JPH07263518A - Method and apparatus for transferring semiconductor wafer, and wafer treatment method - Google Patents

Abstract

PURPOSE:To correct central dislocation and rotational dislocation in a contactless manner relative to the mounting position of a carrying apparatus. CONSTITUTION:A stage 11 capable of rising and falling and rotatable relative to the main body 9 of a robot is mounted on the main body 9 of robot. An arm supporting body 17 equipped with an arm 16 is arranged on a rail 15 in such a manner that said supporting body 17 can travel along a rail 15 on the stage 11. A pair of distance sensors 20 and 21 arranged at both the sides of the stage 11 in width direction are placed on the arm 16 and detect the periphery of a wafer W passing between the distance sensors 20 and 21. A microcomputer MC built in a controller C calculates the central dislocation and rotating dislocation of the wafer W relative to the arm 16 based on detection signals from the distance sensors 20 and 21. The arm 16 temporarily puts the wafer W on a table 19, corrects its attitude angle and then mounts the wafer W again. In addition, the arm corrects the attitude angle so as to permit the mounting of the wafer W to the target position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention picks up semiconductor wafers one by one from a carrier (cassette) and transfers the wafers to, for example, a processing tray or the like which is set in advance at a predetermined position to transfer the semiconductor wafers without displacement. The present invention relates to an apparatus, a transportation method, and a semiconductor wafer processing apparatus.

In the wafer processing process, wafers are usually stored in a carrier in lot units. For example, when performing a predetermined process on a wafer by a wafer processing apparatus such as a sputter processing apparatus, the wafers are taken out one by one from a carrier, transferred to a processing tray provided at a predetermined position in the wafer processing apparatus, and placed. There is a need to. Usually, a transfer robot that automatically transfers a wafer is provided in the wafer processing apparatus.

In the wafer processing step, in order to process the wafer under more stable conditions, it is necessary to place the wafer on the processing tray accurately without misalignment. Therefore, how to place the wafer transferred by the transfer robot on the processing tray without misalignment is important for stable processing of the wafer.

[0004]

2. Description of the Related Art Conventionally, there is a wafer processing apparatus having a transfer robot of this type, for example, as shown in FIG. As shown in FIG. 11, the wafer processing apparatus 41 includes a processing chamber 42, a vacuum transfer chamber 43, and two load lock chambers 44.
The chambers 42 to 44 are partitioned from each other by shutters (not shown) that can be opened and closed. The load lock chamber 44 is provided with a carry-in entrance for carrying in the wafer W, and a shutter 44a is provided at the carry-in entrance so as to be openable and closable. The carrier 45 is placed in the wafer processing apparatus 41 at a predetermined position corresponding to the loading port of each load lock chamber 44. An alignment unit 46 is arranged in the wafer processing apparatus 41 at a position corresponding to each carrier 45. The transfer robot 47 is arranged between the carrier 45 in the wafer processing apparatus 41 and the load lock chamber 44. The transfer robot 47 moves along the rail 48 as shown in FIG.
Moving body 49 traveling in the left-right direction, a stage 49a rotatably provided on the moving body 49, and a stage 49a.
And an arm 50 that runs along a rail (not shown). The arm 50 is rotated by the rotation of the stage 49a.
The posture angle of can be changed.

The transfer robot 47 places the wafers W stored in the carrier 45 on the arm 50 one by one,
First, it is conveyed to the alignment unit 46. Then, after the position is corrected by the alignment unit 46, it is conveyed to the load lock chamber 44 and placed on the processing tray 51 in the load lock chamber 44. The processing tray 51 is transferred from the load lock chamber 44 through the vacuum transfer chamber 43 to the processing chamber 42 by a predetermined path.
A predetermined process such as spattering is performed in the chamber 2.

As shown in FIG. 12, the alignment unit 46 is provided with a turntable 52 at the center, and a pair of fixed guides 53 and movable guides 54 are provided on both sides of the turntable 52. Also, turntable 5
The reflection type sensor 55 is arranged at a position corresponding to the outer circumference of the wafer W shown in FIG.
5, the orientation flat f formed on the edge of the wafer W can be detected.

The wafer W is placed on the turntable 52, the movable guide 54 is operated, and the wafer W is pressed against the contact surface 53a of the fixed guide 53, so that the center point of the wafer W is first turned. The position is corrected so as to coincide with the rotation center of. Then turntable 52
Is rotationally driven at a predetermined speed, and at the same time, the position of the orientation flat f of the wafer W is detected by the sensor 55 operated. That is, the detection signal from the sensor 55 is turned off at a position corresponding to the orientation flat f of the wafer W, and the position of the orientation flat f is calculated from the rotation angle of the turntable 52 which is turned off. Then, when the center point of the orientation flat f is located on the axis of the arm 50 that faces the turntable 52 and stands by, the rotation of the turntable 52 is stopped. Then, the arm 50 is advanced in the axial direction to place the wafer W on the turntable 52. As a result, the wafer W is placed on the arm 50 in a state where the center deviation and the rotation deviation are corrected. The wafer W thus transferred to the load lock chamber 44 is placed on the processing tray 51 with high positional accuracy.

[0008]

However, the alignment unit 46 is arranged at a different place on the transfer path connecting the carrier 45 and the load lock chamber 44 due to the space. Therefore, there is a problem that the transfer robot 47 has to be moved to the alignment unit 46 arranged outside the transfer path, and it takes an extra time for transfer.

The alignment unit 46 shown in FIG.
According to the above, the wafer W is guided by the outer peripheral surface of the guides
4, the guides 53 and 54 are contaminated by contaminants such as resist applied to the wafer surface,
There is a concern that the contaminants may be attached to other wafers W to contaminate the wafers W in a chain.

For example, Japanese Patent Laid-Open No. 9634/1988 discloses that
An alignment apparatus is disclosed which corrects the position of the wafer W on the transfer path of the wafer W in a non-contact manner. However, although this alignment apparatus can correct the rotational deviation of the wafer W, it cannot correct the central deviation of the wafer W. As a result, the wafer W is eccentric to the processing tray.
Is placed, and there is a problem that the processing cannot be performed stably due to the eccentricity.

According to the transfer robot disclosed in JP-A-1-108740, the center deviation of the wafer W with respect to the arm is corrected, but the rotation deviation of the wafer W is not corrected and the transfer robot is arranged outside the transfer path. Had to go through the alignment unit. As a result, it becomes a problem that the stable processing cannot be performed due to the rotation deviation of the wafer W with respect to the processing tray, and the time for carrying the wafer W is long.

The present invention has been made in view of the above problems, and an object thereof is to correct a center deviation and a rotation deviation of a wafer with respect to a mounting portion of a transfer means without contact and on a transfer path. It is an object of the present invention to provide a semiconductor wafer transfer apparatus, a transfer method, and a semiconductor wafer processing apparatus capable of performing the above.

[0013]

In order to solve the above-mentioned problems, in the present invention, the transfer means is provided with a mounting portion on which the semiconductor wafer is mounted, and the semiconductor wafer is moved from a predetermined position by moving along a predetermined transfer path. Transport to position. The deviation amount detecting means makes the deviation amount between the virtual center set on the mounting portion and the center point of the semiconductor wafer mounted on the mounting portion non-contact with the semiconductor wafer on the transfer path. To detect. The deviation angle detecting means determines the deviation angle between the reference line set on the mounting portion and the reference line set on the semiconductor wafer mounted on the mounting portion with respect to the semiconductor wafer on the transfer path. Detect by contact. The position correction means is capable of mounting the semiconductor wafer on the target position based on the deviation amount and the deviation angle detected by the deviation amount detecting means and the deviation angle detecting means without a center deviation and a rotation deviation. Correct the placement position of.

[0014]

Therefore, the semiconductor wafer arranged at the initial position is mounted on the mounting portion and moved on the predetermined transfer path by the transfer means. During the transportation, the displacement amount detecting means detects the displacement amount between the virtual center of the mounting portion and the center point of the semiconductor wafer mounted on the mounting portion. In addition, the deviation angle between the reference line of the mounting portion and the reference line of the semiconductor wafer mounted on the mounting portion is detected by the deviation angle detecting means during the transportation. The position of the semiconductor wafer is corrected by the position correcting means on the basis of the detected deviation amount and deviation angle so that the semiconductor wafer can be placed on the target position without center deviation and rotation deviation. Then, the semiconductor wafer is transferred to the target position by the transfer means and placed on the target position with high positional accuracy without center deviation and rotation deviation.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment embodying the present invention will now be described with reference to FIGS.
This will be described with reference to FIG. As shown in FIG. 3, the wafer processing apparatus 1 includes a processing chamber 2, a vacuum transfer chamber 3 and two load lock chambers 4, and a shutter (not shown) that can be opened and closed between these chambers 2 to 4. Are divided. A load port for the wafer W is provided in the load lock chamber 4, and the load port can be opened and closed by a shutter 4a. The carrier 5 is mounted on a carrier mounting portion 5a provided at a position corresponding to the carry-in port of each load lock chamber 4 in the wafer processing apparatus 1, and the wafer W is placed on the carrier 5 in lot units. It is housed in. A transfer robot 6 is provided between each carrier 5 placed in the wafer processing apparatus 1 and each load lock chamber 4 so as to be able to travel in the left-right direction in FIG. The transfer robot 6 takes out the wafers W one by one from the carrier 5, transfers the taken-out wafers W to the load lock chamber 4, and places them on the processing tray 8. The processing tray 8 is transferred to the processing chamber 2 along the broken line arrow in FIG. 3 while maintaining its posture.

Each chamber 2-4 is connected to a vacuum pump (not shown), and the inside of each chamber 2-4 is depressurized by driving the vacuum pump. In the state where the shutter 4a is opened and the load lock chamber 4 is exposed to the atmospheric pressure, the load lock chamber 4 and the vacuum transfer chamber 3 are shut off, and the load lock chamber 4 and the vacuum transfer chamber 3 are opened, The vacuum transfer chamber 3 and the processing chamber 2 are set so as to be shut off from each other, and the inside of the processing chamber 2 is always kept at a high vacuum.

As shown in FIGS. 1 and 2, the robot main body 9 constituting the transfer robot 6 is provided with a plurality of rollers 10 which are in contact with the rails 7 on a base 9a formed below the robot main body 9.
The roller 10 is driven to rotate by a motor (not shown) so that it can move along the rail 7. On the upper part of the robot body 9, a stage 11 can be lifted and lowered via a support shaft 12 and rotatably supported with respect to the support shaft 12. That is, the support shaft 12 is arranged slidably with respect to the robot body 9 in the axial direction (vertical direction).
A stage 11 is rotatably arranged on the upper part of the. The stage 11 is driven up and down via a support shaft 12 that is slid via a belt transmission mechanism (not shown) by driving a motor 13 housed in the robot body 9,
Driven by a motor 14 housed in, the rotary shaft 12 is driven to rotate.

As shown in FIG. 1, one rail 15 extending in the longitudinal direction is arranged on the upper surface of the stage 11.
An arm support 17 that supports the arm 16 in a horizontal state is provided so as to be able to travel on the rail 15 by driving a motor 18. The arm 16 has a two-pronged portion on which the wafer W is placed. Further, the stage 11 has an insertion hole 11a formed at a position corresponding to the support shaft 12 and communicating with the inside of the support shaft 12 formed in a pipe shape. A table 19 supported by a support shaft 19a inserted through the insertion hole 11a and the support shaft 12 is installed in the center of the stage 11 while being fixed integrally with the robot body 9.
That is, the stage 11 includes the robot body 9 and the table 19
With respect to the center of the table 19 as the center of rotation.

As shown in FIG. 3, the stage 11 is in its original position when the arm 16 faces the carrier 5. Moreover, the state shown in FIG.
7 is the original position, and in this original position, the center point of the table 19 and the virtual center O set as the setting center of the wafer W placed on the arm 16 coincide with each other. When the stage 11 is in the original position, the arm support 17 moves from the original position to a position where the arm 16 corresponds to the wafer W in the carrier 5, and the stage 11 is rotated approximately 180 ° from the original position (FIG. 10). State), the arm 16 can be moved from its original position to a position where the arm 16 corresponds to the processing tray 8 of the load lock chamber 4. The traveling speed of the arm support 17 is set to a constant speed V.

As shown in FIGS. 1 and 2, the stage 11
A pair of distance sensors 20 and 21 are arranged on both sides in the width direction of the arm support 17 that travels to return to the original position from the carrier 5 side while the stage 11 is arranged at the original position. The outer peripheral surface of the wafer W placed on the arm 16 is set to be detectable. The distance sensors 20 and 21 are set so as to be activated at the same time when the arm support 17 for mounting the wafer W on the arm 16 starts the return travel from the carrier 5 side to the original position. The distance sensors 20 and 21 are arranged so as to be displaced from each other in the longitudinal direction of the stage 11 so as not to detect detection light (or detection wave) on the other side.

As shown in FIGS. 1 and 2, the robot body 9 is connected to the control device C through a flexible wiring 22, and the motors 13, 14, 18 and the distance sensors 20, 21 are connected.
The control unit C controls the driving of the above components. The control device C has a built-in microcomputer MC,
The transfer robot 6 performs a position correcting operation and a transfer operation of the wafer W by the microcomputer MC executing a control program stored in advance.

The microcomputer MC receives the detection signals from the distance sensors 20 and 21 for a predetermined time t (se).
c.) The movement direction of the wafer W is calculated on the X axis, and the distance from the distance sensors 20 and 21 to the outer peripheral surface of the wafer W is calculated based on the detection signal input on the XY axis plane set on the Y axis. The point coordinates are plotted sequentially. Then, the microcomputer MC creates the graph data shown in FIG. 5 in which only the left half of the outer circumference of the wafer W of FIG. 4 is plotted based on the detection signal from the distance sensor 20, and based on the detection signal from the distance sensor 21, FIG. The graph data shown in FIG. 6 in which only the right half of the outer circumference of the wafer W is plotted is created. The microcomputer MC approximates each graph data of FIGS. 5 and 6 by the least square method, and calculates an approximate expression of a circle representing the outer circumference of the wafer W. Then, the center coordinates (Xa, Ya) of the circle determined from the calculated approximate expression of the circle are used as the coordinates of the center P of the wafer W placed on the arm 16. Then, the microcomputer MC calculates the center shift of the center P of the wafer W with respect to the virtual center O of the arm 16.

Further, the microcomputer MC has an area in which plot data is arranged on a straight line in each graph data,
That is, a straight line area having a constant inclination is obtained, the inclination in the linear area is obtained by the least square method, and the position of the orientation flat f is recognized from the inclination. The data in this straight line region is not used as data for obtaining an approximate expression of a circle representing the outer circumference of the wafer W. still,
The arm 16 is located above the table 19 at the original position of the stage 11, and the arm 16 does not engage with the table 19 when the arm support 17 moves. Further, the carrier 5 is mounted on the carrier mounting portion 5a which can be lifted and lowered in the wafer processing apparatus 1, and the stage 11 in which the wafer W to be processed next in the carrier 5 is at the original position height.
A control device (not shown) controls the elevation so that the height of the arm 16 is set to correspond to that of the upper arm 16.

Next, the operation of the transfer robot 6 configured as described above will be described. The vacuum pump is pre-driven,
The processing chamber 2, the vacuum transfer chamber 3 and the load lock chamber 4 which compose the wafer processing apparatus 1 shown in are set to a predetermined vacuum state in advance. In the wafer processing apparatus 1, two carriers 5 each containing the unprocessed wafer W in lot units are placed at predetermined positions. Further, the transfer robot 6 stands by on the rail 7 in a position corresponding to the carrier 5 on the left side of FIG.

When a work start command signal is input to the microcomputer MC, the controller C drives the motor 18 so that the arm support 17 travels from the original position along the rail 15 toward the carrier 5 and the arm 16. Are inserted in the carrier 5 below the one wafer W to be transported. Next, the motor 13 is driven to raise the stage 11 by a predetermined amount, and the wafer W is placed on the arm 16.
After that, the motor 18 is driven in the reverse direction, and the arm support 17 which mounts the wafer W on the arm 16 starts the return traveling toward the original position at a constant speed V. Simultaneously with the start of the return travel of the arm support 17, the distance sensors 20, 2
1 is activated.

As shown in FIG. 7A, the wafer W placed on the arm 16 passes between the distance sensors 20 and 21 while being transferred from the carrier 5 to the original position. The distance sensors 20 and 21 detect the reflected light (or the reflected wave) reflected on the outer peripheral surface of the wafer W and output a detection signal according to the distance to the outer peripheral surface of the wafer W. The microcomputer MC inputs the detection signals from the distance sensors 20 and 21 every predetermined time t (sec.), And calculates the distance from the distance sensors 20 and 21 to the outer peripheral surface of the wafer W based on the detection signal.

Here, as shown in FIG. 4, the wafer W is eccentric with respect to the virtual center O of the arm 16 and the orientation flat f with respect to the axial center line B of the arm 16 is the base of the arm 16. It is assumed that the arm 16 is placed on the arm 16 in a state of being rotationally displaced so as not to be orthogonal at the end side. In this case, the microcomputer MC sequentially points on the XY-axis coordinates on the outer periphery of the left half of the wafer W in FIG. 4 based on the detection signal from the distance sensor 20 at predetermined intervals (= Vt) with respect to the X-axis. Plot to create graph data as shown in FIG. In addition, based on the detection signal from the distance sensor 21, points on the outer periphery of the right half of the wafer W in FIG. 4 are sequentially plotted on the XY-axis coordinates at predetermined intervals (= Vt) with respect to the X-axis, and FIG. Create graph data as shown in.

The microcomputer MC is shown in FIGS.
An approximate expression of a circle representing the outer circumference of the wafer W is calculated by the least square method based on each graph data plotted in a semicircle shape as shown in FIG. As a result, approximate equations of circles represented by the following equations (1) and (2) are obtained from the respective graph data of FIGS. 5 and 6.

(X-Xa) ² + (Y-Ya) ² = R ² (1) (X-Xb) ² + (Y-Yb) ² = R ² (2) (1), (2) The radius R of the wafer W is calculated from the equation.
The coordinates of the center P of the wafer W are calculated as (Xa, Ya) and (Xb, Yb) from the equations (1) and (2), respectively. Here, both Xa and Xb are position coordinates of the center P on the X axis, and usually have substantially the same value. Further, regarding the positional deviation of the center P of the wafer W with respect to the virtual center O of the arm 16, when the coordinates of the virtual center O are (Xo, Yo), the X-direction component of the positional deviation is (Xa + Xb) / 2−Xo, Y. The direction component is expressed as (Yb-Ya) / 2. Note that FIG. 5 and FIG.
The broken line in the middle is the outer peripheral line of the wafer W when the virtual center O and the center P coincide with each other.

Further, a straight line region having a constant slope is obtained from the plots in the respective graph data of FIGS. 5 and 6, and in this case, OE ≦ X ≦ OS of FIG. 6 is obtained as the straight line region. The microcomputer MC has OE ≦ X ≦ in FIG.
Orientation flat f from inclination in OS
The tilt in the XY axis coordinates is calculated. Then, the rotation deviation angle α ° of the wafer W is calculated based on the inclination.

As shown in FIG. 7B, the arm support 1
When 7 reaches the original position, the stage 11 is lowered and the wafer W on the arm 16 is placed on the table 19.
As shown in FIG. 9, the microcomputer MC draws a perpendicular line from the center of the table 19 (which coincides with the virtual center O of the arm 16 in this original position) to the orientation flat f of the wafer W placed on the table 19. , An intersection S of an extension of the perpendicular line on the virtual center O side and an arc passing through the center point Q of the processing tray 8 and centered on the virtual center O is calculated. The microcomputer MC has the arm 1
Orientation flat f is arranged on the base end side of 6,
The rotation amount β of the stage 11 that makes the axis B of the arm 16 parallel to the line segment PS is calculated. That is, ∠OSP
= Θ °, and the rotation amount β is calculated as (α + θ) °.

Then, as shown in FIGS. 7C and 9, the microcomputer MC calculates the rotation amount β (=
Based on (α + θ) °, the motor 14 is driven to rotate the stage 11 counterclockwise in the figure by (α + θ) °. As a result, the axis line B of the arm 16 becomes parallel to the line segment PS, and the axis line B is inclined by (90−θ) ° with respect to the orientation flat f.

As shown in FIG. 8A, the stage 11 is lifted from this state, and the wafer W is placed on the arm 16. Then, the stage 11 is further rotated counterclockwise from the state shown in FIG. 9 until the virtual point S coincides with the center Q of the processing tray 8. As a result, the stage 11 rotates θ ° counterclockwise in FIG. 9 with respect to the line segment OQ.
The state shown in FIG. At this time, the axis B of the arm 16 is inclined by θ ° with respect to the line segment OQ and is parallel to the line segment PQ. The orientation flat f is orthogonal to the line segment OQ.

From this state, the arm support 17 is advanced from the original position toward the processing tray 8 along the rail 15 by a distance corresponding to the distance PQ. As a result, the arm 16
The center of the wafer W placed on the processing tray 8 is
10 is moved toward the center Q of FIG. 10 and is conveyed to the position shown by the chain double-dashed line in the figure with the orientation flat f orthogonal to the line segment OQ. After that, the stage 11 is lowered and the wafer W on the arm 16 is placed on the processing tray 8. At that time, the center P of the wafer W coincides with the center Q of the processing tray 8 and is not eccentric, and the orientation flat f has a line segment O.
It is set on the processing tray 8 in a state where there is no rotational deviation orthogonal to Q.

When the wafer W is placed on the processing tray 8 in this manner, the arm support 17 and the stage 11 are returned to their original positions. Thus, the transfer of one wafer W is completed. Next, the transfer robot 6 moves along the rail 7 to a position corresponding to the carrier 5 on the right side of FIG. 3, and transfers one wafer W to be transferred next in the carrier 5 adjusted up and down by that time. To start. Thereafter, the transfer robot 6 alternately moves between the carriers 5, and sequentially transfers the accommodated wafers W in the respective carriers 5 to the corresponding processing trays 8.

As described above in detail, according to the present embodiment, since the distance sensors 20 and 21 are installed on both sides of the transfer path of the arm 16 so as to detect the outer peripheral surface of the wafer W placed on the arm 16, The displacement of the wafer W with respect to the arm 16 can be detected on the transfer route by the distance sensors 20 and 21. Therefore, the carrier 5 and the processing tray 8
Since it is not necessary to transfer the wafer W to the outside of the transfer path that linearly connects and, the transfer time can be shortened accordingly. Further, the wafer W is connected to the distance sensors 20, 21.
Since the detection is performed during the transfer movement, the transfer time can be further shortened.

Further, the center deviation and the rotation deviation of the wafer W with respect to the arm 16 are surely corrected during the transfer by the transfer robot 6, so that the wafer W is processed by the processing tray 8.
On the other hand, it can be placed with high positional accuracy without center deviation and rotation deviation. As a result, the wafer W can always be processed in the same state (position), and stable processing can be performed.

Further, since the mounting position of the wafer W is corrected by only two movement elements, that is, the rotational movement of the stage 11 and the linear movement of the arm support 17, the movement of the transfer robot 6 for correction is performed. It is simple and the mechanism can be constructed with a relatively simple structure. As a result, since the structure is relatively simple, troubles are unlikely to occur.

Since the distance sensors 20 and 21 are installed so as not to detect the detection light (or detection wave) of the other party from each other, the distance sensors 20 and 21 detect from the other party when detecting the outer peripheral surface of the wafer W. False detection of light (or detection wave) can be prevented. As a result, the wafer W can be set on the processing tray 8 with high positional accuracy.

The present invention is not limited to the above embodiments, but can be modified as follows, for example, within the scope of the invention. (1) The arm support 17 can be moved not only in the X-axis direction along the rail 15 but also in the Y-axis direction orthogonal to the rail 15, and the arm 16 can be moved along the X-axis with respect to the wafer W once placed on the table 19. Alternatively, the center deviation of the wafer W may be corrected by correcting the position in the Y-axis direction.
In this case, the rotation deviation of the wafer W may be performed by the rotation of the stage 11.

(2) Although the table 19 is fixed integrally with the robot body 9 in the above embodiment, the table 19 may be rotatable with respect to the arm 16. In this case, the rotation displacement of the wafer W with respect to the arm 16 can be corrected by rotating the table 19 on which the wafer W is temporarily placed.

(3) Instead of the arm support 17, a transfer belt which can be rotated and moved up and down with respect to the wafer W, like the arm support 17, may be used. (4) The arm 16 is provided with a rotatable stage portion, and the wafer W is not temporarily placed on the table 19 and
The wafer W mounted on the stage part may be configured to correct the rotational deviation while being mounted on the arm 16 by the rotation of the stage part. According to this configuration, since it is not necessary to temporarily place the wafer W on the table 19, the transfer time can be further shortened.

(5) Regardless of the distance sensors 20 and 21, one reflection type sensor 55 as described in the prior art is installed on the stage 11 to detect the orientation flat f of the wafer W. It may be configured to detect the rotation deviation of the wafer W. In this case, the eccentricity of the wafer W may be detected by the distance sensors 20 and 21, or may be configured to be performed by a plurality of reflective sensors installed at positions corresponding to the outer circumference of the wafer W.

[0044]

As described in detail above, the first to third aspects of the invention are described.
According to the invention described in (1), there is an excellent effect that the center deviation and the rotation deviation of the wafer with respect to the mounting portion of the transfer means can be corrected in a non-contact manner and on the transfer path.

Further, according to the invention of claim 4, the semiconductor wafer in the carrier placed on the carrier placing portion is conveyed by the conveying device and placed on the wafer placing portion with high positional accuracy. The semiconductor wafer can be stably processed by the wafer processing means.

According to the invention described in claim 5, since the semiconductor wafer is detected by the distance sensor during the movement on the transfer path, the transfer time can be shortened. According to the invention of claim 6, by detecting the outer circumference of the semiconductor wafer with the distance sensor, the deviation amount between the virtual center of the mounting portion and the center point of the semiconductor wafer mounted on the mounting portion is determined. It can be calculated.

According to the seventh aspect of the invention, by detecting the outer circumference of the semiconductor wafer with the distance sensor, it is possible to detect the rotational deviation of the semiconductor wafer with respect to the mounting portion, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is a plan view of a transfer robot according to an embodiment.

FIG. 2 is a side view of a transfer robot.

FIG. 3 is a partially cutaway plan view of the wafer processing apparatus.

FIG. 4 is a plan view of a wafer placed on an arm.

FIG. 5 is graph data obtained from a distance sensor.

FIG. 6 is graph data obtained from a distance sensor.

FIG. 7 is an operation diagram of the transfer robot.

FIG. 8 is an operation diagram of the transfer robot.

FIG. 9 is an operation diagram of the transfer robot.

FIG. 10 is an operation diagram of the transfer robot.

FIG. 11 is a partially cutaway plan view of a conventional wafer processing apparatus.

FIG. 12 is a plan view of a conventional alignment unit.

[Explanation of symbols]

2 Wafer Processing Apparatus Constituting Wafer Processing Means 3 Processing Chamber Constituting Wafer Processing Means 4 Load Lock Chamber Constituting Wafer Processing Means 5 Carrier 5a Carrier Placement Section 6 Transfer Robot as Transfer Means 8 Wafer Placement Section Processing tray 11 Stage 13 Motor constituting displacement correcting means 14 Motor constituting displacement correcting means 16 Arm as mounting portion 19 Table 20, 21 Distance sensor constituting displacement amount detecting means and displacement angle detecting means W Wafer O Virtual center f Orientation flat MC Microcomputer as displacement means and displacement angle detection means, and also as calculation means P Center point B Axis center line

Claims (7)

[Claims] 1. A transfer means (6) comprising a mounting part (16) for mounting a semiconductor wafer (W), and moving a predetermined transfer path to transfer the semiconductor wafer (W) from an initial position to a target position. And the deviation amount between the virtual center (O) set in the placement unit (16) and the center point (P) of the semiconductor wafer (W) placed on the placement unit (16) is calculated as above. A deviation amount detecting means (20, 21, MC) for detecting the semiconductor wafer (W) on the transfer path in a non-contact manner, and a reference line (B) set in the placing part (16). The deviation angle between the reference line (f) set on the semiconductor wafer (W) mounted on the mounting part (16) is not determined with respect to the semiconductor wafer (W) on the transfer path. Deviation angle detection means (20, 21, MC) for detecting by contact, the deviation amount detection means (20, 21, MC) and deviation The mounting table (16) capable of mounting the semiconductor wafer (W) at the target position based on the deviation amount and the deviation angle detected by the angle detecting means (20, 21, MC) without center deviation and rotation deviation. ) A semiconductor wafer transfer device including position correction means (11, 13, MC) for correcting the mounting position of the upper semiconductor wafer (W). 2. A transfer means (6) comprising a mounting part (16) for mounting the semiconductor wafer (W) and moving the predetermined transfer path to transfer the semiconductor wafer (W) from an initial position to a target position. The semiconductor wafer (W) at the initial position.
A distance sensor (20, 21) for detecting a distance to a predetermined portion of the semiconductor wafer (W) in the process of the transfer means (6) mounted on 6) moving from the initial position to the target position.
And an amount of deviation between the virtual center (O) set in the mounting part (16) based on the detection signal from the distance sensor (20, 21) and the center point (P) of the semiconductor wafer (W). Displacement amount calculation means (MC) for calculating the reference value (B) and the semiconductor wafer (W) set in the mounting part (16) based on the detection signal from the distance sensor (20, 21). Deviation angle calculating means (MC) for calculating the deviation angle with respect to the reference line (f) set in the above, and the deviation amount detecting means (MC) and the deviation angle detecting means (M).
The semiconductor wafer (W) can be placed on the target position without center deviation and rotation deviation based on the deviation amount and the deviation angle detected by C). And a position correcting means (11, 13, MC) for correcting the mounting position of the semiconductor wafer. 3. A stage (11) which is rotatable while moving along a transport path set from an initial position to a target position.
The semiconductor wafer (W) mounted on the mounting part (16) in the process of mounting the semiconductor wafer (W) and moving the mounting part (16) from the initial position to the target position. ) A predetermined portion of the distance sensor (20,
21), and based on the detection signal from the distance sensor (20, 21), the virtual center (O) set in the placement part (16) and the placement part (16) are placed. The amount of deviation from the center point (P) of the semiconductor wafer (16), the reference line (B) set on the placing unit (16), and the placing unit (16).
The rotation deviation angle of the semiconductor wafer (W) is calculated by the calculating means (MC) on the basis of the deviation angle from the reference line (f) set on the semiconductor wafer (W) placed on the upper surface of the semiconductor wafer (W). (1
6) The semiconductor wafer (W) to be mounted on the table (19)
Once temporarily placed on the semiconductor wafer, the semiconductor wafer is subjected to rotation correction and eccentricity correction of the mounting state of the semiconductor wafer (W) based on the deviation amount and the deviation angle detected by the computing means (MC). A method of transporting a semiconductor wafer, wherein (W) is placed on the target position without center deviation and rotation deviation. 4. A carrier mounting part (5a) on which a carrier (5) accommodating the semiconductor wafer (W) is mounted so that the semiconductor wafer (W) is located at the initial position, and the target position. A wafer mounting part (8) arranged in
Wafer processing means (2, 3,) for performing a predetermined process on the semiconductor wafer (W) mounted on the wafer mounting part (8).
4) and a semiconductor wafer transfer device according to claim 1. 5. The distance sensor (20, 21) according to claim 2, wherein the semiconductor wafer (W) being conveyed and being moved is arranged on both sides of a conveyance path of the semiconductor wafer (W) so as to detect the semiconductor wafer (W). A semiconductor wafer transfer device as described above. 6. The displacement amount computing device (MC) obtains position coordinates of a plurality of points on the outer circumference of a semiconductor wafer (W) based on a detection signal from the distance sensor (20, 21), and the position coordinates are calculated. An approximate expression of a circle representing the outer circumference of the semiconductor wafer (W) is obtained based on the above equation, and the virtual center (O) of the mounting part (16) and the semiconductor wafer mounted on the mounting part (16) ( The semiconductor wafer transfer apparatus according to claim 2, wherein a deviation amount of W) from a center point (P) is calculated. 7. The displacement angle computing device (MC) obtains position coordinates of a plurality of points on the outer periphery of the semiconductor wafer (W) based on a detection signal from the distance sensor (20, 21), and the position coordinates are calculated. A linear region having a constant inclination is obtained on the basis of the inclination of the orientation flat (f) of the semiconductor wafer (W) with respect to the reference line (B) set in the mounting unit (16) based on the inclination of the linear region. The semiconductor wafer transfer device according to claim 2, wherein the position angle is calculated.