JP2012049357A - Vacuum processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an unexpected stoppage of carriage operation in a vacuum processing device, by suppressing a deviation amount of a sample position when the deviation occurs.SOLUTION: In a vacuum carriage room for carrying the sample, an acceleration of a wafer mounted on an arm produced during the carriage operation by a robot becomes maximal at the start of arm extension or the completion of arm contraction. On the detection of the sample position deviation during the carriage, if the deviation amount exceeds a prescribed threshold (tolerable value), the acceleration at the start of the robot arm extension or the completion of the contraction is decreased from A' to A, so that the deviation amount does not exceed the threshold.

Description

  The present invention relates to a vacuum processing apparatus having a plurality of processing chambers and processing a sample such as a semiconductor wafer in each processing chamber, and in particular, a transport container connected to a vacuum container and to which a substrate to be processed is transported. The present invention relates to a vacuum processing apparatus including

  In the vacuum processing apparatus as described above, when a sample such as a semiconductor wafer (hereinafter referred to as a sample) is transported, the sample is misaligned, causing a transport error or a processing failure.

  As disclosed in Japanese Patent Application Laid-Open No. 2004-228561, a positional deviation is detected with respect to the positional deviation of the sample, and the direction and amount of the positional deviation are corrected when the sample is conveyed to the processing chamber to suppress processing defects. .

JP 2007-123556 A

  However, the above-described prior art has a problem because the following points are not sufficiently considered.

  That is, in Patent Document 1, there is a limit to the amount of misalignment of the sample that can be corrected, and if the misalignment of the sample exceeds that limit, the sample transport operation must be stopped as a misalignment error. The production line of the semiconductor was stopped by the stop of the equipment that did not, and had a great influence on the production plan.

  An object of the present invention is to suppress the amount of displacement when a sample displacement occurs and to prevent an unexpected stop of the conveying operation.

  In order to achieve the above object, the vacuum processing apparatus of the present invention detects a positional deviation during conveyance in a vacuum conveyance chamber that conveys a sample, and takes a conveyance operation when the deviation amount exceeds a predetermined threshold value. The acceleration is suppressed so that the deviation amount does not exceed the threshold value.

  The vacuum processing apparatus according to the present invention includes a vacuum container in which a wafer to be processed is stored and held in a reduced pressure inside, and a plurality of vacuum containers connected to the outer periphery of the wafer in which the wafer is transported in the reduced pressure. A vacuum transfer container in which the interior communicates, and the wafer placed on the upper surface of the arm and held inside the vacuum transfer container, and the plurality of wafers are moved by the operation of extension, contraction and rotation by the arm. A robot that conveys from one of the vacuum containers to the other, and an arm that is disposed between the arm and the opening of a passage that is disposed inside the vacuum conveying container and communicates with the interior of the vacuum container. A sensor for detecting the position of the wafer placed on the substrate, and a control for adjusting the transfer operation of the robot based on information on the position of the wafer obtained from the output of the sensor The acceleration of the wafer placed on the arm generated during the transfer operation by the robot is the maximum at the start of extension of the arm or at the end of contraction, and the controller When it is determined that the deviation of the position of the wafer detected by the sensor exceeds a predetermined size, the acceleration at the start of the extension or the end of the contraction of the arm of the robot is reduced.

  In the vacuum processing apparatus of the present invention, the sensor is further positioned between the outer peripheral edge of the wafer and the opening, which is placed on the sensor with the arm contracted, on the outer peripheral edge of the wafer. The position is detected, and the acceleration is maximized before the outer edge of the wafer on the rear side in the direction of extension or contraction of the transfer is detected by the sensor.

  In the vacuum processing apparatus of the present invention, the acceleration of the wafer at the start of the extension of the arm or the end of the contraction, which is lowered by the controller, is larger than an acceleration generated during another operation of the transfer. The operation of the robot is adjusted as follows.

  The vacuum processing apparatus of the present invention is further characterized in that the wafer is held with a gap larger than a predetermined size of the gap between the wafer and the arm on the outer peripheral side of the outer peripheral edge.

  According to the present invention, even when misalignment occurs during sample processing, it is possible to prevent an unexpected stop of the apparatus by reducing the acceleration of the operation that causes the misalignment and suppressing the misalignment. The influence on the line can be suppressed.

FIG. 1 is a diagram showing the configuration of an apparatus according to the first embodiment of the present invention. FIG. 2 is a diagram showing the configuration of the vacuum transfer chamber in the first embodiment. FIG. 3 is a diagram showing the configuration of the vacuum transfer robot in the first embodiment. FIG. 4 is a diagram showing the speed of the sample during the turning operation of the vacuum transfer robot in the first embodiment. FIG. 5 shows the acceleration applied to the sample in FIG. FIG. 6 is a diagram showing the angular velocity of the arm in the expansion / contraction operation of the vacuum transfer robot in the first embodiment. FIG. 7 is a diagram showing the speed of the sample in the expansion / contraction operation of the vacuum transfer robot in the first embodiment. FIG. 8 is a diagram showing the acceleration of the sample in FIG. FIG. 9 is a diagram showing the speed of the sample during the transport operation in the first embodiment. FIG. 10 shows the acceleration applied to the sample in FIG. FIG. 11 is a diagram showing the relationship between the acceleration applied to the sample and the amount of displacement. FIG. 12 is an enlarged view of the arrangement point of the positional deviation amount in FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing an outline of the overall configuration of a vacuum processing apparatus according to a first embodiment of the present invention.

  A vacuum processing apparatus 100 according to the present embodiment shown in FIG. 1 is roughly divided into an atmospheric transfer unit 101 that transfers a sample under atmospheric pressure, and a vacuum transfer that transfers a sample under a pressure reduced from atmospheric pressure. Part 102. The vacuum transfer unit 102 includes a plurality of vacuum transfer chambers 105 and a process module 106 connected to the vacuum transfer chamber 105. The process module 106 is a module for processing a sample under a vacuum pressure.

  The atmospheric transfer unit 101 includes a substantially rectangular parallelepiped casing 103 having an atmosphere-side transfer robot 110 therein, and is attached to the front side (upper and lower sides in the figure) of the casing 103, and is a sample for processing or cleaning. Are provided with a plurality of cassette stands 111 on which the cassettes are stored.

  The vacuum transfer unit 102 includes a plurality of vacuum transfer chambers 105, a lock chamber 104 that is disposed between the vacuum transfer chamber 105-a and the atmospheric transfer unit 103, and exchanges a sample between the atmospheric side and the vacuum side, and a vacuum An intermediate chamber 107 that is disposed between the transfer chambers 105-a and 105-b and exchanges materials is provided. The vacuum transfer unit 102 is decompressed and can be maintained at a high degree of vacuum.

  In the vacuum transfer chamber 105, a vacuum transfer robot 109 that transfers a sample between the lock chamber 104 or the intermediate chamber 107 and the processing chamber in the process module 106 under vacuum is disposed at the center. A sample is placed on the arm of the vacuum transfer robot 109, and is carried in and out between the sample stage disposed in the processing chamber of the process module 106 and the sample stage in any one of the lock chamber 104 or the intermediate chamber 107. Is done. The process module 106, the lock chamber 104, the intermediate chamber 107, and the transfer chamber in the vacuum transfer chamber 105 are opened and closed by a valve 108 that can be hermetically closed and opened.

  Samples such as a plurality of semiconductor samples stored in a cassette placed on any of the cassette tables 102 are judged by a user interface device (not shown) that adjusts the operation of the vacuum processing apparatus, or the vacuum processing apparatus is installed. In response to a command from a production line host or the like, the processing is started.

  In the lock chamber 104, the valve is closed and sealed in a state where the transferred sample is stored, and the pressure is reduced to a predetermined pressure. Thereafter, the valve 108 facing the transfer chamber in the vacuum transfer chamber 105 is opened, the lock chamber 104 and the vacuum transfer chamber 105 are communicated, and the arm of the vacuum transfer robot 109 extends into the lock chamber 104. And remove the internal sample. When the sample placed on the arm on the vacuum transfer robot 109 is taken out from the cassette, the sample is carried into a evacuated processing chamber in one of the predetermined process modules 106.

  Here, when the transport destination of the sample is the upper process module 106 in the drawing, the sample is transported to the vacuum transport chamber 105-b via the intermediate chamber 107, and the vacuum transport robot in the vacuum transport chamber 105-b. 109 is carried into a processing chamber in a predetermined process module 106.

  After the sample is transferred to the processing chamber in any of the process modules 106, the valve 108 that opens and shields between the processing chamber and the vacuum transfer chamber 105 is closed to seal the processing chamber. Thereafter, a processing gas is introduced into the processing chamber, plasma is formed in the processing chamber, and the sample is processed.

  When it is detected that the processing of the sample has been completed, the valve 108 is opened, and the vacuum transfer robot 109 carries it out toward the lock chamber 104, contrary to the case where it is carried into the processing chamber. When the sample is transferred to the lock chamber 104, the valve 108 that opens and closes the passage that connects the lock chamber 104 and the vacuum transfer chamber 105 is closed to seal the inside, and the pressure in the lock chamber 104 is reduced to atmospheric pressure. Raised.

  Thereafter, the valve 108 on the atmosphere transfer chamber 103 side is opened to connect the inside of the lock chamber 104 and the atmosphere transfer chamber 103, and the sample is transferred from the lock chamber 104 to the original cassette by the atmosphere side transfer robot 110. Is returned to its original position.

  FIG. 2 is an enlarged view of the vacuum transfer chamber 105 shown in FIG. The vacuum transfer chamber 105 includes a vacuum transfer robot 109 therein and can be connected to the lock chamber 104, the intermediate chamber 107, and the process module 106 via the valve 108. Are provided with two wafer detection sensors 201 in the direction to be connected to each other.

  When transporting a sample from one module to another module, the wafer detection sensor 201 can detect the displacement of the sample in the center direction on the vacuum robot 109 when the sample is loaded from another module. .

  FIG. 3 is a diagram showing the configuration of the vacuum transfer robot 109 in FIGS. 1 and 2. The vacuum transfer robot 109 includes a hand unit 301 that holds a sample, a first arm unit 302, and a second arm unit 303. The first arm unit 302 and the second arm unit 303 control operations in synchronization. Thus, the hand unit 301 is configured to operate only in the linear direction (left-right direction in the figure). These controls are performed by a controller (not shown), and parameters such as operation speed and acceleration can be set in the controller.

  A pad 305 for holding a sample is provided on the hand unit 301, and the sample is held by a frictional force with the pad 305. In this embodiment, the sample is held by the frictional force of the pad 305, but any method for holding the sample, such as electrostatic adsorption, may be used.

  In addition, a stopper 304 that prevents the sample from dropping off is provided at the base of the hand unit 301 so that the sample can be held even when the sample slides on the hand unit 301.

  The force applied to the sample in the turning operation of the vacuum transfer robot 109 will be described with reference to FIGS. FIG. 4 shows the speed during the turning operation of the vacuum transfer robot 109, and FIG. 5 shows the acceleration during the turning operation.

  The speed of the turning operation of the vacuum transfer robot 109 is controlled by S-shaped acceleration / deceleration as shown in FIG. The acceleration at this time is as shown in FIG. 5, and the direction of the force applied to the sample is opposite to the turning direction during acceleration and deceleration due to acceleration and inertia.

  Next, the force applied to the sample in the expansion / contraction operation of the vacuum robot 109 will be described with reference to FIGS. FIG. 6 is a diagram showing the rotational angle speeds of the arm units 302 and 303 of the vacuum robot 109, FIG. 7 shows the speed of the hand unit 301 holding the sample, and FIG. 8 shows the acceleration applied to the hand unit 301. .

  Also in the expansion / contraction operation, the angular velocities of the arm portions 302 and 303 are controlled by the S-shaped acceleration / deceleration as shown in FIG.

  Here, when the angular velocity is constant, the speed of the hand unit 301 draws a cosine curve. Therefore, considering the acceleration / deceleration region, the speed of the hand unit 301 during the expansion / contraction operation is as shown in FIG. Further, since the acceleration applied to the hand unit 301 is the differential value of FIG. 7, the acceleration is as shown in FIG.

  The maximum acceleration during the expansion / contraction operation occurs at the beginning of extension and at the end of contraction, and the direction of the force applied to the sample at this time is in the direction of the root of the hand unit 301 (the left direction in FIG. 3).

  Here, it is desirable to set the maximum acceleration during expansion / contraction and turning operation so that the maximum acceleration during the expansion / contraction operation is larger. In this case, the sample displacement first occurs in the root direction of the hand 301. Even if the displacement amount increases, the sample is stopped by the stopper 304, and the sample is placed on the side surface of the vacuum transfer chamber 105 or the like. There is no interference and no sample is removed from the hand unit 301.

  Next, a method for detecting the positional deviation of the sample will be described with reference to FIGS. FIG. 9 shows the speed of the sample when the sample is transferred from the lock chamber 104 to any of the process modules 106 connected to the vacuum transfer chamber 105-a, and FIG. 10 shows the acceleration. In FIG. 9, the contraction operation indicates the root direction of the vacuum robot 109, the turning operation indicates the direction of turning from the lock chamber 104 to the process module 106, and the extending operation indicates the magnitude of the speed in the tip direction of the vacuum robot 109. .

  When the sample is transported from the lock chamber 104 to the process module 106, the sample is unloaded from the lock chamber 104 (contraction operation), moved to the position of the process module 106 (swivel operation), and the sample is loaded into the process module 106 (extension operation). It becomes the flow. The speed of the sample at this time is a combination of the expansion and contraction operation and the turning operation, so that it becomes as shown in FIG. 9, and the acceleration becomes the differential value of FIG.

  Here, the positional deviation of the sample can be detected when the sample is carried out from the lock chamber 104 (at the time of the chain line in FIG. 10) after the maximum acceleration (−αMAX) occurs. If no displacement occurs at this point, it is considered that no displacement occurs because the acceleration in the subsequent operations is the same or smaller.

  Next, a method for suppressing the amount of misalignment of the sample in this embodiment will be described with reference to FIGS. FIG. 11 is a diagram showing the relationship between the amount of positional deviation in the sample and the acceleration applied to the sample, and FIG. 12 is an enlarged view of the region where the amount of positional deviation in FIG. 11 increases.

  In the initial state (the state in which there is no deterioration of the pad 305), the relationship between the displacement amount and the acceleration draws a curve like 1101. From this state, when the pad 305 deteriorates due to a change with time or the like and the frictional force decreases, the curve 1101 changes to the curve 1102.

  An allowable value and a limit value are set in advance for the amount of positional deviation, and an acceleration A ′ at which the positional deviation occurs up to the allowable value in the initial state is determined during teaching of the apparatus, and steady operation is performed with an acceleration A smaller than that as the maximum acceleration. Make it work.

  When the deterioration of the pad 305 progresses and a positional deviation of the allowable value 701 or more is detected with the maximum acceleration A of the operation, the acceleration B obtained by subtracting the previously obtained difference between A ′ and A from the A is the maximum acceleration of the next operation. To do.

  Here, the acceleration B obtained by the above method is applied only when a sample is present on the hand unit 301, and is operated at the maximum acceleration A when no sample is present on the hand unit 301.

  As described above, even when the sample misalignment occurs, the misalignment can be suppressed by suppressing the maximization speed in the sample transport operation, and the occurrence of the transport error and the processing failure can be prevented.

DESCRIPTION OF SYMBOLS 100 Vacuum processing apparatus 101 Atmospheric transfer part 102 Vacuum transfer part 103 Standby transfer chamber 104 Lock chamber 105 Vacuum transfer chamber 106 Process module 107 Intermediate room 108 Valve 109 Vacuum transfer robot 110 Atmospheric transfer robot 111 Cassette stand 201 Wafer detection sensor 301 Hand part 302 First arm 303 Second arm 304 Stopper 305 Holding pad 1101 Curve showing the relationship between acceleration and displacement in the initial state 1102 Curve showing the relationship between acceleration and displacement in the pad deterioration state

Claims (4)

A vacuum container in which a wafer to be processed is stored and held in a decompressed interior;
A vacuum transport container in which the wafer is transported inside the decompressed interior and a plurality of the vacuum containers are connected to the outer periphery, and the interiors are in communication with each other;
A robot that is disposed inside the vacuum transfer container and holds the wafer on an upper surface of an arm, and transfers the wafer from one of the plurality of vacuum containers to the other by an extension and contraction operation and rotation by the arm. When,
A sensor disposed inside the vacuum transfer container and disposed between the arm and an opening of a passage communicating between the interior and the connected vacuum container and detecting the position of the wafer placed on the arm; ,
A controller that adjusts the transfer operation of the robot based on information on the position of the wafer obtained from the output of the sensor;
The acceleration of the wafer placed on the arm generated during the transfer operation by the robot is the maximum at the start of the extension of the arm or at the end of the contraction, and the controller detects the acceleration. A vacuum processing apparatus that reduces the acceleration at the start of extension or end of contraction of the arm of the robot when it is determined that the deviation of the position of the wafer exceeds a predetermined size. The vacuum processing apparatus according to claim 1,
The sensor is located between the outer peripheral edge of the wafer placed on the arm in a contracted state and the opening, and detects the position of the outer peripheral edge of the wafer,
2. The vacuum processing apparatus according to claim 1, wherein the acceleration is maximized before an outer peripheral edge of the rear wafer is detected by the sensor in the direction of extension or contraction of the transfer. The vacuum processing apparatus according to claim 1 or 2,
The controller adjusts the operation of the robot so that the acceleration of the wafer at the start of the lowered extension of the arm or the end of the contraction is greater than the acceleration generated during other operations of the transfer; A vacuum processing apparatus. A vacuum processing apparatus according to any one of claims 1 to 3,
The vacuum processing apparatus, wherein the wafer is held with a gap larger than a predetermined size of the gap between the wafer and the arm on the outer peripheral side of the outer peripheral edge.

Images