JPH11354615A - Semiconductor wafer chuck device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor wafer chuck device, which can perform mounting and dismounting of a semiconductor wafer on a stage surface of a susceptor and transfer thereof to an automatic transfer arm or the like efficiently and stably. SOLUTION: Three top-shaped members 20, each having a tapered recess 21 therein are disposed around a wafer-mounting position 1' of a susceptor 10 to be supported by a push rod 22. A lower end of the push rod 22 is inserted into a cylindrical spring case 24 containing a coil spring 23, and a lower end of the case 24 is fixed to a support plate 25. A welder bellows 27 is provided between the support plate 25 and a periphery of a round hole 12 made in the lower surface of a stage 11 to air tightly seal the bellows inside (vacuum) and outside (atmospheric pressure) thereof. The support plate 25 is fixed on to a support base 26, in such a manner that the support base 26 can be moved vertically by primary and secondary air cylinders 28 and 29 which are provided vertically in two stages and can be moved in a radial direction of the susceptor by a horizontal moving means, including a rotary plate 32 and a linking rod 33. The top member 20 is moved vertically and moved horizontally via the support base 26 or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer chucking device, and more particularly to a susceptor provided in a susceptor in a plasma processing apparatus for a semiconductor wafer for performing a plasma etching, a plasma CDV, etc. in a semiconductor manufacturing process. The present invention also relates to a semiconductor wafer chuck device for performing attachment / detachment to an upper surface of a susceptor and delivery to an automatic transfer arm or the like.

[0002]

2. Description of the Related Art In an apparatus for performing plasma processing such as plasma etching on the surface of a semiconductor wafer, a wafer stage on which the wafer is mounted is placed on a susceptor set on the upper surface (stage surface). In order to remove thermal adverse effects, a cooling system for cooling the wafer is additionally provided, and in order to improve the cooling efficiency of the wafer, an electrostatic chuck system in which the wafer is brought into close contact with the stage surface by electrostatic force is generally adopted. I have. The outside of the susceptor is evacuated to perform plasma processing, while the inside of the susceptor is maintained at atmospheric pressure to smoothly operate the cooling system, the mechanism of the electrostatic chuck, and other necessary mechanisms. Therefore, the operation of removing and raising the processed semiconductor wafer from the stage surface and transferring it to the automatic transfer arm, or receiving the wafer from the automatic transfer arm before processing and mounting the wafer on the stage surface is performed in a vacuum. If the mechanism for performing the above is disposed in a vacuum outside the susceptor, the mechanism that can be used is significantly limited,
Conventionally, the wafer is moved up and down by three or four lift-up pins that are moved up and down from inside the susceptor.

[0003]

However, with the lift-up pin, it is necessary to wait for the operation until the electrostatic force on the stage surface does not completely contribute to the close contact of the wafer.
Otherwise, the attachment / detachment to the stage surface and the delivery to the automatic transfer arm are inefficient and unstable due to, for example, the wafer on the pin being tilted, falling or being damaged, or being displaced from the predetermined transfer position to the automatic transfer arm. Had become something.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a semiconductor device capable of efficiently and stably transferring a semiconductor wafer to a stage surface of a susceptor and transferring the semiconductor wafer to an automatic transfer arm. An object of the present invention is to provide a wafer chuck device.

[0005]

SUMMARY OF THE INVENTION A semiconductor wafer chucking device according to the present invention is attached to a susceptor for chucking a semiconductor wafer in a vacuum, attaching and detaching the semiconductor wafer to an upper surface of a susceptor, and transferring the semiconductor wafer to an automatic transfer means. An apparatus, comprising: at least three piece members having a tapered recess for receiving a peripheral edge of the semiconductor wafer; lifting means for lifting and lowering the piece member; and horizontally moving the piece member in a diameter direction of the susceptor. It is characterized by comprising a horizontal moving means and a separation resistance absorbing means for absorbing separation resistance of the semiconductor wafer with respect to the upper surface of the susceptor.

That is, in the present invention, at least three piece members are moved in the vertical direction and the susceptor radial direction by the elevating means and the horizontal moving means, so that the peripheral edge of the semiconductor wafer is received in the recess of the piece member and the wafer is received. By chucking the wafer at three points on the periphery or releasing the chuck of the wafer by such a piece member, the wafer can be attached to and detached from the upper surface (stage surface) of the susceptor and can be transferred to an automatic transfer means such as an automatic transfer arm. Therefore, unlike the conventional simple lifting of the wafer by the lift-up pins, the wafer can be reliably chucked by the concave portion of the bridge member, and when the concave portion receives the wafer periphery, the height of the concave portion and the wafer is reduced. Even if there is a slight shift, the shift can be absorbed by the tapered recess.

[0007] As the elevating means, the first height position where the concave portion of the piece member is at the same height as the wafer on the stage surface, and the second height position where the wafer is transferred between the automatic transfer arm and the like. Any member can be used as long as the piece member can be moved up and down between them. Specifically, a cylinder unit or the like, particularly an air cylinder unit, can be preferably used.

The first and second moving means are horizontal moving means.
At the height position, the piece member is moved in and out of the stage radial direction to receive the wafer periphery in the concave portion of the piece member,
As long as the peripheral edge of the wafer can be released from the concave portion, for example, a cylinder unit or the like can be attached to each piece member, but each piece member is simultaneously moved by a driving source such as a single cylinder unit. It is desirable to be able to do this, and the specific configuration will be described later in the section of the embodiment of the invention.

In the present invention, when the piece member chucking the wafer is lifted and the wafer is detached and raised from the stage surface, the electrostatic force remaining on the stage surface prevents the wafer from being separated and raised, and the lifting means Resistance to the rise of the bridge member due to the force
Even if works, the detachment resistance is absorbed by the detachment resistance absorbing means, so that the breakage of the wafer which may occur when the wafer is forcibly detached can be reliably prevented.

As the separation resistance absorbing means, a spring or the like can be preferably used.

The semiconductor wafer chuck device according to the present invention may include a sealing member that partitions the vacuum side and the atmospheric pressure side inside the susceptor in an airtight manner and that can be flexibly deformed.

That is, while the piece member needs to be placed in a vacuum in order to elevate and lower above the susceptor, the elevating means and the horizontal moving means are disposed at the atmospheric pressure in the susceptor. It is necessary to hermetically seal the means and the horizontal moving means side, and this seal must not prevent the lifting / lowering means and the horizontal moving means outside the seal from driving the piece member inside the seal. It is necessary to smoothly transmit a required operation through the intermediary. From such a viewpoint, a flexible member is selected as the seal member, and a preferable specific example thereof includes a welding bellows.

[0013]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an explanatory plan view schematically showing a part of a plane of a susceptor 10 in an etcher for performing a plasma etching process on a surface of a semiconductor wafer 1 (see FIG. 2). FIG. 2 is a sectional explanatory view schematically showing a section.
Shown in The upper surface of the susceptor 10 is defined as a wafer stage 11 in which the back surface of the semiconductor wafer 1 is brought into close contact by an electrostatic chuck method during an etching process, and a predetermined wafer mounting position 1 ′ on the stage surface 11 ′ is indicated by a dashed line in FIG. .

The wafer mounting position 1 'on the susceptor 10
In order to chuck the semiconductor wafer 1 from three points on the periphery of the wafer 1, three piece members 20 having a circular horizontal cross section are disposed around the periphery of the wafer 1 at intervals of 120 degrees. Tapered (triangular) recess 21 for receiving the periphery
Having. On the other hand, the wafer stage 11 is set so as to be lowered from the step on the outer peripheral portion of the wafer mounting position 1 ′, and to float the peripheral edge of the wafer 1 at the mounting position 1 ′ from the stage surface 11 ′ to be received by the concave portion 21 of the piece member 20. .

A round hole 12 having a larger diameter than the piece member 20 is formed in a portion of the wafer stage 11 corresponding to the piece member 20. The piece member 20 is supported by the push rod 22, and in the standby state (initial state) shown in FIG. 2, the lower half thereof is inside the round hole 12 and the center is slightly shifted from the center of the round hole to the outside in the diameter direction of the susceptor 10. Is located. The lower end portion of the push rod 22 whose diameter is increased enters into a cylindrical spring case 24 accommodating a cholill spring 23 as a detachment resistance absorbing means, and the spring case 2
The lower end of 4 is fixed concentrically to a disk-shaped support plate 25. Between the support plate 25 and the periphery of the round hole 12 on the lower surface of the stage 11, a welding bellows 27 having a substantially cylindrical bellows is interposed, and the welding bellows 27 is located above the susceptor 10 and the vacuum side inside the bellows 27 and the bellows 27. The outside susceptor 10 and the atmospheric pressure side are air-tightly sealed and partitioned, and the bellows allow flexible deformation.

The support plate 25 is fixed to a support base 26 (see FIG. 1). The support base 26 is provided with two primary air cylinders 28 and secondary air cylinders 29 vertically arranged as lifting means (both for convenience). Are represented by arrows), and can be moved in and out of the susceptor radial direction by the horizontal moving means 30 (see FIG. 1). The support 26 is moved in the susceptor radial direction by guiding rollers (not shown) attached to the support 26 to rails (not shown).

The horizontal moving means 30 is rotatably mounted concentrically with the air cylinder 31 serving as a single driving source and the susceptor 10, and rotates forward and backward by expansion and contraction of a rod 31 'of the air cylinder 31. The plate 32, the rotation plate 32 and the respective support bases 26 are respectively pin-connected to the rotation plate 32 and the support base 2.
And a connecting rod 33 for connecting between the air cylinders 31. When the rod 31 'of the air cylinder 31 is extended, the rotating plate 32
Is rotated clockwise, and the support base 2 is connected via the connecting rod 33.
When the cylinder rod 31 ′ is contracted while the cylinder 6 is pulled inward in the susceptor radial direction, the rotating plate 32 rotates counterclockwise, and the support 26 is pushed back outward in the susceptor radial direction via the connecting rod 33. it can.

Next, the semiconductor wafer 1 after the etching process
A series of operations from detaching and rising from the stage surface 11 ′ and transferring it to an automatic transfer arm (not shown) will be described.

First, the primary air cylinder 28 is extended from the standby state shown in FIG. 2 by a predetermined first-stage height. As shown in FIG. 3, with the extension, the piece member 20 is raised through the support base 26, the support plate 25, the spring case 24, the spring 23, and the push rod 22 at predetermined heights. 11 to a first height position that is the same as the height of the wafer 1.

Next, the rod 31 'of the air cylinder 31
Is extended by a predetermined length set in advance,
The support 26 is pulled inward in the radial direction of the susceptor by a predetermined length through the rotation of the rotation plate 32 at a predetermined angle and the predetermined operation of the connecting rod 33. As a result, the piece member 20 is attached to the support plate 2.
5, through the horizontal movement of the spring case 24 and the push rod 22 by a predetermined length, as shown in FIG.
The wafer 1 is horizontally moved to a position for receiving the wafer periphery, and the wafer 1 is chucked by three piece members 20. At this time, even if the height between the concave portion 21 and the wafer 1 is slightly shifted,
The error can be absorbed by the tapered recess 21. Further, the welding bellows 27 is deformed obliquely so to speak, but the horizontal of the support base 26 and the support plate 25 and the vertical of the spring case 24 and the push rod 22 are maintained.

Next, the secondary air cylinder 29 is extended by a predetermined second stage height, the wafer 1 is separated from the stage surface 11 'and raised, and the piece member 20 is moved to the automatic transfer arm. Up to the second height position to be delivered to. Subsequent delivery to the automatic transfer arm is performed by horizontally moving the piece member 20 outward in the susceptor radial direction by contraction of the cylinder rod 31 '.

The operation of receiving the wafer 1 from the automatic transfer arm and placing it on the stage surface 11 'reverses the above operation.

When the wafer 1 is separated from the stage surface 11 'and lifted, if the electrostatic force remaining on the stage surface 11' causes resistance to the separation of the wafer 1, as shown in FIG. Is coil spring 23
To act to absorb the resistance,
For example, even if the residual electrostatic force is relatively weak and the wafer 1 is lifted, the wafer 1 is stably held by the chuck of the bridge member 3. Therefore, it is possible to surely prevent the wafer 1 from being damaged when the wafer 1 is forcibly detached or lifted up in an unstable manner.

[0025]

As described above, in the semiconductor wafer chucking apparatus according to the present invention, the semiconductor wafer is reliably chucked from the peripheral edge of the wafer by at least three pieces having tapered recesses, and the required pressure in vacuum is maintained. Automatic transfer can be performed, and when the wafer edge is received by the piece member, even if the height between the concave portion and the wafer is slightly shifted,
The deviation can be absorbed by the tapered recess.

When the wafer is detached and raised from the upper surface of the susceptor, if the detachment resistance is received by the electrostatic force remaining on the upper surface of the susceptor, the resistance can be absorbed by the detachment resistance absorbing means. It is possible to prevent the wafer from being damaged or the like.

[Brief description of the drawings]

FIG. 1 is an explanatory plan view schematically showing a plane of a susceptor by partially seeing through the plane;

FIG. 2 is an explanatory cross-sectional view schematically showing a stand-by state of a piece member taken along the line AA in FIG. 1;

FIG. 3 is an explanatory sectional view showing a state in which a piece member is raised by a first stage from a standby state of FIG. 2;

FIG. 4 is an explanatory sectional view showing a state in which the bridge member is moved inward in the susceptor radial direction from the state of FIG.

FIG. 5 is an explanatory cross-sectional view showing a state in which the bridge member is raised in a second stage from the state of FIG. 4;

FIG. 6 is an explanatory cross-sectional view showing a state in which separation resistance when the piece member is raised in the second stage from the state of FIG. 4 is absorbed.

[Explanation of symbols]

 Reference Signs List 1 semiconductor wafer 1 'wafer mounting position 10 susceptor 11 wafer stage 11' stage surface 12 round hole 20 piece member 21 recess 22 push rod 23 coil spring 24 coil case 25 support plate 26 support base 27 welding bellows 28 primary air cylinder 29 2 Next air cylinder 30 Horizontal moving means 31 Air cylinder 32 Rotating plate 33 Connecting rod

Claims (2)

[Claims] 1. An apparatus attached to a susceptor for chucking a semiconductor wafer in a vacuum and attaching and detaching the semiconductor wafer to and from an upper surface of the susceptor and transferring the semiconductor wafer to an automatic transfer means.
At least three piece members having a tapered recess for receiving the periphery of the semiconductor wafer, elevating means for elevating the piece member, and horizontal moving means for horizontally moving the piece member in the diameter direction of the susceptor; A chucking device for a semiconductor wafer, comprising: separation resistance absorbing means for absorbing separation resistance of the semiconductor wafer with respect to the upper surface of the susceptor. 2. The semiconductor wafer chucking device according to claim 1, further comprising a sealing member that partitions the vacuum side and the atmospheric pressure side inside the susceptor in an airtight manner and that can be flexibly deformed.