Thinning wafer surface full coverage cleaning method and thinning equipment

Abstract

The present invention discloses a method and equipment for cleaning the surface of a thinned wafer with full coverage, wherein when the wafer that has completed grinding is in a loading and unloading position, the top surface of the wafer is cleaned by a top cleaning mechanism; then, a material transfer mechanism absorbs the wafer on the wafer stage and moves it to a bottom cleaning mechanism; the material transfer mechanism moves the adsorbed wafer to the bottom cleaning mechanism, and the bottom surface of the wafer adsorbed by the material transfer mechanism is cleaned by the bottom cleaning mechanism, and the cleaning component of the material transfer mechanism cleans the edge of the wafer during any period or the entire period between the movement and the bottom cleaning mechanism completing the cleaning; after the cleaning is completed at the bottom cleaning mechanism, the material transfer mechanism moves the adsorbed wafer and places it into a cleaning bucket for cleaning the top surface of the wafer, and after cleaning, the loading and unloading mechanism unloads the wafer. The present invention can ensure the cleanliness of the bottom surface and edge of the wafer before the cleaning bucket is cleaned, avoid dirt being adsorbed by a ceramic suction cup to cause blockage, and avoid affecting the cleanliness of the material box.

Description

Technical Field

[0001] The invention relates to the field of semiconductor device processing, in particular to a full-coverage cleaning method for a thinned wafer surface and a thinning device. Background Art

[0002] Thinning machine is a device used to thin semiconductor devices such as wafers.

[0003] The invention patent application with application publication number CN115338717A discloses a thinning machine, in which three wafer carriers are arranged on a dividing table. After the wafers ground by two thinning mechanisms are rotated to the loading and unloading positions along with the wafer carriers, the top surface of the wafer is cleaned by a cleaning part. After cleaning, the third manipulator transfers the wafers cleaned by the cleaning part to the cleaning part for cleaning the top surface of the wafer again.

[0004] In this solution, only the top surface of the wafer is cleaned, and the bottom surface and edge of the wafer are not cleaned. However, when the third robot absorbs the wafer from the wafer stage, after the wafer stage is unvacuumed, it is necessary to blow air back to the wafer to remove the wafer. Since water is sprayed during the grinding process, there will be water mist mixed with silicon powder in the thinning chassis. Therefore, when the air is blown back, the water mist mixed with silicon powder will be blown to the bottom surface and edge of the wafer, causing the bottom surface and edge of the wafer to be dirty.

[0005] This not only affects the cleaning quality of the wafer, but also affects subsequent processing. When the wafer is subsequently transferred to the cleaning bucket for cleaning, the silicon powder residue on the bottom of the wafer will be absorbed by the ceramic suction cup, thereby blocking the ceramic suction cup and the vacuum pipeline; and the dirt remaining on the bottom and edge of the wafer will also cause the cleanliness of the wafer box to deteriorate, affecting the subsequent reliable use. Summary of the invention

[0006] The purpose of the present invention is to solve the above problems existing in the prior art and to provide a method for fully covering the surface of a thinned wafer and a thinning device.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] A method for fully covering the surface of a thinned wafer comprises the following steps:

[0009] S1, when the wafer stage where the ground wafer is located is in the loading and unloading position, the top cleaning mechanism cleans the top surface of the wafer;

[0010] S2, after the top cleaning mechanism completes cleaning, the material transfer mechanism absorbs the wafer on the wafer stage and drives the wafer to move to the bottom cleaning mechanism;

[0011] S3, when the wafer adsorbed by the material moving mechanism moves to the bottom surface cleaning mechanism, the material moving mechanism cooperates with the bottom surface cleaning mechanism to clean the bottom surface of the wafer adsorbed by the material moving mechanism; during any time period or the entire time period from when the suction cup of the material moving mechanism adsorbs the wafer on the wafer stage to when the wafer is cleaned at the bottom surface cleaning mechanism, the material moving mechanism cleans the edge of the wafer adsorbed by it through the cleaning component thereon;

[0012] S4, after the bottom surface cleaning mechanism completes cleaning, the material transfer mechanism moves the adsorbed wafer and places it into the cleaning bucket to clean the top surface of the wafer;

[0013] S5, after the cleaning bucket completes cleaning, the wafer is taken out from the cleaning bucket through the loading and unloading mechanism and placed into the material box.

[0014] Preferably, in the method for fully covering the surface of a thinned wafer, the material moving mechanism includes a rotating arm, one end of the rotating arm is connected to a ring-shaped cleaning component that can move up and down relative to the rotating arm, a suction cup is connected below the cleaning component, and the cleaning component includes a circle of cleaning holes arranged around the suction cup with the outlet end facing downward.

[0015] Preferably, in the method for fully covering the surface of a thinned wafer, the inlet end of the cleaning hole is circular, the outlet end of the cleaning hole is an arc concentric with the suction cup, the inlet end is located in the middle position above the outlet end and the arc length of the outlet end is greater than the diameter of the inlet end.

[0016] Preferably, in the method for fully covering the surface of a thinned wafer, the pipe joint of the cleaning component is connected to an air supply system and / or a liquid supply system.

[0017] Preferably, in the method for fully covering the surface of a thinned wafer, the cleaning component forms an air barrier around the wafer during the period from when the suction cup moves to be coaxial with the wafer on the wafer stage to when the suction cup adsorbs the wafer on the wafer stage and lifts it to a target height.

[0018] Preferably, in the method for fully covering the surface of a thinned wafer, the bottom surface cleaning mechanism includes a bracket arranged in a drainage groove, the bracket is provided with a protective cover and a rotating shaft driven to rotate by a power source, the rotating shaft is connected to a cleaning brush above the protective cover, and a bottom surface cleaning nozzle that sprays water upward is provided below the cleaning brush.

[0019] Preferably, in the method for fully covering the surface of a thinned wafer, an annular water shield is provided above the protective cover, which is concentric with the rotating shaft and surrounds the outer periphery of the cleaning brush; when the material transfer mechanism adsorbs the wafer at the bottom surface cleaning mechanism for cleaning, the cleaning component covers the opening at the top of the annular water shield.

[0020] Preferably, in the method for fully covering the surface of a thinned wafer, the cleaning barrel comprises an upper cover driven to open and close by a driver, and a swing cleaning assembly is provided on the upper cover.

[0021] Preferably, in the method for fully covering the surface of a thinned wafer, an ion blower is provided on the upper cover.

[0022] Preferably, in the method for fully covering the surface of a thinned wafer, the ion blower is caused to generate ion wind during the entire process of cleaning the top surface of the wafer in the cleaning bucket or within a certain period of time.

[0023] The thinning equipment comprises a wafer stage arranged on a dividing table, a top cleaning device for cleaning the ground wafer on the wafer stage at a loading and unloading position, a cleaning barrel, and a material transfer mechanism for transferring the wafer between the wafer stage at the loading and unloading position and the cleaning barrel;

[0024] The material transfer mechanism comprises a cleaning component and a suction cup concentrically arranged below the cleaning component, wherein the cleaning component comprises a circle of cleaning holes arranged around the suction cup and with the outlet end facing downward;

[0025] The suction cup of the material transfer mechanism can be moved to the bottom surface cleaning mechanism, and the bottom surface cleaning mechanism has a structure for cleaning the bottom surface of the wafer adsorbed on the material transfer mechanism.

[0026] The advantages of the technical solution of the present invention are mainly reflected in:

[0027] After the top cleaning mechanism cleans the top surface of the wafer, the material transfer mechanism sucks the wafer and then cleans the edge of the wafer through the cleaning component thereon, thereby effectively ensuring the cleanliness of the edge. After the edge is cleaned, the bottom surface of the wafer sucked by the material transfer mechanism is cleaned by setting a bottom cleaning mechanism, thereby ensuring the cleanliness of the bottom surface of the wafer, and further ensuring that when the wafer is transferred to the cleaning bucket for cleaning, no dirt is absorbed by the ceramic suction cup to cause blockage, and at the same time, it is ensured that when the wafer is transferred to the material box, the cleanliness of the material box will not be affected.

[0028] The cleaning component of the present invention adopts a microporous structure, which can not only clean the edge of the wafer, but also form an air barrier around the wafer when backblowing and sucking the wafer, thereby reducing the risk of contamination of the edge and bottom of the wafer. It can also limit the horizontal position of the wafer, which can effectively avoid the horizontal position of the wafer from being offset during backblowing.

[0029] The bottom cleaning mechanism of the present invention is directly arranged in the original drainage groove of the thinning equipment, which can effectively simplify the structure of the bottom cleaning mechanism, and the material transfer mechanism and the circular water shield of the bottom cleaning mechanism cooperate to effectively avoid water splashing when spraying water upward. At the same time, the use of a pneumatic motor can effectively avoid electrical connection, reduce the difficulty of protection during water washing, and improve the safety and stability of equipment operation.

[0030] The present invention arranges the swing cleaning assembly on the upper cover, which can effectively reduce the size of the swing cleaning assembly and the horizontal space occupied by the swing cleaning assembly, which is conducive to making the equipment more compact. At the same time, there is no complicated waterproofing problem required when the swing cleaning assembly is arranged at the bottom of the cleaning tank. The upper cover is integrated with an ion fan, which can effectively eliminate static electricity and dust on the wafer and the adsorption plate, and improve the cleaning effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a partial stereogram of the thinning device of the present invention;

[0032] Figure 2 It is a partial stereogram of the material transfer mechanism of the present invention;

[0033] Figure 3 It is a partial exploded view of the material transfer mechanism of the present invention;

[0034] Figure 4 It is a stereoscopic diagram of the cleaning assembly and the suction cup in the material transfer mechanism of the present invention;

[0035] Figure 5 is a three-dimensional diagram of the bottom surface cleaning mechanism of the present invention;

[0036] Figure 6 is an exploded view of the bottom surface cleaning mechanism of the present invention;

[0037] Figure 7 is a partially exploded perspective view of the cleaning bucket of the present invention;

[0038] Figure 8 It is a process schematic diagram of the cleaning method of the present invention;

[0039] Fig. 9 It is a schematic diagram of the process of forming an air barrier in the cleaning method of the present invention. DETAILED DESCRIPTION

[0040] The purpose, advantages and features of the present invention will be illustrated and explained by the non-limiting description of the following preferred embodiments. These embodiments are only typical examples of the application of the technical solution of the present invention, and any technical solution formed by equivalent replacement or equivalent transformation falls within the scope of protection claimed by the present invention.

[0041] In the description of the scheme, it should be noted that the terms "center", "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience and simplification of description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0042] The following is an explanation of the thinned wafer surface full coverage cleaning method disclosed by the present invention in conjunction with the accompanying drawings. The thinned wafer surface full coverage cleaning method is based on a thinning device, such as the attached Figure 1 As shown, the structure of the thinning device can refer to the structure disclosed in the patent application cited in the background art. In addition, the thinning device of the present invention is improved as follows based on the above-mentioned prior art:

[0043] (1) The material transfer mechanism 300 for transferring the wafer from the wafer stage 100 at the loading and unloading position to the cleaning bucket 200 is improved.

[0044] (2) A bottom surface cleaning mechanism 400 is added, and the bottom surface cleaning mechanism 400 is located on the moving path of the suction cup 330 of the material transfer mechanism 300 .

[0045] (3) The structure of the cleaning barrel 200 is improved.

[0046] Specifically, as in the prior art, the material transfer mechanism 300 includes a rotating arm 310 that can rotate around a vertically extending support shaft. The difference from the prior art is that, as shown in the attached Figure 2 As shown, the far end of the rotating arm 310 (the end away from the supporting shaft) is connected to a ring-shaped cleaning assembly 320 that can move up and down relative to the rotating arm 310. A suction cup 330 is connected below the cleaning assembly 320. The diameter of the suction cup 330 is equivalent to the diameter of the wafer and smaller than the diameter of the cleaning assembly 320. The cleaning assembly 320 includes a circle of cleaning holes 326 arranged around the suction cup 330 and with the outlet end facing downward.

[0047] As attached Figure 3As shown, the cleaning assembly 320 includes an annular top cover 321 and an annular lower plate 322 which is concentrically connected to the top cover 321. A group of guide rods 340 extending in the vertical direction are arranged on the top of the top cover 321. A group of guide rods 340 are evenly distributed around the axis of the top cover 321. A group of guide rods 340 are connected to the connecting plate 350 at the far end of the rotating arm 310 so as to be movable up and down. The upper ends of the guide rods 340 are connected to the limit blocks 341 located above the connecting plate 350. At the same time, each guide rod 340 is provided with a floating spring 360, one end of which abuts against the bottom surface of the connecting plate 350, and the other end thereof abuts against the top of the top cover 321. An annular groove 323 is recessed on the top surface of the lower plate 322, and the annular groove 323 is concentric with the lower plate 322. A water inlet hole 324 connected to the annular groove 323 is provided on the top cover 321, and a pipe joint 325 is provided at the water inlet hole 324, and the pipe joint 325 is connected to the air supply system and / or the liquid supply system. Preferably, the pipe joint 325 is connected to a known parallel air supply system and liquid supply system, and the air supply system and the liquid supply system can be independently controlled to open and close. The annular groove 323 is connected to a circle of cleaning holes 326 located below it. The number of the cleaning holes 326 can be designed as needed, and the cleaning holes 326 can be circular holes. More preferably, in order to allow the ejected medium to fully cover the entire circumference of the suction cup 330, the inlet end of the cleaning hole 326 is made circular, as shown in the attached figure. Figure 4 As shown, the outlet end of the cleaning hole 326 is an arc concentric with the suction cup 330, the inlet end is located in the middle position above the outlet end and the arc length of the outlet end is greater than the diameter of the inlet end, the diameter of the inlet end is between 0.5-5 mm, the width of the outlet end is equivalent to the diameter of the inlet end, and the arc length of the outlet section is, for example, between 2-10 mm. At the same time, the length of the hole section of the cleaning hole 326 located between the inlet end and the outlet end increases from top to bottom. In this way, after ventilation or water flow, the water and air sprayed from each cleaning hole 326 can diffuse to both sides of the cleaning hole, forming a larger coverage area, so that the number of cleaning holes 326 can be reduced while achieving full coverage of the entire periphery of the suction cup 330. Reducing the number of cleaning holes 326 is conducive to ensuring the structural strength of the lower plate 322.

[0048] A further improvement to the material transfer mechanism 300 is that the suction cup is connected not only to the vacuum system but also to the air supply system. The reason for this design is that the present invention further adds a bottom surface cleaning mechanism, which uses a cleaning brush for brushing. The cleaning brush needs to be cleaned after being used for a certain period of time. Therefore, when necessary, the suction cup of the material transfer mechanism can be used to blow air to the rotating cleaning brush, thereby achieving the cleaning brush blowing to remove the residual powder on the cleaning brush.

[0049] As attached Figure 4 , Attachment Figure 5 As shown, the bottom surface cleaning mechanism 400 includes a bracket arranged in the original drainage groove 500 of the thinning device, which can effectively simplify the structure of the bottom surface cleaning mechanism 400. The bracket is provided with a protective cover 480 and a rotating shaft 450 driven to rotate by a power source 430. The bracket includes a Z-shaped base frame 410 and a U-shaped mounting groove 420 arranged on the top of the base frame 410. The bottom of the upper plate of the base frame 410 is connected to the power source 430 through a connecting plate. The power source 430 is preferably a pneumatic motor. Of course, in other embodiments, a motor may also be used. The power output shaft of the power source 430 is connected to the rotating shaft 450 through a coupling 440 located at the U-shaped mounting groove 420. The rotating shaft 450 is rotatably connected to a bearing seat 470 provided on the U-shaped mounting groove 420 through a bearing 460. The rotating shaft 450 may pass through the top plate of the protective cover 480 or the rotating shaft 450 may be torque-connected to a transmission shaft, and the transmission shaft may be rotatably provided on the top plate of the protective cover 480 relative to the protective cover. The protective cover 480 is a rectangular cover with an open bottom, and the top plate of the protective cover 480 is connected to the top plate of the U-shaped mounting groove 420. The rotating shaft 450 is passed through the top plate of the protective cover 480 and connected to a cleaning brush or the transmission shaft is connected to a cleaning brush. More preferably, in order to facilitate the connection of the cleaning brush, the upper end of the rotating shaft 450 or the upper end of the transmission shaft is concentrically connected to a connecting head 490 located above the protective cover 480, and an adjustment plate 401 is provided on the connecting head 490. The adjustment plate 401 can adjust the horizontal installation position and is connected to the top of the connecting head 490, and the cleaning brush 402 is provided on the top of the adjustment plate 401.

[0050] As attached Figure 4 , Attachment Figure 5 As shown, in order to prevent water splashing during cleaning, a circular water retaining cover 403 is provided above the protective cover 480, which is concentric with the rotating shaft 450 and surrounds the outer periphery of the cleaning brush 402. The radius of the circular water retaining cover 403 is not less than the distance from the axis of the rotating shaft 450 to the end of the cleaning brush 402 away from the rotating shaft 450. The bottom of the circular water retaining cover 403 is formed with an arc-shaped connecting plate 404 extending inwardly thereof, and the arc-shaped connecting plate 404 is located below the cleaning brush 402 and is connected to the top of the protective cover 480 through a group of Z-shaped connecting plates 405.

[0051] A group of bottom surface cleaning nozzles (not shown) spraying water upward are arranged below the cleaning brush 402. The bottom surface cleaning nozzles can be arranged on the arc-shaped connecting plate 404 or on the top plate of the protective cover 480, and their specific number and position can be determined as needed and are not limited here.

[0052] Furthermore, the diameter of the lower plate 322 of the cleaning component 320 is not less than the diameter of the circular water shield. When the material transfer mechanism 300 adsorbs the wafer for cleaning at the bottom surface cleaning mechanism 400, the cleaning component 320 covers the opening at the top of the circular water shield.

[0053] As attached Figure 7 As shown, like the prior art, the cleaning bucket 200 includes a cleaning tank 210, a suction plate 220 disposed at the cleaning tank 210 and a rotating component 230 driving the rotation thereof, a swing cleaning component 240, a lifting drive 250 driving the cleaning tank 210 to rise and fall, and a guide mechanism 260.

[0054] The difference from the existing cleaning bucket 200 is that the cleaning bucket 200 includes an upper cover 270 connected to the top of the cleaning tank 210 and driven by a driver to flip open and close. The specific structure of the driver driving the upper cover to rotate and open relative to the cleaning tank is a known technology. For example, the front side or the rear side of the upper cover 270 is hinged to one side of the top of the cleaning tank, the left side and / or the right side of the upper cover 270 is hinged to one end of the driver, and the other end of the driver is hinged to the outside of the cleaning tank. The driver is, for example, a cylinder, a hydraulic cylinder, an electric cylinder or other device. Taking the cylinder as an example, when the cylinder shaft of the cylinder is extended, the upper cover 270 is opened, and the wafer can be placed in the cleaning tank; when the cylinder shaft of the cylinder is retracted, the upper cover 270 is closed.

[0055] As attached Figure 7 As shown, the swing cleaning assembly 240 is arranged on the upper cover 270, and the driving component of the swing cleaning assembly 240 is a rotating cylinder 241, which can certainly be a motor, which is arranged on the top of the upper cover 270. The turntable of the driving component is passed through the inner side of the upper cover 270 and connected to the swing arm. The swing arm is provided with a liquid spray head and an air jet head for cleaning. The rotating cylinder drives the swing arm to swing back and forth above the adsorption plate 220, thereby cooperating with the rotating wafer to achieve cleaning.

[0056] Furthermore, an ion blower 280 is also disposed on the upper cover 270 , and the ion blower 280 blows ion wind toward the inner side of the upper cover 270 .

[0057] The process of wafer grinding by the thinning device is the same as that of the prior art, and will not be described in detail here. Figure 8As shown, the cleaning process after grinding is completed, that is, the thinned wafer surface full coverage cleaning method includes the following steps:

[0058] S1, when the wafer table 100 where the ground wafer is located is in the loading and unloading position, the top cleaning mechanism 600 cleans the top surface of the wafer. The specific structure of the top cleaning mechanism 600 is a known technology. It uses a brush to reciprocately scrub the top surface of the rotating wafer to clean most of the dirt on the top surface of the wafer.

[0059] S2, after the top cleaning mechanism 600 completes cleaning, the material transfer mechanism 300 absorbs the wafer on the wafer stage 100 and drives the wafer to move to the bottom cleaning mechanism 400.

[0060] Specifically, the rotating arm 310 of the material transfer mechanism 300 swings horizontally so that the suction cup 330 thereon remains coaxial with the wafer on the wafer stage 100 at the loading and unloading position, and then the suction cup 330 moves down to be close to the wafer on the wafer stage 100, and then the wafer stage 100 releases the vacuum and back-blows air, that is, the wafer stage 100 blows air toward the bottom surface of the wafer, and at the same time or shortly after the back-blow, the suction cup 330 generates suction to adsorb the wafer, and after adsorbing the wafer, the suction cup is lifted and reset to the target height, and the rotating arm 310 swings to move the wafer adsorbed by the suction cup toward the bottom surface cleaning mechanism 400.

[0061] S3, when the wafer adsorbed by the material moving mechanism 300 moves to the bottom surface cleaning mechanism 400, the material moving mechanism 300 cooperates with the bottom surface cleaning mechanism 400 to clean the bottom surface of the wafer adsorbed by the material moving mechanism 300.

[0062] Specifically, when the wafer adsorbed by the material moving mechanism 300 is coaxial with the rotating shaft 450 of the bottom cleaning mechanism 400, the material moving mechanism 300 moves the wafer downward to contact the cleaning brush 402. At this time, the cleaning component 320 covers the top of the annular water shield 403, and the bottom cleaning nozzle sprays water to the bottom surface of the wafer. The power source 430 of the bottom cleaning mechanism 400 drives the cleaning brush 402 to rotate around the rotating shaft 450 to achieve cleaning of the bottom surface of the wafer.

[0063] During any time period or the entire time period from when the material transfer mechanism 300 sucks the wafer on the wafer stage to when the wafer is cleaned at the bottom cleaning mechanism 400, the material transfer mechanism 300 cleans the edge of the sucked wafer through the cleaning component 320 thereon, and during cleaning, it is preferred to use water spraying to clean the edge.

[0064] S4, after the bottom surface cleaning mechanism 400 completes cleaning, the material transfer mechanism 300 moves the adsorbed wafer and places it into the cleaning bucket 200 to clean the top surface of the wafer;

[0065] Under normal conditions, that is, when the upper cover 270 of the cleaning barrel 200 remains closed and there is no wafer in it, the static electricity in the cleaning barrel 200 is eliminated by the ion wind generated by the ion blower 280. When the wafer starts to move toward the cleaning barrel 200 after being cleaned by the bottom cleaning mechanism 400, the upper cover 270 of the cleaning barrel 200 is opened, and when the material transfer mechanism 300 places the wafer on the adsorption plate 220 in the cleaning barrel 200, the material transfer mechanism moves out of the cleaning barrel 200, and then the upper cover 270 is closed, and the swing cleaning assembly 240 performs water washing, air blowing and other cleaning operations on the top surface of the wafer according to the set program, and the ion blower generates ion wind during the entire process of cleaning the top surface of the wafer in the cleaning barrel or within a certain period of time.

[0066] S5, after the cleaning bucket 200 completes cleaning, the wafer is taken out from the cleaning bucket 200 through the loading and unloading mechanism and placed into the material box.

[0067] As attached Fig. 9 As shown, in order to minimize the dirt on the edge and bottom of the wafer from the water mist when the material transfer mechanism 300 adsorbs the ground wafer on the wafer stage at the loading and unloading position, the cleaning component 320 forms a circle of air barrier around the wafer during the period from when the suction cup 330 moves to be coaxial with the wafer on the wafer stage 100 to when the suction cup 330 adsorbs the wafer on the wafer stage 100 and when the suction cup 330 moves to the target height. Therefore, during the back-blowing, the wafer, the wafer stage 100 and the air barrier between them can form a relatively closed space, thereby effectively reducing the intrusion of the peripheral water mist into the bottom of the wafer. At the same time, the air barrier can limit the horizontal position of the wafer to a certain extent, avoiding the horizontal position of the wafer from being offset during the back-blowing, thereby affecting the subsequent operation accuracy. The reason why the cleaning component 320 forms a circle of air barrier is that it can effectively prevent the suction hole of the wafer stage 100 from entering with water and affecting the stability of vacuum adsorption, and at the same time avoid liquid splashing. Furthermore, after the suction cup 330 absorbs the wafer, the wafer stage stops backblowing.

[0068] When the cleaning component cleans the edge of the wafer, preferably when the wafer moves to the outside of the wafer stage 100, and more preferably when the wafer is moved to the bottom cleaning mechanism 400 and the wafer is located in the annular water shield 403, the cleaning component 320 sprays water through the cleaning hole 326 to rinse the edge of the wafer, and, when the bottom cleaning mechanism 400 is cleaning, the cleaning hole 326 can clean the edge of the wafer at the same time.

[0069] There are many implementation methods of the present invention, and all technical solutions formed by equivalent transformation or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A method for cleaning the surface of a thinned wafer with full coverage, characterized in that: The steps include: S1, when the wafer stage where the ground wafer is located is in the loading and unloading position, the top cleaning mechanism cleans the top surface of the wafer; S2, after the top cleaning mechanism completes cleaning, the material transfer mechanism absorbs the wafer on the wafer stage and drives the wafer to move to the bottom cleaning mechanism; S3, when the wafer adsorbed by the material moving mechanism moves to the bottom surface cleaning mechanism, the material moving mechanism cooperates with the bottom surface cleaning mechanism to clean the bottom surface of the wafer adsorbed by the material moving mechanism; during any time period or the entire time period from when the suction cup of the material moving mechanism adsorbs the wafer on the wafer stage to when the wafer is cleaned at the bottom surface cleaning mechanism, the material moving mechanism cleans the edge of the wafer adsorbed by it through the cleaning component thereon; S4, after the bottom surface cleaning mechanism completes cleaning, the material transfer mechanism moves the adsorbed wafer and places it into the cleaning bucket to clean the top surface of the wafer; S5, after the cleaning bucket completes cleaning, the wafer is taken out from the cleaning bucket by the loading and unloading mechanism and placed into a material box; The material transfer mechanism includes a rotating arm, one end of which is connected to a ring-shaped cleaning component that can move up and down relative to the rotating arm, a suction cup is connected below the cleaning component, and the cleaning component includes a circle of cleaning holes arranged around the suction cup with the outlet end facing downward; during the period from the suction cup moving to be coaxial with the wafer on the wafer stage to the suction cup adsorbing the wafer on the wafer stage and lifting it to the target height, the cleaning component forms a circle of air barrier around the wafer.

2. The method for fully covering the surface of a thinned wafer according to claim 1, characterized in that: The inlet end of the cleaning hole is circular, the outlet end of the cleaning hole is an arc concentric with the suction cup, the inlet end is located in the middle position above the outlet end, and the arc length of the outlet end is greater than the diameter of the inlet end.

3. The method for fully covering the surface of a thinned wafer according to claim 1, characterized in that: The pipe joint of the cleaning component is connected to the air supply system and / or the liquid supply system.

4. The method for fully covering the surface of a thinned wafer according to claim 1, characterized in that: The bottom cleaning mechanism includes a bracket arranged in the drainage groove, the bracket is provided with a protective cover and a rotating shaft driven by a power source to rotate, the rotating shaft is connected to a cleaning brush above the protective cover, and a bottom cleaning nozzle that sprays water upward is arranged below the cleaning brush.

5. The method for fully covering the surface of a thinned wafer according to claim 4, characterized in that: A circular water shield is also provided above the protective cover, which is concentric with the rotating shaft and surrounds the outer periphery of the cleaning brush. When the material transfer mechanism adsorbs the wafer at the bottom surface cleaning mechanism for cleaning, the cleaning component covers the opening at the top of the circular water shield.

6. The method for fully covering the surface of a thinned wafer according to any one of claims 1 to 5, characterized in that: The cleaning barrel comprises an upper cover which is opened and closed by a driver, and a swing cleaning component and / or an ion blower are arranged on the upper cover.

7. The method for fully covering the surface of a thinned wafer according to claim 6, characterized in that: During the whole process of cleaning the top surface of the wafer in the cleaning bucket or within a certain period of time, the ion blower is made to generate ion wind.

8. Thinning equipment, comprising a wafer stage arranged on a dividing table, a top cleaning device for cleaning the ground wafer on the wafer stage at a loading and unloading position, a cleaning barrel, and a material transfer mechanism for transferring the wafer between the wafer stage at the loading and unloading position and the cleaning barrel, characterized in that: The material transfer mechanism comprises a cleaning component and a suction cup concentrically arranged below the cleaning component, wherein the cleaning component comprises a circle of cleaning holes arranged around the suction cup and with the outlet end facing downward; The suction cup of the material transfer mechanism can be moved to the bottom surface cleaning mechanism, and the bottom surface cleaning mechanism has a structure for cleaning the bottom surface of the wafer adsorbed on the material transfer mechanism; During the period from when the suction cup moves to be coaxial with the wafer on the wafer stage to when the suction cup absorbs and lifts the wafer on the wafer stage to a target height, the cleaning component forms a circle of air barrier around the wafer.

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