JP2012119464A - Device and method for holding wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a method for holding a wafer, capable of holding a wafer irrespective of a warp state of the wafer.SOLUTION: The wafer holding device holds a wafer 1 having a warp by vacuum sucking. The wafer holding device includes: a suction chuck 11 for holding the wafer 1 by vacuum sucking; a correction portion 21 for correcting the warp of the wafer 1 to bring the wafer 1 having the warp close to a flat state; and a suction guard 31 for holding the outer circumference portion of the wafer 1. The suction guard 31 holds the wafer 1 above the correction portion 21. Further, the suction guard 31 descends in a state of supporting the wafer 1, so as to press the wafer 1 onto the correction portion 21. By this, the wafer 1 comes to be close to the flat state. In this state, the suction chuck 11 positioned below the correction portion 21 is ascended. The suction chuck 11 ascends in a suction chuck opening portion 23 of the correction portion 21, and sucks a portion of the wafer 1 exposed on the suction chuck opening portion 23.

Description

  The present invention relates to a wafer holding apparatus and a wafer holding method.

  In a processing apparatus that performs various processing on a wafer made of silicon (Si), a single-wafer processing apparatus that performs processing on each wafer is often used. In such a processing apparatus or a wafer transport mechanism for transporting a wafer to the processing apparatus, the wafer is subjected to various processing or wafers after being held by vacuum-sucking a portion of the center or outer periphery of the wafer. It is being transported.

  When the wafer is transferred by the wafer transfer mechanism, a large external force is not applied to the wafer. For this reason, from a configuration in which a part of the outer peripheral portion of the wafer is sucked and held, a configuration having a plate-like holding portion having only a guide that prevents the wafer from being displaced in the horizontal direction without sucking the wafer A wafer transfer mechanism having a low holding force has also been proposed.

  On the other hand, in a processing apparatus that performs a process of spin-coating a resist on a wafer, a large centrifugal force is generated on the wafer when the wafer is rotated. In such a processing apparatus, it is necessary to hold the wafer with a higher holding force than the above-described wafer transfer mechanism. In this case, for example, a wafer holding device including a jig (hereinafter referred to as a suction chuck) that holds the wafer by vacuum suction is used.

  FIG. 6 is an explanatory view showing a part of a conventional wafer holding apparatus. In FIG. 6, in order to clarify the contact surface between the suction chuck and the wafer, the portion of the suction chuck is shown enlarged (hereinafter, the same applies to FIG. 7). The wafer holding apparatus shown in FIG. 6 includes a suction chuck 111 that vacuum-sucks the wafer 101. A plurality of grooves (hereinafter referred to as suction grooves) 112 that can be evacuated are provided on the surface of the suction chuck 111 that holds the wafer 101 (hereinafter referred to as a wafer holding surface).

  Inside the support shaft 113 of the suction chuck 111, a vent hole 114 that can be evacuated is provided. The ventilation hole 114 is connected to the suction groove 112. The ventilation hole 114 is connected to a vacuum generation source (not shown). In such a wafer holding apparatus, the wafer 101 is placed on the wafer holding surface of the suction chuck 111, the ventilation hole 114 is evacuated by a vacuum generation source, and the wafer 101 is vacuum-sucked in the suction groove 112.

  As a wafer holding device that vacuum-sucks a wafer, the wafer holding surface for sucking and fixing the wafer is processed into a shape that matches the warp of the semiconductor wafer to absorb the warp of the semiconductor wafer. There has been proposed a device that can adsorb and fix a semiconductor wafer without correcting the above (for example, see Patent Document 1 below).

JP 2001-210704 A

  However, as a result of extensive research by the inventor, it has been found that the following problems occur. When a conventional wafer holding device (see FIG. 6) is used to place a wafer 101 warped in a concave shape on the front surface side on the wafer holding surface of the suction chuck 111 with the front surface facing upward, The wafer 101 is adsorbed only in the adsorption groove 112 provided in the center of the wafer holding surface of the chuck 111. That is, the wafer 101 does not contact the suction groove 112 provided on the outer peripheral portion of the wafer holding surface of the suction chuck 111. For this reason, a location (leak location) 121 where gas flows from the suction groove 112 is formed on the outer peripheral portion of the wafer holding surface of the suction chuck 111.

  Such a problem also occurs when a wafer warped in a convex shape on the front side is placed on the wafer holding surface of the suction chuck 111 with the front side facing up. FIG. 7 is an explanatory view showing a part of a conventional wafer holding apparatus. As shown in FIG. 7, the wafer 102 warped in a convex shape on the front surface side does not contact almost all the suction grooves 112 on the wafer holding surface of the suction chuck 111. For this reason, a leak portion 122 is formed on almost the entire wafer holding surface of the suction chuck 111.

  That is, the wafers 101 and 102 are warped to such an extent that they cannot be sucked by a part or the whole of the wafer holding surface of the suction chuck 111, and warpage cannot be corrected by the vacuum suction force of the suction chuck 111. When the wafers 101 and 102 are warped, the leak portions 121 and 122 are formed as described above, which causes a problem that the wafers 101 and 102 cannot be held by vacuum suction.

  Specifically, when the warpage of the wafers 101 and 102 is about 3 mm or less, the warpage of the wafer can be corrected by the vacuum suction force by the suction chuck 111, and the warpage of the wafers 101 and 102 is about 5 mm or less. It is known that the wafer can be vacuum-sucked and held on the suction chuck 111.

  That is, when the warpage of the wafers 101 and 102 exceeds 5 mm, the wafers 101 and 102 cannot be held by vacuum suction on the suction chuck 111. Thus, in the conventional wafer holding device (see FIGS. 6 and 7), when the warpage of the wafers 101 and 102 exceeds the range of the warp that can be sucked by the wafer holding device, the wafers 101 and 102 are vacuum-sucked. I can't hold it.

  An object of the present invention is to provide a wafer holding apparatus and a wafer holding method that can hold a wafer regardless of the state of warping of the wafer, in order to solve the above-described problems caused by the prior art.

  In order to solve the above-described problems and achieve the object of the present invention, a wafer holding device according to the invention of claim 1 is a wafer holding device that sucks and holds a wafer, wherein the warped wafer is A holding means for holding the outer peripheral part; a correcting means for bringing the wafer into a flat state; and an adsorbing means for adsorbing the central part of the wafer, and relatively moving the holding means and the correcting means. Then, the center of the wafer is sucked by the sucking means.

  According to a second aspect of the present invention, there is provided the wafer holding apparatus according to the first aspect of the invention, wherein the holding means sucks the wafer while supporting the outer peripheral portion of the warped wafer. The outer periphery of the wafer is held.

  According to a third aspect of the present invention, there is provided the wafer holding apparatus according to the first or second aspect, wherein the holding means holds the wafer above the straightening means, and then the wafer becomes the straightening means. It is characterized by descending until contact.

  According to a fourth aspect of the present invention, there is provided the wafer holding apparatus according to the third aspect, wherein the holding means holds the wafer above the correction means and then lowers the wafer while sucking it. It is characterized by.

  According to a fifth aspect of the present invention, the wafer holding apparatus according to the third or fourth aspect is characterized in that a portion of the correcting means that contacts the wafer is flat.

  A wafer holding apparatus according to a sixth aspect of the invention is characterized in that, in the invention according to any one of the first to fifth aspects, the correction means has an opening through which the suction means passes. .

  According to a seventh aspect of the present invention, there is provided the wafer holding device according to the sixth aspect, wherein the suction unit is configured to expose a portion of the wafer that is in contact with the correction unit and exposed to the opening of the correction unit. It is characterized by adsorbing.

  A wafer holding apparatus according to an eighth aspect of the present invention is the wafer holding apparatus according to any one of the second to seventh aspects, wherein the correction means is an air exhausted when the holding means sucks the wafer. It has the suction pipe which passes.

  In order to solve the above-mentioned problems and achieve the object of the present invention, a wafer holding method according to claim 9 is a wafer holding method for adsorbing and holding a wafer, wherein the warp is generated. A placing step of placing the wafer at a position facing the flat surface of the member having a flat surface; a holding step of holding the outer peripheral portion of the wafer after the placing step; and the holding step. And a correction step of bringing the wafer having the outer periphery held into contact with the flat surface, and an adsorption step of sucking the central portion of the wafer in contact with the flat surface.

  According to a tenth aspect of the present invention, in the method for holding a wafer according to the ninth aspect, the wafer is placed above the flat surface in the placing step, and the wafer is placed in the correcting step. Is lowered and brought into contact with the flat surface.

  The wafer holding method according to the invention of claim 11 is characterized in that, in the invention of claim 9 or 10, the wafer is sucked in a state in which the outer peripheral portion of the warped wafer is supported. .

  A wafer holding method according to a twelfth aspect of the invention is characterized in that, in the invention according to any one of the ninth to eleventh aspects, in the correction step, the wafer is lowered while being sucked.

  A wafer holding method according to a thirteenth aspect of the present invention is the wafer holding method according to any one of the ninth to twelfth aspects, wherein, in the adsorption step, a central portion of a surface of the wafer that is in contact with the flat surface. It is characterized by adsorbing.

  A wafer holding method according to a fourteenth aspect of the present invention is the wafer holding method according to any one of the ninth to thirteenth aspects, wherein, in the adsorption step, the opening of the member having the flat surface of the wafer. It is characterized by adsorbing a portion exposed to the surface.

  According to the first to ninth aspects, the holding means for sucking the wafer and holding the outer peripheral portion of the wafer, the correcting means for bringing the wafer held by the holding means close to a flat state, and the holding means and the correcting means. Suction means for sucking a wafer brought close to a flat state. Since the suction means sucks the wafer after the wafer is brought close to a flat state, there is no possibility of a leak (see FIGS. 6 and 7) on the outer peripheral portion or the entire surface of the wafer holding surface of the suction means. Therefore, the warped wafer can be sucked with a stronger suction force than before.

  The correction means is provided with an opening through which the suction means passes when the suction means rises (hereinafter referred to as an suction chuck opening). For this reason, the adsorption unit can adsorb the wafer held in the correction unit and the holding unit while being held in the correction unit and the holding unit. For this reason, when the suction means sucks the wafer, the wafer brought close to the flat state does not return to the original warped state. Thereby, the suction means can suck the wafer brought close to a flat state. Therefore, the warped wafer can be reliably adsorbed by the adsorbing means.

  According to the ninth to fourteenth aspects described above, the holding means is lowered while the wafer is held by the suction force, and is brought into contact with the flat surface of the correcting means (a member having a flat surface). For this reason, the wafer is brought into contact with the flat surface of the correcting means without being detached from the holding means. Thus, the warped wafer can be brought close to a flat state along the flat surface of the correcting means. Further, after the wafer is brought close to a flat state, it is adsorbed by the adsorbing means. For this reason, a leak location (see FIGS. 6 and 7) is not formed on the outer peripheral portion or the entire surface of the wafer holding surface of the suction means. Therefore, the warped wafer 1 can be adsorbed with a strong adsorbing force.

  According to the wafer holding device and the wafer holding method of the present invention, there is an effect that the wafer can be held regardless of the state of warping of the wafer.

It is explanatory drawing which shows the structure of the wafer holding | maintenance apparatus concerning embodiment. It is explanatory drawing shown about the wafer holding method concerning embodiment. It is explanatory drawing shown about the wafer holding method concerning embodiment. It is explanatory drawing shown about the wafer holding method concerning embodiment. It is explanatory drawing shown about the wafer holding method concerning embodiment. It is explanatory drawing which shows a part of conventional wafer holding device. It is explanatory drawing which shows a part of conventional wafer holding device.

  Exemplary embodiments of a wafer holding apparatus and a wafer holding method according to the present invention will be explained below in detail with reference to the accompanying drawings. Note that, in the following description of the embodiments and the accompanying drawings, the same reference numerals are given to the same components, and duplicate descriptions are omitted.

(Embodiment)
FIG. 1 is an explanatory diagram illustrating a configuration of a wafer holding device according to an embodiment. As shown in FIG. 1, the wafer holding apparatus according to the embodiment holds the wafer 1 by vacuum suction. Here, the case where the back surface of the wafer 1 warped in a concave shape on the front surface side is held by vacuum suction will be described.

  As shown in FIG. 1, the wafer holding device has a jig (suction chuck) 11 that holds the wafer 1 by vacuum suction and corrects the warpage of the wafer 1 so that the warped wafer 1 is flat. And a jig (holding portion: hereinafter referred to as a suction guard) 31 for sucking the wafer 1 while supporting the outer peripheral portion of the wafer 1 and holding the outer peripheral portion of the wafer 1. And comprising. The wafer holding device sucks the central portion of the wafer by the suction chuck 11 after relatively moving the suction guard 31 and the correction unit 21. The operation of each component of the wafer holding device will be described later.

  The suction chuck 11 is provided inside the suction guard 31. Further, the suction chuck 11 is provided so as to be movable up and down by a support shaft 13. The suction chuck 11 has, for example, a circular planar shape. The diameter of the suction chuck 11 is smaller than the diameter of the wafer 1, for example. A plurality of grooves (suction grooves) 12 that can be evacuated are provided on the surface (wafer holding surface) of the suction chuck 11 that holds the wafer 1.

  Inside the support shaft 13 of the suction chuck 11, a vent hole 14 that can be evacuated is provided. The ventilation holes 14 are connected to all the suction grooves 12. The ventilation hole 14 is connected to a vacuum generation source (not shown) such as a vacuum pump. The suction groove 12 and the vent hole 14 are evacuated by the vacuum generation source.

  The correction unit 21 is provided above the suction chuck 11 inside the suction guard 31. Further, the correction unit 21 is provided so as to be movable up and down by a support shaft 22. The correction unit 21 contacts the wafer 1 held by the suction guard 31 and brings the wafer 1 close to a flat state. Specifically, the surface of the correction unit 21 that contacts the wafer 1 is flat. The wafer 1 held by the suction guard 31 is brought into contact with and pressed against this flat surface, whereby the warpage of the wafer 1 is corrected.

  The support shaft 22 of the correction unit 21 surrounds the suction chuck 11, for example. Further, the correction unit 21 is provided horizontally on the wafer holding surface of the suction chuck 11. The correction part 21 has a plate-like cross-sectional shape. An opening (adsorption chuck opening) 23 through which the suction chuck 11 passes when the suction chuck 11 is raised is provided at a portion of the correction unit 21 that faces the suction chuck 11. The suction chuck opening 23 is provided, for example, at the center of the correction unit 21.

  The inner diameter of the suction chuck opening 23 may be any size as long as the suction chuck 11 can pass through. For example, the inner diameter of the suction chuck opening 23 has a circular planar shape having an inner diameter slightly larger than the inner diameter of the suction chuck 11. As a result, when the suction chuck 11 is raised, the portion of the wafer 1 that is in contact with the correction unit 21 and exposed to the suction chuck opening 23 of the correction unit 21 is suctioned to the suction chuck 11. That is, the suction chuck opening 23 is open to such an extent that the central portion of the wafer 1 is exposed.

  Further, a plurality of ventilation holes (hereinafter referred to as suction pipes) through which the air exhausted when the wafer 1 is sucked by the suction guard 31 and the inside of the suction guard 31 is exhausted are passed through the correction unit 21. 24 is provided. The suction tube 24 is provided apart from the suction chuck opening 23. The suction tube 24 has a circumferential planar shape surrounding the suction chuck opening 23. The suction tube 24 may have an arcuate planar shape that selectively surrounds the suction chuck opening 23.

  The suction guard 31 is provided so as to be movable up and down by a cylindrical support shaft 32. The suction guard 31 is composed of a main body portion having an opening on the top surface and a side wall and a bottom surface, and an exhaust port is provided on the bottom surface of the main body portion. The diameter of the opening 33 of the suction guard 31 is such that the outer periphery of the wafer 1 is just in contact. For example, the diameter of the opening 33 of the suction guard 31 may be approximately the same as the diameter of the planar shape of the wafer 1 that is warped. Here, the diameter of the planar shape of the wafer 1 in which the warpage has occurred is a diameter smaller than the diameter of the wafer 1 in a state in which no warpage has occurred by the amount of warpage.

  The suction guard 31 holds the outer periphery of the wafer 1 at the upper end of the side wall. Specifically, the suction guard 31 sucks the wafer 1 in a state where the outer periphery of the wafer 1 is supported after the wafer 1 is placed on the upper end of the side wall. As a result, a downward suction force acts on the wafer 1, and the outer peripheral end portion of the wafer 1 is held at the upper end of the side wall of the suction guard 31. That is, the suction guard 31 holds the outer peripheral portion of the wafer 1 such that the opening 33 is blocked by the wafer 1. As a result, the correction unit 21 is positioned between the wafer 1 and the suction chuck 21 inside the suction guard 31.

  Further, the suction guard 31 moves down while sucking the wafer 1 until it holds the wafer 1 above the correction unit 21 and then contacts the correction unit 21. As a result, the wafer 1 held by the suction guard 31 does not come off the suction guard 31 even after contacting the correction unit 21. The suction force applied to the wafer 1 by the suction guard 31 may be a suction force that does not detach from the suction guard 31 when the wafer 1 held by the suction guard 31 comes into contact with the correction unit 21.

  The support shaft 32 of the suction guard 31 is connected to the exhaust port of the suction guard 31. That is, the support shaft 32 of the suction guard 31 is provided on the bottom surface opposite to the opening 33 of the suction guard 31. An exhaust mechanism (not shown) is connected to the support shaft 32 of the suction guard 31. The inside of the main body of the suction guard 31 is exhausted through the support shaft 32 of the suction guard 31 by the exhaust mechanism. That is, the funnel-shaped suction guard 31 is configured by the suction guard 31 and the support shaft 32 of the suction guard 31.

  A step 34 may be provided in the opening 33 of the suction guard 31. The diameter of the opening 33 of the suction guard 31 including the stepped portion 34 has substantially the same dimension as the diameter when the warped wafer 1 approaches a flat state. By providing such a stepped portion 34, when the warped wafer 1 approaches a flat state, the portion of the suction guard 31 that holds the outer peripheral portion of the wafer 1 can be softened. Thereby, the wafer 1 can be stably held by the suction guard 31.

  Next, a wafer holding method using the wafer holding apparatus shown in FIG. 1 will be described. 2 to 5 are explanatory diagrams showing the wafer holding method according to the embodiment. First, as shown in FIG. 1, the wafer 1 having a concave warpage on the front surface side is placed on the opening 33 of the suction guard 31 with the front surface facing upward (placement step). ). Thus, the wafer 1 is placed at a position above the correction unit 21 and facing the flat surface of the correction unit 21. At this time, the correction unit 21 is located above the suction chuck 11. The wafer 1 may be in contact with the correction unit 21 or may be separated from the correction unit 21.

  Next, as shown in FIG. 2, the exhaust 30 inside the suction guard 31 is performed by an exhaust mechanism (not shown). The exhaust port of the suction guard 31 is provided on the bottom surface of the suction guard 31. For this reason, although the correction part 21 is located between the wafer 1 and the exhaust port, since the suction pipe 24 is provided in the correction part 21, the suction guard 31 is interposed via the suction pipe 24 of the correction part 21. The wafer 1 can be sucked. As a result, a downward suction force acts on the wafer 1, and the outer peripheral end portion of the wafer 1 is held at the upper end of the side wall of the suction guard 31. Thereby, the wafer 1 is fixed to the suction guard 31 (holding step).

  Next, the suction guard 31 is lowered while holding the wafer 1, and the wafer 1 is brought into contact with the correction unit 21. That is, the position of the suction guard 31 is moved from the first position 41 to the second position 42 (see FIG. 3). In FIG. 2, the code | symbol 40 has shown the moving direction of the suction guard 31 (same also in FIG. 4). The position of the suction guard 31 indicates the position of the upper end of the suction guard 31 (hereinafter, the same applies to the suction chuck 11 and the correction unit 21). Further, at the same time as the suction guard 31 is lowered, the exhaust 30 inside the suction guard 31 is exhausted by the exhaust mechanism.

  Thereby, as shown in FIG. 3, the back side of the wafer 1 held by the suction force in the opening 33 of the suction guard 31 comes into contact with the flat surface of the correction unit 21, and the wafer 1 is pressed against the correction unit 21. Therefore, the warpage of the wafer 1 is corrected along the flat surface of the correction unit 21 and the wafer 1 is brought close to a flat state. That is, the wafer 1 becomes flatter than the state before being placed on the suction guard 31 (correction process).

  In the correction step, it is preferable to correct the warpage of the wafer 1 so that the warpage of the wafer 1 becomes, for example, 1 mm or less that can be attracted by the suction chuck 11. Here, it suffices that only the portion of the wafer 1 that is sucked by the suction chuck 11 is flat enough to be sucked by the suction chuck 11.

  Next, the suction chuck 11 positioned below the third position 51 of the correction unit 21 is raised. The suction chuck 11 moves inside the suction chuck opening 23 of the correction unit 21, rises from the fourth position 61 to the third position 51 of the correction unit 21, and moves to the fifth position 62. . That is, the fifth position 62 of the suction chuck 11 is substantially the same as the third position 51 of the correction unit 21. In FIG. 3, reference numeral 60 indicates the moving direction of the suction chuck 11.

  As a result, as shown in FIG. 4, the suction chuck 11 comes into contact with a portion of the back surface of the wafer 1 exposed to the suction chuck opening 23 of the correction unit 21. Since the wafer 1 is approaching a flat state by the correction process, all the suction grooves 12 (see FIG. 1) of the suction chuck 11 are closed by the wafer 1.

  Next, a plurality of suction grooves 12 of the suction chuck 11 are evacuated by a vacuum generating means (not shown) through a ventilation hole 14 (see FIG. 1) provided in the support shaft 13 of the suction chuck 11. Thereby, the back surface of the wafer 1 is attracted to the suction groove 12 of the suction chuck 11 (suction process). As described above, since the wafer 1 is in contact with all the suction grooves 12 of the suction chuck 11, the wafer 1 is reliably sucked into all the suction grooves 12 of the suction chuck 11.

  Next, the suction guard 31 is lowered, and the position of the suction guard 31 is moved from the second position 42 to the sixth position 43 (see FIG. 5). At the same time, the correction unit 21 is lowered and the position of the correction unit 21 is moved from the third position 51 to the seventh position 52 (see FIG. 5). In FIG. 4, reference numeral 50 indicates the moving direction of the correction unit 21. As a result, the suction guard 31 and the correction unit 21 are separated from the wafer 1, and the wafer 1 is held only by the suction chuck 11. At this time, the suction chuck 11 sucks the wafer 1 held by the suction guard 31 and the correction unit 21.

  As described above, according to the wafer holding apparatus of the embodiment, the suction guard 31 that holds the outer peripheral portion of the wafer 1, and the correction unit 21 that brings the wafer 1 held by the suction guard 31 close to a flat state, A suction chuck 11 for sucking a wafer brought into a flat state by the suction guard 31 and the correction unit 21. Since the suction chuck 11 sucks the wafer 1 after the wafer 1 is brought close to a flat state, there is no possibility of a leak (see FIG. 6) on the outer periphery of the wafer holding surface of the suction chuck 11. Therefore, the warped wafer 1 can be adsorbed with a stronger adsorbing force than before.

  Further, the correction portion 21 is provided with a suction chuck opening 23 through which the suction chuck 11 passes. For this reason, the suction chuck 11 can suck the wafer 1 held by the correction unit 21 and the suction guard 31 while being held by the correction unit 21 and the suction guard 31. For this reason, when the suction chuck 11 sucks the wafer 1, the wafer 1 brought close to the flat state does not return to the original warped state. Thereby, the suction chuck 11 can suck the wafer brought close to a flat state. Therefore, the warped wafer 1 can be reliably sucked by the suction chuck 11.

  Further, according to the wafer holding method of the embodiment, the suction guard 31 is lowered while the wafer 1 is held by the suction force, and is brought into contact with the flat surface of the correction unit 21. For this reason, the wafer 1 is brought into contact with the flat surface of the correction unit 21 without being detached from the suction guard 31. Thus, the warped wafer 1 can be brought close to a flat state corresponding to the flat surface of the correction portion 21. Further, after the wafer is brought close to a flat state, it is sucked by the suction chuck 11. For this reason, a leak location (see FIG. 6) is not formed on the outer peripheral portion of the wafer holding surface of the suction chuck 11. Therefore, the warped wafer 1 can be adsorbed with a strong adsorbing force.

  As described above, the wafer 1 can be reliably sucked and held by the suction chuck 11 regardless of the state of warping of the wafer 1. For this reason, a wafer that has warped to the extent that it cannot be processed using a conventional automatic transfer mechanism or the like can be attracted and held by the wafer holding apparatus of the present invention. Thereby, for example, a process of spin-coating a resist that requires a high holding force can be performed using the wafer holding apparatus and the wafer holding method of the present invention.

  In the above description, the present invention has been described using the wafer warped in a concave shape on the front surface side. It can also be applied to cases. In this case, a leak portion is prevented from being formed on almost the entire wafer holding surface of the chuck. Moreover, you may apply to a flat wafer. Further, the shapes of the correction unit and the suction chuck are only examples, and other shapes may be used as long as the warp of the wafer can be corrected to approach a flat state before being sucked by the suction chuck.

  As described above, the wafer holding apparatus and the wafer holding method according to the present invention are useful when various processes are performed on the wafer or the wafer is transferred after the wafer is held.

DESCRIPTION OF SYMBOLS 1 Wafer 11 Suction chuck 12 Suction groove 13 Suction chuck support shaft 21 Correction section 22 Correction section support shaft 23 Suction chuck opening 24 Suction tube 31 Suction guard 32 Suction guard support shaft 33 Suction guard opening 34 Suction guard Step part

Claims (14)

A wafer holding device for sucking and holding a wafer,
Holding means for holding the outer peripheral portion of the wafer in which warpage occurs;
Correction means for bringing the wafer close to a flat state;
A suction means for sucking the central portion of the wafer;
With
A wafer holding apparatus, wherein after the holding means and the correcting means are relatively moved, the central portion of the wafer is sucked by the sucking means.   2. The wafer holding apparatus according to claim 1, wherein the holding unit holds the outer peripheral portion of the wafer by sucking the wafer while supporting the outer peripheral portion of the wafer in which the warpage occurs. .   3. The wafer holding apparatus according to claim 1, wherein the holding unit holds the wafer above the correction unit and then moves down until the wafer comes into contact with the correction unit.   4. The wafer holding apparatus according to claim 3, wherein the holding unit holds the wafer above the correction unit and then descends while sucking the wafer.   5. The wafer holding apparatus according to claim 3, wherein a portion of the correcting means that contacts the wafer is flat.   6. The wafer holding apparatus according to claim 1, wherein the correction means has an opening through which the suction means passes.   The wafer holding apparatus according to claim 6, wherein the suction unit sucks a portion of the wafer that is in contact with the correction unit that is exposed to the opening of the correction unit.   The wafer holding apparatus according to claim 2, wherein the correcting means has a ventilation hole through which air exhausted when the holding means sucks the wafer. A wafer holding method for adsorbing and holding a wafer,
A placing step of placing the warped wafer at a position facing the flat surface of a member having a flat surface;
After the placing step, a holding step for holding the outer periphery of the wafer;
A correction step of bringing the wafer having the outer periphery held by the holding step into contact with the flat surface;
An adsorption step for adsorbing a central portion of the wafer in contact with the flat surface;
A wafer holding method comprising: In the placing step, the wafer is placed above the flat surface,
The wafer holding method according to claim 9, wherein in the correcting step, the wafer is lowered and brought into contact with the flat surface.   11. The wafer holding method according to claim 9, wherein, in the holding step, the wafer is sucked in a state where the outer peripheral portion of the wafer in which the warpage is generated is supported.   The wafer holding method according to claim 9, wherein in the correction step, the wafer is lowered while being sucked.   The wafer holding method according to any one of claims 9 to 12, wherein, in the sucking step, a central portion of a surface of the wafer that is in contact with the flat surface is sucked.   14. The wafer holding method according to claim 9, wherein, in the sucking step, a portion of the wafer exposed to the opening of the member having the flat surface is sucked.

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