A wafer wiping device

Abstract

The present invention relates to the field of silicon wafer processing technology, and specifically to a wafer wiping device, comprising a base, a jig table is installed on the base, and a placement groove is provided on the top of the jig table for carrying the wafer; 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 installed on the side of the jig table; two positioning plates are slidably installed on the base; through the setting of the air ports, the air flow can be continuously blown to the bottom end face of the wafer when the air port is blown according to the change of the air flow in the air cavity, and the bottom end face of the wafer is continuously removed during the whole process; when the air port changes from blowing to inlet, negative pressure will be formed at the air port and adsorption will be formed on the bottom end face of the cleaned wafer, so that the wafer is fixed in the placement groove, avoiding damage caused by the existing clamp to the wafer when it 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.

Description

Technical Field

[0001] The present 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, these marking points may be blocked by dirt, causing these marks to become unclear, affecting the identification and tracking accuracy of the wafer. Usually, the dirt at the marking points is wiped clean after the wafer is positioned.

[0003] Existing wafer positioning devices mostly use a pressure block combined with a rubber pad to fix the wafer on the base. Although this method avoids direct contact between the pressure block and the wafer surface to a certain extent, thereby protecting the surface quality of the wafer, it still has the following shortcomings in actual use:

[0004] First, the adhesive pad is in direct contact with the top surface of the wafer. During batch processing, the adhesive pad frequently contacts different wafers, which can easily accumulate impurities and even form lumps. These impurities may directly damage the wafer surface during the subsequent clamping process.

[0005] 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

[0006] The present invention provides a wafer wiping device that can clean the bottom surface of a wafer before positioning and clamping the wafer, and form an adsorption clamping for the wafer after cleaning. The specific scheme is as follows:

[0007] A wafer wiping device includes a base, a jig table is installed on the base, and 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 interior of the air cavity are installed on the side of the jig table for selectively controlling the change of airflow in the air cavity; two positioning plates are slidably installed on the base, both located above the jig table, for limiting the wafer from leaving the placement groove.

[0008] Furthermore, a cleaning window is passed through the positioning plate to expose the area of the wafer 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.

[0009] 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; a wiping belt is tightly sleeved between the four rotating columns.

[0010] Furthermore, the wiping belt is made of rubber, is closed at both ends and is tightly sleeved between the four rotating cylinders.

[0011] Furthermore, a cleaning box is installed on the bracket; a positioning column is rotatably installed in the cleaning box; wherein the positioning column is used to limit the wiping belt located between the two rotating columns above to sink into the cleaning liquid in the cleaning box.

[0012] Furthermore, a drying strip is installed in the cleaning box and is in contact with the surface of the wiping belt, and is used to remove residual liquid on the surface of the wiping belt.

[0013] Furthermore, a water inlet pipe and a water outlet pipe are connected to the bottom of the cleaning box, and the water inlet pipe and the water outlet pipe are connected to an external water pump through a hose to realize the circulation and replacement of the liquid in the cleaning box.

[0014] Furthermore, the bottoms of the adjacent ends of the two positioning plates are each provided with a mounting groove, and a cylindrical dewatering sponge is embedded in the mounting groove to absorb residual droplets on the surface of the wafer.

[0015] Furthermore, a flat cut is provided on the surface of the dewatering sponge, and a shaft rod rotatably connected to the positioning plate is coaxially installed inside the dewatering sponge; a servo motor is also installed on the side of the positioning plate; either end of the shaft rod extends along the side of the positioning plate and is connected to the output shaft of the servo motor.

[0016] Furthermore, a plurality of air ducts are installed on the top of the positioning plate, and the air outlets of the air ducts are located in the installation grooves.

[0017] Compared with the prior art, the present invention can achieve at least the following beneficial effects:

[0018] The device is provided with an air port, which can adjust the airflow in the air cavity so that when the air port is blown, the airflow will continuously blow toward the bottom end surface of the wafer and be discharged from the gap between the wafer and the placement groove. The whole process forms a continuous impurity removal process on the bottom end surface of the wafer.

[0019] When the air inlet changes from blasting to air intake, negative pressure will be formed at the air inlet and adsorption will be formed on the bottom end surface of the cleaned wafer, so that the wafer is fixed in the placement slot, avoiding the damage caused by the existing fixture when clamping the wafer, and facilitating the staff to wipe the dirt on the marking point of the wafer adsorbed and fixed in the placement slot. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort. Among them:

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0022] Figure 2 This is a structural schematic diagram of the wafer of the present invention being located in a placement slot.

[0023] Figure 3 Schematic diagram of the structure of the air cavity of the present invention.

[0024] Figure 4 For the present invention Figure 2 Schematic diagram of the local structure in.

[0025] Figure 5 Schematic diagram of the internal structure of the cleaning box of the present invention.

[0026] Figure 6 This is a schematic diagram of the bottom structure of the positioning plate of the present invention.

[0027] Figure 7 This is a schematic diagram of the top structure of the positioning plate of the present invention.

[0028] Figure 8 It is a schematic diagram of the cross-sectional structure of the positioning plate of the present invention.

[0029] Figure 9 This is a schematic diagram of another state of the water blowing sponge of the present invention.

[0030] The accompanying drawings are numerals as follows:

[0031] 1. Base; 11. Fixture table; 111. Placement slot; 112. Air cavity; 113. Air port; 12. Air injection pipe; 13. Air extraction pipe; 14. Positioning plate;

[0032] 2. Bracket; 21. Rotating column; 22. Wiping belt; 23. Cleaning liquid nozzle; 24. Cleaning box; 241. Positioning column; 242. Drying strip;

[0033] 3. Mounting slot; 31. Water-removing sponge; 311. Flat incision; 32. Servo motor; 33. Air duct. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0035] Please refer to Figure 1 and Figure 2 As 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 connected to an external air pump through a one-way valve hose respectively, for selectively controlling the air flow change in the air cavity 112, and forming 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 by a slide rail, both of which are located above the jig table 11, and 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;

[0036] 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 placed 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. This prevents the positioning plate 14 from scratching the top surface of the wafer in the placement groove 111 during the lateral movement.

[0037] During 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 airflow that is continuously injected into the air cavity 112. 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 into the bottom end surface of the positioning plate 14. 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 impurity removal process on the bottom end surface of the wafer.

[0038] Subsequently, the external air pump stops 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 adsorption is formed with the bottom end surface of the cleaned wafer, so that the wafer is fixed in the placement groove 111, avoiding the damage caused by the existing clamp when clamping and fixing the wafer, 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 position) will not deflect or move during the wiping process.

[0039] Reference Figure 2 、 Figure 4 and Figure 7 As shown, a cleaning window is passed through the positioning plate 14. After the positioning plate 14 is located above the wafer, the cleaning window is used to expose the wafer area to be cleaned, and the cleaning area is the marked point of the wafer; a cleaning liquid nozzle 23 is installed on the top of each of the two positioning plates 14. The cleaning liquid nozzle 23 is located at the adjacent ends of the two positioning plates 14. The cleaning liquid nozzle 23 is externally connected to the pump body and is used for the cleaning liquid nozzle 23 to spray cleaning liquid onto the surface of the wafer area to be cleaned. The cleaning liquid can be SC1 solution, hydrofluoric acid, deionized water, etc.

[0040] During use: After the wafer is adsorbed and fixed, and the positioning plate 14 is located above the wafer, the cleaning liquid can be sprayed to the cleaning area circled by the cleaning window through the cleaning liquid nozzle 23, and then the dirt at the marked point can be cleaned manually or by equipment to improve the wiping quality;

[0041] The setting of the cleaning window on the positioning plate 14 only exposes the marked 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, it can reduce the spread of the sprayed liquid to the parts of the wafer that do not need to be cleaned, so that the rest of the wafer surface is clean and the wiping cleaning of the wafer is targeted.

[0042] Reference Figure 4 and Figure 5 As shown, a lifting and lowering adjustable bracket 2 is provided at the top of the positioning plate 14, which can be driven by a multi-axis module formed by X and Y axes in the prior art, so as to realize the adjustment of the bracket 2 in the vertical and horizontal directions; rotating columns 21 with the same size and specifications are installed at the four corners of the bracket 2, and a motor is also installed on the bracket 2, and any rotating column 21 is connected to the motor output shaft and can form a continuous rotation movement; a wiping belt 22 is tightly wrapped between the four rotating columns 21. Since any rotating column 21 can be rotated by the motor, the wiping belts 22 on the four rotating columns 21 can form a continuous transmission in a single direction.

[0043] It is worth noting that the two rotating cylinders 21 at the bottom are at the same height, and the distance between the two rotating cylinders 21 can be adjusted according to actual processing requirements, in order to ensure that the length of the wiping belt 22 between the two rotating cylinders 21 is slightly larger than the wafer positioning point / dirt to be wiped;

[0044] During use: After spraying the cleaning liquid at the positioning point, the wiping belt 22 can be continuously transported. The wiping belt 22 located between the two rotating cylinders 21 below can contact and continuously wipe the dirt attached to the positioning point on the wafer, so that the dirt is separated from the wafer and attached to the outer surface of the wiping belt 22, thereby achieving automatic wiping and cleaning of the wafer;

[0045] In addition, the wiping belt 22 of the present application has continuous transportation in a single direction. This continuous transportation avoids the damage that may be caused by wiping dirt back and forth in the prior art. At the same time, the dirt on the wafer is always in contact with 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.

[0046] 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., and has the characteristics of softness and corrosion resistance. The wiping belt 22 is closed at both ends and tightly wrapped between the four rotating cylinders 21, which greatly improves the fit between the wiping belt 22 and the wafer surface, can evenly remove pollutants at the positioning position, and can reduce its damage to the wafer surface.

[0047] Reference Figure 4 and Figure 5 As shown, a cleaning box 24 is also installed on the bracket 2, and cleaning water for cleaning the wiping belt 22 is pre-injected into the cleaning box 24; a positioning column 241 is rotatably installed in the cleaning box 24; wherein, the positioning column 241 is configured to limit the wiping belt 22 located between the two rotating columns 21 above, so that this part of the wiping belt 22 forms a "V" shape and is recessed into the cleaning liquid in the cleaning box 24, Figure 5 The medium grey fill indicates the cleaning liquid;

[0048] During use: On the basis of the continuous single-direction conveying of the above-mentioned wiping belt 22, the wiping belt 22 can continuously enter the cleaning box 24 and contact with the cleaning liquid in the cleaning box 24 for cleaning, so as to clean the dirt and cleaning liquid attached to the wiping belt 22, and ensure that the outer surface of the wiping belt 22 that contacts the wafer positioning point after the wiping belt 22 is output from the cleaning box 24 is always clean, thereby improving the wiping effect of the wiping belt 22 on the wafer, and enabling the wiping belt 22 to have the ability to continuously wipe batches of wafers, and the wiping efficiency of batches of wafers.

[0049] Reference Figure 5As shown, a drying strip 242 is installed in the cleaning box 24 and is in contact with the surface of the wiping belt 22. The drying strip 242 can be a strip made of plastic material. 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 located above the liquid surface as a whole and is used to remove residual liquid on the surface of the wiping belt 22.

[0050] During use: As the wiping belt 22 is continuously transported, and after the wiping belt 22 is cleaned and before it is moved out of the cleaning box 24, the residual liquid on the outer and inner surfaces of the wiping belt 22 can be scraped off by the drying strip 242, thereby reducing the amount of cleaning liquid carried away from the cleaning box 24 and making the surface of the wiping belt 22 relatively dry after being moved out of the cleaning box 24, thereby ensuring the subsequent wiping effect of the wiping belt 22 on dirt at the wafer positioning points.

[0051] Reference Figure 4 As shown, the bottom of the cleaning box 24 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. The water pump realizes the power of liquid circulation and replacement in the cleaning box 24, ensuring that the cleaning liquid in the cleaning box 24 is always in a relatively clean state, thereby improving its cleaning effect on the continuously input wiping belt 22.

[0052] Reference Figure 4 、 Figure 6 and Figure 7 As shown, the bottoms of the adjacent ends of the two positioning plates 14 are each provided with a mounting groove 3, which is arranged along the width direction of the positioning plate 14. A cylindrical dewatering sponge 31 is embedded in the mounting groove 3 to absorb residual droplets on the surface of the wafer. In addition to sponge materials, fiber cloth and other materials can also be used;

[0053] During use: After the two positioning plates 14 move toward each other and are located above the wafer, the dewatering sponge 31 on the positioning plate 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 dewatering sponge 31 on the positioning plate 14 will wipe the positioning area of the wafer (i.e., the cleaning area) to wipe off the residual cleaning liquid in this area, and absorb excess liquid through the characteristics of the sponge material, thereby making the wafer surface relatively dry and reducing the difficulty of subsequent processing.

[0054] Reference Figure 4 、 Figure 6 、 Figure 7 、 Figure 8 and Figure 9 As shown, a flat cutout 311 is provided on the surface of the dewatering sponge 31. A shaft rotatably connected to the positioning plate 14 is coaxially mounted inside the dewatering sponge 31. A servo motor 32 is also mounted on the side of the positioning plate 14. Either end of the shaft extends out from the side of the positioning plate 14 and is connected to the output shaft of the servo motor 32. The action of the servo motor 32 can drive the dewatering sponge 31 on the shaft to rotate and adjust.

[0055] When using: Combined Figure 4 and Figure 8 As shown, before adjusting the two positioning plates 14 to move toward each other and above the wafer, the desiccant sponge 31 can be rotated by the servo motor 32 to adjust the direction of the flat cutout 311 of the desiccant sponge 31 so that the flat cutout 311 faces the wafer in the placement groove 111. Subsequently, during the movement of the two positioning plates 14 toward each other, since the flat cutout 311 of the desiccant sponge 31 faces downward, the desiccant sponge 31 will not scratch or contact dirt on the jig table 11 or the wafer during the lateral movement of the positioning plates 14, thereby ensuring that the surface of the desiccant sponge 31 is clean.

[0056] Combine Figure 4 and Figure 9 As shown, after the wafer surface is cleaned, the dewatering sponge 31 can be controlled by the servo motor 32 to rotate 180 degrees so that the flat cutout 311 of the dewatering sponge 31 changes from facing downward to facing upward. At this time, the surface of the dewatering sponge 31 facing away from the flat cutout 311 is in contact with the wafer surface. When the two positioning plates 14 move away from each other, the dewatering sponge 31 can continue to contact and wipe the surface of the wafer positioning area to wipe off the cleaning liquid remaining in the positioning area to ensure dryness.

[0057] In general, the above scheme uses the design of the dewatering sponge 31 and the flat cutout 311 thereon, and the variable adjustment ability of the dewatering sponge 31, so that when the dewatering sponge 31 moves with the positioning plate 14 to above the unwiped wafer, the dewatering sponge 31 will not come into contact with the fixture table 11 or the dirt on the wafer; on the contrary, when the dewatering sponge 31 moves with the positioning plate 14 to above the wiped wafer, the dewatering sponge 31 can come into contact with the surface of the cleaned wafer to remove the cleaning liquid remaining on the surface.

[0058] Reference Figure 7 、 Figure 8 and Figure 9 As shown, a plurality of air ducts 33 are further installed on the top of the positioning plate 14. The air ducts 33 are interconnected and connected to an external air pump through a hose, so that the plurality of air ducts 33 have a continuous air discharge capability. A temperature control device composed of an electric heating wire can also be connected between the air pump and the air duct 33 to ensure that the air flow output by the air duct 33 has a certain temperature, which is convenient for enhancing the subsequent drying efficiency of the water removal sponge 31. The air outlet of the air duct 33 is located in the mounting slot 3;

[0059] When using: Figure 8 As shown, after the dewatering sponge 31 wipes the surface of the previous wafer, the surface of the dewatering sponge 31 opposite the flat cutout 311 will be relatively wet. The airflow continuously output by the air duct 33 will be continuously injected into the mounting slot 3 and directly dry the wet surface of the dewatering sponge 31, thereby facilitating the dewatering sponge 31 to remove the cleaning liquid from the next wafer surface after drying.

[0060] This reciprocating process improves the continuous wiping capability of the dewatering sponge 31 in batch wafer processing, and the drying effect of the wafer surface during the continuous wiping process;

[0061] At the same time, if Figure 9 As shown, a channel for gas circulation is formed between the dewatering sponge 31 and the inner wall of the mounting groove 3. During the gas circulation process, the entire surface of the dewatering sponge 31 can be covered, thereby further improving the drying effect of the dewatering sponge 31. Moreover, when the dewatering sponge 31 contacts and wipes the wafer surface, the gas continuously injected by the air duct 33 can also flow through this channel and blow toward the wafer surface after being wiped by the dewatering sponge 31, thereby accelerating the evaporation of the liquid film on the wafer surface after wiping by the gas blowing.

[0062] 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 the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A wafer wiping device, comprising a base (1), characterized in that: A fixture table (11) is mounted on the base (1), and a placement groove (111) is provided on the top of the fixture table (11) for carrying wafers; 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 interior of the air cavity (112) are installed on the side of the fixture table (11) for selectively controlling the change of air flow in the air cavity (112); Two positioning plates (14) are slidably mounted on the base (1), both located above the fixture table (11) and used to prevent the wafer from leaving the placement slot (111); The positioning plate (14) is penetrated by a cleaning window for exposing the wafer area to be cleaned; A cleaning liquid nozzle (23) is installed on the top of each of the two positioning plates (14), and the cleaning liquid nozzle (23) is located at adjacent ends of the two positioning plates (14) and is used to spray cleaning liquid onto the surface of the wafer area to be cleaned; The top end of the positioning plate (14) is provided with a bracket (2) that can be raised and lowered; The four corners of the bracket (2) are each equipped with a rotating column (21), and any rotating column (21) can form a continuous rotating motion; A wiping belt (22) is tightly sleeved between the four rotating columns (21).

2. The wafer wiping device according to claim 1, wherein: The wiping belt (22) is made of rubber, is closed at both ends and is tightly sleeved between the four rotating columns (21).

3. The wafer wiping device according to claim 1 or 2, wherein: A cleaning box (24) is also mounted on the bracket (2); A positioning column (241) is rotatably mounted in the cleaning box (24); The positioning column (241) is used to limit the wiping belt (22) located between the two rotating columns (21) above from being sunken into the cleaning liquid in the cleaning box (24).

4. The wafer wiping device according to claim 3, wherein: A wiping strip (242) is also installed in the cleaning box (24) and is in contact with the surface of the wiping belt (22). The wiping strip (242) is used to remove residual liquid on the surface of the wiping belt (22).

5. The wafer wiping device according to claim 3, wherein: The bottom of the cleaning box (24) is connected to 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, so as to realize the circulation and replacement of the liquid in the cleaning box (24).

6. The wafer wiping device according to claim 1, wherein: The bottoms of the adjacent ends of the two positioning plates (14) are each provided with a mounting groove (3), and a cylindrical dewatering sponge (31) is embedded in the mounting groove (3) for absorbing residual droplets on the surface of the wafer.

7. The wafer wiping device according to claim 6, wherein: The surface of the dewatering sponge (31) is provided with a flat cutout (311), and a shaft rotatably connected to the positioning plate (14) is coaxially mounted inside the dewatering sponge (31); A servo motor (32) is also installed on the side of the positioning plate (14); Either end of the shaft extends along the side of the positioning plate (14) and is connected to the output shaft of the servo motor (32).

8. The wafer wiping device according to claim 7, wherein: A plurality of air ducts (33) are also installed on the top of the positioning plate (14), and the air outlets of the air ducts (33) are located in the installation groove (3).

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