Synchronizing pin lifting device

Abstract

To provide a pneumatic pin lifting system.SOLUTION: In the system 1, the pin lifting device 10 includes a first pneumatic actuator 11 having a pneumatic cylinder 12 and a moving member 13 movably arranged inside thereof, a first control valve 21 connected to the first pneumatic actuator and a first fluid supply and controlling fluid flow of the first pneumatic actuator to provide movement of the first moving member, a first fluid sensor 22 arranged to measure pressurization and fluid flow from the first pneumatic actuator, and a control unit 30 controlling the first control valve and receiving a measurement signal of the first fluid sensor. The control unit provides reference movement information for moving the moving member from the start position to the end position, derives a first movement deviation, and adjusts the first control signal based on the first movement deviation in order to adjust the movement of the first moving member.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pin lift system and controller for providing improved drive performance of pin lift devices for operation in vacuum applications. [Background technology]

[0002] Background of the Invention Vacuum applications are typically carried out in vacuum chamber systems, for example in the area of ​​IC, semiconductor or substrate manufacturing, which must be carried out in as protective an atmosphere as possible without the presence of contaminating particles.

[0003] A vacuum chamber system includes at least one vacuum chamber that is specifically configured to receive semiconductor devices or substrates to be processed or manufactured, and that has at least one vacuum chamber opening through which the semiconductor devices or other substrates can be transferred into and out of the vacuum chamber. For example, in a semiconductor wafer or liquid crystal substrate manufacturing plant, sensitive semiconductor or liquid crystal devices pass through several process vacuum chambers in sequence, and components placed in the process vacuum chambers are processed by respective processing equipment.

[0004] The processing chamber often has a cross section adapted to accommodate the substrate and the robot, and at least one transfer valve that allows the substrate to be introduced into the vacuum chamber and, if necessary, removed after the intended processing. Alternatively, a second transfer valve may be provided through which the processed substrate is removed from the chamber.

[0005] Additionally, the processing system may include one or more peripheral units used to specifically control or regulate the flow of fluids into and / or out of the vacuum chamber, which may be provided by regulating valves located between the vacuum chamber and a vacuum pump or another vacuum chamber, or by gas inlet valves, e.g., mass flow controllers, located upstream to provide specific types and amounts of fluids into the vacuum chamber.

[0006] The substrate to be processed, e.g., a wafer, may be guided, for example, by a suitably designed and controlled robot arm, which may be guided through an opening in the processing chamber provided by a transfer valve. The processing chamber is then loaded by holding the substrate with the robot arm, introducing the substrate into the processing chamber, and depositing the substrate in the chamber in a specified manner. The processing chamber is then emptied accordingly.

[0007] For substrate handling and accurate positioning within the chamber, a relatively high degree of precision and mobility of the substrate must be ensured. For this purpose, a pin lifting system (pin lifter) is used, which provides multiple support points for the substrate and thus load distribution (due to the substrate's own weight) across the substrate. The pins can be lowered after depositing the substrate, after which they are separated from the substrate, i.e., there is no contact between the pins and the substrate. This allows the substrate to be lifted and deposited onto a support structure such as a chuck. After removing the robot arm and closing the chamber (and introducing or evacuating processing fluids), processing steps can be performed.

[0008] After processing the substrate, it must be lifted again. Here, a small force acting on the substrate is particularly important, for example, because the substrate may adhere to the carrier. If the substrate is pushed out of the carrier too quickly, the adhesive forces cannot be overcome or eliminated, at least at certain contact points, and the substrate may break. Furthermore, even if contact is established between the support pins and the substrate, any impact with the substrate may result in undesirable stress (or breakage).

[0009] At the same time, the most gentle and careful treatment of the substrates should be possible, as well as the shortest possible processing time. This means that the substrates should be brought into the specified conditions in the chamber, i.e., the loading and unloading positions and the processing position, as quickly as possible. Therefore, pin lifters with pneumatic actuators are preferred.

[0010] To avoid unwanted shocks during semiconductor wafer processing, for example, U.S. Patent No. 6,481,723 recommends the use of special stop devices instead of hard motion stops in pin lifters, where any hard stops should be replaced by a combination of a more flexible stop and hard stop, where contact with a soft stop is first made to limit movement, and then the hard stop contacts the soft stop and is damped accordingly.

[0011] US Patent No. 6,646,857 proposes adjusting the lifting action according to the recorded generated force: the lifting pins can be moved as a function of the force signal received so that the lifting force on the lifting pins is applied to the wafer in a constantly controlled manner.

[0012] Furthermore, when considering substrate handling, it is even more important to provide uniform movement of the lift pins so that all pins make as similar a contact with the substrate as possible. Furthermore, the pins should be moved with the same speed and acceleration. Both of these requirements provide a favorable distribution of contact forces across the substrate, as well as horizontal alignment and transport of the substrate.

[0013] However, pneumatic pin lifting devices used in wafer lifting applications are built to similar specific tolerances (technical logical deviations). The tolerance differences can occur in various aspects such as spring stiffness, different friction coefficients, mechanical dimensions / parameters, or at the proportional valve level that provides a specific lifter pressurization.

[0014] During typical open-loop operation of a pin lifter, no controller is present to account for discrepancies. A simple pressure / voltage signal is preferably applied to the lifter system, assuming that all pin lifters behave identically and ideally. However, as noted above, technical discrepancies exist between each pin lifting device, which can result in non-identical responses between pin lifting devices during simultaneous operation when using the same input voltage or pressure. This can cause position and velocity deviations during the motion profile, risking pin lifter misalignment and subsequent wafer misalignment or damage. Summary of the Invention [Problem to be solved by the invention]

[0015] Object of the invention It is therefore an object of the present invention to provide an improved pneumatic pin lift system that reduces or avoids the above-mentioned drawbacks.

[0016] In particular, it is an object of the present invention to provide an improved pneumatic actuation system that allows for reliable movement of all deployed pin lifting devices. [Means for solving the problem]

[0017] These objects are solved by implementing the characterizing features of the independent claims. Features which further develop the invention in an alternative or advantageous way can be found in the dependent claims.

[0018] Summary of the Invention The approach according to the invention proposes to remedy the above problem by an open-loop adjustment or training phase, in which, for example, the time of movement of a moving member or mount of a pin lifting device between different known positions (e.g., between a start position and an end position, e.g., a full-stroke hard stop or wafer contact position) is measured for a pin lifting device or for multiple pin lifting devices given the same input signal (e.g., input pressure or control voltage).

[0019] The timing difference between the motion profile of the pin lifting device and a reference profile can then be determined. The reference profile can be provided based on any motion profile of the pin lifting device or can be provided by a (virtual) predetermined reference profile.

[0020] The control inputs (control signals) can then be adjusted and scaled accordingly for each pin lifting device, i.e., each associated control valve, to match the reference motion profile, particularly in timing and / or temporal position.

[0021] This reduces the undesirable effects of technological variations in the pin lifter and improves the positioning of the synchronous operation.

[0022] The present invention relates to a pin lift system including at least a first pin lift device configured to move and position a substrate to be processed within a process atmosphere that can be provided by a vacuum processing chamber. The pin lift device can include lift pins that contact the substrate (e.g., a wafer) and lift and lower the substrate.

[0023] The first pin lifting device includes a first pneumatic actuator having a first pneumatic cylinder and a first moving member movably disposed inside the first pneumatic cylinder, the first moving member being configured to be connected to the lift pins and movable along a first movement axis. In particular, the first moving member is movable from a lowered normal position to an elevated position and back again. The lift pins, which can be respectively connected to the moving members, are movable accordingly when connected.

[0024] The pin lifting system includes a first control valve connected to the first pneumatic actuator and the first fluid supply and configured to control pressurization of the first pneumatic actuator and / or fluid flow to or from the first pneumatic actuator to provide movement (in the extension direction) of the first moving member. In particular, the control valve can be configured to control and provide a predetermined pressure or pressure change in the actuator, in particular in the pneumatic cylinder or at least one chamber of the pneumatic cylinder of the actuator. Alternatively or additionally, the control valve can be configured to control and provide a predetermined fluid flow or rate or change in rate in the pneumatic actuator.

[0025] The system further includes a first fluid sensor positioned and configured to measure pressurization of the first pneumatic actuator and / or fluid flow from or to the first pneumatic actuator. Thus, the fluid sensor may be embodied to measure pressure. Alternatively or additionally, the fluid sensor may be configured to measure flow or rate.

[0026] A control unit is provided and configured to control the first control valve by applying a first control signal and to receive the measurement signal of the first fluid sensor.

[0027] The control unit is configured to adjust the movement of the first moving member by providing reference movement information, the reference movement information representing at least a reference duration for moving the moving member of a (e.g., typical or general) pin lifting device from a start position to an end position.

[0028] The reference movement information may not be related to a particular or individual pin lifting device, but may be more general information about the pin lifter being moved or the type of such pin lifter. The reference movement information may relate to a particular processing cycle, e.g., how to control the pin lifting device according to a particular process.

[0029] A first control signal is applied to the first control valve to move a first moving member of the first pin lifting device from a first start position to a first end position, and the applied control signal can be a standard control signal that has not yet been adjusted to a particular lifting device.

[0030] First movement information relating to movement of the first moving member from a first start position to a first end position is determined.

[0031] The first movement information is compared with the reference movement information, and (based thereon) a first movement deviation is derived.

[0032] The first control signal is adjusted based on the first moving deviation.

[0033] In particular, as a result, an adjusted control signal can be determined that can be applied to the first pin lifting device to provide a movement of the first moving member that is adjusted to the reference movement.

[0034] In one embodiment, the first movement information comprises: a first movement time of the first moving member, the first movement time corresponding to the duration of time for the first moving member to move from the first start position to the first end position by application of the first control signal; a first pressure-time profile providing information about the change in pressure in the chamber of the first pneumatic actuator, in particular the first pneumatic cylinder, during the time it takes to move at least the first moving member from the first start position to the first end position; a first flow-time profile providing information regarding changes in fluid flow into and out of the first pneumatic actuator during a time period for moving at least the first moving member from a first start position to a first end position; a first position-time profile providing information regarding a change in position of the first moving member along the first axis of movement when moving the at least first moving member from a first start position to a first end position; It may include at least one of:

[0035] The reference movement information is a reference travel time for the moving member of the pin lifting device, the reference travel time corresponding to the duration of moving the moving member from the start position to the end position by applying a control signal; a reference pressure-time profile that provides information about the change in pressure within the pneumatic actuator at least over the time it takes to move the moving member from a start position to an end position; a reference flow-time profile that provides information about changes in fluid flow into and out of the pneumatic actuator over a time period that moves at least the first moving member from a start position to an end position; a reference position-time profile providing information about the change in position along the axis of movement of the moving member at least as the moving member moves from a start position to an end position; It may include at least one of:

[0036] In one embodiment, the first moving deviation is: Time deviation, deviations with respect to the pressure-time profile, deviations with respect to the flow-time profile, and Deviations with respect to the position-time profile It may include at least one of:

[0037] Such deviations can provide a suitable basis for how to adjust the control signal. For example, if there is little difference in the pressure-time profiles, e.g., the reference profile and the measured profile, a small change in the control signal may be sufficient.

[0038] In one embodiment, the first end position is: a first hard stop of the first pin lifting device; The position where the substrate comes into contact with the lift pins, or First pin lifting device full stroke may be provided by at least one of

[0039] Such a first hard stop may be arranged inside the pneumatic cylinder to limit the range of movement of the moving member in at least one direction, in particular the extension direction.

[0040] According to one embodiment, the control unit may be configured to detect the reaching of the first end position by the first moving member by measuring pressurization of and / or fluid flow to the first pneumatic actuator by a first fluid sensor and monitoring a change in pressure in the first pneumatic actuator and / or fluid flow to the first pneumatic actuator and / or a change in volume of a first chamber of the actuator.

[0041] In particular, the first control signal is further considered or processed to determine the reaching of the first end position by the first moving member.

[0042] In one embodiment, the first pin lifting device may include a position sensor configured and arranged to obtain position data regarding the position of the first moving member and / or the mount of the pin lifting device along the first axis of movement, in particular to obtain position data regarding the first end position. The control unit may be configured to receive the position data and detect when the first moving member has reached the first end position.

[0043] In one embodiment, the first control valve can provide a predetermined fluid flow into or a predetermined fluid pressure within the first pneumatic actuator in response to an applied control signal, the control signal providing a control voltage or a control current. Further, adjusting the first control signal can include adjusting the control voltage or the control current to provide movement of the first moving member according to the reference movement information.

[0044] In particular, if the duration of moving the first moving member from the first start position to the first end position is shorter than the reference duration, adjusting the first control signal may include reducing the flow of fluid to the first pneumatic actuator by applying the first control signal, in particular reducing the control voltage and / or the control current.

[0045] In particular, if the duration of moving the first moving member from the first start position to the first end position is longer than the reference duration, adjusting the first control signal may include increasing the flow of fluid to the first pneumatic actuator by applying the first control signal, in particular increasing the control voltage and / or current.

[0046] In one embodiment, the pin lifting system can include a second pin lifting device including a second pneumatic actuator having a second pneumatic cylinder and a second moving member movably disposed inside the second pneumatic cylinder, the second moving member configured to be connected with the lift pins and movable along a second movement axis, in particular from a lowered normal position to a raised lifting position and back again.

[0047] The pin lifting system may further include a second control valve connected to the second pneumatic actuator and the second fluid supply and configured to control pressurization of the second pneumatic actuator and / or flow of fluid from or to the second pneumatic actuator to move the second moving member in the extension direction.

[0048] The second fluid sensor may be positioned and configured to measure pressurization of the second pneumatic actuator and / or fluid flow from or to the second pneumatic actuator.

[0049] The control unit can be configured to: move the second moving member from a second start position to a second end position by applying a second control signal to the second control valve; determine second movement information regarding the movement of the second moving member from the second start position to the second end position; compare the second movement information with reference movement information to derive a second movement deviation; and adjust the second control signal based on the second movement deviation, respectively.

[0050] In an alternative embodiment, the second control valve may be embodied by the first control valve, for example, the first and second pin lifting devices are controlled by one common valve.

[0051] According to one embodiment, the control unit may be configured to provide the reference movement information based on the first movement information and / or the second movement information, in particular based on processing or averaging the first and second movement information. In particular, the first movement information may be used as the reference movement information.

[0052] This allows for adjustment of one pin lifting device based on the characteristics of another such device and / or based on (separate) criteria.

[0053] In one embodiment, the control unit may be configured to synchronize the movements of the first and second moving members by comparing the first movement information and the second movement information, deriving a synchronous movement deviation, and adjusting the first and / or second control signals based on the synchronous movement deviation to provide for the arrival of the first end position and the second end position having identical movement durations for the first and second moving members.

[0054] In one embodiment, the control unit Equally pressurizing the first pneumatic actuator and the second pneumatic actuator and / or providing equal fluid flow to the first pneumatic actuator and the second pneumatic actuator, thereby moving the first moving member and the second moving member in the extension direction; and / or applying identical control signals to the first and second control valves to provide movement of the first and second moving members to the first and second end positions; and / or providing a regulated first control signal and / or a regulated second control signal to open-loop control the first control valve and / or the second control valve; It can be configured as follows.

[0055] According to one embodiment, the first fluid supply and the second fluid supply provide a predetermined fluid pressure, or the second fluid supply is provided by the first fluid supply. For example, the control valves of the system can be supplied by one common fluid supply.

[0056] In the case of at least two fluid supplies, additional fluid (e.g., flow) sensors can be positioned between each fluid supply and the supplied control valve to measure the inlet flow rate and / or pressure to the control valve, thereby providing (and knowing) a specific flow rate through the control valve.

[0057] In one embodiment, the first pneumatic actuator includes a first chamber and a second chamber within the pneumatic cylinder, the first chamber being defined by a first moving member separating the interior volume of the pneumatic cylinder. A stem can be connected to the moving member, extending outside the pneumatic cylinder and connected to a first mount. The first mount can be configured to hold and provide a lift pin. A first fluid passage can provide passage of fluid into and out of the first chamber.

[0058] The first control valve can be connected to the first fluid passageway and can be configured to provide control of fluid flow to the first chamber, and the first fluid sensor can be positioned and configured to measure pressure in the first chamber and / or fluid flow from or to the first chamber.

[0059] In particular, the first pneumatic actuator can include a second fluid passageway providing passage of fluid into and out of the second chamber, and a third control valve connected to the second fluid passageway and configured to provide control of the flow of fluid into the second chamber.

[0060] In particular, the first pneumatic actuator may include a first restoring element connected to the moving member and applying a first restoring force to the moving member acting in a direction opposite to the extension direction.

[0061] The present invention also relates to a control unit for a pin lift system, the pin lift system including at least a first pin lift device configured to move and position a substrate to be processed within a process atmosphere that can be provided by a vacuum processing chamber.

[0062] At least the first pin lifting device includes a first pneumatic actuator having a first pneumatic cylinder and a first moving member movably arranged inside the first pneumatic cylinder, the first moving member being configured to be connected to the lift pins and being movable along a first movement axis, in particular from a lowered normal position to a raised lifting position and back again.

[0063] The pin lifting system includes a first control valve connected to the first pneumatic actuator and the first fluid supply and configured to control pressurization of the first pneumatic actuator and / or fluid flow from or to the first pneumatic actuator to move the first moving member in the extension direction. The pin lifting system also includes a first fluid sensor positioned and configured to measure pressurization of the first pneumatic actuator and / or fluid flow from or to the first pneumatic actuator.

[0064] The control unit is configured to provide reference movement information representing at least a reference period for moving a moving member of the pin lifting device from a start position to an end position, move the first moving member from the first start position to the first end position by applying a first control signal to a first control valve, determine first movement information regarding the movement of the first moving member from the first start position to the first end position, compare the first movement information with the reference movement information to derive a first movement deviation, and adjust the first control signal based on the first movement deviation.

[0065] According to an embodiment, the control unit may be configured in accordance with the control units described herein.

[0066] The system according to the invention and the method according to the invention will now be described in detail, by way of example only, with reference to particular exemplary embodiments which are shown diagrammatically in the drawings, and further advantages of the invention will also be discussed. [Brief explanation of the drawings]

[0067] [Figure 1] FIG. 1 illustrates one embodiment of a pin lifting system according to the present invention. [Figure 2] FIG. 10 illustrates another embodiment of a pin lifting system according to the present invention. [Figure 3a] 10A and 10B illustrate the control behavior of two pin lifting devices before and after adjusting the control signals according to the present invention. [Figure 3b]10A and 10B illustrate the control behavior of two pin lifting devices before and after adjusting the control signals according to the present invention. [Figure 4] FIG. 10 illustrates another embodiment of a pin lifting system according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0068] Detailed Description of the Drawings FIG. 1 shows a schematic representation of an embodiment of a pin lifting system 1 according to the present invention.

[0069] The pin lifting system 1 includes a pin lifting device 10 having a pneumatic actuator 11. The pneumatic actuator 11 includes a cylinder 12 separated into two chambers 14, 15 by a moving member 13. The moving member 13 is preferably a piston. A stem 16 is connected to the moving member 13 and extends outside the internal volume of the cylinder 12. The stem 16 is configured to provide actuation for a connected first mount 17 to be moved. The mount 17 has a lift pin 20 attached to it. Thus, a load is applied to the moving member 13 by the stem 16, i.e., by its weight, and / or by additional elements interacting with the stem 16, such as the lift pin 20 or the lifted substrate.

[0070] It should be understood that at least the mount 17 is an optional element. Alternatively, the connection between the moving member 13 and the lift pins 20 may be provided by a direct connection, in particular, the moving member 13 and the lift pins 20 are constructed as a single part.

[0071] The pneumatic actuator 11 further includes a first fluid passageway 19. The first fluid passageway 19 allows fluid to flow into and out of the first chamber 15.

[0072] Furthermore, the pneumatic actuator 11 includes a restoring element 18, in particular a spring. The restoring element 18 is connected to the moving member 13 and applies a restoring force to the moving member 13. In the illustrated embodiment, the restoring element 18 is arranged inside the second chamber 14.

[0073] The system 1 also includes a first control valve 21 connected to the first fluid passage 19 and to a fluid supply and configured to control the flow of fluid into the first chamber 15. The fluid supply may be provided by a source of high pressure fluid, for example a reservoir of compressed air. The first control valve may be a proportional control valve capable of providing a defined flow of fluid as a function of a respective applied control signal.

[0074] Control valve 21 provides controlled variation of flow and / or pressure to chamber 15 .

[0075] The first fluid sensor 22 is positioned and configured to measure the pressure in the first chamber 15, i.e., on one side of the pneumatic cylinder. The first fluid sensor is embodied as a pressure sensor 22 and provides pressure feedback from the first chamber 15, i.e., the pressure affecting the moving member 13.

[0076] In an alternative embodiment, the first fluid sensor 22 may be a flow meter that measures the flow of fluid out of the control valve 21 and into the chamber 15 .

[0077] In an alternative embodiment, the system may include an additional flow meter to further measure fluid flow from the fluid supply to the control valve, thereby allowing the flow into and out of the control valve 21 to be determined.

[0078] In an alternative embodiment, the first fluid sensor may be a flow sensor.

[0079] As shown, a pressure sensor can be located in the supply line of each chamber 15. A pressure sensor 22 can be located with each control valve 21 (as shown) or can be located separately from the valve 21 (not shown).

[0080] The pin lifting system 1 includes a control unit 30. The control unit 30 is configured to control the movement of the moving member 13 by applying a particular pressure in the chamber 15. The pressure in the chamber 15 can be varied by controlling the control valve 21 to increase or decrease the pressure in the chamber 15.

[0081] The control unit 30 is connected to the pressure sensor 22 to receive pressure information about the chamber 15 .

[0082] In one embodiment, the control unit 30 may be integral with the pressure sensor 22 .

[0083] The control unit 30 is configured to derive and generate respective control signals for the first control valve 21. The control signals can set and modify the pressure inside the first chamber 15 and thereby the force counteracting the restoring force of the restoring element 18.

[0084] In accordance with the present invention, the movement of the pin lifter 10, i.e., the moving member 13 and mount 17, due to the application of a control signal can be adjusted by running a prescribed learning or adjustment cycle. This can be particularly advantageous because pin lifters are typically driven in an open-loop manner, i.e., there is no feedback information available to control or adjust the movement of the moving member 13 when varying the pressure in the first chamber 15.

[0085] The movement of the first moving member 13 is adjusted by respectively adjusting the control signal to provide a predetermined pressurization of the first chamber 15. To this end, reference movement information is provided. The reference movement information represents a reference duration for moving at least the moving member of the pin lifting device from a start position to an end position. Such reference movement information may be generated by an operator of the system 1 or may be derived, for example, based on a previous execution of such an adjustment cycle by a further pin lifting device.

[0086] The reference movement information can include a reference movement time of the moving member of the pin lifting device, the reference movement time corresponding to the duration of moving the moving member from the start position to the end position by applying the control signal. Further, the reference movement information can include a reference position-time profile that provides information about a change in position along the movement axis of the moving member during at least the time it takes to move the moving member from the start position to the end position.

[0087] In particular, the reference movement information is not assigned to or connected to any control or structural design of the pin lifter 10 whose movement is to be coordinated. However, the reference movement information should provide a target or nominal state of motion to which the pin lifter 10 should be driven.

[0088] To adjust the movement of the first moving member 13 or the first mount 17, the moving member is preferably provided in a first starting position. The first starting position can correspond to the "0" position, i.e., a position in which the mount 17 and the moving member 13 are provided, for example, retracted to the lowest possible position. Alternatively, the moving member 13 is provided in a respectively determined alternative position.

[0089] The first start position of the first moving member 13 correlates with the start position referred to by the reference movement information.

[0090] The control unit 30 is configured to provide a movement of the first moving member 13 from a first start position to a first end position by applying a first control signal to the first control valve. The first end position may correspond to a full stroke of the moving member, i.e., a position provided when the moving member 13 reaches a hard stop 25 provided inside the cylinder 12.

[0091] Alternatively, the first end position may be provided by the position where the substrate is brought into contact with the lift pins 20, or any other position that can be determined, respectively.

[0092] The control unit 30 is further configured to determine first movement information regarding the movement of the first moving member 13 from the first start position to the first end position. The first movement information may include a first movement time of the first moving member 13, the first movement time corresponding to the duration of moving the first moving member 13 from the first start position to the first end position by applying the first control signal. Furthermore, the first movement information may include a first position-time profile providing information regarding a change in position of the first moving member 13 along the first movement axis at least during the time of moving the first moving member 13 from the first start position to the first end position.

[0093] The control unit further provides a step of comparing the first movement information with reference movement information and deriving a first movement deviation. From knowing the control signal applied to drive the moving member 13, such input can be adjusted and scaled accordingly to the first pin lifting device 10 to match the reference movement information (e.g., reference motion profile) in timing and time position.

[0094] The first movement deviation may include a time deviation for a duration to reach the end position or a deviation for a position-time profile, and the first control signal is adjusted accordingly based on the first movement deviation.

[0095] To adjust the control signal, a previously known response of the moving member 13 as a function of the applied control signal, in particular the applied control voltage, is taken into account or processed. The outlet flow of the control valve 21 can be changed by changing the applied control voltage. In other words, the change in the motion behavior of the moving member 13 due to a particular change in the control signal can at least be estimated or is known.

[0096] In one embodiment of the present invention, several adjustment cycles are performed to iteratively adjust the motion characteristics of the pin lifting device 10 to approach the reference characteristics.

[0097] The reaching of the moving member 13 to the first end position can be detected by the control unit 30 by measuring the pressurization of the first pneumatic actuator by the first pressure sensor 22 and monitoring the change in pressure in the first pneumatic actuator. For example, when the hard stop 25 is brought into contact with the moving member 13, the path of the time-pressure curve can deviate from a preferably homogeneous development, providing a pressure peak that is detected.

[0098] This means that the moment when the mount and / or moving member reaches the end position can be detected by the pressure sensor 22 and the control unit 30 .

[0099] In one embodiment, the pin lifting system 1 may include a temperature sensor to measure the ambient temperature and / or the temperature of the fluid used to pressurize the first actuator 11. Because the temperature or changes in temperature of the fluid can have a significant effect on the resulting pressure in the chamber 15 when delivering a particular amount of fluid, information about the actual temperature may be further processed to adjust the control signal.

[0100] In one embodiment, information may be available regarding the pressure of the supply fluid supplied to the control valve 21. Because the supply pressure may directly affect the resulting chamber pressure, this information may also be taken into account to adjust the control signal.

[0101] 2 shows an embodiment of a pin lifting system 1 according to the present invention. In contrast to the embodiment of FIG. 1, here a second pin lifting device 40, a second control valve 23, and a second fluid sensor 24 are arranged. Both pin lifting devices 10 and 40 are provided for handling substrates 5, e.g., semiconductor wafers, in a vacuum atmosphere. Thus, lift pins 20 and 20′ can be provided inside a vacuum chamber, while their respective pneumatic actuators 11 and 41 can be located outside the vacuum chamber.

[0102] As mentioned above, substrates must be handled with high precision, i.e., they must be raised and lowered while remaining horizontally aligned and without misalignment. To achieve this, the movements of the pin lifting devices 10 and 40, i.e., their lift pins 20 and 20', must be synchronized. Due to structural variations in the pin lifting devices 10 and 40 (due to natural component tolerances or different spring constants), such movements of the lift pins 20 and 20' when the same pressure is applied to each pneumatic actuator 11 and 41 are also typically not identical.

[0103] Thus, according to the invention, adjustment of the movement behavior of at least one of the pin lifting devices 10 and 40 can be carried out.

[0104] As can be seen, the second pin lifting device 40 includes a second pneumatic actuator 41 including a second cylinder 42, a second moving member 43, third and fourth chambers 44 and 45 inside the cylinder 42, respectively, a second stem 46, and a second restoring element 48. Furthermore, the second pin lifting device 40 includes a second mount 47, a second hard stop 25′, and a second fluid passage 49. The second moving member 43 and / or the second mount 48 are movable along a second movement axis M2.

[0105] The second control valve 23 and the second fluid sensor 24 are connected to the control unit 30 .

[0106] The control unit 30 is configured to provide for the coordination of the motion profile of at least one of the two pin lifting devices 10 and 40 in order to provide identical or synchronized motion profiles for both lifters 10,40.

[0107] To that end, the adjustment cycle as described above is performed by both pin lifting devices 10 and 40.

[0108] The movement of the first moving member 13 and the second moving member 43 from their respective (first and second) start positions to their respective (first and second) end positions by applying respective (first and second) control signals to the respective (first and second) control valves 21, 23 is provided (controlled) by the control unit 30.

[0109] First and second movement information relating to the movement of the first and second moving members 13, 43 from the start position to the end position, respectively, is derived.

[0110] When synchronizing the motion profiles of the two pin lifting devices 10, 40, the first and second motion information are compared, and a motion deviation is derived based on the comparison. Here, one of the determined motion profiles (first and second motion information) can be considered as a reference motion profile (reference motion information).

[0111] Such movement deviation can further be used to determine the difference in duration when the moving members 13, 43 reach their end positions. Based on this, the control signal of one of the control valves 21 or 23 can be adjusted to accelerate or decelerate the movement of the respective moving member when the adjusted control signal is applied.

[0112] By knowing the dimensions of the chambers 15, 45, in particular the effective surface of the moving members 13, 43, and / or the properties of the restoring elements 18, 48, in particular the spring constant, it is possible to predict or estimate the change in the motion profile of the respective moving members 13, 43 depending on how the respective actuators 11, 41 are pressurized, and therefore to provide adjustments to the control signals, respectively.

[0113] If the motion profiles of the two pin lifting devices 10 and 40 are to be synchronized with a (further) reference motion profile (reference motion information), both the first and second motion information are compared with the reference motion information, and respective first and second motion deviations are derived. The control signals of both the first and second control valves 21, 23 are adjusted to match the reference motion profile.

[0114] 3a and 3b show the motion behavior of two pin lifting devices of a pin lifting system according to the invention before and after adjusting the control signal used to control the control valve or adjusting the generation of pressurization of the actuator.

[0115] 3a shows a first motion profile 51 (position x over time t) of a first pin lifting device when a first moving member is moved from a first start position to a first end position by applying a first control signal 61 (signal S over time t), which first control signal 61 corresponds to a standard or calibrated control signal 60. Additionally, a second motion profile 52 of a second pin lifting device is shown when a second moving member is moved from a second start position to a second end position by applying a second control signal 62, which second control signal 62 also corresponds to the standard or calibrated control signal 60.

[0116] Additionally, a reference motion profile 50 (reference movement information) that is desired to be achieved by the first and second pin lifting devices is shown. A standard or calibrated control signal 60 is assigned to the reference motion profile 50.

[0117] Based on the first motion profile 51 and the second motion profile 52, respective movement times t1 and t2 representing the duration of each movement from the start position to the end position are derived. ref Furthermore, the travel times t1 and t2 are calculated as the reference travel time t ref By comparing the deviations of the travel time with the deviations of the travel time, the deviations of the travel time can be determined.

[0118] Control signals 61 and 62 can then be adjusted to provide a tailored motion profile.

[0119] 3b shows the result of adjusting the control signals 61 and 62. It is determined that the first pin lifting device is moving too fast, i.e., the movement time t1 is shorter than the reference movement time t ref Since the first control valve 61 is shorter than the first control valve 61, the control signal 61 is adjusted lower, i.e., the control voltage or current is reduced, resulting in less fluid flow through the first control valve 61. This reduces the pressure rise in the chamber of the first pin lifting device 61, and therefore slows the movement of the first moving member 61 when the first control signal 61 is applied.

[0120] Regarding the motion profile 52 of the second pin lifting device, it was found to be moving too slowly, i.e., the travel time t2 is shorter than the reference travel time t ref Therefore, the control signal 62 is adjusted to be stronger, i.e., the control voltage or control current is increased, resulting in a greater flow of fluid through the second control valve. This results in an increase in pressure in the chamber of the second pin lifting device, and therefore a faster movement of the second moving member when the second control signal 62 is applied.

[0121] Finally, the motion profiles 51 and 52 of the first and second pin lifting devices correspond to the reference profile 50 .

[0122] It should be understood that the techniques described herein are not limited to application to two pin lifting devices, but can be applied to multiple pin lifting devices resulting in synchronized movement of the multiple pin lifting devices.

[0123] Figure 4 shows an embodiment of a pin lifting system 1 according to the invention. In contrast to the embodiment of Figure 1, here the first pin lifting device does not comprise a restoring element but comprises an additional fluid passage 19' for the second chamber 14.

[0124] The movement of the moving member 13 can be controlled by applying and modifying respective control signals by means of two control valves 21 and 27. This allows the pressure and pressure difference between the two chambers 14, 15 to be set and modified, respectively.

[0125] Referring to the adjustment of the motion profile of the pin lifting device, an adjustment cycle can be performed as described above. Based on the determined motion deviation, the control signal of one or both of the control valves 21, 27 can be adjusted to adjust the pressure differential created when the signal is applied, thereby changing the motion profile.

[0126] It is understood that the depicted diagrams only diagrammatically illustrate possible exemplary embodiments. The various techniques according to the invention can also be combined with each other and with prior art methods and devices for controlling pneumatic actuators.

Claims

1. A pin lifting system (1), comprising: at least a first pin lifting device (10) configured to move and position a substrate (5) to be processed within a processing atmosphere region that can be provided by a vacuum processing chamber, the first pin lifting device (10) including a first pneumatic actuator (11) having a first pneumatic cylinder (12) and a first moving member (13) movably arranged inside the first pneumatic cylinder (12), the first moving member (13) configured to be connected to lift pins (20) and movable along a first moving axis (M1); a first control valve (21) connected to the first pneumatic actuator (11) and to a first fluid supply and configured to control at least one of pressurization of the first pneumatic actuator (11) or fluid flow into or out of the first pneumatic actuator (11) to provide movement of the first moving member (13); a first fluid sensor (22) arranged and configured to measure at least one of the pressurization of the first pneumatic actuator (11) or the flow of fluid into or out of the first pneumatic actuator (11); a control unit (30) configured to control the first control valve (21) by applying a first control signal and to receive the measurement signal of the first fluid sensor (22); Including, The control unit (30) controls the movement of the first moving member (13) by providing reference movement information representing a reference duration for moving at least a moving member of the pin lifting device from a start position to an end position; - applying the first control signal to the first control valve (21) to move the first moving member (13) from a first start position to a first end position; - determining first movement information relating to the movement of the first moving member (13) from the first start position to the first end position; comparing the first movement information with the reference movement information and deriving a first movement deviation; adjusting the first control signal based on the first motion deviation; A pin lifting system (1) characterized in that it is configured to be adjusted by.

2. The first movement information is a first movement time of the first moving member (13), the first movement time corresponding to the duration of time during which the first moving member (13) is moved from the first start position to the first end position by application of the first control signal; a first pressure-time profile providing information about the change in pressure of the first pneumatic actuator (11) over the time it takes to move at least the first moving member (13) from the first start position to the first end position; a first flow-time profile providing information about the change in fluid flow into and out of said first pneumatic actuator (11) during the time it takes to move at least said first moving member (13) from said first start position to said first end position; a first position-time profile providing information about the change in position of the first moving member (13) along the first axis of movement (M1) when moving at least the first moving member (13) from the first start position to the first end position; and The reference movement information is a reference travel time for a moving member of a pin lifting device, the reference travel time corresponding to the duration of time that the application of a control signal causes said moving member to move from said start position to said end position; a reference pressure-time profile providing information about the change in pressure within the pneumatic actuator at least over the time it takes to move the moving member from the start position to the end position; a reference flow-time profile that provides information about changes in fluid flow into and out of the pneumatic actuator during the time it takes to move at least the first moving member from the start position to the end position; a reference position-time profile providing information about the change in position along the axis of movement of the moving member at least as the moving member moves from the start position to the end position; at least one of: A pin lifting system (1) according to claim 1.

3. The first movement deviation is - time deviation, deviations with respect to the pressure-time profile, deviations with respect to the flow-time profile, and deviations with respect to the position-time profile, 3. A pin lifting system (1) according to claim 1 or 2, comprising at least one of:

4. The first end position is: a first hard stop (25) of said first pin lifting device (10); a position where the substrate (5) is brought into contact with the lift pins (20), or - the full stroke of the first pin lifting device (10); A pin lifting system (1) according to any one of claims 1 to 3, provided by

5. The control unit controls the first moving member (13) to reach the first end position by: - measuring the pressurization of the first pneumatic actuator (11) by the first fluid sensor (22); - monitoring the change in pressure in the first pneumatic actuator (11); 5. The pin lifting system (1) according to any one of claims 1 to 4, configured for detection by:

6. the first pin lifting device (10) includes a position sensor that acquires position data relating to the position of the first moving member along the first axis of movement; the control unit is configured to receive the position data and to detect when the first moving member has reached the first end position; A pin lifting system (1) according to any one of claims 1 to 5.

7. the first control valve (21) provides a defined fluid flow into or a defined fluid pressure in the first pneumatic actuator (11) as a function of the applied control signal, the control signal providing a control voltage or control current; adjusting the first control signal adjusts the control voltage or the control current to effect movement of the first moving member (13) according to the reference movement information; 7. A pin lifting system (1) according to any one of claims 1 to 6, comprising:

8. The pin lifting system (1) a second pin lifting device (40) including a second pneumatic actuator (41) having a second pneumatic cylinder (42) and a second moving member (43) movably arranged inside the second pneumatic cylinder (42), the second moving member (43) being configured to be connected to the lift pin (20′) and movable along a second movement axis (M2); a second control valve (23) connected to the second pneumatic actuator (41) and to a second fluid supply and configured to control at least one of pressurization of the second pneumatic actuator (41) or fluid flow into or out of the second pneumatic actuator (41) to provide movement of the second moving member (43); a second fluid sensor (24) arranged and configured to measure at least one of the pressurization of the second pneumatic actuator (41) or the flow of fluid into or out of the second pneumatic actuator (41); Including, The control unit (30) controls the movement of the second moving member (43) by - applying a second control signal to the second control valve (23) to move the second moving member (43) from a second start position to a second end position; - determining second movement information relating to the movement of the second moving member (43) from the second start position to the second end position; - comparing the second movement information with the reference movement information and deriving a second movement deviation; adjusting the second control signal based on the second motion deviation; The pin lifting system (1) according to any one of claims 1 to 7, configured for adjustment by

9. The pin lifting system (1) of claim 8, wherein the control unit (30) is configured to provide the reference movement information based on at least one of the first movement information or the second movement information.

10. The control unit (30) - comparing the first movement information with the second movement information; Deriving a synchronous movement deviation; adjusting at least one of the first control signal or the second control signal based on the synchronous movement deviation to provide for the first moving member and the second moving member to reach the first end position and the second end position with the same movement duration; 10. The pin lifting system (1) according to claim 8 or 9, configured to synchronize the movements of the first and second moving members by

11. The control unit (30) - equally pressurizing the first and second pneumatic actuators, thereby moving the first and second moving members in an extension direction; applying identical control signals to the first and second control valves (21) to provide movement of the first and second moving members to the first and second end positions; the regulated first control signal or the regulated second control signal for open-loop control of the first or second control valve; 11. The pin lifting system (1) according to any one of claims 8 to 10, configured to provide at least one of:

12. 12. The pin lifting system (1) according to any one of claims 8 to 11, wherein the first fluid supply and the second fluid supply provide a predetermined fluid pressure or the second fluid supply is provided by the first fluid supply.

13. said first pneumatic actuator (11) a first chamber (15) and a second chamber (14) within the pneumatic cylinder (12) defined by providing a separation of the interior volume of the pneumatic cylinder (12) by the first moving member (13); a stem (16) connected to the moving member (13), extending outside the pneumatic cylinder (12), and connected to a first mount (17); a first fluid passageway (19) providing passage of fluid into and out of said first chamber (15); the first control valve (21) is connected to the first fluid passage (19) and configured to provide control over at least one of pressurization of the first chamber (15) or fluid flow into or out of the first chamber (15); the first fluid sensor (22) is positioned and configured to measure at least one of the pressure in the first chamber (15) or the flow of the fluid into or out of the first chamber (15); A pin lifting system (1) according to any one of claims 1 to 12.

14. 1. A control unit for a pin lift system, said pin lift system comprising: at least a first pin lifting device (10) configured to move and position a substrate (5) to be processed within a processing atmosphere region that can be provided by a vacuum processing chamber, said at least first pin lifting device (10) including a first pneumatic actuator (11) having a first pneumatic cylinder (12) and a first moving member (13) movably arranged inside said first pneumatic cylinder (12), said first moving member (13) configured to be connected to lift pins (20) and movable along a first moving axis (M1); a first control valve (21) connected to the first pneumatic actuator and to a first fluid supply and configured to control at least one of pressurization of the first pneumatic actuator or a flow of fluid to or from the first pneumatic actuator to provide movement of the first moving member (); a first fluid sensor (22) positioned and configured to measure at least one of the pressurization of the first pneumatic actuator or the flow of fluid into or out of the first pneumatic actuator; Including, The control unit - providing reference movement information representing a reference duration for moving at least the moving member of the pin lifting device from the start position to the end position; - applying a first control signal to the first control valve (21) to move the first moving member (13) from a first start position to a first end position; - determining first movement information relating to the movement of the first moving member (13) from the first start position to the first end position; - comparing the first movement information with the reference movement information to derive a first movement deviation; adjusting the first control signal based on the first movement deviation; The control unit is configured to:

15. 15. A control unit according to claim 14, wherein the control unit is configured in accordance with a control unit according to any one of claims 1 to 13.

Images