JPH04293251A - Wafer positioning device - Google Patents

Abstract

PURPOSE:To enable the wafer delivery and the orientation flat alignment to be performed rapidly with high precision by a method wherein a wafer holding table and a holder are relatively turned so as to detect the wafer orientation flat by a detector provided on the holder. CONSTITUTION:A non contact sensor 17 as a detector mounted on the surface of a holder 37 in the peripheral part of a wafer holding table 26 is opposite to the peripheral part but in the non-opposite state to an orientation flat. Accordingly, the sensor 17 can detect the orientation flat of the wafer 1. On the other hand, a motor 55 is driven with one end of the holder 37 in the opposite state to a wafer carrier so that the holder 51a of an arm 51 may be aligned with the insertion position in the wafer carrier by driving the arm 51 in the wafer carrier direction. Next, the wafer carrier is lowered in specific dimension to deliver the wafer 1 to the holder 51a of the arm 51. Through these procedures, the wafer delivery and the orientation flat alignment can be performed rapidly with high precision.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer positioning apparatus for aligning a wafer with an orientation flat.

0002

2. Description of the Related Art For example, a semiconductor device manufacturing process includes a photolithography process. This photolithography process includes resist coating, exposure, and development steps. Generally, the above-mentioned resist coating process can be performed without regard to the crystal plane orientation of the wafer, but the exposure process must take the wafer plane orientation into consideration. That is, it is necessary to align the surface orientation of the wafer when transferring the wafer from the resist coating process to the exposure process.

[0003] The above-mentioned wafer is produced by slicing after providing an orientation flat (orientation flat) indicating a crystallographic reference direction within the wafer plane in the crystal orientation determined by X-ray orientation measurement on a bar-shaped silicon single crystal ingot. (the state shown in FIG. 6). Therefore, the positioning of the wafer 1 is performed by detecting the orientation flat 2.

A conventional wafer positioning device that positions the wafer 1 by detecting the orientation flat 2 is shown in FIG. In FIG. 7, 4 is a wafer transfer device of this positioning device, and 5 is an orientation flat aligning device.

[0005] The wafer transfer device 4 has a base 6 . A first mounting table 7 having a substantially flat upper surface is provided above the base 6. As shown in FIG. This first mounting table 7 is attached to the base 6 so as to be rotatable around a vertical axis, and is driven for positioning by a drive motor (not shown).

[0006] Further, a guide rail 8 is attached to one end of the first mounting table 7 in the width direction, and extends along the longitudinal direction of the first mounting table 7. A holding member 10 that holds an arm 9 for transferring the wafer 1 is slidably attached to the guide rail 8. The holding member 10 is positioned and driven by a driving means (not shown).

The arm 9 is held horizontally by the holder 10, and has one end extending toward one end of the first table 7 in the longitudinal direction. One end portion of the arm 9 is formed into a Y-shaped fork shape, and serves as a holding portion 9a for holding the wafer 1 on the upper surface.

[0008] The first mounting table 7 is disposed in a state where it is not rotationally driven so that one end surface in the longitudinal direction faces the wafer carrier 12 that holds the wafers 1 on which the resist coating process has been completed. That is, the first mounting table 7 can take out the wafer 1 from the wafer carrier 12 by driving the arm 9 in the direction of the wafer carrier 12.
An orientation flat alignment device 5 is arranged at a position 90 degrees out of phase with the wafer carrier 12.

The orientation flat alignment device 5 has a second mounting table 14. A wafer holding table 15 is attached to this second mounting table 14 . This wafer holding table 15 has an upper end as a suction part, and the suction part is provided so as to be able to protrude and retract from the upper surface of the second mounting table 14, and is rotated and positioned around a vertical axis by a driving means (not shown). It is designed to be driven.

A vacuum means (not shown) is provided inside the second mounting table 14 to generate a suction force on the suction portion of the wafer holding table 15. The wafer holding table 15 is capable of suctioning and holding the wafer 1 at its upper end.

On the upper surface of the second mounting table 14, a pair of positioning jigs 16, 16 each having one side formed in a shape along the outer peripheral surface of the wafer 1 are arranged with one side facing each other. It is located. This positioning jig 16,
16 are arranged line-symmetrically across the wafer holding table 15, and are driven in directions toward and away from each other by driving means (not shown).

That is, after placing the wafer 1 on the upper end of the wafer holding table 15, the pair of positioning jigs 16, 16 are driven in a direction toward each other, so that the jig 16 is placed on the outer periphery of the wafer 1. , 16 are engaged with each other, so that the center position of the wafer 1 can be aligned with the rotational axis of the wafer holding table 15.

A non-contact sensor 17 that can detect the position of the orientation flat 2 of the wafer 1 is fixed on the mounting surface 14a of the second mounting table 14. This non-contact sensor 17 is connected to the orientation flat 2 of the wafer 1.
is detected, and the rotation of the wafer holding table 15 is stopped at a predetermined position based on this detection signal.

Next, the operation of this device will be explained. The wafer 1 that has undergone the resist coating process is stored horizontally within the wafer carrier 12. The arm 9 is driven along the guide rail 8 in the direction of the wafer carrier 12 via the holding member 10 . The holding portion 9a of the arm 9 enters the fin tray 12 and is positioned so as to face below the wafer 1.

Once the holding portion 9a is positioned,
The holding portion 9a of the arm 9 holds the wafer 1 by driving the fin tray 12 downward by a small amount. The arm 9 is then driven in a direction away from the wafer carrier 12. In this way, the wafer 1 is taken out from the wafer carrier 12.

Next, the first mounting table 7 is rotated in the forward direction (direction indicated by arrow A) so that one end of the first mounting table 7 faces the orientation flat aligning device 5. Positioned.

When one end of the first mounting table 7 faces the orientation flat alignment device 5, the arm 9 is driven in the direction of the orientation flat alignment device 5. and,
The wafer 1 held in the holding part 9a is placed on the wafer holding table 1.
Position it above 5. In this state, the pair of positioning jigs 16, 16 are driven toward each other, and the center of the wafer 1 is aligned with the axis of rotation of the wafer holding table 15.

When the center of the wafer 1 coincides with the rotational axis of the wafer holding table 15, the wafer holding table 15 is driven upward while generating suction force, comes into contact with the lower surface of the wafer 1, and the wafer holding table 15 is moved upward while generating a suction force. 1 is separated upward from the holding portion 9a of the arm 9.

Next, the wafer holding table 15 is driven to rotate. The non-contact sensor 17 detects the position of the orientation flat 2 of the wafer 1, and sends this detection signal to a rotation driving means (not shown) between the non-contact sensor 17 and the wafer 1.
The rotation of the wafer holding table 15 is stopped so that the position of the wafer holding table 15 coincides with the position of the orientation flat 2. As a result, the wafer 1 is aligned (positioned) with its orientation flat.

Once the wafer 1 has been positioned, the wafer holding table 15 is driven downward. When the lower surface of the wafer 1 comes into contact with the upper surface of one end of the arm 9 again, the suction force of the wafer holding table 15 is released, and the wafer 1 is held by the holding portion 9a of the arm 9 again. Once the wafer 1 is held, the arm 9 is driven in a direction away from the orientation flat aligning device 5.

Next, the first mounting table 7 is driven to rotate in the opposite direction (the direction opposite to arrow A), and is positioned so that one end of the first mounting table 7 faces the wafer carrier 12. be done. The arm is then driven in the direction of the wafer carrier 12 to return the positioned wafer 1 to the wafer carrier 12. This completes the positioning of the wafer 1.

[0022]

By the way, in the above-described wafer positioning device, the orientation flat aligning device 5 and the wafer 1 are moved from the wafer carrier 12 to the orientation flat aligning device 5.
Two devices, a transfer device 4, are provided, and the wafer 1 must be transferred between these two devices 5 and 4. For this reason, the structure of the wafer positioning device described above becomes complicated, and the device as a whole may become larger. Further, since there are many steps for positioning, it may take time for positioning.

The object of the present invention is to perform the above-mentioned wafer transfer and orientation flat alignment in one device,
An object of the present invention is to provide a wafer positioning device that is compact and can be driven at high speed.

[0024]

[Means for Solving the Problems] The present invention includes a base, a holder provided on the base, a holding table provided on the upper surface of the holder, and the holder and the holding table. Vertical driving means for relatively vertical driving and rotational driving means for relatively rotational driving, and a positioning portion provided on the upper surface side peripheral portion of the holding table and formed coaxially with the axis of the relative rotation center of the holding table. a positioning jig having an arcuate surface, and a mounting portion formed at one end, the mounting portion being horizontally reciprocated in one direction passing through the axis of the arcuate surface at a predetermined distance from the upper surface of the holder. An arm provided at the periphery of the holding table is provided to raise the holding table relative to the holding body, and after transferring the wafer to the holding table, the holding table is moved relative to the holding table. and a detection means for detecting an orientation flat formed on the wafer by rotating the wafer.

[0025]

[Operation] According to such a configuration, the holding table holding the wafer and the holding body are relatively rotated, and the orientation flat of the wafer is detected by the detection means provided on the holding body, so that the wafer is positioning.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

Reference numeral 24 in FIG. 1 is a base of the wafer alignment apparatus of the present invention. A long rod 25 is erected approximately at the center of the upper surface of the base 24 with its axis perpendicular. The lower surface of a wafer holding table 26 (hereinafter abbreviated as "holding table"), which has an upper end surface as a mounting surface and has an outer diameter smaller than the outer diameter of the wafer 1, is fixed to the upper end of this rod 25.

Further, on the upper surface of the base 24, a short cylindrical holding member 27 having an inner diameter portion 27a larger than the outer diameter of the rod 25 is erected with its axis aligned with the axis of the rod 25. has been done.

One end of a motor bracket 28 is fixed to the upper end of the holding member 27. This motor bracket 28 is arranged approximately horizontally, and a first drive motor 29 with a vertical axis is attached to the lower surface of the other end with a drive shaft extending upward from the upper surface of the motor bracket 28. . A first drive pulley 30 is attached to the upper end of this drive shaft.

A cylindrical rotating body 31 having an outer diameter smaller than the inner diameter of the holding member 27 and an inner diameter slightly larger than the outer diameter of the rod 25 is attached to the inner diameter portion 27a of the holding member 27. 25, and is rotatably attached to the inner peripheral surface of the inner diameter portion 27a via a pair of bearings 33, 33.

The upper end of the rotating body 31 is connected to the holding member 2.
A flange portion 31a is formed at the upper end of the flange portion 31a, which protrudes radially outward. Further, a first driven pulley 34 is attached to the outer peripheral surface of the rotating body 31 at approximately the same height as the first driving pulley 30.

A drive belt 35 is stretched between the first drive pulley 30 and the first driven pulley 34, and the rotating body 31 can be rotationally driven by operating the first drive motor 29. ing. The first drive motor 29, the first drive pulley 30, the first driven pulley 34, and the first drive belt 35 constitute a rotary drive means of the present invention.

On the upper surface of the flange portion 31a formed at the upper end of the rotating body 31, a pair of guides 36, 36 are vertically provided in parallel and spaced apart. This guide 36, 36
A holding body 37 is slidably provided. This holding body 37 is formed into a rectangular box shape with an open bottom surface, and a partition plate 37a is provided vertically. This partition plate 37a
A slider 38 that slidably engages with the guide 36 is provided on one side of the guide 36 . Therefore, the holding body 37 is slidable in the vertical direction along the guide 36. The upper end of the rod 25 and the holding table 26 protrude upward from the upper surface of the holding body 37. Furthermore, a U-shaped first support member 41 is attached to the upper surface of the flange portion 31a of the rotating body 31.

A screw shaft of a ball screw mechanism 39 serving as a vertical drive means is rotatably attached to the first support member 41 with its axis perpendicular. A second driven pulley 40 is attached to the lower end of this screw shaft. On the other hand, a nut 39a constituting the ball screw mechanism 39 is fixed to one side surface of the partition plate 37a.

Furthermore, as shown in FIG. 4, the rotating body 31
A U-shaped second support member 42 is attached to the other side of the partition plate 37a of the flange portion 31a. A second drive motor 4 is mounted on the upper wall of the second support member 42.
3 is provided with its axis perpendicular and its drive shaft extending between the upper and lower walls. A second drive pulley 44 is attached to the drive shaft of the second drive motor 43 at approximately the same height as the second driven pulley 40 . A second drive belt 45 is stretched between the second drive pulley 44 and the second driven pulley 40.

Therefore, when the second drive motor 43 is operated, the screw shaft of the ball screw mechanism 39 is rotationally driven via the second driven pulley 44, and the nut 39 is rotated.
a can be driven upwards along the screw axis. This allows the holding body 37 to be driven in the vertical direction.

As shown in FIG. 4, a channel-shaped positioning jig holding member 47 that opens upward is attached to one end in the longitudinal direction of the upper surface of the holding body 37. As shown in FIG. A pair of positioning jigs 48, 48 (hereinafter abbreviated as "jigs") are held on both end surfaces of the positioning jig holding member 47. As shown in FIG. 3, the pair of jigs 48, 48 are block-shaped members arranged in parallel at a certain distance in the width direction of the holder 37.

The corner portions of the pair of jigs 48, 48, which are formed by one end surface in the longitudinal direction and an opposing surface, are formed into curved surfaces 48a, 48a along the outer peripheral surface of the wafer 1. Moreover, these pair of jigs 48, 48 are connected to the curved surfaces 48a, 4.
When the outer peripheral edge of the wafer 1 is brought into contact with the rod 25 (holding table 26), the center of the wafer 1 is brought into contact with the rod 25 (holding table 26).
It is arranged so that it coincides with the central axis of.

The partition plate 37a on the upper part of the holder 37
As shown in FIG. 2, a guide rail 49 is attached to the other side of the holder 37 along the longitudinal direction of the holder 37. A slider 50 is slidably attached to the guide rail 49.

This slider 50 has an arm 51 which will be described later.
One lower end 52a of an arm holding member 52 having a substantially U-shape that holds the is fixed. Further, a connecting member 53 is attached to one lower end portion 52a of this arm holding member 52 with its axis being vertical.

Further, as shown in FIG. 4, the other lower end portion 52b of the arm holding member 52 is disposed astride one of the jigs 48 and between the opposing surfaces of the pair of jigs 48, 48. The other lower end 52b of the arm holding member 52 includes
As shown in FIG. 3, a holding section 5 holds the wafer 1 at one end.
An arm 51 having a diameter 1a formed thereon is mounted horizontally. The holding portion 51a is formed into a substantially Y-shaped fork shape so that the holding table 26 can be accommodated therein.

Furthermore, as shown in FIG. 2, the partition plate 37
Driving means 54 for driving the arm holding member 52 along the guide rail 49 is provided on the other side of a. This driving means 54 includes a third driving motor 55 which is provided with its axis perpendicular to a portion of the partition plate 37a corresponding to one end of the guide and whose driving shaft extends upward; A third drive pulley 56 is attached to the drive shaft of the motor 55, and a third drive pulley 56 is rotatably held at a portion corresponding to the other end of the guide rail 49 at approximately the same height as the third drive pulley 56. 3 driven pulley 57,
The third driving pulley 56 and the third driven pulley 57
and a third drive belt 58 stretched between. The connecting member 53 is connected to this drive belt 58.

Therefore, by operating the third drive motor 55, the arm holding member 52 and the arm 51 can be driven along the guide rail 49 via the connecting member 53.

Furthermore, a non-contact sensor 17 as a detection means is attached to the upper surface of the holding body 37 in the peripheral area of the holding table 26 with its imaging surface facing upward. This non-contact sensor 17 faces the periphery of the wafer 1 held on the table 26 and does not face the orientation flat 2. Therefore, the non-contact sensor 17 can detect the orientation flat 2 of the wafer 1. Next, Figure 5
The operation of positioning the wafer 1 by this wafer positioning device will be described with reference to A(a) to (e) and FIGS. 5B(a) to (e).

As shown in FIGS. 5A(a) and 5B(a), this wafer positioning device is operated in the third position shown in FIG.
The drive motor 55 is activated to drive the arm 51 in the direction of the wafer carrier 12 (the state shown in FIG. 1). As a result, the holding portion 51a of the arm 51 is inserted and positioned within the wafer carrier 12. Next, the wafer carrier 12 is driven in a downward direction by a predetermined distance as in the conventional example, and the wafer 1 is attached to the holding portion 51a of the arm 51.
is passed on.

Once the wafer 1 is held by the holding portion 51a of the arm 51, the arm 51 is driven in a direction away from the wafer carrier 12. As a result, as shown in FIGS. 5A(b) and 5B(b), the arm 51
The outer peripheral surface of the wafer 1 is brought into contact with the curved surfaces 48a, 48a of the pair of jigs 48, 48, and the center of the wafer 1 is aligned with the central axis of the rod 25 (holding table 26), that is, the rotation center of the holder 37. (state shown in Figure 3)
. When the center of the wafer 1 coincides with the central axis of the rod 25, the arm 51 stops at that position while holding the wafer 1 in the holding portion 51a.

Next, the second drive motor 43 (shown in FIG. 4) is activated to operate the ball screw mechanism 39 and drive the holder 37 downward. As a result, the arm 51 is lowered relative to the holding table 26 provided at the upper end of the rod 25 as shown in FIG. passed on.

Next, as shown in FIGS. 5A(c) and 5B(c), the first drive motor 29 is operated to rotate the holding body 37 together with the rotating body 31. At this time, the holding table 26 attached to the upper end of the rod 25
The wafer 1 placed on the upper surface of this holding table 26 does not rotate.

By rotationally driving the holder 37, the non-contact sensor 17 scans the periphery of the wafer 1, so that the orientation flat 2 formed on the wafer 1 can be detected. When the non-contact sensor 17 detects the orientation flat 2, the rotation of the holder 37 is stopped at that position.

Next, the second drive motor 43 is activated to drive the holder 37 upward. As a result, the wafer 1 held on the holding table 26 is transferred to the arm 51 again.
is delivered to the holding section 51a. That is, the wafer 1 is delivered to the holding portion 51a of the arm 51 with the orientation flat 2 positioned at a predetermined position (aligned with the orientation flat).

Once the wafer 1 is held by the arm 51, the first drive motor 29 is activated, and as shown in FIGS.
As shown in FIG. 5A(d) and FIG. 5B(d), the holder 37 and the arm 51 are rotated and positioned so that one end of the holder 37 faces the wafer carrier 12 again.

Next, as shown in FIGS. 5A(e) and 5B(e), the third drive motor 55 is operated to position and insert one end portion 51a of the arm 51 into the wafer carrier 12, The wafer 1 is returned to its original position on the wafer carrier 12. Due to these things,
The positioning of the wafer 1 is completed.

According to this configuration, the wafer 1 can be taken out from the wafer carrier 12 using one device, the orientation flat 2 detected, the wafer 1 positioned based on the orientation flat 2, and then returned to the wafer carrier 12. Can be done. Moreover, since the arm 51 only needs to be reciprocated once along the longitudinal direction of the holder 51a, the operation of the apparatus is simplified and the wafer 1 can be positioned at high speed and with high precision.

Furthermore, as shown in FIG. 7, the conventional example is provided with two devices, a transfer device 4 and an orientation flat aligning device 5, but in the present invention, one device is used to perform continuous operations. Therefore, a compact wafer positioning device with a simplified configuration can be obtained. Note that this invention is not limited to the above-mentioned embodiment, and can be modified in various ways without changing the gist of the invention.

For example, in the above embodiment, the holding table 26 (rod 25) is fixed and the holding body 37 is made rotatable and movable in the vertical direction, but in another embodiment, the holding body 37 is fixed. The holding table 26 (rod 25) may be rotatably driven and movable in the vertical direction.

According to such a configuration, the holding table 2
After detecting the orientation flat 2 by rotating the
), the operation leading to FIG. 5B(d), that is, the operation of making one end of the holder 37 face the wafer carrier 12, is unnecessary, so the positioning operation is simplified and the wafer 1 can be positioned faster. It is possible to do so. Furthermore, one of the holding table 26 and the holding body 37 may be provided to be freely rotatable, and the other may be provided to be freely movable up and down.

[0057]

As described above, the wafer positioning device of the present invention includes a base, a holder provided on the base, a holding table provided on the upper surface side of the holder, and a wafer positioning device according to the present invention. a vertical drive means for relatively driving the body and the holding table up and down; and a rotation drive means for relatively rotating the body and the holding table;
a positioning jig having an arcuate surface serving as a positioning part provided on the upper surface side peripheral part of the holding table and formed coaxially with the axis of the relative rotation center of the holding table, and a mounting part formed at one end; an arm provided on the upper surface of the holder at a predetermined distance so that the mounting portion horizontally reciprocates in one direction passing through the axis of the arcuate surface; and an arm provided on the periphery of the holding table; and a detection means for detecting an orientation flat formed on the wafer by relatively rotating the holding table after transferring the wafer to the holding table by raising the holding table relatively to the holding body. do.

[0058] According to this configuration, the wafer transfer by the arm and the alignment of the orientation flat by the non-contact sensor can be performed continuously in one device, and a compact wafer positioning device can be obtained. be.

[Brief explanation of drawings]

FIG. 1 is a partially sectional side view showing a wafer positioning device of the present invention.

FIG. 2 is a side view showing FIG. 1 from the opposite side.

FIG. 3 is a plan view as well.

FIG. 4 is a front view as well.

FIG. 5 is a process diagram showing a wafer positioning process.

FIG. 6 is a plan view showing a wafer.

FIG. 7 is a plan view showing a conventional wafer positioning device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Wafer, 2... Orientation flat, 17... Non-contact sensor (detection means), 24... Base, 26... Wafer holding table (holding table), 29... First drive motor (rotation drive means)
, 37... Holder, 39... Ball screw mechanism (vertical drive means), 48... Positioning jig, 51... Wafer holding arm (arm).

Claims (1)

[Claims] [Claim 1] A base, a holder provided on the base, and a holding table provided on the upper surface side of the holder,
A vertical driving means for relatively driving the holding body and the holding table vertically and a rotational driving means for relatively rotating the holding body and the holding table; A positioning jig has an arcuate surface that is formed coaxially with the axis and serves as a positioning portion, and a placement portion is formed at one end. A wafer is delivered to the holding table by an arm provided to horizontally reciprocate in one direction, and an arm provided at the periphery of the holding table to raise the holding table relative to the holding body. A wafer positioning apparatus comprising: a detection means for detecting an orientation flat formed on the wafer by relatively rotating the holding table after the wafer is aligned.