JP4847353B2 - Wafer processing equipment - Google Patents

Description

  The present invention relates to a wafer processing apparatus such as a polishing apparatus for polishing a wafer such as a semiconductor wafer.

  In the semiconductor device manufacturing process, a plurality of regions are partitioned by dividing lines called streets arranged in a lattice pattern on the surface of a substantially wafer-shaped semiconductor wafer, and devices such as ICs, LSIs, etc. are partitioned in the partitioned regions. Form. Then, the semiconductor wafer is cut along the streets to divide the region in which the device is formed to manufacture individual semiconductor chips. In addition, optical device wafers with gallium nitride compound semiconductors laminated on the surface of a sapphire substrate are also divided into individual optical devices such as light emitting diodes and laser diodes by cutting along the streets, and are widely used in electrical equipment. ing. The wafer to be divided in this manner is polished to a predetermined thickness by polishing the back surface by a polishing device before cutting along the street.

As described above, a polishing apparatus for polishing the back surface of a wafer includes a wafer holding means for holding a wafer, a polishing means for polishing a wafer held by the wafer holding means, and a wafer polished by the polishing means. Conveying means for conveying from the wafer holding means. (For example, refer to Patent Document 1.)
JP 2006-75929 A

  Since the polished wafer is thin, the conveying means that conveys the wafer from the wafer holding means conveys the entire surface of the wafer by suction holding the suction pad. However, if there is contamination on the suction pad, this contamination will adhere to the polished surface of the wafer, which is bad when performing subsequent steps such as attaching a bonding film for die bonding or applying a resist film for plasma dicing. There is a problem of affecting. In this way, the trouble caused by the contamination adhering to the suction pad of the conveying means adhering to the surface of the wafer occurs not only in the polishing apparatus but also in other processing apparatuses that process the wafer.

  The present invention has been made in view of the above-mentioned facts, and a main technical problem thereof is to provide a wafer processing apparatus that can transport a wafer without contacting the wafer processing surface when the wafer is transported from the wafer holding means. There is to do.

In order to solve the above main technical problem, according to the present invention, a wafer holding means for holding a wafer, a processing means for processing a wafer held by the wafer holding means, and a wafer processed by the processing means In a wafer processing apparatus comprising a conveying means for conveying from a wafer holding means,
The wafer holding means includes a wafer holding plate having a holding surface for holding the wafer and a held surface surrounding the holding surface, and a support base having a support surface for detachably supporting the wafer holding plate. Become
The support base includes a first suction passage and a second suction passage communicating with the first suction means and opening in the support surface;
The wafer holding plate communicates with the first suction passage of the support base with the first suction passage, the suction chamber in which the first communication passage opens, the suction chamber, and the holding surface. A plurality of suction holes that open, a second communication passage that communicates with the suction chamber and opens to the outer peripheral surface, and is disposed in the first communication passage and the second communication passage, respectively, from the suction chamber side. A first check valve and a second check valve that allow only the outflow of air,
The transport means comprises a plate holding member that holds the wafer holding plate, and an operating arm that supports the plate holding member,
The plate holding member includes a plurality of suction holes for sucking and holding the held surface of the wafer holding plate , and a suction passage for communicating the plurality of suction holes and the second suction means .
A wafer processing apparatus is provided.

In the wafer processing apparatus according to the present invention, in a state where the wafer is sucked and held on the holding surface of the wafer holding plate constituting the wafer holding means, the held surface surrounding the holding surface is provided on the plate holding member constituting the conveying means. Since the suction is held by the negative pressure acting on the plurality of suction holes, the plate holding member is not in contact with the processed surface of the wafer held on the holding surface of the wafer holding plate, so that it adheres to the plate holding member. Contamination does not adhere to the processed surface of the wafer. Accordingly, it is possible to prevent problems in the subsequent process caused by contamination on the processed surface of the wafer.

Preferred embodiments of a wafer processing apparatus constructed according to the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a perspective view of a polishing apparatus as a wafer processing apparatus constructed according to the present invention. The polishing apparatus shown in FIG. 1 includes an apparatus housing denoted as a whole by 2. This device housing 2 has a rectangular parallelepiped main portion 21 that extends long and an upright wall 22 that is provided at the rear end portion (upper right end in FIG. 1) of the main portion 21 and extends substantially vertically upward. ing. A pair of guide rails 221 and 221 extending in the vertical direction are provided on the front surface of the upright wall 22. The pair of guide rails 221 and 221 is mounted with a polishing unit 3 as a polishing means so as to be movable in the vertical direction.

  The polishing unit 3 includes a moving base 31 and a spindle unit 32 attached to the moving base 31. The movable base 31 is provided with a pair of legs 311 and 311 extending in the vertical direction on both sides of the rear surface. The pair of legs 311 and 311 is slidably engaged with the pair of guide rails 221 and 221. Guided grooves 312 and 312 are formed. As described above, a support portion 313 protruding forward is provided on the front surface of the movable base 31 slidably mounted on the pair of guide rails 221 and 221 provided on the upright wall 22. The spindle unit 32 is attached to the support portion 313.

  The spindle unit 32 includes a spindle housing 321 mounted on the support portion 313, a rotary spindle 322 rotatably disposed on the spindle housing 321, and a servo motor as a drive source for rotationally driving the rotary spindle 322. 323. A rotary spindle 322 rotatably supported by the spindle housing 321 has one end portion (lower end portion in FIG. 1) protruding from the lower end of the spindle housing 321 and a wheel mount at one end (lower end in FIG. 1). 324 is provided. Then, the polishing wheel 33 is attached to the lower surface of the wheel mount 324. The polishing wheel 33 includes an annular base 331 and a polishing grindstone 332 attached to the lower surface of the annular base 331, and the annular base 331 is attached to the lower surface of the wheel mount 324 with fastening bolts 34. It has been.

  The polishing apparatus in the illustrated embodiment includes a polishing unit feed mechanism 4 that moves the polishing unit 3 in the vertical direction (direction perpendicular to a holding surface of a chuck table described later) along the pair of guide rails 221 and 221. It has. The polishing unit feed mechanism 4 includes a male screw rod 41 disposed on the front side of the upright wall 22 and extending substantially vertically. The male screw rod 41 is rotatably supported by bearing members 42 and 43 whose upper end and lower end are attached to the upright wall 22. The upper bearing member 42 is provided with a pulse motor 44 as a drive source for rotationally driving the male screw rod 41, and the output shaft of the pulse motor 44 is connected to the male screw rod 41 by transmission. A connecting portion (not shown) that protrudes rearward from the center portion in the width direction is also formed on the rear surface of the movable base 31, and a through female screw hole (not shown) that extends in the vertical direction is formed in this connecting portion. The male screw rod 41 is screwed into the female screw hole. Therefore, when the pulse motor 44 rotates in the forward direction, the moving base 31, that is, the polishing unit 3 is lowered or moved forward, and when the pulse motor 44 rotates in the reverse direction, the moving base 31, that is, the polishing unit 3 is raised or moved backward.

  A wafer holding mechanism 5 is disposed in the main portion 21 of the housing 2. The wafer holding mechanism 5 includes a wafer holding unit 6 that holds a wafer as a workpiece, a cover member 51 that covers the periphery of the wafer holding unit 6, and a bellows unit 52 that is disposed before and after the cover member 51, and 53. The wafer holding means 6 is moved between a workpiece placing area 6a shown in FIG. 1 and a polishing area 6b facing the polishing wheel 33 constituting the spindle unit 32 by a moving means (not shown). The bellows means 52 and 53 can be formed from any suitable material such as campus cloth. The front end of the bellows means 52 is fixed to the front wall of the main portion 21, and the rear end is fixed to the front end surface of the cover member 51. The front end of the bellows means 53 is fixed to the rear end surface of the cover member 51, and the rear end is fixed to the front surface of the upright wall 22 of the apparatus housing 2. When the wafer holding means 6 is moved in the direction indicated by the arrow 6c, the bellows means 52 is expanded and the bellows 53 is contracted. When the wafer holding means 6 is moved in the direction indicated by the arrow 6d, the bellows means 52 is expanded. Is contracted, and the bellows means 53 is extended.

Next, the wafer holding means 6 will be described with reference to FIG.
The wafer holding means 6 shown in FIG. 2 includes a support base 7 having a support surface 71 on the upper surface, and a wafer holding plate 8 that is detachably supported on the support surface 71 of the support base 7. It can be rotated by a rotation driving means (not shown). The support base 7 is formed in a cylindrical shape by a metal material such as stainless steel, and has a first suction passage 72 that opens at the center of the support surface 71 and a phase difference of 90 degrees at the outer periphery of the support surface 71. A plurality of second suction passages 73 are provided. The first suction passage 72 and the second suction passage 73 are in communication with the first suction means 60. The first suction means 60 includes a suction source 61, and first electromagnetics disposed in pipes 62 and 63 that communicate the suction source 61 with the first suction passage 72 and the second suction passage 73, respectively. An on-off valve 64 and a second electromagnetic on-off valve 65 are provided. The first electromagnetic on-off valve 64 and the second electromagnetic on-off valve 65 are closed when they are de-energized (OFF), and are opened when energized (ON). Therefore, when the first electromagnetic on-off valve 64 and the second electromagnetic on-off valve 65 are energized (ON), negative pressure acts on the first suction passage 72 and the second suction passage 73.

  The wafer holding plate 8 includes a holding substrate 81 formed in a disk shape by a metal material such as stainless steel, and a suction chuck 82 disposed on the upper surface of the holding substrate 81. A circular fitting recess is provided on the upper surface of the holding substrate 81 to form a suction chamber 811. The fitting recess is provided with an annular mounting shelf 812 on which the suction chuck 82 is mounted on the outer periphery of the bottom surface. The holding substrate 81 formed in this manner is provided with a first communication path 813 that opens to the suction chamber 811 and opens to the lower surface at the lower part of the center. The first communication path 813 communicates with a first suction path 72 provided in the support base 7 when the wafer holding plate 8 is placed on the support surface 71 of the support base 7. . A first check valve 83 including a ball valve 831 and a coil spring 832 is disposed in the first communication path 813. The first check valve 83 is configured to allow only the outflow of air from the suction chamber 811 side and restrict the inflow of air to the suction chamber 811 side. In addition, the holding substrate 81 is provided with a second communication path 814 that opens to the suction chamber 811 and opens to the outer peripheral surface at the outer peripheral portion. A second check valve 84 composed of a ball valve 841 and a coil spring 842 is disposed in the second communication path 814. Like the first check valve 83, the second check valve 84 allows only the outflow of air from the suction chamber 811 side, and restricts the inflow of air to the suction chamber 811 side. Has been.

  In the illustrated embodiment, the suction chuck 82 is formed in a circular shape by a porous member such as porous ceramics. Therefore, the suction chuck 82 includes innumerable suction holes that communicate with the suction chamber 811 and open on the upper surface. The suction chuck 82 configured as described above is placed on an annular mounting shelf 812 formed on the holding substrate 81, and the upper surface functions as a holding surface 820 for holding the wafer. The annular upper surface of the holding substrate 81 surrounding the holding surface 821 functions as the held surface 810.

  In the wafer holding plate 8 configured as described above, the holding substrate 81 of the wafer holding plate 8 is placed on the upper surface 71 of the support base 7 as shown in FIG. When the first electromagnetic on-off valve 64 and the second electromagnetic on-off valve 65 of the first suction means 60 are energized (ON), as described above, the first suction passage 72 and the second suction passage 73 are brought into contact with each other. Negative pressure acts. As a result, the outer peripheral portion of the lower surface of the holding substrate 81 of the wafer holding plate 8 facing the second suction passage 73 is sucked, and the wafer holding plate 8 is sucked and held on the upper surface 71 of the support base 7. On the other hand, the negative pressure acting on the first suction passage 72 acts on the first check valve 84 disposed in the first communication passage 814 provided in the wafer holding plate 8, and the ball valve 841 is coiled. The valve is sucked downward in FIG. 2 to open against the spring force of the spring 842. As a result, the negative pressure acting on the first suction passage 72 acts on the suction chamber 811 through the first communication passage 814 and further acts on the holding surface 820 via the numerous suction holes formed in the suction chuck 82. To do. Therefore, if the wafer is placed on the holding surface 820, the wafer is sucked and held on the holding surface 820.

  Referring back to FIG. 1, the description of the polishing apparatus in the illustrated embodiment will be described. The polishing device in the illustrated embodiment is a wafer that is a workpiece polished on the wafer holding plate 8 of the wafer holding means 6 and a transfer means for transferring the wafer holding plate 8. 9 is provided. The conveying means 9 includes a plate holding member 91 for sucking and holding the wafer holding plate 8, an operating arm 92 for supporting the plate holding member 91, and a supporting means 93 for supporting the operating arm 92. It is arranged on the side of the device housing 2.

The plate holding member 91 which comprises the conveyance means 9 is demonstrated with reference to FIG.
A plate holding member 91 shown in FIG. 3 includes a circular recess 911 into which the wafer holding plate 8 is fitted. The circular recess 911 is formed to have an inner diameter slightly larger than the outer diameter of the wafer holding plate 8, and the outer peripheral portion of the bottom surface corresponds to the annular held surface 810 of the holding substrate 81 of the wafer holding plate 8. A holding shelf 912 having a width is provided. The thickness of the holding shelf 912 is set to be larger than a value obtained by adding the thickness of a wafer, which will be described later, and the thickness of the protective tape. The plate holding member 91 is formed with a plurality of suction holes 913 that open on the surface of the holding shelf 912. Further, the plate holding member 91 is formed with a first suction passage 914 communicating with the plurality of suction holes 913 and a second suction passage 915 opening on the inner peripheral surface of the circular recess 911. It is desirable that a seal 916 surrounding the opening of the second suction passage 916 be disposed on the inner peripheral surface of the recess 911 in which the second suction passage 915 opens.

  As described above, the first suction passage 914 and the second suction passage 915 formed in the plate holding member 91 are communicated with the second suction means 90 via the communication passage 921 provided in the operating arm 92. Yes. The second suction means 90 is provided with a suction source 901 and an electromagnetic on-off valve 903 disposed in a pipe 902 communicating with the suction source 901 and the communication path 921. This electromagnetic on-off valve 903 is closed when de-energized (OFF), and is opened when energized (ON). Therefore, when the electromagnetic on-off valve 64 is energized (ON), negative pressure acts on the first suction passage 914 and the second suction passage 915 via the pipe 902 and the communication passage 921.

  Returning to FIG. 1, the description will be continued. The supporting means 93 constituting the conveying means 9 is composed of an air cylinder, a pulse motor and the like, and moves the operating arm 92 in the vertical direction as indicated by the arrow 9a, and at the arrow 9b. It is comprised so that it may turn as shown.

The polishing apparatus in the illustrated embodiment is configured as described above, and the operation thereof will be described below.
As shown in FIG. 1, a semiconductor wafer W as a workpiece is placed on a suction chuck 82 that constitutes a wafer holding plate 8 of the wafer holding means 6 positioned in the workpiece placement area 6a of the polishing apparatus. . A protective tape T is attached to the surface on which the semiconductor wafer W device is formed, and the protective tape T side is placed on the suction chuck 82 of the wafer holding plate 8.

  When the semiconductor wafer W is placed on the suction chuck 82 of the wafer holding plate 8 in this way, the first electromagnetic opening / closing valve 64 and the second electromagnetic valve 64 of the first suction means 60 as shown in FIG. The on-off valve 65 is energized (ON), and the first electromagnetic on-off valve 64 and the second electromagnetic on-off valve 65 are opened to form the support base 7 constituting the wafer holding means 6 as described above. Negative pressure is applied to the first suction passage 72 and the second suction passage 73. As a result, the outer peripheral portion of the lower surface of the holding substrate 81 of the wafer holding plate 8 facing the second suction passage 73 is sucked, and the wafer holding plate 8 is sucked and held on the upper surface 71 of the support base 7. The second electromagnetic opening / closing valve 65 is energized (ON) before the semiconductor wafer W is placed on the suction chuck 82 of the wafer holding plate 8, and is formed on the support base 7 constituting the wafer holding means 6. It is desirable to apply a negative pressure to the second suction passage 73 so that the wafer holding plate 8 is sucked and held on the upper surface 71 of the support base 7. On the other hand, the negative pressure acting on the first suction passage 72 acts on the first check valve 83 disposed in the first communication passage 813 provided in the wafer holding plate 8, and the ball valve 831 is coiled. The valve 8 is opened by suctioning downward in FIG. 4 against the spring force of the spring 832. As a result, the negative pressure acting on the first suction passage 72 acts on the suction chamber 811 through the first communication passage 813, and further acts on the holding surface 820 through the numerous suction holes formed in the suction chuck 82. Therefore, the semiconductor wafer W placed on the suction chuck 82 is sucked and held on the holding surface 820 of the suction chuck 82. When the pressure in the suction chamber 811 approaches the pressure in the first suction passage 72, the ball valve 831 is closed by the spring force of the coil spring 832.

  As described above, the wafer holding plate 8 is sucked and held on the support base 7 constituting the wafer holding means 6, and the semiconductor wafer W is sucked and held on the holding surface 821 of the suction chuck 82 constituting the wafer holding plate 8. Then, the moving means (not shown) is operated to move the wafer holding means 6 in the direction indicated by the arrow 6c and to be positioned in the polishing zone 6b. At this time, the polishing grindstone 332 constituting the polishing wheel 33 of the polishing unit 3 is positioned so as to pass through the rotation center of the wafer holding means 6, that is, the center of the semiconductor wafer W.

  When the polishing wheel 332 constituting the polishing wheel 33 and the semiconductor wafer W held by the wafer holding means 6 are set in a predetermined positional relationship, the wafer holding means 6 is rotated in a predetermined direction, for example, at a rotation speed of 300 rpm. And the grinding wheel 33 rotates in a predetermined direction at a rotational speed of, for example, 6000 rpm. Then, the polishing wheel 33 is lowered to press the plurality of polishing wheels 332 against the back surface (surface to be polished), which is the upper surface of the semiconductor wafer W, with a predetermined pressure (polishing step). As a result, the surface to be polished of the semiconductor wafer W is polished over the entire surface. When the semiconductor wafer W is polished to a predetermined thickness by performing this polishing step, the polishing wheel 33 is raised to stop the rotation and the rotation of the wafer holding means 6 is stopped. Then, the moving means (not shown) is operated to position the wafer holding means 6 in the workpiece placement area 6a.

  When the wafer holding means 6 holding the semiconductor wafer W polished to a predetermined thickness in this way is positioned in the workpiece placement area 6a, the support means 93 of the conveying means 9 is operated. The plate holding member 91 is moved to a position above the wafer holding means 6 and lowered. As a result, as shown in FIG. 5, the concave portion 911 of the plate holding member 91 is fitted into the wafer holding plate 8 constituting the wafer holding means 6. As a result, the holding shelf 912 formed in the concave portion 911 of the plate holding member 91 is placed on the annular held surface 810 of the holding substrate 81 of the wafer holding plate 8. Since the thickness of the holding shelf 912 is set larger than the value obtained by adding the thickness of the semiconductor wafer W and the thickness of the protective tape T as described above, the bottom surface of the recess 911 is held by the plate holding member 91. Do not touch the upper surface (polished surface) of the semiconductor wafer W. Therefore, the contamination adhering to the plate holding member 91 does not adhere to the surface of the wafer. Further, the second suction passage 916 provided in the plate holding member 91 is positioned at a position facing the second communication passage 814 formed in the holding substrate 81 of the wafer holding plate 8.

  As shown in FIG. 5, when the recess 911 of the plate holding member 91 is fitted to the wafer holding plate 8 of the wafer holding means 6, the electromagnetic opening / closing valve 903 of the second suction means 90 constituting the conveying means 9 is energized. The first suction passage 914 and the second suction passage formed in the plate holding member 91 via the communication passage 921 formed in the pipe 902 and the operating arm 92 by opening the electromagnetic on-off valve 903. A negative pressure is applied to 916. As a result, the negative pressure acting on the first suction passage 914 acts on the plurality of suction holes 913 to suck and hold the annular held surface 810 of the holding substrate 81 of the wafer holding plate 8. On the other hand, the negative pressure acting on the second suction passage 916 acts on the second check valve 84 disposed in the second communication passage 814 formed on the holding substrate 81 of the wafer holding plate 8, The ball valve 841 constituting the second check valve 84 is suctioned and opened to the left in FIG. 5 against the spring force of the coil spring 842. As a result, the negative pressure acting on the second communication path 814 acts on the suction chamber 811 through the third communication path 814, and further acts on the holding surface 821 via the numerous suction holes formed in the suction chuck 82. Therefore, the semiconductor wafer W placed on the suction chuck 82 is maintained in a state of being sucked and held on the holding surface 821 of the suction chuck 82. Next, the first electromagnetic on-off valve 64 and the second electromagnetic on-off valve 65 of the first suction means 60 are de-energized (OFF). As a result, the negative pressure acting on the second suction passage 73 formed in the support base 7 is released, the suction holding of the wafer holding plate 8 is released, and the first suction passage 72 is acting. Negative pressure is released.

  As described above, if the wafer holding plate 8 (which holds the polished semiconductor wafer W by suction) is sucked and held by the plate holding member 91 of the transport means 9, the support means 93 is operated to operate the support means 93 as shown in FIG. The plate holding member 91 is moved upward as shown in FIG. As a result, the wafer holding plate 8 sucked and held by the plate holding member 91 is detached from the support base 7 in a state where the polished semiconductor wafer W is sucked and held. Then, the transport means 9 operates the support means 93 to transport the wafer holding plate 8 holding the polished semiconductor wafer W by suction to the next process. As described above, the polished semiconductor wafer W transported while being sucked and held by the wafer holding plate 8 is not in contact with the plate holding member 91 as described above, and is attached to the plate holding member 91. Since the contaminated material does not adhere to the polished surface of the semiconductor wafer W, it is possible to prevent problems in the subsequent processes caused by the contaminated material from adhering to the polished surface.

As mentioned above, although this invention was demonstrated based on embodiment of illustration, this invention is not limited only to embodiment, A various deformation | transformation is possible in the range of the meaning of this invention. For example, in the illustrated embodiment, the example in which the wafer holding plate 8 is sucked and held by the plate holding member 91 is shown, but the plate holding member 91 may be configured to hold the wafer holding plate 8.
In the illustrated embodiment, the present invention is applied to a polishing apparatus. However, the present invention is not limited to the polishing apparatus, but can be applied to other processing apparatuses that process a wafer.

The perspective view of the polish device as a processing device of a wafer constituted according to the present invention. Sectional drawing of the wafer holding means which comprises the grinding | polishing apparatus shown in FIG. FIG. 2 is a cross-sectional view of a main part of a transfer device constituting the polishing apparatus shown in FIG. 1. Sectional drawing which shows the state which attracted and hold | maintained the wafer as a workpiece on the wafer holding plate of the wafer holding means which comprises the grinding | polishing apparatus shown in FIG. Sectional drawing which shows the state which attracted and held the wafer holding plate of the wafer holding means which comprises the grinding | polishing apparatus shown in FIG. 1 to the plate holding member of a conveyance means. Sectional drawing which shows the state which moved the plate holding member upwards in the state which attracted and held the wafer holding plate of the wafer holding means.

Explanation of symbols

2: Device housing 3: Polishing unit 31: Moving base 32: Spindle unit 33: Polishing wheel 4: Polishing unit feeding mechanism 5: Wafer holding mechanism 51: Cover member 52, 53: Bellows means 6: Wafer holding means 60: No. 1 suction means 61: suction source 64: first electromagnetic on-off valve 65: second electromagnetic on-off valve 7: support base 71: support surface 72: first suction passage 73: second suction passage 8: wafer holding Plate 81: Holding substrate 810: Surface to be held 811: Suction chamber 82: Suction chuck 83: First check valve 84: Second check valve 9: Transport means 90: Second suction means 901: Suction source 903 : Electromagnetic on-off valve 91: Plate holding member 911: Circular recess 912: Holding shelf 913: Multiple suction holes 914: First suction passage 915: Second suction passage 92: Actuating door 93: Support means

Claims (1)

A wafer comprising: a wafer holding means for holding a wafer; a processing means for processing a wafer held by the wafer holding means; and a transfer means for transferring the wafer processed by the processing means from the wafer holding means. In processing equipment,
The wafer holding means includes a wafer holding plate having a holding surface for holding the wafer and a held surface surrounding the holding surface, and a support base having a support surface for detachably supporting the wafer holding plate. Become
The support base includes a first suction passage and a second suction passage communicating with the first suction means and opening in the support surface;
The wafer holding plate communicates with the first suction passage of the support base with the first suction passage, the suction chamber in which the first communication passage opens, the suction chamber, and the holding surface. A plurality of suction holes that open, a second communication passage that communicates with the suction chamber and opens to the outer peripheral surface, and is disposed in the first communication passage and the second communication passage, respectively, from the suction chamber side. A first check valve and a second check valve that allow only the outflow of air,
The transport means comprises a plate holding member that holds the wafer holding plate, and an operating arm that supports the plate holding member,
The plate holding member includes a plurality of suction holes for sucking and holding the held surface of the wafer holding plate , and a suction passage for communicating the plurality of suction holes and the second suction means .
A wafer processing apparatus characterized by that.

Images