Wafer wiping device

Abstract

The invention relates to the technical field of silicon wafer processing, in particular to a wafer wiping device which comprises a base, a jig table is installed on the base, and a containing groove is formed in the top of the jig table and used for bearing a wafer. An air cavity is formed in the jig table, and a plurality of air ports communicating with the air cavity are formed in the bottom face of the containing groove. An air injection pipe and an air exhaust pipe which are communicated with the interior of the air cavity are mounted on the side edge of the jig table; two positioning plates are mounted on the base in a sliding manner; through the arrangement of the air port, air flow can be continuously blown to the bottom end face of the wafer when the air port blows air according to the change of the air flow in the air cavity, and continuous impurity removal of the bottom end face of the wafer is formed in the whole process; when the air inlet is changed into air inlet from air blowing, negative pressure can be formed at the air inlet, and adsorption is formed between the air inlet and the bottom end face of the cleaned wafer, so that the wafer is fixed in the placement groove, damage caused when the wafer is clamped and fixed by an existing clamp is avoided, and a worker can conveniently wipe dirt at the mark point of the wafer adsorbed and fixed in the placement groove.

Description

Technical Field

[0001] The invention relates to the technical field of silicon wafer processing, and in particular to a wafer wiping device. Background Art

[0002] In the semiconductor manufacturing process, wafer MARK marking is a reliable marking technology performed on wafer chips, which is used to identify and track wafers during the production process. However, during the subsequent manufacturing process, the marking points may be blocked by dirt, causing the marks to become unclear, affecting the identification and tracking accuracy of the wafer. Usually, the wafer is positioned and the dirt at the marking points is wiped clean.

[0003] Existing wafer positioning devices mostly use a pressing block combined with a rubber pad to fix the wafer on the base; although this method avoids the pressing block from directly contacting the wafer surface to a certain extent, thereby protecting the surface quality of the wafer, it still has the following shortcomings in actual use: First, the rubber pad is in direct contact with the upper surface of the wafer. During batch processing, the rubber pad frequently contacts different wafers, which can easily accumulate impurities and even form agglomerates. These impurities may directly damage the wafer surface during the subsequent clamping process. Secondly, if there is dust or hard impurities on the bottom surface of the wafer, the wafer may be damaged during the pressing process, thereby affecting its subsequent manufacturing process. Summary of the invention

[0004] The present invention provides a wafer wiping device, which can clean the bottom surface of the wafer before the wafer is positioned and clamped, and form an adsorption clamping for the wafer after cleaning. The specific scheme is as follows: A wafer wiping device comprises a base, a jig table is mounted on the base, a placement groove is provided on the top of the jig table for carrying wafers; an air cavity is formed in the jig table, and a plurality of air ports connected to the air cavity are provided on the bottom surface of the placement groove; an air injection pipe and an air extraction pipe connected to the inside of the air cavity are mounted on the side of the jig table for selectively controlling the change of airflow in the air cavity; two positioning plates are slidably mounted on the base, both of which are located above the jig table and are used to limit the wafer from leaving the placement groove.

[0005] Furthermore, a cleaning window is passed through the positioning plate to expose the wafer area to be cleaned; a cleaning liquid nozzle is installed on the top of each of the two positioning plates, and the cleaning liquid nozzle is located at the adjacent ends of the two positioning plates to spray cleaning liquid onto the surface of the wafer area to be cleaned.

[0006] Furthermore, a bracket that can be raised and lowered is provided at the top of the positioning plate; rotating columns are installed at the four corners of the bracket, and any rotating column can form a continuous rotation motion; and a wiping belt is tightly sleeved between the four rotating columns.

[0007] Further, the wiping belt is made of rubber, and its head and tail are closed and tightly sleeved between the four rotating columns.

[0008] Further, a cleaning tank is also installed on the bracket; a positioning column is rotatably installed in the cleaning tank; wherein, the positioning column is used to limit the wiping belt between the two rotating columns above to sink into the cleaning liquid in the cleaning tank.

[0009] Further, a drying strip that fits the surface of the wiping belt is also installed in the cleaning tank, which is used to remove the residual liquid on the surface of the wiping belt.

[0010] Further, the bottom of the cleaning tank is connected with a water inlet pipe and a water outlet pipe, and the water inlet pipe and the water outlet pipe are connected to an external water pump through a hose to realize the liquid circulation and replacement in the cleaning tank.

[0011] Further, mounting grooves are opened at the bottoms of the adjacent ends of the two positioning plates, and cylindrical water-absorbing sponges are embedded in the mounting grooves for adsorbing the residual liquid drops on the surface of the wafer.

[0012] Further, a flat cut is provided on the surface of the water-absorbing sponge, and a shaft rod rotatably connected to the positioning plate is coaxially installed inside the water-absorbing sponge; a servo motor is also installed on the side of the positioning plate; either end of the shaft rod extends out of the side of the positioning plate and is connected to the output shaft of the servo motor.

[0013] Further, a plurality of air ducts are also installed on the top of the positioning plate, and the air outlets of the air ducts are located in the mounting grooves.

[0014] Compared with the prior art, the present invention can at least achieve the following beneficial effects: Through the setting of the air port, the device can, according to the change of the air flow in the air cavity, when blowing air at the air port, the air flow will continuously blow towards the bottom end surface of the wafer and be discharged from the gap between the wafer and the placement groove, and continuous impurity removal of the bottom end surface of the wafer is formed during the whole process; And when the air port changes from blowing air to taking in air, a negative pressure will be formed at the air port and adsorb with the bottom end surface of the wafer after cleaning, so that the wafer is fixed in the placement groove, avoiding the damage formed when the existing fixture clamps and fixes the wafer, and facilitating the wiping work of the dirt at the marking point of the wafer adsorbed and fixed in the placement groove by the staff. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts. Among them: Figure 1 It is the overall structural schematic diagram of the present invention.

[0016] Figure 2 This is a schematic structural view of the wafer of the present invention located in the placement groove.

[0017] Figure 3 This is a schematic structural view of the air cavity of the present invention.

[0018] Figure 4 For the present invention Figure 2 a partial structural schematic view.

[0019] Figure 5 This is a schematic internal structure view of the cleaning box of the present invention.

[0020] Figure 6 This is a schematic bottom view structure of the positioning plate of the present invention.

[0021] Figure 7 This is a schematic top view structure of the positioning plate of the present invention.

[0022] Figure 8 This is a schematic sectional view structure of the positioning plate of the present invention.

[0023] Figure 9 This is another state schematic view of the water - blowing sponge of the present invention.

[0024] Among them, the reference numerals are as follows: 1. Base; 11. Fixture table; 111. Placement groove; 112. Air cavity; 113. Air port; 12. Injection pipe; 13. Extraction pipe; 14. Positioning plate; 2. Bracket; 21. Rotating column; 22. Wiping belt; 23. Cleaning liquid spray head; 24. Cleaning box; 241. Positioning column; 242. Drying strip; 3. Installation groove; 31. Water - removing sponge; 311. Flat cut; 32. Servo motor; 33. Air duct. Detailed implementation manners

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0026] Please first refer to Figure 1 and Figure 2As shown, the present invention provides a wafer wiping device, including a base 1, on which a jig table 11 is installed, and a circular placement groove 111 is provided on the top of the jig table 11 for carrying the wafer to be wiped and cleaned; an air cavity 112 is formed in the jig table 11, and a plurality of air ports 113 connected to the air cavity 112 are provided on the bottom surface of the placement groove 111; an air injection pipe 12 and an air extraction pipe 13 connected to the air cavity 112 are installed on the side of the jig table 11, and the air injection pipe 12 and the air extraction pipe 13 are respectively connected to an external air pump through a one-way valve hose, which are used to selectively control the change of air flow in the air cavity 112, and to form a continuous injection of gas into the air cavity 112 or a negative pressure extraction of gas; two positioning plates 14 are slidably installed on the base 1 through a slide rail, and are both located above the jig table 11. The two positioning plates 14 can be controlled by an external bidirectional screw rod and a slider structure to realize synchronous movement toward / away from each other. When the two positioning plates 14 move relative to each other and reach the top of the jig table 11, they are used to limit the wafer from leaving the placement groove 111; It is worth noting that the overall thickness of the wafer to be cleaned is greater than the depth of the placement groove 111. After the wafer is located in the placement groove 111, there is a gap between the wafer and the positioning plate 14. The top surface of the wafer protrudes above the placement groove 111 but does not contact the bottom surface of the positioning plate 14, so as to avoid the positioning plate 14 from scratching the top surface of the wafer in the placement groove 111 during the lateral movement. When in use: after the wafer is placed in the placement groove 111 manually or by equipment, the external air pump can be operated first to make the air injection pipe 12 introduce the airflow that is continuously injected into the air cavity 112, and the airflow in the air cavity 112 is continuously blown from the air port 113 to the bottom end surface of the wafer. Due to the restriction of the positioning plate 14 on the wafer, the wafer can be lifted up and fit the bottom end surface of the positioning plate 14, and the airflow is continuously blown to the bottom end surface of the wafer and discharged from the gap between the wafer and the placement groove 111. The whole process forms a continuous removal of impurities on the bottom end surface of the wafer; Subsequently, the external air pump is used to stop the air injection pipe 12 from injecting air into the air cavity 112, and the wafer falls on the bottom surface of the placement groove 111 by gravity. At this time, the external air pump is used to make the exhaust pipe 13 suck the gas in the air cavity 112, so that negative pressure is formed at the air port 113 and adsorbed with the bottom end surface of the cleaned wafer, so that the wafer is fixed in the placement groove 111, avoiding damage to the wafer when the existing clamp is clamped and fixed, and facilitating the staff to wipe the dirt at the marking point of the wafer adsorbed and fixed in the placement groove 111, and the fixed wafer (wafer positioning point) will not deflect and move during the wiping process.

[0027] Reference Figure 2 , Figure 4 and Figure 7As shown, a cleaning window penetrates through the positioning plate 14. After the positioning plate 14 is located above the wafer, this cleaning window is used to expose the area of the wafer to be cleaned, and this cleaning area is at the marking point of the wafer; A cleaning liquid spray head 23 is installed on the top of each of the two positioning plates 14. The cleaning liquid spray head 23 is located at the adjacent end of the two positioning plates 14. The cleaning liquid spray head 23 is externally connected to a pump body, and is used to spray cleaning liquid from the cleaning liquid spray head 23 onto the surface of the area of the wafer to be cleaned. The cleaning liquid can be SC1 solution, hydrofluoric acid, deionized water, etc.; During use: After the wafer is adsorbed and fixed and the positioning plate 14 is located above the wafer, cleaning liquid can be sprayed through the cleaning liquid spray head 23 onto the cleaning area circled by the cleaning window, and then it is convenient for manual or equipment to intervene to clean the dirt at the marking point, improving the wiping quality; The setting of the cleaning window on the positioning plate 14 only exposes the marking points of the wafer that need to be cleaned, and the rest of the positions are relatively covered by the positioning plate 14. When the cleaning liquid is sprayed, the diffusion of the sprayed liquid to the parts of the wafer that do not need to be cleaned can be reduced, making the rest of the surface of the wafer clean and making the wiping and cleaning of the wafer targeted.

[0028] Refer to Figure 4 and Figure 5 As shown, a liftable and adjustable bracket 2 is provided at the top of the positioning plate 14. Specifically, it can be driven by a multi-axis module formed by the X and Y axes in the prior art to achieve the adjustment of the bracket 2 in the vertical and horizontal directions; Rotating columns 21 with the same size specifications are installed at the four corners of the bracket 2. A motor is also installed on the bracket 2, and any one of the rotating columns 21 is connected to the output shaft of the motor and can form a continuous rotational movement; A wiping belt 22 is tightly sleeved between the four rotating columns 21. Since any one of the rotating columns 21 can rotate driven by the motor, at this time, the wiping belt 22 on the four rotating columns 21 can form a continuous transmission in a single direction; It should be noted that the height positions of the two rotating columns 21 located below are the same, and the distance between the two rotating columns 21 can be adjusted according to actual processing requirements, aiming to ensure that the length of the wiping belt 22 between these two rotating columns 21 is slightly longer than the positioning point / dirt on the wafer to be wiped; During use: After spraying the cleaning liquid at the positioning point, through the continuous transmission of the wiping belt 22, the wiping belt 22 between the two rotating columns 21 located below can contact and continuously wipe the dirt attached to the positioning point on the wafer, so that the dirt detaches from the wafer and adheres to the outer surface of the wiping belt 22, thereby forming automatic wiping and cleaning of the wafer; Moreover, the wiping belt 22 of the present application has a continuous conveyance in a single direction. This continuous transmission avoids the possible damage caused by the back-and-forth wiping of dirt in the prior art. At the same time, the dirt on the wafer always contacts the relatively clean cleaning surface of the wiping belt 22, reducing the situation where the dirt on the wiping belt 22 adheres to the wafer again, improving the cleaning efficiency and quality, and reducing the risk of damage to the wafer during the cleaning process.

[0029] Reference Figure 4 and Figure 5 As shown, the wiping belt 22 is made of rubber, and the material can be silicone rubber, fluororubber, etc., which has characteristics such as softness and corrosion resistance. The wiping belt 22 is closed at both ends and tightly sleeved between the four rotating columns 21, which greatly improves the fitting degree between the wiping belt 22 and the wafer surface, can uniformly remove the pollutants at the positioning place, and can reduce the damage to the wafer surface.

[0030] Reference Figure 4 and Figure 5 As shown, a cleaning tank 24 is also installed on the bracket 2, and cleaning water for cleaning the wiping belt 22 is injected into the cleaning tank 24 in advance; a positioning column 241 is rotatably installed in the cleaning tank 24; among them, the positioning column 241 is configured to limit the wiping belt 22 between the two rotating columns 21 located above, so that this part of the wiping belt 22 forms a "V" shape and sinks into the cleaning liquid in the cleaning tank 24. Figure 5 The gray filling in the figure indicates the cleaning liquid; During use: On the basis of the continuous single-direction conveyance of the above-mentioned wiping belt 22, the wiping belt 22 can continuously enter the cleaning tank 24 and contact and clean with the cleaning liquid in the cleaning tank 24 to clean the dirt and cleaning liquid attached to the wiping belt 22, ensuring that the outer surface of the wiping belt 22 that contacts the wafer positioning point after the wiping belt 22 exits the cleaning tank 24 is always clean, improving the wiping effect of the wiping belt 22 on the wafer, enabling the wiping belt 22 to have the ability to continuously wipe a batch of wafers, and the wiping efficiency of a batch of wafers.

[0031] Reference Figure 5 As shown, a drying strip 242 that fits the surface of the wiping belt 22 is also installed in the cleaning tank 24. The drying strip 242 can be a strip made of plastic. Two drying strips 242 can be provided and contact the outer surface and the inner surface of the wiping strip at the same time. The drying strip 242 is entirely above the liquid level, and it is used to remove the residual liquid on the surface of the wiping belt 22; During use: As the wiping belt 22 is continuously conveyed, and before the wiping belt 22 is cleaned and removed from the cleaning tank 24, the residual liquid on the outer surface and the inner surface of the wiping belt 22 can be scraped off by the drying strip 242. While reducing the cleaning liquid being carried out of the cleaning tank 24, it also makes the surface of the wiping belt 22 relatively dry after exiting the cleaning tank 24, ensuring the wiping effect of the wiping belt 22 on the dirt at the wafer positioning point subsequently.

[0032] Reference Figure 4 As shown, a water inlet pipe and a water outlet pipe are connected to the bottom of the cleaning tank 24, and the water inlet pipe and the water outlet pipe are connected to an external water pump through a hose. The water pump realizes the power for the liquid circulation and replacement in the cleaning tank 24, ensuring that the cleaning liquid in the cleaning tank 24 is always in a relatively clean state and improving its cleaning effect on the continuously input wiping belt 22.

[0033] Refer to Figure 4 、 Figure 6 and Figure 7 As shown, installation grooves 3 are provided at the bottoms of the adjacent ends of the two positioning plates 14. The installation grooves 3 are arranged along the width direction of the positioning plates 14. A cylindrical water removal sponge 31 is embedded in the installation grooves 3 for adsorbing residual liquid droplets on the surface of the wafer. Besides the sponge material, fiber cloth and other materials can also be used; During use: After the two positioning plates 14 move towards each other and are located above the wafer, the water removal sponge 31 on the positioning plates 14 will contact the top surface of the wafer. After the wafer is wiped, the two positioning plates 14 will move away from each other. During this process, the water removal sponge 31 on the positioning plates 14 will wipe the positioning area (i.e., the cleaning area) of the wafer to wipe off the residual cleaning liquid in this area and absorb the excess liquid through the characteristics of the sponge material, so as to make the surface of the wafer relatively dry and reduce the difficulty of subsequent processing.

[0034] Refer to Figure 4 、 Figure 6 、 Figure 7 、 Figure 8 and Figure 9 As shown, a flat cut 311 is provided on the surface of the water removal sponge 31. A shaft rod rotatably connected to the positioning plate 14 is coaxially installed inside the water removal sponge 31; A servo motor 32 is also installed on the side of the positioning plate 14; Either end of the shaft rod extends out of the side of the positioning plate 14 and is connected to the output shaft of the servo motor 32. Through the action of the servo motor 32, the water removal sponge 31 on the shaft rod can be driven to rotate and adjust; During use: Refer to Figure 4 and Figure 8 As shown, before adjusting the two positioning plates 14 to move towards each other and above the wafer, the water removal sponge 31 can be controlled to rotate by the servo motor 32 first to adjust the orientation of the flat cut 311 of the water removal sponge 31 so that the flat cut 311 faces the wafer in the placement groove 111; Subsequently, during the process of the two positioning plates 14 moving towards each other, since the flat cut 311 of the water removal sponge 31 faces downwards, the water removal sponge 31 will not scrape or contact the dirt on the fixture table 11 or the wafer during the transverse movement with the positioning plate 14, ensuring the cleanliness of the surface of the water removal sponge 31; Refer to Figure 4 and Figure 9 As shown, after the wiping treatment of the dirt on the wafer surface is completed, the water removal sponge 31 can be controlled to rotate 180° by the servo motor 32 so that the flat cut 311 of the water removal sponge 31 changes from facing downwards to facing upwards. At this time, the surface of the water removal sponge 31 opposite to the flat cut 311 will contact and fit with the wafer surface. When the two positioning plates 14 move away from each other, the water removal sponge 31 can be used to continuously contact and wipe the surface of the wafer positioning area to wipe off the residual cleaning liquid at the positioning area to ensure dryness; Generally speaking, through the design of the water removal sponge 31 and its upper flat cut 311, and through the variable adjustment ability of the water removal sponge 31, when the water removal sponge 31 moves with the positioning plate 14 above the un-wiped wafer, the water removal sponge 31 will not contact the dirt on the fixture table 11 or the wafer; conversely, when the water removal sponge 31 moves out with the positioning plate 14 above the wiped wafer, the water removal sponge 31 can contact the surface of the wafer after cleaning and wiping to remove the residual cleaning liquid on the surface.

[0035] Referring to Figure 7 , Figure 8 and Figure 9 As shown, a plurality of air ducts 33 are also installed on the top of the positioning plate 14. The air ducts 33 are interconnected with each other and are connected to an external air pump through a hose, so that the plurality of air ducts 33 have the ability to continuously discharge air. A temperature adjustment device composed of heating wires can also be connected between the air pump and the air ducts 33, so that the air flow output by the air ducts 33 has a certain temperature, which is convenient for enhancing the subsequent air drying efficiency of the water removal sponge 31, and the air outlet of the air ducts 33 is located in the installation groove 3; During use: As Figure 8 shown, after the water removal sponge 31 wipes the surface of the previous wafer, the surface of the water removal sponge 31 opposite to the flat cut 311 will be relatively wet. The air flow continuously output by the air ducts 33 will continuously be injected into the installation groove 3 and form an air drying effect on the wet surface of the water removal sponge 31, which is convenient for the water removal effect of the dried water removal sponge 31 on the cleaning liquid on the surface of the next wafer; In this way, the continuous wiping ability of the water removal sponge 31 in the batch wafer processing is improved, as well as the drying effect of the wafer surface during the continuous wiping process; At the same time, as Figure 9 shown, a channel for gas flow is formed between the water removal sponge 31 and the inner wall of the installation groove 3. The gas can cover all surfaces of the water removal sponge 31 during the gas flow process, further enhancing the drying effect of the water removal sponge 31; and when the water removal sponge 31 contacts and wipes the wafer surface, the gas continuously injected by the air ducts 33 can also flow through this channel and blow towards the wafer surface wiped by the water removal sponge 31, accelerating the evaporation of the liquid film on the wiped wafer surface through gas blowing.

[0036] 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. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A wafer wiping device, including a base (1), characterized in that: A fixture table (11) is installed on the base (1), and a placement groove (111) is provided at the top of the fixture table (11) for carrying the wafer; An air cavity (112) is formed in the fixture table (11), and a plurality of air ports (113) communicating with the air cavity (112) are provided on the bottom surface of the placement groove (111); An air injection pipe (12) and an air extraction pipe (13) communicating with the inside of the air cavity (112) are installed on the side of the fixture table (11) for selectively controlling the air flow change in the air cavity (112); Two positioning plates (14) are slidably installed on the base (1), both located above the fixture table (11), for restricting the wafer from separating from the placement groove (111).

2. The wafer wiping device according to claim 1, wherein: A cleaning window penetrates through the positioning plate (14) for exposing the area of the wafer to be cleaned; A cleaning liquid spray head (23) is installed on the top of each of the two positioning plates (14). The cleaning liquid spray head (23) is located at the adjacent end of the two positioning plates (14) for spraying cleaning liquid onto the surface of the area of the wafer to be cleaned.

3. The wafer wiping device according to claim 2, wherein: A bracket (2) that can be adjusted in height is provided at the top end of the positioning plate (14); Rotating columns (21) are installed at the four corners of the bracket (2), and any one of the rotating columns (21) can form a continuous rotational movement; A wiping belt (22) is tightly sleeved between the four rotating columns (21); 4. The wafer wiping device according to claim 3, wherein: The wiping belt (22) is made of rubber material, and its head and tail are closed and tightly sleeved between the four rotating columns (21); 5. The wafer wiping device according to claim 3 or 4, characterized in that: A cleaning box (24) is also installed on the bracket (2); A positioning column (241) is rotatably installed in the cleaning box (24); Among them, the positioning column (241) is used to prevent the wiping belt (22) between the two rotating columns (21) located above from sinking into the cleaning liquid in the cleaning box (24); 6. The wafer wiping device according to claim 5, wherein: A drying strip (242) that fits the surface of the wiping belt (22) is also installed in the cleaning box (24), which is used to remove the residual liquid on the surface of the wiping belt (22); 7. The wafer wiping device according to claim 5, wherein: The bottom of the cleaning box (24) is communicated with a water inlet pipe and a water outlet pipe, and the water inlet pipe and the water outlet pipe are communicated with an external water pump through a hose to realize the liquid circulation and replacement in the cleaning box (24); 8. The wafer wiping device according to claim 3 or 2, characterized in that: Installation grooves (3) are opened at the bottom of the adjacent ends of the two positioning plates (14), and cylindrical water-absorbing sponges (31) are embedded in the installation grooves (3) for adsorbing the residual liquid droplets on the surface of the wafer; 9. The wafer wiping device according to claim 8, characterized in that: A flat cut (311) is provided on the surface of the water-absorbing sponge (31), and a shaft rod rotatably connected to the positioning plate (14) is coaxially installed inside the water-absorbing sponge (31); A servo motor (32) is also installed on the side of the positioning plate (14); Either end of the shaft rod extends out of the side of the positioning plate (14) and is connected to the output shaft of the servo motor (32); 10. The wafer wiping device according to claim 9, wherein: A plurality of air guide pipes (33) are also installed on the top of the positioning plate (14), and the air outlet of the air guide pipe (33) is located in the installation groove (3).

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