JP5585911B2 - Wafer separation method and wafer separation transfer apparatus - Google Patents

Description

The present invention relates to partial Hanarekata method and wafer separating apparatus for transferring the wafer. More specifically, a material of the semiconductor device, to separate the wafer from the wafer stack group state where a large number of wafers are stacked, minute Hanarekata method of the wafer to be transferred to a predetermined position one by one the separated wafer And a wafer separation / transfer apparatus.

In the manufacture of a wafer used as a material for a semiconductor device, an ingot formed of silicon or the like is cut into a thin plate to form a stacked wafer group in which a large number of wafers are stacked. The laminated wafer group is separated and separated one by one.
As is well known, this wafer separation operation is a very difficult operation. As an apparatus for separating and stably supplying a wafer, for example, “Wafer separation / conveying device and separation / conveying device” Method "or" wafer single wafer apparatus and single wafer apparatus "described in Patent Document 2.

  The one described in Patent Document 1 includes a support member, a separating and extruding means, and an injection nozzle, and a large number of wafers are supported by the support member in a stacked state in the liquid, and a predetermined amount of the large number of wafers is supported by raising the support member Each wafer is lifted up and placed at the position near the water surface, and the top wafer is mechanically rotated by the contact of the separating and extruding means to give a starting force. Thus, water is sprayed to a position deviated from the center of the upper surface of the wafer at the water surface position, rotated in one direction, separated from other wafers, and conveyed in the unloading direction.

  In addition, the device described in Patent Document 2 sucks and holds a separation wafer by a first suction member, and sucks and holds the separation wafer by a second suction member at a position above the first suction member. The flexible pipe is contracted to attract and hold the warped wafer while it is warped, and then the upper part of the outer peripheral surface of the adjacent wafer is pressed by a stopper to prevent the adjacent wafer from moving along with the movement of the separated wafer. By separating the wafer from the laminated wafer group, the wafers can be reliably removed from the laminated wafer group one by one without requiring strict gap management.

JP-A-9-148278

JP 2002-75922 A

  However, as described above, the device described in Patent Document 1 describes that “the uppermost wafer is mechanically rotated by the contact of the separating and extruding means to apply a starting force, and the wafer at the water surface position is further applied by the spray nozzle. Water is jetted to a position deviated from the center of the upper surface and rotated in one direction. For this reason, the moving frictional resistance is considerably increased at the contact surface between the uppermost wafer and the other wafer, and both wafers are subjected to great stress particularly when starting by the separation extrusion means. It is difficult to separate the wafer and the wafer may be damaged.

  In addition, as described in Patent Document 2, as described above, “the first wafer is sucked and held by the first suction member, and the second wafer is sucked and held by the second suction member at a position above the first suction member. The flexible pipe of the second adsorbing member is contracted to hold the separated wafer while adsorbing and holding it ”. For this reason, the separated wafer is subjected to a large stress due to deformation and may be damaged.

(Object of the present invention)
Accordingly, an object of the present invention is a material for a semiconductor element, in an operation of separating a wafer from a laminated wafer group in which a large number of wafers are laminated and transferring the separated wafers one by one to a predetermined location. by preventing breakage so as not give as much as possible the stresses caused by friction or deformation to the wafer to be separated and to allow stable supply of wafer further improve the yield of the wafer, minute Hanarekata method of the wafer And a wafer separation transfer apparatus.

  Means taken by the present invention to solve the above problems are as follows.

(1) The present invention is a wafer separation method for separating a wafer from a laminated wafer group in which a large number of wafers are laminated, and the front side is lowered so that the center of the discharge port at the front end is the height of the water surface. by discharging water from the discharge nozzle is inclined, the steps of producing a mixed stream containing water and a plurality of air bubbles in water, when the laminated wafer group has risen to the water surface near the left and right of the laminated wafer group Morozumi And a step of separating the wafer from the laminated wafer group by flowing a mixed flow toward the part and applying the mixed flow to both sides and the front surface of the laminated surface.

(2) The present invention is the wafer separation method according to (1), wherein the angle of the discharge nozzle with respect to the water surface is 15 ° to 40 °.

(3) The present invention is a wafer separation transfer device for transferring a predetermined portion to separate the wafer from the wafer stack group state where a large number of wafers are stacked, the water surface is the center of the discharge port of the tip causing the discharge nozzle front side so that the height of the is inclined downward by ejecting water mixture stream comprising water and a large number of air bubbles in water, when the laminated wafer group has risen to the water surface near the a discharge nozzle hit the side surfaces and the front surface of the laminate surface by flowing the mixed stream towards the left and right corners of the laminated wafers group, holding the stacked wafers group, the laminated wafer group the mixed flow is the position corresponding to the laminated surface a wafer feeder for moving a wafer separation transfer device to obtain Bei and holds the web Ha separated et or laminated wafers groups wafer transfer unit for transferring the predetermined箇plants by the mixed flow.

(4) The present invention is the wafer separation / transfer apparatus according to (3), wherein an angle of the discharge nozzle with respect to a water surface is 15 ° to 40 ° .

  The term “laminated surface” in the present specification and claims is used to mean the side surface of a laminated wafer group, that is, the surface on which the thickness of each wafer laminated is shown.

(Function)
The operation of the wafer separating / transferring apparatus according to the present invention will be described. Here, the constituent elements used in the description are assigned in correspondence with the reference numerals given to the respective parts in the embodiments described later. These reference numerals are the same as the reference numerals described in the claims of the claims. Similarly, it is only for the purpose of facilitating understanding of the contents, and the meaning of each component is not limited to the above-described parts.

First, a mixed flow containing water and a large number of bubbles (B) is generated in the water in the water tank (2) by discharge means (discharge nozzles (3, 3a), etc.). The ejection timing may be after moving the laminated wafer group (7) to a required position.
Next, the laminated wafer group (7) is held by a wafer supply means (wafer feeder (4) or the like), and the laminated wafer group (7) is moved to a position where the mixed flow hits the laminated surface.

  As a result, water and bubbles (B) enter between the wafers (70) constituting the laminated wafer group (7), for example, a plurality of wafers (70) near the upper surface side of the laminated wafer group (7) gradually. Separation and gaps between each wafer (70) allow water and bubbles (B) to enter further, and the separated wafer (70) can be separated without excessive stress due to friction, deformation, etc. it can.

  In addition, a large number of bubbles (B) enter between each wafer (70), and these bubbles (B) function as a cushion (buffer material), so that each of them is separated and suspended in water. The wafers (70) are unlikely to contact or collide with each other, thereby preventing the wafer (70) from being damaged. Furthermore, a large buoyancy is imparted to the wafer (70) separated by a large number of bubbles (B), whereby the wafer (70) is separated in a shorter time.

  Of the separated wafers (70), the uppermost wafer (70) is held by the wafer transfer means (wafer transfer machine (5), etc.) and transferred to a predetermined location (62). . Thereafter, the wafer is taken out from the transfer location (62) and sent to the subsequent process.

The present invention is a material for a semiconductor device, and in the operation of separating a wafer from a laminated wafer group in which a large number of wafers are laminated, and transferring the separated wafers one by one to a predetermined location, By separating the wafer by applying a water flow (mixed flow) containing water to the lamination surface of the laminated wafer group, it is possible to prevent damage to the separated wafer without applying a large stress due to friction or deformation. it can.
Specifically, a large number of bubbles enter between the wafers that are separated, and these bubbles function as a cushion, so that the wafers that are separated and floating in water are less likely to contact or collide with each other. This prevents the wafer from being damaged. Furthermore, a large buoyancy is imparted to the wafer that is separated by a large number of bubbles, thereby separating the wafer in a shorter time.
Thereby, the yield of the wafer can be further improved and the wafer can be supplied stably.

The perspective explanatory view seen from the front which shows one embodiment of the wafer separation transfer equipment concerning the present invention. The perspective explanatory view which looked at the wafer separation transfer equipment from back. The front view which shows the structure of a wafer separation transfer equipment. The top view which shows the structure of a wafer separation transfer apparatus. The right view which shows the structure of a wafer separation transfer apparatus. The left view which shows the structure of a wafer separation transfer apparatus. XX cross-sectional explanatory drawing in FIG. YY cross-sectional explanatory drawing in FIG. Explanatory drawing which shows the process until the wafer isolation | separation by a wafer separation transfer apparatus. Explanatory drawing which shows the process until the transfer after the separation of the wafer by a wafer separation transfer equipment. The initial state of a lift member is shown, (a) is explanatory drawing on the left side view, (b) is explanatory drawing on the top view. The state which mounted the laminated wafer group on the lift member is shown, (a) is left side explanatory drawing, (b) is top view explanatory drawing. The state which raised the laminated wafer group to the isolation | separation operation position with the lift member is shown, (a) is left side explanatory drawing, (b) is top view explanatory drawing. The state which applied the mixed flow to the lamination | stacking wafer group and has isolate | separated the several wafer is shown, (a) is left side explanatory drawing, (b) is top view explanatory drawing.

The present invention will be described in detail based on the embodiments shown in the drawings.
Please refer to FIG. 1 to FIG. 8 and FIG. 11 to FIG.
1 to 8, for convenience, a laminated wafer group 7 in a state where a large number of wafers are laminated and a single wafer 70 separated from the laminated wafer group 7 are also shown.

The wafer separating / transferring apparatus A separates the wafer 70 from the laminated wafer group 7 and transfers it to a predetermined location (in this embodiment, a transfer receiver 6 described later).
The wafer separating / transferring apparatus A has a frame 1 assembled with square pipes. The frame 1 holds the discharge nozzles 3, 3 a and the laminated wafer group 7 disposed at the water surface position of the water tank 2, the water tank 2, and holds the laminated wafer group 7 to the water inlet portion by the discharge nozzles 3, 3 a on the water surface side. A wafer feeder 4 to be moved, a wafer transfer device 5 for holding and transferring the wafer 70 separated from the laminated wafer group 7, and a transfer receiver 6 for receiving the wafer 70 from the wafer transfer device 5 are incorporated.

  The water tank 2 is fixed to the lower part of the frame 1. The water tank 2 is filled with a predetermined amount of clean water, and the height of the water surface is maintained constant. In the water tank 2, discharge nozzles 3, 3a are arranged at two locations. Clean water is supplied to the discharge nozzles 3 and 3a. The discharge nozzles 3 and 3a are fixed to the water tank 2 with the front side inclined downward at a required angle (for example, an angle of 15 to 40 ° with respect to the water surface) so that the center of the discharge port 30 at the tip is the height of the water surface. Has been.

Further, in the present embodiment, the discharge nozzles 3 and 3a, when the laminated wafer group 7 rises to the vicinity of the water surface, as will be described later, from both sides (left and right sides in FIG. 3) to the left and right corners of the laminated wafer group 7 The mixed flow flows toward the opposite side of the laminated surface, and the mixed flow effectively hits both sides and the front surface (see FIG. 14B).
The position (height) and the inclination angle of the discharge nozzles 3 and 3a are not limited to the above, but at least water discharged from the discharge nozzles 3 and 3a takes in air at the surface of the water, and water and a large number of bubbles are generated in the water. It is set to a position and an inclination angle at which the mixed flow including it occurs.

  The wafer feeder 4 has a base frame 46 fixed to the bottom of the water tank 2. A square support plate 40 is fixed at the center of the base frame 46. The support plate 40 is inclined at an angle of 15 to 40 ° with the bottom surface (or the water surface) of the water tank 2 so that the front side (the right side in the left side view of FIG. 6) is higher. In the present embodiment, the angle of the support plate 40 is set to be the same as the angle at which water is discharged from the discharge nozzles 3 and 3a with respect to the water surface, but is not limited thereto. Two guide pins 41 are fixed to the upper surface of the three sides excluding one side on the front side of the support plate 40 at a required interval per side in a direction perpendicular to the support plate 40 (FIG. 11A). (See (b)).

  Each guide pin 41 is set at a position where the laminated surface of the three side portions of the prismatic laminated wafer group 7 fits inside with a slight gap, and the laminated wafer group 7 from one side where the guide pin 41 is not provided. Can be stored. Note that the support plate 40 and the guide pins 41 of the present embodiment correspond to a square wafer, but guide pins are provided on the same three sides of the support plate 40, for example, so as to be compatible with a circular wafer. It is good also as a structure provided one by one.

  Of each guide pin 41, plate-like stoppers 42 are parallel to each other on the upper portions of the guide pins 41 on two opposite sides (left and right sides in FIG. 3) of the support plate 40. It is fixed. Each stopper 42 is used to stop the separated wafer 70 from being removed from the position where the separated wafer 70 is attracted by the wafer transfer device 5 when the wafer 70 is separated from the laminated wafer group 7, and is fixed in parallel to the support plate 40. .

  The wafer feeder 4 has a lift member 43 on which the laminated wafer group 7 is placed. The lift member 43 is positioned on the upper surface side of the support plate 40 and is fixed in a cantilever structure to the lower end of the transition body 45 of the drive device 44 fixed to one side (right side in FIG. 3) of the frame 1. . The mounting portion of the lift member 43 is parallel to the support plate 40, and the lift member 43 is moved up and down in a direction parallel to the guide pin 41 by a ball screw type driving device 44.

  The wafer transfer machine 5 has a guide body 50 having a required length fixed to the other side of the frame 1 (left side in FIG. 3). The guide body 50 is inclined at an angle of 15 to 40 ° with the bottom surface of the water tank 2 so that the front side is higher. In the present embodiment, the angle is set to be the same as the angle of the support plate 40, but is not limited. A transition body 51 is attached to the guide body 50 so that the transition body 51 can be moved along the guide body 50 by a ball screw type driving device 52.

  The transition body 51 includes an actuator 52 and a lifting arm 53 that is lifted and lowered by the actuator 52. A vacuum suction part 54 is provided in a cantilever structure at the lower end of the lifting arm 53. The transition body 51 can position the vacuum suction portion 54 above the guide pins 41 of the stacked wafer group 7 placed on the lift member 43 in the height direction, and the vacuum suction portion 54 sucks the separated wafer 70. be able to. The direction in which the elevating arm 53 moves up and down is perpendicular to the direction of the guide body 50.

The transfer receiver 6 is fixed to one side (right side in FIG. 3) on the front side of the frame 1, and the mounting height of the transfer receiver 6 is in the vicinity of the height of the upper edge of the water tank 2 when the rising stop position of the receiving plate 62 described later It is set to become.
The transfer receiver 6 includes an actuator 60 and a lifting body 61 that is lifted and lowered by the actuator 60, and a receiving plate 62 is provided in a cantilever structure at the lower end of the lifting body 61. The receiving plate 62 is inclined so as to be parallel to the support plate 40, that is, to be parallel to the wafer 70 that is sucked and sent by the vacuum suction portion 54.

  On the upper surface of the receiving plate 62, there is provided a mounting recess 63 into which the transferred wafer 70 is fitted so as not to fall. The mounting recess 63 has a stepped portion on the rear side and no stepped portion on the front side (see FIG. 8), and the transferred wafer 70 is slid obliquely upward (forward direction). It can be taken out.

The cradle plate 62 is moved up and down in a direction perpendicular to the surface direction of the cradle plate 62 by the actuator 60. The rising stop position of the receiving plate 62 is set to a height at which the wafer 70 sucked by the vacuum suction unit 54 enters the mounting recess 63 when the lifting arm 53 of the wafer transfer device 5 is lowered. Yes.
Further, although the transfer receiver 6 is provided in the present embodiment, the wafer transfer machine 5 is not provided but is provided in an apparatus for sending the separated wafer 70 to a subsequent process, for example, a transfer machine having a known structure. It is also possible to adopt a structure in which the wafer 70 is directly transferred.

(Function)
1 to 14, the wafer separation / transfer apparatus A and the wafer separation / transfer apparatus A separate a wafer from a laminated wafer group in which a large number of wafers are laminated, and one separated wafer. The process of transferring to a predetermined location one by one will be described.

(1) The states shown in FIGS. 9A, 11A, and 11B are initial states, and the lift member 43 of the wafer supply machine 4 is lowered to the lowest position. The transition body 51 having the lifting arm 53 is in the front position, and the lifting arm 53 and the vacuum suction part 54 are in the upper position.
(2) The laminated wafer group 7 is placed on the lift member 43 of the wafer feeder 4 and accommodated inside each guide pin 41 (see FIGS. 9B, 12A, and 12B). .

(3) The driving device 44 operates to raise the laminated wafer group 7 together with the lift member 43 (see FIGS. 13A and 13B). Then, water is discharged into the water from the discharge nozzles 3 and 3a at a required pressure. The discharged water takes in air when entering the water surface, and a mixed flow including water and a large number of bubbles B is generated in the water (see FIGS. 9C and 14A).

(4) The lift member 43 stops at the separation work position where the mixed flow hits the upper laminated surface of the laminated wafer group 7, and from both the left and right sides of the laminated wafer group 7 to the left and right corners of the laminated wafer group 7. The mixed flow flows toward the both sides of the laminated surface and the front surface. It should be noted that the mixed flow can be applied to other positions on the laminated surface as long as the separation of the wafer 70 is not hindered.
As a result, the plurality of wafers 70 are separated so as to be lifted from the laminated wafer group 7 inside each guide pin 41 by the mixed flow, and the uppermost wafer 70 is stopped below the stopper 42 (see FIG. 14A). ). Then, the transition body 51 of the wafer transfer device 5 moves to the rear wafer suction position (see FIG. 9D).
When the wafers 70 are separated, water and bubbles B enter between the wafers 70, and the wafers 70 to be separated can be separated without excessive stress due to friction or deformation. In addition, since the bubbles B that enter between the wafers 70 function as a cushion, the wafers 70 that are separated and floating in water are unlikely to contact or collide with each other, thereby damaging the wafers. Can be prevented. Furthermore, a large buoyancy is imparted to each wafer 70 to be separated by the large number of bubbles B, whereby the wafer 70 is separated in a shorter time.

(5) The elevating arm 53 of the wafer transfer device 5 is lowered, and the uppermost wafer 70 separated from the laminated wafer group 7 and positioned below the stopper 42 is adsorbed by the vacuum adsorbing unit 54 (FIG. 10 ( e)). The position at which the uppermost wafer 70 is adsorbed is underwater slightly below the lower surface of the stopper 42 (in FIG. 14A, a part of the front side of the wafer 70 protrudes from the water surface, but the whole is underwater. It is possible to prevent damage to the stopper 42 when it is moved toward the transfer receiver 6.

(6) The driving device 52 operates in a state where the uppermost wafer 70 is sucked by the vacuum suction portion 54 of the lifting arm 53, and the transition body 51 moves forward and stops at a predetermined position (see FIG. 10 (f)). .
The mixed flow continuously strikes the laminated wafer group 7 and the separated wafers 70, and after the uppermost wafer 70 has moved, the next wafer 70 is stopped under the stopper 42. Further, the laminated wafer group 7 is gradually raised by the lift member 43 so that the entire laminated wafer group 7 is separated into the wafers 70.

(7) The actuator 60 (see FIGS. 1 and 2) of the transfer receiver 6 operates, and the receiving plate 62 rises and stops at a predetermined position. The suction state of the wafer 70 by the vacuum suction portion 54 is released, and the wafer 70 is transferred to the mounting recess 63 of the receiving plate 62 (see FIG. 10G, FIG. 7 and FIG. 8).
(8) The receiving plate 62 descends and returns to the original position. Moreover, the raising / lowering arm 53 raises (refer FIG.10 (h)).

  As a result, the process returns to the (3) end state, and the processes of (4) to (8) are repeated until the wafer 70 constituting the laminated wafer group 7 runs out, and the wafer 70 is separated. The wafer transferred to the transfer receiver 6 is sequentially sent to the subsequent process.

In order to confirm the effectiveness and superiority of the wafer separating / transferring apparatus A of the present embodiment, (1) When a mixed flow of water and air is discharged in water (this embodiment), (2 ) When only water was discharged in water, (3) In each case where only air was discharged in water, comparative verification was performed (see Table 1).
Specifically, each fluid is discharged toward the lamination surface of the laminated wafer group in the water tank, and the separation time when separating the uppermost wafer is measured. After the uppermost wafer is separated, the fluid is moved up and down. The NG probability (defective rate) until the wafer was transferred by the arm was verified.

(Discussion)
First, regarding the wafer separation time, the case of (1) in which the mixed flow of water and air in the present embodiment is discharged is shorter than the case of (2) in which the discharge method is only water. The wafer could be separated. This is presumably because a large number of air bubbles enter between the stacked wafers together with water to promote separation of the wafers by imparting a large buoyancy to the uppermost wafer.

  In addition, regarding the NG probability at the time of wafer transfer, in the case of (2) where the discharge method is only water, the wafer transfer error due to wafer cracking due to unstable wafer separation, adsorption failure, and wafer In the case of (1) in which the mixed flow of water and air (bubbles) in the present embodiment is discharged, no NG occurs and the NG probability is 14%. Superiority was recognized.

In the case of discharging only air (3), the flow of air (bubbles) in water was not stable and the wafer was damaged. Further, when the air flow rate is reduced to such an extent that the wafer is not damaged, the flow rate is insufficient to separate the wafer, and as a result, verification is difficult.
Thus, in the above three cases, it was found that it is most effective to separate the wafers by the method (1) of discharging the mixed flow of water and air (bubbles).

  Note that the terms and expressions used in this specification are merely explanatory and are not limiting at all, and terms and expressions equivalent to the features described in this specification and parts thereof. There is no intention to exclude. It goes without saying that various modifications are possible within the scope of the technical idea of the present invention.

A Wafer Separation / Transfer Device 1 Frame 2 Water Tank 3, 3a Discharge Nozzle 30 Discharge Port 4 Wafer Feeder 40 Support Plate 41 Guide Pin 42 Stopper 43 Lift Member 44 Drive Device 45 Transition Body 46 Base Frame 5 Wafer Transfer Machine 50 Guide Body DESCRIPTION OF SYMBOLS 51 Transition body 52 Actuator 52 Drive apparatus 53 Lifting arm 54 Vacuum suction part 6 Transfer receiver 60 Actuator 61 Lifting body 62 Receptacle plate 63 Mounting recessed part 7 Laminated wafer group 70 Wafer B Bubble

Claims (4)

A wafer separation method for separating a wafer from a laminated wafer group in which a plurality of wafers are laminated,
End center of the discharge port discharges the water from the discharge nozzle is the front side so that the height of the water surface is inclined downward in the step of resulting mixed stream containing water and a plurality of air bubbles in water,
A step of separating the wafer from the laminated wafer group by flowing a mixed flow toward the left and right corners of the laminated wafer group and hitting both sides and the front surface of the laminated surface when the laminated wafer group rises to the vicinity of the water surface. A wafer separation method. The angle of the discharge nozzle with respect to the water surface is 15 ° to 40 °.
The method for separating a wafer according to claim 1. A wafer separating and transferring apparatus for separating a wafer from a laminated wafer group in a state where a large number of wafers are laminated and transferring the wafer to a predetermined location,
Causing tip mixed stream center of the discharge port comprises a front side is inclined downward to a large number of water in the water by discharging water from the discharge nozzle and bubble so that the height of the water surface, the laminated wafer group A discharge nozzle that, when raised to the vicinity of the water surface, flows the mixed flow toward the left and right corners of the laminated wafer group and hits both sides and the front surface of the laminated surface ;
Holding the laminated wafers group, a wafer feeder which the mixed flow is to move the wafer stack groups position corresponding stacking surface,
Wafer separation transfer apparatus and a wafer transfer unit for transferring a predetermined箇plant holds web Ha separated et or laminated wafers group by the mixed flow. The angle of the discharge nozzle with respect to the water surface is 15 ° to 40 °.
The wafer separation / transfer apparatus according to claim 3 .

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