A developing device with stable backflow prevention

Abstract

The application discloses a stable backflow-preventing developing device, which comprises a wafer adsorption structure, a baffle, an air duct structure, a gas supply channel, a retainer rail, a retainer and a distance sensor; the wafer adsorption structure is installed on a motor shaft; the baffle is fixed above a base; the air duct structure is installed in a negative pressure cavity, and the bottom of the air duct structure is provided with the gas supply channel; the retainer rail is installed in a top-end groove of the baffle; the retainer is connected with the upper surface of the retainer rail; and the distance sensor is located above the wafer. The application has the following beneficial effects: the roller is used to position the vacuum suction head, and the annular flat air port is used to blow out the developing liquid, so that the stability and safety of the process are ensured; the horizontal compensation mechanism can ensure that the wafer horizontal state is stable while the developing liquid is blown out, and the process quality is improved; the blowing-out process of the backflow developing liquid can be automatically and real-timely adjusted, so that the adjustment is more accurate and reliable; the double-layer protection of the air duct and the retainer with the slope is adopted, so that the removal effect of the backflow developing liquid is enhanced.

Description

Technical Field

[0001] This invention relates to the field of wafer manufacturing, and more particularly to a stable anti-backflow developing apparatus. Background Technology

[0002] Wafers are one of the essential raw materials used in chip manufacturing, and wafer production is a key component of the semiconductor industry. Wafer fabrication typically employs a single-crystal vertical method, where high-purity polycrystalline silicon is grown on a daughter crystal to form a cylindrical silicon rod. This rod is then polished and sliced ​​to form a preliminary wafer. Before the wafer dicing process, coating, exposure, and development processes are required on the wafer surface. The development process, in particular, uses a developing solution to develop the pattern transferred onto the photosensitive material; the quality of this developed pattern significantly impacts subsequent processes and the final product.

[0003] During wafer development, developer often accidentally flows onto the back of the wafer due to factors such as vacuum suction head misalignment, uneven developer distribution, and unstable wafer rotation, affecting wafer quality. If not addressed promptly, this developer can continue to flow into the motor housing, suction head, and even the motor itself, leading to more serious consequences.

[0004] To address these issues, most coating machines on the market currently use baffles or retaining rings to prevent developer from flowing in. However, some existing improved designs can better meet these requirements. For example, a developing apparatus for preventing backside contamination of wafers, disclosed in Chinese patent literature (CN204903943U), includes a rotating baffle that can move up, down, left, and right, and a retaining ring that moves with the rotating baffle. By changing the installation method of the internal rotating baffle, and using the telescopic movement of the vertical and horizontal plates to move the internal rotating baffle, the gap between the retaining ring and the wafer is eliminated. This prevents contamination of the wafer, internal rotating baffle, and vacuum column caused by developer flowing in from the wafer surface, thus improving product yield.

[0005] This design uses a movable rotating baffle to adjust the gap between the retainer ring and the wafer, which can block some of the developer. However, if the developer flows in from multiple directions, or if the retainer ring deforms due to vibration or other reasons, the retainer ring's function will be partially ineffective, failing to achieve the intended protective effect. Contact will occur between the retainer ring and the wafer; as the wafer rotates around its axis while the retainer ring remains fixed with the rotating baffle, friction will inevitably occur, causing damage to the wafer. Furthermore, the baffle adjustment is manual and requires real-time adjustment, making it extremely difficult to maintain precise manual adjustment during wafer rotation. Summary of the Invention

[0006] This invention aims to overcome safety and device reliability issues in existing technologies by providing a developing apparatus that can stabilize the position of the vacuum suction head and prevent developer backflow. An automatic air supply device is used to promptly blow out excess developer flowing into the back of the wafer, preventing contamination of the equipment and the back of the wafer.

[0007] To solve the above problems, the present invention adopts the following technical solution.

[0008] A stable anti-backflow developing device includes a wafer adsorption structure, a baffle, an air duct structure, an air supply channel, a protective ring guide rail, a protective ring, a distance sensor, and a wafer. The wafer adsorption structure is mounted on a motor shaft, and the motor shaft and a corresponding motor are fixed above a base. The bottom of the wafer adsorption structure is connected to the bottom of a negative pressure chamber. The baffle is fixed above the base. The air duct structure is installed inside the negative pressure chamber, and an air supply channel is provided at the bottom of the air duct structure. The protective ring guide rail is installed in a groove at the top of the baffle. The protective ring is connected to the upper surface of the protective ring guide rail, and its lower end lightly touches the outer side of the top of the baffle. The distance sensor is located above the wafer and is fixed on a top cover.

[0009] Preferably, the wafer adsorption structure includes a vacuum suction head, a guide sleeve, a suction head support, and rollers. The vacuum suction head and suction head support can be an integral or detachable structure, and the guide sleeve is fixed to the bottom of the negative pressure chamber.

[0010] Preferably, there are at least three rollers, which are evenly distributed at the same height on the outside of the suction head support, contact the guide sleeve and roll on the inner side of the sleeve; since the vacuum suction head and suction head support rotate with the motor shaft, the rollers can be used for rolling friction to ensure that the structural wear is reduced while the suction head is limited.

[0011] Preferably, the air duct structure mainly consists of two flared structures, including an inner air duct layer, an outer air duct layer, and connecting parts. The inner air duct layer is fixed to the outer side of the guide sleeve and connected to the outer air duct layer through several connecting parts. The flat annular air outlet can better match the shape of the gap where the developer penetrates, and can avoid the problem of poor blowing effect caused by the dispersion of air force in a typical circular air outlet.

[0012] Preferably, the number of the connecting parts is not less than 4 and is even, and they are evenly distributed along the circumference. The area between two connecting parts is an independent air vent. When the liquid is blown out, the wafer will be pushed upward a short distance at the same time, causing the wafer to deviate from the horizontal plane. The even number ensures that there are air vents on opposite sides that can blow out air at the same time to compensate.

[0013] Preferably, the number of air supply channels is equal to the number of connecting parts, including air valves and air supply pipes. The air valves have three states: open, half-open, and closed. The air supply pipes are connected to the air supply device. The half-open state of the valves is used to achieve horizontal position compensation of the wafers.

[0014] Preferably, the retaining ring guide rail consists of a retaining ring cover, a ball bearing disk, and a retaining ring base; the retaining ring cover and the retaining ring base have the same structure, and their internal concave arc surfaces are in close contact with the ball bearing disk; when the wafer touches and rotates with the retaining ring, the retaining ring and the retaining ring guide rail rotate with the wafer, avoiding damage to the back of the wafer caused by sliding friction.

[0015] Preferably, the retaining ring is made of a material with high plasticity, with a sloping top that is higher on the inside and lower on the outside, and the sloping angle is between 30 and 60 degrees. For developer that has not been completely drained by the drainage structure, the retaining ring is needed as an auxiliary drainage structure. The sloping design of the retaining ring helps the developer to flow down the slope according to its own tension and gravity, which is better than the usual flat design.

[0016] Preferably, the number of distance sensors is the same as the number of connecting parts, and their arrangement is adapted to the location of the air vent; the air valve, distance sensors and controller are connected; since the push rod and air supply channel are arranged in the housing or near the base, the controller connection method can be wired connection or wireless signal connection.

[0017] Therefore, the present invention has the following beneficial effects: (1) Rollers are used to position the vacuum suction head to prevent displacement, and a ring-shaped flat air outlet is used to blow out the developer on the back of the wafer, ensuring the stability and safety of the process. (2) The horizontal compensation mechanism can ensure the stable level of the wafer while blowing out the developer, improving the process quality. (3) The blowing process of the backflow developer can be automatically adjusted in real time throughout the entire process, making the adjustment more precise and reliable. (4) The use of air ducts and double-layer protection with inclined protective rings enhances the removal effect of the backflow developer. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0019] Figure 2 This is a schematic diagram of the air duct structure and air supply channel of the present invention.

[0020] Figure 3 This is a structural schematic diagram of the protective ring and the protective ring guide rail of the present invention.

[0021] In the diagram: 1-Wafer adsorption structure, 11-Vacuum nozzle, 12-Guide sleeve, 13-Nozzle support, 14-Roller, 2-Baffle, 3-Air duct structure, 31-Inner layer of air duct, 32-Outer layer of air duct, 33-Connecting part, 4-Air supply channel, 41-Air valve, 42-Air supply pipe, 5-Guard ring guide rail, 51-Guard ring cover, 52-Ball bearing disc, 53-Guard ring base, 6-Guard ring, 7-Distance sensor, 8-Wafer. Detailed Implementation

[0022] The embodiments of the present invention will be further described below through specific examples and in conjunction with the accompanying drawings.

[0023] like Figures 1-3 As shown, the present invention relates to a stable anti-backflow developing device, comprising a wafer adsorption structure 1, a baffle 2, an air duct structure 3, an air supply channel 4, a protective ring guide rail 5, a protective ring 6, a distance sensor 7, and a wafer 8; the wafer adsorption structure 1 is mounted on a motor shaft, the motor shaft and a corresponding motor are fixed above the base, and the bottom of the wafer adsorption structure 1 is connected to the bottom of the negative pressure chamber; the baffle 2 is fixed above the base; the air duct structure 3 is installed inside the negative pressure chamber, and the bottom of the air duct structure 3 is provided with an air supply channel 4; the protective ring guide rail 5 is installed in the groove at the top of the baffle 2; the protective ring 6 is connected to the upper surface of the protective ring guide rail 5, and its lower end lightly touches the outer side of the top of the baffle 2; the distance sensor 7 is located above the wafer 8 and is fixed on the top cover.

[0024] Specifically, the wafer adsorption structure 1 includes a vacuum suction head 11, a guide sleeve 12, a suction head support 13, and a roller 14. The vacuum suction head 11 and the suction head support 13 can be an integral or detachable structure, and the guide sleeve 12 is fixed to the bottom of the negative pressure chamber.

[0025] Specifically, there are at least three rollers 14, which are evenly distributed at the same height on the outside of the suction head support 13, contact the guide sleeve 12 and roll on the inner side of the sleeve.

[0026] Specifically, the air duct structure 3 is mainly composed of two flared structures, including an inner air duct layer 31, an outer air duct layer 32, and a connecting part 33. The inner air duct layer 31 is fixed to the outer side of the guide sleeve 12 and is connected to the outer air duct layer 32 through several connecting parts 33.

[0027] Specifically, the number of connecting parts 33 is not less than 4 and is an even number, and they are evenly distributed along the circumference. The area between two connecting parts 33 is their own independent air vent.

[0028] Specifically, the number of air supply channels is equal to the number of connecting parts 33, including air valves 41 and air supply pipes 42. The air valves 41 have three states: open, half-open, and closed. The air supply pipes 42 are connected to the air supply device.

[0029] Specifically, the guard ring guide rail 5 is composed of a guard ring cover 51, a ball bearing disc 52 and a guard ring base 53; the guard ring cover 51 and the guard ring base 53 have the same structure, and their internal concave arc surfaces are tightly fitted with the ball bearing disc 52.

[0030] Specifically, the protective ring 6 is made of a material with high plasticity, with a sloping top that is higher on the inside and lower on the outside, and the sloping angle is between 30 and 60 degrees.

[0031] Specifically, the number of distance sensors 7 is the same as the number of connecting parts 33, and their arrangement is adapted to the position of the air vent; the air valve 41, the distance sensors 7 and the controller are connected.

[0032] The working process of this invention is as follows.

[0033] like Figures 1-3 As shown, during operation, the vacuum head and motor start; the motor drives the vacuum head to rotate, and the vacuum head picks up the wafer, forming a negative pressure air layer between them; the retainer ring, retainer ring guide rail, and wafer rotate with the vacuum head, while developer is injected from above towards the center of the wafer for development. When the developer increases on one side, causing the wafer to tilt, a gap will appear at the contact point between the wafer and the retainer ring on the other side. At this time, the distance sensor detects the tilt signal, and the controller opens one or more corresponding air valves to blow out the developer; at the same time, the opposite air valve is partially opened for horizontal position compensation, closing the gap and restoring the retainer ring's blocking effect. After the wafer position returns to horizontal, the distance sensor detects the signal, and the controller drives the air valve to close, ending the blowing action. During wafer development, the above process can be automatically repeated multiple times until the development process is complete.

[0034] The above embodiments are only used to further illustrate the present invention of a stable anti-backflow developing device, but the present invention is not limited to the embodiments. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A stable anti-backflow developing apparatus, characterized in that: The device includes a wafer adsorption structure (1), a baffle (2), an air duct structure (3), an air supply channel (4), a protective ring guide rail (5), a protective ring (6), and a distance sensor (7). The wafer adsorption structure (1) is mounted on a motor shaft, and the motor shaft and the corresponding motor are fixed above the base. The bottom of the wafer adsorption structure (1) is connected to the bottom of the negative pressure chamber. The baffle (2) is fixed above the base. The air duct structure (3) is installed inside the negative pressure chamber, and the bottom of the air duct structure (3) is provided with an air supply channel (4). The protective ring guide rail (5) is installed in the groove at the top of the baffle (2). The protective ring (6) is connected to the upper surface of the protective ring guide rail (5), and its lower end lightly touches the outer side of the top of the baffle (2). The distance sensor (7) is located above the wafer (8) and is fixed on the top cover. The wafer adsorption structure includes a vacuum nozzle, a guide sleeve, a nozzle support, and rollers; The air duct structure includes an inner air duct layer, an outer air duct layer, and connecting parts. The inner air duct layer is connected to the outer air duct layer through several connecting parts. The retaining ring guide rail consists of a retaining ring cover, a ball bearing disc, and a retaining ring base; the inner structure of the retaining ring cover and the retaining ring base is the same, and the inner concave arc surface fits into the ball bearing disc.

2. The developing apparatus for stable anti-backflow according to claim 1, characterized in that: The vacuum suction head (11) and suction head support (13) adopt an integrated or detachable structure, and the guide sleeve (12) is fixed to the bottom of the negative pressure chamber.

3. The developing apparatus for stable anti-backflow according to claim 2, characterized in that: The number of rollers (14) is at least 3, which are evenly distributed at the same height on the outside of the suction head support (13), and contact the guide sleeve (12) and roll on the inner side of the sleeve.

4. The developing apparatus for stable anti-backflow according to claim 1, characterized in that: The air duct structure (3) is mainly composed of two layers of horn-shaped structures, with the inner layer (31) of the air duct fixed to the outer side of the guide sleeve (12).

5. A developing apparatus for stable anti-backflow according to claim 3, characterized in that: The number of the connecting parts (33) is not less than 4 and is an even number, and they are evenly distributed along the circumference. The area between two adjacent connecting parts (33) is their own independent air vent.

6. The developing apparatus for stable anti-backflow according to claim 1, characterized in that: The number of gas supply channels (4) is equal to the number of connecting parts (33). Each gas supply channel (4) includes a gas valve (41) and a gas supply pipe (42). The gas valve (41) has three states: open, half-open, and closed. The gas supply pipe (42) is connected to the gas supply device.

7. The developing apparatus for stable anti-backflow according to claim 1, characterized in that: The protective ring (6) is made of plastic material, with a sloping top that is higher on the inside and lower on the outside, and the sloping angle is between 30 and 60 degrees.

8. A developing apparatus for stable anti-backflow according to claim 6, characterized in that: The number of distance sensors (7) is the same as the number of connecting parts (33), and their arrangement is adapted to the position of the air vent; the air valve (41), distance sensors (7) are connected to the controller.

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