JP2012216752A - Load lock module, wafer processing system, and wafer processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a load lock module which detects wafer's warpage caused by cooling and prevents dropping or damage of the wafer from occurring, and to provide a wafer processing system including the load lock module, and to provide a wafer processing method conducted in the wafer processing system.SOLUTION: A load lock module 1 includes a cooling part 12 cooling a wafer 10. The load lock module 1, including a detection part detecting warpage caused in the wafer 10 due to cooling of the cooling part 12, is provided.

Description

  The present invention relates to a load lock module, a wafer processing system, and a wafer processing method capable of adjusting a pressure between a vacuum atmosphere and an atmospheric atmosphere and cooling a wafer.

  FIG. 13 is a schematic top view showing a conventional general wafer processing system. The wafer processing system includes a load lock module 1, a load port 2, a loader module 3, a transfer module 4, and a processing module 5.

  When the wafer is loaded from outside the processing system, the wafer is placed in the load port while being accommodated in the FOUP, and is transferred from the load port 2 to the load lock module 1 by the arm 3 d provided in the loader module 3. Since the wafer processing is performed in a vacuum atmosphere, after the load lock module 1 is switched from the atmospheric pressure atmosphere to the vacuum atmosphere, the wafer is transferred to the processing module 5 by the arm 4d provided in the transfer module 4, and processed. Processing is performed. The wafer subjected to the processing is carried out of the processing system through a path opposite to that described above.

  The wafer processing performed in the processing module 5 is performed at a high temperature of about 300 ° C. to 500 ° C. Since the wafer oxidizes at high temperature and atmospheric pressure, it is necessary to cool the processed wafer before switching the load lock module 1 from the vacuum atmosphere to the atmospheric pressure atmosphere.

  Therefore, a load lock module including a cooling unit that cools the wafer inside the load lock module is disclosed (see Patent Document 1).

JP 2005-518664 A

  The wafer may be warped when cooled. If the wafer is warped, the wafer may drop from the arm provided in the loader module 3 when the wafer is unloaded from the load lock module 1, or the film applied to the wafer may be damaged. Production efficiency decreases. However, in the wafer processing system of Patent Document 1, the load lock module 1 cannot detect wafer warpage.

  The present invention has been made in view of such circumstances, a load lock module capable of detecting warpage due to cooling of the wafer and preventing the wafer from falling or breaking, a wafer processing system including the load lock module, An object of the present invention is to provide a wafer processing method performed by the wafer processing system.

A load lock module according to the present invention is a load lock module including a cooling unit for cooling a wafer, a sensor for measuring positions of a plurality of points on the outer periphery of the wafer, and a center position of a circle defined by the plurality of points Based on the center position calculation unit for calculating the distance, the distance calculation unit for calculating the distance between the calculated center position of the circle and the predetermined position on the cooling unit or the wafer, and the center position and the distance after cooling by the cooling unit And a detector for detecting the warpage of the wafer.

  According to the present invention, since the wafer warp caused by the cooling unit cooling the wafer can be detected, the conventional problem that the wafer falls or breaks during the transfer due to the wafer warp is obviated. Can be prevented.

  In the load lock module according to the present invention, the cooling unit is configured to further cool the wafer based on a measurement result of the detection unit.

  According to the present invention, it is possible to eliminate the warpage generated in the wafer by the cooling unit continuing the cooling, so that the production efficiency of the wafer can be improved.

  In the load lock module according to the present invention, the detection unit is further configured to detect a shift between a position of the wafer and a position where the wafer is to be placed on the cooling unit. .

  According to the present invention, since it is possible to detect a deviation between the position of the wafer and the position where the wafer is to be placed on the cooling unit, the wafer is dropped or damaged during conveyance due to the deviation of the wafer. We can prevent problem that we had.

  The load lock module according to the present invention further includes a table that is connected to the cooling unit and that moves the mounted wafer up and down and rotates, and the detection unit stores information on a peripheral shape of the wafer rotated by the table. It is characterized by acquiring.

  According to the present invention, the center position and the notch position of the wafer 10 can be detected by rotating the wafer with the table.

  The wafer processing system according to the present invention includes a processing module for processing a wafer, a transfer module for transferring a wafer processed by the processing module, and the above-described invention in which the wafer is carried by the transfer module. And a load lock module.

  According to the present invention, since the load lock module according to the present invention is provided in the wafer processing system, the above-described effects in the load lock module can also be achieved in the wafer processing system.

  A wafer processing system according to the present invention includes a module having an arm for placing a wafer and transporting the wafer to the load lock module, a measuring unit provided in the module and measuring the position of the placed wafer, and the measurement An arm position deviation calculation unit for calculating a deviation between the position of the wafer placed by the measurement unit and a predetermined position in the arm, and a position at which the arm moves when the wafer is transferred; The apparatus further includes a control unit that performs control based on the deviation calculated by the unit.

  According to the present invention, the deviation of the position and direction of the wafer placed on the arm is calculated, and the arm is controlled based on the deviation. Therefore, even when the positional deviation is large, the position is corrected appropriately. be able to.

  In the wafer processing system according to the present invention, the measurement unit is configured to measure the position of a marker provided at a position different from the center of the wafer, and the measurement unit measures from the center of the wafer to the marker measured by the measurement unit. An arm direction deviation calculating unit that calculates a deviation between a direction and a predetermined direction in the arm, and a rotating unit that is provided on the cooling unit and rotates a mounted wafer, and the control unit includes the rotating unit The rotation angle is controlled based on the deviation calculated by the arm direction deviation calculation unit.

  According to the present invention, since the control unit calculates the positional deviation of the wafer placed on the arm and controls the rotating unit based on the deviation, the positional deviation can be calculated together with the position. Duplicate processing can be performed at the time of calculation.

  A wafer processing method according to the present invention is a wafer processing method performed by a wafer processing system including a processing module for processing a wafer, a transfer module for transporting the wafer, and a load lock module for cooling the wafer. A processing step of processing the wafer by the processing module, a transfer step of transferring the wafer from the processing module to the load lock module by the transfer module, and a cooling step of cooling the wafer by the load lock module And a detection step of detecting warpage of the wafer by calculating a distance between a center position of a circle defined by a plurality of points on the outer periphery of the wafer and a predetermined position on the cooling unit or the wafer. Features.

  According to the present invention, since the wafer warp caused by the cooling unit cooling the wafer can be detected, the conventional problem that the wafer falls or breaks during the transfer due to the wafer warp is obviated. Can be prevented.

  The wafer processing method according to the present invention further includes a second cooling step of cooling the wafer based on the detection result of the detection step.

  According to the present invention, it is possible to eliminate the warpage generated in the wafer by the process of continuing the cooling, so that the production efficiency of the wafer can be improved.

  The wafer processing method according to the present invention further includes a step of detecting a deviation between a position of the wafer transferred by the transfer step and a position where the wafer is to be placed on the cooling unit. To do.

  According to the present invention, since it is possible to detect a deviation between the position of the wafer and the position where the wafer is to be placed on the cooling unit, the wafer is dropped or damaged during conveyance due to the deviation of the wafer. We can prevent problem that we had.

  According to the load lock module, wafer processing system and wafer processing method of the present invention, the load lock module can detect the warpage of the wafer caused by cooling the semiconductor wafer. By giving a warning, a person who monitors the wafer processing system can act appropriately, and it is possible to prevent a problem that has occurred in the past from dropping or breaking the wafer during conveyance due to warpage of the wafer.

It is a typical top view showing the wafer processing system in a 1st embodiment. It is a typical sectional side view showing the load lock module in a 1st embodiment. It is a schematic diagram showing the example of arrangement | positioning of a line sensor. It is a flowchart showing the process at the time of the control part in 1st Embodiment detecting the curvature of a wafer. It is the typical top view shown about the positional relationship of a wafer and a light-receiving part. It is a schematic diagram showing that the position of an outer periphery changes with the curvature of a wafer. It is an xy coordinate representing the virtual circle obtained by the control unit and the center position of the virtual circle. It is a flowchart showing the process at the time of the control part in 2nd Embodiment detecting the curvature of a wafer. It is a flowchart showing the process at the time of the control part in 3rd Embodiment detecting the shift | offset | difference of the position of a wafer. It is a typical sectional side view showing the load lock module in a 4th embodiment. It is a typical top view showing the wafer processing system in a 5th embodiment. It is a typical top view showing the wafer processing system in a 6th embodiment. It is a typical top view showing the conventional general wafer processing system. It is a schematic diagram of the loader module which concerns on 7th Embodiment. It is a schematic diagram which shows the state which the arm extended | stretched and refracted. It is explanatory drawing which shows the straight line computed by the least square method. It is a top view which shows the length and angle of an arm. It is a flowchart which shows the process of the control part in 7th Embodiment.

<First Embodiment>
A first embodiment will be described. FIG. 1 is a schematic top view showing a wafer processing system in the first embodiment, and FIG. 2 is a schematic sectional side view showing a load lock module 1 in the first embodiment.

  When the wafer 10 is loaded from outside the processing system, it is placed on the load port 2 while being accommodated in the FOUP, and is transferred from the load port 2 to the load lock module 1 by the loader module 3. After the inside of the load lock module 1 is switched from the atmospheric pressure atmosphere to the vacuum atmosphere, the wafer is transferred to the processing module 5 by the transfer module 4 and processed. The wafer subjected to the processing is carried out of the processing system through a path reverse to that described above. Such processing is controlled by the control unit 6 described later.

  Of the modules in the processing system, the load lock module 1 will be further described. The chamber 13 constituting the load lock module 1 is a rectangular parallelepiped sealed container. On the bottom wall inside the chamber 13, a cooling unit 12 having a cylindrical shape, a flat top surface, and a horizontal surface is provided. As an example of the size, when the diameter of the wafer 10 to be processed is 300 mm, the upper surface of the cooling unit 12 has a diameter of about 350 mm. The cooling unit 12 includes a cooling pipe 18 inside, and water is circulated in the cooling pipe 18 by a water supply pump 19. The wafer 10 is cooled by placing the wafer 10 on the cooling unit 12.

  The vacuum pump 14 provided outside the chamber 13 is connected to the inside of the chamber 13 by an exhaust pipe 16, and an open / close valve 15 is provided in the middle of the exhaust pipe 16.

A gate valve 17 a for carrying in and out the wafer 10 is provided on one side wall of the chamber 13. The gate valve 17a serves as an entrance / exit when the loader module 3 carries the wafer 10 to / from the load port 2 when opened. Further, a gate valve 17b for loading and unloading the wafer 10 is provided on another side wall of the chamber 13 facing the one side wall. The gate valve 17b serves as an entrance / exit when the transfer module 4 carries the wafer 10 into / out of the processing module 5 when opened.

  Although normally embedded in the cooling unit 12, lift pins 20 are provided that extend vertically upward according to instructions from the control unit 6 and are configured to support the wafer 10 at the tip.

  Next, the light emitting unit 11a and the light receiving unit 11b constituting the line sensor provided in the chamber 13 will be described. FIG. 3 is a schematic diagram illustrating an arrangement example of the line sensor. The light emitting unit 11a includes a light emitting element, the light receiving unit 11b is rectangular, and the length of the light receiving unit 11b is about 100 mm.

  The light receiving portions 11b, 11b, and 11b are arranged in three equal parts so that the longitudinal direction is the radial direction of the upper surface of the cooling unit 12, and are embedded in the upper surface of the cooling unit 12 so that the upper surface of the cooling unit 12 is flush. The light receiving portions 11 b, 11 b, and 11 b are provided with one ends at locations away from the outer periphery of the upper surface of the cooling portion 12 by about 10 mm in the central direction of the cooling portion 12. Therefore, when the wafer 10 is arranged so that the center of the wafer 10 and the center of the upper surface of the cooling unit 12 coincide with each other, the vicinity of the center in the longitudinal direction of the light receiving unit 11 b overlaps with a point on the outer periphery of the wafer 10. The light emitting units 11a, 11a, and 11a are provided on the upper wall of the chamber 13 directly above the light receiving units 11b, 11b, and 11b. The light emitting units 11a, 11a, and 11a emit light according to instructions from the control unit 6 described later, and the light receiving units 11b, 11b, and 11b receive the light.

  In the processing system according to the present embodiment, each module 1 to 5 transports the wafer 10, opens and closes a gate valve for loading and unloading the wafer 10 in each module, and maintains or releases the pressure in the module. The controller 6 is provided to instruct the cooling of the wafer 10 and the detection of the warpage of the wafer 10.

  When the wafer 10 is loaded into the load port 2 from the outside of the processing system, the control unit 6 is provided in the loader module 3 and unloads the wafer 10 from the load port 2 by the arm 3d for carrying the wafer. When the wafer 10 is unloaded from the load port 2 by the arm 3 d, the gate valve 17 a is opened and the wafer 10 is placed on the cooling unit 12. When the wafer 10 is placed, the gate valve 17a is closed, and on the other hand, the vacuum pump 14 is operated to open the on-off valve 15, thereby evacuating the chamber 13 through the exhaust pipe 16 to create a vacuum atmosphere. When the inside of the chamber 13 is brought into a vacuum atmosphere, the gate valve 17b and the gate valve 5c that is the carry-in / out port of the wafer 10 in the transfer module 4 that is a sealed container are opened, and an arm for transferring the wafer 10 provided in the transfer module 4 The wafer 10 is carried out to the processing module 5 which is an airtight container by 4d.

  The transfer module 4 and the processing module 5 are provided with a vacuum pump (not shown) outside the module to exhaust the inside of the module, and always maintain a vacuum atmosphere.

  When the control unit 6 unloads the wafer 10 from the load lock module 1 by the arm 4d, the control unit 6 closes the gate valve 17b. On the other hand, the gate valve 5c of the processing module 5 is opened, and the wafer 10 is placed at an appropriate location in the processing module 5 by the arm 4d. The controller 6 closes the gate valve 5 c and causes the processing module 5 to process the wafer 10. When the processing of the wafer 10 is completed, the gate valve 5c is opened, and the wafer 10 is unloaded from the processing module 5 by the arm 4d. On the other hand, the gate valve 17b is opened, and the wafer 10 is placed on the cooling unit 12 by the arm 4d.

  When the wafer 10 is placed, the controller 6 closes the gate valve 17b, and cools the wafer 10 for a certain time while switching the chamber 13 from the vacuum atmosphere to the air atmosphere. When a certain time has elapsed, the wafer 10 is lifted from the upper surface of the cooling unit 12 by the lift pins 20 to cause the light emitting unit 11a to emit light, and detection of warpage of the wafer 10 described later is started. The lift pin 20 is normally embedded in the cooling unit 12, but is configured to extend vertically upward according to an instruction from the control unit 6. When the detection of the warp is completed, the gate valve 17a is opened, and the wafer 10 is carried out to the load port 2 by the arm 3d.

  Next, the detection of the warpage of the wafer 10 performed by the control unit 6 will be described. FIG. 4 is a flowchart showing processing when the control unit 6 detects warpage of the wafer 10 in the first embodiment. Note that the position of the wafer 10 before cooling in this embodiment is a position where the center of the wafer 10 and the center of the cooling unit 12 coincide.

  The control unit 6 places the wafer 10 on the lift pins 20 on the cooling unit 12 and starts cooling the wafer 10 (step S11). The wafer 10 is lifted from the upper surface of the cooling unit 12 by the lift pins 20 to finish cooling for a predetermined time (step S12). The control unit 6 causes the light emitting units 11a, 11a, and 11a to emit light while supporting the wafer 10 (step S13).

  The control unit 6 acquires information on how much light emitted from the light emitting units 11a, 11a, and 11a has been received from the light receiving units 11b, 11b, and 11b (step S14).

  Based on the amount of light received by the light receiving units 11b, 11b, and 11b, the control unit 6 has three points that overlap when the positions where the light receiving units 11b, 11b, and 11b are provided and the outer periphery of the wafer 10 are viewed from directly above. The position is measured (step S15).

  A method of calculating the positions of three points that overlap when the positions where the light receiving portions 11b, 11b, and 11b are provided and the outer periphery of the wafer 10 will be described. FIG. 5 is a schematic top view showing the positional relationship between the wafer 10 and the light receiving portions 11b, 11b, and 11b.

  The control unit 6 performs the following calculation assuming an xy coordinate system in which the center position of the upper surface of the cooling unit 12 is the origin and the longitudinal direction of one light receiving unit 11b is aligned with the y axis. Let α be the distance between the origin and the end of the light receiving portion 11b closer to the origin, and let β be the length in the longitudinal direction of the light receiving portion 11b. In the control unit 6, position information on the center of the upper surface of the cooling unit 12, which is the origin, a distance α, and a length β are set in advance. Because of the positional relationship between the wafer 10 and the light receiving portion 11b in FIG. 5, a part of the light receiving portion 11b is blocked by the wafer 10 and cannot receive the light emitted from the light emitting portion 11a.

It is assumed that the light receiving unit 11b can receive light of the light amount L from the light emitted from the light emitting unit 11a unless it is shielded from light. In this case, when the light receiving unit 11b receives (1-m ₁ ) L light, the portion of the length m ₁ β in the longitudinal direction of the light receiving unit 11b is shielded by the wafer 10. At this time, the position of the point where the portion where the light receiving portion 11b is provided and the outer periphery of the wafer 10 overlap when viewed from directly above is represented by (1).

As described above, since the light receiving portions 11b, 11b, and 11b are arranged in three equal parts so that the longitudinal direction is the radial direction of the upper surface of the cooling portion 12, one longitudinal direction of the light receiving portion 11b is made to coincide with the y-axis direction. The other light receiving portion 11b has a longitudinal direction rotated by 120 ° counterclockwise from the positive direction of the y-axis. The other light receiving portion 11b has a longitudinal direction rotated by 120 ° clockwise from the positive direction of the y-axis.

Then, when the other light receiving portions 11b and 11b received (1-m ₂ ) L and (1-m ₃ ) L, respectively, the portion where the light receiving portion 11b was provided and the outer periphery of the wafer 10 were viewed from directly above. The positions of the overlapping points are represented by (2) and (3), respectively.

Further, the control unit 6 calculates the center position of the virtual circle passing through the three points obtained by the equations (1) to (3) (step S16). The control unit 6 can calculate the coordinates (x ₀ , y ₀ ) of the center position of the virtual circle and the radius r of the virtual circle defined by the following equations (4) to (6).

  FIG. 6 is a schematic diagram showing that the position of the outer periphery changes due to the warpage of the wafer 10. When the wafer 10 changes from a state without warping as shown in FIG. 6A to a state warped as shown in FIG. 6B, the position of the outer periphery in the xy coordinate system also changes. The wafer 10 does not necessarily warp in a concave shape as shown in FIG. 6B, and may warp in a convex shape.

Here, the wafer 10 is warped because the temperature is not uniform within the surface of the wafer 10. When the wafer 10 is cooled, the temperature near the outer periphery tends to be lower than that near the center. Therefore, when the wafer 10 is warped, it occurs in the vicinity of the outer periphery, but normally, a part having a low temperature is locally formed in a part of the wafer 10, so that a part in the vicinity of the outer periphery of the wafer 10 is compared with other parts in the vicinity of the outer periphery. Large warping occurs. That is, when the wafer 10 is warped, a large position change occurs only in a part near the outer periphery of the wafer 10, and the portion where the light receiving portion 11 b is provided overlaps the outer periphery of the wafer 10 when viewed from directly above. Since the change in the position of the point is biased, it can be considered that the center position (x ₀ , y ₀ ) of the virtual circle is farther from the origin as the warp increases.

FIG. 7 shows xy coordinates representing the virtual circle and the center position of the virtual circle obtained by the control unit 6. FIG. 7A shows a virtual circle passing through three points measured when the wafer 10 is not warped and the center (x ₀ , y ₀ ) of the virtual circle. When there is no warpage, in (1) to (3), m ₁ = m ₂ = m ₃ and (x ₀ , y ₀ ) coincides with the origin. On the other hand, FIG. 7B shows a virtual circle passing through three points measured when the wafer 10 is warped and the center of the virtual circle. When there is a warp, m ₁ , m ₂ , and m ₃ have different values, and (x ₀ , y ₀ ) is away from the origin.

The control unit 6 presets threshold information. The threshold value is set to a limit value that can be considered that the wafer 10 is not warped. The control unit 6 calculates a distance p ₀ between the center position of the virtual circle and the center position of the upper surface of the cooling unit 12, and determines whether the distance p ₀ is equal to or less than a threshold value (step S17). The distance p ₀ is expressed by the following equation (7).

If the control unit 6 determines that the distance p ₀ is equal to or smaller than the threshold value (YES in step S17), the process is terminated. If the control unit 6 determines that the distance p ₀ is larger than the threshold (NO in step S17), the control unit 6 issues a warning (step S18). Examples of warnings include displaying a warning text on a display device (not shown) provided outside the wafer processing system, and sounding a warning sound on a sound device (not shown) provided outside the wafer processing system. When the control unit 6 issues a warning, the process for detecting the warpage of the wafer 10 is terminated.

  In the present embodiment, the object for which the control unit 6 measures the distance from the center position of the virtual circle is not limited to the center position on the top surface of the cooling unit 12, but also the points on the top surface of the cooling unit 12 other than the center position. 10 or a predetermined position in the chamber 13 other than the cooling unit 12.

  An example of the predetermined position on the wafer 10 is the center of the wafer 10 before cooling. Normally, the wafer 10 does not warp before cooling, and even if warpage occurs due to cooling, the position of the entire wafer 10 does not move. Further, as described above, since the wafer 10 is warped near the outer periphery, the position of the center is hardly changed even if the warp occurs. Therefore, if the center position of the wafer 10 is measured before the wafer 10 is cooled, the warp can be detected by calculating the distance from the center position of the virtual circle.

  The light emitting unit 11a and the light receiving unit 11b, which are sensors for measurement, only need to be able to measure the positions of three or more points on the outer periphery of the wafer 10, and two line sensors that are longer in the longitudinal direction than the present embodiment. Two points on the outer periphery of the wafer 10 may be measured by at least one line sensor provided in a T shape or in parallel. Further, the sensor is not limited to the line sensor, and may be a two-dimensional sensor.

According to the present embodiment, the load lock module 1 can detect warpage of the wafer 10 caused by cooling. Accordingly, by giving a warning when warpage is detected, a person who monitors the wafer processing system can act appropriately, and the wafer 10 is conventionally caused to fall or break during the transfer due to the warpage of the wafer 10. Can be prevented.

<Second Embodiment>
A second embodiment will be described. In the second embodiment, when the control unit 6 detects the warpage of the wafer 10, the control unit 6 cools the wafer 10 again and detects the warpage again.

  FIG. 8 is a flowchart showing processing when the control unit 6 detects warpage of the wafer 10 in the second embodiment. Hereinafter, the same number is attached | subjected about the structure and process similar to the structure and process mentioned above, and the description is abbreviate | omitted.

  The controller 6 counts the number of times of cooling prior to cooling (step S21). When the controller 6 counts the number of times of cooling, it performs steps S11 to S16.

The controller 6 determines whether or not the distance p ₀ is less than or equal to the threshold (step S17). If it is determined that the distance p ₀ is less than or equal to the threshold (YES in step S17), the process ends.

If the control unit 6 determines that the distance p ₀ is greater than the threshold value (NO in step S17) and further determines that the number of cooling times is equal to or less than the predetermined number (YES in step S22), steps S21 and S11 are performed again. Through the process of S17. On the other hand, if it is determined that the distance p ₀ is greater than the threshold even if the number of cooling times exceeds the predetermined number (NO in step S22), a warning is given (step S18), and the process ends.

  As described above, the cause of the warpage of the wafer 10 is that the temperature is not uniform within the surface of the wafer 10. Therefore, even if the wafer 10 is warped, the temperature difference inside the wafer 10 is eliminated by cooling the wafer 10 again, and the warpage of the wafer 10 may be eliminated.

  According to the present embodiment, it is possible to eliminate the warp caused by re-cooling the wafer 10, so that the production efficiency of the wafer can be improved.

  Note that the control unit 6 does not count the number of coolings in step S21, but calculates the total time for which the wafer 10 is cooled, and determines in step S22 whether the number of coolings is equal to or less than a predetermined number. Instead of performing the determination, the determination may be made based on whether or not the total cooling time is within a predetermined time.

  The cooling time in the present embodiment may vary depending on the number of times of cooling. For example, the controller 6 may be set so that the wafer 10 is cooled for 60 seconds for the first time and 30 seconds for the second time and thereafter.

<Third Embodiment>
A third embodiment will be described. In the third embodiment, a position shift of the wafer 10 that occurs when the wafer 10 is unloaded from the processing module 5 by the arm 4d and placed on the cooling unit 12 is detected.

The controller 6 uses the arm 4d to place the wafer 10 so that the center position of the upper surface of the cooling unit 12 and the center position of the wafer 10 are essentially matched. However, when the arrangement of the wafer 10 in the processing module 5 is deviated from the original arrangement, the position of the wafer 10 may deviate from the position where it should be originally placed even when the wafer 10 is placed on the upper surface of the cooling unit 12. . Further, when the wafer 10 is unloaded from the processing module 5 by the arm 4d and loaded onto the upper surface of the cooling unit 12, the position of the wafer 10 is originally placed due to the tilt of the arm 4d or the sliding of the wafer 10 from the arm 4d. It may deviate from the position to be done. In order to cope with such a case, the position shift of the wafer 10 is detected.

  FIG. 9 is a flowchart showing a process when the control unit 6 detects a position shift of the wafer 10 in the third embodiment.

  When the control unit 6 places the wafer 10 on the upper surface of the cooling unit 12, the light emitting units 11a, 11a, and 11a emit light prior to cooling (step S31).

  The control unit 6 acquires information on the amount of light received by the light receiving units 11b, 11b, and 11b from the light receiving units 11b, 11b, and 11b (step S32).

  Based on the amount of light received by the light receiving unit 11b, the control unit 6 measures the positions of three points where the location where the light receiving units 11b, 11b, and 11b are provided and the outer periphery of the wafer 10 overlap when viewed from directly above. (Step S33).

  Further, the control unit 6 measures the center position (x1, y1) of the virtual circle passing through the three points measured in step S33 (step S34).

When the wafer 10 is placed at a position where it should be originally placed, the center of the wafer 10 coincides with the center of the upper surface of the cooling unit 12. In addition, since the measurement of deviation due to conveyance in the present embodiment is performed before the wafer 10 is cooled, the wafer 10 is not warped by cooling. Therefore, the distance p ₁ between the center position of the upper surface of the cooling unit 12 and the center position of the wafer 10 represents the deviation between the position of the wafer 10 and the position where it should be originally placed. The distance p ₁ is expressed by the following equation (8).

Control unit 6 calculates the distance p _1, the distance p ₁ determines whether a preset threshold value or less (step S35). The threshold value is set to a limit value that can eliminate the deviation of the position of the wafer 10 by correcting with the arm 4d. The control unit 6 receives the wafer 10 by the arm 4d in response to the correction instruction, and re-places the wafer 10 on the cooling unit so as to cancel the positional deviation of the wafer 10.

If the distance p ₁ is greater than the threshold (NO in step 35), the control unit 6 issues a warning (step S36) and ends the process. Examples of warnings include displaying a warning text on a display device (not shown) provided outside the wafer processing system, and sounding a warning sound on a sound device (not shown) provided outside the wafer processing system.

If the distance p1 is less than or equal to the threshold value (YES in step 35), the number of times of cooling is counted (step S21), the wafer 10 is placed on the cooling unit 12 to cool the wafer 10 (step S11), and lift pins In step S12, the wafer 10 is separated from the cooling unit 12 and the cooling is finished. The control unit 6 causes the light emitting units 11a, 11a, and 11a to emit light while the wafer 10 is supported by the lift pins 20 (step S13).

  The control unit 6 acquires information on how much light emitted from the light emitting units 11a, 11a, and 11a has been received from the light receiving units 11b, 11b, and 11b (step S14).

Based on the amount of light received by the light receiving unit 11b, the control unit 6 measures the positions of three points where the location where the light receiving units 11b, 11b, and 11b are provided and the outer periphery of the wafer 10 overlap when viewed from directly above. (Step S15). Further, the control unit 6 calculates the center position of the virtual circle passing through the three points obtained by the equations (1) to (3) (step S16). When the measured center position of the virtual circle is (x2, y2), the distance shift p ₂ of the wafer 10 due to warping is expressed by the following equation (9).

  That is, by comparing the position of the center of the wafer 10 before cooling with the position of the center of the wafer 10 after cooling, the warpage of the wafer 10 due to cooling can be detected appropriately.

If the distance p ₂ is less than or equal to the first threshold (YES in step S41), it is determined whether or not the distance p ₂ is less than or equal to the second threshold (step S42). Distance p ₂ is greater than the first threshold (NO in step S41), the cooling times to determine whether or not a predetermined number of times or less (step S22).

If the distance p ₂ is less than or equal to the second threshold (YES in step S42), the process is terminated. If the distance p ₂ is greater than the second threshold (NO in step S42), a correction instruction is given to the arm 3d (step S44), and the process is terminated.

  If the number of times of cooling is equal to or less than the predetermined number (YES in step S22), the process returns to step S21 and the number of times of cooling is counted. When the number of cooling times exceeds the predetermined number (NO in step S22), a warning is given (step S43), and the process is terminated.

  In the present embodiment, the object for which the control unit 6 measures the distance from the center position of the virtual circle is not limited to the center position on the upper surface of the cooling unit 12, but a point on the upper surface of the cooling unit 12 other than the center position or the cooling unit 12. It may be a predetermined position in the chamber 13 other than the above.

  If the position of the wafer 10 is shifted due to the transfer, the arm 10 d may not be corrected and the wafer 10 may fall if the wafer 10 is unloaded from the load lock module 1. According to the present embodiment, since the load lock module 1 detects the shift of the position of the wafer 10, the control unit 6 can cause the arm 4 d to correct the position and transfer the wafer 10. Or the person who monitors by warning can take an appropriate action. Therefore, the production efficiency of the wafer 10 is improved in the wafer processing system.

Further, according to the present embodiment, it is possible to detect a positional shift of the wafer 10 before the wafer 10 is cooled, and to detect a warp of the wafer 10 after the wafer 10 is cooled. Therefore,
It is possible to more effectively prevent the conventional problem that the wafer 10 is dropped due to the warpage of the wafer 10 during conveyance.

<Fourth embodiment>
A fourth embodiment will be described. FIG. 10 is a schematic side sectional view showing the load lock module 1 according to the fourth embodiment. In the fourth embodiment, the turntable 30 rotates the wafer 10 to measure the center position and the notch position of the wafer 10.

  A fourth embodiment will be described. The load lock module 1 according to the present embodiment includes a light emitting unit 21a such as a light emitting diode and a light receiving unit 21b such as a CCD sensor in addition to the configuration of the first embodiment. The light emitting unit 21a includes a light emitting element, and the light receiving unit 21b has a large number of light receiving elements arranged in the vertical and horizontal directions of a square. Each side is about 100 mm in length.

  The light receiving unit 21b is embedded so that the upper surface of the cooling unit 12 is flush with the light receiving unit 11b, and is provided at a position where the center of the square made of the light receiving element and the outer periphery of the cooling unit 12 are separated by about 60 mm. It is. The square of the light receiving portion 21b is provided so that the straight line passing through the center of the light receiving portion 21b and the center of the upper surface of the cooling portion 12 is parallel to the two sides of the square. The light emitting unit 21a is provided on the upper wall of the chamber 13 just above the light receiving unit 21b.

  Further, the load lock module 1 according to the present embodiment is provided with a rotating shaft 31 having a central axis that passes through the center of the cooling unit 12 and coincides with the cooling unit 12.

  The cooling unit 12 includes a disk-shaped turntable 30 whose upper surface is horizontal. The turntable 30 has a size that does not block the light received by the light receiving unit 21b. An example of the size is about 150 mm in diameter. The turntable 30 is normally embedded in the upper surface of the cooling unit 12 so that the upper surface of the cooling unit 12 is flush with the center of the turntable 30. The center of the lower surface and the upper end of the rotating shaft 31 are connected.

  A lower portion of the rotating shaft 31 is supported by a support base 32 provided inside the cooling unit 12. The rotating shaft 31 is connected to a motor 33 provided inside the support base 32, and is configured such that the rotating shaft 31 rotates and the turntable 30 rotates when the motor 33 is actuated by an instruction from the control unit 6. . Further, the motor 33 is configured to raise and lower the turntable 30 from a level flush with the cooling unit 12 to a predetermined height as shown in FIG.

  In measuring the outer periphery of the wafer 10, the wafer 10 must be rotated so that the outer periphery of the wafer 10 can be measured by the light receiving unit 21b. However, since the cooling pipe 18 is provided in the cooling unit 12, it is difficult to rotate the cooling unit 12 itself. Accordingly, the wafer 10 is rotated by the turntable 30.

  When the unprocessed wafer 10 is placed on the upper surface of the cooling unit 12 by the arm 3d of the loader module 3, the control unit 6 raises the turntable 30 and rotates it at a constant speed, and the atmospheric pressure in the chamber 13 is increased. Change from atmosphere to vacuum.

  The light emitting unit 21a emits light continuously while the wafer 10 rotates, and the light receiving unit 21b including a large number of light receiving elements receives the light. Since the wafer 10 is circular, when the position of the wafer 10 is not displaced, the light receiving unit 21b receives the light from the same light receiving element regardless of the rotation angle of the turntable 30 and shields it. On the other hand, when the position of the wafer 10 is deviated, there is a portion in the light receiving portion 21b that receives light or blocks light depending on the rotation angle of the turntable 30.

The control unit 6 acquires information on the peripheral shape (profile) of the wafer 10 by the light receiving unit 21 b while rotating the wafer 10 by the turntable 30. Then, the eccentric amount and the eccentric direction of the wafer 10 from the center of the turntable 30 are obtained based on the acquired information, and the notch position of the wafer 10 is obtained based on the information related to the peripheral shape of the wafer 10. Further, the turntable 30 is rotated by a predetermined amount to perform alignment in the direction of the notch position with respect to the arm 4d.

  When the notch position is aligned, the control unit 6 instructs the arm 4d to be corrected based on the eccentric amount and the eccentric direction of the wafer 10 when the wafer 10 is unloaded from the load lock module 1 by the arm 4d.

  Further, as described above, the load lock module 1 according to the present embodiment detects the warpage of the wafer 10 or the displacement of the wafer 10 due to the conveyance by the light emitting unit 11a and the light receiving unit 11b.

  According to the present embodiment, the center position and the notch position of the wafer 10 before processing can be detected by the area sensor, and appropriate correction or warning can be performed. Further, since the center position and the notch position of the wafer 10 can be detected in parallel with the process of changing the load lock module 1 from the air atmosphere to the vacuum atmosphere, the loader module is maintained while maintaining the production efficiency of the wafer 10. The wafer 10 can be carried into the transfer module 4 from 3.

<Fifth embodiment>
A fifth embodiment will be described. FIG. 11 is a schematic top view showing a wafer processing system in the fifth embodiment. The wafer processing system in the present embodiment uses one load lock module for the wafer 10 before the processing and two load lock modules for the wafer 10 after the processing.

  Since it takes time to cool the wafer 10, the load lock module 1 b requires more time for processing than the load lock module 1 a. The wafer processing system in the present embodiment facilitates the production process by using two load lock modules for the wafer 10 before the processing and two for the wafer 10 after the processing. Production efficiency can be improved.

  The processing system in the present embodiment includes load lock modules 1a, 1b, and 1b, and the wafer 10 before processing is processed by using the load lock module 1a including the wafer 10 light emitting unit 21a and the light receiving unit 21b. For the subsequent wafer 10, a load lock module 1b including a light emitting unit 11a and a light receiving unit 11b is used. However, when the process of the processed wafer 10 is delayed in view of the production status of the wafer 10, the load lock module 1a may be used for the processed wafer 10.

  According to the present embodiment, the production process is smoothed, and the light emitting unit 21a and the light receiving unit 21b are used for the wafer 10 before processing, and the light emitting unit 11a and the light receiving unit 11b are used for the wafer 10 after processing. Since the above-described measurement is performed, an extra configuration is not required for performing the necessary measurement, and the cost can be reduced.

  The number of the load lock modules 1a and 1b in the wafer processing system according to the present embodiment is not limited as long as the load lock module 1b is larger than the load lock module 1a.

<Sixth Embodiment>
A sixth embodiment will be described. FIG. 12 is a schematic top view showing a wafer processing system in the sixth embodiment. The processing system in the present embodiment is provided with three or more load lock modules 1c, 1c, and 1c including the light emitting unit 11a and the light receiving unit 11b, and the light emitting unit 21a and the light receiving unit 21b.

  It is normal to use one for the wafer 10 before the processing and two for the wafer 10 after the processing. For example, when the process of the wafer 10 after the processing is delayed, all three are processed. It can also be used for the wafer 10 after processing.

  The load lock module 1c according to the present embodiment uses the wafer 10 before the processing or after the processing in which the production process is stagnant in view of the state of the production process of the wafer 10 to facilitate the production process. Thus, the production efficiency of the wafer 10 can be improved.

  The number of load lock modules 1c in the wafer processing system according to the present embodiment is not limited as long as it is 3 or more.

<Seventh embodiment>
A seventh embodiment will be described. In the present embodiment, the deviation of the position and direction of the wafer 10 placed on the arm 3d is calculated from an image obtained by photographing the wafer 10, and the arm 3d and the turntable 30 are controlled based on the deviation.

  The wafer 10 has a property of being easily cleaved, that is, easily cracked in a specific direction from a crystal direction in a plane, and the wafer 10 is divided by utilizing this cleaving property when dividing the wafer 10 into a final product. Accordingly, the processing module 5 performs processing such as cleaning, film formation, etching, exposure, and the like, and the direction of the wafer 10 must be constant along with the position of the wafer 10 when performing such processing.

  Here, when the wafer 10 is transferred from the load port 2 to the wafer load lock module 1 by the arm 3d in the loader module 3, it is assumed that the wafer 10 is placed in a predetermined position and direction in the arm 3d. . However, the position or the direction may be shifted in the process until the wafer 10 is transferred to the load port 2 or in the process of transferring the wafer 10 by the arm 3d.

  In particular, when the position shift of the wafer 10 is large, when the wafer 10 is transferred to the load lock module 1 as it is by the load port 2, the wafer 10 contacts the gate valve 17a which is a loading port of the load lock module 1, and the position of the wafer 10 further shifts. Or the wafer 10 falls or breaks.

  As a means for solving such a problem, it is difficult to enlarge the gate valve 17a. In order to improve the processing capability of the wafer processing system, it is necessary to adjust the air pressure in the load lock module 1 in a short time, so that it is desirable that the load lock module 1 has a small capacity, and accordingly, the gate It is desirable to design the valve 17a as small as possible.

  Therefore, correcting the positional deviation of the wafer 10 before the wafer 10 is loaded into the load lock module 1 can be cited as a solution. In the present embodiment, the control unit 6 calculates a deviation in the position and direction of the wafer 10 placed on the arm 3d, and controls the arm 3d and the turntable 30 based on the deviation. Further, a deviation in direction is calculated together with a deviation in position, and control is performed so that the turntable 30 corrects the deviation in direction.

  FIG. 14 is a schematic diagram showing a loader module 3 according to the seventh embodiment. The loader module 3 includes an arm 3d on a machine base 3e whose upper surface is horizontal and flat. The cylindrical drive unit 41 in the arm 3d is embedded in the machine base 3e so as to be flush with the upper surface of the machine base 3e. Further, the rod-shaped first arm portion 43 has one end in the longitudinal direction located near the center of the upper surface of the drive device portion 41. Near one end, one end of the first rotating portion 42 extending in the vertical direction extends from the drive device portion 41 and is embedded in the first arm portion 43. Near the multi-end of the first rotating part 42 is connected to a motor (not shown) provided in the machine base 3e, and the motor rotates the first rotating part 42 in the horizontal direction.

  A second rotating portion 44 is provided near the other end in the longitudinal direction of the first arm portion 43. The second rotating portion 44 has a columnar shape with the vertical direction as the longitudinal direction, the lower portion is embedded in the first arm portion 43, and the upper portion is embedded in the vicinity of one end in the longitudinal direction of the rectangular parallelepiped second arm portion 45. . As the second rotating unit 44 rotates in the circumferential direction according to an instruction from the control unit 6, the second arm unit 45 rotates and moves in the horizontal direction.

  Near the other end in the longitudinal direction of the second arm portion 45, a pick 46 having a flat upper surface and a horizontal arrangement is provided. When the wafer 10 is transferred, the arm unit 3d is bent and stretched by placing the wafer 10 on the pick 46 and rotating the first rotating unit 42 and the second rotating unit 44.

  Further, the drive unit 41 is provided with a rod-like support portion 47 that extends in the vertical direction and has a tip bent at a right angle, and a photographing portion 48 is fixed to the tip. The support 47 may be provided in any one of the loader modules 3. For example, it may be fixed to the drive unit 41 and may rotate in the same manner as the first rotating unit 42. Moreover, the support part 47 may be fixed to the 1st arm part 43, and may be fixed to the machine base 3e. The photographing unit 48 is a CCD camera, for example, and is fixed so as to photograph the lower part. A light emitting unit 49 is fixed at a position adjacent to the photographing unit 48 and emits light downward.

  FIG. 15 is a schematic diagram showing a state where the arm 3d is extended and refracted, FIG. 15A shows a state where the arm 3d is refracted, and FIG. 15B shows a state where the arm 3d is extended. The stretched and refracted state is an example, and when the arm 3d is stretched, the first arm portion 43 and the second arm portion 45 do not have to be linear and may have a predetermined angle. Even in the refracted state, it is sufficient that the first arm portion 43 and the second arm portion 45 form a predetermined angle. When the arm 3d unloads the wafer 10 from the load port 2, the arm 3d rotates the second rotating unit 44 so as to extend the arm 3d. Thereafter, the second rotating unit 44 is rotated to refract the arm 3d, and then the first rotating unit 42 is rotated by a predetermined angle to move the wafer 10. Thereafter, the second rotating unit 44 is rotated again to extend the arm 3 d, and the wafer 10 is loaded into the load lock module 1. The imaging unit 48 is fixed at a position where the entire wafer 10 can be imaged when the arm 3d is refracted.

  When the wafer 10 is placed on the pick 46 and transported to the arm 3d, the image of the wafer 10 is imaged by the imaging unit 48 when the second rotating unit 44 is rotated and the arm 3d is refracted.

  The position shift of the wafer 10 is calculated by calculating the shift between the center position of the wafer 10 and the reference center position from the image captured by the image capturing unit 48. On the other hand, in the wafer 10 according to the present embodiment, a V-shaped notch that is carved about several millimeters deep from the outer periphery to the center direction is a position where the direction from the center of the wafer 10 forms a predetermined angle with respect to the crystal direction. The deviation of the direction is calculated by calculating the deviation between the direction from the center of the wafer 10 to the point corresponding to the deepest part of the notch and the reference direction.

Therefore, it is necessary to accurately set the center position when the wafer 10 is not displaced, but the arm 3d may be displaced due to repeated use. Therefore, the control unit 6 appropriately sets a reference center position that is the center position of the wafer 10 when there is no deviation. The controller 6 causes the photographing unit 48 to photograph the pick 46 at a predetermined position prior to photographing the image of the wafer 10. The control unit 6 calculates the center position based on the position of a predetermined location of the pick 46 in the image captured by the imaging unit 48. The calculated center position is set as the origin in the xy coordinate system.

  The light emitting unit 49 emits light in accordance with the timing when the photographing unit 48 captures an image. As a result, the brightness of the photographed image is different between the portion corresponding to the wafer 10 and the other portion. The control unit 6 measures the position of the point corresponding to the periphery of the wafer 10 by measuring the position of the point having a large luminance difference from the position of the adjacent point. For the point whose position is to be measured, a part of all the points in the vicinity is selected. One point determines the number and interval of points to be selected so as to correspond to the notch portion of the wafer 10, and for example, several tens to several hundred points are selected.

  If the wafer 10 is assumed to be a perfect circle, the center position of the wafer 10 can be calculated by measuring the positions of three or more points on the periphery of the wafer 10. However, when the wafer 10 is provided with a notch, if the center position is calculated using a point corresponding to the notch as one of the points corresponding to the periphery of the wafer 10, an incorrect center position is calculated. Accordingly, the center position is calculated by a combination of various three points among the positions of the points corresponding to the periphery of the wafer 10 once obtained. Among the calculation results, when the coordinates of the center position differ from the average value of the other calculation results by a predetermined value or more, it is assumed that one of the three combinations is a notch portion.

  By obtaining a plurality of cases different from other calculation results by a predetermined value or more and determining the points included in any case, it is possible to detect one point of the notch portion. On the other hand, the center position of the wafer 10 can be accurately calculated by calculating the average of the center positions excluding the case where the difference differs by a predetermined value or more. A positional deviation is calculated from this center position and the previously obtained reference center position.

  Subsequently, the position of the notch is calculated. After the position of one point in the notch portion is detected, a position corresponding to the periphery of the wafer 10 in a predetermined range such that the foreground of the notch can be grasped from the one point is measured.

  The control unit 6 selects one point out of the respective points around the wafer 10 near the notch, and extracts a predetermined number of points located around the selected point. A straight line is calculated by the least square method based on the extracted positions of the points. After the calculation, the procedure of selecting a point adjacent to the selected point and calculating a straight line by the least square method based on a predetermined number of points around the selected point is repeated.

  FIG. 16 is an explanatory diagram showing a straight line calculated by the least square method. In this case, comparing FIG. 16A and FIG. 16B in FIG. 16, when all of the predetermined number of points adjacent to each other correspond to the circular portion of the wafer 10, the least square method is used when the selected point is set to the adjacent point. The change in the calculated slope of the straight line is small. However, when one end of the notch is included in a part of the predetermined number of points as shown in FIG. 16C, the change in the slope of the straight line calculated by the least square method is large compared to FIG. 16A. Similarly, when the point corresponding to the other end of the notch or the deepest part of the groove is included, the inclination changes greatly. Therefore, the inclination changes greatly at three locations, and the point corresponding to the deepest portion of the groove of the notch can be determined from the positional relationship of these three locations. The direction of the wafer 10 is calculated from the point corresponding to the deepest part of the groove of the notch and the center position of the wafer 10 that has already been obtained. The controller 6 stores information about the reference direction of the wafer 10 in advance, and calculates a deviation between the reference direction and the calculated direction of the wafer 10.

The controller 6 corrects the deviation after calculating the deviation of the position and direction of the wafer 10. Control unit 6
Before the wafer 10 is loaded into the load lock module 1, the arm 3d is temporarily kept in the vicinity of the gate valve 17a. At this time, the positional deviation is corrected.

The control unit 6 controls the angle at which the first rotating unit 42, the second rotating unit 44, and the pick 46 are rotated in order to correct the position by moving the arm 3d by the shifted position. FIG. 17 is a top view showing the length and angle of the arm 3d. The shift amount of the xy coordinates is (x ₃ , y ₃ ), the lengths of the first arm portion 43 and the second arm portion 45 are a ₁ and a _2, and the distance from the junction of the pick 46 to the center of the wafer 10 is a. ₃ , the angles of the first arm 43, the second arm 45 and the pick 46 when the arm 3d is waiting in the vicinity of the gate valve 17a when there is no correction are θ ₁ , θ ₂ and θ ₃ . In this case, the angles θ ₁ ′, θ ₂ ′, and θ ₃ ′ at which the first rotating unit 42, the second rotating unit 44, and the pick 46 rotate to correct the deviation are expressed by the following equations (10) and (11). In addition, it is calculated in consideration of various factors such as the movable range.

  The control unit 6 moves the arm 3d to correct the positional shift amount, then opens the gate valve 17a and places the wafer 10 on the cooling unit 12 in the load lock module 1.

  The load lock module 1 in the present embodiment includes a turntable 30 as in the configuration in the fourth embodiment. The control unit 6 operates the turntable 30 and rotates it by the calculated deviation in the direction to correct the deviation in the direction of the wafer 10.

  Next, processing of the control unit 6 in the present embodiment will be described. FIG. 18 is a flowchart showing the processing of the control unit 6 in the seventh embodiment. The control unit 6 rotates the second rotating unit 44 to refract the arm 3d (Step S51), and the imaging unit 48 images the pick 46 (Step S52). A reference center position is calculated based on the position of the picked pick 46 (step S53).

  The controller 6 extends the arm 3d (step S54), places the wafer 10 on the pick 46 (step S55), and unloads it from the load port 2 (step S56).

  The controller 6 rotates the second rotating unit 44 to refract the arm 3d (step S57), and causes the imaging unit 48 to image the wafer 10 (step S58). The position of a predetermined number of points corresponding to the periphery of the wafer 10 is measured from the photographed position (step S59), the center position of the wafer 10 is calculated (step S60), and the positional deviation from the reference center position is calculated (step S61). ). Further, the position of the point corresponding to the notch portion is measured (step S62).

The controller 6 measures the position of each point on the wafer 10 within a predetermined range centered on that one point (step S63). The position of the point corresponding to the deepest part of the groove of the notch is detected by performing the calculation by the least square method from the obtained position of each point (step S64). The direction from the center of the wafer 10 to the point corresponding to the deepest part of the groove of the notch is calculated (step S65). The direction deviation is calculated from the stored reference direction information (step S66). The control unit 6 extends the arm 3d to a position where the deviation of the position of the wafer 10 is corrected when the arm 3d is extended (step S67). Further, after placing the wafer 10 on the cooling unit 12 by the arm 3d (step S68), the control unit 6 rotates the turntable 30 by the amount of the direction deviation and corrects the direction (step S69).

  Further, when the wafer 10 is transferred from the load port 2 to the load lock module 1 by the arm 3d, the wafer 10 may be displaced in position or direction. However, since it takes a certain time for the control unit 6 to calculate the above-described deviation, there is a problem that if the calculation of the deviation is started immediately before the load 10 is loaded into the load lock module 1, the transfer of the wafer 10 is delayed. is there.

  In order to cope with such a problem, the imaging unit 48 continuously captures images of a plurality of wafers 10 while the wafer 10 is being transferred, and determines whether or not the wafer 10 has been displaced during the transfer from the plurality of images. You may do it. In this case, the control unit 6 detects the above-described position and direction deviation based on the first photographed image, and then whether or not the image has a deviation from the position and direction of the first photographed image of the wafer 10. You may make it determine. For example, this determination may be made based on whether or not the position of a point around the wafer 10 in the first image has moved.

  The wafer 10 may be provided with an orientation flat which is a linear notch instead of the notch. In this case, when the control unit 6 calculates a straight line by the least square method for a predetermined number of points as described above, the slope of the straight line changes greatly at two places. The direction of the wafer 10 is calculated based on the position of any one of the two locations.

  In addition to the notch and the orientation flat, a mark indicating the direction of the wafer 10 may be provided, and the position of the mark may be inside the wafer 10 at a predetermined distance from the center of the wafer 10. In this case, after calculating the position of the center of the wafer 10, the control unit 6 detects one point having a large luminance difference from the surrounding points at a predetermined distance from the center of the wafer 10. This detected point corresponds to a part of the sign. The position of each point having a large luminance difference from the periphery of the detected one point to the surrounding points within a predetermined range is measured, and as a result of the measurement, the position of a predetermined one of the signs is detected. The direction from the center of the wafer 10 to the predetermined point is calculated, and the deviation from the reference direction is calculated.

  Note that the loader module 3 in the present embodiment may detect the position shift in the present embodiment when the wafer 10 is unloaded from the load lock module 1 after the processing of the wafer 10 and correct the shift by the arm 3d. The arm 4d in the transfer module 4 may have the same configuration as the arm 3d in the present embodiment.

  Instead of the disc-shaped turntable 30, a lifter ring in which a hollow is provided in the disc may be used. In addition, the imaging unit 48 may include a plurality of apparatuses that image a part of the wafer 10. In this case, an image of the entire wafer is captured by combining the images of the plurality of imaging units 48.

  The arm 3d may be configured so that the mounted wafer 10 can move in the vertical direction. The loader module 3 may be provided with a plurality of arms 3d.

According to the present embodiment, in the present embodiment, the control unit 6 calculates the deviation of the position and direction of the wafer 10 placed on the arm 3d, and controls the arm 3d and the turntable 30 based on the deviation. In particular, the position can be appropriately corrected even when the position shift is large. In addition, since the deviation of the direction as well as the position is calculated, overlapping processes can be performed together when both are calculated.

  The embodiments disclosed herein are illustrative in all respects and should not be considered as restrictive. The scope of the present invention is defined not by the above-mentioned meaning but by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

1, 1a, 1b, 1c Load lock module 2 Load port 3 Loader module 3d Arm 3e Machine base 4 Transport module 5 Processing module 6 Control unit 10 Wafer
11a Light emitting part 11b Light receiving part 12 Cooling part 13 Chamber 14 Vacuum pump 15 On-off valve 16 Exhaust pipe 17a, 17b Gate valve 18 Cooling pipe 19 Water supply pump 20 Lift pin 21a Light emitting part 21b Light receiving part 30 Turntable 31 Rotating shaft 32 Support base 33 Motor 41 Drive Device Unit 42 First Rotating Unit 43 First Arm Unit 44 Second Rotating Unit 45 Second Arm Unit 46 Pick 47 Support Unit 48 Imaging Unit 49 Light Emitting Unit

Claims (10)

In a load lock module including a cooling unit for cooling a wafer,
A sensor for measuring positions of a plurality of points on the outer periphery of the wafer;
A center position calculator for calculating a center position of a circle defined by the plurality of points;
A distance calculation unit for calculating a distance between the calculated center position of the circle and a predetermined position on the cooling unit or the wafer, and detecting warpage of the wafer based on the center position and the distance after cooling by the cooling unit. A load lock module comprising a detection unit. The load lock module according to claim 1, wherein the cooling unit is configured to further cool the wafer based on a detection result of the detection unit. The load according to claim 1, wherein the detection unit is further configured to detect a deviation between the position of the wafer and a position on the cooling unit where the wafer is to be placed. Lock module. A table connected to the cooling unit and moving up and down and rotating the mounted wafer;
The load lock module according to any one of claims 1 to 3, wherein the detection unit acquires information related to a peripheral shape of the wafer rotated by the table. Processing module for processing wafers,
A wafer processing module comprising: a transfer module for transferring a wafer processed by the processing module; and the load lock module according to claim 1 in which the wafer is transferred by the transfer module. Processing system. A module having an arm on which a wafer is placed and transferred to the load lock module according to claim 1,
A measuring unit provided in the module for measuring the position of the mounted wafer;
An arm position deviation calculation unit for calculating a deviation between the position of the wafer placed by the measurement unit and a predetermined position in the arm; and a position at which the arm moves when the wafer is transferred. A wafer processing system, further comprising: a control unit that controls based on the deviation calculated by the deviation calculation unit. The measurement unit is configured to measure the position of the marker provided at a position different from the center of the wafer,
An arm direction deviation calculation unit for calculating a deviation between a direction from the center of the wafer to the marker measured by the measurement unit and a predetermined direction in the arm; and
A rotation unit provided on the cooling unit and configured to rotate the mounted wafer;
The wafer processing system according to claim 6, wherein the control unit is configured to control an angle of rotation of the rotating unit based on the deviation calculated by the arm direction deviation calculating unit. In a wafer processing method performed in a wafer processing system comprising a processing module for processing a wafer, a transfer module for transferring a wafer, and a load lock module for cooling the wafer,
A processing step of processing the wafer in the processing module;
A transfer step of transferring the wafer from the processing module to the load lock module in the transfer module;
A cooling step of cooling the wafer by the load lock module; and calculating a distance between a center position of a circle defined by a plurality of points on the outer periphery of the wafer and a predetermined position on the cooling unit or the wafer. A wafer processing method comprising a detection step of detecting warpage of the wafer. The wafer processing method according to claim 8, further comprising a second cooling step for cooling the wafer based on a detection result of the detection step. The wafer according to claim 8, further comprising a step of detecting a deviation between a position of the wafer transferred by the transfer step and a position on the cooling unit where the wafer is to be placed. Processing method.

Images