TW201829126A - Polishing device to prevent slurry used in polishing from being stuck on a wafer - Google Patents

Abstract

The subject of this invention is to prevent slurry used in polishing from being stuck on a wafer. The carrying-out apparatus is provided with a carrying-out pad which is plate shaped and discharges water radially from the center of the holding surface holding the wafer to form a water layer between the holding surface and the upper surface of the wafer and then to hold the wafer. The storage apparatus is configured to include a water tank; a cassette submersion apparatus to submerge the cassette in water in the water tank; tracks submerged in the water in the water tank and extended toward the cassette submerged in the water; and an underwater moving apparatus for making the wafer submerged in water on the tracks by using carrying-out apparatus and perform underwater movement toward the cassette already submerged in the water in the direction of extension of the tracks.

Description

Grinding device

FIELD OF THE INVENTION The present invention relates to a grinding apparatus.

BACKGROUND OF THE INVENTION The manufacturing steps of a semiconductor device include a polishing step of bringing a polishing pad into contact with a wafer held by a holding table and polishing the wafer. A known method is, for example, in a polishing apparatus that polishes the surface of a wafer, a polishing slurry containing free abrasive grains is supplied to the polishing surface to perform polishing. In the polishing step performed by such a polishing apparatus, when the polished wafer is dried, the polishing slurry may adhere to the surface of the wafer. For example, the following method has been proposed: in order to prevent drying of the polished wafer, a water layer is interposed between the holding surface of the transfer pad and the held surface of the wafer, and the wafer is transferred in a humid environment. Circle (for example, refer to Patent Document 1). Prior Art Literature Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2009-252877

SUMMARY OF THE INVENTION Problems to be Solved by the Invention However, even in the case where the above-mentioned wafer transfer method is used, the polishing slurry used in the polishing step may occur during the process of transferring the wafer to the contained cassette. The state that the material is fixed on the surface of the wafer.

The present invention has been made in view of the problems described above, and an object of the present invention is to provide a polishing apparatus capable of preventing a polishing slurry used in a polishing process from being fixed on a wafer. Means to solve the problem

According to one aspect of the present invention, a polishing apparatus includes a first cassette for storing wafers in a shelf shape, a holding table for holding wafers, a loading device for transferring wafers from the first cassette to the holding table, and Polishing equipment for polishing a wafer held by a polishing pad, a carrying device for removing a polished wafer from the holding table, a second cassette for storing a polished wafer in a layered shape, and a device for carrying out The polished wafer carried out from the holding table is stored in a storage device for the second cassette. The carrying out device includes a carrying-out pad which is plate-shaped and discharges water radially from the center of the holding surface holding the wafer. In addition, a water layer is formed between the holding surface and the upper surface of the wafer to hold the wafer. The storage device is provided with a water tank, a cassette submerging device for submerging the second cassette in the water in the water tank, and the first The track with two cassettes extended and submerged in the water in the water tank, and the wafer is submerged in the water with the removal equipment on the track, and the wafer is moved in the direction of the track toward the second cassette that has been submerged in water. Moving in water device.

According to this configuration, on the one hand, water can be discharged radially from the center of the holding surface of the wafer carrying pad, and a water layer is formed between the holding surface and the upper surface of the wafer to carry the wafer out of the holding table. On the other hand, in a state where the second cassette is submerged in water in the water tank, the polished wafer can be moved toward the second cassette in water. Thereby, the wafer after polishing can be carried out from the holding table in a wet state and can be transferred to the second cassette in a wet state, so that the polishing slurry used in the polishing process can be prevented from being fixed on the wafer. Superficial situation. Invention effect

According to the present invention, it is possible to prevent the polishing slurry used in the polishing process from being fixed on the wafer.

Embodiments for Carrying Out the Invention Hereinafter, a polishing apparatus according to this embodiment will be described with reference to the attached drawings. FIG. 1 is a perspective view of a polishing apparatus according to this embodiment. In addition, in FIG. 1, for convenience of explanation, a portion corresponding to the underwater mobile device 43 described later is broken and displayed. In the following, the lower left side shown in FIG. 1 is referred to as a “front side”, and the upper right side shown in the same figure is referred to as a “rear side”.

As shown in FIG. 1, the polishing apparatus 1 is configured to automatically perform a series of operations including carrying in processing, polishing processing, and carrying out processing of a wafer W, which is a workpiece. The wafer W processed in the polishing apparatus 1 is stored in a layered state in the second cassette, that is, the cassette C2, and is carried out to another apparatus, that is, a cleaning apparatus, and the front surface (upper surface) and Wash the back (lower surface).

The wafer W is formed into a substantially circular shape, and is carried into the polishing apparatus 1 in a state where the wafer C is stored in a layered rack shape as the first cassette C1. A protective tape T having the same diameter as that of the wafer W is attached to the lower surface of the wafer W (see FIG. 4). In addition, the wafer W may be a plate-like member to be polished, and may be a semiconductor wafer such as silicon or gallium arsenide, or lithium tantalate (LiTaO ₃ ; LT) or lithium niobate (LiNbO ₃₎ ; Piezoelectric materials such as LN) can also be optical element wafers such as ceramics, glass, sapphire, or as-sliced wafers before element patterns are formed.

A pair of cassettes C1 and C2 that can store a plurality of wafers W are arranged on the front side of the base 10 of the polishing apparatus 1. The wafer W before polishing processing can be stored in the cassette C1, and the wafer W after polishing processing can be stored in the cassette C2. A cassette robot 11 capable of taking out a wafer W from the cassette C1 is provided behind the cassette C1. A positioning mechanism 14 for positioning the wafer W before processing is provided behind the cassette robot 11.

On the other hand, storage devices 17 are provided on the rear and lower sides of the cassette C2 to store the processed wafers W with respect to the cassette C2. A loading device 20 is provided between the positioning mechanism 14 and the storage device 17 to load the wafer W before processing into the holding table 5. Further, a carry-out device 6 for carrying out the processed wafer W from the holding table 5 to the carry-out device 17 is provided on the rear side of the carrying device 17.

The cassette robot 11 is configured by providing a hand portion 13 at a tip end of a robot arm 12 formed by a plurality of links. The cassette robot 11 transfers the wafer W before processing from the cassette C1 to the positioning mechanism 14.

The positioning mechanism 14 is configured by arranging a plurality of positioning pins 16 around the temporary table 15 so as to be able to advance and retreat with respect to the center of the temporary table 15. The positioning mechanism 14 positions the center of the wafer W to the center of the temporary stage 15 by abutting the plurality of positioning pins 16 against the outer periphery of the wafer W already placed on the temporary stage 15.

In the carrying-in equipment 20, the wafer W is lifted from the temporary table 15 by the carrying-in pad 21, and the wafer W is carried into the holding table 5 by rotating the carrying-in pad 21 with the arm 22.

In the unloading device 6, the wafer W is lifted from the holding table 5 by the unloading pad 60 and the lifting device 61, and the arm 63 connected to the unloading pad 60 and the like is wound by the unwinding device 62 The wafer W is carried out from the holding table 5. The unloaded wafer W is transferred to the storage facility 17. The configuration of the unloading device 6 will be described later.

The storage device 17 is composed of a water tank 40 disposed on the front side of the carrying-out device 6, a cassette submerging device 41 for immersing the cassette C2 in the water in this water tank 40, and a rail extending in the water tank 40 in the front-back direction 42 and an underwater moving device 43 that transports the wafer W disposed on the rail 42 to the front side.

The water tank 40 is provided integrally with the base 10 on the front side of the carrying-out equipment 6. The water tank 40 is arranged below the cassette C2. The water tank 40 has a shape in which an opening is formed on the upper side, and contains a certain amount of water. In addition, the water tank 40 may be provided detachably from the base 10. In addition, it is possible to prevent the concentration of the polishing slurry contained in the water in the water tank 40 from being increased by continuously supplying water to the water tank 40 and overflowing the water from the water tank 40. The water in the water tank 40 can also be replaced periodically to prevent the concentration of the polishing slurry from increasing. For example, replace water with one cassette (25 tablets).

The cassette submerging device 41 includes a cassette table 411 on which the cassette C2 can be placed, and a cassette table lifting device 412 that supports the cassette table 411. The cassette stage 411 is arranged at a position corresponding to the opening of the water tank 40. The cassette stage lifting device 412 is configured to raise and lower the cassette stage 411 in a state where the cassette C2 is already mounted. Regarding details, as described later, the cassette stage lifting device 412 lowers the cassette C2 into the water tank 40 during storage of the wafer W by the underwater moving device 43 and is submerged in the water.

The rail 42 includes a pair of rail members 421 arranged at regular intervals. These rail members 421 are arranged in a position to be submerged in the water contained in the water tank 40. A plurality of wafer transfer surfaces 422 are formed on the upper surfaces of these rail members 421. These wafer transfer surfaces 422 are configured so that a stepped portion is formed in the rail member 421. These wafer transfer surfaces 422 are configured to be capable of transferring a plurality of wafers W having different sizes. For example, the wafer transfer surface 422 is configured to transfer a larger-sized wafer W (for example, 12 inches) in the upper stage, and to transfer a smaller-sized wafer (for example, 6 inches) in the lower stage, and in the middle stage Wafers W (for example, 8 inches) with a medium size can be transferred.

The underwater moving device 43 includes a guide rail 431 extending in the front-rear direction, and a slider 432 that can move back and forth along the guide rail 431. The slider 432 is provided with a support arm 433 protruding toward the inside of the device, and a telescopic member 434 configured to extend and contract from the vicinity of the front end portion of the support arm 433 to the lower side. The telescopic member 434 is arranged at the center of the pair of rail members 421 in a plan view, and is configured to be able to contact the rear end faces of the wafers W arranged on the rail members 421. The telescopic member 434 can move the wafer W toward the front side by moving the slider 432 to the front side while being in contact with the rear end surface of the wafer W.

A rectangular opening extending in the X-axis direction is formed on the upper surface of the base 10 located on the rear side of the polishing apparatus 1. This opening is covered with a moving plate 23 that can move with the holding table 5 and a bellows-shaped waterproof cover 24. A ball screw type advancement and retreat device (not shown) for moving the holding table 5 in the X-axis direction is provided below the waterproof cover 24. Further, the holding table 5 is connected to a table rotation device (not shown), and is rotatably configured to be driven around the center of the wafer W by driving of the table rotation device. A holding surface 50 a for holding a lower surface of the wafer W is formed on the upper surface of the holding stage 5.

A support 25 is provided on a pillar 25 erected from the rear of the base table 10 so as to feed the polishing device 30 toward and away from the holding table 5 (Z-axis direction). The polishing feed device 26 includes a pair of guide rails 27 arranged on the pillar 25 in parallel with the Z-axis direction, and a motor-driven Z-axis table 28 provided to be slidable on the pair of guide rails 27. A nut portion (not shown) is formed on the back side of the Z-axis table 28, and a ball screw 29 is screwed into these nut portions. When the ball screw 29 is rotationally driven by a drive motor M connected to one end of the ball screw 29, the polishing apparatus 30 can be moved in the Z-axis direction along the guide rail 27.

The polishing apparatus 30 is mounted on the front surface of the Z-axis table 28 through the casing 31, and is configured to rotate the polishing wheel 33 around the central axis by the spindle unit 32. The main shaft unit 32 is a so-called air bearing main shaft, and the main shaft 34 is rotatably supported by high-pressure air passing through the inside of the casing.

A mounting seat 35 is connected to the front end of the main shaft 34. The mount 35 is provided with a polishing wheel 33 having a polishing pad 36 on a lower surface thereof. The polishing pad 36 is formed of a foam material, a fibrous material, or the like, and is mounted on the mounting base 35 so that the center of the polishing pad 36 coincides with the center of the rotation axis. The polishing apparatus 30 uses a polishing pad 36 to polish the wafer W attracted and held by the holding table 5.

In this polishing apparatus 1, the wafer W is transferred from the cassette C1 to the positioning mechanism 14, and the wafer W is centered on the positioning mechanism 14. Next, the wafer W is carried into the holding table 5, and the holding table 5 is positioned at a processing position below the polishing apparatus 30. Then, the upper surface of the wafer W is polished by the polishing apparatus 30 in a state where a polishing slurry including free abrasive particles is supplied from a polishing slurry supply apparatus (not shown).

After the grinding process, the holding table 5 is positioned near the unloading device 6. Then, the wafer W is unloaded from the holding table 5 by the unloading device 6. The wafer W is transferred to a rail 42 provided in the storage facility 17. Thereafter, the wafer W is transferred to the cassette C2 along the rail 42 in the water tank 40 by the underwater moving device 43. When the wafer W corresponding to a predetermined number of wafers is stored in the cassette C2, the cassette C2 can be carried out to a cleaning device to clean the wafer W inside.

However, when the wafer W after the polishing process is transferred to the cassette C2, if the wafer W is dried, the polishing slurry used in the polishing step may be fixed on the surface of the wafer W. The inventor of the present invention focuses not only on the transport step after polishing, but also in the transport step before storing the polished wafer W in the cassette C2, which may be left in the wafer W due to drying. The point where the polishing slurry on the surface of the wafer W is fixed. In addition, it was found that the method of carrying out the transfer in a wet state even in such a transfer step contributes to the prevention of the fixation of the polishing material of the wafer W, and the present invention was conceived.

That is, the gist of the present invention is to discharge water radially from the center of the holding surface of the carry-out pad 60 holding the wafer W, and to form a water layer between the holding surface and the upper surface of the wafer W to remove the water. The wafer W is carried out from the holding table 5, and the wafer C is polished and moved toward the cassette C2 in the water in a state where the cassette C2 is submerged in the water tank 40. According to the present invention, since the wafer W after the polishing process can be carried out from the holding table 5 in a wet state and can be transferred to the cassette C2 in a wet state, it is possible to prevent the polishing slurry used in the polishing process from being fixed to the crystal Surface of circle W.

Hereinafter, the configuration of the carrying-out equipment 6 (the carrying-out pad 60) included in the polishing apparatus 1 according to the present embodiment will be described with reference to FIGS. 1 to 3. FIG. 2 is a perspective view showing the external appearance of a carry-out pad 60 included in the polishing apparatus 1 according to this embodiment. FIG. 3 is a perspective view for explaining a holding surface 64 of a carry-out pad 60 included in the polishing apparatus 1 according to the present embodiment. In addition, in FIG. 2, for convenience of explanation, a part of the unloading device 6 (elevating device 61) is simplified and displayed.

As shown in FIG. 1, the unloading device 6 includes a winding device 62 provided on the upper end of a pillar standing upright on the base 10, a support arm 63 extending horizontally from the peripheral surface of the winding device 62, and a front end connected to the support arm 63 A lifting device 61 and a carry-out pad 60 supported at a lower end portion of the lifting device 61.

The winding device 62 is configured between a position where the processed wafer W is received from the holding table 5 and a position where the wafer W carried out from the holding table 5 is transferred to a position on the rail 42 of the storage device 17, Rotate the carrying pad 60 out.

The arm 63 is provided to extend from the peripheral surface of the winding device 62 toward the inside of the device. The arm 63 has a length such that the front end portion thereof can be disposed above the holding surface 50 a of the holding table 5 at the transfer position of the wafer W after the polishing process, and the rear end side of the rail 42 of the storage device 17 Area above.

The lifting device 61 is configured to be capable of lifting and lowering the carry-out pad 60 in a direction approaching and moving away from the holding table 5. More specifically, the lifting device 61 is configured between a height position where the wafer W can be held on the holding table 5 and a height position where the wafer W is transported to the storage device 17 only by being distant from the holding table 5 by a certain distance. , Will lift out the pad 60.

As shown in FIG. 2, the lifting device 61 is connected to a central portion of an upper surface of a carry-out pad 60 having a disc shape. A water supply source connection portion 631 and an air supply source connection portion 632 are provided on the upper surface of the arm 63 connected to the portion of the elevating device 61. These water supply source connection portion 631 and air supply source connection portion 632 are respectively connected to a water supply source and an air supply source (not shown) to receive sprayed water from a holding surface 64 (see FIG. 3) of the carry-out pad 60 or Supply of air. A water supply pipe 633 and an air supply pipe 634 (see FIG. 4) that communicate with the water supply source connection portion 631 and the air supply source connection portion 632 are disposed inside the elevating device 61.

As shown in FIG. 3, a holding surface 64 having a plate shape and holding the wafer W is provided on the lower surface of the carry-out pad 60. A guide ring 65 is provided on an outer peripheral portion of the carry-out pad 60. This guide ring 65 is attached to the carry-out pad 60 so that the lower end portion thereof protrudes to a lower side than the body of the carry-out pad 60 (see FIG. 4). That is, the guide ring 65 is disposed so as to protrude more than the holding surface 64 of the carry-out pad 60. The inner peripheral surface of the guide ring 65 protruding more than the holding surface 64 is a ring-shaped side wall portion that surrounds the outer peripheral edge of the holding surface 64.

As shown in FIG. 3, a bottom surface portion 641 disposed on the same plane as the holding surface 64 is provided at the center of the holding surface 64. The bottom surface portion 641 has a substantially circular shape in a plan view and constitutes a part of the holding surface 64. A water supply pipe 633 (see FIG. 4) formed in the lifting device 61 is disposed above the bottom surface portion 641. The bottom surface portion 641 is arranged to extend on a plane orthogonal to the traveling direction of the water passing through the water supply pipe 633.

A plurality of (three in the present embodiment) a plurality of (three in the present embodiment) drain holes 642 that are opened toward the outer peripheral side in the radial direction of the holding surface 64 are formed above the bottom surface portion 641. These drainage openings 642 are arranged at intervals from an angle such as the center of the holding surface 64 (in this embodiment, the angle between the central portions of adjacent water outlets 642 is 120 degrees).

A plurality of (three in the present embodiment) drain grooves 643 are formed on the outer peripheral side of each drain port 642 and extend radially from the drain port 642 toward the outer peripheral side of the holding surface 64. The drainage groove 643 is formed to be more recessed than the holding surface 64. That is, the drainage groove 643 is formed in a recessed shape from a part of the holding surface 64 toward the upper side. The drain groove 643 connects one end on the center portion side of the holding surface 64 to the drain port 642 and extends the other end on the outer peripheral portion side to the vicinity of the outer peripheral edge of the holding surface 64. In addition, the other end of the drainage groove 643 does not reach the outer peripheral edge of the holding surface 64.

Moreover, the drainage groove 643 has the one end of the drainage opening 642 side (the center portion side of the holding surface 64) being the most recessed, and gradually approaches the surface side of the holding surface 64 as it goes toward the other end of the outer peripheral portion side (see FIG. 4). That is, the drainage groove 643 has the largest depth dimension at one end on the side of the drainage opening 642, and gradually becomes shallower toward the other end on the outer peripheral portion side. That is, the upper surface 643a of the drainage groove 643 is an inclined surface which gradually descends from the center portion of the holding surface 64 toward the outer peripheral side. The drainage openings 642 are arranged in a state of being opened at one end side of these drainage grooves 643 toward the outer peripheral side.

It should be noted that a portion where the drainage groove 643 is not formed in the holding surface 64 is a flat surface. As described above, the end portion on the outer peripheral side of the drainage groove 643 does not reach the outer peripheral edge of the holding surface 64. Therefore, a flat surface is disposed near the outer peripheral edge of the holding surface 64, and the flat surface is disposed on the same plane as the holding surface 64 except for the drainage groove 643.

FIG. 4 is a schematic cross-sectional view for explaining the internal structure of the carry-out pad 60 according to this embodiment. In FIG. 4, for convenience of explanation, the holding table 5 and the wafer W and the protective tape T placed thereon are shown. The protective tape T is an adhesive tape that is attached according to the type of the wafer W to be polished, and may be attached even if it is not attached. The protective tape T should preferably have a size slightly larger than the diameter of the wafer W. When the protective tape T is affixed to the wafer W, the telescopic member 434 is pressed when the wafer W is stored in the cassette C2 in the wafer water moving step (see FIG. 7) described later. Since the tape T is protected to be stored in the cassette C2, there is no need to worry about damaging the edge of the wafer W.

As shown in FIG. 4, a water supply pipe 633 communicating with the water supply source connection portion 631 is disposed inside the carry-out pad 60 and the lifting device 61. At the same time, an air supply pipe 634 communicating with the air supply source connection portion 632 is disposed inside the carry-out pad 60 and the lifting device 61. The air supply pipe 634 can be appropriately divided in the carrying-out pad 60 and can discharge air on the lower surface of the holding surface 64.

In the unloading device 6, when the processed wafer W is unloaded from the holding table 5, the valve connected to the water supply source connection portion 631 is opened and water is discharged from the drain port 642. The water discharged from the drainage port 642 is drained radially through the drainage channel 643. By carrying out drainage in a state where the holding surface 64 of the carry-out pad 60 is close to the held surface W1 of the wafer W on the holding table 5 as described above, a water layer can be formed between the held surface W1 and the holding surface 64. The water layer thus generated will generate an adsorption force on the wafer W on the holding table 5. The wafer W can be held on the holding surface 64 of the carry-out pad 60 by releasing the suction holding force of the holding table 5 in a state where the suction force is generated in this manner.

On the other hand, the unloading device 6 is configured to be connected to the air supply source connecting portion 632 when the wafer W held on the holding surface 64 of the unloading pad 60 is transferred to the rail 42 of the storage device 17. The valve is opened to discharge air from an air discharge port (not shown) of the holding surface 64. Thereby, the wafer W can be released from the water layer adsorption force acting between the holding surface 64 of the carry-out pad 60 and the held surface W1 of the wafer W to be transferred to the rail 42. The wafer W thus polished is transferred from the holding table 5 to the storage device 17 while maintaining the wet state by the water supplied from the carry-out pad 60. Therefore, it is possible to prevent the wafer W from being dried when it is transferred from the holding table 5 to the storage device 17.

Next, the configuration of the storage device 17 (water moving device 43) included in the polishing apparatus 1 according to this embodiment will be described with reference to FIG. 5. FIG. 5 is an explanatory diagram of a configuration of a storage device 17 included in the polishing apparatus 1 according to this embodiment. Moreover, in FIG. 5, for convenience of explanation, the holding table 5, the carrying-out device 6, and the cassette C2 are shown. In addition, in FIG. 5, for the convenience of description, a part of the rail 42 and the underwater moving device 43 is simplified, and the components of the cassette submerging device 41 (the cassette table 411 and the cassette lifting device 412) The position is distorted to display. In FIG. 5, the protective tape T attached to the wafer W is omitted.

As shown in FIG. 5, the unloading device 6 is arranged at a position where the wafer W on the holding table 5 can be unloaded by the transfer pad 60. The storage device 17 is disposed on the front side of the unloading device 6. The sink 40 of the storage device 17 is provided with a deep bottom portion 401 on the front side portion and a shallow bottom portion 402 on the rear side portion which is shallower than the deep bottom portion 401 on the other hand. The water tank 40 is configured by connecting these deep bottom portions 401 and shallow bottom portions 402. Water WA is contained in the water tank 40 so that the shallow bottom portion 402 may have a constant depth.

The underwater moving device 43 is located on the front side of the carrying-out device 6 and is disposed on the shallow bottom portion 402 of the water tank 40. The guide rail 431 is arranged to extend in the front-rear direction. The slider 432 is configured to be movable back and forth in the front-rear direction along the guide rail 431. The arm 433 extends from the slider 432 in a direction orthogonal to the extending direction of the guide rail 431 (on the front side of the paper surface). The telescopic member 434 is provided so that it may extend from the lower surface near the front-end | tip part of the arm 433 toward the lower side (side of the water tank 40). The telescopic member 434 is configured to be able to retreat from the water WA in the shallow bottom 402 (the position shown in FIG. 5) and the position where the front end enters the water WA in the shallow bottom 402 (shown in FIG. 7A Position).

The rail 42 is disposed on the shallow bottom portion 402 of the water tank 40. The rail 42 is arranged to be submerged in the water WA in the shallow bottom 402. The rail 42 is provided in the front-rear direction from the vicinity of the rear end portion of the shallow bottom portion 402 so as to protrude slightly toward the deep bottom portion 401 side. Between the rear end portion of the rail 42 and the rear wall portion of the shallow bottom portion 402, a space accessible by the telescopic member 434 is provided. Although FIG. 5 shows a rail 42 including a single wafer transfer surface 422, the entire rail 42 is submerged in water in the shallow bottom portion 402 even in the case of having a plurality of wafer transfer surfaces 422. Configured in WA.

The cassette stage lifting apparatus 412 of the cassette submerging apparatus 41 is arranged near the deep bottom 401 of the water tank 40. The cassette stage 411 is arranged at a position corresponding to the deep bottom 401. The cassette stage lifting device 412 is configured to be able to retreat the cassette C2 from the water WA in the deep bottom 401 (the position shown in FIG. 5) and to submerge a part of the cassette C2 in the deep bottom 401. The cassette table 411 is raised and lowered between positions (for example, positions shown in FIG. 7B) in the water WA. The cassette C2 is placed on the cassette table 411 with the opening portion facing the rear side.

Next, a method for carrying out the wafer W in the polishing apparatus 1 having the above-described configuration will be described with reference to FIGS. 6 and 7. 6 and 7 are schematic diagrams for explaining various steps when the wafer W is carried out in the polishing apparatus 1 according to this embodiment. In addition, in FIGS. 6 and 7, as in FIG. 5, the protective tape T is omitted, the rail 42 and a part of the underwater moving device 43 are simplified, and the components of the cassette submerging device 41 are shown in FIG. 1. The position is distorted to display.

FIG. 6A shows a holding step (hereinafter referred to as a “wafer holding step”) of holding the wafer W on the holding table 5 with the carrying-out pad 60. In this wafer holding step, the wafer W that has been subjected to polishing processing and is held on the holding table 5 is held by the carrying-out pad 60 of the carrying-out equipment 6. When the wafer W is held, as shown in FIG. 6A, the carry-out pad 60 is positioned near the holding table 5 by a lifting device 61. At this time, the holding surface 64 of the carry-out pad 60 is disposed at a position that does not contact the holding surface W1 of the wafer W although it is opposed.

By opening the valve connected to the water supply source connection portion 631 from a state close to the wafer W, water can be discharged from the drainage port 642 of the carry-out pad 60 (see FIG. 3). The water discharged from the drainage opening 642 flows along the drainage groove 643 and abuts against the inner wall surface of the guide ring 65. The water that abuts on the inner wall surface of the guide ring 65 flows out of the drainage groove 643 in the circumferential direction. Thereby, the gap between the holding surface 64 and the wafer W arranged between the adjacent drainage trenches 643 can be formed in a state of being filled with water. As a result, a water layer can be formed between the holding surface 64 of the carry-out pad 60 and the held surface W1 of the wafer W, and an adsorption force holding the wafer W can be generated in the water layer. In this state, when the suction force formed by the holding table 5 is released, the wafer W can be held on the carry-out pad 60.

Furthermore, in the wafer holding step, the slider 432 of the underwater moving device 43 is positioned at the rear end portion of the guide rail 431. The telescopic member 434 is formed in a state of retreating from the water in the shallow bottom portion 402. The cassette stage lifting apparatus 412 of the cassette submerging apparatus 41 is formed in a state where the cassette stage 411 is raised to a position where the cassette C2 retreats from the water in the deep bottom 401.

When the wafer W is held in the wafer holding step, the process moves to a step of flooding the wafer W in the water WA in the water tank 40 (hereinafter referred to as a "wafer submerging step"). FIG. 6B is an explanatory diagram of a wafer flooding step. In this wafer submerging step, the wafer W held on the carry-out pad 60 is placed on the rail 42 of the shallow bottom portion 402, and the wafer W is submerged in the water WA in the water tank 40.

The wafer W held by the carrying-out pad 60 is raised by the lifting device 61 and then wound by the winding device 62 toward the shallow bottom portion 402 side. When the carry-out pad 60 is arranged on the rail 42 in the shallow bottom portion 402, the carry-out pad 60 is lowered to the vicinity of the wafer transfer surface 422 on the rail 42 by the lifting device 61. At this time, the wafer W held in the carry-out pad 60 is formed in a state of being submerged in the water in the shallow bottom portion 402. When the carry-out pad 60 approaches the wafer transfer surface 422, the valve connected to the air supply source connection portion 632 is opened, and air is discharged from the air discharge port of the carry-out pad 60. Thereby, the wafer W can be released from the adsorption force of water generated on the transfer pad 60 and placed on the rail 42.

Furthermore, in the wafer submerging step, the slider 432 of the underwater moving device 43 moves from the rear end portion of the guide rail 431 to the front end portion in order to avoid contact with the carry-out device 6. Moreover, the states of the telescopic member 434 and the cassette stage lifting device 412 have not changed since the wafer holding step.

When the wafer W is placed on the rail 42 in the wafer submerging step, the process moves to a step of moving the wafer W toward the cassette C2 in water (hereinafter referred to as a "wafer underwater moving step"). FIG. 7A and FIG. 7B are explanatory diagrams of a moving step in a wafer. In the wafer underwater moving step, the carry-out pad 60 on which the wafer W has been carried out is wound toward the holding table 5 side, and the slider 432 is moved toward the rear end portion side of the guide rail 431.

When positioning the slider 432 to the rear end portion of the guide rail 431, the front end portion of the telescopic member 434 is extended into the water in the shallow bottom portion 402 to the vicinity of the rail 42. At this time, the front end portion of the telescopic member 434 is in a space between the rear end portion of the rail 42 and the rear wall portion of the shallow bottom portion 402 and is disposed at a position abutting on the rear end portion of the wafer W. When the protective tape T is affixed to the wafer W, the protective tape T is placed at a position where the distal end of the telescopic member 434 abuts against the edge of the protective tape T extending from the wafer W.

On the other hand, the cassette stage lifting device 412 of the cassette flooding apparatus 41 lowers the cassette stage 411 to a position where a part of the cassette C2 is submerged in the water WA in the deep bottom 401. More specifically, the cassette stage 411 is lowered until the desired shelf (for example, the lowest shelf) in the cassette C2 is formed to be the same as the wafer transfer surface 22 arranged on the rail 42. Up to the height of the position. At this time, the desired shelf in the cassette C2 is in a state of being submerged in the water WA in the deep bottom 401.

When the cassette C2 moves to a desired height, the slider 432 moves along the guide rail 431 toward the front side (the cassette C2 side). As the slider 432 moves, the telescopic member 434 pushes the wafer W on the rail 42 toward the front side. At this time, the wafer W is moved toward the cassette C2 on the wafer transfer surface 422 and in the water in the shallow bottom portion 402.

When the slider 432 moves to a certain position on the guide rail 431, as shown in FIG. 7B, the front end portion of the wafer W enters the cassette C2. By further moving the slider 432 to the front side from this state, the wafer W is completely contained in the cassette C2 from the rail 42. At this time, the wafer W moves toward the front side in the water in the deep bottom portion 401 on a desired shelf in the cassette C2. In this way, the wafer W after the polishing process can be transported to the cassette C2 by maintaining the wet state by the water WA in the water tank 40 of the storage device 17. Therefore, it is possible to prevent the wafer W from becoming dry when the wafer W is stored in the cassette C2.

When the wafer W is completely stored in the cassette C2 in the wafer water moving step, it is transferred to a step of lowering the cassette C2 in order to store the subsequent wafer W (hereinafter, referred to as a "cassette lowering step"). ). FIG. 7C is an explanatory diagram of the cassette lowering step. In this cassette lowering step, the cassette table 411 is lowered so that the upper shelf of the upper shelf that has previously contained the wafer W is stored at the same height as the wafer transfer surface 422 on the rail 42 .

Furthermore, in the cassette lowering step, the slider 432 of the underwater moving device 43 is positioned at the front end portion of the guide rail 431. The telescopic member 434 is formed in a state of retreating from the water in the shallow bottom portion 402. Then, as shown in FIG. 7C, when the holding table 5 holding the polished wafer W is positioned at the transfer position of the wafer W, the process moves to the wafer holding step, and the steps shown in FIGS. 6 and 7 can be repeatedly performed. Shown various steps.

As described above, according to the polishing apparatus 1 of this embodiment, water can be discharged radially from the center of the holding surface 64 of the carrying-out pad 60 holding the wafer W, and the holding surface 64 and the wafer W A water layer is formed between the upper surface (the holding surface W1) and the wafer W is carried out from the holding table 5. On the other hand, the wafer C is submerged in the water tank 40 in a state where the wafer W is submerged. It moves in water toward the cassette C2. Thereby, since the wafer W after the polishing process can be carried out from the holding table 5 to the storage equipment 17 in a wet state, and the wafer W can be stored in the magazine C2 in the storage state 17 in a wet state, the polishing process can be prevented. In the subsequent transfer step, the wafer W becomes dry, and it is possible to prevent the polishing slurry used in the polishing process from being fixed on the surface of the wafer W.

The present invention is not limited to the embodiments described above, and can be implemented with various modifications. In the embodiment described above, the sizes, shapes, and the like illustrated in the drawings are not limited thereto, and can be appropriately changed within a range in which the effects of the present invention can be exhibited. In addition, as long as it does not deviate from the scope of the object of the present invention, it can be implemented with appropriate changes.

For example, in the above-mentioned embodiment, the underwater moving device 43 which has the slider 432 and the telescopic member 434, and moves the wafer W toward the cassette C2 by the front-end | tip part of the telescopic member 434 is demonstrated. However, the configuration of the underwater mobile device 43 is not limited to this, and may be appropriately changed. Under the condition that the wafer W is moved to the cassette C2 side along the rail 42 as a condition, the underwater moving device 43 may be configured to generate a water flow. At this time, the underwater moving device 43 may be considered to include a nozzle that ejects fluid toward the cassette C2 side, for example. The underwater mobile device 43 is particularly preferably provided with a two-fluid nozzle or an ultrasonic water nozzle.

Moreover, in the said embodiment, the case where the cassette opened to the rear side was provided as the cassette C2 is demonstrated. However, the configuration of the cassette C2 is not limited to this configuration, and may be appropriately changed. For example, in order to maintain the wet state of the wafer W stored in the storage device 17, a configuration may be provided in which a lid that blocks the opening of the cassette C2 is provided. In this case, the wafer W can be maintained in a wet state in the cassette C2 when being carried out to another device, that is, the cleaning device, of the polishing device 1, thereby preventing the polishing slurry from being fixed on the wafer W. Superficial state of affairs. Industrial availability

As described above, the present invention has the effect of preventing the polishing slurry used in the polishing process from being fixed on the wafer, and is also performed by supplying the polishing slurry containing free abrasive particles to the polishing surface. A grinding apparatus for grinding processing is useful.

1‧‧‧ grinding device

5‧‧‧ holding table

6‧‧‧ Remove equipment

10‧‧‧ abutment

11‧‧‧ Cassette Robot

12‧‧‧ robotic arm

13‧‧‧hand

14‧‧‧ Positioning agency

15‧‧‧Temporary stand

16‧‧‧ Locating Pin

17‧‧‧Storage Equipment

20‧‧‧ Move in equipment

21‧‧‧ Move-in pad

22, 433, 63‧‧‧ arm

23‧‧‧mobile board

24‧‧‧ Waterproof cover

25‧‧‧ Pillar

26‧‧‧Grinding feed equipment

27, 431‧‧‧rail

28‧‧‧Z axis table

29‧‧‧ball screw

30‧‧‧Grinding equipment

31‧‧‧shell

32‧‧‧ Spindle Unit

33‧‧‧Grinding wheel

34‧‧‧ Spindle

35‧‧‧Mount

36‧‧‧ Abrasive Pad

40‧‧‧Sink

401‧‧‧deep bottom

402‧‧‧ shallow bottom

41‧‧‧ Cassette Submerged Equipment

411‧‧‧ cassette box

412‧‧‧ Cassette table lifting equipment

42‧‧‧ track

421‧‧‧Track components

422‧‧‧ wafer transfer surface

43‧‧‧ Water mobile equipment

432‧‧‧Slider

434‧‧‧Telescopic member

50a‧‧‧ holding surface

60‧‧‧Remove pad

61‧‧‧Lifting equipment

62‧‧‧Spinning equipment

631‧‧‧ Water supply source connection

632‧‧‧Air supply source connection

633‧‧‧Water supply pipe

634‧‧‧Air supply pipe

64‧‧‧ keep face

641‧‧‧bottom face

642‧‧‧drain

643‧‧‧ Ditch

643a‧‧‧ Top surface

65‧‧‧ guide ring

C1‧‧‧ cassette (1st cassette)

C2‧‧‧ cassette (2nd cassette)

M‧‧‧Drive motor

W‧‧‧ Wafer

W1‧‧‧ kept surface

WA‧‧‧ Water

T‧‧‧protective tape

X, Y, Z‧‧‧ directions

Y‧‧‧Y-axis direction

Z‧‧‧Z axis direction

FIG. 1 is a perspective view of a polishing apparatus according to this embodiment. FIG. 2 is a perspective view showing an external appearance of a carry-out pad included in the polishing apparatus according to this embodiment. FIG. 3 is a perspective view for explaining a holding surface of a carrying-out pad according to this embodiment. FIG. 4 is a cross-sectional view for explaining the internal structure of a carry-out pad according to this embodiment. FIG. 5 is an explanatory diagram of a configuration of a storage device included in the polishing apparatus according to this embodiment. 6A to 6B are schematic diagrams for explaining various steps when a wafer is carried out in the polishing apparatus according to this embodiment. 7A to 7C are schematic diagrams for explaining various steps when a wafer is unloaded in the polishing apparatus of this embodiment.

Claims (1)

A polishing apparatus includes a first cassette for storing wafers in a shelf-like form, a holding table for holding wafers, a loading device for transferring wafers from the first cassette into the holding table, and polishing the wafer with a polishing pad. Grinding equipment for wafers held by the holding table, carrying-out equipment for carrying out the polished wafers from the holding table, a second cassette for storing the polished wafers in the form of shelves, and the carrying-out equipment from The polished wafers carried out by the holding table are stored in a storage device of the second cassette. The carrying out device is provided with a carrying-out pad having a plate shape and radiating water radially from the center of the holding surface holding the wafer. Draining, forming a water layer between the holding surface and the upper surface of the wafer and holding the wafer, the storage device includes a water tank, a cassette submerging device for submerging the second cassette in the water in the water tank, The track that the second cassette that has been submerged in water extends to be submerged in the water tank, and the wafer is submerged in the water by the carrying device on the track, so that the wafer faces in the direction in which the track extends. The second cassette submerged in water Water in water line moving mobile device.