JP2008117844A - Wafer conveying method and processing apparatus - Google Patents

Abstract

The present invention provides a transport method and a processing apparatus provided with transport means capable of maintaining the strength of a wafer by transporting the processed wafer to the next process without deforming the wafer.
Liquid is supplied from a liquid supply nozzle to the surface of the wafer 1 that has been processed and returned to the attachment / detachment position, and then the suction surface 78a of the suction pad 78 of the recovery means is pressed against the upper surface of the wafer 1. A thin liquid film 8 is formed between the wafer 1 and the suction pad 78. Next, a charge is applied to the thermoelectric cooling element 80 provided on the suction pad 78 to cool the suction surface 78 a, the liquid film 8 is frozen, and the wafer 1 is bonded to the suction pad 78. Thereafter, the recovery arm 79 is rotated to transport the wafer 1 to a destination spinner type cleaning device and apply a charge opposite to that when the thermoelectric cooling element 80 is cooled, and the adsorption surface 78a is heated to freeze the liquid film. And the wafer 1 is moved away from the suction pad 78 and transferred into the cleaning device.
[Selection] Figure 6

Description

  The present invention relates to a conveyance method for moving a ground or polished wafer to a conveyance destination and a processing apparatus employing the method.

  Semiconductor wafers are required to be thinned along with recent miniaturization and thinning of various electronic devices. For this reason, the thickness of the semiconductor wafer is comparatively thin at 100 μm or less, and there is a problem of maintaining the strength after being formed into chips. Therefore, a technique for removing mechanical damage caused by the grinding process by polishing or etching the processed surface after the grinding process is used. In addition, in order to safely transport a thin wafer having a large diameter to the next process, a technique is also known in which the wafer is transported by a transport unit using a suction pad having the same diameter as the wafer.

JP 2000-021952 A

  As described in Patent Document 1, a porous porous vacuum suction pad made of ceramic or the like is used as a wafer transfer means provided in a wafer processing apparatus. The wafer is sucked and sucked into a large number of holes that are vacant on the suction surface of the suction pad, but may be pulled into the hole (generally about 0.1 to 0.2 mm in diameter) and elastically deformed locally. is there. If so, local stress may be applied to the wafer and the strength of the wafer may be deteriorated. This problem becomes more prominent as the wafer is thinner.

  Therefore, the present invention provides a conveying method and a processing apparatus provided with a conveying means capable of maintaining strength by conveying a wafer that has been processed without being deformed when conveying the wafer to the next process. The purpose is that.

  The wafer transport method of the present invention is a method of transporting a wafer to a predetermined transport destination after processing the wafer, a liquid supply step for supplying liquid to the surface of the processed wafer, and a wafer supplied with liquid A suction pad setting step in which a suction surface of a transport suction pad provided with a thermoelectric cooling element is pressed against the surface so that a liquid film is interposed between the suction pad and the wafer; and a thermoelectric cooling element A wafer bonding process for cooling the suction surface of the suction pad by applying a charge to the wafer and freezing the liquid film to bond the wafer to the suction pad; and a wafer transporting process for transporting the wafer by moving the suction pad to a predetermined position; And a wafer transfer step of applying a charge opposite to that at the time of cooling to the thermoelectric cooling element to melt the frozen liquid film and transferring the wafer to a predetermined transport destination. It is.

  According to the wafer transport method of the present invention, the wafer is bonded to the transport suction pad by the frozen liquid film, so that the wafer is not deformed, and therefore, the strength of the wafer as it is processed. Can be safely transported to a predetermined transport destination. This action is particularly effective when a very thin wafer (for example, a thickness of 100 μm) is conveyed. Since the suction pad is not a vacuum suction type as in the prior art, the suction pad may not be a porous body, and may be made of, for example, metal having a smooth suction surface, which can reduce the cost.

  Next, a wafer processing apparatus according to the present invention is an apparatus that can suitably carry out the transport method according to the present invention. The wafer processing apparatus adsorbs and holds the wafer, and the wafer held by the holding table is predetermined. The processing device includes processing means for performing the above processing and transport means for transporting the processed wafer from the holding table to the transport destination. The transport means includes a liquid supply means for supplying a liquid to the surface of the wafer held by the holding table, a suction pad having a suction surface pressed against the surface of the wafer held by the holding means, and the suction pad. A thermoelectric cooling element that is provided and cools the adsorption surface to a temperature at which the liquid can be frozen by applying an electric charge, and heats the frozen liquid to a temperature at which the frozen liquid can be melted; and a wafer surface held by a holding table It is characterized by comprising a suction pad that is pressed against the head and a moving means for moving the suction pad from the holding table to the transport destination.

  The processing of the present invention is grinding processing for grinding at least one surface of a wafer or polishing processing for polishing, and the processing means is grinding processing means or polishing processing means.

  According to the present invention, since there is no possibility that the wafer is deformed in a state where the wafer is attracted to the conveyance suction pad, it is possible to convey the wafer while maintaining the strength in the processed state. .

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[1] Semiconductor Wafer Reference numeral 1 in FIG. 1 indicates a disk-shaped semiconductor wafer (hereinafter abbreviated as a wafer) whose entire back surface is ground and thinned to a target thickness (for example, 50 to 200 μm). The wafer 1 is a silicon wafer or the like, and the thickness before grinding is, for example, about 800 μm. On the surface of the wafer 1, a plurality of rectangular semiconductor chips (devices) 4 are partitioned by lattice-shaped division planned lines 3. A circuit is formed. The outer peripheral edge of the wafer 1 is chamfered so as to have a semicircular cross section in order to eliminate corners and prevent damage.

  The plurality of semiconductor chips 4 are formed in a substantially circular device formation region 5 concentric with the wafer 1. The device forming region 5 occupies most of the wafer 1, and the wafer outer peripheral portion around the device forming region 5 is an annular outer peripheral region 6 in which the semiconductor chip 4 is not formed. A V-shaped notch 7 indicating the crystal orientation of the semiconductor is formed at a predetermined location on the peripheral surface of the wafer 1. The notch 7 is formed in the outer peripheral surplus region 6. The wafer 1 is finally cut and divided along the division lines 3 and is divided into a plurality of semiconductor chips 4.

  When the wafer 1 is back-ground, for the purpose of protecting the electronic circuit, a protective tape 2 is attached to the surface on which the electronic circuit is formed as shown in FIG. As the protective tape 2, for example, a structure in which an adhesive of about 5 to 20 μm is applied to one surface of a soft resin base sheet such as polyolefin having a thickness of about 70 to 200 μm is used. Affixed so that the surface of the wafer 1 faces.

[2] Grinding Device Next, a grinding device according to an embodiment for grinding the back surface of the wafer 1 shown in FIG. 1 will be described.
FIG. 2 shows the entire grinding apparatus 10, which includes a rectangular parallelepiped base 11 having a horizontal upper surface. In FIG. 2, the longitudinal direction, the width direction, and the vertical direction of the base 11 are shown as a Y direction, an X direction, and a Z direction, respectively. At one end portion of the base 11 in the Y direction, a column 12 arranged in the X direction is erected in a pair. On the base 11, a processing area 11A for grinding the wafer 1 is provided on the column 12 side in the Y direction, and the wafer 1 before processing is supplied to the processing area 11A on the side opposite to the column 12, and An attachment / detachment area 11B for collecting the processed wafer 1 is provided.
Hereinafter, the grinding area 11A and the attachment / detachment area 11B will be described.

(I) Grinding area In the grinding area 11A, a disk-shaped turntable 13 whose rotation axis is parallel to the Z direction and whose upper surface is horizontal is rotatably provided. The turntable 13 is rotated in the direction of arrow R by a rotation drive mechanism (not shown). A plurality (three in this case) of disk-shaped chuck tables 20 whose rotation axis is parallel to the Z direction and whose upper surface is horizontal are rotated at equal intervals in the circumferential direction on the outer periphery of the turntable 13. Arranged freely.

  These chuck tables 20 are of a generally known vacuum chuck type and suck and hold the wafer 1 placed on the upper surface. As shown in FIG. 3B, the chuck table 20 has a circular adsorption area 21 made of porous ceramic on the upper surface, and the wafer 1 is adsorbed and held on the upper surface 21a of the adsorption area 21. It has become so. An annular frame 22 is formed around the suction area 21, and an upper surface 22 a of the frame 22 is continuous with the upper surface 21 a of the suction area 21 and forms the same plane. Each chuck table 20 is independently rotated or rotated in one direction or both directions by a rotation drive mechanism (not shown) provided in the turntable 13, and revolves when the turntable 13 rotates. It becomes a state.

  As shown in FIG. 2, in a state where two chuck tables 20 are arranged in the X direction on the column 12 side, grinding units 30 are respectively disposed immediately above the chuck tables 20. Each chuck table 20 is positioned at three positions, that is, a grinding position below each grinding unit 30 and an attachment / detachment position closest to the attachment / detachment area 11 </ b> B by rotation of the turntable 13. There are two grinding positions, and a grinding unit 30 is provided for each of these grinding positions. In this case, the grinding position on the upstream side (back side in FIG. 2) in the transfer direction indicated by the arrow R of the chuck table 20 by the rotation of the turntable 13 is the primary grinding position, and the downstream grinding position is the secondary grinding position. .

  Each grinding unit 30 is fixed to a slider 40 attached to the column 12 so as to be movable up and down. The slider 40 is slidably mounted on a guide rail 41 extending in the Z direction, and can be moved in the Z direction by a ball screw type feed mechanism 43 driven by a servo motor 42. Each grinding unit 30 is moved up and down in the Z direction by the feed mechanism 43 and lowered to grind the exposed surface of the wafer 1 held by the chuck table 20 by a feed operation that approaches the chuck table 20.

  As shown in FIG. 3, the grinding unit 30 includes a cylindrical spindle housing 31 whose axial direction extends in the Z direction, a spindle shaft 32 coaxially and rotatably supported in the spindle housing 31, and a spindle housing. The motor 33 is fixed to the upper end of 31 and rotationally drives the spindle shaft 32, and the disk-shaped flange 34 is coaxially fixed to the lower end of the spindle shaft 32. A cup wheel 35 is detachably attached to the flange 34 by attachment means such as screwing.

  The cup wheel 35 is configured such that a plurality of grindstones 37 are annularly arranged and fixed to the lower end surface of a disk-shaped frame 36 over the entire outer periphery of the lower end surface. A cup wheel 35 including a grindstone 37 containing abrasive grains # 320 to # 400 is attached to the flange 34 of the grinding unit 30 for primary grinding disposed above the primary grinding position. Further, a cup wheel 35 having a grinding wheel 37 containing abrasive grains of, for example, # 2000 to # 8000 or more is attached to the flange 34 of the grinding unit 30 for secondary grinding disposed above the secondary grinding position. The flange 34 and the cup wheel 35 are provided with a grinding water supply mechanism (not shown) for supplying grinding water for cooling and lubrication of the grinding surface or discharging grinding scraps, and a water supply line is connected to the mechanism. Yes. The grinding outer diameter of the cup wheel 35, that is, the diameter of the outer peripheral edge of the plurality of grindstones 37 is at least equal to or larger than the radius of the wafer 1 and is generally set to a size equal to the diameter of the wafer.

  A reference numeral 50 in FIG. 3 is a thickness measurement gauge constituted by a combination of a reference side height gauge 51 and a wafer side height gauge 52. The reference-side height gauge 51 detects the height position of the upper surface 22a by the tip of the swinging reference probe 51a contacting the upper surface 22a of the frame 22 of the chuck table 20 that is not covered with the wafer 1. The wafer-side height gauge 52 detects the height position of the upper surface of the wafer 1 by contacting the tip of the oscillating variable probe 52a with the upper surface of the wafer 1 held by the chuck table 20, that is, the surface to be ground. . According to the thickness measurement gauge 50, the thickness of the wafer 1 is measured based on the value obtained by subtracting the measurement value of the reference side height gauge 51 from the measurement value of the wafer side height gauge 52.

  The wafer 1 is first ground by the grinding unit 30 at the primary grinding position, and then transferred to the secondary grinding position by the turntable 13 rotating in the R direction shown in FIG. Next is ground.

(II) Attachment / Removal Area As shown in FIG. 2, a two-bar link pickup robot 70 that moves up and down is installed at the center of the attachment / detachment area 11B. Around the pickup robot 70, a supply cassette 71, an alignment table 72, a supply means 73, a recovery means 76, a spinner type cleaning device 81, and a recovery cassette 82 are arranged counterclockwise as viewed from above. ing. The supply means 73 is made of a porous material, and includes a suction pad 74 that sucks the wafer 1 by a vacuum action on a horizontal lower surface, and a horizontal swivel-type supply arm 75 having the suction pad 74 fixed to the tip. ing. The cassettes 71 and 82 accommodate a plurality of wafers 1 in a horizontal posture and in a stacked state at regular intervals in the vertical direction, and are set at predetermined positions on the base 11.

  The recovery means 76 is configured by a combination of a liquid supply nozzle 77 shown in FIGS. 2 and 4 and a suction pad 78 and a recovery arm 79 shown in FIGS. 2 and 6A. A liquid such as pure water is supplied from the liquid supply nozzle 77 to the back surface of the wafer 1 on the chuck table 20 positioned at the attachment / detachment position. The collection means 76 has a mechanism that presses the suction surface 78a, which is the lower surface of the horizontal suction pad 78, on the upper surface of the wafer 1 in the attachment / detachment position. Is transported from the attachment / detachment position to the spinner type cleaning device 81. The suction surface 78a of the suction pad 78 is preferably flat and smooth.

  A plurality of thermoelectric cooling elements 80 are embedded in the suction pad 78 of the collection means 76 as shown in FIG. These thermoelectric cooling elements 80 are composed of Peltier elements or the like, and are uniformly arranged on the entire suction pad 78. When one charge is applied to the thermoelectric cooling element 80, the adsorption surface 78a is cooled below zero, and when a charge opposite to this charge is applied, the adsorption surface 78a is heated to a positive temperature. Has been.

The above is the configuration of the grinding apparatus 10 of the present embodiment. Next, the operation of the apparatus 10 will be described.
The wafer 1 to be ground is first taken out from the supply cassette 71 by the pickup robot 70, placed on the alignment table 72, and determined at a certain position. Next, the wafer 1 is picked up from the alignment table 72 by the supply arm 73 and placed on the chuck table 20 waiting at the attachment / detachment position with the surface to be ground (the back surface on which the semiconductor chip 4 is not formed) facing upward. Is done. The wafer 1 is transferred to the primary grinding position and the secondary grinding position in this order by the rotation of the turntable 13 in the R direction, and the surface is ground as described above by the grinding unit 30 at these grinding positions. When grinding the wafer 1, the grinding amount is controlled while measuring the thickness of the wafer 1 by the thickness measurement gauge 50 at any grinding position. The wafer 1 for which the secondary grinding has been completed is returned to the attaching / detaching position by further rotating the turntable 13 in the R direction.

  The wafer 1 on the chuck table 13 returned to the attachment / detachment position is transported to the spinner type cleaning device 81 by the recovery means 76 as follows. First, as shown in FIG. 4B, the liquid W is uniformly supplied from the liquid suction nozzle 77 to the upper surface of the wafer 1 on the chuck table 20 (liquid supply process).

  Next, as shown in FIG. 6A, the recovery arm 79 is turned to position the suction pad 78 directly above the wafer 1, and the suction pad 78 is lowered together with the recovery arm 79 from this state. The suction surface 78 a is pressed against the wafer 1. In this operation, a thin liquid film 8 is actually interposed between the suction surface 78a of the suction pad 78 and the wafer 1 by the liquid supplied onto the wafer 1 (suction pad setting step).

  Next, one charge is applied to the thermoelectric cooling element 80 to cool the suction surface 78a of the suction pad 78 to below zero. Then, the temperature of the suction surface 78a is transmitted to the liquid film 8, and the liquid film is frozen, whereby the wafer 1 is bonded to the suction pad 78 (wafer bonding step). When a sufficient time has passed for the wafer 1 to be bonded to the suction pad 78 due to the freezing action of the liquid film 8, the state is maintained and the recovery arm 79 is turned to the spinner type cleaning device 81 side to bring the wafer 1 into the cleaning device 81. The wafer is moved to a predetermined location (wafer transport process). Subsequently, the thermoelectric cooling element 80 is charged with a charge opposite to that when the liquid film 8 is cooled, and the adsorption surface 78a is heated to + temperature. Then, the temperature of the suction surface 78a is transmitted to the frozen liquid film 8, the liquid film is melted, and the wafer 1 that has been uncoupled from the suction pad 78 is transferred to a predetermined cleaning position (wafer transfer process). ).

  Thereafter, the wafer is washed with water and dried in the spinner type cleaning device 81, and then transferred and accommodated in the collection cassette 82 by the pickup robot 70. The above is the overall operation of the grinding apparatus 10 of the present embodiment, and this operation is repeated to grind a number of wafers 1 continuously.

  Now, according to the present embodiment, in the recovery means 76 that transports the wafer 1 that has been ground from the chuck table 20 to the spinner type cleaning device 81, the suction of the wafer 1 to the suction pad 78 is performed as in the conventional case. In this case, the liquid interposed between the wafer 1 and the suction pad 78 is not frozen but the liquid is frozen. That is, first, a liquid such as pure water is supplied onto the wafer 1 from the liquid supply nozzle 77, and then the suction surface 78a of the suction pad 78 is pressed against the upper surface of the wafer 1 to form the liquid film 8 between them. The adsorption surface 78 a is cooled by a plurality of thermoelectric cooling elements 80 in 78 to freeze the liquid film 8, whereby the wafer 1 is adsorbed and held on the adsorption pad 78. In addition to the pure water, a solution such as ethylene carbonate may be used as the liquid, and the freezing temperature when these solutions are used is a temperature corresponding to the characteristics of each solution.

  Even if the wafer 1 is adsorbed to the adsorbing pad 78 by such an adsorbing method, the wafer 1 is not deformed by the stress generated when adsorbed to the adsorbing pad 78 as in the prior art. For this reason, the wafer 1 can be safely transported to the spinner cleaning device 81 while maintaining the strength of the processed state.

  FIG. 5A shows a recovery means in which a conventional vacuum chuck type suction pad 84 is attached to a recovery arm 79, and the suction surface 84 a of the suction pad 84 is formed of a porous body 86. When the wafer 1 is adsorbed to the adsorbing surface 84a by a vacuum action, the wafer 1 is attracted by a large number of holes vacant in the adsorbing surface 84a of the porous body 86 as shown in FIG. Elastically deformed. As a result, local stress is applied to the wafer 1 and the strength of the wafer may be deteriorated.

  In the present embodiment, the wafer 1 is not directly adsorbed on the adsorption surface 78a of the adsorption pad 78, and the wafer 1 is bonded to the adsorption surface 78a and held by the liquid film 8 frozen between the wafer 1 and the adsorption surface 78a. For this reason, it is not caused to be deformed by being sucked into the pores of the porous body as in the prior art, and the strength can be maintained. The suction pad 78 of the present embodiment has excellent thermal conductivity such as stainless steel and aluminum, and high-rigidity sintering such as alumina ceramic and silicon carbide for promptly freezing and melting the liquid film 8. A material system is preferably used.

  In the above embodiment, the present invention is applied to a grinding apparatus, but the present invention is also applicable to a polishing apparatus as shown in FIG. In FIG. 7, the same components as those in FIG. 2 are denoted by the same reference numerals, and will be described briefly.

  The polishing apparatus 14 is for polishing and finishing the back surface of the wafer 1 ground by the grinding apparatus 10, and one column 12 is provided on which the polishing unit 60 can be moved up and down. It is installed. As shown in FIG. 8, the polishing unit 60 includes a spindle housing 31, a spindle shaft 32, a motor 33, and a flange 34 similar to those of the grinding unit 30. A polishing tool 62 is attached to the flange 34. The polishing tool 62 is formed by adhering a polishing cloth 64 impregnated with metal oxide abrasive grains such as silica to the lower surface of an annular frame 63. The frame 63 is detachably attached to the flange 34 by means such as screwing. It can be attached.

  A table base 17 is provided in the processing area 11 </ b> A of the base 11 so as to be movable in the Y direction, and a rotary chuck table 20 is mounted on the table base 17. One end of bellows-like covers 19A and 19B is attached to both ends of the table base 17 in the moving direction. The other ends of the covers 19A and 19B are the inner surface of the column 12 and the pits 18 facing the column 12, respectively. Each is attached to the inner wall surface. These covers 19 </ b> A and 19 </ b> B cover the moving path of the table base 17 and prevent the polishing dust and the like from falling on the moving path, and expand and contract as the table base 17 moves.

  In this polishing apparatus 14, the wafer held by the chuck table 20 is reciprocated between the attaching / detaching position near the attaching / detaching area 11 </ b> B and the processing position below the polishing unit 60 by the movement of the table base 17 in the Y direction. The back surface is polished by the polishing unit 60 at the processing position. After the polishing process is completed, the wafer positioned at the attachment / detachment position is adsorbed and held by the freezing of the liquid film on the suction pad 78 of the recovery means 76 in the same manner as in the above embodiment, and the recovery arm 79 rotates. It is conveyed to the spinner type cleaning device 81 where the liquid film is melted and transferred into the cleaning device 81.

Next, in order to demonstrate the effect of the conveying method of the present invention, an example in which the bending strength is measured will be shown.
First, after wafers that have been ground and thinned to a thickness of 200 μm are conveyed by the conveying method of the present invention, the bending strength of chips cut into 20 mm squares from these wafers is measured by the ball bending measurement method. did. On the other hand, as shown in FIG. 5 (a), the wafer is sucked and held on the conventional vacuum chuck suction pad, and the wafer is not sucked and held on the suction pad after grinding. The bending strength was measured in the same manner for the wafer. The number of measurement samples was 61 for each. The maximum value, the minimum value, and the average value of the bending strength of these wafers are shown in FIG.

  As is apparent from FIG. 9, the wafers conveyed by the conveying method of the present invention are not significantly changed in bending strength even when compared with the wafers not conveyed, and the high strength is maintained. I understand. On the other hand, the bending strength of the wafer conveyed by the conventional conveying method is remarkably lowered and shows a value lower than the lowest value of the wafer conveyed by the conveying method of the present invention even though it is the highest value. In the case of the present invention, the difference in intensity is 7 to 8 times that of the conventional method as an average value. Accordingly, it has been demonstrated that the strength of the wafer as it is processed can be maintained with the transport method of the present invention, although the conventional transport method has lost considerable strength.

It is the (a) perspective view and (b) side view of the wafer ground by one Embodiment of this invention. 1 is a perspective view of a grinding apparatus according to an embodiment of the present invention. It is the (a) perspective view and the (b) side view which show the state which grinds the wafer with the grinding unit with which the grinding-work apparatus of FIG. 2 is equipped. It is the (a) perspective view and (b) side view which show the liquid supply nozzle of the grinding-work apparatus of one Embodiment. (A) is a side view which shows the conventional collection | recovery means, (b) is an enlarged side view of the part which has adsorb | sucked the wafer by the means of Fig.5 (a). (A) is a side view which shows the collection | recovery means of one Embodiment of this invention, (b) is an expanded side view of the part which is adsorb | sucking a wafer with the means of Fig.6 (a). It is a perspective view of the grinding | polishing processing apparatus which shows other embodiment of this invention. It is a side view which shows the state which grind | polishes the wafer with the grinding | polishing unit with which the grinding | polishing processing apparatus of FIG. 7 is equipped. It is a diagram which shows the measurement result of the bending strength test done in the Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Semiconductor wafer 8 ... Liquid film 76 ... Recovery means (conveyance means)
77 ... Liquid supply nozzle 78 ... Adsorption pad 78a ... Adsorption surface 79 ... Recovery arm 80 ... Thermoelectric cooling element W ... Liquid

Claims (4)

A method of transporting the wafer to a predetermined transport destination after processing the wafer,
A liquid supply step for supplying liquid to the surface of the processed wafer;
A state in which a suction surface of a transport suction pad provided with a thermoelectric cooling element is pressed against the surface of the wafer supplied with a liquid, and a liquid film of the liquid is interposed between the suction pad and the wafer; A suction pad setting process,
A wafer bonding step of charging the thermoelectric cooling element to cool the suction surface of the suction pad and freezing the liquid film to bond the wafer to the suction pad;
A wafer transfer step of transferring the wafer by moving the suction pad to a predetermined position;
A wafer transfer method comprising: a wafer transfer step of applying a charge opposite to that during the cooling to the thermoelectric cooling element to melt the frozen liquid film and transferring the wafer to a predetermined transfer destination .   2. The wafer transfer method according to claim 1, wherein the processing is grinding processing for grinding at least one surface of the wafer or polishing processing for polishing. Holding means for holding the wafer;
Processing means for applying predetermined processing to the wafer held by the holding means;
A processing apparatus comprising transport means for transporting the wafer processed by the processing means from the holding means to a predetermined transport destination,
The conveying means is
Liquid supply means for supplying liquid to the surface of the wafer held by the holding means;
A suction pad having a suction surface pressed against the surface of the wafer held by the holding means;
A thermoelectric cooling element that is provided on the suction pad, cools the suction surface to a temperature at which the liquid can be frozen by application of electric charge, and heats the frozen liquid to a temperature at which the frozen liquid can be melted;
A wafer processing apparatus comprising: a moving unit that moves the suction pad from the holding unit to the transport destination.   4. The wafer processing apparatus according to claim 3, wherein the processing means is a grinding processing means for grinding at least one surface of the wafer or a polishing processing means for polishing.

Images