Vacuum valve for providing symmetrical fluid flow

Abstract

To provide a regulating vacuum valve which provides accurate adjustment or regulation of a flow through a valve opening and further provides a uniform flow through the valve opening.SOLUTION: The present invention relates to a regulating vacuum valve 10 for adjusting a volume flow rate or a mass flow rate and shutting off a flow path in an airtight manner, which includes a first valve opening 11a defining a first opening axis, a first valve seat, a first valve disk 13a. The valve further includes a drive unit that is configured so that the first valve disk 13a can be adjusted at least from an open position to a closed position and in a return direction, and that is coupled to the first valve disk 13a. The regulating vacuum valve 10 has a second valve opening 11b defining a second valve axis, and a second valve seat. In addition, a second valve disk 13b is provided. An overall valve opening of the regulating vacuum valve is formed by the first valve opening as a first valve partial opening 11a and the second valve opening as a second valve partial opening 11b.SELECTED DRAWING: Figure 1a

Description

[Technical Field]

[0001] Background technology The present invention relates to a regulating vacuum valve having a plurality of valve discs and a corresponding plurality of valve portion openings.

[0002] Generally, vacuum valves for adjusting the volumetric or mass flow rate and for essentially gas-tightly closing a flow path leading through an opening formed in a valve housing are known in various embodiments of the prior art and are used in particular in vacuum chamber systems in the field of IC, semiconductor or substrate manufacturing, which must be carried out in a protected atmosphere and preferably without the presence of contaminating particles.

[0003] Such a vacuum chamber system includes at least one evacuable vacuum chamber, which is provided to receive semiconductor elements or substrates to be processed or manufactured, and has at least one vacuum chamber opening for transferring the semiconductor elements or other substrates into and out of the vacuum chamber, and at least one vacuum pump for evacuating the vacuum chamber. For example, in a semiconductor wafer or liquid crystal substrate production plant, sensitive semiconductor elements or liquid crystal elements pass sequentially through several process vacuum chambers, where the components placed in the process vacuum chambers are each processed by a processing device. During the processing process in the process vacuum chambers and during transport from chamber to chamber, the sensitive semiconductor elements or substrates must always be in a protected atmosphere, especially an airless environment.

[0004] For this purpose, peripheral valves are used to open or close gas inlets or outlets, and transfer valves are used to open or close transfer openings in the vacuum chamber for inserting and removing parts.

[0005] The vacuum valves through which the semiconductor components pass are called vacuum transfer valves because of the above-mentioned fields of application and associated dimensions, rectangular valves because their opening cross-section is approximately rectangular, and slide valves, rectangular slide valves or transfer slide valves because of their normal mode of operation.

[0006] On the other hand, peripheral valves are used, in particular, to control or regulate the flow of gas between a vacuum chamber and a vacuum pump or another vacuum chamber. Peripheral valves 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 called pump valves, is usually smaller than that of vacuum transfer valves. Peripheral valves are also called regulating valves, since, depending on the application, they are used not only to completely open or close the opening, but also to control or regulate the flow rate by continuously adjusting the opening cross-section between a fully open position and an airtight position. One possible peripheral valve for controlling or regulating gas flow is a pendulum valve.

[0007] In a typical pendulum valve, known from U.S. Pat. No. 6,089,537 (Olmsted), the first step involves rotating a typically circular valve disc through a typically circular opening from a position that opens the opening to an intermediate position that covers the opening. In the case of slide valves, such as those described in U.S. Pat. No. 6,416,037 (Geiser) and U.S. Pat. No. 6,056,266 (Blecha), the valve disc and opening are typically rectangular, and this first step involves linearly compressing the disc from a position that opens the opening to an intermediate position that covers the opening. In this intermediate position, the valve disc of a pendulum or slide valve is positioned a short distance away from a valve seat surrounding the opening. In a second step, the distance between the valve disc and the valve seat is reduced, so that the valve disc and the valve seat are evenly pressed against each other, essentially sealing the opening. This second movement is preferably performed in a direction substantially perpendicular to the valve seat. Sealing can be achieved, for example, by a sealing ring located on the closing side of the valve disc, which presses against a valve seat surrounding the opening, or by a sealing ring on the valve seat, which the closing side of the valve disc presses against. Because of this two-step closing process, the sealing ring between the valve disc and the valve seat is hardly subjected to shear forces that would destroy it, since the movement of the valve disc in the second step is essentially in a straight line perpendicular to the valve seat.

[0008] Various sealing devices are known from the prior art, for example from U.S. Patent No. 6,629,682 (B2) (Duelli). Suitable materials for sealing rings and seals in vacuum valves are, for example, fluororubbers, also known as FKM, in particular the fluoroelastomers known under the trade name "Viton", and perfluororubbers, abbreviated as FFKM.

[0009] The above-described multi-stage movement, in which the closure member is first pressed laterally over the opening without contact between the seal and the valve seat and then the closure member is pressed essentially vertically over the valve seat, not only offers the advantage that the seal is pressed almost exclusively vertically without lateral or longitudinal loading of the seal (avoidance of particles), but also the possibility of regulating the flow rate of the medium (such as process gas) through the valve opening.

[0010] Since the above valves are used in particular in the manufacture of sensitive semiconductor devices, particle generation caused in particular by valve actuation and mechanical loads on the valve closure members, as well as the number of free particles in the valve chamber, must, as already mentioned, be kept as low as possible. Particle generation is primarily the result of friction, e.g., due to metal-to-metal contact and wear.

[0011] As mentioned above, regulating vacuum valves are used to set a defined process environment in a process chamber. The regulation is usually based on a pressure signal providing information about the internal chamber pressure and a target value to be achieved by the regulation, i.e., the target pressure. The position of the valve closure (valve disc) is then changed within the framework of the regulation so that the target pressure is reached within a specific period of time.

[0012] The above-mentioned embodiments have in common that, especially in the case of adjustment, the adjustment curve (volumetric flow rate over unit time) resulting from one of these structures usually occurs with an unfavorable curve progression. In particular, the curve at the transition from a nearly closed valve state to a fully closed valve state shows a clearly uneven curve progression due to the "snap effect" that occurs in this process, where the flow through the opening is suddenly blocked. This makes fine adjustment at very low pressures very difficult or impossible.

[0013] Another important factor related to semiconductor manufacturing is the use and handling of process gases required for the individual processing steps. Regulating valves typically also serve the function of providing a defined gas concentration, i.e., adjusting the gas concentration by variable gas outflow through the valve. The process gas is typically supplied on the side of the process chamber opposite the exhaust opening.

[0014] In addition to the gas concentration and atmospheric pressure, the most uniform possible distribution of the process gas is also advantageous here, at least in the region of the substrate to be processed. A gas flow that is as symmetrical as possible, i.e., through the process chamber both during gas addition and during evacuation, can be helpful in this regard.

[0015] US Patent No. 6,994,311 (B2) discloses a regulating vacuum valve intended to generate a symmetrical flow through an opening in the open valve position. The valve disc is suspended centrally on a guide (valve rod) and can be guided axially so that the volumetric flow rate through the opening can be adjusted as a function of the distance between the valve disc and the valve seat.

[0016] However, the disadvantage of this solution is that there must still be a mechanical connection to the center of the valve opening to guide the valve disc, which at least partially breaks the flow symmetry and leads to turbulence at the connecting element. Summary of the Invention

[0017] The present invention is therefore based on the object of providing a regulating vacuum valve which, on the one hand, provides precise adjustment or regulation of the valve opening and thus of the flow through the opening, and, on the other hand, provides a uniform flow through the valve opening.

[0018] In particular, it is an object of the present invention to provide the above improvements with a relatively short valve closure adjustment time.

[0019] This object is solved by implementing the features of the independent claims. Features which further develop the invention in alternative or advantageous ways can be seen from the dependent claims.

[0020] The present invention relates to a vacuum valve, in particular a regulating vacuum valve, structure that provides improved flow rate and outflow of process fluid from a process volume with respect to uniformity of flow behavior, while at the same time significantly improving, i.e., shortening, the adjustment time for changing from an open state to a closed state (or vice versa).

[0021] The above advantages and improvements are provided by subdividing the single valve opening known in the prior art into multiple valve sub-openings in a vacuum valve. The sub-openings are arranged symmetrically about a central valve axis. Each valve sub-opening is provided by a valve seat and is surrounded by a sealing surface. The sum of the areas of the multiple valve sub-openings equals the area of ​​the overall valve opening.

[0022] The cross section of the total valve opening is the sum of the cross sections of the openings of the valve part openings, which cross section depends on the respective opening state of the valve part openings, i.e. the flow area released by the respective valve closures.

[0023] By similarly dividing the valve openings of the valve closures (valve discs) and the associated structures, it is possible to provide a structure in which the valve closures do not cover the respective valve openings, or at least do not cover them to the maximum extent possible, in the open position, i.e., when the maximum flow rate (volume flow rate) is provided. In other words, the valve discs can be adjusted so that the valve openings are substantially, in particular completely, uncovered. In the open position, the valve closures can be completely or substantially completely removed from the flow path connecting the first and second ports of the regulating vacuum valve.

[0024] By removing the valve closure from the flow path, the mechanical elements required to couple the valve closure within the flow path can be avoided. Thus, there are no moving or mechanical parts in the flow path in the open position. In the open position, there is only a structurally fixed structure that defines the valve seat. However, this fixed structure can also be advantageously designed to have a shape and dimensions that are symmetrical about the central axis. Such a design can provide highly symmetrical flow through the valve in all open conditions.

[0025] The vacuum valve according to the invention has a drive device which comprises at least one drive element, in particular several drive elements corresponding to several valve closures, which can be designed, for example, as a motor.

[0026] The present invention thus relates to a regulating vacuum valve for regulating a volumetric or mass flow rate and blocking a flow path in a gas-tight manner, the regulating vacuum valve having a first valve seat with a first valve opening defining a first opening axis and a first sealing surface surrounding the first valve opening, and a first valve disc having a first contact surface corresponding to the first sealing surface.

[0027] The regulating vacuum valve further comprises a (e.g., electrically operated) drive device coupled to the first valve disc, which is designed so that the first valve disc can be adjusted at least from an open position, in which the first valve disc and the first valve seat are not in contact with each other, to a closed position, in which there is axially sealing contact between the first sealing surface and the first contact surface via the intermediate sealing element, so that the first valve opening is closed in an airtight manner, and vice versa.

[0028] According to the present invention, the regulating vacuum valve includes at least one second valve seat having a second valve opening defining a second opening axis and a second sealing surface surrounding the second valve opening. The valve further includes a second valve disc having a second contact surface corresponding to the second sealing surface. Thus, the entire valve opening of the regulating vacuum valve is formed by the first valve opening as the first valve portion opening and the second valve opening as the second valve portion opening.

[0029] The provision of at least two groups, each comprising at least one valve seat and one valve closure, allows a symmetrical arrangement relative to the center of the vacuum valve, and overlapping of the valve openings with the valve closures in the open position can be avoided at least to a large extent, thus providing, on the one hand, a symmetrical volume flow through the valve and, on the other hand, a relatively fast actuation (i.e., fast adjustment of the valve closures due to their relatively small individual mass) together with the possibility of achieving a very flexible volume flow regulation, i.e., a relatively large overall opening cross-section from the closed position (and vice versa) in a short time.

[0030] In one embodiment, the regulating vacuum valve has a third valve opening defining a third opening axis, a third valve seat having a third sealing surface surrounding the third valve opening, and a third valve disc having a third contact surface corresponding to the third sealing surface, where the overall valve opening is then further defined by the third valve opening as a third partial valve opening.

[0031] By arranging a third or further combination of valve seats and valve discs, symmetry of the valve opening about the central axis of the valve can be achieved, thereby further increasing the symmetry (concentricity) of the volumetric flow through the valve.

[0032] In particular, the drive device can be coupled to the second valve disc, in particular to the third valve disc, in such a way that the coupled valve disc can be adjusted at least from a respective open position, in which the respective valve disc and the respective valve seat are not in contact with each other, to a closed position, in which there is axially sealing contact between the respective sealing surfaces and the respective contact surfaces via the respective sealing elements located therebetween, thereby closing the respective valve part openings in an airtight manner, and back again.

[0033] In one embodiment, the regulating vacuum valve can have a coupling arrangement that provides a mechanical coupling between the first valve disc and the second valve disc, and in particular the third valve disc, and is connected to a drive device so that the valve discs can be adjusted together by the drive device. The coupling arrangement can be implemented, for example, using a shaft, a joint (such as a universal joint), a bearing, and / or a gear ratio.

[0034] For example, simultaneous adjustment of all coupled valve discs can be provided by a mechanical solution. In this way, a uniform and symmetrical fluid flow through the valve can be achieved by providing all openings with the same opening cross-section, in particular already when the valve part openings are first opened and the flow through all openings is and remains the same in terms of volumetric or mass flow rate.

[0035] According to another embodiment, the drive device comprises at least a first drive part and a second drive part, in particular a third drive part, in particular a respective motor, the first drive part being coupled to the first valve disc, the second drive part being coupled to the second valve disc, in particular the third drive part being coupled to the third valve disc.

[0036] In contrast to the previous embodiment, in this variant, each of the valve discs can be controlled and adjusted individually. This allows for greater flexibility in adjusting the flow behavior through the valve. For example, asymmetries in the volumetric flow caused by processing equipment in the process chamber can be corrected. Such corrections can be achieved by providing different opening cross sections for the individual valve part openings.

[0037] In particular, the flow behavior within the chamber can be adjusted to compensate for asymmetric flow caused, for example, by configurations within the chamber for processing the substrate (e.g., chuck, fixture, electrode, etc.). The flow will be correspondingly non-uniform through the process chamber when using conventional valves. By making the downstream flow adjustable using the valves of the present invention, the downstream flow of fluid can counteract the asymmetric flow through the chamber, ultimately resulting in an overall symmetric flow through the chamber. Thus, the flow through the valve can be correspondingly asymmetric (non-centric, i.e., asymmetric about a central axis).

[0038] For example, there may be different flow rates on different (eg, opposite) sides of the valve.

[0039] The regulating vacuum valve may in particular have a control device, in particular a regulating device, and the drive device (and its drive parts) may be controlled by control signals, in particular controlled variables, provided by the control device. In particular, each drive part of the drive device may be controlled individually by a (individual) control signal.

[0040] In one embodiment, the regulating vacuum valve may have a first port and a second port, the first valve seat and the second valve seat being arranged in a flow path interconnecting the first port and the second port and defining a flow path, and in particular the first valve disc and the second valve disc being arranged in the open position at least substantially, in particular completely, outside the flow path.

[0041] Two ports can be provided, particularly for the construction of a regulating vacuum valve between a process or vacuum chamber and a vacuum pump. By selectively setting or adjusting the opening state of the valve, a target pressure or pressure curve in the chamber can be set or adjusted by generating a vacuum on the side of the vacuum pump. The two ports thus define a flow path, which can be completely or partially blocked by a valve closure.

[0042] In one embodiment, the first and second valve portion openings, in particular the third valve portion opening, can be arranged symmetrically with respect to a central axis of the regulated vacuum valve, which central axis extends through the valve center point and in particular forms the central axis of the flow path. Due to its shape, the valve can define, on the one hand, a path for the fluid flow and, therefore, on the other hand, a restricted flow path for the fluid. The central axis is in particular located in the center of this flow path and extends along the length of the flow path.

[0043] At least one of the valve discs can be linearly adjustable along an adjustment axis. The valve closure can also be designed to be linearly adjustable. The contact surface (sealing surface) of the closure can be equidistant circumferentially from the corresponding sealing surface of the valve seat at any time during movement. A first sealing plane defined by the sealing surface can be (always) aligned parallel to a second sealing plane (contact plane) defined by the contact surface. The valve closure is moved parallel to the valve seat. Alternatively, the valve closure can be rotatably mounted.

[0044] In one embodiment, at least one of the valve discs may be in the form of a hinged valve closure rotatably mounted about an axis of rotation.

[0045] The drive and at least one of the valve discs are connected to the at least one valve disc, and the at least one valve disc is connected to the at least one valve disc. handleThe first and second sealing planes can be particularly designed to be adjustable to a fine-tuning position inclined in a defined manner so as to enclose a defined angle relative to the valve seat, and can interact with each other, in particular be coupled together; handle the sealing surface defines a first sealing plane; handle The contact surface defines a second sealing plane. handle It may be in full contact with one sealing or contacting surface and only partial contact with the other sealing or contacting surface.

[0046] Thus, in the fine adjustment position, a smaller percentage of the surface area of ​​the seal is in contact or compression with the opposing sealing surface than in the closed position.

[0047] The specific relative tilt position between the valve seat and the valve closure and the adjustable opening range of the valve opening as a function of the tilt allow advantageous pressure and flow regulation. Such regulation can typically be used, for example, when setting a target pressure using process gases and related requirements. The continuous laminar flow of medium through the opening, which can be achieved in this way, makes it possible to avoid pressure fluctuations and reach the target pressure more quickly. The fact that the possibility of completely separating the valve disc from the valve seat (open position) is still provided also means that the flow opening can be selected to be very large.

[0048] A larger opening angle means a larger flow opening and therefore the potential for a larger volumetric flow per unit time. Narrowing the opening angle allows for full contact between the valve seat and the sealing surface or seal of the valve disc, thereby gradually and / or continuously reducing the flow until the partial opening is fully closed (closed position).

[0049] With the valve according to the invention, the above flows can be advantageously regulated, i.e., even at very low pressures, while providing and maintaining a substantially symmetrical laminar flow.

[0050] In one embodiment, the drive device and at least one of the valve discs can be designed and coupled in such a way that when at least one of the valve discs is moved from an open position to a closed position or from a closed position to an open position, the at least one valve disc assumes a fine adjustment position before reaching the closed position or before reaching the open position, which can be achieved, for example, by a corresponding actuation or control of the drive device, for example, by controlled angular adjustment of the valve disc relative to the valve seat.

[0051] Regarding the orientation of the sealing surface of the valve seat, according to one embodiment, a first sealing surface (of the valve seat) faces in a direction parallel to the opening axis and can extend perpendicular to the opening axis.

[0052] According to one embodiment of the invention, at least one of the valve discs is positioned in the fine adjustment position such that a second sealing plane defined by the extension of its contact surface lies obliquely relative to the opening axis.

[0053] In one embodiment, the first and second sealing planes subtend a defined angle α in the open and fine-tuning positions, and the first and second sealing planes are aligned essentially parallel to one another in the closed position. During movement from the fine-tuning position to the closed position, the value of angle α thus continually approaches and eventually reaches "zero."

[0054] It should be understood that, according to one embodiment, not only one fine adjustment position can be set, but also a second fine adjustment position, several fine adjustment positions or several fine adjustment positions of the valve disc, in particular successively, in which case the angle α enclosed by the first and second sealing planes n are different in each case, and the first and second sealing surfaces are only partially in contact in each case by the sealing element (seal). Thus, the fine adjustment positions can each correspond to a different tilt position of the valve disc relative to the valve seat. In particular, each tilt position can be assigned to a respective fine adjustment position during the closing sequence.

[0055] In particular, the defined flow behavior through the regulating vacuum valve, in particular through at least two valve openings, can be adjustable and / or adjustable, in particular the flow behavior can be adjusted asymmetrically with respect to a central axis of the regulating vacuum valve, which central axis extends through the valve center point and in particular forms the central axis of the flow path. In this way, at least partial correction of the flow behavior that is initially asymmetric due to asymmetries in the chamber can be achieved.

[0056] In particular, the fine adjustment positions can be set individually or continuously in a controlled manner, thus providing a particularly continuous adjustment of the volumetric or mass flow rate of the medium through the valve opening. In particular, the flow can be maintained as a laminar flow. Such adjustment is provided in particular by a step motor or servo motor of the drive device for providing rotation of the valve disc.

[0057] According to one embodiment, the first valve seat and the second valve seat can be disposed in a common plane. Alternatively, the first valve seat and the second valve seat can be disposed at an angle relative to each other such that the plane defined by the first sealing surface and the plane defined by the second sealing surface subtend a defined angle. For example, the seats can be oriented such that the defined sealing planes each include a side of an imaginary pyramid.

[0058] In one embodiment, the alignment may be such that the opening axes defined by the respective valve openings in the valve seat intersect the centers of the respective valve part openings and extend perpendicular to the respective sealing planes defined by the extension of the respective sealing surfaces, the respective opening axes intersecting, in particular at a common intersection point, the common intersection point being in particular on the central axis of the valve.

[0059] According to one embodiment, the drive device comprises at least one motor and at least one guide element, in particular a guide rod, which can be moved along the longitudinal axis under the control of the at least one motor, and the valve disc is movable together with the guide element relative to the valve seat.

[0060] The position of the longitudinal axis is defined in particular by the extension of a guide part, for example designed or designated as a push rod or a guide rod, and / or by the direction of the linear movement provided by the drive device.

[0061] The device according to the invention will be explained in more detail below, purely by way of example, by means of specific exemplary embodiments shown diagrammatically in the drawings, in which further advantages of the invention will also be discussed. [Brief explanation of the drawings]

[0062] [Figure 1a] 1A and 1B are cross-sectional views of a first embodiment of a regulating vacuum valve according to the present invention in a closed position and an open position. [Figure 1b] 1A and 1B are cross-sectional views of a first embodiment of a regulating vacuum valve according to the present invention in a closed position and an open position. [Figure 2a] 1A and 1B are plan views of a first embodiment of a regulating vacuum valve according to the present invention in an open position and a closed position; [Figure 2b] 1A and 1B are plan views of a first embodiment of a regulating vacuum valve according to the present invention in an open position and a closed position; [Figure 3] FIG. 2 shows a second embodiment of a regulating vacuum valve according to the invention. [Figure 4a] 3A and 3B are cross-sectional views of a third embodiment of a regulating vacuum valve according to the present invention in the open and closed positions. [Figure 4b] 3A and 3B are cross-sectional views of a third embodiment of a regulating vacuum valve according to the present invention in the open and closed positions. [Figure 5a] 10A and 10B are plan views of a third embodiment of a regulating vacuum valve according to the present invention in the open and closed positions; [Figure 5b] 10A and 10B are plan views of a third embodiment of a regulating vacuum valve according to the present invention in the open and closed positions; [Figure 6] FIG. 10 is a perspective view showing a third embodiment of a regulating vacuum valve according to the present invention. [Figure 7] FIG. 2 shows another embodiment of a regulating vacuum valve according to the present invention connected to a process chamber. [Figure 8]1 illustrates another embodiment of a regulating vacuum valve according to the present invention connected to a process chamber having asymmetric chamber internals. DETAILED DESCRIPTION OF THE INVENTION

[0063] Figure 1a shows a schematic cross-sectional view of an embodiment of a regulating vacuum valve 10 according to the present invention in a closed position. Figure 2a shows a plan view of an embodiment of the regulating vacuum valve 10, also in a closed position. Figures 1b and 2b show an embodiment of the regulating vacuum valve 10 in the corresponding open position.

[0064] The regulator valve 10 has three valve sub-openings, only two of which, 11a and 11b, are shown in cross section. Figures 2a and 2b show all three sub-openings and handle The valve disc and seat arrangement is shown.

[0065] In the following, the first and second valve discs, the valve seat and handle The part is also referred to as representing the third valve portion opening, the design around which is essentially similar to the other two valve portion openings.

[0066] Valve portion openings 11a-11c are symmetrically arranged about a central axis Z of valve 10. Central axis Z is defined by the center of flow of valve 10. The center of flow corresponds to the geometric center of the flow path or flow passage for fluid provided by each valve portion opening together.

[0067] Thus, the regulating vacuum valve 10 has a first valve seat, a second valve seat, and a third valve seat. Here, each of the three valve seats has a valve portion opening 11a-11c, and the valve portion openings 11a-11c are surrounded by respective sealing surfaces 12a-12c. A first valve disc 13a, a second valve disc 13b, and a third valve disc 13c are provided corresponding to the valve seats. The valve discs 13a-13c are designed such that their contact surfaces 14a-14c (disc-side sealing surfaces) correspond to the sealing surfaces 12a-12c of the valve seats. Therefore, each of the contact surfaces has essentially the same shape and is respectively handle It has a spatial extent according to the sealing surface.

[0068] Each valve disc 13a-13c has a sealing means, in particular a seal, for example in the form of an O-ring or a vulcanized polymer, in particular a fluoropolymer, on its contact surface 14a-14c. By way of example, such a seal is shown on contact surface 14b in Figure 1b. According to an alternative embodiment, a sealing means can alternatively or additionally be provided on the side of the sealing surfaces 12a-12c.

[0069] According to the number of valve discs, a corresponding number of drive elements 15a-15c are provided in this embodiment, which together form the drive device of the valve 10. Each drive element 15a-15c is connected to a valve disc 13a-13c by a connecting rod.

[0070] The drive elements 15a-15c are designed to provide linear adjustability of the valve discs 13a-13c along the respective axes defined by the extension of the connecting rods. The drives are designed, for example, as linear motors or stepper motors. The alignment of the valve discs 13a-13c or contact surfaces 14a-14c is parallel to the alignment of the valve seats or sealing surfaces 12a-12c in both the open and closed states.

[0071] In the illustrated embodiment, a motor 15a-15c is associated with each valve disc 13a-13c. In an alternative embodiment (not shown here), there can be only one motor connected to all valve discs by a coupling device. The coupling device can include, for example, joints, shafts, and / or gear ratios. Thus, opening or closing of the valve can be achieved by simultaneously opening or closing all valve portion openings.

[0072] The three valve seats are disposed at an angle to one another. Each sealing surface 12a-12c defines a sealing plane by its shape and extension.

[0073] In particular, the valve seats are arranged so that each sealing plane surrounds a different side of an imaginary, in particular regular or rectilinear, polygonal-based pyramid. In other words, each side of the imaginary polygonal-based pyramid lies in one of the sealing planes. In the illustrated embodiment, the base area of ​​the pyramid is triangular.

[0074] Such a configuration of the individual valve portion openings 11a-11c offers the advantage that the mechanism for providing the open and closed states is simpler. In addition to opening and closing the openings 11a-11c, the linear adjustment of the disks 13a-13c, which can be precisely controlled by the drive, also allows the setting of a specific opening cross-section for both each individual valve portion opening 11a-11c and the resulting overall valve opening.

[0075] For example, the valve disc handle By gradually approaching the valve seat, the opening cross section of the associated valve part opening can be reduced in stages, in particular continuously.

[0076] Thus, the regulating vacuum valve 10 also offers the possibility of selectively adjusting the fluid flow through the valve opening(s). If a specific internal pressure is to be provided in the process chamber, then preferably, the regulating vacuum valve 10, connected to the vacuum pump on the one hand and the process chamber on the other hand, can be used to set a specific amount (mass or volume) of fluid flowing out per unit time. For example, the internal pressure in the chamber determined by a pressure sensor can be used as the controlled variable. Alternatively, the opening cross section can be set and changed in a controlled manner using predetermined rules.

[0077] The regulating vacuum valve 10 further includes a first port 16 and a second port 17. At least one of the ports may be formed as a flange. A valve seat is disposed in the flow path of the flow chamber connecting the first port 16 and the second port 17.

[0078] It should be noted that the present invention does not only extend to embodiments with three or more valve part openings, valve seats and valve discs, but also in particular to solutions with two valve openings, valve seats and valve discs each.

[0079] Another embodiment of the present invention is shown in Figure 3. Regulating vacuum valve 20 also has three valve seats and three corresponding valve discs 23a-23c provided for regulating the flow rate through respective valve portion openings 21a-21c.

[0080] A first port 26 opposite the second port provides connection of the valve 20 to, among other things, a pipeline, a process chamber, or a vacuum pump.

[0081] Each valve disc 23a-23c is mechanically coupled to a respective drive element 25a-25c and can thus be adjusted along a respective linear adjustment axis. The functional principle, i.e., opening, blocking and adjusting the flow, is therefore similar to that of the previous embodiment.

[0082] Each of the valve discs 23a to 23c has a handle Together with the drive components 25a-25c, they form a valve assembly. Each valve assembly thus has exactly one drive component and one valve disc, in addition to further fixed and sealing components. Valve assembly 28, consisting of valve closure 23c and motor 25c, is referenced by way of example in FIG. 3. Two further similar such assemblies are formed by the combination of valve closure 23a with motor 25a and the combination of valve closure 23b with motor 25b.

[0083] As shown in Figure 3, the regulating vacuum valve 20 is designed so that the valve assembly is modular and replaceable. The housing 29 of the valve 20 includes three valve seats and therefore has three circumferential recesses. Each recess is associated with one of the valve seats and is located opposite that seat.

[0084] The recess and the valve assembly 28 are adapted to one another so that the assembly 28 can be inserted into the recess and connected by its fixing means. Such fixing can be achieved, for example, by a screw connection or by clamping. Preferably, a seal is provided between a contact surface running around the recess and a corresponding contact surface of the valve assembly 28.

[0085] The modular design allows for relatively easy replacement of defective or worn parts. For example, the sealing elements located on the sides of the valve discs 23a-23c are exposed to material stress with each adjustment in and out of the closed position and therefore must be replaced or renewed periodically. The advantageous modular design allows for significant time savings in this maintenance activity compared to conventional valve solutions.

[0086] Figures 4a, 4b and 5a, 5b show cross-sectional and plan views of a third embodiment of a regulating vacuum valve 30 according to the present invention. Figures 4a and 5a show the valve 30 in the open position, and Figures 4b and 5b show the valve 30 in the closed position.

[0087] This embodiment again includes three valve seats with respective circumferential sealing surfaces 32a-32c and respective valve portion openings 31a-31c. The valve seats or sealing surfaces 32a-32c are now arranged in a common plane. The valve portion openings 31a-31c each have the same shape and dimensions, but are each rotated 120° relative to the adjacent openings.

[0088] The regulating vacuum valve 30 also has three valve closures 33a-33c (valve discs) with contact surfaces 34a-34c, the sealing elements of which sealingly interact with the sealing surfaces 32a-32c of the valve seats in the closed position.

[0089] Each of the valve closures 33a-33c is mounted to rotate about a respective axis of rotation. In addition, each of the valve closures 33a-33c is coupled to a respective drive element 35a-35c (motor). By means of the motors 35a-35c, the valve discs 33a-33c can be rotated about their respective axes of rotation in a controlled manner. The valve discs 33a-33c thus act as flaps. The surface defined by the closing side of each flap and the sealing plane defined by the extension of each sealing surface enclose a variable opening angle α in this case, and the opening cross section of each of the valve part openings correlates to the opening angle α.

[0090] Each of the motors 35a-35c is individually controllable. The regulating vacuum valve 30 also has a control or regulating device that interacts with the motors and is designed to allow the motors to be controlled individually, as the case may be, or to allow the adjustment of the flaps 33a-33c to be performed synchronously by corresponding controls. For this purpose, the control or regulating device has corresponding algorithms and functions. The flaps 33a-33c can thus be moved simultaneously and synchronously, for example, so as to simultaneously provide the closed position when the flaps 33a-33c are moved to this closed position.

[0091] One advantage of the rotatable bearings of the valve closures 33a-33c is that they provide high-precision fine adjustment. In contrast to linear valve disc movement, the folding of the closures 33a-33c allows for very fine adjustment of the valve opening state, especially at very low pressures, by very small opening change steps, which are provided by the increasing flap-to-seat distance with increasing distance from the axis of rotation (for a given opening angle α>0).

[0092] The common problem with prior art valves, which can snap shut at very small opening angles, is avoided with the proposed solution by providing multiple valve discs and resulting in a lower operating force per valve disc.

[0093] The regulating vacuum valve 30 further includes a first port 36 and a second port 37. At least one of the ports may be formed as a flange. A valve seat is disposed in the flow path of the flow chamber connecting the first port 36 and the second port 37.

[0094] Figure 6 shows a perspective view of the regulating vacuum valve 30 according to Figures 4 and 5. The valve seat is designed so that the valve section openings 31a-31c defined by the valve seat define respective opening axes 39a-39c aligned parallel to one another. The opening axes 39a-39c intersect the centers of the respective valve section openings 31a-31c and extend perpendicular to the sealing planes defined by the sealing surfaces 32a-32c.

[0095] Dividing the overall valve opening into multiple partial openings also provides the advantage that multiple valve closures can be provided, thereby individually reducing the mass of each closure. Because there is less mass to be moved, significantly shorter adjustment times can be achieved, i.e., the time required to move one or all of the valve closures from an open position to a closed position (or vice versa) can be reduced.

[0096] FIG. 7 shows a process chamber 40 having a gas inlet 41 and a substrate 1 placed in the process chamber 40 to be processed.

[0097] On the side of the process chamber 40 opposite the gas inlet 41, a regulating vacuum valve 50 according to the present invention is provided according to another embodiment, connected to the gas outlet, and having two valve section openings 51 a, 51 b. Each valve opening is provided by a respective valve seat of the vacuum valve 50. A valve closure 53 a, 53 b is associated with each valve section opening 51 a, 51 b. The two valve closures 53 a, 53 b of the valve 50 are each designed to move on a hinge around a respective axis of rotation. By adjusting the flaps 53 a and 53 b, the opening angle and thus the hourly flow rate can be changed and set.

[0098] The flow of fluid through the process chamber is indicated by arrows. The specific design of the regulating vacuum valve 50 with multiple valve sub-openings 51 a and 51 b provides for symmetrical flow of fluid through the valve 50. Furthermore, by providing a general opening formed by the multiple sub-openings that is symmetrically configured about the central valve axis Z, the outflow of fluid from the process chamber 40 can also be performed symmetrically (concentrically).

[0099] For processing, the substrate 1 is preferably placed on a chuck that allows electrostatic holding of the substrate 1. The flow of process gases can also be directed concentrically (uniformly) around the chuck by symmetrical valve openings.

[0100] Such symmetric, uniform or concentric flow behavior is highly advantageous for processing substrates under vacuum or low pressure conditions, as it results in such a uniform distribution of process gas across the substrate, that for example, deposition or etching processes can be performed very uniformly, with high quality and reliability.

[0101] FIG. 8 shows an embodiment of a process chamber 40 having a gas inlet 41 and processing equipment 45 disposed within the process chamber 40 for substrates to be processed.

[0102] On the side of the process chamber 40 opposite the gas inlet 41 is a regulating vacuum valve 50 according to the present invention, also connected to the gas outlet and having two valve portion openings 51 a, 51 b. Each valve opening is provided by a respective valve seat of the vacuum valve 50. A valve closure 53 a, 53 b is associated with each valve portion opening 51 a, 51 b. The two valve closures 53 a, 53 b of the valve 50 are each designed to hinge about a respective axis of rotation. By adjusting the flaps 53 a and 53 b, the respective opening angles, and therefore the respective time flow rates, can be changed and set individually for each valve portion opening 51 a, 51 b.

[0103] The processing equipment 45 is asymmetrically positioned within the process chamber 40. Such a configuration of the processing equipment 45 is common when providing typical vacuum process performance. For example, the processing equipment 45 is mounted on only one side of the chamber 40. Thus, the processing equipment 45 is not centrally located within the chamber 40, and this placement or mounting alone causes asymmetric flow of fluid through the chamber 40. As a result, the fluid flows unevenly around the processing equipment 45.

[0104] Such asymmetric fluid flow through the chamber 40 can be corrected by the regulating vacuum valve 50 according to the present invention. By providing different opening states of the individual valve section openings 51a, 51b, the asymmetry in gas flow can be corrected. For this purpose, the valve closures 53a, 53b are set to different inclined positions (opening angles), thereby providing different opening cross sections in each case. The fluid outflow then no longer occurs centrally through the valve, but also asymmetrically within the valve relative to the central axis.

[0105] The different opening states allow the fluid flow to be set to different degrees across the chamber cross section, i.e. the gas flow behavior to different degrees in different regions of the chamber, e.g. different flow velocities at opposing chamber walls.

[0106] Such variable adjustment of fluid flow through the valve can correct for uneven, choppy flow behavior caused by the treatment device 45 so that the resulting flow around the treatment device 45 is symmetrical (uniform).

[0107] It should be understood that the figures shown are only schematic representations of possible exemplary implementations. According to the present invention, the various techniques can also be combined with each other and with prior art methods and devices for adjusting the volumetric flow rate or pressure of a process volume under vacuum conditions.

Claims

1. A regulating vacuum valve (10, 20, 30, 50) for regulating the volumetric or mass flow rate and blocking the flow path in an airtight manner, comprising: a first valve seat having a first valve opening (11a, 21a, 31a, 51a) defining a first opening axis (39a) and a first sealing surface (12a, 32a) surrounding said first valve opening (11a, 21a, 31a, 51a); a first valve disc (13a, 23a, 33a, 53a) having a first contact surface (14a, 34a) corresponding to said first sealing surface (12a, 32a); A drive unit comprising at least an open position in which the first valve disc (13a, 23a, 33a, 53a) and the first valve seat are in a non-contacting relationship with respect to one another; a closed position in which there is axially sealing contact between the first sealing surface (12a, 32a) and the first contact surface (14a, 34a) via an intermediate sealing element, and the first valve opening (11a, 21a, 31a, 51a) is thereby closed in an airtight manner; the drive unit is designed to be adjustable in the forward and backward directions and is coupled to the first valve disc (13a, 23a, 33a, 53a); The regulating vacuum valve (10, 20, 30, 50) includes The regulating vacuum valve (10, 20, 30, 50) comprises at least a second valve seat having a second valve opening (11b, 21b, 31b, 51b) defining a second opening axis (39b) and a second sealing surface (12b, 32b) surrounding said second valve opening (11b, 21b, 31b, 51b); a second valve disc (13b, 23b, 33b, 53b) having a second contact surface (14b, 34b) corresponding to said second sealing surface (12b, 32b); Including, the entire valve opening of the regulating vacuum valve is formed by at least the first valve opening (11a, 21a, 31a, 51a) and the second valve opening (11b, 21b, 31b, 51b); At least one of the valve discs is designed as a flap valve closure rotatably mounted around a rotation axis. A regulating vacuum valve (10, 20, 30, 50).

2. The regulating vacuum valve (10, 20, 30, 50) a third valve seat having a third valve opening (11c, 21c, 31c) defining a third opening axis (39c) and a third sealing surface (12c, 32c) surrounding said third valve opening (11c, 21c, 31c); a third valve disc (13c, 23c, 33c) having a third contact surface (14c, 34c) corresponding to said third sealing surface (12c, 32c); Including, The overall valve opening is further formed by the third valve opening (11c, 21c, 31c). A regulated vacuum valve (10, 20, 30, 50) according to claim 1, characterized in that

3. The drive unit drives the coupled valve disc to the second valve disc (13b, 23b, 33b, 53b) at least: a respective open position, in which the respective valve disc and the respective valve seat are in a non-contacting position relative to one another; a closed position, in which there is axially sealing contact between the respective sealing surface and the respective contact surface via a respective intermediate sealing element, and the respective valve opening is thereby closed in an airtight manner; The back and forth direction can be adjusted. A regulated vacuum valve (10, 20, 30, 50) according to claim 1 or 2, characterized in that

4. 4. The regulating vacuum valve (10, 20, 30, 50) according to any one of claims 1 to 3, characterized in that the regulating vacuum valve (10, 20, 30, 50) includes a coupling arrangement, the coupling arrangement providing a mechanical coupling between the first valve disc (13a, 23a, 33a, 53a) and the second valve disc (13b, 23b, 33b, 53b) and connected to the drive device such that the respective valve discs can be adjusted together by the drive device.

5. the drive device comprises at least a first drive part (15a, 25a, 35a) and a second drive part (15b, 25b, 35b), the first drive component (15a, 25a, 35a) is coupled to the first valve disc (13a, 23a, 33a, 53a) and the second drive component (15b, 25b, 35b) is coupled to the second valve disc (13b, 23b, 33b, 53b); A regulating vacuum valve (10, 20, 30, 50) according to any one of claims 1 to 4, characterized in that

6. The regulating vacuum valve (10, 20, 30, 50) according to any one of claims 1 to 5, characterized in that the regulating vacuum valve (10, 20, 30, 50) has a control device, and the drive device can be controlled based on a control signal provided by the control device.

7. 7. A regulated vacuum valve (10, 20, 30, 50) according to claim 6, characterized in that each driving component of the driving device is individually controllable by the control signal.

8. 8. The regulating vacuum valve (10, 20, 30, 50) according to any one of claims 1 to 7, characterized in that the regulating vacuum valve (10, 20, 30, 50) has a first port (16, 26, 36) and a second port (17, 27, 37), and the first valve seat and the second valve seat are arranged in a flow path connecting the first port (16, 26, 36) and the second port (17, 27, 37) to each other.

9. the drive device and the at least one of the valve discs are designed and cooperated to move the at least one of the valve discs to a fine adjustment position; the at least one of the valve discs is inclined relative to a corresponding valve seat such that a first sealing plane and a second sealing plane are defined that subtend a defined angle α, a corresponding sealing surface defining the first sealing plane and a corresponding contact surface defining the second sealing plane; The sealing element is in full contact with the corresponding sealing or contact surface and only partially contacts the other sealing or contact surface. A regulated vacuum valve (10, 20, 30, 50) according to claim 1, characterized in that

10. 10. The regulated vacuum valve (10, 20, 30, 50) according to claim 9, characterized in that the drive device and the at least one of the valve discs are designed and coupled such that when the at least one of the valve discs is moved from the open position to the closed position or from the closed position to the open position, the at least one valve disc assumes the fine adjustment position before reaching the closed position or the open position.

11. the first sealing surface (12a, 32a) faces in a direction parallel to the first opening axis (39a) and extends perpendicular to the first opening axis (39a); the at least one of the valve discs is positioned in the fine adjustment position such that the second sealing plane defined by the extension of the contact surface is oblique to the first opening axis (39a); the first sealing plane and the second sealing plane subtend a respective defined angle α>0° in the open position and in the fine adjustment position; the first sealing plane and the second sealing plane are aligned essentially parallel in the closed position; A regulating vacuum valve (10, 20, 30, 50) according to claim 9 or 10, characterized in that

12. the at least one second fine-tuning position, several fine-tuning positions or a plurality of fine-tuning positions of the valve disc are adjustable; the angle α enclosed by the first sealing plane and the second sealing plane, respectively; ｎ But it varies each time, The regulating vacuum valve (10, 20, 30, 50) according to claim 11, characterized in that the sealing element is in full contact with the corresponding sealing or contact surface in each case and only partially in contact with the other sealing or contact surface.

13. 13. The regulating vacuum valve (10, 20, 30, 50) according to claim 12, characterized in that the fine adjustment positions can be adjusted individually or continuously in a controlled manner, thereby providing control of the volumetric or mass flow rate of a medium through the valve opening.

14. A regulating vacuum valve (10, 20, 30, 50) according to any one of claims 1 to 13, characterized in that at least one of the valve discs is linearly adjustable along an adjustment axis.

15. 13. The regulated vacuum valve (10, 20, 30, 50) according to claim 12, characterized in that the first valve opening (11a, 21a, 31a, 51a) and the second valve opening (11b, 21b, 31b, 51b) are arranged symmetrically with respect to a central axis (Z) of the regulated vacuum valve (10, 20, 30, 50), the central axis (Z) extending through a valve center point.

16. the first valve seat and the second valve seat are arranged in a common plane, or the first valve seat and the second valve seat are arranged at an angle relative to one another such that a plane defined by the first sealing surface and a plane defined by the second sealing surface subtend a defined angle β; A regulating vacuum valve (10, 20, 30, 50) according to any one of claims 1 to 15, characterized in that

17. the respective opening axes defined by the respective valve openings in the valve seat intersect the center points of the respective valve openings and extend perpendicular to the respective sealing planes defined by the extensions of the respective sealing surfaces; The axes of the openings intersect Regulating vacuum valve (10, 20, 30, 50) according to claim 15, characterized in that

18. The first valve disc and the second valve disc are outside the flow path in the open position. A regulated vacuum valve (10, 20, 30, 50) according to claim 8, characterized in that

19. A defined flow behavior through said regulating vacuum valve (10, 20, 30, 50) can be set and / or adjusted A regulated vacuum valve (10, 20, 30, 50) according to claim 12, characterized in that

20. The flow behavior can be set asymmetrically with respect to a central axis (Z) of the regulating vacuum valve (10, 20, 30, 50), the central axis (Z) extending through the valve center point. Regulated vacuum valve (10, 20, 30, 50) according to claim 19, characterized in that

21. a first valve seat having a first valve opening (11a, 21a, 31a, 51a) defining a first opening axis (39a) and a first sealing surface (12a, 32a) surrounding said first valve opening (11a, 21a, 31a, 51a); a first valve disc (13a, 23a, 33a, 53a) having a first contact surface (14a, 34a) corresponding to said first sealing surface (12a, 32a); ·at least, an open position in which the first valve disc (13a, 23a, 33a, 53a) and the first valve seat are in a non-contacting relationship with respect to one another; a closed position in which there is axially sealing contact between the first sealing surface (12a, 32a) and the first contact surface (14a, 34a) via an intermediate sealing element and the first valve opening (11a, 21a, 31a, 51a) is thereby closed in an airtight manner; a drive unit coupled to the first valve disc (13a, 23a, 33a, 53a) designed to be adjustable in the forward and backward directions; A regulating vacuum valve (10, 20, 30, 50) for regulating a volumetric or mass flow rate and blocking a flow path in an airtight manner, comprising: The regulating vacuum valve (10, 20, 30, 50) comprises at least a second valve seat having a second valve opening (11b, 21b, 31b, 51b) defining a second opening axis (39b) and a second sealing surface (12b, 32b) surrounding said second valve opening (11b, 21b, 31b, 51b); a second valve disc (13b, 23b, 33b, 53b) having a second contact surface (14b, 34b) corresponding to said second sealing surface (12b, 32b); Including, the entire valve opening of the regulating vacuum valve is formed by at least the first valve opening (11a, 21a, 31a, 51a) and the second valve opening (11b, 21b, 31b, 51b); The first valve seat and the second valve seat are inclined and oriented relative to each other to include each side of a pyramid. A regulating vacuum valve (10, 20, 30, 50).

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