Wafer thinning equipment

Abstract

The invention relates to wafer thinning equipment, which comprises a grinding module, the wafer transmission device comprises a vacuum chuck and a manipulator, the vacuum chuck is used for adsorbing the wafer received from the grinding module, a water film is attached to the surface of the wafer, and the manipulator is provided with a clamping jaw used for clamping the wafer from the vacuum chuck and carrying the wafer; the manipulator is configured to enable the wafer to be vertically away from the vacuum chuck by a distance of 200 microns to 400 microns, and a water film is not broken within the distance; then moving the wafer parallel to the contact surface of the wafer and the vacuum chuck so as to reduce the area of a water film between the wafer and the vacuum chuck; and further, the wafer is far away from the vacuum chuck to break the water film and take away the wafer. The water film tension is effectively reduced when the wafer is clamped from the vacuum chuck, and the polishing manipulator and the wafer can be protected.

Description

[0001] This application is a divisional application of the invention application with the application number 202411959834.5 and the title "Wafer Processing Method and Wafer Processing Apparatus" filed on December 30, 2024. Technical Field

[0002] The present invention relates to the field of semiconductor manufacturing; more specifically, the present invention relates to a wafer thinning device. Background Art

[0003] The thinning process of a wafer in a thinning equipment station is as follows: The wafer is transported by a transfer component to a grinding module, and after being ground and thinned, it is then transported by the transfer component and picked up by a manipulator and transferred to the next station. The transfer component can be a vacuum chuck to adsorb the wafer, and the manipulator can be a jaw to hold and transport.

[0004] During the process of the wafer being returned after thinning, a cleaning operation is performed on the back of the wafer. After cleaning, a water film adheres to the back of the wafer, and a tension is generated between the water film and the chuck of the transfer component. When the manipulator holds and lifts the wafer, the water film tension is destroyed, resulting in a phenomenon of vibration and tremor. The irregular vibration of the manipulator makes the contact part between the wafer and the jaw prone to damage and has a greater impact on the service life of the manipulator jaw. Summary of the Invention

[0005] In view of this, the present invention provides a wafer thinning device, thereby solving or at least alleviating one or more of the above problems and other problems existing in the prior art.

[0006] To achieve the foregoing object, a first aspect of the present invention provides a wafer thinning device, the wafer thinning device comprising: a grinding module including a grinding unit for grinding a wafer and a cleaning unit for cleaning the wafer; a wafer transfer device including a vacuum chuck and a manipulator, the vacuum chuck being configured to adsorb the wafer received from the grinding module, a water film adhering to the surface of the wafer, the manipulator having jaws for picking up the wafer from the vacuum chuck and transporting the wafer; the manipulator being configured to: move the wafer vertically away from the vacuum chuck by a distance of 200 μm to 400 μm, within which the water film does not break; then move the wafer parallel to the contact surface between the wafer and the vacuum chuck to reduce the area of the water film between the wafer and the vacuum chuck; and then move the wafer away from the vacuum chuck to break the water film and pick up the wafer.

[0007] Optionally, the vacuum chuck includes two rectangular vacuum chucks, the wafer covers the two rectangular vacuum chucks, and when the manipulator picks up the wafer, it inserts under the wafer, passes between the two rectangular vacuum chucks, and holds the wafer with the jaws.

[0008] Optionally, the vacuum chuck is made of porous ceramic material, and a gas channel is provided below the vacuum chuck. The gas channel communicates with the wafer surface through the porous ceramic to distribute gas to the wafer. The gas evaporates moisture to assist in reducing the water film area. The wafer transfer device decomposes the liquid tension and gradually and uniformly reduces the water film area according to the distribution amount and distribution speed of the gas.

[0009] Optionally, moving the wafer parallel to the contact surface between the wafer and the vacuum chuck includes: translating or swinging the wafer parallel to the contact surface between the wafer and the vacuum chuck.

[0010] Optionally, the wafer transfer device further includes a controller connected to the manipulator, and the controller controls the manipulator to perform the action of clamping the wafer.

[0011] Optionally, the manipulator includes a first set of jaws and a second set of jaws. The first set of jaws includes a first jaw and a second jaw arranged side by side, and the second set of jaws includes a third jaw and a fourth jaw arranged side by side. The first set of jaws and the second set of jaws can move relative to each other to clamp and transport the wafer.

[0012] Optionally, the wafer thinning equipment further includes an equipment front end module, which is arranged at the front end of the wafer thinning equipment and is used to realize the loading and unloading of wafers.

[0013] Optionally, the wafer thinning equipment further includes a post-processing unit for cleaning and drying the wafer, and the post-processing unit includes a horizontal brushing device.

[0014] Some technical solutions of the present invention effectively reduce the water film tension and alleviate the vibration and jitter at the end of the polishing manipulator jaws.

[0015] Some technical solutions of the present invention can further effectively reduce the scratches generated by the relative movement between the wafer and the polishing manipulator.

[0016] Some technical solutions of the present invention can further effectively extend the service life of the jaws of the manipulator. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] With reference to the accompanying drawings, the disclosure of the present invention will become more apparent. It should be understood that these drawings are only for illustrative purposes and are not intended to limit the scope of protection of the present invention. In the figures:

[0018] Figure 1 A schematic plan view of a wafer processing device is shown.

[0019] Figure 2 A top view schematic diagram of the polishing manipulator jaws in the wafer processing device is shown, and at the same time, the vacuum chuck and the wafer of the transfer assembly in the first positional relationship are shown.

[0020] Figure 3 schematically shows Figure 2 the water film between the wafer and the vacuum chuck of the transfer assembly in

[0021] Figure 4 shows a top view schematic diagram of the polishing robot gripper in the wafer processing apparatus, and at the same time shows the vacuum chuck and the wafer of the transfer assembly in the second positional relationship.

[0022] Figure 5 schematically shows Figure 4 the water film between the wafer and the chuck of the transfer assembly in

[0023] Figure 6 shows a top view schematic diagram of the polishing robot gripper in the wafer processing apparatus, and at the same time shows the vacuum chuck and the wafer of the transfer assembly in the third positional relationship.

[0024] Figure 7 shows a schematic flow chart of an embodiment of the wafer picking method according to the present invention.

[0025] Reference numerals: 1 - vacuum chuck; 2 - wafer; 3 - water film; 4 - robot; 5 - first set of grippers; 6 - second set of grippers; 7 - first gripper; 8 - second gripper; 9 - third gripper; 10 - fourth gripper; 20 - wafer processing apparatus; 21 - grinding module; 22 - polishing module; 23 - CMP and cleaning module; 24 - equipment front end module; 25 - wafer storage unit; 26 - first transfer unit; 27 - second transfer unit; 28 - third transfer unit; 29 - chemical mechanical polishing unit; 30 - post - processing unit; 31 - staging section; 32 - mobile buffer section; 33 - polishing robot; 34 - grinding unit; 35 - cleaning unit; 36 - fourth transfer unit; 37 - base; 38 - workbench; 39 - chuck; 41 - loading and unloading station; 42 - grinding robot; 43 - cleaning device. Detailed Description of the Invention

[0026] Referring to the accompanying drawings and specific embodiments, the structure, composition, characteristics, and advantages of the wafer thinning equipment of the present invention will be described by way of example below. However, all descriptions should not form any limitation to the present invention.

[0027] For any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature shown or implied in the respective drawings, the present invention still allows any combination or deletion to continue between these technical features (or their equivalents) without any technical obstacles. Therefore, it should be considered that these more embodiments according to the present invention are also within the scope of the present disclosure.

[0028] In addition, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature.

[0029] In this application, a wafer may also be referred to as a chip, silicon wafer, substrate, or base plate, etc., with the same meaning and practical function.

[0030] The wafer processing apparatus provided by the embodiments of the present disclosure is mainly applied to the back thinning of wafers, such as a wafer thinning device or a wafer thinning and polishing integrated machine. The back surface mentioned here refers to the side of the wafer without devices laid, generally the substrate, and the substrate material may be silicon, silicon oxide, silicon nitride, silicon carbide, sapphire, etc.

[0031] Figure 1 A schematic plan view of the wafer processing apparatus is shown.

[0032] As shown in the figure, the wafer processing apparatus 20 includes an equipment front-end module 24 (EFEM module), a CMP and cleaning module 23, a grinding module 21, etc. The CMP and cleaning module 23 specifically includes a polishing module 22, etc., where CMP represents chemical mechanical polishing.

[0033] The equipment front-end module 24 is used to realize the loading and unloading of wafers, and the equipment front-end module 24 is arranged at the front end of the wafer processing apparatus 20. The equipment front-end module 24 is a transition module for transporting wafers from the outside to the inside of the equipment machine table, used to realize the loading and unloading of wafers to achieve "dry loading and dry unloading" of wafers.

[0034] The grinding module 21 is used to grind and thin the wafer. The grinding may include rough grinding and fine grinding, and the grinding module 21 is arranged at the end of the wafer processing apparatus 20.

[0035] The polishing module 22 is used to perform chemical mechanical polishing on the wafer after the grinding is completed, and also has the function of transporting the wafer between these three modules (equipment front-end module 24, grinding module 21, and polishing module 22). The polishing module 22 is arranged between the equipment front-end module 24 and the grinding module 21.

[0036] It can be understood that Figure 1 The shown wafer processing apparatus is only an example. In other implementation manners, the polishing module 22 may also be omitted, and only the equipment front-end module 24 and the grinding module 21 are retained. In addition, the grinding module 21 may also include multiple grinding passes, such as 3 passes, 4 passes, 5 passes, etc. As long as these modified embodiments can realize the grinding and thinning of wafers, they should fall within the protection scope of this application.

[0037] The front-end module 24 of the device includes a wafer storage unit 25 and a first transfer unit 26. The wafer storage unit 25 is arranged on the front-end side of the wafer processing device 20, and the first transfer unit 26 is arranged between the wafer storage unit 25 and the polishing module 22 to realize the transfer of wafers between the wafer storage unit 25 and the polishing module 22.

[0038] The first transfer unit 26 may include a wafer pick-and-place manipulator. The wafer pick-and-place manipulator can rotate, extend, or fold and contract, and can also move along the transfer track. Here, the wafer pick-and-place manipulator is a dry manipulator for picking and placing dry and clean wafers. The wafer pick-and-place manipulator can take out the wafers to be processed from the wafer storage unit 25 and send them into the polishing module 22, and can also receive the processed wafers from the polishing module 22 and put them into the wafer storage unit 25.

[0039] The polishing module 22 may include a second transfer unit 27, a third transfer unit 28, a chemical mechanical polishing unit 29, and a post-processing unit 30. The second transfer unit 27, the chemical mechanical polishing unit 29, and the post-processing unit 30 respectively occupy the edges of the polishing module 22, and the third transfer unit 28 is located in the center.

[0040] Specifically, the second transfer unit 27 is located on one edge side in the polishing module 22 and is distributed along the length direction of the device, and can communicate with the front-end module 24 and the grinding module 21. The chemical mechanical polishing unit 29 is located on the other edge of the polishing module 22 and is adjacent to the grinding module 21 and the second transfer unit 27 respectively. The post-processing unit 30 is located on another edge of the polishing module 22 and is adjacent to the front-end module 24, the second transfer unit 27, and the chemical mechanical polishing unit 29 respectively. The third transfer unit 28 is close to the center of the polishing module 22 and is surrounded by the second transfer unit 27, the chemical mechanical polishing unit 29, and the post-processing unit 30 to realize the mutual transfer of wafers between the second transfer unit 27, the chemical mechanical polishing unit 29, and the post-processing unit 30. In the illustrated embodiment, the second transfer unit 27 may include a staging unit 31 and a mobile buffer unit 32 for staging wafers and transporting wafers. The staging unit 31 is arranged at a position close to the front-end module 24 for staging or transferring wafers. The mobile buffer unit 32 is arranged along the direction from the front-end module 24 to the grinding module 21 and can move bidirectionally.

[0041] In the illustrated embodiment, the third transfer unit 28 includes a polishing manipulator 33, and the polishing manipulator 33 is used to transfer the ground wafers from the mobile buffer unit 32 to the chemical mechanical polishing unit 29, transfer the polished wafers from the chemical mechanical polishing unit 29 to the post-processing unit 30, and transfer the cleaned wafers from the post-processing unit 30 to the staging unit 31.

[0042] After the wafer is taken out from the equipment front end module 24, it is transported to the grinding module 21 via the second transfer unit 27 for grinding; after the wafer is ground in the grinding module 21, it is transported to the chemical mechanical polishing unit 29 via the second transfer unit 27 and the third transfer unit 28 for polishing; after polishing and cleaning are completed, the wafer is then transported back to the equipment front end module 24 via the third transfer unit 28 and the second transfer unit 27.

[0043] The post-processing unit 30 is used for cleaning and drying the polished wafer, and may include a horizontal brushing device and a single-chamber cleaning device.

[0044] The grinding module 21 may include a grinding unit 34, a cleaning unit 35, and a fourth transfer unit 36. The grinding unit 34 is used to achieve wafer grinding and thickness measurement. As Figure 1 shown, the grinding unit 34 includes a base 37, a workbench 38 mounted on the base 37, a chuck 39 provided on the workbench 38, and a grinding wheel corresponding to the position of the chuck 39. The workbench 38 is used to carry the wafer and can rotate around its vertical central axis. As Figure 1 shown, in one embodiment, there are three chucks 39, which can rotate between the rough grinding station, the fine grinding station, and the loading and unloading station 41.

[0045] Two grinding wheels respectively achieve rough grinding and fine grinding. It can be understood that Figure 1 is only an example, and the number of chucks 39 and grinding wheels can also be other values. The cleaning unit 35 is used to achieve chuck 39 cleaning, grinding, and wafer cleaning. The fourth transfer unit 36 includes a grinding manipulator 42 for transferring the wafer. The grinding manipulator 42 refers to the manipulator used in the grinding module 21 and is used to transfer the wafer between the grinding unit 34 and the second transfer unit 27. Specifically, it is used to transfer the wafer between the chuck 39 corresponding to the loading and unloading station 41 and the mobile buffer 32. The grinding manipulator 42 takes the wafer from the mobile buffer 32 of the second transfer unit 27 and sends it into the grinding unit 34 for grinding. After grinding and cleaning are completed, the grinding manipulator 42 takes the wafer from the grinding unit 34 and then places it on the mobile buffer 32 for subsequent wafer transfer. The grinding manipulator 42 is internally provided with a pipeline that can be evacuated to achieve vacuum adsorption of the wafer. Alternatively, the grinding manipulator 42 can also be realized by a mechanism with jaws. In one embodiment, the grinding manipulator 42 can also drive the wafer to rotate.

[0046] As Figure 1 shown, in one embodiment of the present invention, the grinding module 21 further includes a cleaning device 43. The cleaning device 43 is installed on the base 37 of the grinding module 21, beside the workbench 38 and on the moving track of the grinding manipulator 42, and is used to clean the bottom surface of the wafer after grinding during the process of the grinding manipulator 42 transferring the wafer.

[0047] Figure 2 The figure shows a top view schematic diagram of the chuck of the polishing manipulator in the wafer processing apparatus, and at the same time shows the vacuum chuck 1 and the wafer 2 of the transfer component in the first positional relationship.

[0048] Wherein the transfer component can be, for example, the second transfer unit 27. In this figure, the vacuum chuck 1 of the transfer component can be Figure 1 the chuck on the second transfer unit 27 of the wafer processing apparatus 20 in the figure, and the manipulator 4 can be Figure 1 the polishing manipulator 33 of the wafer processing apparatus 20 in the figure. Since the wafer 2 has been cleaned by the cleaning apparatus 43, a water film adheres to the surface of the wafer.

[0049] As shown in the figure, the two rectangles shown by the dotted lines below the wafer 2 represent two vacuum chucks for adsorbing the wafer 2. The middle waist-shaped part does not contact the wafer 2. The vacuum chuck 1 in the figure is shown as a dotted line, indicating that it is located below the wafer 2; the manipulator 4 in the figure is shown as a solid line, indicating that it is located above the wafer 2.

[0050] The manipulator 4 includes a first set of chucks 5 and a second set of chucks 6. Optionally, the first set of chucks can be fixed and the second set of chucks can be movable, or vice versa. The first set of chucks 5 includes a first chuck 7 and a second chuck 8, and the second set of chucks 6 includes a third chuck 9 and a fourth chuck 10. The first chuck 7 and the second chuck 8 are connected together at the proximal end, and the third chuck 9 and the fourth chuck 10 are connected together at the proximal end. Clamping wheels are respectively installed at the distal ends of the first chuck 7, the second chuck 8, the third chuck 9, and the fourth chuck 10 for clamping the wafer 2. The clamping wheels can be set to be able to rotate respectively.

[0051] The first set of chucks 5 and the second set of chucks 6 can move relative to each other, so that the clamping wheels at the distal ends of the first chuck 7 and the second chuck 8 and the clamping wheels at the distal ends of the third chuck 9 and the fourth chuck 10 approach or move away from each other, thereby realizing the clamping and releasing of the wafer.

[0052] The relative movement of the first set of chucks 5 and the second set of chucks 6 can be achieved by a cylinder. For example, in one embodiment, one of the first set of chucks 5 and the second set of chucks 6 can be fixed on the arm (not shown) of the polishing manipulator. At the same time, a cylinder can be provided on the arm of the polishing manipulator. The cylinder block of the cylinder can be fixed to the arm of the polishing manipulator, and the piston rod is connected to the other of the first set of chucks 5 and the second set of chucks 6, thereby driving their relative movement. Here, the arm of the polishing manipulator is the frame relative to the first set of chucks 5 and the second set of chucks 6, and the relative movement of the two is defined by the cylinder. The cylinder can be replaced with an oil cylinder which is also a pressure cylinder.

[0053] Specifically, in one embodiment, a cylinder can be connected to the right end of the first set of jaws 5. The cylinder pushes the first set of jaws 5 to move, and the cylinder block of the cylinder can be fixedly connected to the right end of the second set of jaws 6. The first set of jaws 5 and the second set of jaws 6 form a wafer picking manipulator 4. The second set of jaws 6 is the fixed end, and the first set of jaws 5 is the movable end. In one embodiment, when picking up the wafer 2, the manipulator 4 is inserted under the wafer 2, passes between the two vacuum suction cups 1. After reaching the position, the first set of jaws 5 is pushed forward, and the second set of jaws 6 and the first set of jaws 5 clamp the wafer 2.

[0054] In this figure, it can be seen that the wafer 2 is adsorbed on the vacuum suction cup 1, and the wafer 2 is in a position completely covering the vacuum suction cup 1. At this position, the wafer 2 has been thinned at the grinding module 21 and cleaned at the cleaning device 43. The wafer 2 is not in a dry state, and there is a water film on the back of the wafer 2. The wafer 2 is transported from the grinding module 21 to the position to be picked up by the polishing manipulator 33 by the second transfer unit 27, and the polishing manipulator 33 transports it to the chemical mechanical polishing unit 29 of the polishing module 22 for polishing.

[0055] In this figure, the first set of jaws 5 and the second set of jaws 6 of the manipulator 4 (which is the polishing manipulator 33 in this embodiment) have clamped the wafer 2 through the first jaw 7, the second jaw 8, the third jaw 9, and the fourth jaw 10, and are in a state of about to perform a handling operation. In this state, the operation modes that the manipulator 4 can adopt include but are not limited to vertically moving the wafer 2 away from the vacuum suction cup 1 and laterally moving, vertically moving, swinging up and down, and concentrically rotating the wafer 2 relative to the vacuum suction cup 1 in the illustrated orientation.

[0056] It should be noted here that although two vacuum suction cups 1 are shown in the illustrated example and their shapes are square, in alternative embodiments, according to needs, the vacuum suction cup 1 can also be in other shapes such as circular, other polygonal, irregular shapes, etc. The number of vacuum suction cups 1 can also be other numbers, and the arrangement can also be different from that shown in the figure.

[0057] Figure 3 Schematically shows Figure 2 the water film between the wafer 2 and the vacuum suction cup 1 of the transfer assembly.

[0058] The figure shows the wafer 2, the vacuum suction cup 1 and the water film 3 therebetween. Since the wafer 2 covers the entire vacuum suction cup 1, the water film 3 is distributed on the entire surface of the vacuum suction cup 1. At this point, the area of the water film 3 is equal to the area of the vacuum suction cup 1. Below the vacuum suction cup 1 in the figure, its adjacent components are also shown, which are used to connect it to the second transfer unit, and will not be elaborated here.

[0059] The figure also schematically shows a third jaw 9 and a first jaw 7. It can be understood that according to the actual needs of wafer handling, in addition to Figure 2 and Figure 3 the clamping method, the manipulator 4 can also be clamped by jaws with a different number from that shown in the figure, such as but not limited to 3 jaws, 5 jaws or other numbers of jaws, etc.

[0060] Before the manipulator 4 transfers the wafer 2 from the vacuum chuck 1 of the second transfer unit 27, the wafer 2 is adsorbed by the vacuum chuck 1. Although they are closely attached, since the wafer is transferred to the vacuum chuck 1 without being dried after the cleaning process, there is still a thin water film formed between the wafer and the vacuum chuck.

[0061] When the manipulator 4 starts the transfer operation, the wafer can first reach the position as shown in Figure 3 by the manipulator 4 operating through each jaw. That is, as can be seen from the figure, when the manipulator 4 starts the transfer operation, the wafer 2 does not move horizontally, vertically, swing, rotate, etc. relative to the chuck as shown in Figure 2 , but only moves vertically away from the vacuum chuck 1 by a predetermined distance along the Z-axis upward, such as 200 μm to 400 μm, and more specifically, it can be 300 μm. When the wafer 2 is transferred upward by the manipulator 4 and moves away from the vacuum chuck 1 by the illustrated distance, the water film between the two does not break, and the water film 3 still exists. However, through this upward movement, it is possible to avoid scratches on the wafer caused by the residual crystal slag in the previous process when the wafer and the chuck move relatively, swing or rotate.

[0062] As can be seen from the figure, the wafer 2 is generally parallel to the vacuum chuck 1 and has moved upward by a certain distance from the position where it is attached to the vacuum chuck 1. Nevertheless, there is still a water film 3 between the wafer 2 and the vacuum chuck 1. Due to the surface tension of the water film, the thickness of the water film 3 has not reached the degree of rupture. In this case, it is avoided that the wafer 2 suddenly breaks the liquid tension and detaches from the vacuum chuck 1, causing the water film 3 to suddenly break; this sudden break is likely to cause vibration and trembling at the end of the jaws of the wafer and the manipulator 4, resulting in damage to the contact part between the wafer and the jaws of the manipulator 4 and affecting the service life of the polishing manipulator.

[0063] Figure 4 Shows a top view schematic of the jaws of the polishing manipulator in the wafer processing device, and at the same time shows the vacuum chuck 1 and the wafer 2 of the transfer component in the second positional relationship. Figure 5 Schematically shows Figure 4 the water film 3 between the wafer and the vacuum chuck 1 of the transfer component.

[0064] When the manipulator 4 clamps the wafer to reach as shown in Figure 3When the distance between the wafer 2 and the vacuum chuck 1 shown in the figure is such that the manipulator 4 does not further vertically move the wafer 2 away from the vacuum chuck 1, instead, the wafer 2 is translated horizontally towards the right in the figure, gradually bringing it to the position as shown in Figure 4 . This movement process can be parallel to the contact surface between the wafer and the vacuum chuck.

[0065] At the Figure 4 shown position, the wafer 2 only partially covers the two vacuum chucks 1. At the position where the wafer 2 and the vacuum chuck 1 overlap each other, a water film 3 still remains between them, and the water film 3 does not break. The figure shows the distance H by which the manipulator 4 moves upward away from the vacuum chuck 1. This is because when the wafer 2 is gradually transported horizontally by the jaws of the manipulator 4, as the overlapping area between the wafer 2 and the vacuum chuck 1 gradually decreases, the area of the water film 3 between them also gradually decreases.

[0066] During this process, due to the action of liquid tension, although the area of the water film 3 gradually decreases, it does not overcome the liquid tension of the water film and will not cause the water film 3 to break or rupture. However, as the area of the water film 3 decreases, the tensile force of the water film 3 between the wafer 2 and the vacuum chuck 1 gradually decreases, and the force exerted by the water film 3 on the wafer 2 also gradually becomes smaller. Therefore, at the Figure 4 shown relative position, even if the manipulator 4 continues to vertically move the wafer 2 away from the vacuum chuck 1, causing the water film 3 to break, it will not cause severe vibration and trembling at the end of the jaws of the wafer 2 and the manipulator 4, and thus can avoid damage to the contact part between the two. Compared with vertically separating the wafer 2 from the vacuum chuck 1 at the Figure 2 shown position, beneficial technical effects can be achieved.

[0067] During the process of reducing the area of the water film, it is possible to detect whether the overlapping area or the area of the water film between the wafer 2 and the vacuum chuck 1 is less than a preset value. When it is less than the preset value, the process can proceed to the step of breaking the water film; when it is greater than or equal to the preset value, it returns to the step of reducing the area of the water film, that is, continue to reduce the water film until it is detected that the overlapping area or the area of the water film is less than the preset value. This detection step can be carried out by visual inspection or a sensor.

[0068] In the present invention, the preset value is 1 / 10 or 1 / 5 of the wafer area to define the overlapping area between the wafer 2 and the vacuum chuck 1. It should be noted that the preset value can also be other values, such as 1 / 6 or 1 / 8 of the wafer area.

[0069] In another operation mode, the manipulator 4 drives the wafer 2 to swing to Figure 4After the position, the manipulator 4 can also continue to drive the wafer 2 to move horizontally until the water film 3 between the wafer 2 and the vacuum chuck 1 gradually becomes smaller and until it gradually disappears completely. This method also maximally overcomes the vibration damage of the wafer and the manipulator caused by the rupture of the water film. The subsequent horizontal movement of the wafer can also be horizontal, vertical, swinging, rotating, etc.

[0070] In this Figure 4 example, relative to Figure 2 the position shown, the manipulator 4 has caused the wafer 2 to move horizontally in the Figure 4 in the horizontal direction, achieving the effect of gradually reducing the area of the water film 3. In other embodiments, the wafer 2 can also be made to perform other horizontal movements relative to the vacuum chuck 1. For example, the wafer 2 can move horizontally in the Figure 4 in the vertical direction relative to the vacuum chuck 1, the wafer 2 can swing or rotate horizontally relative to the vacuum chuck 1, etc. Through these horizontal movements, the effect of gradually reducing the area of the water film 3 can also be achieved, and the force of the water film 3 on the wafer 2 can be reduced. For example, Figure 6 shows an example in which the manipulator 4 drives the wafer 2 to swing horizontally.

[0071] In the present invention, swinging refers to the manipulator 4 driving the wafer 2 to swing, and rotation is to make the wafer 2 rotate around its own center. Swinging and translation can reduce the overlapping area between the wafer and the vacuum chuck, while rotation can stretch the middle liquid layer and reduce the liquid layer area, playing a role in reducing the water film tension to a certain extent. It can be understood that a driving module can be configured for the clamping wheel of the jaw to drive the clamping wheel to rotate around its own axis, and the frictional force between the clamping wheel and the edge of the wafer can drive the wafer 2 to rotate. That is, a driving module can be configured for the clamping wheels of the first jaw 7, the second jaw 8, the third jaw 9, and the fourth jaw 10 to realize the rotation of the wafer 2.

[0072] Figure 6 shows a top view schematic of the polishing manipulator jaw in the wafer processing device, and at the same time shows the vacuum chuck 1 and the wafer 2 of the transfer component in the third positional relationship.

[0073] When the manipulator 4 holds the wafer 2 to reach the distance between the wafer 2 and the vacuum chuck 1 as shown in Figure 3 , the manipulator 4 does not further vertically move the wafer 2 away from the vacuum chuck 1, but horizontally swings the wafer 2 to gradually reach the position as shown in Figure 6 .

[0074] In Figure 6At the position shown, the wafer 2 only partially covers one of the vacuum chucks 1 in the figure. At the position where the wafer 2 and the vacuum chuck 1 overlap with each other, a water film 3 still remains between them, and the water film 3 does not break. This is because when the wafer 2 is gradually swung horizontally by the jaws of the manipulator 4, as the overlapping area between the wafer 2 and the vacuum chuck 1 gradually decreases, the area of the water film 3 between them also gradually decreases.

[0075] In this process, although the area of the water film 3 shown in the figure gradually decreases, the liquid tension of the water film is not overcome, and the water film 3 will not break or fracture. At this time, as the area of the water film 3 decreases, the tensile force of the water film 3 between the wafer 2 and the vacuum chuck 1 gradually decreases, and the force exerted by the water film 3 on the wafer 2 also gradually becomes smaller. Therefore, at Figure 6 the relative position shown, even if the manipulator 4 moves the wafer 2 vertically away from the vacuum chuck 1 again, causing the water film 3 to break, it will not cause severe vibration and trembling of the wafer 2 and the manipulator 4, and thus it is possible to avoid damage to the contact part between the two. Compared with Figure 2 the position shown, when the wafer 2 is vertically separated from the vacuum chuck 1, beneficial technical effects can be achieved.

[0076] In another operation mode, after the manipulator 4 drives the wafer 2 to swing to the Figure 6 position, the manipulator 4 can also continue to drive the wafer 2 to move horizontally until the water film 3 between the wafer 2 and the vacuum chuck 1 gradually becomes smaller and until it gradually completely disappears. This method also maximally overcomes the vibration and trembling damage of the wafer and the manipulator caused by the breakage of the water film.

[0077] In other embodiments, after reaching the Figure 6 position shown, the subsequent horizontal movement of the wafer can also be lateral, vertical, swinging, rotating, etc., so that the water film 3 gradually disappears.

[0078] Here, referring back to the wafer processing apparatus shown in Figure 1 and the relevant descriptions in this specification, in an alternative embodiment of the present invention, Figures 2 to 6 the manipulator 4 in Figure 1 can be the polishing manipulator 33 of the wafer processing apparatus in Figures 2 to 6 ; in other embodiments, Figure 1 the manipulator 4 in

[0079] Figure 7 can also be the manipulator in other modules of the wafer processing apparatus in

[0080] For example, but not limited to, the grinding manipulator 42 in the grinding module 21, etc. Figures 1 to 6 Combined with Figure 7As can be seen from the flowchart, the wafer picking method of the present invention is used to pick up the wafer 2 from the vacuum chuck 1, and the method includes the following steps I to III. Specifically, it includes: Step I, reducing the area of the water film 3 between the wafer 2 and the vacuum chuck 1; Step II, moving the wafer 2 away from the vacuum chuck 1 to break the water film; Step III, taking away the wafer 2.

[0081] Optionally, before the step I, a manipulator 4 can be used to transport the wafer 2 so that the wafer 2 vertically moves away from the vacuum chuck 1 by a certain distance. According to specific situations, the distance can be 200 μm to 400 μm; more specifically, in a further optional embodiment, the distance can also be 300 μm. Before horizontally transporting the wafer, by first making the wafer vertically move away from the vacuum chuck by a certain distance and then performing horizontal transportation, it is possible to avoid scratching the wafer by particles such as debris and crystal slag between the wafer and the vacuum chuck. It can be understood that in the cleaning process before wafer picking, there may be debris, crystal slag, etc. that are not washed away, which affect wafer transportation. The operation of this step avoids such adverse situations.

[0082] In step I, the area of the water film 3 between the wafer 2 and the vacuum chuck 1 is reduced.

[0083] In a specific embodiment, reducing the area of the water film 3 can be achieved by using the manipulator 4 to horizontally transport the wafer 2. Specifically, it is moved parallel to the contact surface between the wafer 2 and the vacuum chuck 1. By horizontally transporting the wafer 2 with the manipulator 4, the wafer 2 can be horizontally moved, rotated or swung relative to the vacuum chuck 1, gradually changing the positional relationship between the wafer and the vacuum chuck, reducing the overlapping area between the wafer 2 and the vacuum chuck 1, and gradually reducing the area of the water film, thereby reducing the liquid tensile force of the water film between the wafer and the chuck. After this process, after the liquid tensile force is reduced to a certain extent, breaking the water film will not cause violent vibrations of the wafer and the manipulator, and can protect the wafer and the manipulator from damage.

[0084] As described above, if after making the wafer 2 vertically move away from the vacuum chuck 1 by a certain distance, then in step I, the manipulator 4 is used to horizontally move, rotate or swing the wafer 2, it is possible to avoid scratching the wafer caused by debris, crystal slag, etc.

[0085] In addition, in some embodiments, in order to more stably reduce the water film, in the above-mentioned step I, a certain amount of gas can also be distributed to the wafer 2 via the vacuum chuck 1 to break the vacuum between the vacuum chuck 1 and the wafer 2. In this case, optionally, the vacuum chuck 1 can be made of a porous ceramic material, and the gas distribution is carried out by the porous ceramic material. A gas channel can be provided below the vacuum chuck, and its communication with the wafer surface is realized through the porous ceramic to realize the inlet and outlet of gas or other fluids and adjust the properties of the water film. When clean gas is distributed between the wafer and the vacuum chuck, the gas can accelerate the evaporation of moisture to assist in reducing the area of the water film; when clean gas is distributed to the water film, according to the distribution amount and distribution speed of the gas, the liquid tension can also be appropriately decomposed, which is beneficial to the uniform and gradual reduction of the water film area, and no violent vibration will occur.

[0086] In step II, the wafer 2 is moved away from the vacuum chuck 1 to break the water film.

[0087] In this step, a robot 4 can be used to carry the wafer 2 so that the wafer 2 moves away perpendicularly to the vacuum chuck 1 to break the tension and pull open the water film. Or, in an alternative embodiment, a robot 4 can be used to carry the wafer 2 so that the wafer 2 continues to move horizontally, rotate or swing relative to the vacuum chuck 1, gradually move away from the vacuum chuck, and finally break the tension and pull open the water film.

[0088] Since the liquid tension has been reduced by reducing the water film area and / or distributing gas through the vacuum chuck in the previous step I, breaking the water film in this step II will not cause violent vibration of the wafer and the robot, and damage caused thereby can be avoided. Optionally, during the process of breaking the water film, gas can also be distributed to the wafer 2 via the vacuum chuck 1, which can help reduce the unwanted vibration of components.

[0089] During the process of step I, the overlapping area or the water film area between the wafer 2 and the vacuum chuck 1 can also be detected to see if it is less than a preset value: when it is less than the preset value, proceed to step II of breaking the water film; when it is greater than or equal to the preset value, return to step I of reducing the water film, that is, continue to reduce the water film. This detection can be achieved by visual inspection or a sensor.

[0090] In step III, the wafer 2 is removed. After the water film between the wafer and the vacuum chuck is broken, the robot can remove the wafer 2 by an appropriate motion mode and carry it to the next process.

[0091] The present invention further provides a wafer transfer method applied to a wafer processing apparatus 20. The wafer transfer method may include the step of using a robot 4 to pick up a wafer 2 from a vacuum chuck 1, wherein the robot 4 picks up the wafer 2 from the vacuum chuck 1 by the method described in any one of the foregoing embodiments. The wafer processing apparatus 20 may include a grinding module 21, a polishing module 22, and a transfer assembly between the grinding module 21 and the polishing module 22, such as Figure 1 the second transfer unit 27 in

[0092] The transfer assembly includes a vacuum chuck 1. The robot 4 may be a polishing robot 33 at the polishing module 22, and the polishing robot 33 is used to carry the wafer 2 from the transfer assembly to the polishing module 22. In other alternative embodiments, the robot 4 may be a robot in other transfer assemblies or transfer units of the wafer processing apparatus 20.

[0093] Grinding the wafer by using the grinding module 21 of the wafer processing apparatus 20;

[0094] Transferring the ground wafer to the polishing module of the wafer processing apparatus by using the wafer transfer method;

[0095] Polishing the wafer by using the polishing module 22.

[0096] The present invention further provides a computer storage medium, on which a computer program is stored. When the program is executed by a processor, the foregoing wafer picking method can be implemented. Specifically, a system or device equipped with a storage medium may be provided. A software program code for implementing the functions of any one of the foregoing embodiments is stored on the storage medium, and the computer (or CPU or MPU) of the system or device reads and executes the program code stored in the storage medium. In this case, the program code read from the storage medium itself can implement the functions of any one of the foregoing embodiments. Therefore, the program code and the storage medium storing the program code constitute a part of the present application. Embodiments of the storage medium for providing the program code include floppy disks, hard disks, magneto-optical disks, optical disks (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), magnetic tapes, non-volatile memory cards, and ROMs. Alternatively, the program code may be downloaded from a server computer via a communication network.

[0097] The present invention further provides a wafer transfer device. The wafer transfer device may include a vacuum chuck 1 and a transfer mechanism. For example, the transfer mechanism may include the aforementioned manipulator for gripping the wafer. The vacuum chuck is configured to receive the wafer. The transfer mechanism is configured to grip the wafer from the vacuum chuck by the method described in any one of the foregoing embodiments. Optionally, the wafer transfer device may further include a controller connected to the transfer mechanism. An execution program may be built into the controller, and the controller is configured to be able to run the execution program to control the transfer mechanism to execute the wafer picking method.

[0098] The present invention further provides a wafer processing device 20. The wafer processing device 20 may include a grinding module 21, a polishing module 22, and a transfer component between the grinding module 21 and the polishing module 22. During the process of the wafer 2 being thinned and returned in the grinding module 21, a cleaning operation is performed on the back of the wafer, and a water film adheres to the surface of the wafer after cleaning. The transfer component includes the vacuum chuck 1, and the manipulator 4 is a polishing manipulator of the polishing module 22. The polishing manipulator is used to transport the wafer 2 from the transfer component to the polishing module 22. Moreover, the polishing manipulator grips the wafer 2 from the vacuum chuck 1 by the method described in any one of the foregoing embodiments to avoid damage to the wafer and / or the manipulator caused by the vibration and trembling due to the destruction of the liquid tension between the wafer and the vacuum chuck.

[0099] Specifically, the thinning process of the wafer 2 in the thinning station of the wafer processing device 20 may be as follows: The wafer 2 is transported to the grinding module 21 by the transfer component, and after being thinned in the grinding module 21, it is gripped by the manipulator 4 via the transfer component and transferred to the polishing module 22. The transfer component has a vacuum chuck 1 for adsorbing the wafer 2, and the manipulator 4 may have jaws for gripping and transporting the wafer 2. The manipulator 4 in this example may be a polishing manipulator 33.

[0100] The technical scope of the present invention is not limited to the content in the above specification. Those skilled in the art can make various deformations and modifications to the above embodiments without departing from the technical idea of the present invention, and these deformations and modifications should all fall within the scope of the present invention.

Claims

1. A wafer thinning device, characterized in that: The wafer thinning equipment comprises: A grinding module, comprising a grinding unit for grinding the wafer and a cleaning unit for cleaning the wafer; A wafer transfer device, comprising a vacuum suction cup and a manipulator, wherein the vacuum suction cup is used to absorb the wafer received from the grinding module, the surface of the wafer is covered with a water film, and the manipulator has a claw for clamping the wafer from the vacuum suction cup and carrying the wafer; The robot is configured to: move the wafer vertically away from the vacuum suction cup by a distance of 200 μm to 400 μm, and the water film is not broken within the distance; then move the wafer parallel to the contact surface between the wafer and the vacuum suction cup to reduce the area of ​​the water film between the wafer and the vacuum suction cup; and then move the wafer away from the vacuum suction cup to break the water film and remove the wafer.

2. The wafer thinning device according to claim 1, characterized in that: The vacuum suction cups include two rectangular vacuum suction cups, the wafer covers the two rectangular vacuum suction cups, and when clamping the wafer, the robot is inserted into the bottom of the wafer, passes between the two rectangular vacuum suction cups, and clamps the wafer with claws.

3. The wafer thinning device according to claim 1, characterized in that: The vacuum suction cup is made of porous ceramic material, and a gas channel is provided underneath the vacuum suction cup. The gas channel communicates with the wafer surface through the porous ceramic to distribute gas to the wafer. The gas evaporates water to assist in reducing the water film area. The wafer transfer device decomposes liquid tension and evenly and gradually reduces the water film area according to the distribution amount and distribution speed of the gas.

4. The wafer thinning device according to claim 1, characterized in that: Moving the wafer parallel to the contact surface between the wafer and the vacuum chuck includes: translating or swinging the wafer parallel to the contact surface between the wafer and the vacuum chuck.

5. The wafer thinning device according to claim 1, characterized in that: The wafer transfer device also includes a controller connected to the robot, and the controller controls the robot to perform an action of clamping the wafer.

6. The wafer thinning device according to claim 1, characterized in that: The robot comprises a first group of claws and a second group of claws, wherein the first group of claws comprises a first claw and a second claw placed in parallel, and the second group of claws comprises a third claw and a fourth claw placed in parallel, and the first group of claws and the second group of claws can move relative to each other so as to clamp and carry the wafer.

7. The wafer thinning device according to claim 1, characterized in that: The wafer thinning equipment also includes an equipment front-end module, which is arranged at the front end of the wafer thinning equipment and is used to realize the entry and exit of the wafer.

8. The wafer thinning device according to claim 1, characterized in that: The wafer thinning equipment also includes a post-processing unit for cleaning and drying the wafer, and the post-processing unit includes a horizontal brushing device.

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