JP2000332085A - Wafer-clamping apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for external force for chucking a wafer. SOLUTION: This apparatus is composed of a chuck base 6 for mounting a wafer 11 held by holding means and a vertically movable top-opened cup 4 surrounding the chuck base 6. The holding means comprises wafer guides 8 projecting from the chuck base 6 for mounting the wafer 11 and clamp arms 9 each formed at the wafer guide 8 for elastically pressing the wafer 11 to a guide face 8a perpendicular to the chuck base 6 surface, and the clamp arms 9 are rotatably mounted through support pins 10 at the chuck base 6 end and have arm drives 15 projecting at the lower side of the support pins 10 and guide members 16 for rotating the clamp arms 9, by sliding or rolling the arm drives 15 inside the cup 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a wafer clamping device. More specifically, the present invention relates to a wafer clamping apparatus having a wafer chuck for rotating and processing a wafer in a semiconductor manufacturing process.

[0002]

2. Description of the Related Art FIG. 5 is a schematic view of a wafer clamping device. The wafer clamp device 51 includes a cylindrical lower cup 53 mounted on a base 52 and a lower cup 5.
3 is constituted by an upper cup 54 to cover. The upper cup 54 has a cylindrical shape and is formed so that the diameter decreases upward from a predetermined position. The upper cup 54 can be moved up and down by a cylinder 55. Transfer arm 5
The wafer 57 transported in 6 is transported into the upper and lower cups 53 and 54, is chucked by a chuck unit (not shown), is rotated by a motor (not shown), is coated with a chemical by a chemical nozzle 58, and is processed.

FIG. 6 is a diagram showing the structure of a conventional wafer clamping device. Wafer 57 by chemical solution nozzle 58
In the step of applying a chemical solution to the substrate and performing a process, a spin chuck 60 is provided at one end of a motor 59 and a vacuum source 61 is provided at the other end as shown in FIG. The wafer 57 is chucked by the spin chuck 60 and the wafer 57 is evacuated by the vacuum source 61 through the hollow shaft 62 so that the chuck is not detached even when the motor 57 is rotated by the motor 59.

Further, as shown in FIG. 1B, a mechanism for mechanically chucking the outer periphery of the wafer 57 is provided, and a chuck device 63 such as a cylinder is used to prevent the chuck from coming off when the wafer 57 is rotated by the motor 59. The wafer 57 is chucked by external force.

[0005]

However, in the conventional wafer clamping apparatus, when chucking a wafer,
Since an external force such as a vacuum source and a chuck device is required, space and energy other than the processing tank are required, and the entire apparatus is increased in size. These chucking mechanisms are required, thus increasing costs. Further, since the chucking mechanism is complicated, troubles at the time of operation frequently occur.

An object of the present invention is to provide a wafer clamping apparatus which does not require an external force for holding a wafer chuck, in consideration of the above-mentioned prior art.

[0007]

In order to achieve the above object, according to the present invention, there is provided a chuck base for holding and mounting a wafer by holding means, and surrounding the chuck base,
In a wafer clamping device including an upper cup that can be moved up and down with an upper part opened, the holding unit includes a plurality of wafer guides that protrude from a chuck base and mount wafers, and a plurality of wafer guides that are perpendicular to the chuck base surface formed on each wafer guide. A clamp arm that elastically presses the wafer against a guide surface, the clamp arm being rotatably mounted on a chuck base end by a support pin, and projecting an arm drive unit below the support pin. And a guide member for rotating the clamp arm by sliding or rolling the arm drive unit inside the upper cup.

According to this configuration, the wafer is mounted on the wafer guide on the chuck base, and is elastically pressed against the guide surface by the clamp arm to be fixed and held. This clamp arm is driven to rotate by a drive arm projecting below a support pin serving as a pivot axis moving on a guide member on the inner surface of the upper cup, and an arm portion above the support pin performs chuck operation and release of chuck on a wafer. Perform the operation automatically. As a result, the wafer can be chucked according to its own operation without using a vacuum source for applying an external force for chucking the wafer, a mechanical clamp drive mechanism, or the like.

In a preferred embodiment, the chuck base is rotatable, and the wafer guide is provided at a radial position with respect to the center of rotation of the chuck base.

According to this configuration, the wafer is held on the wafer guide provided radially from the center with respect to the rotating chuck base, so that the wafer is stably fixed and held.

In a preferred configuration example, a weight is attached to the arm driving section.

According to this configuration, the rotation of the chuck base causes a centrifugal force to act on the weight below the support pin,
As a result, a force in the direction of pressing the wafer acts on the arm portion above the support pin, and the wafer can be reliably held without using an external force.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view of a wafer clamping device according to the present invention, wherein (A) is a top view,
(B) is a sectional view. As shown, a lower cup 2 is attached to a base 1, and the base 1 is provided with a drainage duct 3 for discharging a chemical solution. An upper cup 4 that can move up and down by a cylinder or the like (not shown) is mounted on the lower cup 2. The upper and lower cups 2 and 4 are formed in a cylindrical shape, and the upper cup 4 is formed so that the diameter decreases from a predetermined position upward. Also, upper and lower cups 2,
The motor 1 is provided on the base 1 so as to be located at the center of the motor 4. The motor 5 and the chuck base 6 provided in the upper cup 4 are connected by a shaft 7, and the motor 5 rotates the chuck base 6.

A wafer guide 8 having an L-shaped cross section for mounting and guiding the wafer 11 on the chuck base 6.
Protrude in a plurality (three in the figure). The wafer guide 8 is, for example, formed by cutting off an inner half of an upper portion of a cylindrical body and forming a guide surface 8a perpendicular to the chuck base surface on the back side. A clamp arm 9 is provided at a position facing the guide surface 8a of the wafer guide 8. The clamp arm 9 is rotatably installed via a support pin 10 provided on the chuck base 6.

An end of a spring 12 is attached to the upper side of the support pin 10 of the clamp arm 9, and the spring 12 is connected to a spring hook 14 attached to the chuck base 6. Due to the elasticity of the spring 12, the wafer 11 placed on the wafer guide 8 is
Is elastically pressed against the guide surface 8a and held.

The lower part of the clamp arm 9 is the chuck base 6
An arm drive unit 15 having a bearing 13 is formed at an end of the arm drive unit 15 so as to be bent outward.
The bearing 13 of the arm drive unit 15 is provided on the inner wall of the upper cup 4.
The arm guide 16 is provided for rotating the clamp arm 9 around the support pin 10 by rolling. A weight 17 is mounted on the arm driving unit 15, and the weight of the weight 17 is adjustable.

FIGS. 2 and 3 are explanatory views showing the rotation of the clamp arm. When the wafer 11 is chucked by the wafer guide 8 and the clamp arm 9, the upper cup 4 is first lowered as shown by an arrow A as shown in FIG. Thereby, the inclined surface 16a of the arm guide 16 descends while pressing the bearing 13, and pushes up the bearing 13 from the inclined surface 16a to the vertical surface 16b. As a result, the clamp arm 9 rotates around the support pin 10 as shown by the arrow B, and the upper end of the clamp arm 9 opens against the force of the spring 12.

In this state, the wafer 11 transferred by a transfer means (not shown) such as a transfer arm is transferred to a predetermined position and mounted on the wafer guide 8. From this state, when the upper cup 4 is raised as shown in FIG. 3 (arrow C), the arm driving unit 15 moves the vertical surface 1 of the arm guide 16.
Rolling along the inclined surface 16a from 6b, and further descending and separating from the arm guide 16, the elasticity of the spring 12 causes the clamp arm 9 to rotate about the support pin 10 as shown by the arrow D, and the wafer 11 is chucked.

In this state, when the chuck base 6 is rotated to process the wafer 11 with a chemical solution, a centrifugal force acts on the clamp arm 9. The centrifugal force can be expressed by F = (W / g) · rω2 (W: weight, g: gravitational acceleration, r: radius, ω: angular velocity). Therefore, assuming that the centrifugal force acting on the clamp arm 9 above the support pin 10 is F2 and the centrifugal force acting below the clamp pin 9 is F3, the clamp arm 9 has a support corresponding to the force of F3-F2 as a whole. A moment around the pin 10 acts.

Therefore, a weight 17 is provided below the clamp arm 9 to increase the weight W, and F3 is made larger than F2, whereby the clamp arm 9 is rotated in the closing direction by centrifugal force to add to the elastic force of the spring 12. Thus, the clamping force of the wafer 11 can be increased.

FIG. 4 is a graph showing the relationship between the clamping force and the rotation speed. A indicates the clamping force, and B indicates the number of rotations. As shown in the figure, the clamping force increases with an increase in the rotation speed. In this case, as can be seen from the above equation of centrifugal force,
Since the clamping force increases in proportion to the square of the number of revolutions, the weight of the weight 17 is adjusted in consideration of this, so that the balance of the clamp arm 9 is maintained appropriately.

When the chemical solution processing is completed, the rotation of the chuck base 6 stops. As a result, the clamping force is
2 only. Thereafter, by lowering the upper cup 4, the clamp arm 9 is opened and the clamp of the wafer 11 is released, as described above with reference to FIG. Instead of the bearing 13 that rolls along the arm guide 16, a curved protrusion that simply slides on the guide surface may be formed.

[0023]

As described above, in the present invention, the wafer is mounted on the wafer guide on the chuck base, and is elastically pressed against the guide surface by the clamp arm to be fixed and held. This clamp arm is driven to rotate by a drive arm projecting below a support pin serving as a pivot axis moving on a guide member on the inner surface of the upper cup, and an arm portion above the support pin performs chuck operation and release of chuck on a wafer. Perform the operation automatically. As a result, the wafer can be chucked according to its own operation without using a vacuum source for applying an external force for chucking the wafer, a mechanical clamp drive mechanism, or the like.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a wafer clamping device according to the present invention, wherein (A) is a top view and (B) is a cross-sectional view.

FIG. 2 is an explanatory view showing rotation of a clamp arm.

FIG. 3 is an explanatory view showing rotation of a clamp arm.

FIG. 4 is a graph showing a relationship between a clamping force and a rotation speed.

FIG. 5 is a schematic diagram of a wafer clamping device.

FIG. 6 is a view showing the structure of a conventional wafer clamping device.

[Explanation of symbols]

1: base, 2: lower cup, 3: drain duct, 4: upper cup, 5: motor, 6: chuck base, 7: shaft, 8: wafer guide, 8a: guide surface, 9: clamp arm, 10: Support pin, 11: wafer, 12: spring, 13: bearing, 14: spring hook, 15: arm drive unit, 16: arm guide, 16
a: inclined surface, 16b: vertical surface, 17: weight.

Claims (3)

[Claims] 1. A wafer clamping apparatus comprising: a chuck base for holding and mounting a wafer by holding means; and a vertically movable upper cup surrounding the chuck base and having an upper opening. A plurality of wafer guides for mounting wafers protruding therefrom, and a clamp arm for elastically pressing the wafer against a guide surface perpendicular to the chuck base surface formed on each wafer guide, wherein the clamp arm is a chuck base At the end, it is rotatably mounted with a support pin, and has an arm drive section protruding below the support pin. The arm drive section slides or rolls inside the upper cup to clamp the arm drive section. A wafer clamping device having a guide member for rotating an arm. 2. The wafer clamping apparatus according to claim 1, wherein said chuck base is rotatable, and said wafer guide is provided at a radial position with respect to a rotation center of said chuck base. 3. The wafer clamping apparatus according to claim 2, wherein a weight is mounted on said arm driving section.