JP2008028175A - Wafer cleaning apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To remove both comparatively large particles firmly adhering on a wafer and comparatively small particles deposited in a recess of the surface of the semiconductor wafer. <P>SOLUTION: The wafer cleaning apparatus 10 is provided with a first cleaning head 12 having a first sponge brush 54 formed to be highly rigid so that it can remove the comparatively large particles 56 firmly adhering on the wafer 14, and a second cleaning head 13 having a second sponge brush 64 formed to be low-rigid so that it can remove the comparatively small particles 68 deposited in the recess of the wafer 14. In cleaning the wafer 14, the first cleaning head 12 is first driven to rotate the first sponge brush 54 in a state of abutting on the wafer 14. After that, the second cleaning head 13 is driven to rotate the second sponge brush 64 in a state of abutting on the wafer 14. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wafer cleaning apparatus that removes foreign matter adhering to the surface of a wafer.

Semiconductor manufacturing processes can be broadly divided into two processes: a pre-process for forming a plurality of identical devices on a disk-shaped wafer having an outer diameter of 150 mm to 300 mm, and a post-process for cutting chips from the wafer into a package. . Further, a wafer cleaning step for improving the yield by removing foreign matters (particles) such as fine dust and impurities adhering to the wafer surface is incorporated in the pre-process. In the wafer cleaning process, for example, as described in the following Patent Document 1 and the following Patent Document 2, a wafer cleaning apparatus that removes particles by bringing a sponge brush into sliding contact with the surface of a wafer is provided. Used.
Japanese Patent No. 3114156 JP 2004-273530 A

  However, in the conventional wafer cleaning apparatus, when the sponge brush has high rigidity, relatively large particles firmly attached to the wafer can be removed, but relatively small particles accumulated in the recess on the surface of the wafer cannot be removed. Further, when the sponge brush has low rigidity, relatively small particles accumulated in the recesses on the surface of the wafer can be removed, but relatively large particles firmly adhered to the wafer cannot be removed.

  The present invention has been made to solve the above problems, and is a wafer cleaning apparatus capable of removing both relatively large particles firmly attached to a wafer and relatively small particles accumulated in a recess on the surface of the wafer. The purpose is to provide.

  In order to achieve the above object, a wafer cleaning apparatus according to the present invention is a first cleaning apparatus in which a base side of a flexible first cleaning member is fixed in a wafer cleaning apparatus that removes foreign matter adhering to the surface of a wafer while supplying a cleaning liquid. The rotating plate, the second rotating plate that fixes the base side of the second cleaning member that is more flexible than the first cleaning member, and the leading ends of the first and second cleaning members are both substantially parallel to the surface of the wafer. And a rotating plate support mechanism to which the first and second rotating plates are mounted side by side in a direction substantially parallel to the surface of the wafer, and the rotating plate support mechanism includes the first and first rotating plates. A moving mechanism for moving each of the first and second rotating plates in a direction substantially perpendicular to the surface of the wafer so that one of the two cleaning members is selectively brought into contact with the surface of the wafer; The cleaning member is attached It is characterized in that the rotary plate is provided with a rotating mechanism for rotating in a plane substantially parallel to the surface of the wafer.

  The moving mechanism includes a first actuator that moves the first rotating plate, and a second actuator that moves the second rotating plate, and the rotating mechanism rotates a first motor that rotates the first rotating plate; And a second motor that rotates the second rotating plate.

  In addition, the first cleaning member is divided and arranged for each region obtained by dividing the first rotating plate by a straight line or a curve from the rotation center to the periphery, and a gap is provided at the boundary of each region. It is preferable.

  Further, the second cleaning member is divided and arranged for each region obtained by dividing the second rotating plate by a straight line or a curve from the rotation center to the periphery, and a gap is provided at the boundary of each region. It is preferable.

  The first cleaning member may be configured with polyvinyl alcohol as a main component, and the second cleaning member may be configured with polyurethane as a main component.

  According to the present invention, the wafer is cleaned using the first rotating plate provided with the first cleaning member and the second rotating plate provided with the second cleaning member that is more flexible than the first cleaning member. It is possible to provide a wafer cleaning apparatus capable of removing both relatively large particles firmly attached to a semiconductor wafer and relatively small particles accumulated in a recess on the surface of the semiconductor wafer.

  Further, the first cleaning member is divided and arranged for each region partitioned by a straight line or a curve from the rotation center of the first rotating plate toward the periphery, and a clearance is provided at the boundary of each region. Particles can be discharged efficiently to the outside of the rotating plate. Similarly, the second cleaning member is divided and arranged for each region partitioned by a straight line or a curve from the rotation center of the second rotating plate toward the periphery, and a clearance is provided at the boundary of each region. The particles can be efficiently discharged from the outside to the outside of the second rotating plate.

  In FIG. 1, a wafer cleaning apparatus 10 of the present invention is used in a wafer cleaning process incorporated in a semiconductor manufacturing process. The wafer cleaning apparatus 10 rotates a first cleaning head 12 or a second cleaning head 13, which will be described later, in contact with the surface of the wafer 14 in order to remove particles adhering to the wafer 14. The wafer cleaning apparatus 10 includes a support base 16, a nozzle 17, and a brush device 18, which are connected to a control unit 19 and driven and controlled.

  The support base 16 includes a base 20 and a rotary base 21 whose lower end side is rotatably attached to the base 20. An adsorption part (not shown) for adsorbing the wafer 14 is formed on the upper surface of the turntable 21, and the back surface of the wafer 14 is adsorbed by the adsorption part and fixed to the upper surface of the turntable 21. It rotates with the rotation of the turntable 21. The nozzle 17 is provided to supply a cleaning liquid to the wafer 14, and sprays a known cleaning liquid such as pure water or ammonia perwater (APM) onto the surface of the wafer 14 when cleaning the wafer 14.

  The brush device 18 includes an arm 22 that is long in the horizontal direction perpendicular to the surface of the wafer 14. The arm 22 is attached to an arm holding mechanism 24 with a shaft portion 22 a constituting a base end portion thereof. The arm holding mechanism 24 is held so as to be rotatable in a horizontal plane and movable in the vertical direction.

  In addition, a mount portion 30 to which the first and second cleaning heads 12 and 13 are attached is provided at the distal end portion of the arm 22. As shown in FIG. 2, the mount unit 30 includes a first drive mechanism 32 and a second drive mechanism 33, the first cleaning head 12 is in the first drive mechanism 32, and the second cleaning head 13 is in the second drive. Each of the mechanisms 33 is attached and held.

  The first drive mechanism 32 includes a motor 36 and a cylinder 38 and is driven and controlled by the control unit 19. The motor 36 has a shaft 36 a connected to the first cleaning head 12, and the cylinder 38 has a rod 38 a connected to the motor 36. The control unit 19 drives the motor 36 to rotate the shaft 36a, thereby rotating the first cleaning head 12 in the horizontal plane. The control unit 19 drives the cylinder 38 to move the rod 38a up and down. Accordingly, the first cleaning head 12 is moved between the cleaning position where the first cleaning head 12 is in contact with the wafer 14 and the standby position where the first cleaning head 12 is separated from the wafer 14 and stored in the storage unit 40 formed in the mount unit 30.

  Similar to the first drive mechanism 32, the second drive mechanism 33 includes a motor 42 and a cylinder 44, and is driven and controlled by the control unit 19. And the control part 19 rotates the 2nd washing | cleaning head 13 in a horizontal surface by driving the motor 42 and rotating the shaft 42a. Further, the control unit 19 drives the cylinder 44 to move the rod 44 a up and down, thereby separating the second cleaning head 13 from the cleaning position where the second cleaning head 13 is brought into contact with the wafer 14, and forming the mound 30. It is moved between the standby position for storing in the storage unit 46.

  The first cleaning head 12 is provided with a seal portion 52 on the upper surface of a head main body 50 formed in a disk shape. The seal portion 52 has a function of filling a gap between the head main body 50 and the inner wall of the storage chamber 40 and preventing particles and cleaning water from entering the mount portion 30. A first sponge brush 54 is provided on the lower surface of the head body 50. The first sponge brush 54 is composed of, for example, polyvinyl alcohol (PVA) as a main component, and is formed with high rigidity so as to remove relatively large particles 56 (see FIG. 5A) firmly attached to the wafer 14. Has been.

  On the other hand, the second cleaning head 13 is provided with a seal portion 62 on the upper surface of the head body 60 formed in a disk shape so that particles and cleaning water do not enter the mount portion 30. A second sponge brush 64 is provided on the lower surface of the head body 60. The second sponge brush 64 is made of, for example, polyurethane as a main component, and is formed with low rigidity so that relatively small particles 66 (see FIG. 5B) accumulated in the recesses of the wafer 14 can be removed.

  Further, as shown in FIG. 3, the first sponge brush 54 is provided with a cross-shaped cutout, and a groove 58 is formed by the cutout portion. Further, the second sponge brush 64 is provided with a cross-shaped cutout, and a groove 68 is formed by the cutout portion. These grooves 58 and 68 have a function of smoothly discharging the removed particles out of the cleaning heads 12 and 13 when the wafer 14 is cleaned.

  Hereinafter, the operation of the wafer cleaning apparatus 10 configured as described above will be described with reference to the flowchart shown in FIG. When cleaning the wafer 14, first, the wafer 14 is set on the support base 16 (S10). Subsequently, the control unit 19 drives the arm 22 to move the mount unit 30 above the wafer 14.

  Next, the controller 19 cleans the wafer 14 with the first cleaning head 12 (S11). That is, the control unit 19 drives the first drive mechanism 32 to move the second cleaning head 13 to the standby position, and to move the first cleaning head 12 to the cleaning position and rotate it. The cleaning is performed while spraying the cleaning liquid from the nozzle 17 onto the wafer 14 and rotating the support base 16 and the arm 22. Thereby, the entire surface of the wafer 14 is thoroughly cleaned by the first cleaning head 12.

  Subsequently, the control unit 19 cleans the wafer 14 with the second cleaning head 13 (S12). That is, the control unit 19 moves the first cleaning head 12 to the standby position and moves the second cleaning head 13 to the cleaning position and rotates it. This cleaning is also performed while spraying the cleaning liquid from the nozzle 17 to the wafer 14 and rotating the support base 16 and the arm 22, so that the entire surface of the wafer 14 is thoroughly cleaned by the second cleaning head 13.

  As shown in FIG. 5A, the first sponge brush 54 provided in the first cleaning head 12 has high rigidity and is difficult to deform. For this reason, in the cleaning by the first cleaning head 12, relatively large particles 56 firmly attached to the wafer 14 are removed. Further, as shown in FIG. 5B, the second sponge brush 64 provided in the second cleaning head 13 has low rigidity and is flexibly deformed according to the shape of the wafer 14. For this reason, in the cleaning by the second cleaning head 13, relatively small particles 66 attached to the recess of the wafer 14 are removed.

  As described above, the wafer cleaning apparatus 10 can remove both the relatively large particles 56 firmly attached to the wafer and the relatively small particles 66 attached to the recess of the wafer. Further, in the wafer cleaning apparatus 10, since the grooves 58 and 68 are provided in the first cleaning head 12 and the second cleaning head 13, respectively, the removed particles can be efficiently discharged out of the cleaning heads 12 and 13 and removed. The particles do not reattach to the wafer 14.

  In the above embodiment, an example in which two types of cleaning heads having different sponge brush rigidity are provided in the mount portion has been described. However, three or more types of sponge heads having different sponge brush rigidity may be provided in the mount portion. . Moreover, although the said embodiment demonstrated the example which uses a sponge brush as a washing | cleaning member, you may use the brush brush provided with the several brush hair as a washing | cleaning member.

  Furthermore, in the above-described embodiment, the first and second cleaning heads have been described with an example in which the groove portion extending linearly from the lower surface center portion to the end portion has been described. However, the first and second cleaning heads shown in FIG. Like each cleaning head 72 and 73, you may provide the groove parts 74 and 75 extended in circular arc shape toward the edge part from the center part of the lower surface of the cleaning heads 72 and 73. Of course, the present invention is not limited to this, and the presence or absence of the groove and the shape of the groove may be set as appropriate. In FIG. 6, members similar to those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

It is an external view of a wafer cleaning apparatus. It is sectional drawing of a mount part. It is the top view which observed the mount part from the lower part. It is a flowchart showing the washing | cleaning procedure of a wafer. It is explanatory drawing showing a mode that a particle is removed. It is the top view which observed the mount part from the lower part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Cleaning apparatus 12, 72 1st cleaning head 13, 73 2nd cleaning head 14 Wafer 19 Control part 30 Mount part 32 1st drive mechanism 33 2nd drive mechanism 32, 64 1st sponge brush 34, 66 2nd sponge brush 58 68, 74, 75 Groove

Claims (5)

In a wafer cleaning apparatus that removes foreign substances adhering to the wafer surface while supplying a cleaning liquid,
A first rotating plate that fixes the base side of the flexible first cleaning member;
A second rotating plate that fixes a base side of the second cleaning member that is more flexible than the first cleaning member;
The first and second rotating plates are mounted side by side in a direction substantially parallel to the surface of the wafer so that the front ends of the first and second cleaning members are both substantially parallel to the surface of the wafer. A rotating plate support mechanism,
Each of the first and second rotating plates is substantially placed on the surface of the wafer so that the rotating plate support mechanism selectively contacts one of the first and second cleaning members with the surface of the wafer. A wafer cleaning apparatus comprising: a moving mechanism for moving in a vertical direction; and a rotating mechanism for rotating a rotating plate on which the one cleaning member is mounted in a plane substantially parallel to the surface of the wafer. The moving mechanism includes a first actuator that moves the first rotating plate, and a second actuator that moves the second rotating plate,
2. The wafer cleaning apparatus according to claim 1, wherein the rotating mechanism includes a first motor that rotates the first rotating plate and a second motor that rotates the second rotating plate. 3.   The first cleaning member is divided and arranged for each region divided by a straight line or a curve from the rotation center toward the periphery, and a gap is provided at the boundary of each region. 3. A wafer cleaning apparatus according to claim 1, wherein   The second cleaning member is divided and arranged for each region divided by a straight line or a curve from the rotation center toward the periphery, and a gap is provided at the boundary of each region. The wafer cleaning apparatus according to any one of claims 1 to 3.   5. The wafer cleaning apparatus according to claim 1, wherein the first cleaning member includes polyvinyl alcohol as a main component, and the second cleaning member includes polyurethane as a main component.

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