JP2017092397A - Wafer transfer apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wafer transfer apparatus capable of cleaning a surface of a wafer and a surface of a porous part with liquid to remove sludge during wafer transfer, and capable of retaining the moisture of the surface of the wafer and the porous part and performing transfer thereof in a stable state.SOLUTION: A wafer transfer apparatus 11 includes: suction retaining means 22 for retaining suction of a wafer W; and transfer means 23 for moving the suction retaining means 22 from a first position to a second position. The suction retaining means 22 includes: a non-contact hand 27 joined to the transfer means 23; and negative pressure generation means 28 that injects liquid 35 from a pad surface 27a of the non-contact hand 27 opposing to the wafer W, forms a liquid film by the liquid 35 and a negative pressure region on the pad surface 27 side of the non-contact hand 27 and retains the wafer W in a non-contact state on the pad surface side 27a of the non-contact hand 27.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a wafer transfer apparatus.

  2. Description of the Related Art Conventionally, a semiconductor manufacturing apparatus is known in which a semiconductor wafer (hereinafter referred to as “wafer”) is transferred between various processing steps (see, for example, Patent Document 1).

  A flat surface processing apparatus known in Patent Document 1 for grinding the back surface (one surface) of a semiconductor wafer includes a chuck that holds the wafer by suction, a rough grinding wheel, a fine grinding wheel, a polishing apparatus, and the like. Yes. According to the flat surface processing apparatus, after the wafer surface (the other surface) is sucked and held by the chuck, the rough grinding wheel is pressed against the back surface of the wafer, and the chuck and the grindstone are further moved. The back surface is roughly ground by rotating. The wafer that has been subjected to rough grinding is then finely ground by the precision grinding wheel. Further, the wafer that has been subjected to precision grinding is transferred to a cleaning device, and the back surface thereof is cleaned. Thus, the back surface grinding of one wafer by the flat surface processing apparatus is completed.

  And in the said plane processing apparatus, the wafer which the grinding process of the back surface was complete | finished is transferred to the washing | cleaning process which is the next process. That is, the wafer is sequentially moved from the first position where the back surface is ground to the second position where the next cleaning step is performed. At this time, the suction holding means for sucking and holding the wafer, and the suction holding means are changed to the first position. There is known a method of carrying using a carrying device that moves from a first position to a second position.

  FIG. 16 shows an example of a conventional back grinding apparatus (hereinafter referred to as “processing apparatus”), and FIGS. 17, 18 and 19 show an example of the conveying apparatus.

  A processing apparatus 101 shown in FIG. 16 includes a porous chuck 104 that is connected to a rotation mechanism 103 attached to the apparatus main body 102 and rotates, a grinding apparatus 105 that is provided to face the porous chuck 104, and the like. . On the other hand, the conveying device 110 shown in FIGS. 17 to 19 includes a suction holding unit 111, a conveying unit 110 that moves the suction holding unit 111 from the first position to the second position, and the like.

  The porous chuck 104 includes, for example, a ceramic porous portion 106 and a ceramic body 107. As shown in FIG. 16, the vacuum chucking (vacuum) is performed by a pipe 108 provided at the center of the body 107. A negative can be applied through the portion 106. The wafer W placed on the porous chuck 104 can be chucked by vacuum suction at the porous portion 106.

  The grinding device 105 has a grindstone 109 that rotates horizontally at the tip (lower end). Then, a grindstone 109 that is also rotated against the wafer W that rotates integrally with the porous chuck 104 is pressed, and the wafer W and the grindstone 109 are rotated to grind the back surface of the wafer W.

  The transfer device 110 shown in FIGS. 17 to 19 is movable to, for example, a first position for performing a back grinding process and a second position for performing a cleaning process, and the suction holding means is provided at a tip (lower end) portion thereof. 111 is attached.

  The suction holding means 111 is a porous chuck substantially the same as the porous chuck 104, and includes, for example, a ceramic porous portion 112 and a ceramic hand 113. Then, vacuuming is performed by the piping 114 provided in the central portion of the conveying device 110 and the hand 113, and negative pressure is applied to the lower surface of the suction holding means 111 through the porous portion 112 by vacuuming. ing. Then, the wafer W placed in a free state on the porous chuck 104 is chucked by vacuum suction by the porous portion 112, and transferred from the first position to the second position together with the transfer device 110, It can be placed on a porous chuck (not shown) provided at the second position.

  Next, the wafer W is moved from the first position where the back surface grinding is performed to the second position where the next cleaning process is performed, and is placed on a porous chuck (not shown) provided at the second position. The operation in this case will be described with reference to FIGS.

  First, as shown in FIG. 17, at the first position of the back surface grinding apparatus 101, the suction holding means 111 is disposed above the porous chuck 104 on which the wafer W after the back surface grinding process is placed by the transfer device 110. Is done. In the state of FIG. 17, sludge 115 such as grinding and polishing debris generated during grinding and a slurry liquid used during polishing is often attached to the back surface of the wafer W. Therefore, in this example, it is assumed that the sludge 115 is attached to the back surface of the wafer W.

  Further, the suction holding means 111 transported above the porous chuck 104 is lowered by the transport device 110 until the porous portion 112 is pressed against the back surface of the wafer W, as shown in FIG. Thereafter, a negative pressure is generated in the porous portion 112 to vacuum-suck the wafer W to the porous portion 112, and the wafer W is held by the chuck.

  When the suction holding (chuck) by the porous portion 112 is finished, the suction holding means 111 is moved to the second position where the cleaning process is performed together with the wafer W by the transfer device 110, and the porous chuck 104 is moved to the second position. Is pressed through the wafer W. Thereafter, as shown in FIG. 18, the release air is sent to the porous portion 112 side, the release air 116 is ejected from the porous portion 112 side, and the wafer W is peeled off from the porous portion 112. At the same time, a negative pressure is generated on the porous chuck 104 side in the second position, and the wafer W is chucked and delivered to the porous chuck 104 side in the second position. After delivery, the suction holding means 111 is returned to the first position together with the transport device 110, and this operation is repeated thereafter. Thereby, the conveyance of the wafer W from the first position to the second position is repeatedly performed. FIG. 20 is an enlarged view of part A in FIG. In FIG. 20, after the wafer W is peeled off from the porous portion 112, the sludge 115 remains attached to the back surface of the porous portion 112 and the wafer W, and the rough surface of the porous portion 112 causes the wafer W to be removed. A state in which the scratch 117 is attached to the back surface is shown.

JP2010-124006A.

However, in the conventional wafer transfer apparatus shown in FIGS. 16 to 19, since the wafer W is sucked and held on the surface of the porous portion 112 of the suction holding means 111, the following (1) to (4) There was a serious problem.
(1) When the wafer W is attracted and held, the wafer W is deformed, and a strong stress is applied to the wafer W.
(2) When the porous portion 112 having a rough surface is brought into contact with the back surface of the wafer W, the surface of the wafer W may be scratched 117 as shown in FIG.
(3) When the wafer W is processed, simple cleaning is performed, but the sludge 115 may remain without being washed off. When the sludge 115 remains, as shown in FIG. 20, when the wafer W is vacuum-sucked to the porous portion 112, the porous portion 112 sucks the sludge 115 and clogs the porous portion 112, or The sludge 115 may be transferred to the porous portion 112.
(4) Further, when the sludge 115 remains, the sludge 115 is dried and fixed on the porous portion 112 and the wafer W by vacuum suction and air blow release (release air 116) shown in FIG. It is hard to do.

  Therefore, during wafer transfer, the surface of the wafer and the surface of the porous part are washed with liquid to remove sludge, and the wafer surface and the surface of the porous part are moisturized and can be transferred in a stable state. The technical problem which should be solved in order to provide an apparatus arises, and this invention aims at solving this problem.

  The present invention has been proposed in order to achieve the above object, and the invention according to claim 1 is directed to suction holding means for sucking and holding a wafer, and the suction holding means from the first position to the second position. In the wafer transfer apparatus, the suction holding unit ejects liquid from the non-contact hand connected to the transfer unit and the lower surface of the non-contact hand facing the wafer, and the non-contact hand And a negative pressure generating means for forming a negative pressure region on the lower surface side of the liquid.

According to this configuration, when the liquid is ejected from the lower surface of the non-contact hand by the negative pressure generating means, a liquid film and a negative pressure region are formed by the liquid on the lower surface side of the non-contact hand. Then, due to the negative pressure formed on the lower surface side of the non-contact hand, the non-contact hand removes the wafer through a thin liquid film formed between the holding surface of the wafer and the pad surface of the non-contact hand. The wafer can be held in contact and the wafer can be moved from the first position to the second position together with the non-contact hand. During this movement, a liquid always flows between the non-contact hand and the wafer, and a thin liquid film is continuously formed by the liquid. Therefore,
(1) From the first position to the second position, the lower surface of the non-contact hand (hereinafter referred to as “pad surface”) and the wafer surface (hereinafter referred to as “holding surface”) may be transported in a moist state. it can.
(2) Further, the holding surface and the pad surface are simultaneously cleaned at the start of conveyance (during chuck holding) and during conveyance.
(3) By forming a thin liquid film between the pad surface and the holding surface, a thin wafer or a strongly warped wafer can be corrected to a non-warped state, and the wafer can be stabilized without applying stress to the wafer. It can be transported in the state.
(4) By forming a thin liquid film between the pad surface and the holding surface, the wafer can be transported without scratching the holding surface.
(5) By forming a thin liquid film between the pad surface and the holding surface, the liquid film serves as a cushion, and the vibration of the wafer during conveyance can be suppressed by the liquid film.

  A second aspect of the present invention provides the wafer transfer apparatus according to the first aspect, wherein the negative pressure generating means ejects the liquid radially from the lower surface of the non-contact hand.

  According to the configuration, the negative pressure formed on the back surface of the pad by the Bernoulli effect caused by the flow of the liquid is ejected radially from the negative pressure generating means between the holding surface of the wafer and the pad surface of the non-contact hand. Can be held and conveyed in a non-contact state on the pad surface of the non-contact hand.

  A third aspect of the present invention provides the wafer transfer apparatus according to the first aspect, wherein the negative pressure generating means ejects the liquid from the lower surface side of the non-contact hand in a cyclone shape.

  According to the configuration, the negative pressure formed on the pad surface by the cyclone effect caused by the flow of liquid, which is jetted in a cyclone form from the negative pressure generating means, between the holding surface of the wafer and the pad surface of the non-contact hand. Thus, the wafer can be transported while being held in a non-contact state on the pad surface of the non-contact hand.

  According to a fourth aspect of the present invention, in the configuration according to the first, second, or third aspect, the suction holding means includes a flange portion that collects the liquid and is formed in an annular shape along the outer periphery of the non-contact hand. A wafer transfer apparatus is provided.

  According to the configuration, the liquid that has flowed along the outer surface of the non-contact hand along the lower surface of the non-contact hand is collected in a collar formed in an annular shape along the outer periphery of the non-contact hand. Thereby, the collection | recovery of a liquid can be made easy.

  According to a fifth aspect of the present invention, in the configuration according to the fourth aspect, the inner diameter of the flange portion gradually increases from the lower end facing the wafer toward the non-contact hand over the entire inner surface. A wafer transfer apparatus is provided that has an inclined guide surface that is reduced to a substantially outer diameter.

  According to this configuration, the wafer sucked to the non-contact hand side is guided by the inclined guide surface and floats to the non-contact hand side, and can be accurately positioned at a predetermined position with respect to the non-contact hand. Moreover, the gap between the wafer levitated to the non-contact hand side and the heel portion can be reduced to reduce the liquid from flowing to the lower side of the wafer.

  According to a sixth aspect of the present invention, in the wafer transfer apparatus according to the fourth or fifth aspect, the first position is supplied with water from a lower surface of the wafer, and the wafer is directed toward the non-contact hand. Provided is a wafer transfer device having a water supply means that floats up to an upper part in a heel part.

  According to the configuration, the gap between the wafer and the heel part is reduced by floating the wafer to the upper part in the heel part by the water supply means at the first position. Then, when the non-contact hand holds the wafer with a negative pressure created by jetting the liquid from the negative pressure generating means, the liquid does not easily flow to the lower side of the wafer, and the negative pressure is stabilized and the chuck is surely performed. be able to.

  A seventh aspect of the present invention is the configuration according to the first, second, third, fourth, fifth or sixth aspect, wherein the suction position is held by the suction holding means at least in the second position. Provided is a wafer transfer device provided with a porous chuck for sucking and holding the wafer when the negative pressure holding for the incoming wafer is released.

  According to this configuration, the wafer held in the non-contact state by the suction holding unit and transferred from the first position to the second position by the movement by the transfer unit is then subjected to the negative pressure by the suction holding unit. When the holding is released, it is forcibly handed over to the porous chuck provided at the second position, and is securely sucked and held by the porous chuck at the second position.

According to the present invention, at the time of movement, a liquid is allowed to flow on the lower surface of the non-contact hand, and a negative pressure region for sucking and holding the wafer and a thin liquid film are formed between the lower surface and the wafer, Since the wafer is sucked and held in a non-contact state and transferred from the first position to the second position,
(1) From the first position to the second position, the pad surface of the non-contact hand and the holding surface of the wafer can be transported in a moist state without being dried.
(2) The holding surface and the pad surface can be cleaned at the same time when the transfer is started and during the transfer, and can be held without sludge.
(3) Since a thin liquid film is formed between the pad surface and the holding surface and the wafer can be chucked in a non-contact state with a non-contact hand, the wafer can be transported without scratching the holding surface. it can. Further, the formed liquid film serves as a cushion, and the vibration of the wafer during transportation can be suppressed by the liquid film, and the wafer can be transported in a stable state without giving stress to a thin wafer or a wafer with strong warpage.

1 is an overall perspective view of a wafer transfer apparatus shown as a first example according to an embodiment of the present invention. It is a figure which shows the structure of the wafer grinding stage of the wafer conveyance apparatus shown in FIG. 1 in the state before injecting a liquid. It is a figure which shows the structure of the wafer grinding stage of the wafer conveyance apparatus shown in FIG. 1 in the state immediately after ejecting the liquid. It is a figure which shows the structure of the wafer grinding stage of the wafer conveyance apparatus shown in FIG. 1 in the state immediately after spraying a liquid and the wafer was hold | maintained in the non-contact state by the non-contact hand. It is a figure which shows the structure of the wafer grinding stage of the wafer conveyance apparatus shown in FIG. 1 in the state immediately after a liquid is injected and a non-contact hand hold | maintains a wafer in a non-contact state, and starts conveyance. It is a figure which shows the structure of the wafer cleaning stage of the wafer conveyance apparatus shown in FIG. 1 in the state in which the liquid is ejected and the non-contact hand is holding the wafer in a non-contact state. FIG. 2 is a view showing the structure of a wafer cleaning stage of the wafer transfer apparatus shown in FIG. 1 in a state where liquid ejection is stopped and the wafer is held by a porous chuck of a wafer cleaning processing unit. It is a whole perspective view of the wafer conveyance apparatus shown as a 2nd example which fractures | ruptures as a 2nd Example which concerns on embodiment of this invention. It is a figure which shows the internal structure of the suction holding means in the wafer conveyance apparatus shown in FIG. FIG. 10 is a perspective view of the non-contact holding pad shown in FIG. 9. It is a figure which shows the structure of the wafer grinding stage of the wafer conveyance apparatus shown in FIG. 9 in the state before injecting a liquid. It is a figure which shows the structure of the wafer grinding stage of the wafer conveyance apparatus shown in FIG. 9 in the state immediately after spraying a liquid and the wafer was hold | maintained in the non-contact state by the non-contact hand. It is a figure which shows the structure of the wafer grinding stage of the wafer conveyance apparatus shown in FIG. 9 in the state immediately after a liquid is injected and a non-contact hand hold | maintains a wafer in a non-contact state, and starts conveyance. FIG. 10 is a diagram showing a state immediately before the non-contact hand shown in FIG. 9 holds the wafer in a non-contact state and is held by the porous chuck of the wafer cleaning processing unit. FIG. 10 is a view showing the non-contact hand shown in FIG. 9 in a state after the wafer is held by the porous chuck of the wafer cleaning processing unit. It is a side view which fractures | ruptures and shows an example of the conventional processing apparatus. It is a figure which shows the structure of the grinding stage in the conventional processing apparatus shown in FIG. 16 in the state before a suction holding means hold | maintains a wafer. It is a figure which shows the structure of the grinding stage in the conventional processing apparatus shown in FIG. 16 in the state immediately after the suction holding means hold | maintained the wafer. FIG. 17 is a view showing the structure of the cleaning stage in the conventional processing apparatus shown in FIG. 16 in a state immediately after the suction holding means delivers the wafer to the porous part of the wafer cleaning stage. It is the A section expanded sectional view of FIG.

  The present invention cleans the surface of the wafer and the surface of the porous portion with a liquid to remove sludge during wafer transfer, keeps the surface of the wafer and the surface of the porous portion moist, and enables the wafer to be transferred stably. In order to achieve the object of providing a transfer apparatus, a wafer transfer apparatus comprising: suction holding means for sucking and holding a wafer; and transfer means for moving the suction holding means from a first position to a second position The suction holding means ejects liquid from a non-contact hand connected to the transport means and a lower surface of the non-contact hand facing the wafer, and a liquid film and a negative pressure by the liquid are applied to the lower surface side of the non-contact hand. And a negative pressure generating means for forming a region.

  Hereinafter, two preferred examples of a wafer transfer apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 15.

  1 to 7 show a first example of a wafer conveyance device according to an embodiment of the present invention, and FIG. 1 is an overall perspective view of the wafer conveyance device. The wafer transfer device 11 in FIG. 1 is formed across the grinding processing unit 12 and the cleaning processing unit 13 in the semiconductor manufacturing apparatus 10. The grinding unit 12 which is the first position is provided with a grinding device 14 and a porous chuck 15, and the cleaning unit 13 which is the second position is provided with a cleaning device 16 and a porous chuck 17. ing.

  In the grinding part 12, a grindstone 19 that rotates horizontally is attached to the tip of a grinding device 14 that is disposed to face the porous chuck 15. Further, the porous chuck 15 of the grinding unit 12 can be moved horizontally to a grinding position corresponding to the grinding wheel 19 of the grinding device 14 in the vertical direction, and to a transportable position deviating from a position directly below the grinding device 14. Yes. In FIG. 1, the porous chuck 15 is shown in a state where it has been moved to a transportable position. In the grinding unit 12, the rotating grindstone 19 is pressed against the wafer W rotating with the porous chuck 15, and the wafer W and the grindstone 19 are rotated to grind the back surface of the wafer W. Yes.

  The cleaning processing unit 13 is provided with the cleaning device (detailed structure is omitted) 16 and a porous chuck 17 provided in the cleaning device 16. In the cleaning processing unit 13, the back surface of the wafer W which is transferred to the cleaning device 16 through the grinding processing in the grinding processing unit 12 and set on the porous chuck 17 in the cleaning device 16 can be cleaned. It is like that.

  The wafer transfer device 11 includes a suction holding means 22 for sucking and holding the wafer W, and a transfer means for reciprocating the suction holding means 22 from a first position (grinding position) to a second position (grinding position). 23.

  As shown in FIG. 1, the transport means 23 includes an X-axis direction guide portion 24 that can reciprocate the suction holding means 22 in the X-axis direction (the horizontal direction connecting the first position and the second position), and a suction unit. The holding means 22 has a Y-axis direction guide portion 25 that can reciprocate in the Y-axis direction (vertical direction). And the suction holding means 22 can be moved to an up-down direction, when the conveyance means 23 operate | moves in a Y-axis direction. Further, when the conveying means 23 operates in the X-axis direction, the suction holding means 22 is moved in the horizontal direction, and the suction holding means 22 is moved from the first position to the second position and to the second position. To the first position.

  As shown in detail in FIGS. 2 to 7, the suction holding means 22 includes a holding main body portion 26 connected to the Y-axis direction guide portion 25 of the conveying means 23, and a distal end portion (lower end portion) of the holding main body portion 26. ) And a negative pressure generating means 28 provided in the non-contact hand 27.

  The non-contact hand 27 is formed in a substantially disc shape as shown in FIG. Further, as shown in FIGS. 2 to 7, the non-contact hand 27 is a concave curved surface having a conical cross section in which the lower surface facing the wafer W is inclined so as to rise gently from the outer peripheral side toward the center side. That is, it has a pad surface 27a. Further, a central through hole 29 penetrating vertically is provided in the central portion of the non-contact hand 27. An air pipe 30 provided through the inside of the holding main body portion 26 is attached to one end side (the side opposite to the pad surface 27 a) of the central through hole 29. On the other hand, on the other end side (pad surface 27 a side), a central cylindrical portion 31 having a short cylindrical shape smaller than the outer diameter of the wafer W is provided, and a central through hole 29 is formed on the outer periphery of the central cylindrical portion 31. A plurality of water ejection holes 37 communicating with each other are formed radially away from each other. The plurality of water ejection holes 37 eject a liquid 35, which will be described later, sent from the air pipe 30 from the peripheral surface of the central cylindrical portion 31 at a substantially right angle and as a whole in a radial manner, so that the non-contact hand 27 A thin liquid film is formed by the flow body 35 on the lower surface side, that is, the pad surface 27a, and a negative pressure region for sucking and holding the wafer W on the pad surface 27a side is formed, and the wafer is interposed through the liquid film. The negative pressure generating means 28 for holding W on the pad surface 27a of the non-contact hand 27 in a non-contact state is formed. In addition, the center cylindrical part 31 is provided in the state accommodated in the concave curved surface of the non-contact hand 27, as shown in FIG. 2 thru | or FIG.

  The air pipe 30 is connected to a liquid storage tank (not shown) capable of supplying the liquid 35 such as water (pure water) at a high pressure, and a high-pressure liquid is supplied from the liquid storage tank. It is ejected from a plurality of water ejection holes 37 (see FIG. 2) through the central through hole 29, and can be discharged from the outer surface side of the non-contact hand 27 along the surface of the pad surface 27a. The plurality of water ejection holes 37 provided in the central cylindrical portion 31 are controlled so that the flow of the liquid 35 is ejected radially from the center of the lower surface toward the outside. The liquid 35 ejected from the central through hole 29 through the plurality of water ejection holes 37 is thin between the pad surface 27a of the non-contact hand 27 and the holding surface of the wafer W along the pad surface 27a. The liquid film is formed and flows radially. Therefore, in this embodiment, a negative pressure region is formed on almost the entire pad surface 27a by the Bernoulli principle by the flow of the liquid 35, and the wafer W is transferred to the pad surface 27a of the non-contact hand 27 and the wafer by the negative pressure. A so-called Bernoulli-type non-contact chuck that sucks the pad surface 27a in a non-contact state through a thin liquid film formed between the W holding surface and the W holding surface is formed.

  The porous chuck 15 and the porous chuck 17 have substantially the same structure. The porous chucks 15 and 17 are composed of, for example, a ceramic porous portion 32 and a ceramic body 33. The air pipe 34 provided in the central portion of the body 33 is vacuumed at the time of chucking, and the wafer W is porous. It is chucked on the chuck 15 and the release air 36 (see FIG. 4) is supplied at the time of release.

  Next, in the semiconductor manufacturing apparatus 10 configured as described above, the wafer conveyance for conveying the wafer W to the cleaning processing unit 13 which is the second position after finishing the grinding process in the grinding processing unit 12 which is the first position. An example of the conveying operation of the apparatus 11 will be described in order with reference to FIGS.

  First, the porous chuck 15 that chucks the wafer W that has been ground has been moved to a transferable position away from the grinding device 14 as shown in FIG.

  FIG. 2 shows a state in which the porous chuck 15 on which the wafer W after grinding is placed is disposed at the transportable position in the grinding part 12. Here, description will be made assuming that the sludge 20 is attached to the back surface of the wafer W or the like.

  Then, as shown in FIG. 2, the suction holding means 22 transported above the porous chuck 15 is arranged so that the pad surface 27 a of the non-contact hand 27 approaches the back surface of the wafer W in a non-contact state by the transport means 23. . In this state, the suction chuck to the wafer W on the porous chuck 15 side is also removed.

  Next, as shown in FIG. 3, water, which is the liquid 35 supplied through the air pipe 30, passes through the central through hole 29 and the water ejection hole 37, that is, from the negative pressure generating means 28 along the pad surface 27a. Injected radially from the center (center cylindrical portion 31) to the outside. The sludge 20 attached to the back surface of the wafer W and the body 33 is washed by the flow of the liquid 35, and the sludge 20 is discharged to the outer peripheral side of the wafer W and the outer peripheral side of the porous chuck 15 to be discharged and removed. Is done.

  Further, when filled with the jet water from the negative pressure generating means 28, a negative pressure region is formed on the entire pad surface 27 a of the non-contact hand 27. Then, due to the negative pressure in the negative pressure region, as shown in FIG. 4, the wafer W on the porous chuck 15 is placed on the pad surface 27a side of the non-contact hand 27 with a thin water film (liquid film 35a) interposed therebetween. It is sucked and held in the state. At this time, the release air 36 is supplied from the porous chuck 15 side. The release air 36 is not necessarily required as long as the wafer W can be easily peeled off from the porous chuck 15 only by suction by the negative pressure generating means 28.

  Further, the negative pressure region is formed on the entire pad surface 27a of the non-contact hand 27, and the wafer W on the porous chuck 15 is moved by the negative pressure in the negative pressure region as shown in FIG. The suction holding means 22 is moved upward by the conveying means 23 as shown in FIG. 5, and then the cleaning processing portion at the second position is held while being sucked and held on the pad surface 27a side of 13 is moved. Then, as shown in FIG. 6, the wafer W attracted to the pad surface 27 a of the non-contact hand 27 is disposed close to the porous chuck 17 of the cleaning processing unit 13.

  Thereafter, the supply of the liquid 35 from the tube body 30 is cut off. When the supply of the liquid 35 is cut off, the negative pressure generated by the negative pressure generating means 28 disappears, and the negative pressure on the pad surface 27a of the non-contact hand 27 is released as shown in FIG. Then, the wafer W held in a non-contact manner on the pad surface 27 a of the non-contact hand 27 is dropped onto the porous chuck 17 of the cleaning processing unit 13 and transferred to the porous chuck 17. At this time, if a negative pressure is generated on the porous chuck 17 side, the wafer W can be smoothly transferred from the pad surface 27 a of the non-contact hand 27 to the porous chuck 17 side of the cleaning processing unit 13.

  Therefore, in the wafer transport apparatus configured as described above, the negative pressure generating means 28 forms a negative pressure region on the lower surface side (pad surface 27a) of the non-contact hand 27 and the negative pressure in the negative pressure region. The non-contact hand 27 holds the wafer W in a non-contact state via a thin liquid film 35a formed between the holding surface of the wafer W and the pad surface 27a of the non-contact hand 27, and the first position To the second position. During this movement, the liquid 35 is caused to flow between the non-contact hand 27 and the wafer W, and the liquid 35 simultaneously cleans the holding surface of the wafer W and the pad surface 27a of the non-contact hand 27 to remove the sludge 20. It can be kept in a lost state. Further, a thin liquid film 35a is always formed between the pad surface 27a of the non-contact hand 27 and the holding surface of the wafer W, and the wafer W is brought into contact with the pad surface 27a through the thin liquid film 35a. Can be chucked. Thereby, it is possible to stably carry the wafer W without scratching the holding surface. Further, the liquid film 35a serves as a cushion, and the liquid film 35a can suppress the vibration of the wafer W during the transfer, and the thin wafer W and the wafer W having a strong warp can be transferred in a stable state without applying stress. It becomes possible.

  In the first embodiment, the central through hole 29 and the cylindrical portion 31 forming the negative pressure generating means 28 are disclosed in one central portion of the non-contact hand 27. The hole 29 and the cylindrical portion may be provided not only in one central portion but also in a plurality of locations on the pad surface 27a, for example, in an annular manner.

  Also, a configuration has been disclosed in which a Bernoulli-type non-contact chuck is formed and the wafer W is sucked and held on the pad surface 27a of the non-contact hand 27. However, instead of this configuration, a plurality of water ejection holes 37 are arranged. Alternatively, a water ejection hole 37 or the like may be provided so that the pad surface 27a is ejected from the center side toward the outside in a cyclone shape, and may be configured as a cyclone type non-contact chuck. In this configuration, the liquid 35 ejected through the central through hole 29 and the water ejection hole 37 flows in a cyclone shape below the pad surface 27a. And the negative pressure area | region which generate | occur | produces the negative pressure which attracts | sucks the wafer W to the pad surface 27a side is formed in the lower surface side of the pad surface 27a by the cyclonic flow. Then, the negative pressure causes the pad surface 27a to suck and hold the wafer W in a non-contact state through a thin liquid film 35a formed between the pad surface 27a and the holding surface of the wafer W.

  Furthermore, in the first embodiment, the negative pressure generating means 28 has been disclosed as having a central through hole 29 and a plurality of water ejection holes 37. However, the shape of the central through hole 29 and the water ejection holes 37 and The radial position or the cyclonic flow of the liquid 35 may be formed by changing the arrangement position or the number of arrangement.

  8 to 15 show a second example of the wafer conveyance device according to the embodiment of the present invention. FIG. 8 is an overall perspective view of the wafer conveyance device. The wafer transfer device 51 in FIG. 8 is formed across the grinding processing portion 52 and the cleaning processing portion 53 in the semiconductor manufacturing apparatus 50. The grinding unit 52, which is the first position, is provided with a grinding device 54 and a porous chuck 55, and the cleaning unit 53, which is the second position, is provided with a cleaning device 56 and a porous chuck 57. ing. Further, a suction source 80 and a water supply source 81 are installed in the wafer transfer device 51.

  In the grinding part 52, a grindstone 59 that rotates horizontally is attached to the tip of a grinding device 54 that is disposed to face the porous chuck 55. In addition, the porous chuck 55 of the grinding unit 52 can move horizontally to a grinding position corresponding to the grinding wheel 59 of the grinding device 54 in the vertical direction and to a transportable position that is off the position directly below the grinding device 54. Yes. In FIG. 8, the porous chuck 55 is shown in a state where it has been moved to the transportable position. In the grinding unit 52, the rotating grindstone 59 is pressed against the wafer W rotating together with the porous chuck 55, and the wafer W and the grindstone 59 are rotated to grind the back surface of the wafer W. Yes.

  The cleaning processing unit 53 is provided with the cleaning device (detailed structure is omitted) 56 and a porous chuck 57 provided in the cleaning device 56. In the cleaning processing unit 53, the back surface of the wafer W that has been transferred to the cleaning device 56 through the grinding processing in the grinding processing unit 52 and set on the porous chuck 57 in the cleaning device 56 can be cleaned. It is like that.

  The wafer transfer device 51 includes a suction holding means 62 for sucking and holding the wafer W, and a transfer means 63 for moving the suction holding means 62 from a first position (grinding position) to a second position (grinding position). And.

  As shown in FIG. 8, the transport means 63 includes an X-axis direction guide portion 64 capable of reciprocating the suction holding means 62 in the X-axis direction (the horizontal direction connecting the first position and the second position), and a suction mechanism. The holding means 62 has a Y-axis direction guide portion 65 capable of reciprocating in the Y-axis direction (vertical direction). Then, the suction and holding unit 62 is moved in the vertical direction by the transport unit 63 operating in the Y-axis direction. Further, when the conveying means 63 operates in the X-axis direction, the suction holding means 62 is moved in the horizontal direction, and the suction holding means 62 is moved from the first position to the second position and to the second position. To the first position.

  As shown in detail in FIGS. 9 to 15, the suction holding means 62 includes a holding main body 66 connected to the Y-axis direction guide 65 of the conveying means 63, and a tip end (lower end) of the holding main body 66. ) And a negative pressure generating means 78 provided in the non-contact hand 67.

  The non-contact hand 67 is formed in a substantially disc shape as in the case of the first embodiment shown in FIG. As shown in FIGS. 9 to 15, the non-contact hand 67 includes a base 167, a non-contact pad 267, and a cover 367 as a collar portion.

  The base 167 is formed as a disk-shaped plate member having an outer diameter substantially equal to the outer diameter of the wafer W, and a water supply pipe mounting hole 167a to which one end side of the water supply pipe 68a is inserted and attached at the center. Is provided. Further, on the back surface (lower surface side) of the base 167 facing the wafer W, a pad housing recess 167b attached in a state where the non-contact pad 267 is housed and fixed is provided concentrically with the water supply pipe mounting hole 167a. ing.

  The non-contact pad 267 is shown as a single unit in FIG. The configuration of the non-contact pad 267 will be described in detail with reference to FIG. 10 and FIGS. 11 to 15. The non-contact pad 267 housed and attached in the pad housing recess 167b is a pad holding facing the wafer W. The central portion 267b of the pad holding surface 267a is left in a columnar shape on the surface (lower surface) 267a side, and the outer portion of the central portion 267b (hereinafter referred to as “central cylindrical portion 267b”) is connected to the non-contact pad 267. A concave curved surface 267c having a generally dome-shaped cross section is provided, which gradually rises from the outer peripheral side to the outer periphery of the central cylindrical portion 267b. Therefore, the heights of the lower surfaces of the pad holding surface (lower surface) 267a and the central cylindrical portion 267b are the same. Further, the thickness of the non-contact pad 267 is equal to the depth inside the pad housing recess 167b. Accordingly, the non-contact pad 267 housed in the pad housing recess 167b is disposed substantially flush with the lower surface of the base 167. Further, in the non-contact pad 267, the water supply pipe mounting corresponding to the water supply pipe mounting hole 167a of the base 167 is formed as a recess not penetrating from the upper surface (the surface facing the base 167) into the central cylindrical portion 267b. A hole 267d is provided. In the central cylindrical portion 267b, a plurality of water ejection holes 267e extending from the outer peripheral surface to the inside of the water supply pipe mounting hole 267d are radially formed apart from each other. The plurality of water ejection holes 267e ejects a liquid 75, which will be described later, sent from the water supply pipe mounting hole 167a substantially radially from the peripheral surface of the central cylindrical portion 267b, and radially as a whole. A thin liquid film is formed by the liquid 75 on the lower surface side of the contact hand 67, that is, the pad holding surface 267a of the non-contact pad 267, and a negative pressure region for sucking and holding the wafer W toward the pad holding surface 267a is formed. The negative pressure generating means 78 for holding the wafer W in a non-contact state via the liquid film is formed on the pad holding surface 267a of the non-contact hand 67.

  One end side of the water supply pipe 68a is connected to the water supply pipe mounting hole 267d, and the other end side is a liquid storage that can supply the liquid 75 such as water (pure water) at a high pressure as shown in FIG. It is connected to a water supply source 81 such as a tank (not shown). The water supply pipe 68a is supplied with a high-pressure liquid 75 from the water supply source 81 when it is necessary to transport the wafer W, and is injected through the water supply pipe attachment hole 267d and the water ejection hole 267e. The liquid 75 can be discharged radially from the outer periphery of the non-contact holding pad 267 along the concave curved surface 267c and the pad holding surface 267a. Even in the case of the second embodiment, the liquid 75 ejected from the water ejection hole 267e forms a thin liquid film between the pad holding surface 267a of the non-contact holding pad 267 and the holding surface of the wafer W. Flowing radially. In addition, a negative pressure region is formed on almost the entire pad surface 267a by the Bernoulli principle by the flow of the radial liquid 75, and the negative pressure causes the wafer W to move between the pad holding surface 267a of the non-contact hand 67 and the wafer W. A so-called Bernoulli type non-contact chuck that sucks the pad holding surface 267a in a non-contact state via a thin liquid film formed between the holding surface and the holding surface is formed.

  The cover 367 (hereinafter referred to as a “ridge 367”) as a flange includes a donut-shaped upper surface portion 367a that covers the outer peripheral portion of the upper surface of the base 167 and is fixedly attached to the base 167, and an upper surface portion thereof. An outer peripheral cylindrical portion 367b bent at a substantially right angle from the outer peripheral end of 367a toward the lower side (porous chuck 55 side), and an outer peripheral end of the base 167 at a substantially right angle from the lower end of the outer peripheral cylindrical portion 367b to the inner side. And a donut-shaped lower surface portion 367c bent to a corresponding position, and an inner peripheral cylindrical portion 367d bent upward from the inner peripheral end of the lower surface portion 367c to the vicinity of the lower surface of the base 167. ing.

  Note that the inner diameter of the inner peripheral cylindrical portion 367d of the flange portion 367 is larger at the lower end side (porous chuck 55 side) than the outer diameter of the wafer W, and the upper surface side (base 167 side) is slightly smaller than the outer diameter of the wafer W. The inner diameter gradually increases from the lower end side facing the wafer W toward the upper end side (base 167d side) over the entire circumference of the wafer. It has been reduced to a size that is approximately approximate. That is, the inner peripheral cylindrical portion 367d of the flange portion 367 forms an inclined guide surface in which the inner diameter gradually decreases from the lower end facing the wafer W toward the base 167d to the substantially outer diameter of the wafer W. Therefore, in the following description, the inner peripheral cylindrical portion 367d of the flange portion 367 will be described as an inclined guide surface 367d.

  As shown in FIGS. 11 to 13, the porous chuck 55 includes, for example, a ceramic porous portion 55a and a body 55b. At the center of the body 55b, one end of a water supply pipe 68b and one end of an air pipe 69a. Are connected to each other. The other end of the water supply pipe 68 b is connected to the water supply source 81. The water supply pipe 68b is supplied with a high-pressure liquid 75 from a water supply source 81 when it is necessary to transport the wafer W. When the liquid 75 is supplied, the liquid 75 is supplied to the porous portion 55a. The liquid W is sprayed to the lower surface of the wafer W, and the buoyancy is acted upon by the spray of the liquid 75 so that the wafer W can be lifted from the body 55b. On the other hand, the other end of the air pipe 69 a is connected to the suction source 80. When the wafer W needs to be chucked, the air piping 69a is given a vacuum pulling force by the suction source 80 so that the wafer W can be chucked on the porous portion 55a.

  As shown in detail in FIGS. 14 and 15, the porous chuck 57 is composed of, for example, a ceramic porous portion 57a and a body 57b, and one end of an air pipe 69b is connected to the central portion of the body 57b. Is provided. The other end of the air pipe 69b is connected to the suction source 80. When the wafer W needs to be chucked, the air piping 69b is given a vacuum pulling force by the suction source 80 so that the wafer W can be chucked on the porous portion 57a.

  Next, in the semiconductor manufacturing apparatus 50 configured as described above, the wafer that transports the wafer W to the cleaning processing unit 53 that is the second position after finishing the grinding processing in the grinding processing unit 52 that is the first position. An example of the transport operation of the transport device 51 will be described in order using FIGS. 11 to 15 and FIGS. 8 to 10 as necessary.

  First, as shown in FIG. 8, the porous chuck 55 that chucks the wafer W that has been ground is moved to a transferable position away from the grinding device 54.

  FIG. 11 shows a state in which the ground wafer W is disposed on the porous chuck 55 at the transportable position in the grinding section 52. In the porous chuck 55, the wafer W is suction chucked by the porous portion 55a by suction from the suction source 80.

  Then, as shown in FIG. 12, the suction holding means 62 conveyed above the porous chuck 55 by the conveying means 63 has the non-contact holding pad 267 side of the non-contact holding pad 267 on the back surface of the wafer W. The non-contact hand 67 is put on the porous chuck 55 so as to be closely arranged in a non-contact state. In this state, the air suction on the porous chuck 55 side is cut off, and the suction restraint on the wafer W is also removed.

  Next, as shown in FIG. 12, the porous chuck 55 is supplied with water from the water supply source 81 through the water supply pipe 68b until the wafer W approaches the non-contact holding pad 267 in the flange 367, that is, the upper end of the inclined guide surface 367d. Float until it is almost the same height as the part. At the same time, water is supplied to the non-contact holding pad 267 from the water supply source 81 through the water supply pipe 68b. Due to the water supply, the liquid 75 is sprayed radially along the pad holding surface 267a from the center toward the outside on the lower surface of the contact holding pad 267 by the negative pressure generating means 78, and the pad holding surface of the non-contact holding pad 267. A negative pressure region is formed in the entire 267a. Then, due to the negative pressure in the negative pressure region, the wafer W is sucked and held on the pad holding surface 267a side of the non-contact hand 67 through a thin water film (liquid film 75a) therebetween. Thereby, the wafer W on the porous chuck 55 can be smoothly delivered to the non-contact hand 67 side of the suction holding means 62. Thereafter, on the porous chuck 55 side, the supply of the liquid 75 from the water supply pipe 68b is cut off. The supply of the liquid 75 is cut off.

  Here, the liquid 75 discharged vigorously from the non-contact holding pad 267 in the process of holding the wafer W passes over the wafer W, enters the groove 367e of the flange 367 while washing off the sludge, and further, It drains to the outside through the drainage port 367f. Further, the floating of the wafer W from the porous chuck 55 side is guided to the inclined guide surface 367d and moved to the center position of the non-contact holding pad 267. Furthermore, since the wafer W floats up to the substantially same height as the upper end portion of the inclined guide surface 367d, the liquid 75 from the non-contact holding pad 267 does not flow around the back surface side of the wafer W. Then, it surely flows into the groove 367e and is collected through the drain port 367f.

  When the wafer W is sucked and held on the non-contact hand 67 side, the suction holding means 62 is moved upward by the transfer means 63 while holding the state as shown in FIG. It is moved to the cleaning processing unit 13 which is the position. Then, as shown in FIG. 14, the wafer W sucked and held by the non-contact hand 67 is disposed close to the porous chuck 57 of the cleaning processing unit 53.

  Thereafter, on the non-contact hand 67 side, the supply of the liquid 75 is finally cut off while gradually reducing the supply amount of the liquid 75 from the water supply pipe 68a to reduce the negative pressure due to the Bernoulli effect. When the supply of the liquid 75 on the non-contact hand 67 side is cut off, the negative pressure formed by the negative pressure generating means 78 is also lost. Then, the wafer W held in a non-contact manner on the pad holding surface 267 a of the non-contact hand 67 is dropped onto the porous chuck 57 of the cleaning processing unit 53 and transferred to the porous chuck 57. Further, the upper surface of the wafer W placed on the porous chuck 57 forms a liquid film (75a) and is moisturized.

  Next, as shown in FIG. 15, the wafer W is sucked and held on the porous portion 82 by suction of air by the suction source 80 in the porous chuck 57. The non-contact hand 67 that has finished delivering the wafer W is raised to a predetermined position by the transfer means 63 and then returned toward the cutting unit 52, and this operation is repeated thereafter.

  Therefore, in the wafer transfer apparatus in the second embodiment configured as described above, the negative pressure generating means 78 forms a negative pressure region on the lower surface side (pad holding surface 267a) of the non-contact hand 67, and Due to the negative pressure in the negative pressure region, the non-contact hand 67 holds the wafer W in a non-contact state via a thin liquid film 75 a formed between the holding surface of the wafer W and the non-contact hand 67. It can be moved from the first position to the second position. During this movement, a liquid 75 is caused to flow between the non-contact hand 67 and the wafer W, and the holding surface of the wafer W and the lower surface of the non-contact hand 67 are simultaneously cleaned by the liquid 75 to eliminate sludge. Can be held in. Further, a thin liquid film is always formed between the pad holding surface 267a of the non-contact hand 67 and the holding surface of the wafer W, and the wafer W is brought into contact with the pad holding surface 267a through the thin liquid film 75a. Can be chucked. Thereby, it is possible to stably carry the wafer W without scratching the holding surface. Further, the liquid film 75a serves as a cushion, and the liquid film 75a can suppress the vibration of the wafer W during the conveyance, and the thin film W and the wafer W having a strong warp can be conveyed in a stable state without giving stress. It becomes possible to do.

  It should be noted that the present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

  Although this invention demonstrated the case where a wafer is conveyed in a semiconductor manufacturing apparatus, it is applicable also to the apparatus etc. which convey a thin board other than a semiconductor manufacturing apparatus, for example.

DESCRIPTION OF SYMBOLS 10 Semiconductor manufacturing apparatus 11 Wafer transfer apparatus 12 Grinding part (1st position)
13 Cleaning section (second position)
14 Grinding device 15 Porous chuck 16 Cleaning device 17 Porous chuck 19 Grinding wheel 20 Sludge 22 Suction and holding means 23 Conveying means 24 X-axis direction guide part 25 Y-axis direction guide part 26 Non-contact hand part 27 Non-contact hand 27a Pad surface 28 Negative pressure generation Means 29 Central through hole 30 Water supply pipe 31 Central cylindrical part 32 Porous part 33 Body 34 Air pipe 35 Liquid 35a Liquid film 36 Release air 37 Water ejection hole 50 Semiconductor manufacturing apparatus 51 Wafer transfer apparatus 52 Grinding part (first position)
53 Cleaning section (second position)
54 Grinding device 55 Porous chuck 55a Porous part 55b Body 56 Cleaning device 57 Porous chuck 57a Porous part 57b Body 59 Grinding wheel 20 Sludge 62 Suction holding means 63 Conveying means 64 X-axis direction guide part 65 Y-axis direction guide part 66 Holding body part 67 Non-contact hand 167 Base 167a Water supply piping mounting hole 167b Pad receiving recess 267 Non-contact holding pad 267a Pad holding surface 267b Center part (central cylindrical part)
267c Concave surface 267d Water supply pipe mounting hole 267e Water ejection hole 367 Cover (saddle)
367a Upper surface part 367b Outer peripheral cylinder part 367c Lower surface part 367d Inner peripheral cylinder part (inclined guide surface)
367e Groove 367f Drain port 68a Water supply pipe 68b Water supply pipe 69a Air pipe 69b Air pipe 75 Liquid 75a Liquid film 78 Negative pressure generating means 80 Suction source 81 Water supply source 82 Porous part 83 Body W Wafer

Claims (7)

In a wafer transfer apparatus comprising: a suction holding unit that sucks and holds a wafer; and a transfer unit that moves the suction holding unit from the first position to the second position.
The suction holding means includes
A non-contact hand connected to the conveying means;
Negative pressure generating means for injecting liquid from the lower surface of the non-contact hand facing the wafer and forming a liquid film and a negative pressure region by the liquid on the lower surface side of the non-contact hand;
A wafer transfer apparatus.   The wafer transfer apparatus according to claim 1, wherein the negative pressure generating unit ejects the liquid radially from a lower surface of the non-contact hand.   The wafer transfer apparatus according to claim 1, wherein the negative pressure generating unit ejects the liquid in a cyclone shape from a lower surface of the non-contact hand.   4. The wafer transfer apparatus according to claim 1, wherein the suction holding unit includes a flange portion that is formed in an annular shape along an outer periphery of the non-contact hand and collects the liquid. 5. .   The flange portion forms an inclined guide surface whose inner diameter is gradually reduced to the substantially outer diameter of the wafer from the lower end facing the wafer toward the non-contact hand over the entire inner surface. The wafer transfer apparatus according to claim 4, wherein:   6. The water supply means for supplying water from the lower surface of the wafer to the first position so as to float the wafer toward the upper part in the flange part toward the non-contact hand. The wafer conveyance apparatus as described in.   At least the second position is provided with a porous chuck for sucking and holding the wafer when the negative pressure holding for the wafer held by the suction holding means and carried by the carrying means is released. The wafer transfer apparatus according to claim 1, 2, 3, 4, 5, or 6.

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