Vacuum range adjustment device with pressure measurement function

Abstract

A vacuum regulating apparatus (10) for a movable active element in a process atmosphere region includes a coupling (18) and a drive unit having an electric motor (12) and cooperating with the coupling (18) to adjust the coupling (18) from a normal position to an active position and back. The apparatus includes a mechanical interface for connecting the vacuum regulating apparatus (10) to a process space providing the process atmosphere, a dynamic isolation device (15) for isolating the process atmosphere from an external atmosphere region (A), and a control processing unit at least electrically connected to the drive unit and designed to control the electric motor (12). The control processing unit has a pressure measurement function designed to derive motor status information based on magnitudes of motor operating parameters, derive a load differential by comparing the motor status information to known motor target states, and derive a differential pressure between the external atmosphere region (A) and the process atmosphere region (P) based on the load differential.

Description

[Technical field]

[0001] The present invention relates to a vacuum regulating device for moving and positioning an active element, which can be connected to a drive unit by a coupling, within a process atmosphere. [Background technology]

[0002] Such adjustment devices designed for vacuum applications are used, for example, to position substrates to be processed in a vacuum chamber. The substrates are usually introduced into the process space by a robot, where they must be placed at predefined installation points in the chamber and lifted off from these points after processing. This positioning and movement in the process chamber is achieved by special adjustment devices, so-called pin-lift systems, also called pin lifters.

[0003] Pin lifting systems are particularly used in vacuum chamber systems in the manufacture of ICs, semiconductors, flat panels or substrates, which must be carried out in a protected atmosphere as free as possible from contaminating particles.

[0004] Such a vacuum chamber system includes at least one vacuum chamber, which is provided in particular for accommodating a semiconductor element or substrate to be processed or manufactured, and has at least one or two vacuum chamber openings through which the semiconductor element or other substrate can be guided in and / or out of the vacuum chamber. For example, in a semiconductor wafer or liquid crystal substrate manufacturing line, very delicate semiconductor or liquid crystal elements pass sequentially through several process vacuum chambers, each of which is processed by one processing device.

[0005] Such process chambers often have additional adjustment devices such as transfer valves, the cross section of which is adapted to the substrate and the robot, through which the substrate can be introduced into the vacuum chamber and, if necessary, removed after its intended processing. Alternatively, a further adjustment device (transfer valve) may be provided for removing the processed substrate from the chamber.

[0006] The substrate, e.g., a wafer, is guided, for example, by a properly designed and controlled robot arm, which can move through an opening in the process chamber provided by a transfer valve. The robot arm picks up or grips the substrate, transfers it into the process chamber, and sets it down in a predetermined manner before the process chamber is put into operation. The process chamber can be evacuated in a respective manner.

[0007] For placement of the substrate in the chamber and accurate positioning of the substrate, it is necessary to ensure a relatively high degree of precision and mobility of the substrate, for which purpose the pin lifting system used can provide multiple support points for supporting the substrate, thereby providing load distribution (due to the substrate's own weight) over the entire substrate.

[0008] The substrate is placed by the robot on the extended lifting pins of a lifting system and placed on a carrier, e.g. a potential plate (chuck), by lowering the pins. For this purpose, the robot arm carrying the substrate is usually moved out of the chamber. The pins are further lowered after the substrate is placed and then clear of the substrate, i.e. no longer in contact with it. After the robot arm has moved out and the chamber has been closed (and process gases introduced or vacuum applied), the process step is carried out.

[0009] In particular, the effect of reducing the force on the substrate after the process steps have been performed in the chamber and during the subsequent lifting of the substrate is extremely important. Generally, the substrate has a relatively smooth surface that contacts and rests on the carrier during the placement step. When attempting to remove the substrate from the carrier, the negative pressure acting between the substrate and the carrier may cause a kind of sticking caused, for example, by air pockets. If the substrate is pushed out of the carrier too quickly, the substrate may be damaged at least at some contact points because the contact forces cannot be overcome or released. Moreover, even if contact is established between the lifting pins and the substrate, impacts on the substrate may result in undesirable stresses (or damage). Thus, the application of force to the substrate is an important issue in the handling of the substrate in the chamber.

[0010] At the same time, the aim is to handle the substrate to be processed as gently and carefully as possible and to keep the processing time as short as possible, which means that the substrate can be brought into the desired state, i.e. the loading position, the unloading position and the processing position, in the chamber as quickly as possible.

[0011] For example, to avoid undesired shocks during processing of semiconductor wafers, U.S. Patent No. 6,481,723 B1 proposes the use of special stop means to replace the hard motion stops in pin lifters, which replaces the hard plastic stops with a combination of a soft stop member and a hard stop, which is braked on first contact with the soft stop member and then damped while the soft stop member contacts the hard stop.

[0012] US Patent No. 6,646,857 B2 proposes controlling the lifting action by a detected generated force, the lifting pins being movable according to the received force signal, so that the lifting force at the lifting pins acts on the wafer in a controlled manner at all times.

[0013] A further aspect of the working process under vacuum conditions and with the application of voltages is the possible influence of electrical and / or magnetic interference sources. In such situations, the influence on the mechanical process must be taken into account, especially when designing the lifting system of the pins. For example, US Patent Application Publication 2005 / 0092438 A1 proposes a lifting device in which the lifting pins can be electrically isolated from the control plate by means of a non-conductive material. Summary of the Invention [Problem to be solved by the invention]

[0014] Of course, the component parts moved by the vacuum conditioning device are also exposed to mechanical process influences since they are in the process space, which can result in increased wear and tear on these parts and typically require periodic or on-demand maintenance or replacement.

[0015] In the case of vacuum adjustment devices which are designed as pin lifting devices, the lifting pins are particularly susceptible to these wear effects and must be replaced accordingly.

[0016] In the case of vacuum regulators designed as vacuum valves, the valve closures (valve discs) are particularly subject to process-related wear, which is why these closures are subject to such special maintenance requirements.

[0017] Generally, vacuum valves for adjusting the volumetric or mass flow rate and / or for essentially gas-tight closing of a flow passage led through an opening formed in a valve housing are known from the prior art in various embodiments and are used in vacuum chamber systems in the above-mentioned sector, in particular in the IC, semiconductor or substrate manufacturing sector, which must take place in a protected atmosphere as free as possible from contaminating particles. Both during mechanical processes in the process vacuum chambers and during transfer from chamber to chamber, very sensitive semiconductor elements or substrates must always be in a protected atmosphere, in particular in a vacuum environment.

[0018] For this purpose, on the one hand, pre-ferential valves are used to open or close the gas supply or exhaust, and on the other hand, transfer valves are used to open or close transfer openings in the vacuum chamber for inserting and removing components.

[0019] The vacuum valves through which the semiconductor components pass are called vacuum transfer valves due to the described field of application and associated area, also called rectangular valves due to their mainly rectangular opening cross-sectional shape, and also called slide valves, rectangular slide valves or transfer slide valves depending on their usual mode of operation.

[0020] Preferential valves are used to control or regulate the flow of gas between a vacuum chamber and a vacuum pump or between another vacuum chamber. They are, for example, arranged in a pipe system between a process vacuum chamber or a transfer chamber and a vacuum pump, atmosphere or another process vacuum chamber. The opening cross section of such valves, also known as pump valves, is usually smaller than that of vacuum transfer valves. Preferential valves are also known as regulating valves, since, depending on their area of ​​application, they are not only used to completely open or close the openings, but also to control or regulate the flow rate by continuously adjusting the opening cross section between a fully open position and an airtight closed position. The preferential valve for controlling or regulating the flow of gas can be a pendulum valve.

[0021] In a typical pendulum valve, as known for example from US Pat. No. 6,089,537 (Olmstead), in a first step, a typically circular valve disc is rotatably pivoted through a typically circular opening from a position that releases the opening to an intermediate position that covers the opening. In the case of a slide valve, as described in US Pat. No. 6,416,037 (Geiser) or US Pat. No. 6,056,266 (Brecha), the valve disc is of a similar, typically rectangular shape to the opening, and in this first step, is linearly pushed from a position that releases the opening to an intermediate position that covers the opening. In this intermediate position, the valve disc of the pendulum or slide valve is in a position opposite and spaced from a valve seat that surrounds the opening. In a second step, the distance between the valve disc and the valve seat is reduced, and the valve disc and the valve seat are evenly pressed against each other, substantially sealing the opening in an airtight manner. This second movement is preferably performed in a direction substantially perpendicular to the valve seat. The seal can be achieved, for example, by either a sealing ring located on the closing side of the valve disc, which is pressed against the valve seat surrounding the opening, or by a sealing ring on the valve seat side, which the closing side of the valve disc is pressed against. The closing process, which takes place in these two steps, subjects the sealing ring between the valve disc and the valve seat to almost no shear forces that could destroy it, since the movement of the valve disc in this second step is essentially linear relative to the valve seat.

[0022] The above-mentioned vacuum adjustment devices, in particular the pin lifting system and the vacuum valve, have in common that they are connected to a vacuum space, i.e. a process chamber. In the process space, a specific process atmosphere, in particular a certain internal pressure, is usually set for carrying out a defined mechanical process. This precisely adjusted internal pressure, for example in relation to the process gas used, is part of the process program, i.e. an important parameter for guaranteeing the process quality to be ensured. In other words, the reliability of the internal pressure setting has a corresponding effect on the reliability of the mechanical process.

[0023] To measure and monitor the process atmosphere, pressure sensors are usually used that are located in or connected to the process space. The provision of one or more such pressure sensors at the same time means additional costs in the construction of the vacuum system, in particular with regard to tightness and the avoidance of potential deviations. Moreover, such sensors also represent an additional source of errors in the system, i.e. the failure of one of these sensors may bring the process to a complete halt.

[0024] It is therefore an object of the present invention to provide a solution which avoids the above mentioned drawbacks.

[0025] In particular, it is an object of the present invention to provide an improved vacuum regulation device which helps to avoid the above-mentioned drawbacks.

[0026] The present invention is also based on the object of providing a respective improved vacuum regulator for reliable process execution. [Means for solving the problem]

[0027] These objects are solved by implementing the features of the independent claims. Features which further develop the invention in alternative or advantageous ways can be taken from the dependent claims.

[0028] The present invention is realized based on precise knowledge of the structural design, especially the dynamic behavior of the vacuum regulator, and using such knowledge the device can be further functionally expanded, which allows access to further information about the mechanical process, i.e. providing additional information about the vacuum process without requiring additional components to generate that information.

[0029] More specifically, within the scope of the present invention, the motor of the regulator is operated by control commands and receives current feedback based on the motor's state for further processing, i.e., during operation, the actual state of the motor (e.g., total motor load) is recorded. In addition to this actual state, a corresponding target state (e.g., motor system load) is known for the motor. This target state indicates, for example, how much load the motor should be subjected to under which conditions (e.g., temperature, pressure, humidity, accumulated motor hours, total operating time, etc.).

[0030] Additional information can be obtained from the comparison of the actual state with the target state, thereby indicating the prevailing operating conditions. In particular, a differential pressure can be derived from the difference in the loads or forces thus measured.

[0031] The present invention relates to a vacuum adjustment device for an active element movable in a process atmosphere, in particular in a vacuum region, comprising a coupling designed to couple the active element and a drive unit including an electric motor, the drive unit cooperating with the coupling and designed in such a way that the coupling can be adjusted by the electric motor from a normal position to an active position and back.

[0032] In the normal position, the active element is essentially ineffective with respect to its intended effect in the coupled state (i.e., the active element is connected to a coupling), whereas in the active position, the active element in the coupled state exerts its intended effect (e.g., transporting a substrate or closing a valve opening).

[0033] The vacuum regulating device also has a mechanical interface for connecting the vacuum regulating device to a process space providing a process atmosphere, a dynamic separation device for defining a process atmosphere region by separating the process atmosphere from an external atmosphere region, in which the drive unit is at least partially assigned to the external atmosphere region and the coupling is assigned to the process atmosphere region, and a control processing unit at least electrically connected to the drive unit and designed to control the electric motor.

[0034] In particular, the dynamic decoupling device is coupled or connected to the drive unit and / or the coupling such that when the coupling is adjusted, the decoupling device moves partially accordingly.

[0035] The control processing unit is adapted to derive motor status information based on a magnitude of the received motor operating parameter, where the magnitude of the motor operating parameter depends on at least a total motor load during controlled operation of the electric motor, and the control processing unit has a pressure measurement function, where when the pressure measurement function is performed, a load differential is derived by comparing the motor status information with a known motor target state, where the known motor target state depends on at least a current state of a component of the vacuum regulating device adjustable by the drive unit, and a pressure differential between the external atmosphere area and the process atmosphere area is derived based on the load differential.

[0036] In a particular embodiment, the control and processing unit is designed to derive the absolute pressure in the process atmospheric zone based on this differential pressure. For this purpose, in particular, information about the current pressure in the external atmospheric zone can be used. This information can be obtained by measuring the pressure or as a known quantity.

[0037] This provides a direct pressure measurement inside the vacuum process chamber. The respective measurement may be provided as an output and may also be used, for example, to control or adjust a mechanical process within the process chamber. In particular, the pressure information (absolute or differential pressure) may be taken into account to set or adjust the process pressure.

[0038] In one embodiment, the motor operating parameter is the motor current applied to the electric motor, whereby a measurement of the actual motor current is obtained and input to the control processing unit for processing.

[0039] The motor operating parameter may be embodied as the ratio between the adjustment distance travelled by the coupling and the operating time required for this, in other words the time required for the movement of the coupling may be measured.

[0040] In one design, the control processing unit may be designed such that the motor status information is derived as a drag force acting on the electric motor from the ratio of the travel adjustment distance and the operation time required for it.

[0041] According to the invention, in one embodiment, the motor target state may be a motor target current to be applied to the electric motor in a corresponding adjustment state (operation state), for example the motor current to be applied is known in advance as having a course over a movable adjustment distance of the electric motor or related to the motor rotation speed, in particular the operation time.

[0042] In one design, the known motor target state can be determined at least by a load acting on the drive unit or electric motor via a coupling and / or decoupling device. This load can be measured in part, for example, by the bellows resistance, i.e. the force required to compress the bellows over a defined travel distance, or by the load force of a valve closure or a pin (pin lifting device). This allows the motor target state to be changed within a certain adjustment distance. Such changes are also known and can be measured and stored.

[0043] According to one embodiment, the known motor target state can form a dynamic (changing) reference value over an adjustment distance defined by the adjustable width of the coupling.

[0044] In one design, the known motor target states are: - calibration of the adjustment movement of the coupling within the range of the adjustment distance provided by the adjustment device, in particular as a speed function of the adjustment distance-time, - models describing vacuum regulators, in particular digital computer models; - simulating the adjustment conditions in a range of adjustment distances defined by the adjustment width of the coupling, or - the average value of the load and / or force measured during repeated cycles of the reference movement is determined by.

[0045] In one embodiment, a drive unit can interact with the separating device such that the separating device is adjustable from a normal position to an active position and back by an electric motor. For example, the separating device can be directly connected to the drive unit or indirectly connected to the drive unit, for example via a coupling.

[0046] The dynamic separating device can in particular be designed as a bellows or seal, in particular as a diaphragm bellows or diaphragm seal, so that the separating device provides a dynamic seal which provides a sealing effect even when moved within a certain distance.

[0047] The adjustment device is especially designed for use in a vacuum region, with one part of the adjustment device operating within the vacuum region and another part, preferably a part of the drive unit, being outside the vacuum region. A separation device for atmospheric separation of these two regions may also be provided by the drive unit for this purpose and may be formed, for example, by a housing or a bellows of the drive unit.

[0048] Alternatively, the separating device may comprise a coupling, the coupling being arranged to move partially or completely outside the vacuum range. The separating device may for example be connected to a chamber wall of the process chamber.

[0049] The separating device can also be designed, for example, as a sliding bushing sealed with an O-ring.

[0050] The drive unit may be designed for movement on a linear axis of the coupling along and / or parallel to an adjustment axis.

[0051] According to an embodiment of the present invention, the active element may be realized as a lifting pin of a pin lifting device or as a valve closure of a vacuum valve.

[0052] According to one embodiment, the vacuum adjustment device is a pin lifting device, in particular a pin lifter for moving and positioning a substrate, in particular a wafer, to be processed in a process atmosphere region that can be provided by a vacuum process chamber, in particular having said coupling as a first coupling of a plurality of couplings.

[0053] Here, the drive unit provides at least linear adjustment of the first coupling, the active position being made as a mounting position for mounting the pin lifting device to the substrate, and the coupling being designed to receive lifting pins designed to contact and support the substrate and form an active element, the intended effect of which (the lifting pins) is the transport, lifting and lowering of the processed substrate.

[0054] The normal position provided by the linear movement capability of the first coupling is represented in particular by the lowered position of the lifting pins, which are not in contact with the substrate.

[0055] In a further embodiment, the vacuum regulator can be designed as a vacuum valve, in particular a vacuum slide valve, pendulum valve or monovalve, for controlling the volumetric or mass flow rate and / or for tightly blocking a flow path, which comprises a valve seat with a valve opening defining an opening axis and a first sealing surface surrounding said valve opening, and a valve closure forming an active element for controlling the volumetric or mass flow rate and / or for blocking a flow path (intended effect), in particular a valve disc, with a second sealing surface corresponding to said first sealing surface.

[0056] The valve closure is connected to a drive unit by a coupling and is adjustable from an open position, as a normal position in which the valve closure and the valve seat of the vacuum valve face each other without contact, to a closed position, as an active position in which the first sealing surface and the second sealing surface come into sealing contact via an interposed seal, thereby hermetically closing the valve opening, and back. The coupling is designed to receive the valve closure.

[0057] The device according to the invention is explained in more detail below by means of specific embodiments which are shown diagrammatically in the drawings by way of example only, and in which further advantages of the invention are also discussed. [Brief description of the drawings]

[0058] [Figure 1] FIG. 1 shows a schematic diagram of one embodiment of a vacuum processing system for wafers including a vacuum conditioning apparatus according to the present invention. [Diagram 2] FIG. 2 shows an embodiment of the vacuum adjustment device according to the invention, designed as a pin lifting device. [Diagram 3] FIG. 3 shows a further embodiment of a vacuum adjustment device according to the invention, designed as a pin lifting device. [Figure 4] FIG. 4 shows an embodiment of a vacuum regulator according to the invention, designed as a vacuum valve. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0059] FIG. 1 shows a schematic process setup for processing a semiconductor wafer 1 under vacuum conditions. The wafer 1 is transferred by a robot arm 2 into a vacuum chamber 4 (process atmosphere P) via a first vacuum transfer valve 5a of the vacuum adjustment device and positioned by lifting pins 7 of a pin lifting device (three pins are shown) of the vacuum adjustment device designed according to the invention. The wafer 1 is then picked up or placed on the pins 7 and the robot arm 2 moves out. The pins of the pin lifting device are then in their extended carrying position. The wafer 1 is usually placed on a carrier device provided on the robot arm or on the robot arms 2, 3 or is held by a special carrier device. After the wafer 1 has been picked up by the pins 7, the robot arm is guided out of the chamber 4, the transfer valve 5a is closed and the pins 7 are lowered (to their normal position). This is done by a device 6 of the pin lifting device connected to each pin 7. In this way the wafer 1 is placed on the four carrier elements 8 shown.

[0060] In this state, the desired process (e.g. coating) on ​​the wafer 1 is carried out under vacuum conditions, in particular under a defined atmosphere (i.e. process gas at a defined pressure). For this purpose, the chamber 4 is connected to a vacuum pump and preferably has a vacuum regulating valve (not shown) for regulating the chamber pressure.

[0061] After processing, the wafer 1 is lifted again by the pin lifting device to a removal position (carrying position) and is then transferred to a second transfer valve 5b by the second robot arm 3. Alternatively, the process can be designed with only one robot arm, in which case loading and unloading can be performed via a single transfer valve.

[0062] FIG. 2 shows an embodiment in which the vacuum adjusting device according to the present invention is a pin lifting device 10 .

[0063] The lifting pin 19 is locked to the coupling 18 of the device 10. The lifting pin 19 preferably comprises a metallic, polymer-based or ceramic material, in particular if the entire pin 19 is made of such a material. The locking of the coupling 18 can be realised, for example, magnetically or by means of a clamp.

[0064] The coupling 18 is movable in the z-direction by means of the slide 14. For this purpose, the slide 14 is coupled to a threaded spindle 13, which is driven by the motor 12 of the drive unit.

[0065] Any thermal and electrical insulation between the upper coupling part and the lower drive part is realized in one variant by a first insulating element 16, which thermally and electrically separates the upper and lower housing parts. A second insulating element, preferably embodied by the slide 14, may also be provided. In this variant of the pin lifting device 10, the threaded spindle 13 is precisely and rigidly designed and mounted in such a way that there is no (electrically and thermally conductive) contact between the spindle 13 and the coupling 18 (even if there is a relative movement). Alternatively, the spindle 13 is made of or coated with a non-conductive or heat insulating material. This provides a complete electrical and thermal insulation between the upper and lower parts in all states of the device 10. In yet another variant, both the threaded spindle 13 and the slide 14, which is seated on the spindle 13, can be electrically conductive (for example metallic). Insulation can then be realized in particular by an intermediate sleeve between the spindle / slide and the coupling, for example.

[0066] It will be understood that the electrical isolation described above is purely optional and the invention extends to embodiments without such isolation.

[0067] Pin lifter 10 also includes an internal bellows 15 that is positioned and configured to provide atmospheric separation between a process atmosphere region P, where pins 19 (pins) reside and where mechanical processes typically occur, and an exterior atmosphere region A, where, for example, drive 12 and other surrounding components reside. Bellows 15 compresses upon extension of pins 19 while maintaining the atmosphere separation.

[0068] In the illustrated variant, the adjustment slide 14 moves both the coupling 18 and the bellows 15, both of which are at least indirectly connected to the slide. In particular, the slide 14 is connected to the coupling 18, which in turn is connected to the bellows 15, the second end of which is also connected to the housing of the pin lifting device.

[0069] The connections of the individual components are made in a particularly gas-tight manner.

[0070] The pin lifting apparatus 10 is connected to a housing 20 of a vacuum process chamber. This connection is designed so that the internal process atmosphere of the process chamber also influences the inside of the pin lifting apparatus 10. Feed-throughs in the housing wall 20 provided for the pins 19 ensure that the process atmosphere extends into the lifter 10, i.e. the process space and part of the internal space of the pin lifter 10 form a common process atmosphere region P.

[0071] The process atmosphere area P is defined in the pin lifting device 10 by at least the bellows 15. The inner bellows space defined by the bellows 15 is part of the process atmosphere area P. Furthermore, the movement, particularly in the axial direction, is restricted at the lower part of the coupling 18. The atmosphere area separated from the process atmosphere area P is essentially the outer atmosphere area A.

[0072] In the process atmosphere region P, there is usually a significantly lower pressure than in the external atmosphere region A. Thus, also in the process atmosphere region P of a vacuum process chamber, there is a very low pressure, in particular a low pressure for mechanically processing the workpiece. Vacuum conditions usually prevail there. During operation of the pin lifting device 10, it can be assumed that there is a large pressure difference between the process atmosphere P and the external atmosphere A.

[0073] The present invention utilizes this pressure difference.

[0074] To move the movable system components, in this case the coupling 18 and the bellows 15, the electric motor 12 has to overcome system loads occurring in these components. These loads depend on the structural design (e.g. mass), the movement characteristics (friction, etc.) and the current state (e.g. position, bellows compression, etc.) of the components. This motor system load (motor target state) may be known for the pin lifter 10 or measured by calibration and may be stored in the control system. For this purpose, a look-up table, a model describing the pin lifter 10 sufficiently accurately or a motor teaching process (repeating, monitoring, comparing, recording the motor operation sequence) may be used. The motor system load thus describes the respective target state of the electric motor during operation under defined conditions, taking into account, among other things, environmental conditions such as pressure, temperature, etc.

[0075] A control processing unit is provided for operating the lifter 10 (not shown). Appropriate signals (motor control signals) are provided to the motor 12 for target control, e.g., movement to a predefined pin position. Motor operating parameters are provided for operating the motor 12. The range of motor operating parameters over which the electric motor is operating depends on the total motor load, i.e., represents the load currently being applied to the motor 12. For example, the motor operating parameter may be the motor current applied to the motor at any one time.

[0076] The control processing unit is configured to derive motor status information from the motor operating parameters, i.e. to quantify, for example, the current motor load or the current motor current, and thus determine the actual status of the electric motor.

[0077] This actual state can then be related to a known motor target state, i.e., the motor state information can be compared to a known motor system load (motor target state). Based on accurate knowledge of the motor system load, a load delta can be derived, i.e., the difference between the target load and the actual load.

[0078] From the difference in load thus obtained, the differential pressure between the external atmospheric zone (A) and the process atmospheric zone (P) is derived. By knowing the atmospheric pressure present in the external atmospheric zone (A), the absolute pressure in the process atmospheric zone (P), i.e., the process chamber, can be measured.

[0079] Thus, in accordance with the present invention, the vacuum regulator provides enhanced capabilities for pressure measurement.

[0080] A (continuous) comparison of current motor operating parameters against stored reference functions (motor system loads) also allows for process monitoring and recording of the state of the process space. For example, if a maximum allowable deviation is exceeded, a corresponding signal can be generated and output to indicate an unacceptable system state and, if necessary, recommend a system check.

[0081] Long-term monitoring of motor operating parameters can be used to determine both the wear of one or more components of the pin lifting device and the process quality. In this way, by observing the repetition of similar process steps (process cycles) over time, trends of changes in the process can also be detected. Trend monitoring also allows prediction of future system conditions and the development of correspondingly optimized maintenance cycles.

[0082] 3 illustrates one embodiment of a pin lifting device 30 according to the present invention, which is shown in a lowered, normal position.

[0083] FIG. 3 shows a drive unit of the pin-footing device 30 with a motor 32 (electric motor). The motor 32 can be, for example, a servo motor or a stepper motor. The drive unit is coupled to a shaft, here designed as a spindle 33, i.e. the shaft 33 can be rotated by the motor 32. This rotation can be controlled or regulated in a managed manner, for example according to a given number of revolutions. A controlled movement is possible, for example with an encoder, which provides a control variable, for example about the axial position of the bearing pin. In the illustrated example, the spindle 33 has an external thread. This thread can be designed as a trapezoidal, acute or round thread. Thus, by controlling the motor 32 accordingly, a threaded rod 33 (spindle) can be rotated.

[0084] The pin lifter 30 according to the invention also comprises a sliding guide element 31. The sliding guide element 31 has a central recess which extends in the axial direction of the sliding guide element 31, here coaxially with the adjustment axis V. This recess is provided with an internal thread. The internal thread can be, for example, machined directly into the sliding guide element 31, i.e. into the material of the sliding guide element 31. Alternatively, the recess can comprise, for example, a sleeve with an internal thread.

[0085] The sliding guide element 31 is coupled with its internal thread to the external thread of the spindle 33, i.e. the external thread and the internal thread correspond and interact with each other. The external thread meshes with the internal thread. The spindle 33 is directly coupled only to the sliding guide element 31 as a moving element. In other words, the spindle connects the drive 32 to the sliding guide element 31, in particular only to the sliding guide element 31.

[0086] This interaction allows the sliding guide element 31 to be moved in the forward and backward direction along the adjustment axis V by rotating the spindle 33. This movement can thus be performed axially along the adjustment axis V. For this purpose, the sliding guide element 31 can be mounted in such a way that it is substantially incapable of performing a rotational movement about said adjustment axis, but can only be moved axially.

[0087] The sliding guide element 31 is also connected to a coupling 38 of the pin lifting device 30, so that the coupling 38 can move axially in the same manner as the sliding guide element 31, in particular from a lowered normal position as shown in the figure to an extended carrying position.

[0088] The coupling 38 has a receptacle 37 for receiving a lifting pin. Such a lifting pin is preferably designed to contact and support a substrate (e.g. a semiconductor wafer). The receptacle 37 is provided with a ring or a helical spring, which clamps the lifting pin in the coupling 38. However, the receptacle can also have other locking means (retaining ring, magnet, screw, etc.). The lifting pin can be inserted from above along the axis V through an opening provided for this purpose in particular in the receptacle 37 of the coupling 38.

[0089] The sliding guide element 31 thus forms a connecting element as a means for ultimately displacing the lifting pin by the drive.

[0090] By selecting an appropriate material, the movement of the sliding guide element 31 can be performed with low friction and without lubrication. For example, PTFE or other non-stick material can be selected as the manufacturing material or surface coating. The sliding guide element 31 and / or its inner surface can comprise this material.

[0091] The pin lifter 30 also has a bellows 35 as an atmosphere separation device. The upper end of the bellows 35 is indirectly (for example, by a housing seal mounted on the top) or directly connected to the housing of the pin lifter 30. The upper end of the bellows 35 is connected to a coupling 38 (at the base of the coupling 38). Each connection is made in an airtight manner. The internal volume or axial extension of the bellows 35 can be varied while maintaining the atmosphere separation, in particular between the process atmosphere and the external atmosphere.

[0092] The bellows 35 and the coupling 38 are connected such that the coupling 38 provides a one-sided atmospheric seal for the bellows 35. Thus, a process atmosphere region P is defined by the bellows 35 and the coupling 38.

[0093] As a result of this arrangement, by driving the spindle 33, the coupling 38 together with the bellows 35 can be moved linearly within the pin lifting device 30.

[0094] The pin lifting device 30 is connected to the process chamber 20 by a threaded connection or flanged, whereby the internal volume of the pin lifter 30, bounded by each side of the bellows 35 and the coupling 38, extends the volume of the process chamber, which forms a process atmosphere region P. This is separated in an airtight manner from the external atmosphere region A.

[0095] The pin lifting device 30 has a control processing unit and algorithms corresponding to the embodiment shown in FIG. 2, i.e., the pin lifting device 30 is designed to measure between the process atmosphere region P and the external atmosphere region A based on detectable motor operating parameters.

[0096] FIG. 4 shows another embodiment in which the vacuum regulator 40 according to the invention is a vacuum slide valve. The vacuum slide valve 40 has a valve housing with an opening 42 with an opening axis O and an elongated, substantially rectangular valve seat 43 in the valve wall surrounding the opening 42. A closure element 50, which has a closing side, in particular on the process side, has a cross section slightly larger than the opening 42 and closes the opening 42 substantially gas-tight by pressing its closing side against the valve seat 43. The closure element 50 is supported by two valve rods 46 arranged parallel to each other. The closure element 50 is connected to the valve rods by a coupling. This connection can be realized by screwing or clamping. Since FIG. 4 shows a side view of the valve rods, only one valve rod 46 is visible. According to another embodiment according to the invention, the closure element 50 may be supported by only a single valve rod 46.

[0097] The valve housing separates a vacuum region 51 in which the opening 42 , valve seat 43 and closure plate 50 are located, and an actuation region 52 which is outside the vacuum region 51 .

[0098] The two valve rods 46 are inserted through two gas-tight feedthroughs, designed as diaphragm seals or diaphragm bellows 45 and with seals (e.g. O-rings) at their ends, in the valve housing from the vacuum region 51 to the actuation region 52. The diaphragm seals or diaphragm bellows 45 are designed to allow the valve rods 46 to move along the longitudinal and lateral axes within a certain range of movement while maintaining a gas-tight seal.

[0099] The driving area 52 is separated in an airtight manner from the vacuum area 51, so that atmospheric pressure prevails in the driving area 52. Friction particles in the driving area 52 cannot enter the delicate vacuum area. A drive unit with a motor is arranged in the driving area 52.

[0100] The drive unit is designed to move the two valve rods 46 from an open position along a longitudinal axis in a vertical closing direction z to an intermediate position, and to adjust the two valve rods 46 back and forth from an intermediate position to a closed position along a horizontal axis in a horizontal closing direction y extending perpendicular to the longitudinal axis, thereby moving the closure plate 50 from an open position to the intermediate position shown (the closure plate is L-shaped, hence the term L-shaped).

[0101] The vacuum slide valve 40 or its opening 42 is designed to connect to a vacuum process chamber. The process atmosphere in this chamber extends up to and includes the vacuum region 51 of the vacuum slide valve 40. In other words, a process atmosphere region P is formed that includes at least both the space of the vacuum chamber and the vacuum region 51 of the vacuum slide valve 40. This process atmosphere region P is separated from the external atmosphere region A by a sealed bellows 45. The actuation region 52 is part of the external atmosphere region A.

[0102] The vacuum slide valve 40 has a control and processing unit designed and constructed to be able to measure the differential pressure between the process atmosphere P and the external atmosphere A. For this purpose, a known target system load (target state of the valve) is compared during operation with the currently provided operating parameters (e.g. applied motor current). The differential pressure can be deduced from the load difference thus derived.

[0103] Since the pressure in the process atmospheric region P is lower than the pressure in the external atmospheric region A, for example, the greater the pressure difference, the smaller the current operating load during the closing operation.

[0104] Therefore, the differential pressure can be derived based on the load differential, in particular by pre-calibration of the system, i.e. by determining a function that describes the relationship between the motor load differential and the ambient pressure differential.

[0105] Finally, this concept can also be used to measure the absolute process pressure (if the existing pressure in the external atmospheric region A is known) and therefore can also be used for process monitoring in vacuum mechanical processes.

[0106] It is understood that the shown figures only diagrammatically illustrate possible embodiments: according to the invention different approaches can be combined with each other, in particular vacuum devices for substrate processing (e.g. pin lifters) or prior art vacuum valves.

Claims

1. A vacuum adjustment device (5a, 5b, 6, 10, 30, 40) for an active element (7, 19, 50) movable in a process atmosphere region (P), in particular in a vacuum region, a coupling (18, 38) designed to couple said active elements (7, 19, 50); A drive unit having an electric motor (12, 32), which is driven by the electric motor: From a normal position in which the active elements (7, 19, 50) are in an essentially ineffective coupling state with respect to their intended effect, to an adjustable return active position in which the active element (7, 19, 50) in coupled state exerts its intended effect; a drive unit connected to said coupling (18, 38) and designed such that said coupling (18, 38) is adjustable; a mechanical interface for connecting said vacuum regulating device (5a, 5b, 6, 10, 30, 40) to a process space providing a process atmosphere; a dynamic separation device (15, 35, 45) for separating a process atmosphere from an external atmosphere area (A) thereby defining said process atmosphere area (P), wherein said drive unit is at least partially assigned to said external atmosphere area (A) and said coupling (18, 38) is assigned to said process atmosphere area (P); a control and processing unit at least electrically connected to said drive unit and designed to control said electric motor (12, 32); having The control processing unit: a pressure measuring function configured to derive motor status information based on a magnitude of a motor operating parameter that depends on at least a total motor load during controlled operation of the electric motor; Here, the pressure measurement function unit is deriving a load differential by comparison of motor state information to known motor target states, the load differential depending on at least a current state of the components of the vacuum adjustment device (5a, 5b, 6, 10, 30, 40) that are adjustable by the drive unit; It is designed to derive the pressure difference between the external atmosphere region (A) and the process atmosphere region (P) from the load difference. A vacuum adjusting device (5a, 5b, 6, 10, 30, 40).

2. 2. The vacuum regulating device (5a, 5b, 6, 10, 30, 40) according to claim 1, characterized in that the motor operating parameter is a motor current applied to the electric motor (12, 32).

3. 3. Vacuum adjustment device (5a, 5b, 6, 10, 30, 40) according to claim 1 or 2, characterized in that the motor operating parameter is embodied as the ratio between the adjustment distance travelled by the coupling (18, 38) and the operating time required therefor.

4. 4. The vacuum adjusting device (5a, 5b, 6, 10, 30, 40) according to claim 3, characterized in that the control processing unit is designed such that the motor status information is derived as a resistance force acting on the electric motor from the ratio between the moving adjustment distance and the operating time required for it.

5. Vacuum regulating device (5a, 5b, 6, 10, 30, 40) according to any one of claims 1 to 4, characterized in that the known motor target state is a motor target current to be applied to the electric motor (12, 32) in a corresponding regulating state.

6. The vacuum regulating device (5a, 5b, 6, 10, 30, 40) according to any one of claims 1 to 5, characterized in that the known motor target state is defined at least by the load acting on the coupling (18, 38) and / or the decoupling device (15, 35, 45) of the drive unit or the electric motor.

7. The vacuum adjusting device (5a, 5b, 6, 10, 30, 40) according to any one of claims 1 to 6, characterized in that the known motor target state forms a dynamic reference value over an adjustment distance defined by an adjustment width of the coupling (18, 38).

8. The known motor target state is Adjustment of the movement of the coupling, in particular its calibration as a function of the movement / movement time; a model describing the vacuum regulator; Simulation of the adjustment conditions over an adjustment distance defined by the adjustment width of the coupling (18, 38), or The average value of the load and / or force measured during repeated cycles of the reference movement The vacuum regulating device (5a, 5b, 6, 10, 30, 40) according to any one of claims 1 to 7, characterized in that it is determined by:

9. The vacuum adjusting device (5a, 5b, 6, 10, 30, 40) according to any one of claims 1 to 8, characterized in that the drive unit interacts with the separating device (15, 35, 45) such that the separating device (15, 35, 45) is adjustable by the electric motor from the normal position to the active position and back.

10. Vacuum regulating device (5a, 5b, 6, 10, 30, 40) according to any one of claims 1 to 9, characterized in that the dynamic separating device (15, 35, 45) is designed as a bellows (15, 35, 45) or a seal, in particular a diaphragm bellows or a diaphragm seal.

11. Vacuum adjustment device (5a, 5b, 6, 10, 30, 40) according to any one of claims 1 to 10, characterized in that the drive unit is designed for movement on a linear axis of the coupling (18, 38) along and / or parallel to an adjustment axis (V).

12. Vacuum regulating device (5a, 5b, 6, 10, 30, 40) according to any one of claims 1 to 11, characterized in that the active element (7, 19, 50) is designed as a support pin (7, 19) or a valve closure (50).

13. A vacuum regulator (5a, 5b, 6, 10, 30, 40) according to any one of claims 1 to 12, said vacuum adjustment device (5a, 5b, 6, 10, 30, 40) being a pin lifting device (6, 10, 30), in particular a pin lifter for moving and positioning a substrate (1) to be processed, in particular a wafer, provided at least in a process atmosphere region (P) which can be provided by a vacuum process chamber, the pin lifting device has the coupling (18, 38) as a first coupling of a plurality of couplings, Where: the drive unit provides linear adjustment of the first coupling (18, 38); the active position being a mounting position for mounting the pin lifting device (6, 10, 30) to the substrate (1); The coupling (18, 38) is designed to receive lifting pins (7, 19) designed to contact and support the substrate (1) and form active elements. A vacuum adjusting device (5a, 5b, 6, 10, 30, 40).

14. A vacuum regulator (5a, 5b, 6, 10, 30, 40) according to any one of claims 1 to 12, said vacuum regulating device (5a, 5b, 6, 10, 30, 40) is designed as a vacuum valve (40), in particular as a vacuum slide valve, pendulum valve or monovalve, for controlling the volumetric or mass flow rate and / or for sealingly blocking a flow path, a valve seat (43) including a valve opening (42) defining an opening axis (O) and a first sealing surface surrounding the valve opening (42); a valve closure (50) forming said active element (7, 19, 50), in particular a valve disc, for controlling a volumetric or mass flow rate and / or for blocking a flow path, said valve closure (50) having a second sealing surface corresponding to said first sealing surface; having wherein the valve closure (50) is From a normal open position in which the valve closure (50) and the valve seat (43) of the vacuum valve (40) face each other without contacting each other, connected to the drive unit by the coupling such that the first and second sealing surfaces are in sealing contact via an interposed seal, whereby the valve opening (42) is adjustable to and back to a closed position as a gas-tightly closed active position; and The coupling is designed to receive the valve closure (50). A vacuum adjusting device (5a, 5b, 6, 10, 30, 40).

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