JPH10135301A - Wafer processing equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To transport a wafer whose weight has increased due to an increase in size, the transport apparatus itself has also increased in size, and it takes longer to transport the wafer than in the past in order to prevent displacement and damage during transport, and wafer processing is performed. It is difficult to shorten the transport time in the process preparation process in the apparatus. A cassette mounting part for mounting a cassette containing wafers therein and an atmospheric robot for loading and unloading wafers.
6, a load lock chamber 6 having vacuum exhaust means capable of switching between atmospheric pressure release and vacuum sealing, and a wafer 2 in a chamber 19 for processing the wafer 2 in a vacuum atmosphere. And a vacuum sealing section having a vacuum robot 17 for carrying in / out the wafer 2, and the wafer 2 transferred by the atmospheric robot 16 from the cassette mounting chamber 4 into the load lock chamber 6.
The alignment unit 21 for recognizing the center position of the wafer 2 and correcting the position of the wafer 2 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a wafer processing apparatus in a semiconductor manufacturing facility, and more particularly to a wafer processing apparatus particularly suitable for reducing a processing time in a semiconductor manufacturing facility.

[0002]

2. Description of the Related Art As one of processing apparatuses in a semiconductor manufacturing facility, there is a wafer processing apparatus for performing processing such as plasma etching on a wafer. FIG. 5 shows a schematic layout diagram of a conventional wafer processing apparatus.

As shown in FIG. 5, a wafer processing apparatus 1 includes a cassette mounting chamber 4 having a cassette mounting section 3 for mounting a cassette (not shown) for storing and transporting wafers 2 and a vacuum pump (not shown). Transfer chamber 5 for transferring the wafer 2 in a vacuum atmosphere, the cassette mounting chamber 4 and the transfer chamber 5
Between the load lock chamber 6 and the unload lock chamber 7. The load lock chamber 6 is provided with gates 8 and 10, and the unload lock chamber 7 is provided with gates 9 and 11. The gates 8 and 9 are located at the boundary with the cassette mounting chamber 4. The gate 11 is located at the boundary with the transfer chamber 5. The load lock chamber 6 and the unload lock chamber 7 are provided with a vacuum pump (not shown) and a vacuum sensor (not shown) via a valve (not shown), and are provided by a control device (not shown). Switching between vacuum atmosphere and open to atmosphere is possible.

[0004] Load lock chamber 6, unload lock chamber 7
The wafer loading table 1 which can be moved up and down
3 and 14 are provided, and a wafer transfer device 16 and a wafer transfer device 17 are provided inside the cassette mounting chamber 4 and the transfer chamber 5. Hereinafter, for convenience of explanation, the cassette mounting chamber 4
Is referred to as an atmospheric robot 16 and the wafer transfer device 17 in the transfer chamber 5 is referred to as a vacuum robot 17.

Atmospheric robot 1 provided in cassette mounting chamber 4
6 is a wafer 2 stored in a cassette (not shown).
Are placed one by one on the wafer alignment unit 12, an orientation flat (hereinafter, abbreviated as an orientation flat) and a V notch are detected, aligned, and then transferred again into the load lock chamber 6 by the atmospheric robot 16. It is placed on the placing table 13. When the wafer 2 is mounted on the wafer mounting table 13 and the atmospheric robot 16 exits the load lock chamber 6, the gate 8 is closed and the control device (not shown) operates the vacuum pump (not shown) to operate the load lock chamber. The inside of the chamber 6 is evacuated to the same degree of vacuum as the inside of the transfer chamber 5.
Thereafter, the gate 10 is opened, and the vacuum robot 17 takes out the wafer 2 from the wafer mounting table 13 and mounts the wafer 2 via the gate 18 on the wafer mounting table 20 provided in each chamber 19 evacuated according to the processing step. Place.

When the processing of the wafer 2 is completed, the vacuum robot 17 places the processed wafer 2 on the wafer mounting table 14 in the unload lock chamber 7 via the gate 11. At this time, the inside of the unload lock chamber 7 is kept in a vacuum atmosphere. When the vacuum robot 17 exits from the gate 11 and the gate 11 is closed, the control device (not shown) releases the vacuum state, makes the unload lock chamber 7 in the same state as the atmosphere, and opens the gate 9. The atmospheric robot 16 moves the wafer mounting table 14 in the unload lock chamber 7 through the gate 9.
The wafer 2 is taken out of the cassette 2 and stored in a cassette provided in the cassette mounting section 3.

If all the wafers 2 housed in the cassette have been processed in the wafer processing apparatus 1, a transfer means or an operator (not shown) transfers the cassette to a subsequent process.

[0008]

In recent years, wafers have been increased in size in order to increase the production of semiconductors.
As the weight of the wafer increases, the size of the transfer device itself also increases. However, in order to convey the increased weight and to prevent displacement or breakage during the conveyance, as a result, the conveyance takes longer than before. There is a demand for an improvement in the processing capability of the entire semiconductor manufacturing apparatus by reducing the processing time in the entire wafer processing process.

The time required for processing a wafer in the wafer processing apparatus 1 includes, in addition to the processing time in each chamber 19 and the transfer time between the chambers 19 by the vacuum robot 17,
It includes the transfer time of the wafer 2 by the atmospheric robot 16, the alignment time in the wafer alignment unit 12, the opening / closing operation of each gate in the load lock chamber 6 and the unload lock chamber 7, and the evacuation time or open time to atmosphere. The processing time for the wafer itself depends on the required processing steps and cannot be reduced.

An object of the present invention is to solve the above problems and to provide a wafer processing apparatus capable of shortening the time in a processing preparation step in the wafer processing apparatus.

[0011]

SUMMARY OF THE INVENTION A wafer processing apparatus according to the present invention has an atmospheric pressure comprising a cassette mounting portion for mounting a cassette containing wafers and an atmospheric transfer device for loading and unloading wafers from the cassette in the cassette mounting portion. An open part, a relay part which is in contact with the atmospheric pressure open part and has a vacuum exhaust means capable of switching between atmospheric pressure release and vacuum sealing, and a relay part interrupts the atmospheric pressure open part, so that in a vacuum atmosphere And a vacuum sealing unit having a vacuum transfer unit for loading and unloading the wafer into and out of the processing chamber for processing the wafer, wherein a center position of the wafer transferred by the atmospheric transfer unit from the atmospheric pressure release unit into the relay unit is provided in the relay unit. And a position correcting means for correcting the position of the wafer.

[0012]

1 to 4 show a wafer processing apparatus according to an embodiment of the present invention. The same parts as those in FIG. 5 are denoted by the same reference numerals, and description thereof will be omitted.

The embodiment shown in FIG. 1 has a positioning unit provided in the load lock chamber. FIG. 2 is an enlarged view of a cross section taken along line AA in FIG.

As shown in FIG. 1, when the atmospheric robot 16 takes out the wafer 2 stored in a cassette (not shown) provided in the cassette mounting section 3 in the cassette mounting chamber (atmospheric pressure release section) 4a. The gate 8 of the load lock chamber (relay section) 6 opens. The wafer 2 is placed on the positioning unit 21 provided in the load lock chamber 6. Atmospheric robot (atmospheric transport device)
When the 16 exits from the load lock chamber 6, the gate 8 closes and the position adjusting unit (position correcting means) while the inside of the load lock chamber 6 is kept in a vacuum atmosphere by a command from the control device 50.
21 detects the orientation flat and the V notch of the wafer 2 and performs the alignment. The control device 50 also performs other controls of the wafer processing device.

FIG. 2 is an enlarged view of an AA cross section of FIG.
An example of the position correcting means will be described. FIG. 2 shows a state in which the wafer 2 is placed in the load lock chamber 6 and the alignment is performed during evacuation.

The positioning unit 21 comprises a rotating mechanism for rotating the wafer mounting table 15, a wafer position detecting mechanism, and a wafer position adjusting mechanism.

The rotation mechanism for rotating the wafer mounting table 15 has a function of rotating the wafer mounting table 15 on which the wafer 2 is mounted in a horizontal plane and a function of moving the wafer mounting table 15 in the vertical direction. Provided wafer mounting table 1
5, the upper end of the rotating vertical shaft 22 is fixed. The O-ring 23 provided at the bottom of the load lock chamber 6 allows the load lock chamber 6 to rotate vertically with respect to the rotating vertical shaft 22.
The inside is kept airtight. In addition, a guide 24 provided on the outer periphery of the rotating vertical shaft 22 holds the rotating vertical shaft 22 so as to be rotatable up and down. The rotating vertical shaft 22 includes an O-ring 23 and a guide 24.
And communicates with the outside of the load lock chamber 6. The lower end of the rotary vertical shaft 22 located outside the load lock chamber 6 communicates with a bearing 25 and is connected to the upper end of the rotary shaft of a motor 27 by a coupling 26.
7, the rotation vertical shaft 22 is rotated, and the wafer mounting table 15 is rotated in a horizontal plane. In addition, for example, an air cylinder 28 is fixedly provided on a guide 29 below the motor 27, and in FIG.
Shows a state in which is pushed up. In this state, the wafer 2 is mounted on the wafer mounting table 15, but when the air cylinder 28 releases the push-up of the motor 27, the rotating vertical shaft 22 is lowered and the wafer mounting table 15 is lowered.

The wafer position detecting mechanism has a function of detecting the position of the wafer 2 placed on the wafer placing table 15, and the viewing window 30 is placed on the upper wall of the load lock chamber 6.
An O-ring 3 is provided on the lower wall located immediately below the viewing window 30 by providing a vacuum seal with the ring 31.
A vacuum sensor 3 is provided, and displacement sensors 34 and 35 such as a laser type line sensor are provided outside the load lock chamber 6 of the viewing windows 30 and 32, respectively. When the wafer 2 is rotated by the rotation mechanism described above, the displacement sensors 34 and 35 continuously detect the displacement of the edge portion of the wafer 2 and the orientation flat and the V-notch position through the viewing windows 30 and 32 in accordance with the rotation position.

A specific detection method will be described later with reference to FIGS. Next, a wafer position adjusting mechanism for adjusting the position of the wafer based on the eccentricity of the wafer detected by a detection method described later will be described with reference to FIG.

Guide 3 provided at the bottom of load lock chamber 6
6, a position correction table 37 is provided so as to be movable,
A screw 38 communicates with the inside. One end of the screw 38 is rotatably held by a bearing 39, and a gear 40 is connected to the other end. A gear 41 is engaged with the gear 40, and a rotation shaft 42 of the gear 41 communicates with the outside while keeping the load lock chamber 6 airtight by an O-ring 43.

The lower end of the rotary shaft 42 located outside the load lock chamber 6 communicates with a bearing 44 and is connected to the upper end of a rotary shaft of a motor 46 by a coupling 45. Rotate around.

When the motor 46 rotates the rotating shaft 42, the gear 41 located in the load lock chamber 6 rotates and rotates the gear 40 together. As the gear 41 rotates, the screw 38 rotates. Screw 38 is the position correction table 37
The position correction table 37 slides on the guide 36 and moves in the horizontal direction by the rotation of the screw 38.

The wafer mounting surface of the position correction table 37 has a shape having a space on the inside where the wafer mounting table 15 can be moved up and down.

The detection of the center shift amount of the wafer 2 and the orientation flat and the V notch by the above-described wafer position detection mechanism will be briefly described with reference to FIGS.

FIG. 3 shows the wafer mounting table 15 shown in FIG.
FIG. 4 is a view schematically showing a positional relationship between a wafer mounted on the upper part and a displacement sensor 34 provided in the load lock chamber 6, and FIG. 4 shows a state when the wafer mounting table 15 on which the wafer is mounted makes one rotation. 6 is a graph showing a change in a light blocking amount detected by displacement sensors 34 and 35. For convenience of explanation, a wafer having a V notch was used instead of the orientation flat.

The center of the wafer mounting table 15 is defined as a point Oa, and the center of the wafer is defined as a point Ob. When the wafer is mounted on the wafer mounting table 15 without the center position shifting, the two coincide. The wafer actually mounted on the wafer mounting table 15 is indicated by a solid line as a circle 2a, and the wafer mounted without any displacement (when the points Oa and Ob match) is indicated by a two-dot chain line as a circle 2b. Indicated by In addition, circle 2
It can be said that a is eccentric with respect to the circle 2b. A simulated disk having a radius from the point Oa, which is the center of the wafer mounting table 15, to the end of the displacement sensor 34 on the side of the point Oa from the point Oa is indicated by a dashed line as a circle 2c. The center of this simulated disk is point Oa, and the displacement sensor 3
Do not block 4,35 light.

On the other hand, the diameter of the wafer 2 to be processed is known in advance, and the wafer 2 is placed on the wafer mounting table 15.
When the sensor is placed in an ideal state with no center displacement, the light shielding amount (width of the light shielding area) of the displacement sensors 34 and 35 is determined by the distance L.
Set to 0. Also, the closest point between the circle 2c and the circle 2a is indicated by the circle 2
Assuming that point B is on point a, the maximum separation point is the intersection of the line connecting point B and point Ob with circle 2a, and is point C on circle 2a.

The wafer mounting table 15 is rotated in the direction of the arrow by 360 ° with the measurement start positions of the displacement sensors 34 and 35 as reference points. When the center position of the wafer mounted on the wafer mounting table 15 coincides with the point Oa which is the center of the wafer mounting table 15, that is, in the case of the circle 2b shown in FIG. 3, the curve 2b in FIG. As shown in FIG.
Only at the time point (notch location), and becomes constant at other angles. Therefore, it can be seen that the V notch exists at the portion of the angle Θ1.

On the other hand, in the case of the circle 2a whose center position is shifted, when the wafer mounting table 15 is rotated once, the curve 2 in FIG.
As shown in a, the light shielding amount is changed from the angle 0 at the start of rotation to the angle Θ.
The angle gradually decreases up to 2 and the angle Θ2 to the angle Θ2 + 180
° gradually increases. Note that, at the time of the angle Θ3, the light shielding area is sharply changed.

Here, the minimum light shielding amount by the circle 2a is determined by the distance L
In addition to calculating as 1, the angle corresponding to the minimum light shielding amount is obtained as an angle Θ2. Note that the maximum amount of light shielding is determined by the distance
Then, the angle corresponding to the maximum light shielding amount is the angle Θ2 + 180
°.

As described above, the displacement sensors 34, 35
Is calculated as the distance L1 and the corresponding angle Θ2 is calculated as the eccentricity of the wafer 2, and the center shift amount and the center shift direction of the wafer 2 (hereinafter referred to as the eccentric direction).

The maximum light shielding amount calculated as the distance L2 may be calculated as the eccentric amount of the wafer 2.

Next, referring again to FIG.
Will be described. First, the wafer mounting table 1
5 is rotated by the above-described rotary up-down mechanism, and the direction of eccentricity of the wafer 2 and the direction in which the displacement sensors 34 and 35 of the load lock chamber 6 are provided coincide. Here, the wafer mounting table 15 is lowered after rotating by an angle Θ2, and the wafer 2 is mounted on the position correction table 37. At this time, the moving distance of the position correction table 14 on which the wafer 2 is placed can be obtained by the following equation.

That is, moving distance = | L0-L1 | (absolute value of value obtained by subtracting distance L1 from distance L0) or |
(L2-L1) / 2 | (the absolute value of 1/2 of the value obtained by subtracting the distance L1 from the distance L2).

That is, the wafer 2 moves leftward in FIG. 2 by the moving distance obtained by the above equation, and the center of the wafer 2 coincides with the rotation center of the wafer mounting table 15. In addition, the rotation distance of the position correction table 14 on which the wafer 2 is mounted is rotated by an angle Θ2 + 180 °, and | L0−L2 |
The wafer 2 may move to the right in FIG. 2 as (the absolute value of the value obtained by subtracting the distance L2 from the distance L0).
In addition, it is rotated by an angle を 2, and the moving distance is | L0−L2 |
The wafer 2 may move to the left in FIG. 2 as (the absolute value of the value obtained by subtracting the distance L2 from the distance L0).

When the operation by the position correction table 37 is completed, the wafer mounting table 15 is raised by the rotary up-down mechanism without rotating to the initial height. When the wafer mounting table 15 starts to rise, a controller (not shown) controls the inside of the load lock chamber 6 and the transfer chamber 5 based on the output from a vacuum sensor (not shown) for detecting the pressure in the load lock chamber 6. Then, after confirming that the inside of the chamber 19 has the same degree of vacuum, the gate 10 is opened.

The vacuum transfer robot (vacuum transfer device) 17 in the transfer chamber 5 transfers the wafer 2 whose center position has been corrected. In addition, while opening the gate 10 in a vacuum atmosphere state,
The wafer mounting table 15 may be rotated again to align the orientation flat or the V notch of the wafer 2 in a desired direction.

Incidentally, if necessary, the unload lock chamber 7
A similar positioning unit may be provided in the inside. In this case, alignment can be performed when the air is released to the atmosphere.

As described above, since the center position deviation of the wafer is detected and corrected while performing vacuum production in the load lock chamber 6, the time in the processing preparation process in the wafer processing apparatus can be reduced.

[0040]

According to the present invention, the position correcting means provided in the relay unit recognizes the center position of the wafer and corrects the position of the wafer during the vacuum sealing by the vacuum exhaust means provided in the relay unit. The time in the process preparation process in the wafer processing apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a layout of a wafer processing apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a cross section taken along line AA of FIG.

FIG. 3 shows displacement sensors 34, 3 provided in a wafer and a load lock chamber of the wafer processing apparatus according to the embodiment shown in FIG.
FIG. 6 is a diagram showing a positional relationship with the fifth embodiment.

4 shows a displacement sensor 3 when the wafer mounting table of the wafer processing apparatus in one embodiment shown in FIG.
FIG. 4 is a diagram illustrating a change in a light blocking amount detected by the light-receiving elements 4 and 35.

FIG. 5 is a diagram showing a layout of a conventional wafer processing apparatus.

[Explanation of symbols]

1: Wafer processing device 2: Wafer 3:
Cassette loading section 4, 4a: Cassette loading chamber 5: Transfer chamber 6:
Load lock chamber 7: Unload lock chamber 8, 9, 10, 11: Gate 12: Wafer alignment unit 13, 14, 15: Wafer mounting table 16: Wafer transfer device (atmospheric robot) 17: Wafer transfer device (vacuum robot) ) 18: Gate 19: Chamber 20: Wafer mounting table 21: Positioning unit 22: Rotating vertical axis 23: O-ring 24: Guide 25: Bearing 26: Coupling 27: Motor 28: Air cylinder 29: Guide 30, 32 : Viewing window 31, 33: O-ring 34, 35: Displacement sensor 36: Guide 37: Position correction table 38: Screw 39: Bearing 40, 41: Gear 4
2: Rotating shaft 43: O-ring 44: Bearing 45: Coupling 46: Motor

Claims (2)

[Claims] An atmospheric pressure release section comprising a cassette mounting section for mounting a cassette containing wafers therein and an atmospheric transfer device for carrying wafers in and out of the cassette in the cassette mounting section; and an atmospheric pressure release section. A relay unit that has vacuum exhaust means that can switch between atmospheric pressure release and vacuum sealing, and the relay unit blocks the atmospheric pressure release unit, and carries wafers in and out of the processing chamber that processes wafers in a vacuum atmosphere. Position correcting means for recognizing a center position of a wafer transferred by an atmospheric transfer device from an atmospheric pressure release unit in the relay unit and correcting the position of the wafer. A wafer processing apparatus comprising: 2. The wafer processing apparatus according to claim 1, further comprising a control device for operating the position correcting means during the operation of the evacuation means provided in the relay section.