Patent ID: 12241556

FIG.1ashows a schematic cross-section of an embodiment of a regulating vacuum valve10according to the invention in a closed position.FIG.2ashows the embodiment of the regulating vacuum valve10in a plan view, also in the closed position.FIGS.1band2bshow the embodiment of the regulating vacuum valve10correspondingly in the open position.

The regulating valve10has three valve partial openings, wherein only two of the three openings11a,11bare 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 inFIGS.2aand2b.

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.

The valve partial openings11a-11care arranged symmetrically about a central axis Z of the valve10. The central axis Z is defined by a flow center of the valve10. 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.

Accordingly, the regulating vacuum valve10has a first, a second and a third valve seat. Each of the three valve seats in turn has a valve partial opening11a-11c, which are surrounded by respective sealing surfaces12a-12c. Corresponding to the valve seats, a first valve disk13a, a second valve disk13band a third valve disk13care provided. The valve disks13a-13care designed in such a way that their contact surfaces14a-14c(disk-side sealing surfaces) correspond to the sealing surfaces12a-12cof the valve seats. Accordingly, the contact surfaces each have essentially the same shape and spatial extent according to the respectively associated sealing surfaces.

Each valve disk13a-13chas 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 surface14a-14c. As an example, such a seal can be seen on contact surface14binFIG.1b. According to alternative embodiments, the sealing means can be provided alternatively or additionally on the side of the sealing surfaces12a-12c.

According to the number of valve disks, a corresponding number of drive components15a-15care provided according to this embodiment, which together form the drive unit of the valve10. Each drive component15a-15cis connected to a valve disk13a-13cby means of a coupling rod.

The drive components15a-15care designed in such a way that linear adjustability of the valve disks13a-13cis 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 disks13a-13cor the contact surfaces14a-14cis parallel to the alignment of the valve seats or the sealing surfaces12a-12cboth in the open and in the closed state.

In the embodiment shown, a motor15a-15cis associated with each valve disk13a-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 closing of the valve can thus be effected by a simultaneous opening or closing of all valve partial openings.

The three valve seats are arranged at an angle relative to each other. Each sealing surface12a-12cdefines a sealing plane by its shape and extension.

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.

Such an arrangement of the individual valve partial openings11a-11coffers the advantage of a less complex mechanism for providing the open and closed state. A linear adjustment of the disks13a-13c, which can be precisely controlled by means of the drive unit, in addition to the opening and closing of the openings11a-11c, also enables the setting of a specific opening cross-section of both each individual valve partial opening11a-11cand a resulting overall valve opening.

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.

Thus, the regulating vacuum valve10also 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 valve10, 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.

The regulating vacuum valve10further comprises a first port16and a second port17. 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 port16and the second port17.

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.

FIG.3shows another embodiment of the invention. The regulating vacuum valve20also has three valve seats and three corresponding valve disks23a-23c, which are provided for adjusting a flow rate through the respective valve partial openings21a-21c.

A first port26opposite the second port provides connectivity of the valve20to, in particular, a pipeline, a process chamber, or a vacuum pump.

Each valve disk23a-23cis mechanically coupled to a respective drive component25a-25cand 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.

Each valve disk23a-23cforms a valve assembly with its respective associated drive component25a-25c. Each valve assembly thus has—in addition to further fastening and sealing components-exactly one drive component and one valve disk. A valve assembly28consisting of valve closure23cand motor25cis referenced by way of example inFIG.3. Analogous further two such assemblies are formed by the combination of the valve closure23awith the motor25aand by the combination of the valve closure23bwith the motor25b.

As shown inFIG.3, the regulating vacuum valve20is designed such that the valve assemblies are modularly interchangeable. The housing29of the valve20, which housing29comprises 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.

The recess and the valve assembly28are formed to be adapted to each other such that the assembly28is insertable 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 assembly28.

The modular design allows comparatively simple replacement of defective or worn components. For example, the sealing elements arranged on the side of the valve disks23a-23care 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.

FIGS.4a,4band5a,5bshow a third embodiment of a regulating vacuum valve30according to the invention in cross-section and in a plan view.FIGS.4aand5ashow the valve30in an open position, whileFIGS.4band5bshow it in a closed position.

This embodiment again comprises three valve seats with respective circumferential sealing surfaces32a-32cand respective valve partial openings31a-31c. The valve seats or sealing surfaces32a-32care arranged in a common plane here. The valve partial openings31a-31ceach have the same shapes and dimensions, but are each rotated by 120° relative to the adjacent opening.

The regulating vacuum valve30also has three valve closures33a-33c(valve disks) with contact surfaces34a-34c, the sealing elements of which interact in a sealing manner with the sealing surfaces32a-32cof the valve seats in the closed position.

Each of the valve closures33a-33cis mounted for rotation about a respective axis of rotation. In addition, each of the valve closures33a-33cis coupled to a respective drive component35a-35c(motor), By means of the motors35a-35c, the valve disks33a-33care rotatable about the axes of rotation in a controlled manner. The valve disks33a-33cthus 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.

Each of the motors35a-35cis individually controllable. The regulating vacuum valve30also 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 flaps33a-33ccan be performed synchronously by means of corresponding control. For this purpose, the control or regulation unit has corresponding algorithms and functionalities. The flaps33a-33ccan therefore be moved simultaneously and synchronously so that, for example, when they are moved to the closed position, they provide this closed position simultaneously.

One advantage of the rotatable bearing of the valve closures33a-33cis to provide high-precision fine regulating functionality. In contrast to a linear valve disk movement, the folding of the closures33a-33cenables 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).

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.

The regulating vacuum valve30further comprises a first port36and a second port37. 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 port36and the second port37,

FIG.6shows the regulating vacuum valve30according toFIGS.4and5in a perspective view. The valve seats are designed such that the valve partial openings31a-31cdefined thereby define respective opening axes39a-39cwhich are aligned parallel to each other. The opening axes39a-39cintersect the respective centers of the valve partial openings31a-31cand extend orthogonally to a sealing plane defined by the sealing surfaces32a-32c.

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.

FIG.7shows a process chamber40with a gas inlet41and a substrate1which is to be processed and is arranged in the process chamber40.

On a side of the process chamber40opposite the gas inlet41, a regulating vacuum valve50according to the invention which is connected to a gas outlet is provided according to a further embodiment with two valve partial openings51a,51b. Each valve opening is provided by a respective valve seat of the vacuum valve50. A valve closure53a,53bis associated with each valve partial opening51a,51b. The two valve closures53a,53bof the valve50are each designed to be hinged about a respective axis of rotation. By adjusting the flaps53aand53b, an opening angle and thus a flow rate per time can be varied and set.

A flow of fluid through the process chamber is shown by the arrows. The specific design of the regulating vacuum valve50with the provision of the multiple valve partial openings51aand51bprovides symmetrical flow of the fluid through the valve50. 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 chamber40can also be carried out symmetrically (concentric).

For processing, the substrate1preferably rests on a chuck, which enables electrostatic holding of the substrate1. The flow of the process gas can also be guided concentrically (homogeneously) around the chuck by means of the Symmetrical valve opening.

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.

FIG.8shows an embodiment of a process chamber40with a gas inlet41and a processing device45arranged in the process chamber40for a substrate to be processed.

On the side of the process chamber40opposite the gas inlet41, there is again a regulating vacuum valve50according to the invention connected to a gas outlet and having two valve partial openings51a,51b. Each valve opening is provided by a respective valve seat of the vacuum valve50. A valve closure53a,53bis associated with each valve partial opening51a,51b. The two valve closures53a,53bof the valve50are each designed to be hinged about a respective axis of rotation. By adjusting the flaps53aand53b, a respective opening angle and thus a respective flow rate per time can be individually varied and set for each of the valve partial openings51a,51b.

The processing device45is arranged asymmetrically in the process chamber40. Such an arrangement of a processing device45is typical for providing the performance of generic vacuum processes. For example, the processing device45is attached to only one side of the chamber40. Thus, the processing device45is not centrally located in the chamber40, and this placement or attachment alone causes an asymmetrical flow of fluid through the chamber40. As a result, fluid flows unevenly around the processing device45.

Such an asymmetrical fluid flow through the chamber40can be compensated by means of the regulating vacuum valve50according to the invention. By providing different opening states of the individual valve partial openings51a,51b, the asymmetry with respect to the gas flow can be compensated. For this purpose, the valve closures53a,53bare 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.

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.

By such variable adjustment of the fluid flow through the valve, an inhomogeneous, uneven flow behavior caused by the processing device45can be compensated for such that a resulting flow around the processing device45is symmetrical (homogeneous).

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.