JPH01184844A - Prealignment device for wafer - Google Patents

Abstract

PURPOSE:To reduce remarkably the number of components constituting an apparatus, by using one detecting element to detect a wafer, and transferring a wafer in one direction on a horizontal plane. CONSTITUTION:A moving stand 3 is transferred at a position where a one- dimensional sensor 6 is engaged with the outer peripheral part of a wafer 1. A wafer rotating table 4 is turned once by the action of a driving motor 42. When the rotating table 4 rotates, an output waveform as shown by figure is obtained as an output of the one-dimensional sensor 5. By processing this data with a calculating circuit, the maximum displacement and angle of center position of the wafer 1, and the rotation position of an orientation flat 1a can be obtained. Based on the result, the center positioning of the wafer 1 is performed by transferring the moving stand 3 and the rotating table 4.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to a) wafer pre-alignment apparatus, particularly for wafer pre-alignment of equipment that requires positioning and processing of wafers in semiconductor manufacturing processes. 1 ton of equipment
Regarding 1/ζ.

[Conventional technology]

As a conventional technique, for example, there is a wafer pre-alignment apparatus described in Japanese Patent Publication No. 59-46029.

A conventional wafer pre-alignment device includes a positioning bin for roughly positioning a wafer to be transferred.

a wafer moving table that detachably holds the wafer on a horizontal surface and is movable in the horizontal direction, and a first detection element that engages with the outer periphery of the wafer and detects the position of the outer periphery in the horizontal direction; A wafer rotating table rotatably supports the wafer, which is no longer held by the wafer moving table, on a horizontal surface, and the wafer is engaged with an orientation flat formed on the outer periphery of the wafer to detect the position of the orientation flat. Control means for moving and positioning the wafer moving table and the wafer rotating table in the horizontal plane direction and rotational direction based on the difference between the detected value and the tolerance range of the second detecting element and the thirteenth second detecting element. It consists of:

Next, a conventional wafer pre-alignment apparatus will be described in detail with reference to the drawings.

FIG. 6 is a top view showing an example of a conventional wafer pre-alignment apparatus, and FIG. 7 is a sectional view of the conventional apparatus shown in FIG.

The wafer glia alignment apparatus shown in FIG.

A positioning bin 11 for roughly positioning the wafer 1 to be transferred, and a wafer moving table 1 for detachably holding the wafer 1 on a horizontal surface and making it movable in the horizontal direction.
2, a first detection element 141 that engages with the outer periphery of the weno 1 and detects the position of the outer periphery in the horizontal plane, and rotates the weno 1 released from the holding by the low evaporation moving table 12 onto the horizontal plane. A wafer (rotary table 13) and second detection elements 151, 152° that engage the orientation flat 1a formed on the outer periphery of the wafer 1 and detect the position of the orientation flat 1a. 15
3, and the first and second extraction elements 141, 151°15
2, due to the difference between the detected value of 153 and the allowable range.

Wafer moving table 12 and wafer rotating table 13
control means for moving and positioning in the horizontal plane direction and rotational direction.

Next, the configuration of the conventional device described above will be explained in more detail.

The wafer pre-alignment apparatus is shown in FIG.

Positioning bins 111, 112, and 113 are provided as shown by arrow B to roughly position the wafer 1 being transferred.

A wafer moving table 12 that removably holds the wafer 1 on a horizontal surface is provided on the underside of the wafer 1 roughly positioned by the positioning bins 111, 112, and 113. This wafer moving cheagle 12ri, a guide 121 that guides the wafer moving table 12 in the X direction and the Y direction, an X direction moving motor 122 and a Y direction moving motor 12 that move the wafer moving table 12 in the X direction and the Y direction.
3 and.

The wafer moving table 12 includes a vacuum passage 124 that applies a vacuum to the upper surface of the wafer moving table 12.

A first detection element consisting of a plurality of photoelectric elements 141, 142, 143 and 144 for detecting the position of the outer periphery in the X direction and the Y direction is placed on the outer periphery of the approximately positioned sea urchin/S'l. It is provided on a circumference that is approximately the same as the outer circumference of 1.

Further, a wafer moving table 12 is provided on the lower surface side of the wafer 1.
A wafer rotating table 13 surrounding the wafer is provided.

Now turn table 13 to sea urchin.

Rotation motor 1 that rotates wafer rotation wheel 2
31, and a guide 132 for vertically guiding the wafer rotating tool 7' and for rotating the tool 13.

The wafer rotary table 13 is configured by a rotary table up/down cylinder 133 that moves the wafer rotary table 13 in the vertical direction.

Further, the orientation infrastructure 1aK on the outer periphery of the wafer 1 is positioned at a position where a second detection element consisting of a plurality of optical ridge elements 151, 152 and 153 arranged in the direction of transport of the wafer 1 engages. It is provided.

Further, the first and second detection elements are connected to a control means, and detected values in the X direction, Y direction, and rotational direction of the wafer 1 are manually inputted. Here, this control means includes an X-direction movement motor 122 and a Y-direction movement motor 123 that move the wafer movement table 12t in the X and Y directions, and a rotation motor 13 that rotates the wafer (2) rotation table 13.
1 and are connected to each other.

Next, the operation of the above-mentioned conventional device will be explained in detail.

The transferred wafers 1 are placed in bins 111 and 112°11.
3 and is approximately positioned. Wafer moving table 1
2d, it is positioned in advance by sliding to the right and engages downwardly with the weno 1 which is in the above-mentioned approximate position.

I support this. At the same time, a vacuum is sent to the upper surface of the wafer moving table 12 from the true passageway 124.

The wafer 1 is attracted to the wafer moving chiffle 12.

Next, the wafer moving table 12 moves to the left while adsorbing the wafer 1, and returns to the center position, that is, the center position of the hole in the support table. Here, the wafer moving table 12 removes the suction of the wafer 1 .

At the same time, the wafer rotary table 13 is raised by the action of the rotary table 7° up/down cylinder 133, and the wafer 1 is lengthened.

Next, the wafer rotation table 13 is rotated by the action of the rotation motor 131. The wafer rotary table 13 rotates, the original section resistors 151, 152 and 153 engage with the outer periphery of the wafer 1, and the rotational position of the orientation quadruple flat 1a is detected. At this position, wafer rotary table 1
30 rotations are stopped, the wafer rotation table 13 is lowered, and the rotational positioning of the wafer 1 is completed.

Next, a vacuum is applied again to the upper surface of the wafer moving table 12 of the wafer 1, and the wafer 1 is vacuum-adsorbed. In this state, the optical/soldering elements 141 and 142 engaged with the outer periphery of the wafer 1
, 143 and 144 are determined. This detected value is taken into the control section, and the X-direction movement motor 122 and the Y-direction movement motor 123 are operated to determine the center position of the phenol 1 and complete the pre-alignment of the phenol.

[Problem that the invention seeks to solve]

The conventional wafer pre-alignment device described above has a large number of detection elements for detecting the wafer, and also uses means for moving the wafer in two directions to move the wafer back and forth horizontally, so the structure is complicated and the device is difficult to use. There was a drawback that it became an island price. Another disadvantage is that there are many input/output objects to the control section, making the control circuit complex.

The conventional wafer pre-alignment apparatus described above has the disadvantage that it is not easy to change to a corresponding wafer because the detection element that determines the wafer position is uniquely fixed to the corresponding wafer. there were.

[Failure to solve the problem]

The wafer pre-alignment apparatus of the present invention includes: a wafer transfer table that supports a wafer on a horizontal surface and moves in a vertical direction; and a movable table on which the wafer transfer table is mounted and moves in a uniaxial direction within the horizontal plane.

a wafer rotation table that is provided to protrude from an elongated hole provided in the center of the moving table and rotatably supports the wafer on a horizontal surface in a detachable manner; A one-dimensional seven-sensor is provided on the top of the wafer to detect the horizontal position m of the outer surface of the wafer, and the amount of wafer slippage in the horizontal direction and rotational direction is calculated from the detected value of one rotation of the -dimensional sensor. The device includes a calculation circuit, and a control path (b) for receiving signals from the calculation circuit and moving and positioning the moving table and the wafer rotation table in a horizontal plane direction and in a rotational direction.

〔Example〕

Next, an embodiment of the present invention will be described in detail with reference to one drawing.

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a top view of the embodiment shown in FIG. 1, and FIG. 3(a).

(bl is a sectional view of this embodiment shown in Fig. 2, Fig. 4(a)
.

fbl is an output waveform diagram of the one-dimensional seven-turbine when the wafer is rotated, and FIGS. 5 tal to tel are explanatory diagrams illustrating the operation of the embodiment shown in FIG. 1.

The glial alignment device for sea urchins is shown in Figure 1.

A wafer transfer table 2 that supports the wafer 1 on a horizontal plane and moves vertically, a moving table 3 that carries the wafer transfer table 2 and moves horizontally, and a slotted hole provided in the center of the moving table 3. A wafer rotary table 4 is provided to protrude and rotatably support the wafer 1 horizontally and detachably; and an outer wall of the wafer 1 is provided on the upper part of the movable table 3 in the same direction as the moving direction of the movable table 3. a one-dimensional sensor 5 that detects the horizontal position of the wafer 1, a calculation circuit that calculates the horizontal and rotational deviation amount of the wafer 1 from the detected value of one rotation of the -dimensional sensor 5, and a calculation rotation (not shown). The control circuit includes a control circuit (not shown) that receives signals and moves and positions the moving table 3 and the wafer rotation table 4 in the horizontal plane direction and in the direction of rotational force.

Next, the configuration of the present invention will be explained in more detail.

The wafer pre-alignment apparatus of the present invention is provided with a wafer transfer table 2 that supports transferred wafers 1 on a horizontal surface and can move them vertically. The wafer transfer table 2 includes a guide 21 that guides the wafer transfer table 2 in the vertical direction.

The wafer transfer table 2 includes a cylinder 22 for moving the wafer transfer table 2 up and down.

The wafer transfer table 2 is provided on a movable table 3 that is movable in a uniaxial direction in a horizontal plane.

Here, the moving table 3 includes a moving plate 31 mounted on the upper part of the wafer transfer table 2t, a guide 32 that guides the moving plate 31 in a horizontal direction with respect to the base 10, and a ball nut 33 provided on the moving plate 31. , a ball screw 34 for driving and moving the ball screw 33, and a moving motor 35 for driving the ball screw 34.

At the center of the movable stage 3, a wafer rotation table 4 that rotatably supports the wafer 1 on a horizontal plane is fixed to a base 10. At this point ζ, the wafer rotation table 4 has a base lO
It is composed of a rotation motor 41 that rotates the wafer rotation table 4 and a vacuum passage 42 that acts on the upper surface of the wafer rotation table 4, and protrudes from a long hole 36 provided in the movable plate 31. It is provided.

Further, a one-dimensional sensor 75 is provided on the upper part of the moving table 3 and used in conjunction with the moving direction of the moving table 3.

The position of the outer part of the wafer l in the horizontal concave direction is detected by this -dimensional sensor v5.

The one-dimensional sender 5 is connected to a four-output circuit (not shown),
The detected value at the outer periphery of the wafer when the wafer 1 is rotated once is calculated manually. This calculation circuit is connected to a control circuit. Furthermore, the VC control circuit is connected to a moving motor 3 that drives the moving table 3.
5 and four rotation motors for rotating four wafer rotation tables.

Next, the operation of this embodiment will be explained in detail.

As shown in Fig. 2, the wafer 1 has been transferred.
d. The transfer is stopped based on the rear ratio value of the first sensor 5, which is a detection element provided on the moving table 3. That is, the wafer transport by the wafer transport stage 1, for example, the belt transporter or the robot arm is stopped.

At this time, as shown in FIG. 5 (ta+), a wafer transfer table 2 is positioned on the lower surface side of the wafer 1 and is raised to support the wafer 1.

Next, as shown in FIG. 5(b), the wafer transfer table 2 is moved according to the size of the wafer 1, that is, according to the outer diameter of the wafer l obtained in advance, and the wafer is rotated to the approximate center of the wafer 1. Align the center of table 4. Here, the wafer transfer table 2 is lowered by the action of the wafer transfer table up/down cylinder 220, and the wafer 1 is placed on the wafer rotation table 4. At the same time, a vacuum is applied to the upper surface of the wafer rotation table 4.

Zero-order one-dimensional sensor that vacuum-chucks wafer 1? The moving table 2 is moved to a position where the wafer 5 engages the outer peripheral portion of the wafer 1. Next, the wafer rotation table 4 is rotated by the action of the rotation motor 42. When the phenol rotary table 4 rotates, an output waveform as shown in FIG. 4 is obtained as the output of the one-dimensional center t5. By processing this data in a calculation circuit, the maximum deviation and angle of the center position of υ wafer 1,
Also, the rotation position of the orientation infrastructure, t-
You can ask for it. That is, if the center of Pheno Sl and the center of the wafer rotation table 4 coincide.

As shown in FIG. 4, the output of the one-dimensional sensor 5 indicates only the rotational position of the oriental eye flat 1a. Furthermore, if the center of the wafer 1 and the center of the wafer rotation table 4 are slightly deviated, the one-dimensional seven-sensor 5 as shown in FIG.
The output is a combination of fluctuations due to the amount of deviation and fluctuations indicating the rotational position of the orientation infrastructure 1a. By separating these data using the &41 section, the maximum deviation amount and angle of the center position of the wafer 1, and the rotational position 1at' of the orientation flat 1a can be determined.

Here, based on the maximum vibration and angle of the center position of the wafer 1, the movable table 3 and the Kueno 1 rotary table 4 are moved to determine the center position *f: position of the wafer 1.

As shown in FIG. 5 (cl), the wafer rotating table 4 is moved so that the direction α of the maximum deviation of the phenol 1 coincides with the movement direction β of the moving table 3. Here.

The wafer rotating table 4 releases the adsorption of the wafer 1 and rotates the wafer 1.
Next, by the action of the cylinder 220 for raising and lowering the wafer transfer table,
The wafer transfer table 2 rises and supports the wafer 1. Next, the wafer 1 is moved by 1/2 of the amount of deviation of the wafer 1 on the moving stage 3, and the center of the rotary table 4 is aligned with the center of the wafer 1. Here, the wafer transfer table 2 is lowered by the action of the cylinder 220 for raising and lowering the wafer transfer table, and the wafer 1
Place it on the rotating table 4. At the same time, a real g! The wafer 1 is vacuum-adsorbed. Furthermore, the orientation infrastructure for wafer 1,
The wafer rotation table 4 is moved based on the rotational position of the wafer and the wafer is orientated.

) Position the rotational position of 1a. With the above steps, the pre-alignment of the wafer I is completed.

〔Effect of the invention〕

The wafer pre-alignment apparatus of the present invention uses one detection element to detect the wafer, and instead of using a large number of detection elements to detect the wafer and moving the wafer in two directions in the horizontal plane, By making the internal movement only in one direction, the number of parts that make up the rice stack can be significantly reduced, resulting in an inexpensive device. Similarly, since the number of constituent parts is greatly reduced, there are fewer input/output targets for the control section, and the control circuit becomes simpler.

Furthermore, in the wafer pre-alignment apparatus of the present invention, instead of the detection element that detects the position It to the sea urchin being uniquely set to 1 for the corresponding query, the detection element that detects the position to the sea urchin is moved to S. By mounting the sensor on a stand), the detection position relative to the wafer can be changed, and the corresponding wafer can be easily changed.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a top view of the embodiment shown in FIG. 1, and FIG. 3(a). lb) is a sectional view of this embodiment shown in Fig. 2, Fig. 4(a)
. (bl is a one-dimensional output waveform diagram of C/l when rotating the 9eva, FIGS. 5(a) to (C) are explanatory diagrams explaining the operation of the embodiment shown in FIG. 1, The factor is a top view showing a conventional example, and FIG. 7 is a cross-sectional view of the conventional apparatus shown in the sixth factor. , 2...Wafer delivery table, 21
...Guide, 22...Cylinder for wafer transfer table up and down, 3...Moving table, 31...
...Movement plate, 32...Guide. 33...Ballner, ), 34...Ball screw, 35...Moving unit, 4...
・Unino rotating table. 41...Rotation motor, 42...Vacuum passage, 5...-dimensional sensor, 10...
Base, 111,112゜113...Bin, 1
2...Feno 1 moving table, 121...
... Kite, 122 ... Motor for moving in the X direction,
123... Motor for moving in the Y direction, 124...
...Vacuum passage, 13...pheno 5IIl! 1
Rotation table, 131...Rotation motor, 132
...Guide, 133... Cylinder for rotating table up and down, 141,142゜143.144...
・Light area control element, 151, 152° 153... Light/electronic element. Agent Patent Attorney Oto Uchihara Figure 4 (Shinken 5th figure)

Claims (1)

[Claims] a wafer transfer table that supports the wafer horizontally and moves vertically; a moving table on which the wafer transfer table is mounted and moves in a uniaxial direction in a horizontal plane; a wafer rotating table which is provided to rotate and detachably support the wafer on a horizontal surface, and a wafer rotating table which is provided on the upper part of the moving table so that the moving direction of the moving table is the same as the moving direction of the moving table and which supports the wafer in the horizontal plane on the outer periphery of the wafer. a one-dimensional sensor that detects the position; a calculation circuit that calculates the amount of deviation of the wafer in the horizontal direction and rotational direction from the detection value of one rotation of the one-dimensional sensor; A wafer pre-alignment apparatus comprising: a control circuit for moving and positioning a rotary table in a horizontal direction and in a rotational direction.