JPH02283021A - Semiconductor wafer retaining equipment - Google Patents

Abstract

PURPOSE:To surely retain a semiconductor wafer and enable washing both surfaces by retaining the outer periphery of the wafer with chuck pawls in a state where the semiconductor wafer is separated from the surface of a chuck main body, and retaining the wafer by pressing the chuck pawls with elastic members. CONSTITUTION:By a conveying means, a semiconductor wafer 1 is moved downward and guided up to the recessed parts 12c, 12d of chuck pawls 12a, 12b. Then the supply of compressed air from a compressor is halted; the air pressure in air cylinders 14a, 14b returns the atmospheric pressure; by the effect of compression springs 15a, 15b, the chuck pawls 12a, 12b are moved in the inner radius direction, and set at a position shown by a full line; the semiconductor wafer is retained in the manner in which the outer periphery is sandwiched by the pawls from both ends. After that, the chuck main body 11 is rotated by the rotation of a motor 5, and drops of water which have attached on the surface of the semiconductor wafer 1 are shook off and eliminated by the effect of centrifugal force.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a semiconductor wafer holding device used in a process of cleaning semiconductor wafers.

(Prior art) Many processing steps are required when manufacturing semiconductor devices, and one of the most important steps is a scrubbing step to remove unnecessary substances such as dust attached to the surface of a semiconductor wafer. There is.

In this step, first, unnecessary substances on the surface of the semiconductor wafer are rubbed off with, for example, a rotating brush, and then washed with pure water. After that, it is necessary to remove water droplets from the wafer surface, but conventionally the fifth
A holding device as shown in FIG. 6 and its top view was used.

The semiconductor wafer 1 transported by a transport mechanism (not shown) is guided into the processing container 3 and placed on the chuck body 42 . A hole 42a is provided on the upper surface of this chuck body 42, and an air passage 43 that communicates with this hole 42a is provided inside. This passage is connected to a vacuum device (not shown) via a vacuum pipe 41, and internal air is exhausted to create a negative pressure and the semiconductor wafer 1 is attracted to the upper surface of the chuck body 42. The semiconductor wafer 1 is rotated in the direction of the arrow by the drive motor 5 connected to the chuck body 42, and water droplets on the wafer surface are removed by centrifugal force.

(Problem to be solved by the invention) However, there is a limit to the suction power due to vacuum pressure, and
If the vacuum pressure provided by the vacuum device is reduced, the holding force of the semiconductor wafer 1 may also be reduced, resulting in instability.

Also, even if you try to increase the diameter of the semiconductor wafer 1,
There was a limit due to holding power.

Further, when not only the front surface but also the back surface of the semiconductor wafer 1 is cleaned, water droplets are also attached to the back surface of the wafer, but it is impossible to remove the water droplets from the portion in contact with the chuck body 42. Furthermore, the water droplets on the back side of the chuck body 4
The semiconductor wafer 1 may fall off from the chuck body 42 and be damaged due to the suction from the holes 42a of the chuck 2 and the accumulation inside the air passage 43 and the vacuum tube 41, resulting in a decrease in the suction force. Therefore, in the past, there was a problem that only one side of the semiconductor wafer 1 could be cleaned.

In view of the above circumstances, it is an object of the present invention to provide a semiconductor wafer holding device that can securely hold a semiconductor wafer and also allows cleaning not only one side but both sides.

[Structure of the invention]

(Means for Solving the Problems) The present invention includes a chuck body, at least two chuck jaws supported by the chuck body so as to move in the radial direction, and an elastic body that presses each of the chuck jaws in the radial direction. and a chuck body support part that rotatably supports the chuck body, and supports the outer edge of the semiconductor wafer inside the chuck jaws so that the semiconductor wafer is held at a position apart from the surface of the chuck body. It is characterized by having a recessed part in each of them.

It also includes a chuck body having at least two air cylinders positioned so that their centers face each other in the radial direction, a piston that is inserted into the air cylinders and moves in the radial direction, and an elastic force that presses the pistons inward in the radial direction. a chuck jaw fixed to a piston protruding from the chuck body and provided with a similar recess; a compressor for feeding compressed air into an air cylinder to press the piston radially outward; and a chuck supporting the chuck body. It may also include a main body support part.

Here, the chuck pawl may include a counterweight that is provided on the opposite side of the rotation center and generates a centrifugal force in a direction different from that of the chuck pawl when rotated.

Furthermore, there is a flat plate that rotates together with the chuck body, a sensor unit that is provided on the rotating circumference of this flat plate to detect a predetermined location on the flat plate, and a sensor unit that detects this location after the rotation drive unit stops rotating. The chuck body may further include a stop position control unit that rotates the chuck body until the chuck body stops in a fixed direction.

(Function) The outer edge of the semiconductor wafer is supported by the recess of the chuck claw, and the chuck claw is pressed and moved in the radial direction by the elastic body, so that the semiconductor wafer is held at a position away from the surface of the chuck body. . This allows the semiconductor wafer to be placed in a state where only the outer edge is in contact with other things.
It will be held by mechanical elastic force.

If the chuck main body has an air cylinder, after the semiconductor wafer is held in the same manner as described above, when compressed air is sent into the cylinder by the compressor, the piston carried forward by the chuck jaws will move radially outward. The holding of the semiconductor wafer is released by being pressed by and moving inside the cylinder.

The chuck jaws tend to open radially outward due to centrifugal force during rotation, but by using a counterweight, centrifugal forces in different directions are generated and offset, and the semiconductor wafer does not fall off the chuck jaws.

When the chuck body is rotated by the stop position control unit until the sensor unit detects a predetermined position on the flat plate and then stopped, the stop position of the chuck body faces in a fixed direction.

(Example) Hereinafter, the first example, which is an example of the present invention, will be described.
This will be explained with reference to the figure and FIG. 2, which is a plan view thereof. In contrast to the conventional device described above, which uses suction force due to vacuum pressure to attract and hold the back surface of the semiconductor wafer 1,
This embodiment is different in that the outer edge of the wafer 1 is held from both sides using mechanical elastic force.

The chuck body 11 is rotatably supported by a chuck body support portion 17 fixed on a table 18.

This chuck body 11 has the following components. The chuck claws 12a and 12b are provided to face each other, and the outer edges of the semiconductor urchins are connected to the recesses 12c and 12b.
2d and supports it from both sides. This chuck claw 12a.

Pistons 21a respectively connected to pistons 12b.

21b is a compression spring 15 that moves in the radial direction within the air cylinders 14a and 14b, and is an elastic body.
a, 15b are suppressed radially inward.

The air passage 23 is a pipe connecting the air cylinders 14a, 14b and the air tube 4, and allows compressed air from a compressor (not shown) connected to the air tube 4 to pass in the direction of the arrow to connect the air cylinders. 14a and 14b. The air seal 19 prevents compressed air from leaking between the chuck body support portion 17 and the air passage 16.

The motor 5 is for rotating the chuck body 11 as in the conventional apparatus, and the processing container 3 is for receiving the cleaning liquid.

The operation of this embodiment having such a configuration will be explained. A semiconductor wafer 1 transported by a transport means (not shown) is placed in a chuck body 1 inside a processing container 3.
1. At this stage, compressed air passes through the air tube 4, the air passage 16, and the air cylinder 14a.
This air pressure is fed into the compression spring 14b.
5a.

The elastic force of the piston 21a is superior to that of the elastic force of the piston 15b.

21b has moved radially outward. As a result, the chuck claws 12a and 12b are located at the positions indicated by the dashed lines, and the distance between them is greater than the diameter of the semiconductor wafer 1.

The semiconductor wafer 1 is moved downward by the transport means, and the recesses 12c of the chuck claws 12a and 12b are moved.

Guide to position 12d. After that, when the supply of compressed air from the compressor is stopped, the air cylinders 14a and 14b
The air pressure inside returns to atmospheric pressure, and the chuck claws 12a, 12b move radially inward due to the action of the compression springs 15a, 15b to the position shown by the solid line, and the semiconductor wafer 1
Hold the outer edge from both ends.

Thereafter, the chuck body 11 is rotated by the rotation of the motor 5, and the water droplets attached to the surface of the semiconductor wafer 1 are removed.
It is shaken off and removed by centrifugal force.

In this case, a centrifugal force is applied to the chuck jaws 12a and 12b that tends to cause them to move away from each other, but a counterweight is provided to prevent this. The chuck jaw 12a has counterweights 13a and 13c, and the chuck jaw 12b has counterweights 13b and 13.
d are respectively attached to opposite sides of the rotation center 22, the centrifugal forces act in opposite directions and cancel each other out. This prevents the chuck claws 12a, 12b from expanding outward and prevents the semiconductor wafer 1 from falling off.

After removing the water droplets, when compressed air is sent into the air cylinders 14a and 14b again, the chuck jaws 12a
, 12b open outward, and the holding of the semiconductor wafer 1 is released.

In this way, according to the first embodiment, the outer edge of the semiconductor wafer \1 is held between both ends by mechanical elastic force, so the holding force is high, and the holding force is high, unlike when the semiconductor wafer is held by vacuum pressure. , problems such as a decrease in holding force are solved. Therefore, it is possible to cope with the increase in the diameter of semiconductor wafers.

Furthermore, since the wafer is held only at its outer edge, water droplets can be removed not only from the front surface but also from the back surface, making it possible to clean both surfaces of the semiconductor wafer.

Further, by sending compressed air into the air cylinders 14a and 14b, the wafer can be easily released from being held, so that work efficiency can be improved.

Next, a second embodiment will be described using FIG. 3 showing its configuration and FIG. 4 showing its plan view.

This embodiment is different from the first embodiment in that it further includes a stop position control section that makes the stopping direction of the chuck body 11 constant so that the guide rail 42 and the chuck section 11 in the conveying device do not interfere with each other. It is. Components that are the same as those in the first embodiment are given the same numbers and description thereof will be omitted.

The guide rail 42 is used to carry the semiconductor wafer 1 on it, and is located at the narrow position B between the guide rails during the transfer, and moves in parallel to the position B after the transfer. Disk 9 is motor 5
It is connected to a rotating shaft 5a, and has a groove 31a on the circumference. The sensor 32 is a transmission type photosensor, and is provided so as to sandwich the outer periphery of the disk 31, and is turned on when the disk 31 rotates and light passes through the groove 31a.

The position of this groove 31a is related to the directionality of the chuck body 11, and as shown in FIG. Sometimes, the position is such that it is detected by the sensor 32. The electromagnetic clutch 34 is connected to the rotating shaft 5a by a timing belt 33,
The rotation of the motor 5 is detected. The clutch is in a disengaged state while rotating, and is engaged when rotation stops. The pulse motor 35 starts driving when the electromagnetic clutch 34 is connected,
The chuck body 11 is rotated via the electromagnetic clutch 34 and the timing belt 33 until the sensor 32 detects the groove 31a.

The control operation of the stop position in the third embodiment having such a configuration will be explained. The semiconductor wafer 11 mounted on the guide rail 42 at position B is conveyed to a position on the upper surface of the chuck body 11. At this stage, the processing container 3 is positioned below so as not to interfere with the guide rail 42. Moreover, the chuck body 11 is stopped in a direction that does not interfere with the guide rail 42 as shown in FIG. 4 by the operation described later.

The guide rail 42 descends downward, and the chuck claws 12a,
The semiconductor wafer 1 is guided to the position of the recess 12b,
It is held in the same manner as in the first embodiment. Guide rail 4
2 moves to position B, the processing container 3 moves upward to the position shown in FIG. The motor 5 rotates, and when the removal of water droplets from the surface of the semiconductor wafer 1 is completed, this rotation is stopped. The electromagnetic clutch 34 that detected this stoppage
is connected, and the pulse motor 35 starts rotating. The pulse motor 35 is interlocked with the sensor 32, and stops rotating when the sensor 32 detects the groove 31a of the disc 31. As a result, the chuck body 11 is stopped in a direction that does not interfere with the guide rail 42 even when it is in the position B. Here, the reason why the stop position of the chuck body 11 is controlled using the pulse motor 35 without directly controlling the rotation of the motor 5 is as follows.
This is because with a conventional drive motor, it is difficult to accurately stop the motor at a fixed position after rotation.

After this, the processing container 3 moves downward. Guide rail 4
After moving from position A to position B, wafer 2 rises, mounts semiconductor wafer 1 thereon, and transports it to a predetermined location.

As described above, according to the second embodiment, by controlling the stop position of the chuck body 11, it is possible to prevent it from interfering with the guide rail.

The above embodiments are merely examples and do not limit the present invention. For example, in both the first and second embodiments, the semiconductor sea urchin /\ is released by sending compressed air to an air cylinder. It may be operated to open outward. Further, although a spring is used as the elastic body, it may be made of rubber or the like.

The counterweight has the effect of preventing the chuck jaws from opening due to centrifugal force, but it is not necessary if the chuck jaws are small or light, or when the pressing force of the elastic body is high. Although each of the embodiments has two chuck claws, it is also possible to have three or more chuck claws.

In addition, in the second embodiment, the stop position of the chuck body is controlled to avoid interference between the chuck body and the guide rail of the conveyance machine (I'4), but the stop position of the chuck body is controlled to avoid interference between the chuck body and the guide rail of the conveyance machine (I'4). It is also possible to avoid interference with the chuck body.Also, it is not necessary to have such a stop position control section.Depending on the shape of the chuck body and the structure of the transport mechanism, the chuck body may stop at any position. It is not necessary if there is no risk of interference with the transport mechanism.

〔Effect of the invention〕

As explained above, in the present invention, the outer edge of the wafer is supported by chuck claws with the semiconductor wafer separated from the surface of the chuck body, and the wafer is held by pressing the chuck claws with an elastic body. ,
The wafer can be held securely by mechanical elasticity, and since only the outer edge of the wafer contacts, water droplets can be removed from both sides of the wafer.

When an air cylinder is provided and compressed air is sent into the cylinder to move the chuck jaws radially outward, the holding of the wafer can be easily released, improving work efficiency.

When the chuck jaws act as a counterweight, the centrifugal force generated by the counterweight during rotation is enhanced by the centrifugal force generated in the chuck jaws, preventing the chuck jaws from opening outward and preventing the wafer from falling off.

Furthermore, when the stop position of the chuck body is controlled by the stop position control section, the chuck body is stopped so as to face in a fixed direction, thereby avoiding interference with other things such as the transport mechanism.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of a first embodiment of the present invention, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a sectional view showing the structure of a second embodiment of the invention. 4 is a plan view of FIG. 3, and FIG. 5 is a sectional view showing the configuration of a conventional semiconductor wafer support device.
FIG. 6 is a plan view of FIG. 5. 1... Semiconductor wafer, 3... Processing container, 4...
Vacuum tube, 5... Motor, 11... Chuck body, 12a, 12b... Chuck claw, 13a, 13b
. 13c, 13d... counterweight, 14a14b
...Air cylinder, 15a, 15b...Compression spring,
16...Air passage, 17...Metal fittings, 18.
...Desk, one...Air seal, 21a, 21b...
Piston, 31...Disk, 32...Sensor, 33.
...timing belt, 34...electromagnetic clutch, normal motor.

Claims (1)

[Claims] 1. A chuck body; at least two chuck jaws supported by the chuck body so as to move in the radial direction;
The chuck includes an elastic body that presses each of the chuck claws inward in the radial direction, and a chuck body support portion that rotatably supports the chuck body, and the semiconductor wafer is held at a position apart from the surface of the chuck body. A semiconductor wafer holding device characterized in that each of the chuck claws is provided with a recess for supporting an outer edge portion of the semiconductor wafer inside the chuck claw. 2. A chuck body having at least two air cylinders positioned so as to face each other in the radial direction; a piston inserted into each of the air cylinders and moving in the radial direction; a chuck claw fixed to the piston that protrudes from the chuck body; a compressor that feeds compressed air into the air cylinder to press the piston radially outward; and a chuck body. a chuck body support portion that rotatably supports the chuck body, and a recess that supports the outer edge of the semiconductor wafer on the inside of the chuck jaw so that the semiconductor wafer is held at a position apart from the surface of the chuck body. A semiconductor wafer holding device characterized by being provided with each. 3. Each of the chuck claws has a counterweight provided on the opposite side of the rotation center to generate a centrifugal force in a direction different from the centrifugal force generated in the chuck claw due to rotation. The semiconductor wafer holding device as described in 1. 4. a flat plate that rotates together with the chuck body; a sensor unit that is provided on the rotational circumference of the flat plate and detects a predetermined location on the flat plate that is related to the directionality of the chuck body; Claim 1, 2, or 3, further comprising a stop position control unit that stops the chuck body in a fixed direction by rotating the chuck body until a location is detected and then stopping the chuck body. semiconductor wafer holding device.