VACUUM VALVE FOR PROVIDING A SYMMETRICAL FLUID FLOW

Abstract

Disclosed is a regulating vacuum having a first valve seat having a first valve opening defining a first opening axis and a first sealing surface surrounding the first valve opening, and a first valve disk having a first contact surface corresponding to the first sealing surface. The valve includes a drive unit coupled to the first valve disk to adjust at least between an open position to a closed position. The regulating vacuum valve has at least one second valve seat, having a second valve opening with a second sealing surface. In addition, a second valve disk having a second contact surface corresponding to the second sealing surface is provided. An overall valve opening of the regulating vacuum valve is formed by the first valve opening as a first valve partial opening and the second valve opening as a second valve partial opening.

Claims

1. A regulating vacuum valve for regulating a volumetric or mass flow and for interrupting a flow path in a gas-tight manner, comprising a first valve seat having a first valve opening defining a first opening axis and a first sealing surface surrounding the first valve opening first valve disk having a first contact surface corresponding to the first sealing surface, a drive unit which is designed and coupled to the first valve disk in such a way that it can be adjusted at least from an open position in which the first valve disk and the first valve seat are in contactless relationship relative to each other, to a closing position in which an axially sealing contact exists between the first sealing surface and the first contact surface via an intermediate sealing element, and the first valve opening is thereby closed in a gas-light manner, and back again, wherein the regulating vacuum valve at least comprises a second valve seat having a second valve opening defining a second opening axis and a second sealing surface surrounding the second valve opening, a second valve disk having a second contact surface corresponding to the second sealing surface, wherein all overall valve opening of the regulating vacuum valve is formed by at least the first valve opening as a first valve partial opening and the second valve opening as a second valve partial opening.

2. The regulating vacuum valve according to claim 1, wherein the regulating vacuum comprises a third valve seat having a third valve opening defining a third opening axis and a third sealing surface surrounding the third valve opening and a third valve disk having a third contact surface corresponding to the third sealing surface, wherein the overall valve opening is additionally formed by the third valve opening as the third valve partial opening.

3. The regulating vacuum valve according to claim 1, wherein the drive unit is coupled to the second valve disk, in particular to the third valve disk, in such a manner that the coupled valve disks can be adjusted at least from a respective open position, in which the respective valve disk and the respective valve seat are in contactless position relative to each other, to a closing position, in which an axially sealing, contact exists between the respective sealing surface and the respective contact surface via a respective intermediate sealing element and the respective valve partial opening is thereby closed in a gas-tight manner, and back again.

4. The regulating vacuum valve according to claim 1, wherein the regulating vacuum valve comprises a coupling arrangement, which coupling arrangement provides a mechanical coupling of the first valve disk with the second valve disk, and in particular with the third valve disk and is connected to the drive unit in such a way that the respective valve disks can be adjusted together by means of the drive unit.

5. The regulating vacuum valve according to claim 1, wherein the drive unit has at least a first and a second, in particular a third, drive component, in particular respective motors, and the first drive component is coupled to the first valve disk and the second drive component coupled to the second valve disk, in particular the third drive component is coupled to the third valve disk.

6. The regulating vacuum valve according to claim 1, wherein the regulating vacuum valve has a control unit, in particular a regulating unit, and the drive unit can be controlled on the basis of a control signal provided by the control unit, in particular on the basis of a controlled variable.

7. The regulating vacuum valve according to claim 1, wherein each drive component of the drive unit is individually controllable by means of the control signal.

8. The regulating vacuum valve according to claim 1, wherein the regulating vacuum valve has a first port and a second port, wherein the first and second valve seats are arranged in a flow channel which connects the first port and the second port to one another, in particular wherein the first and the second valve disk are present in the open position at least substantially in particular completely, outside the flow channel.

9. The regulating vacuum valve according to claim 1, wherein at least one of the valve disks is designed as a flap valve closure rotatably mounted about an axis of rotation.

10. The regulating vacuum valve according to claim 9, wherein the drive unit and the at least one of the valve disks are designed and cooperate, in particular are coupled, in such a way that the at least one of the valve disks can be moved into a fine regulating position, wherein the at least one of the valve disks is inclined relative to the associated valve seat in a defined manner such that a first sealing plane and a second sealing plane enclose a defined angle x, wherein the associated sealing surface defines the first sealing plane and the associated contact surface defines the second sealing plane, and the sealing element is in full contact with the associated sealing surface or contact surface and only partially in contact with the other sealing surface or contact surface.

11. The regulating vacuum valve according to claim 9, wherein the drive unit and the at least one of the valve disks are designed and coupled in such a way that, when the at least one of the valve disks is moved from the open position to the closed position or from the closed position to the open position, the at least one valve disk assumes the fine regulating position before reaching the closed position or before reaching, the open position.

12. The regulating vacuum valve according to claim 9, wherein the first sealing surface faces in a direction parallel to the opening axis and extends orthogonally to the opening axis, and the at least one of the valve disks is positioned in the fine regulating position such that the second sealing plane defined by an extension of the contact surface is oblique to the opening axis, wherein the first and the second sealing planes enclose a respective defined angle x>0° in the open position and in the fine regulating position, and the first and second sealing planes are aligned essentially parallel in the closed position.

13. The regulating vacuum valve according to claim 12, wherein a second, several or a plurality of fine regulating positions of the at least one of the valve disks are adjustable, in particular continuously, wherein the angle x.sub.n respectively enclosed by the first and second sealing planes is different in each case, and the sealing element is in full contact in each case with the associated sealing surface or contact surface and in only partial contact with the other sealing surface or contact surface; in particular wherein a defined flow behavior through the regulating vacuum valve, in particular through the at least two valve openings in their entirety, can be set and/or regulated, in particular wherein the flow behavior can be set asymmetrically with respect to a central axis (Z) of the regulating vacuum valve wherein the central axis (Z) extends through a valve center point, in particular forms a central axis of the flow channel.

14. The regulating vacuum valve according to claim 13, wherein the fine regulating positions can each be adjusted individually or continuously in a controlled manner and thus an in particular continuous control of the volumetric or mass flow of a medium through the valve partial opening, can be provided.

15. The regulating vacuum valve according to claim 1, wherein at least one of the valve disks is linearly adjustable along an adjustment axis.

16. The regulating vacuum valve according to claim 1, wherein the first and the second valve partial openings, in particular the third valve partial opening, are an arranged symmetrically about a central axis (Z) of the regulating vacuum valve, wherein the central axis (Z) extends through a valve center point, in particular forming a central axis of the flow channel.

17. The regulating vacuum valve according to claim 1, wherein 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 inclined relative to each other such that a plane defined by the first sealing surface and a plane defined by the second sealing surface enclose a defined angle β.

18. The regulating vacuum valve according to claim 1, wherein the opening axis defined by the respective valve opening of a valve seat intersects the center point of the respective valve partial opening and extends orthogonally to the respective sealing plane defined by the extension of the respective sealing surface, and the respective opening axes intersect, in particular they intersect at a common point of intersection.

Description

[0061] The device according to the invention is described in more detail below by means of specific exemplary embodiments shown schematically in the drawings, purely by way of example, wherein further advantages of the invention are also discussed. The figures show detail:

[0062] FIGS. 1a-b show a first embodiment of a regulating vacuum valve according to the invention in a closed position and in an open position in cross-section;

[0063] FIGS. 2a-b show the first embodiment of a regulating vacuum valve according to the invention in an open position and in a closed position in a plan view;

[0064] FIG. 3 shows a second embodiment of a regulating vacuum valve according to the invention;

[0065] FIGS. 4a-b show a third embodiment of a regulating vacuum valve according to the invention in an open position and in a closed position in cross-section;

[0066] FIGS. 5a-b show the third embodiment of a regulating vacuum valve according to the invention in an open position and in a closed position in a plan view;

[0067] FIG. 6 shows the third embodiment of a regulating vacuum valve according to the invention in perspective;

[0068] FIG. 7 shows a further embodiment of a regulating vacuum valve according to the invention connected to a process chamber; and

[0069] FIG. 8 shows a further embodiment of a regulating vacuum valve according to the invention connected to a process chamber with asymmetrical chamber interior structure.

[0070] FIG. 1a shows a schematic cross-section of an embodiment of a regulating vacuum valve 10 according to the invention in a closed position. FIG. 2a shows the embodiment of the regulating vacuum valve 10 in a plan view, also in the closed position. FIGS. 1b and 2b show the embodiment of the regulating vacuum valve 10 correspondingly in the open position.

[0071] The regulating valve 10 has three valve partial openings, wherein only two of the three openings 11a, 11b are shown in the cross-sectional illustration. The arrangement of all three partial openings as well as associated valve disks and valve seats can be seen in FIGS. 2a and 2b.

[0072] In the following, reference will also be made in part to a first and second valve disk, valve seat and associated components as representative of the third valve partial opening. The design around the third valve partial opening is essentially analogous to the other two.

[0073] The valve partial openings 11a-11c are arranged symmetrically about a central axis Z of the valve 10. The central axis Z is defined by a flow center of the valve 10. The flow center in turn corresponds to a geometric center of a flow path or flow channel for a fluid provided jointly by the valve partial openings.

[0074] Accordingly, the regulating vacuum valve 10 has a first, a second and a third valve seat. Each of the three valve seats in turn has a valve partial opening 11a-11c, which are surrounded by respective sealing surfaces 12a-12c. Corresponding to the valve seats, a first valve disk 13a, a second valve disk 13b and a third valve disk 13c are provided. The valve disks 13a-13c are designed in such a way that their contact surfaces 14a-14c (disk-side sealing surfaces) correspond to the sealing surfaces 12a-12c of the valve seats. Accordingly, the contact surfaces each have essentially the same shape and spatial extent according to the respectively associated sealing surfaces.

[0075] Each valve disk 13a-13c has a sealing means, in particular a seal, e.g. in the form of an O-ring or vulcanized polymer, in particular fluoropolymer, on its contact surface 14a-14c. As an example, such a seal can be seen on contact surface 14b in FIG. 1b. According to alternative embodiments, the sealing means can be provided alternatively or additionally on the side of the sealing surfaces 12a-12c.

[0076] According to the number of valve disks a corresponding number of drive components 15a-15c are provided according to this embodiment, which together form the drive unit of the valve 10. Each drive component 15a-15c, is connected to a valve disk 13a-13c by means of a coupling rod.

[0077] The drive components 15a-15c are designed in such a way that linear adjustability of the valve disks 13a-13c is provided along respective axes defined by the extension of the coupling rods. The drives are designed, for example, as linear motors or stepper motors. The alignment of the valve, disks 13a-13c or the contact surfaces 14a-14c is parallel to the alignment of the valve seats or the sealing surfaces 12a-12c both in the open and in the closed state.

[0078] In the embodiment shown, a motor 15a-15c is associated with each valve disk 13a-13c. In an alternative embodiment (not shown here), only one motor can be provided, which is connected to all valve disks by means of a coupling unit. The coupling unit may comprise, for example, joints, shafts and/or gear ratios, etc. An opening or dosing of the valve can thus be effected by a simultaneous opening or closing of all valve partial openings.

[0079] The three valve seats are arranged at an angle relative to each other. Each sealing surface 12a-12c defines a sealing pane by its shape and extension.

[0080] In particular the valve seats are aligned in such a way that the respective sealing planes enclose different side faces of a virtual, in particular regular or straight, pyramid with a polygonal base. In other words, each side face of the virtual pyramid with polygonal base lies in one of the sealing planes. In the embodiment shown, the base area of the pyramid is triangular.

[0081] Such an arrangement of the individual valve partial openings 11a-11c offers the advantage of a less complex mechanism for providing the open and closed state. A linear adjustment of the disks 13a-13c, which can be precisely controlled by means of the drive unit, in addition to the opening and closing of the openings 11a-11c, also enables the setting of a specific opening cross-section of both each individual valve partial opening 11a-11c and a resulting overall valve opening.

[0082] For example, by allowing a valve disk to gradually approach the associated valve seat, the opening cross-section of the relevant valve partial opening can be reduced step by step, in particular continuously.

[0083] Thus, the regulating vacuum valve 10 also provides the possibility to selectively adjust a fluid flow through the valve opening(s). If a certain internal pressure is to be provided in a process chamber, the regulating vacuum valve 10, which is then preferably connected to a vacuum pump on the one hand and to the process chamber on the other, can be used to set a certain quantity (mass or volume) of fluid that flows out per unit of time. For example., an internal pressure in the chamber determined by means of a pressure sensor can be used as a controlled variable. Alternatively, the opening cross-section can be set and varied in a controlled manner using a predetermined rule.

[0084] The regulating vacuum valve 10 further comprises a first port 16 and a second port 17. At least one of the ports may be formed as a flange. The valve seats are disposed in the flow path of a flow chamber connecting the first port 16 and the second port 17.

[0085] It should be noted that the invention does not extend solely to embodiments with three or more valve partial openings, valve seats and valve disks but in particular also includes those solutions which each have two valve openings, valve seats and valve disks.

[0086] FIG. 3 shows another embodiment of the invention. The regulating vacuum valve 20 also has three valve seats and three corresponding valve disks 23a-23c, which are provided for adjusting a flow rate through the respective valve partial openings 21a-21c.

[0087] A first port 26 opposite the second port provides connectivity of the valve 20 to, in particular, a pipeline, a process chamber, or a vacuum pump.

[0088] Each valve disk 23a-23c is mechanically coupled to a respective drive component 25a-25c and can thus be adjusted along a respective linear adjustment axis. The functional principle—opening, interrupting and regulating a flow—is thus similar to that of the preceding embodiment.

[0089] Each valve disk 23a 23c forms a valve assembly, with its respective associated drive component 25a-25c. Each valve assembly thus has—in addition to further fastening and sealing components—exactly one drive component and one valve disk. A valve assembly 28 consisting of valve closure 23c and motor 25c is referenced by way of example in FIG. 3. Analogous further two such assemblies are formed by the combination of the valve closure 23a with the motor 25a and by the combination of the valve closure 23b with the motor 25b.

[0090] As shown in FIG. 3, the regulating vacuum valve 20 is designed such that the valve assemblies are modularly interchangeable. The housing 29 of the valve 20, which housing 29 comprises the three valve seats, has three recesses circumferentially for this purpose. Each of the recesses is associated with one of the valve seats and, in particular, is arranged opposite this valve seat.

[0091] The recess and the valve assembly 28 are formed to be adapted to each other such that the as 28 is in into and connectable to the recess by means of the fastening means thereof. Such a fastening can take place, for example, by means of a screw connection or clamping. Preferably, a seal is provided between a contact surface running around the recess and the corresponding contact surface of the valve assembly 28.

[0092] The modular design allows comparatively simple replacement of defective or worn components. For example, the sealing elements arranged on the side of the valve disks 23a-23c are exposed to material stresses with each adjustment into or out of the closed position and must therefore be replaced or renewed in regular cycles. Due to the advantageous modular design, significant time savings can be realized for this maintenance activity compared to conventional valve solutions.

[0093] FIGS. 4a, 4b and 5a, 5b show a third embodiment of a regulating vacuum valve 30 according to the invention in cross-section and in a plan view. FIGS. 4a and 5a show the valve 30 in an open position, while FIGS. 4b and 5b show it in a closed position.

[0094] This embodiment again comprises three valve seats with respective circumferential sealing surfaces 32a-32c and respective valve partial openings 31a-31c. The valve seats or sealing surfaces 32a-32c are arranged in a common plane here. The valve partial openings 31a-31c each have the same shapes and dimensions, but are each rotated by 120° relative to the adjacent opening.

[0095] The regulating vacuum valve 30 also has three valve closures 33a-33c (valve disks) with contact surfaces 34a-34c, the sealing elements of which interact in a sealing manner with the sealing surfaces 32a-32c of the valve seats in the closed position.

[0096] Each of the valve closures 33a-33c is mounted for rotation about a respective axis of rotation. In addition, each of the valor closures 33a-33c is coupled to a respective drive component 35a-35c (motor). By means of the motors 35a-35c, the valve disks 33a-33c are rotatable about the axes of rotation in a controlled manner. The valve disks 33a-33c thus act as flaps. A surface defined by the closure side of the respective flap and a sealing plane defined by the extension of the respective sealing surface enclose a variable opening angle α in this case, with a respective opening cross-section of a valve partial opening correlating with the respective opening angle α.

[0097] Each of the motors 35a-35c is individually controllable. The regulating vacuum valve 30 also has a control or regulating unit that interacts with the motors and is designed in such a way that the motors can optionally be controlled individually or the adjustment of the flaps 33a-33c can be performed synchronously by means of corresponding control. For this purpose, the control or regulation unit has corresponding algorithms and functionalities. The flaps 33a-33c can therefore be moved simultaneously and synchronously, so that, for example, when they are moved to the closed position, they provide this closed position simultaneously.

[0098] One advantage of the rotatable bearing of the valve closures 33a-33c is to provide high-precision fine regulating functionality. In contrast to a linear valve disk movement, the folding of the closures 33a-33c enables a very fine adjustment of the opening state of the valve, especially at very low pressures, by means of very small opening state change steps, which are given due to an increasing distance of the flap to the valve seat with increasing distance from the axis of rotation (at the given opening angle α>0).

[0099] The problem of a possible snap shut at very small opening angles, which often exists with valves of the prior art, is avoided with the proposed solution by providing several valve disks and the resulting lower lever forces per valve disk.

[0100] The regulating vacuum valve 30 further comprises a first port 36 and a second port 37. At least one of the ports may be formed as a flange. The valve seats are arranged in the flow path of a flow chamber connecting the first port 36 and the second port 37.

[0101] FIG. 6 shows the regulating vacuum valve 30 according to FIGS. 4 and 5 in a perspective view. The valve seats are designed such that the valve partial openings 31a-31c defined thereby define respective opening axes 39a-39c which are aligned parallel to each other. The opening axes 39a-39c intersect the respective centers of the valve partial openings 31a-31c and extend orthogonally to a sealing plane defined by the sealing surfaces 32a-32c.

[0102] The division of the overall valve opening into a plurality of partial openings also offers the advantage that a plurality of valve closures is provided and thus the mass of each individual closure can be reduced individually. Due to the lower masses to be moved, significantly shorter adjustment times can be realized, 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 shortened.

[0103] FIG. 7 shows a process chamber 40 with a gas inlet 41 and a substrate 1 which is to be processed and is arranged in the process chamber 40.

[0104] On a side of the process chamber 40 opposite the gas inlet 41, a regulating vacuum valve 50 according to the invention which is connected to a gas outlet is provided according to a further embodiment with two valve partial openings 51a, 51b. Each valve opening is provided by a respective valve seat of the vacuum valve 50. A valve closure 53a, 53b is associated with each valve partial opening 51a, 51b. The two valve closures 53a, 53b of the valve 50 are each designed to be hinged about a respective axis of rotation. By adjusting the flaps 53a and 53b, an opening angle and thus a flow rate per time can be varied and set.

[0105] A flow of fluid through the process chamber is shown by the arrows. The specific design of the regulating vacuum valve 50 with the provision of the multiple valve partial openings 51a and 51b provides symmetrical flow of the fluid through the valve 50. Furthermore, by providing a symmetrically configured overall opening about a central valve axis Z, formed by the multiple partial openings, the outflow of the fluid from the process chamber 40 can also be carded out symmetrically (concentric).

[0106] For processing the substrate 1 preferably rests on a chuck which enables electrostatic holding of the substrate 1. The flow of the process gas can also be guided concentrically (homogeneously) around the chuck by means of the symmetrical valve opening.

[0107] Such symmetrical, homogeneous or concentric, flow behavior is very advantageous for processing substrates under vacuum or low-pressure conditions, since this results in just such a homogeneous distribution of the process gas over the substrate. As a result, e.g. deposition or etching processes can be carried out very uniformly and with high quality and reliability.

[0108] FIG. 8 shows an embodiment of a process chamber 40 with a gas inlet 41 and a processing device 45 arranged in the process chamber 40 for a substrate to be processed.

[0109] On the side of the process chamber 40 opposite, the gas inlet 41, there is again a regulating vacuum valve 50 according to the invention connected to a gas outlet and having two valve partial openings 51a, 51b. Each valve opening is provided by a respective valve seat of the vacuum valve 50. A valve closure 53a, 53b is associated with each valve partial opening 51a, 51b. The two valve closures 53a, 53b of the valve 50 are each designed to be hinged about a respective axis of rotation. By adjusting the flaps 53a and 53b, a respective opening angle and thus a respective flow rate per time can be individually varied and set for each of the valve partial openings 51a, 51b.

[0110] The processing device 45 is arranged asymmetrically in the process chamber 40. Such an arrangement of a processing device 45 is typical for providing the performance of generic vacuum processes. For example, the processing device 45 is attached to only one side of the chamber 40. Thus, the processing device 45 is not centrally located in the chamber 40, and this placement or attachment alone causes an asymmetrical flow of fluid through the chamber 40. As a result, fluid flows unevenly around the processing device 45.

[0111] Such an asymmetrical fluid flow through the chamber 40 can be compensated by means of the regulating vacuum valve 50 according to the invention. By providing different opening states of the individual valve partial openings 51a, 51b, the asymmetry with respect to the gas flow can be compensated. For this purpose, the valve closures 53a, 53b are set to different inclined positions (opening angle), whereby different opening cross-sections are provided in each case. The outflow of the fluid then no longer occurs centrally through the valve, but also asymmetrically within the valve with respect to the central axis.

[0112] Due to the different opening states, the fluid flow can be set to different degrees over the course of a chamber cross-section. In other words, the flow behavior of a gas can be set to different degrees in different areas of the chamber, e.g. different flow velocities can be set on opposite chamber walls.

[0113] By such variable adjustment of the fluid flow through the valve, an inhomogeneous, uneven flow behavior caused by the processing device 45 can be compensated for such that a resulting flow around the processing device 45 is symmetrical (homogeneous).

[0114] It is understood that the figures shown are only schematic illustrations of possible exemplary embodiments. According to the invention, the various approaches can also be combined with each other and with prior art methods and devices for regulating a volumetric flow or pressure in a process volume under vacuum conditions.