JPH11283957A - Single wafer processing type spin drying device for semiconductor wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably and surely grasp a semiconductor wafer at the center position of a rotating table by a mechanical force. SOLUTION: This single-wafer processing type spin drying device is provided with a rotating cylinder 3 for rotating a table drive, a nozzle shaft 10, shaft elevating mechanisms 17 to 19, a plurality of chucking shafts 14 and a plurality of chucking pawls 16 which respectively have a chucking part, and the device is constituted into a structure, wherein when the shaft 10 is moved upward, the shafts 14 are extended in the outer peripheral direction of a rotating table 2 to rotate the chucking pawls 16, to hold the outer peripheral edge of a semiconductor wafer 1 by the chucking parts provided on the points of the pawls 16, the chucking shafts 14 are pulled in the central direction of the table 2 when the shaft 10 has been lowered to its former position for turning the pawls 16 in the opposite direction, and the grasp of the outer peripheral edge of the wafer 1 by the chucking parts is released.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-wafer spin drying apparatus for a semiconductor wafer, in which a semiconductor wafer is placed on a rotary table and rotated at a high speed to dry the wafer surface.

[0002]

2. Description of the Related Art FIGS. 5 and 6 show a conventional single-wafer spin drying apparatus for semiconductor wafers. In the figure, reference numeral 51 denotes a rotary table on which a semiconductor wafer (hereinafter, abbreviated as “wafer”) W is placed and rotated at a high speed, and 52 is to provide a gap so that the lower surface of the wafer 1 does not contact the surface of the rotary table 51 Are equally spaced along the outer periphery of the wafer 1 placed on the turntable 51 (12 in the figure).
A plurality of chucking mechanisms for gripping wafers arranged at 0 ° intervals).

The chucking mechanism 53 has a claw 53b provided with a wafer gripping portion 53a at its tip.
b is rotatably locked to the outer peripheral portion of the rotary table 51 by a pin 53c at a position near the front end. A spring 53e is interposed between the rear end of the claw 53b and the chucking unit 53d.
Is always urged in a direction away from the outer peripheral edge of the wafer 1.

In the conventional apparatus having the above structure, when the rotary table 51 is rotated by a motor or the like (not shown),
Due to the centrifugal force caused by the rotation, the pawl 53b becomes a leaf spring 53c.
5 rotates in the direction of the arrow (a) in FIG. 5 against the spring force of FIG. The centrifugal force acting on the claw 53b increases as the rotation speed of the turntable 51 increases, and the gripping force of the wafer gripping portion 53a on the wafer 1 increases accordingly. When the rotation speed of the rotary table 51 reaches a predetermined constant speed motion, the wafer gripper 5
3a grips the wafer 1 with a constant force.

On the other hand, when the drying process of the wafer 1 by the high-speed rotation is completed and the rotating table 51 that is rotating at a high speed is gradually stopped, the centrifugal force of the rotating table 51 is gradually reduced as the rotating speed of the rotating table 51 decreases. Claws 53b are getting smaller
Is rotated and returned in the direction of arrow (b) in FIG. 5 by the spring force of the leaf spring 53c. When the rotation of the turntable 51 stops, the wafer gripper 53 at the tip of the claw 53b is stopped.
a is separated from the outer peripheral edge of the wafer 1 and the grip of the wafer 1 is released.

[0006]

As described above, in the conventional single-wafer spin drying apparatus, a chucking mechanism utilizing centrifugal force generated by high-speed rotation of the rotary table 51 has been used. However, the chucking mechanism using the centrifugal force has the following problems.

(1) The gripping of the wafer 1 by the claws 53b at the time of rising from the start of rotation of the rotary table 51 to reaching a certain speed, and at the time of falling until the rotary table 51 stops from the certain speed. The force changes as the centrifugal force changes and is not constant. For this reason,
A rotation speed shift occurs between the wafer 1 and the rotary table 51, and a slip occurs between the lower surface of the wafer 1 and the wafer receiving portion 52 of the rotary table 51, and particles (contaminant fine particles) are generated. In some cases, a sufficient cleaning effect was not obtained.

(2) It is necessary to arrange a plurality of chucking mechanisms (three in the illustrated example) along the outer periphery of the wafer 1, but the individual chucking mechanisms are separately provided when centrifugal force is applied. It is supposed to work. For this reason, when the rotary table 51 rotates, the wafer 1 is gripped in one direction due to a difference in operation timing of each chucking mechanism, and the axis of the rotary table 51 and the center of the wafer 1 are aligned. There is a possibility that the shaft may be rotated while being shifted or eccentric. When rotated in such an eccentric state,
In addition to causing vibration, in the worst case, the vibration may damage the wafer.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide a single-wafer type semiconductor wafer which can stably and reliably hold a wafer at a center position of a rotary table by mechanical force. An object of the present invention is to provide a spin dryer.

[0010]

In order to achieve the above object, the present invention provides a single-wafer spin drying of a semiconductor wafer in which a semiconductor wafer is placed on a rotary table and rotated at a high speed to dry the wafer surface. In the device, a rotary cylinder connected to the center of the lower surface of the rotary table to drive the rotary table to rotate, and coaxially inserted into the rotary cylinder,
A nozzle shaft that rotates together with the rotating cylinder and is movable vertically in the rotating cylinder, a shaft elevating mechanism that moves the nozzle shaft vertically, and a center located on the rotary table. A plurality of chucking shafts which are radially arranged from the position toward the outer peripheral direction and whose base ends are connected to the distal end of the nozzle shaft by a link; and a vertical surface which is located near the outer peripheral edge of the semiconductor wafer. The rotatable support is rotatably supported on a rotary table so that the tip of the chucking shaft is connected to one end of the rotary table and the outer edge of the semiconductor wafer is connected to the other end. A plurality of chucking claws formed with a chucking portion to be gripped, and when the nozzle shaft is moved upward, the chucking shaft is turned on a rotary table. The chucking claw is extended in the outer peripheral direction, and the chucking claw at the tip grips the outer peripheral edge of the semiconductor wafer. When the nozzle shaft is lowered to the original position, the chucking shaft is rotated. The chucking claw is rotated in the opposite direction by retracting the chucking claw in the opposite direction to release the gripping of the semiconductor wafer by the chucking portion.

[0011]

When the nozzle shaft is moved upward by the shaft elevating mechanism, the chucking shaft extends in the outer circumferential direction of the rotary table. As a result, the chucking claw rotates, and the chucking portion formed at the tip of the chucking abuts on the outer peripheral edge of the semiconductor wafer to grip the semiconductor wafer. Further, when the drying process is completed and the rotation of the rotary table is stopped, when the nozzle shaft is moved downward and lowered to the original position, the chucking shaft is retracted toward the center of the rotary table, and the chucking claw is moved. Is rotated in the direction opposite to that at the time of gripping. Thereby, the grip of the outer peripheral edge of the semiconductor wafer by the chucking unit is released.

As described above, according to the present invention, the semiconductor wafer is held in a fixed position by mechanical force before the rotation of the rotary table is started, and the grip of the semiconductor wafer is released when the rotary table stops. ing. For this reason, it is possible to eliminate a position shift or a rotation shift of the semiconductor wafer due to a change in the centrifugal force as in the conventional apparatus, thereby preventing generation of particles.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a single wafer spin drying apparatus for a semiconductor wafer according to the present invention will be described below with reference to FIG.
This will be described with reference to FIGS. In the figure, reference numeral 1 denotes a semiconductor wafer to be dried (hereinafter abbreviated as “wafer”), and 2 denotes a rotary table on which the wafer 1 is mounted. A rotating cylinder 3 that is driven to rotate is fixed. A fixed cylinder 5 is disposed on the outer periphery of the rotating cylinder 3 via a bearing 4, and the fixed cylinder 5 is attached to an upper base 6.

A pulley 7 is fixedly mounted on the outer periphery of the lower part of the rotary cylinder 3. The rotary cylinder 3 is rotated integrally with the rotary table 2 by being driven to rotate by a motor (not shown). ing. A hollow nozzle shaft 10 is disposed inside the rotary cylinder 3 via a bearing 8 and a spline 9, and the nozzle shaft 10 can move up and down in the rotary cylinder 3. A diaphragm plate 12 having a nozzle port 12a is attached to an upper portion of the nozzle shaft 10 via a drive block 11. Although not described in detail, the detailed description is omitted, but an inert compressed gas (eg, N ₂ gas) for drying the wafer is supplied from a supply tank (not shown) into the hollow portion of the nozzle shaft 10. The liquid is injected from the nozzle port 12a of the diaphragm plate 12 toward the lower surface of the wafer.

A plurality of (three in the illustrated example) chucking shafts 1 are connected to the drive block 11 via a link 13.
Numerals 4 are radially attached at equal intervals (120 degrees in the illustrated example) from the center side toward the outer periphery. Each of the distal ends extends through the bearing 15 to the outer peripheral position of the rotary table 2, and a chucking claw 16 having a link structure is rotatably attached to the distal end.

The nozzle shaft 10 has a spline 9
Through the bearing 13
Through the block 18. The block 18 is attached to a linear guide 19 that constitutes a mechanism for elevating the nozzle shaft 10, and
0 is rotatable in the block 18 and
It is arranged so as to be vertically movable by a linear guide 19 via a block 18.

The chucking claw 16 is positioned near the outer peripheral edge of the wafer 1 and pivots in a vertical plane.
a is rotatably supported on the turntable 2 by one end of the chucking shaft 14.
Of the wafer 1 is rotatably locked by a pin 16b, and the other end has a V-shaped chucking portion 16c for abutting against and gripping the outer peripheral edge of the wafer 1.
And an arc-shaped slope portion 16d following the chucking portion 16c is formed.
Grips the outer peripheral edge of the wafer 1.

Next, the operation of the apparatus of the present invention having the above configuration will be described. When the block 18 is pushed upward by the linear guide 19, the block 1 is moved up and down.
And the nozzle shaft 10 in a fixed state rises. At this time, the nozzle shaft 10 is engaged with the rotary cylinder 3 by the spline 9 and rises without rotating. This lifting operation is guided by the bearing 4.

When the nozzle shaft 10 rises, the drive block 11 also rises upward as indicated by an arrow (c) (see FIG. 3). When the drive block 11 rises, the link 13 attached to the drive block 11 rotates (see FIG. 4) and extends toward the outer periphery of the turntable 2 indicated by the arrow (d). A chucking shaft 14 is attached to the link 13. Therefore, when the link 13 extends toward the outer periphery of the turntable 2, the chucking shaft 14 also extends through the bearing 15 toward the outer periphery of the turntable 2 indicated by the arrow (d).

When the chucking shaft 14 extends in the direction of the arrow (d), the chucking claw 16 to which the tip of the chunking shaft 14 is connected has the pin 16a as a fulcrum and is indicated by an arrow (e) (see FIG. 4). Rotate in the direction. Then, the V-shaped chucking portion 1 of the chucking claw 16
6c hits the outer peripheral edge of the wafer 1 which is transported by the robot arm (not shown) to the mounting position and stands by, and chucks the wafer 1 at the position.

Next, when the pulley 7 is rotationally driven by a motor or the like (not shown), the rotary cylinder 3 to which the pulley 7 is attached rotates while being supported by the bearing 4 in the fixed cylinder 5. When the rotary cylinder 3 rotates, the rotary table 2 attached to the rotary cylinder 3 rotates, and the wafer 1 held by the chucking claw 16 on the rotary table 2 also rotates, and the drying process starts. Is done.
The nozzle shaft 10 is meshed with the rotary cylinder 3 by a spline 9, and rotates in synchronization with the rotary table 2. The rotation of the nozzle shaft 10 is guided by a bearing 8 in the rotary cylinder 3.

When the rotary table 2 is rotated at a high speed and the drying process of the wafer 1 is completed after a predetermined period of time, the rotation of the rotary table 2 is stopped, and then the nozzle shaft 10 is pushed down by the linear guide 19. . When the nozzle shaft 10 descends, the drive block 11 also descends, and the link 13 attached to the drive block 11
Rotates. Thereby, the chunking shaft 14
Is retracted toward the center of the turntable 2, and the chucking claw 16 is rotated by an arrow (f) with the pin 16a as a fulcrum.
(See FIG. 4). Therefore, the chucking portion 16 of the chucking claw 16 has been used until then.
The wafer 1 held by c is disengaged from the chucking section 16c, slides down along the slope section 16d that follows, and moves onto a waiting robot arm (not shown) as indicated by an arrow (g). It moves and is carried out of the device.

As described above, in the case of the present invention, the drive block 11 is attached to the tip of the nozzle shaft 10 that can rotate and move up and down, and the tip of the chuck shaft 14 is chucked via the drive block 11 and the link 13. The pawl 16 is rotated by a mechanical force, and the wafer 1 can be firmly held with a uniform force by the three chucking pawls 16 provided at three places around. For this reason, there is no occurrence of a difference in rotational speed between the wafer 1 and the rotary table 2 unlike the conventional apparatus, and it is possible to eliminate the generation of particles due to slippage. Also, the chucking claws 16
Only contacts the outer peripheral edge of the wafer 1, so that the lower surface of the wafer can be reliably cleaned and dried.

[0024]

As described above, according to the single-wafer spin drying apparatus for a semiconductor wafer according to the present invention, when the rotation of the rotary table is started, which has been a problem with the conventional centrifugal chucking mechanism. It is possible to eliminate a rotational speed shift and a positional shift between the wafer and the rotary table due to a decrease in the gripping force immediately before the rotation stops, and to reliably prevent generation of particles due to rubbing or the like and damage due to wafer vibration.

Since the chucking claws for gripping the wafer abut almost in point contact with the outer peripheral corners of the wafer, the peripheral surface of the wafer is not obstructed by the jig.
A sufficient drying effect can be obtained even on the peripheral surface of the wafer.

As a result, the yield of products can be significantly improved, and the reliability of the device can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a schematic vertical sectional view showing an embodiment of a single wafer type spin sensor apparatus for a semiconductor wafer according to the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is an enlarged sectional view of a nozzle shaft and a drive block in FIG. 1;

FIG. 4 is a schematic enlarged side view of a chucking claw in FIG. 1;

FIG. 5 is a schematic vertical sectional view of a conventional device.

FIG. 6 is a plan view of FIG. 5;

[Explanation of symbols]

 Reference Signs List 1 semiconductor wafer 2 rotating table 3 rotating cylinder 4 bearing 5 fixed cylinder 6 upper base 7 pulley 8 bearing 9 spline 10 nozzle shaft 11 drive block 12 diaphragm plate 13 link 14 chucking shaft 15 bearing 16 chucking claw 16a pin 16b pin 16c chuck King part 16d Slope part 18 Block 19 Linear guide

Claims (1)

[Claims] 1. A single-wafer spin drying apparatus for a semiconductor wafer wherein a semiconductor wafer is placed on a rotary table and rotated at a high speed to dry the wafer surface. A rotary cylinder that rotationally drives the table, a nozzle shaft that is coaxially inserted into the rotary cylinder, rotates together with the rotary cylinder, and is movable vertically in the rotary cylinder; A shaft elevating mechanism that moves in the vertical direction; a plurality of shaft elevating mechanisms that are located on the rotary table and radially arranged from a center position toward an outer peripheral direction, and whose base end is connected to the tip of the nozzle shaft by a link. A chucking shaft, which is rotatably supported on a rotary table so as to rotate in a vertical plane near an outer peripheral edge of the semiconductor wafer; A tip of the chucking shaft is connected to one end, and a plurality of chucking claws formed with a chucking portion for gripping an outer peripheral edge of the semiconductor wafer are provided at the other end. When the nozzle shaft is moved upward, the chucking shaft extends in the outer peripheral direction of the turntable to rotate the chucking claw, and the outer peripheral edge of the semiconductor wafer is gripped by the chucking portion at the tip, and the nozzle is When the shaft is lowered to its original position, the chucking shaft retracts in the direction of the center of the turntable, rotates the chucking claw in the opposite direction, and releases the gripping of the semiconductor wafer by the chucking portion. Characteristic single wafer spin dryer for semiconductor wafers.