JPH09181151A - Substrate position alignment equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a position alignment equipment capable of aligning a substrate to a reference surface, without being affected by irregularity of the outer diameter of a substrate. SOLUTION: A first fixing guide 1 and a second fixing guide 3 are fixed to a fixing shaft 4, and a rotary guide 2 is arranged between the guides 1 and 3, pivotally to the fixing shaft 4. In the first and the second guides 1, 3, first long holes 11, 13 stretching in the radial direction are formed. In the rotary guide 2, a second long hole 12 stretching in the direction inclined in the radial direction is formed. When the rotary guide 2 is pivoted at the time of position alignment, an abutting pin 8 is pushed by the second long hole 12, moved in the direction of a reference axis Q, along the first long hole 11, and abuts against the outer peripheral end surface of the substrate. Thereby the substrate is moved to the reference position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate alignment apparatus for aligning a position of a substrate transferred to a substrate processing apparatus for performing a predetermined process on a substrate such as a semiconductor wafer with a predetermined reference position.

[0002]

2. Description of the Related Art In a substrate processing apparatus having a plurality of processing units, for example, after aligning a central position of a substrate taken out from a substrate storage cassette with a predetermined reference position,
It is configured to be transported to each processing unit. As a result, the position of the substrate transferred to each processing unit is always constant, and it is possible to suppress variations in processing for each substrate.

A substrate alignment device is used for aligning the substrate. FIG. 6 is a configuration diagram of a conventional substrate alignment apparatus, (a) is a plan view,
(B) is a front view. The substrate 15 has a plurality of support pins 34.
Horizontally supported by A pair of substrate matching members 31 and 32 are provided on both sides of the substrate 15. A plurality of contact pins 33 are formed on the upper surfaces of the board matching members 31 and 32. The pair of substrate matching members 31 and 32 is the substrate 1
It is provided so as to be able to move forward and backward with respect to 5.

In FIG. 6, a vertical line (central axis) passing through the center of the substrate 15 is indicated by P, and a reference axis on which the central axis P of the substrate should be located is indicated by Q. When the substrate 15 is sent to the substrate alignment device 30 and is supported by the support pins 34, the central axis P of the substrate 15 may be slightly deviated from the reference axis Q. When the pair of substrate matching members 31 and 32 move forward with respect to the substrate 15, the contact pins 33 come into contact with the outer peripheral end surface of the substrate 15 and move the substrate 15 in the horizontal direction to align the substrates.

The substrate alignment members 31, 32 are formed so that the central axis P of the substrate 15 coincides with the reference axis Q at the most advanced position. Therefore, the substrate matching members 31, 32
The central axis P of the substrate 15 coincides with the reference axis Q at the position where the forward movement is stopped.

[0006]

Usually, a substrate (wafer) is used.
A tolerance is defined for the diameter of the substrate, and variations in the diameter of each substrate are allowed within the tolerance. For example, in the case of an 8-inch wafer, it is ± 0.5 m for a diameter of 200 mm.
A tolerance of m is set. Therefore, as shown in FIG. 7, the distance Wb between the pair of contact pins 33, 33 facing each other in a state where the pair of substrate matching members 31, 32 is advanced is (substrate diameter + positive tolerance). It is set.

Therefore, when the diameter Wa of the substrate 15 is smaller than the distance Wb between the contact pins, the substrate 15 is moved in the horizontal direction only by the contact pins 33 of the one substrate matching member 31, and the other substrate is aligned. The horizontal movement of the substrate 15 is stopped before contacting the contact pin 33 of the member 32. Therefore, the central axis P of the substrate 15 and the reference axis Q do not completely coincide with each other, and the alignment of the substrate 15 ends with the central axis P of the substrate 15 deviated from the reference axis Q by the distance d. This substrate 1
When 5 is supplied to, for example, a rotary coating apparatus, the substrate 15 is held at a position eccentric from the center of rotation by a distance d, and rotation processing is performed. For this reason, the spin coating characteristics may be deteriorated such as the width of the edge cleaning being shifted.

Further, when a substrate having a substrate diameter exceeding the tolerance is fed into the substrate aligning device, all the contact pins 33 are moved before the substrate aligning members 31, 32 reach a predetermined forward position. The contact pin 3 which is in contact with the outer peripheral end surface of 15 and receives the forward drive force of the substrate matching members 31 and 32.
3 presses the outer peripheral end surface of the substrate 15. Since the contact pin 33 is made of resin, an appropriate pressing force is applied to the contact pin 33.
It is absorbed by its own elastic deformation. However, if the elastic force varies among the plurality of contact pins 33, the substrate 15 is pushed toward the contact pin 33 side having a large elastic force, which causes the displacement of the substrate 15.

Further, when the pair of substrate matching members 31, 32 are forcibly moved forward with respect to the substrate 15 whose diameter greatly exceeds the tolerance range, the contact pin 3 is moved.
3 beyond the limit of elastic deformation, the contact pin 33 to the substrate 15
There is a problem that an excessive pressing force acts on the substrate 15 to damage the substrate 15.

Thus, the conventional substrate alignment apparatus 3
0 is configured to preliminarily assume the diameter dimension of the substrate, determine the forward movement position of the pair of substrate matching members 31, 32 based on this, and perform the substrate alignment within this range.
Therefore, if the actual substrate diameter is significantly different from the expected substrate diameter, a positioning error may occur,
There is a problem that the substrate is damaged.

On the other hand, as disclosed in Japanese Patent Laid-Open No. 1-269256 and Japanese Utility Model Laid-Open No. 5-13037, a method of recognizing the shape of each substrate by using image recognition technology and performing alignment is also proposed. There is. However, such a method has a problem that the apparatus becomes complicated and expensive, the calculation processing for image recognition takes time, and rapid processing is difficult.

An object of the present invention is to provide a substrate alignment apparatus capable of aligning a substrate at a reference position without being affected by variations in substrate outer diameter.

[0013]

In the substrate alignment apparatus according to the first aspect of the invention, the substrate is horizontally moved so that the central axis of the horizontally supported substrate coincides with a predetermined reference axis. A substrate alignment device for aligning substrates by means of at least three abutment pins distributedly arranged on the circumference of a circle centered on a reference axis and movably guided in the radial direction of the circle. And a contact pin driving means that moves at least three contact pins toward the reference axis by equal distances to contact the outer peripheral end surface of the substrate.

In the present specification, the "central axis of the substrate" is intended to mean a straight line which passes through the central point of the surface of the substrate which is supported horizontally and extends in the vertical direction. A substrate alignment apparatus according to a second aspect of the present invention is the substrate alignment apparatus according to the first aspect of the present invention, wherein the contact pin driving means has at least three contact pins inserted therein and extends in the radial direction. A first guide member having three first elongated holes, and at least three second elongated holes into which at least three contact pins are inserted and which extend in a direction inclined with respect to the radial direction of the circle. A second guide member having
The second guide member is provided with rotating means for rotating the second guide member with respect to the first guide member about the reference axis.

The substrate alignment apparatus according to the third invention is
In the configuration of the substrate alignment apparatus according to the first or second aspect of the invention, the rotating means includes a rotating force applying means for applying a rotating force to the second guide member, and a rotating force applied to the second guide member. Is provided with a restricting means for restricting the value so as not to exceed a predetermined value.

The substrate alignment apparatus according to the fourth invention is
In the configuration of the substrate alignment apparatus according to the first to third inventions, the second guide member is a disc-shaped member,
The guide member is composed of two plate-shaped members arranged above and below the disc-shaped member.

The substrate alignment apparatus according to the fifth invention is
In the configuration of the substrate alignment apparatus according to the second to fourth inventions, further, bearings are respectively provided at positions penetrating the first elongated hole and the second elongated hole on the outer peripheral surface of the contact pin. I am trying.

In the substrate alignment apparatus according to the first to fifth aspects of the invention, at least three abutment pins abut on the outer peripheral end face of the substrate and move. The contact pin moves the substrate in the horizontal direction, and the alignment is performed so that the central axis of the substrate coincides with a predetermined reference axis. Moreover, all of the plurality of contact pins move equidistantly in the predetermined reference axis direction, so that the central axis of the substrate is aligned with the predetermined reference axis. As a result, the alignment can be performed so that the central axis of the substrate is surely aligned with the predetermined reference axis without being affected by the variation in the outer diameter of the substrate.

Particularly, in the substrate alignment apparatus according to the second aspect of the present invention, the contact force is applied to the contact pin by rotating the second guide member having the second elongated hole, and the first contact member is pressed. The contact pin is configured to move in the radial direction along the long hole. Therefore, the plurality of contact pins can be simultaneously and uniformly moved by one operation of rotating the second guide member, and the positioning operation of the substrate can be accurately performed with a simple configuration. .

Particularly, in the substrate aligning device according to the third aspect of the invention, the rotating means is provided with the regulating means so that the rotational force applied to the second guide member is controlled so as not to exceed a predetermined value. Therefore, it is possible to prevent the inconvenience that the contact pin excessively presses the contact surface of the substrate and damages it by applying an excessive rotational force.

Further, in the board aligning apparatus according to the fourth aspect of the invention, the two first guide members for guiding the movement of the contact pins are arranged in the vertical direction, so that the contact pins are arranged in the vertical direction. Since the contact pin is supported at a position, the contact pin can be stably moved in the direction of contacting the substrate while maintaining the posture in the vertical direction.

Particularly, in the substrate aligning apparatus according to the fifth aspect of the invention, the contact pin is provided at a portion which penetrates the first elongated hole of the first guide member and the second elongated hole of the second guide member. Each has a bearing. Therefore, when the contact pin moves in contact with the outer peripheral end surface of the substrate, the contact pin can move while rolling along the outer peripheral end surface of the substrate. Therefore, it is possible to prevent the outer peripheral end surface of the substrate and the surfaces of the contact pins from being worn or damaged.

[0023]

1 is a plan view of a substrate alignment apparatus according to an embodiment of the present invention, and FIG.
It is the XX sectional view taken inside. The substrate alignment apparatus includes a first fixed guide 1, a second fixed guide 3 and a rotation guide 2.
And The first fixed guide and the second fixed guides 1 and 3 are formed in a disk shape, and the center thereof is the fixed shaft 4.
It is fixed to.

Further, the rotation guide 2 is the first fixed guide 1
And is inserted between the second fixed guides 3. The rotation guide 2 is rotatably attached to the fixed shaft 4 with a rotation bearing 5 interposed therebetween. Further, a bearing 6 is inserted between the lower surface of the first fixed guide 1 and the upper surface of the rotary guide 2,
A bearing 7 is inserted between the lower surface of the rotation guide 2 and the upper surface of the second fixed guide 3. The bearings 6 and 7 allow the rotation guide 2 to smoothly rotate with respect to the stationary first fixed guide 1 and second stationary guide 3.

A rotation guide drive unit 20 is attached to the outer peripheral end surface of the rotation guide 2. Rotation guide drive unit 20
Is a drive disc 21 that abuts against the peripheral edge surface of the rotation guide 2 to rotate the rotation guide 2, a drive motor 23 that applies a rotational force to the drive disc 21, and the drive motor 23 and the drive disc 2
1 is composed of a torque controller 22 interposed therebetween.

The torque controller 22 comprises a torque adjusting mechanism using a torsion bar and a coil spring, and a transmission. The torque controller 22 drives the drive motor 23 when the load applied to the drive disk 21 reaches a certain value.
To stop transmitting the rotation of the drive disk 21 to the drive disk 21. As a result, the drive disc 21 is controlled so that torque above a certain value is not transmitted to the rotation guide 2.

Further, the first fixed guide 1 and the second fixed guide 3 are formed with a plurality of first elongated holes 11 and 13 extending in the radial direction (six places in the illustrated example). Further, the rotation guide 2 is formed with a second elongated hole 12 extending in a direction inclined with respect to the radial direction. The second elongated hole 12 is arranged at a position overlapping the first elongated holes 11 and 13 formed in the first fixed guide 1 and the second fixed guide 3 when viewed from above. The second long hole 12 may be a long hole having a curvature as shown in the drawing, or may be a straight long hole.

The contact pin 8 is provided so as to pass through the first elongated holes 11 and 13 of the first fixed guide 1 and the second fixed guide 3 and the second elongated hole 12 of the rotation guide 2. . Resin washers 9 and 10 are attached to the abutment pin 8 as the first fixed guide 1,
It is attached so as to sandwich the second fixed guide 3 and the rotation guide 2. As a result, the posture of the contact pin 8 is held such that the longitudinal direction of the contact pin 8 is oriented in the vertical direction.

Further, the first fixed guide 1 and the rotation guide 2
The through hole 1 is provided in each of the second fixed guide 3 and
4a to 14c are formed. These through holes 14a
The support pins 16 move up and down through 14c, and the substrate 15 is moved up and down.

In the present embodiment, the first fixed guide 1 and the second fixed guide 3 constitute the first guide member,
The rotation guide 2 constitutes a second guide member, and the rotation guide drive section 20 constitutes a rotational force applying means and a regulating means.

Next, the substrate alignment operation in the substrate alignment apparatus having the above structure will be described. FIG. 3 is a plan view of a main part showing a moving state of the contact pin at the time of aligning the substrate, and FIG. 4 is a plan view showing a moving state of the substrate. In FIG. 4A, the central axis P of the substrate 15
Is held on the substrate holding plate 1 with a distance d from the normal reference axis Q.

From this state, the rotation guide drive unit 20 (see FIG.
The drive motor 23 (see (1)) is driven, and the alignment operation of the substrate 15 is started. The drive motor 23 is the drive disk 21.
The rotation guide 2 is rotated in a predetermined direction (counterclockwise in the case shown) through the.

In FIG. 3, when the rotation guide 2 is rotated, the contact pin 8 is pushed by the inner side surface 12a of the second elongated hole 12 and the inner side surface 11a of the first elongated hole 11 (13).
It is guided by (13a) and moves toward the reference axis Q.

Then, as shown in FIG. 4 (a), first, some abutment pins 8 abut the outer peripheral end face of the substrate 15 to move the substrate 15 while pushing it horizontally. As a result, the substrate 15 moves so that the central axis P of the substrate 15 gradually approaches the reference axis Q.

Then, as shown in FIG. 4B, the central axis P of the substrate 15 coincides with the reference axis Q when all the abutting pins 8 abut the outer peripheral end surface of the substrate 15. When the contact pin 8 can no longer move to the substrate 15 side, the torque controller 22 limits the amount of torque transmitted to the drive disk 21. Therefore, no further moving force is applied to the contact pin 8, and the substrate 15 is held in the aligned state.

For example, as shown in FIG. 1, first elongated holes 11.13 and second elongated holes 12 formed in the first fixed guide 1, the second fixed guide 3 and the rotary guide 2, respectively.
Are formed at positions symmetrical with respect to the reference axis Q. Therefore, the first elongated holes 11 and 13 and the second elongated hole 12
The plurality of contact pins 8 whose positions are defined by
Similarly, it is always held in a point-symmetrical position with respect to the reference axis Q. Therefore, as shown in FIG. 4A, all the contact pins 8 are located on the virtual circle 19 centered on the reference axis Q.
Then, when the rotation guide 2 rotates, a plurality of contact pins 8
Moves so as to reduce the diameter of this virtual circle 19. As a result, the center of the substrate 15 is moved to the center point of the virtual circle 19. Thereby, the central axis P of the substrate 15 coincides with the reference axis Q.

As described above, in the above-described embodiment, the substrate 15 can be aligned by completely abutting the abutting pin 8 even on the substrate 15 having a different diameter.

FIG. 5 is a sectional structural view of a substrate alignment apparatus according to a modification of the present invention. In this example, bearings 17 are provided at positions where the contact pins 8 pass through the first fixed guide 1, the rotation guide 2, and the second fixed guide 3, respectively. These bearings 17 allow the abutment pin 8 to rotate smoothly, avoid friction at the contact surface between the abutment pin 8 and the outer peripheral end face of the substrate 15, and prevent friction and damage to the outer peripheral end face of the substrate 15 and the abutment pin 8. Can be prevented.

In the above embodiment, the abutment pin 8 is configured to be held by the guides 1 to 3 by the resin washers 9 and 10, but the lower end of the abutment pin 8 is supported by other supports. It may be configured to be supported by a member.

Further, in the above embodiment, the first fixed guide 1 and the second fixed guide 3 having the same shape are arranged so that the contact pin 8 can be held vertically and horizontally moved. As long as the pin 8 can be moved in parallel while being held in the vertical direction, for example, one of the first fixed guide 1 and the second fixed guide 3 can be omitted.

[Brief description of the drawings]

FIG. 1 is a plan view of a substrate alignment apparatus according to an exemplary embodiment of the present invention.

2 is a cross-sectional structural view of the substrate alignment apparatus shown in FIG. 1 taken along line XX.

FIG. 3 is a main part plan view for explaining the operation of the substrate alignment apparatus.

FIG. 4 is a plan view showing a movement operation of the substrate in the substrate alignment apparatus.

FIG. 5 is a sectional structural view of a substrate alignment apparatus according to a modified example of the present invention.

FIG. 6 is a plan view and a side view of a conventional substrate alignment apparatus.

FIG. 7 is a diagram illustrating an operation of a conventional substrate alignment apparatus.

[Explanation of symbols]

 1 1st fixed guide 2 rotation guide 3 2nd fixed guide 4 fixed shaft 8 contact pin 11, 13 1st long hole 12 2nd long hole 15 board 16 support pin 20 rotation guide drive part 21 drive disk 22 torque Controller 23 Drive motor

Claims (5)

[Claims] 1. A substrate alignment apparatus for horizontally aligning the substrate by moving the substrate horizontally such that the central axis of the substrate supported horizontally coincides with a predetermined reference axis. At least 3 distributed and arranged on the circumference of a circle centered on the axis and movably guided in the radial direction of the circle.
A substrate alignment apparatus comprising: a single contact pin; and a contact pin drive means that moves the at least three contact pins toward the reference axis by equal distances to contact the outer peripheral end face of the substrate. 2. The abutment pin driving means includes a first guide member having at least three first elongated holes into which the at least three abutment pins are respectively inserted and extending in the radial direction, A second guide member having at least three second elongated holes into which at least three contact pins are inserted and extending in a direction inclined with respect to the radial direction of the circle; and the second guide member. The substrate alignment apparatus according to claim 1, further comprising: a rotating unit that rotates the first guide member about the reference axis. 3. The rotating means regulates the rotational force imparting means for imparting a rotational force to the second guide member and the rotational force imparted to the second guide member so as not to exceed a predetermined value. The substrate alignment apparatus according to claim 1 or 2, further comprising a regulation unit. 4. The second guide member is made of a disc-shaped member, and the first guide member is made of two plate-shaped members arranged above and below the disc-shaped member. Claim 1
4. The substrate alignment apparatus according to any one of 3 to 3. 5. The first portion on the outer peripheral surface of the contact pin.
5. The substrate alignment apparatus according to claim 2, wherein bearings are provided at positions penetrating the long hole and the second long hole, respectively.