner wall of the outer shell (1). A connecting pipe (53) protruding from the outer side of the outer shell (1) is fixedly connected to the outer surface of the air supply mechanism (5). An annular cavity (51) is opened inside the air supply mechanism (5). Multiple diverter plates (52) are fixedly connected to the top of the inner wall of the annular cavity (51). The multiple diverter plates (52) are distributed equidistantly along the inner wall of the annular cavity (51).

2. The chemical recyclable monolithic wafer pickling device according to claim 1, characterized in that, The drive mechanism (3) includes a motor (31) installed at the bottom of the housing (1). The output shaft of the motor (31) is equipped with a connecting shaft (32) located in the inner cavity of the housing (1). A bearing plate (34) is installed on the top of the connecting shaft (32). A sealing sleeve (33) is provided on the outer surface of the connecting shaft (32). The sealing sleeve (33) is used to connect to an external negative pressure source so that the wafer (4) can be firmly adsorbed and fixed on the upper surface of the bearing plate (34).

3. The chemically recyclable monolithic wafer pickling device according to claim 2, characterized in that, The number of the recycling cylinders (8) is three sets, which are distributed longitudinally at equal intervals. The three sets of recycling cylinders (8) are connected by connecting blocks (9). The recycling cylinder (8) located at the bottom is connected to the lead screw (7) for transmission.

4. The chemically recyclable monolithic wafer pickling device according to claim 3, characterized in that, The three sets of recycling cylinders (8) are staggered at 90° to each other. The bottom of the outer shell (1) has an equal number of drain ports (6) as the recycling cylinders (8). The drain ports (6) are connected to the transfer tank (82).

5. A chemically recyclable monolithic wafer pickling device according to claim 4, characterized in that, The inner wall of the outer shell (1) is fixedly connected with four sets of sealing blocks (10) distributed equidistantly in a circle. The surface of the sealing block (10) is provided with a balance hole (86) and a connecting port (11) that connects to the exhaust port (2). The recycling cylinder (8) connected to the connecting port (11) is located on the uppermost side.

6. The chemically recyclable monolithic wafer pickling device according to claim 5, characterized in that, The wafer (4) is at the same height as the middle of a set of recycling chambers (81) located on the uppermost side, and a horizontal ring (85) is provided at the bottom of the recycling cylinder (8), and the horizontal ring (85) is horizontal.

7. A single-wafer pickling device for chemical recyclability according to claim 6, characterized in that, The bottom of the inner wall of the recovery chamber (81) is provided with an inclined surface, and a bottom ring (84) is fixedly installed at the bottom of the inner wall of the recovery chamber (81). The surface of the bottom ring (84) is in communication with the manifold (83).

8. A chemically recyclable monolithic wafer pickling device according to claim 7, characterized in that, The bottom ring (84) is composed of a first surface (841) and a second surface (842), and the second surface (842) is lower than the first surface (841). The recycling cylinder (8) is generally inclined, and the manifold (83) is connected to one side of the second surface (842).

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