Vacuum processing system comprising process chamber with vacuum control valve

Abstract

To provide a vacuum control valve or a vacuum processing system that provides accurate control or adjustment of a valve aperture, provides accurate control or adjustment of a flow passing through the aperture, and provides a homogeneous fluid distribution in a process chamber.SOLUTION: A vacuum processing system 1 comprises: a vacuum valve 20 comprising a first valve seat 21a including a first valve aperture 22a defining a first aperture axis line O and a first seal surface extending so as to surround the first valve aperture and a first valve disc 23a comprising a first contact surface corresponding to the first seal surface; and a drive unit 30 connected to the first valve disc. The first valve seat divides a vacuum chamber into a main process chamber 11 and a sub process chamber 12. The first valve disc is disposed in a movable and adjustable manner in the sub process chamber.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vacuum system including a vacuum valve having a plurality of valve disks and a corresponding plurality of valve partial openings.

[0002] Generally, vacuum valves for controlling volumetric flow or mass flow and substantially gas-tightly closing a flow path through an opening machined in a valve housing are known from the prior art in various configurations and are used, in particular, in vacuum chamber systems in the fields of IC manufacturing, semiconductor manufacturing or substrate manufacturing, which must be carried out as far as possible without the presence of impurity particles in a protected atmosphere.

[0003] Such a vacuum chamber system particularly includes at least one evacuable vacuum chamber or process chamber provided for accommodating a semiconductor element or a substrate to be processed or manufactured, the vacuum chamber or process chamber having at least one vacuum chamber opening through which a semiconductor element or another substrate can be guided into and out of the vacuum chamber. The vacuum chamber system further includes at least one vacuum pump for evacuating the vacuum chamber. For example, in manufacturing equipment for semiconductor wafers or liquid crystal substrates, sensitive semiconductor elements or liquid crystal elements sequentially pass through a plurality of process vacuum chambers, and in these process vacuum chambers, the elements present inside the process vacuum chamber are each processed by one processing device. During the processing process inside the process vacuum chamber as well as during the transfer between the chambers, sensitive semiconductor elements or substrates must always be present in a protected environment - in particular in a surrounding environment without air.

[0004] For this purpose, first, a peripheral valve for opening and closing a gas supply part or a gas discharge part is used, and second, a transfer valve for opening and closing a transfer opening provided in a vacuum chamber for introducing and removing elements is used.

[0005] Vacuum valves through which semiconductor elements pass are called vacuum transfer valves, based on the aforementioned fields of use and, consequently, on their associated dimensional settings; also called square valves, based on their predominantly square opening cross-section; and further called slide gate valves, square gate sliders, or transfer slide gate valves, based on their usual functional form.

[0006] In contrast, peripheral valves are used specifically to control the gas flow between a vacuum chamber and a vacuum pump or another vacuum chamber in an open-loop or closed-loop manner. Peripheral valves are located, for example, within a tubular system between a process vacuum chamber or transfer chamber and a vacuum pump, environment, or another process vacuum chamber. The opening cross-section of such valves, also called pump valves, is generally smaller than that of vacuum transfer valves. Peripheral valves are also called control valves because, depending on the field of use, they are used not only to completely open and close their openings but also to control the flow in an open-loop or closed-loop manner by continuously adjusting the opening cross-section between a fully open position and a gas-tight closed position. One possible peripheral valve for controlling gas flow in an open-loop or closed-loop manner is a pendulum valve.

[0007] For example, in a typical pendulum valve known pursuant to U.S. Patent No. 6,089,537 (Olmsted), in the first step, a valve disc, which is generally circular, is rotated to an intermediate position covering an opening, which is generally also circular. In the case of a slide gate valve, for example, as described in U.S. Patent No. 6,416,037 (Geiser) or U.S. Patent No. 6,056,266 (Blecha), the valve disc and opening are usually rectangular, and in this first step, the valve disc is moved linearly from an opening to an intermediate position covering the opening. At this intermediate position, the valve disc of the pendulum valve or slide gate valve is positioned opposite to the valve seat surrounding the opening, spaced apart. In the second step, the gap between the valve disc and the valve seat is reduced so that the valve disc and the valve seat are uniformly pressed against each other, and the opening is closed substantially gas-tight. This second movement is preferably performed substantially perpendicular to the valve seat. The sealing may be performed, for example, via a sealing ring positioned on the closed side of the valve disc and pressed against the valve seat surrounding the opening, or via a sealing ring provided on the valve seat. In the case of a sealing ring provided on the valve seat, the closed side of the valve disc is pressed against it. The closing process, which takes place in two steps, hardly exposes the sealing ring between the valve disc and the valve seat to any shear forces that could destroy the sealing ring, because the movement of the valve disc in the second step is substantially linear and perpendicular to the valve seat.

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

[0009] The aforementioned multi-stage motion, in which the closing element is first moved orthogonally to cover the opening without contact between the sealing member and the valve seat, and then the closing element is pressed substantially vertically against the valve seat, offers the advantage of preventing lateral or longitudinal loading of the sealing member (particle avoidance) and ensuring that the sealing member is compressed only substantially vertically, as well as providing the possibility of controlling the flow of a medium (e.g., process gas) through the valve opening in a closed-loop manner.

[0010] The valves mentioned above are used particularly in the manufacture of highly sensitive semiconductor devices, and as already stated, the number of particles generated, especially those caused by the operation of the valve and the mechanical load of the valve closing element, as well as the number of free particles in the valve chamber, must be kept as low as possible. Particle generation is primarily the result of friction, for example, due to metal-to-metal contact or abrasive wear.

[0011] As explained above, vacuum control valves are used to regulate a defined process environment within a process chamber. Closed-loop control in this case is typically performed with respect to a pressure signal that provides information about the chamber pressure and a target quantity to be achieved by the closed-loop control, namely the target pressure. The position of the valve closure (valve disc) is then changed within the framework of the closed-loop control so that the target pressure is achieved within a specified time.

[0012] In this case, the time required for adjustment is directly related to the size of the volume of the process chamber to be evacuated. Therefore, a relatively large chamber can be inconvenient, especially when processing small substrates. In other words, it is desirable to avoid large dead volumes accordingly.

[0013] What the above configurations have in common is that, especially in the case of closed-loop control, the control curve (volume flow per unit time) produced by one of these structures typically exhibits an undesirable curve progression. In particular, the curve during the transition from a nearly closed valve state to a fully closed valve state shows a remarkably non-uniform curve progression based on the "snap-shut effect" that occurs at this time. At this point, the flow through the opening is abruptly blocked. As a result, precise control at extremely low pressures becomes extremely difficult, or even impossible.

[0014] Another critical factor in semiconductor manufacturing is the use and handling of process gases required for each processing step. In this case, the control valve typically also undertakes the function of providing a specified gas concentration, i.e., adjusting the specified gas concentration by a variable gas flow through the valve. The process gas is usually supplied in this case on the side of the process chamber opposite the exhaust opening.

[0015] In this case, in addition to gas concentration and ambient pressure, at least a homogeneous distribution of the process gas in the region of the substrate to be processed is also advantageous. To achieve this, a symmetrical flow of gas through the process chamber, that is, a symmetrical flow both during gas supply and exhaust, can be effective.

[0016] U.S. Patent No. 6,994,311 discloses a vacuum control valve intended to form a symmetrical flow through an opening in an open valve position. The valve disc is suspended in the center by a guide (valve rod) and can be guided axially so that the volumetric flow through the opening can be adjusted in relation to the distance between the valve disc and the valve seat. However, this solution also has the drawback that a mechanical coupling to the center of the valve opening must exist to provide a guide for the valve disc. This mechanical coupling disrupts the flow symmetry, at least partially, and creates turbulence at the coupling member.

[0017] The fundamental problem of this invention is to provide a vacuum control valve or vacuum processing system that, on the one hand, provides precise control or adjustment of the valve opening, and consequently provides precise control or adjustment of the flow through the opening, and on the other hand, provides a homogeneous fluid distribution within the process chamber.

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

[0019] Another challenge is to provide a processing system that offers precise control of fluid flow and relatively small process volumes.

[0020] These challenges are resolved by implementing the features described in the independent claims. Features that optionally or advantageously improve the invention are described in the dependent claims.

[0021] The present invention relates to the structure of a vacuum processing system having at least one vacuum chamber or process chamber and a vacuum valve, particularly a vacuum control valve. The vacuum valve provides improved flow and outflow of process fluid from the process volume in terms of homogeneity of flow characteristics. At the same time, the adjustment time required for changing from an open state to a closed state (or from a closed state to an open state) can be significantly improved, i.e., shortened. In the configuration of the present invention, the vacuum chamber is divided into a main chamber and a sub-chamber by a valve, in this case the valve is located inside the vacuum chamber.

[0022] The advantages and improvements mentioned above are provided, in particular, by dividing the valve opening, which was previously a single unit as known in the prior art, into multiple valve sub-openings of the vacuum valve. These valve sub-openings are preferably arranged symmetrically around a central valve axis. Each valve sub-opening is provided by a single valve seat and surrounded by a sealing surface. The sum of the areas of the multiple valve sub-openings gives the area of ​​the entire valve opening.

[0023] The total valve open cross-section is obtained from the sum of the open cross-sections of multiple valve partial openings, in which case the open cross-section is related to the open state of the valve partial opening at any given time, that is, to the flow surface opened by each valve closure.

[0024] The valve seat forms a lower demarcation in particular of the main process chamber and an upper demarcation of the sub-process chamber. The sealing member for forming a gas-tight closure of the main process chamber is preferably located below the valve seat, i.e., located in the sub-process chamber rather than in the main process chamber. Correspondingly, the valve disc for closing the opening is located in the sub-process chamber and can be moved along an adjustment axis within this sub-process chamber. Alternatively or additionally, this sealing member may be located on the side of the valve disc.

[0025] Because the valve disc, including its drive components, is located within or attached to the sub-process chamber, the valve does not affect the fluid flow into or through the main process chamber. This allows for improved symmetrical flow (throughflow) and, consequently, improved substrate processing within the main process chamber.

[0026] The valve seat is preferably arranged around a central chuck, in which case the fluid flow can be carried out by a homogeneous flow distribution around the chuck.

[0027] In other words, the present invention relates to a vacuum processing system for processing substrates or workpieces, particularly semiconductors, by deposition (ALD, atomic layer deposition / epitaxy) or etching (ALE, atomic layer etching).

[0028] The vacuum processing system includes a vacuum chamber that generates a vacuum and defines an evacuable internal volume for processing a substrate within the internal volume. Further, the vacuum processing system includes a vacuum control valve for controlling the volumetric flow or mass flow of a fluid flowing through the vacuum chamber and for gas-tightly shutting off the fluid flow path.

[0029] The vacuum control valve includes at least one first valve seat having a first valve opening defining a first opening axis and a first seal surface extending so as to surround the first valve opening, and at least one first valve disk having a first contact surface corresponding to the first seal surface.

[0030] The vacuum processing system includes at least one drive unit configured such that the first valve disk is movable (e.g., powered) at least from an open position to a closed position and from the closed position to the open position and is connected to the first valve disk in this way. In the open position, the first valve disk and the first valve seat are in a non-contact relative position to each other. In the closed position, a tight contact occurs between the first seal surface and the first contact surface via an intervening seal member, thereby gas-tightly closing the first valve opening.

[0031] According to the present invention, the first valve seat is disposed inside the vacuum chamber, which divides the vacuum chamber into a main process chamber for processing the substrate and a sub-process chamber. The first seal surface extends in a direction orthogonal to the first opening axis and is directed toward the sub-process chamber, particularly parallel to the first opening axis. The first valve disk is disposed movably adjustably within the sub-process chamber.

[0032] In one embodiment, the vacuum control valve may have a second valve seat having a second valve opening defining a second opening axis and a second sealing surface extending to surround the second valve opening, and a second valve disc having a second contact surface corresponding to the second sealing surface. The second valve seat is located inside the vacuum chamber and, together with the first valve seat, may divide the vacuum chamber into a main process chamber and a sub-process chamber. The second sealing surface extends in a direction perpendicular to the second opening axis and is oriented toward the sub-process chamber, particularly parallel to the second opening axis. The second valve disc may be movably and adjustablely located within the sub-process chamber.

[0033] As a result, the entire valve opening of the vacuum control valve may be formed by at least a first valve opening which is a first valve partial opening and a second valve opening which is a second valve partial opening.

[0034] By providing at least two groups, each including at least one valve seat and a valve closure (valve disc), a symmetrical arrangement around the center of the vacuum valve becomes possible. This provides, on the one hand, symmetrical volumetric flow through the valve, and on the other hand, relatively rapid operation with the possibility of extremely flexible volumetric flow control (i.e., rapid movement adjustment of the valve closure based on the relatively small individual mass of the valve closure), which may also provide achieving a relatively large overall open cross-section from the closed position (and vice versa) in a short time.

[0035] In one embodiment, the vacuum processing system may have a third valve seat. The third valve seat has a third valve opening that defines a third opening axis and a third sealing surface that extends to surround the third valve opening. Correspondingly, a third valve disc may be provided, having a third contact surface corresponding to the third sealing surface.

[0036] The third valve seat is located inside the vacuum chamber and, together with the first and second valve seats, may divide the vacuum chamber into a main process chamber and a sub-process chamber. The third sealing surface extends in a direction perpendicular to the third opening axis and may be oriented toward the sub-process chamber, particularly parallel to the third opening axis. The third valve disc may be movably and adjustablely positioned within the sub-process chamber.

[0037] In this case, the entire valve opening may be further formed by a third valve opening, which is a third valve partial opening.

[0038] A third or further arrangement of the valve seat and valve disc can provide or enhance the overall symmetry of the valve opening around the central axis of the valve, thereby further improving the symmetry of the volumetric flow passing (concentrically) through the valve.

[0039] In particular, the drive unit may be connected to a second or third valve disc, in which case the connected valve disc can be adjusted to move from each open position, where each valve disc and each valve seat are relatively uncontacted to each other, to a closed position, where close axial contact is created between each sealing surface and each contact surface via the interposed sealing members, thereby closing each valve partial opening in a gas-tight manner, and then back to the open position.

[0040] The drive unit may be configured, for example, as an actuator or electric motor, particularly a linear motor or a stepping motor.

[0041] In one embodiment, the vacuum control valve may have a coupling device that provides a mechanical coupling between a first valve disc, a second valve disc, and especially a third valve disc, such that each valve disc can be moved and adjusted together by a drive unit, and is thus coupled to the drive unit. The coupling device may be implemented, for example, by a shaft, a joint (e.g., a cardan coupling), a bearing, and / or a transmission.

[0042] In other words, a mechanical solution may be provided to adjust the simultaneous movement of, for example, multiple or all connected valve discs. This can achieve a homogeneous and symmetrical fluid flow through the valves, based on the fact that an equal opening cross-section is already provided for all openings when the valve partial openings are first opened, and the flow through all openings is equal in terms of volumetric or mass flow and continues to be equal.

[0043] In another embodiment, the drive unit may have at least one first drive component and a second drive component, in particular a third drive component, in particular each motor. The first drive component may be coupled to a first valve disk, the second drive component may be coupled to a second valve disk, and in particular the third drive component may be coupled to a third valve disk.

[0044] Unlike previous embodiments, in this variation, each valve disc can be individually controlled and moved. This allows for greater flexibility in regulating the flow characteristics through the valve, particularly through the main process chamber. For example, this can compensate for volumetric flow asymmetry caused by the asymmetrical arrangement of processing devices or multiple fluid inlets within the process chamber. Such compensation can be achieved by providing different opening cross-sections for the individual valve partial openings.

[0045] In particular, the flow characteristics within the chamber can be adjusted to compensate for asymmetrical flows caused, for example, by equipment within the chamber for processing substrates. With conventional valves, the flow proceeds correspondingly heterogeneously through the process chamber. The valves of the present invention allow for adjustment of the outflow characteristics, so that the fluid outflow can prevent asymmetrical flows through the chamber, resulting in a symmetrical flow overall through the chamber. The flow through the valves in this case may proceed correspondingly asymmetrically (not concentrically, i.e., asymmetrically with respect to the central axis). For example, different flow velocities may exist on different valve sides (e.g., located on opposite sides).

[0046] In one embodiment, the drive unit, particularly each drive component, and at least a first valve disc (or a second, third, or fourth or later valve disc) may be connected such that at least the first valve disc among these valve discs is movable and adjustable along a first adjustment axis, and this first adjustment axis extends in a direction that intersects a first opening axis relative to it. Of course, the number of valve discs preferably corresponds to the number of valve seats. That is, a single valve may have multiple (more than three) valve seats and a corresponding number of valve discs.

[0047] In one embodiment, the main process chamber may encompass the main internal volume, and the sub-process chamber may encompass the sub-internal volume, in which case the main internal volume is larger than the sub-internal volume.

[0048] In one embodiment, the vacuum processing system may have an electrostatic holding device, particularly a chuck, located within the main process chamber.

[0049] The vacuum control valve may have at least a first valve seat and at least two other valve seats, which may define a first valve opening and at least two other valve openings. These valve seats may be arranged symmetrically around an electrostatic retaining device.

[0050] In one embodiment, the valve seat and / or valve opening may be formed in a ring segment shape, and each inner arc or each outer arc of the ring segment valve seat or valve opening may be positioned along a common circle.

[0051] The chuck may be formed, for example, in a circular shape and / or may define a circular surface that is a holding surface for the substrate. Based on an overall annular arrangement of valve openings surrounding the chuck, correspondingly optimized fluid flow characteristics can be achieved around the chuck and around its entire circumference.

[0052] In one embodiment, the first valve partial opening and the second valve partial opening, and in particular the third valve partial opening, may be arranged symmetrically with respect to the central axis of the vacuum control valve, in which case this central axis extends through the valve center point and in particular forms the central axis of the flow passage. The valve may, based on its geometric shape, define a flow path for the fluid on the one hand, and thereby define a defined flow passage for the fluid on the other hand. This central axis is located in particular at the center of the flow passage and extends in proportion to the length of the flow passage. The center point of the chuck mounting surface is located in particular at this central axis.

[0053] Using the valve of the present invention, the flows described above can be advantageously regulated, even at very low pressures, to provide and maintain substantially symmetrical and layered flows.

[0054] The vacuum control valve may have a control unit, in particular a closed-loop control unit, in which case the drive unit (and its drive components) is controllable with respect to a control signal provided by the control unit, in particular a control quantity for closed-loop control.

[0055] In particular, each drive component of the drive unit may be individually controllable by (separate) control signals.

[0056] In one embodiment, the control unit may have a flow function configured such that at least one of the valve disks connected to the drive unit moves to an intermediate position between an open position and a closed position during its operation.

[0057] In particular, the at least one connected valve disc may be linearly movable and adjustable along the adjustment axis, and the distance between the contact surface of the valve disc and the corresponding sealing surface at an intermediate position may be smaller than in the open position and larger than in the closed position.

[0058] In one embodiment, the vacuum control valve may have at least first and second valve seats, first and second valve discs, and further, a first drive component connected to the first valve disc and a second drive component connected to the second valve disc. In this case, the flow functionality may be configured such that the valve discs can be individually positioned between each open position and each closed position in relation to predetermined flow information.

[0059] Such intended relative and individual opening positions between the valve seat and valve closure, and the thereby adjustable opening region of the valve opening, enable advantageous closed-loop pressure and flow control. Such closed-loop control can typically be used, for example, when process gases are used and, in connection there is a need to adjust a target pressure. The resulting sustained, layered flow of the medium through the opening and, in particular, the main process chamber, can avoid pressure fluctuations and allow a predetermined target pressure to be achieved more quickly.

[0060] In particular, individual disk positions (intermediate positions) can be controlled (using control signals) and adjusted individually and continuously, thereby providing particularly continuous closed-loop control of the volumetric or mass flow of the medium through the valve opening. In this case, the flow can be maintained particularly in layers. Such closed-loop control is provided, in particular, by a stepping motor or servo motor of the drive unit.

[0061] The flow information specifically includes the following: ● Mass flow or volumetric flow of fluid through the main process chamber and / or sub-process chamber, ● Fluid velocity in the main process chamber and / or sub-process chamber, ● Flow velocity distribution with respect to the internal volume cross-section for the main process chamber and / or sub-process chamber, ● Pressure difference between the main process chamber and the sub-process chamber, ● Fluid inflow into the main process chamber, ● Fluid outflow from the sub-process chamber, They may have or be able to provide at least one of the following.

[0062] The control unit may allow individual valve discs to be individually positioned so as to provide symmetric fluid flow through the main process chamber in relation to flow information. This can be achieved, for example, by adjusting and / or dynamically adjusting different opening cross-sections for individual valve partial openings in the case of unequal fluid distribution in one of several process chambers, or spatially unequal fluid inflow into the main process chamber. However, this can also be achieved, for example, by adjusting equal opening cross-sections for valve partial openings when the fluid distribution or inflow is homogeneous.

[0063] In one embodiment, the positioning of the valve discs may be individually and dynamically adjustable, thereby providing continuous closed-loop control of the fluid flow through the main process chamber. For example, when the fluid distribution within the process chamber is changed, such as when a new process gas or another process gas is supplied, the valve disc positions may be adjusted during or before the processing process.

[0064] In one embodiment, the defined flow characteristics may be adjustable by a vacuum control valve, particularly by at least two valve partial openings, and / or be controllable in a closed loop, in particular in this case the flow characteristics are adjustable by the vacuum control valve asymmetrically with respect to the central axis of the vacuum control valve, which extends through the valve center point.

[0065] In one embodiment, if a heterogeneous fluid flow is present through the main process chamber, a symmetrical fluid flow can be regulated by performing a flow function.

[0066] The vacuum processing system includes, in particular, at least one sensor unit, specifically a pressure sensor or a sensor for chemical analysis of gas composition. The sensor unit is configured such that flow information can be detected by this sensor unit.

[0067] In one embodiment, the flow path may connect the main process chamber and the sub-process chamber, in which case the main process chamber can be gas-tightly separated from the sub-process chamber by a vacuum control valve. That is, the flow path can be closed.

[0068] In one embodiment, the first valve seat and the second valve seat may be arranged in a common plane. In an alternative embodiment, the first valve seat and the second valve seat may be arranged obliquely to each other, in which case the plane defined by the first sealing surface and the plane defined by the second sealing surface form a defined angle. The valve seats may be oriented, for example, such that the defined sealing plane includes one side of each of the virtual pyramids.

[0069] In one embodiment, this orientation may be adjusted so that the opening axes defined by each valve opening of the valve seat intersect with each other, particularly at a common intersection. This common intersection is located in particular on the central axis of the valve.

[0070] In one embodiment, the drive unit includes at least one motor and at least one guide component, in particular a valve rod or guide rod, which is controlled by the at least one motor and moves along an adjustment axis, in which case the valve disc is moved relative to the valve seat by the guide component.

[0071] The position of the adjustment axis is defined in particular by the extending length of a guide component, which is configured as, for example, a push rod, valve rod, or guide rod, and / or the linear direction of motion provided by the drive unit.

[0072] In one embodiment, the vacuum processing system or vacuum control valve may have a separation device for separating the process atmosphere region from the external atmosphere region. This is particularly relevant to the configuration of the control valve as a vacuum valve.

[0073] The process atmosphere region can be understood as the region that may be defined in particular by the process chamber (vacuum chamber). In this region, a process atmosphere for processing the substrate, particularly a vacuum, may be formed. Components provided for this region must satisfy enhanced requirements, for example, in terms of material resistance and atmospheric purity (particle generation). The external atmosphere region can be understood, in particular, as the region surrounding the process chamber, where, for example, standard atmospheric conditions, such as room air, are present.

[0074] The drive unit may be positioned at least partially, and especially completely, to correspond to the external atmosphere region, and the valve seat and valve closure may be positioned particularly to correspond to the process atmosphere region.

[0075] The separation device may be formed, for example, by a bellows. The bellows may be located, for example, inside the valve housing or inside the drive unit.

[0076] For example, a vacuum control valve in a vacuum processing system, particularly a drive unit, may have a drive housing in which a valve rod for moving a valve disc is movably supported. The valve rod extends from the drive housing into a sub-process chamber (process atmosphere region) on one end and is connected to a motor, for example, by a transmission, on the other end. In this case, a separation device (e.g., a dynamic bellows) may be provided, with a first end of the separation device gas-tightly coupled to the housing (or another static element within the drive housing) and a second end to the valve rod. This allows for atmospheric separation of the valve rod support from the critical process atmosphere region in terms of atmospheric purity, where relative motion may cause particle formation and where lubricants may be used (external atmosphere region), while simultaneously providing controlled mobility of one or more valve discs.

[0077] The housing may be made from, for example, aluminum or special steel, or the inside may be coated with aluminum or another suitable material, while the valve disc and bellows may be made of steel. The bellows may optionally or additionally have a nickel-based alloy, or may be made from a nickel-based alloy. The bellows, which is expandable and contractible along its longitudinal axis within the range of the valve disc's adjustment stroke, airtightly seals the process atmosphere region from the external atmosphere region. Two types of bellows are used in particular: on the one hand, diaphragm bellows, and on the other hand, corrugated bellows. Corrugated bellows are characterized in the following respects compared to diaphragm bellows: namely, corrugated bellows have no weld seams and can be cleaned more easily, but they have a smaller maximum stroke.

[0078] The apparatus of the present invention will be described in detail below, purely illustrative, with reference to specific embodiments schematically illustrated in the drawings. In this case, other advantages of the present invention will also be discussed. [Brief explanation of the drawing]

[0079] [Figure 1] This figure shows a first embodiment of the vacuum processing system according to the present invention. [Figure 2] This figure shows one embodiment of a vacuum valve in a vacuum processing system according to the present invention. [Figure 3] This figure shows one embodiment of a vacuum valve in a vacuum processing system according to the present invention.

[0080] Figure 1 shows a side cross-sectional view of a first embodiment of a vacuum processing system 1 comprising a vacuum chamber 10 (process chamber) and a vacuum control valve 20. The vacuum control valve 20 is formed to control the volumetric or mass flow of fluid flowing through the vacuum chamber 10 and to gas-tightly shut off the fluid flow path. For this purpose, the vacuum control valve 20 has a valve seat 21a, which defines a valve opening 22a having an opening axis O. The vacuum control valve 20 further has a valve disc 23a. The lower side of the valve seat 21a provides a sealing surface, in which case the valve disc 23a has a contact surface (the sealing surface on the valve disc side). This contact surface is designed to bring into contact with the sealing surface (on the valve seat side), thereby enabling gas-tight closure of the vacuum control valve 20. Contact is achieved particularly indirectly by a sealing member provided between the sealing surface on the valve seat side and the sealing surface on the valve disc side. In this case, even if the structural elements, the valve seat and the valve disc, are in physical contact only indirectly (i.e., only indirectly through a sealing member interposed between the two elements), this state shall be interpreted as a "contact state."

[0081] The valve disc 23 is movable by the drive unit 30 from an open position (shown in Figure 1) to a closed position (not shown). That is, in the closed position, close contact occurs between the sealing surface and the contact surface via the interposed sealing member. At this time, the valve opening 22a is closed in a gas-tight manner.

[0082] The sealing member may be a polymer-containing sealing member, which is positioned below the valve seat 21a by clamping, bonding, or vulcanization. The sealing member may be configured as, for example, an O-ring. In an alternative configuration, the sealing member may be positioned on the valve disc 23a.

[0083] The drive unit 30 may be, for example, an electrically operated actuator or motor (e.g., a linear motor or a stepping motor) having a linear adjustment axis V. The drive unit 30 can provide a stroke of at least 50 mm, and in particular 100 mm.

[0084] The valve seat 21a is located inside the vacuum chamber 10. The vacuum chamber 10 is divided into a main process chamber 11 for processing substrates and a sub-process chamber 12 by the valve seat 21a, and by a location where gas-tight closure can be achieved (seal line).

[0085] The vacuum chamber 10 is connected to a post-connected vacuum generator, particularly a vacuum pump, for generating a vacuum within the sub-process chamber 12 via a lower opening 19. A vacuum valve and / or pressure sensor may be provided as another post-connected component.

[0086] The vacuum control valve 20 is mounted in the vacuum chamber 10 such that the first sealing surface of the valve seat 21a extends in a direction perpendicular to the opening axis O and is oriented parallel to the first opening axis O in the direction toward the sub-process chamber 12. The valve disc 23a is correspondingly positioned within the sub-process chamber 12 so as to be movable and adjustable.

[0087] In the illustrated embodiment, the valve disc 23a is supported by the guide element 24a. This support is particularly formed so that the valve disc 23a can tilt (slightly) relative to the guide element 24a. The drive unit 30 is connected to the guide element 24a by a valve rod 31, thereby allowing the valve disc 23a to be adjusted by the drive unit 30.

[0088] In another embodiment, the valve disc 23a may be directly connected to the valve rod 31. In this case, the valve disc 23a may be tiltable within a relatively narrow range relative to the valve rod so that the contact surface can be in complete contact with the sealing surface. Such tilting can provide reliable closure of the valve opening 22a, particularly when the adjustment axis V is positioned obliquely relative to the opening axis O. The oblique arrangement shown in the illustration allows for particularly advantageous space utilization, in which case the adjustment device (e.g., the valve rod) requires relatively little space within the vacuum chamber 10, and the drive unit 30 can be positioned in an advantageous manner with respect to the surrounding vacuum elements. Downstream elements, which may exist, can in this case be connected to the sub-process chamber 12 without any problems, i.e., without the drive unit 30 creating spatial constraints.

[0089] Of course, the valve disc may be selectively and rigidly coupled to the valve rod. In that case as well, the valve disc may be coupled to the valve rod such that the adjustment axis V forms an angle of 0° to 90° with the plane defined by the sealing surface on the valve seat side, that is, it is positioned in a direction intersecting this plane.

[0090] The drive unit 30 may further have a bellows for atmospheric isolation of the internal volume of the process chamber 10 (process atmosphere region) from the external atmosphere (external atmosphere region). For this purpose, the bellows may be coupled to the valve rod 31 on one side and to, for example, the inner drive housing on the other side. This can provide atmospheric isolation between the movable parts of the drive unit and the internal volume of the process chamber 10. In this way, particle intrusion caused by, for example, wear can be prevented. The bellows are in a compressed state when the valve is open and in an extended or deployed state when the vacuum control valve 20 is closed.

[0091] Embodiments of the present invention offer the following advantages: the volume of the main process chamber 11 in which the substrate is effectively processed can be kept relatively small, and consequently, the desired internal pressure within the main process chamber 11 for a particular processing process can be adjusted relatively quickly.

[0092] The sub-process chamber 12 provides a larger internal volume than the main process chamber 11. Within this internal volume, the internal pressure can be adjusted to a target processing pressure or lower by suction through the opening 19. Thus, the sub-process chamber 12 is used as a reserve volume for the main process chamber 11, providing rapid adjustment of the process pressure within the main process chamber 11.

[0093] Figure 2 shows a plan view of the vacuum control valve of the vacuum processing system shown in Figure 1. The vacuum control valve has a total of three valve seats 21a to 21c, which are arranged in an annular pattern. Each valve seat 21a to 21c provides one valve opening 22a to 22c. In the illustrated embodiment, these valve openings 22a to 22c are provided with a grid-like structure, which allows for homogeneous fluid flow through each opening. In an alternative embodiment, the valve openings 22a to 22c may be configured without the illustrated structure, or with an alternative fluid-permeable structure.

[0094] Below each valve seat 21a to 21c (see Figure 3, not shown in Figure 2), there are corresponding valve closures 23a to 23c, as illustrated, for example, in Figure 1 with respect to the valve seat 21a and valve disc 23a. Each valve closure is connected to an individually controllable drive unit (a corresponding number of drive components are provided, corresponding to the number of valve discs).

[0095] This allows for individual adjustment of the opening cross-section and, consequently, individual flow for each valve opening 22a to 22c. That is, the mass flow or volumetric flow of the fluid can be adjusted individually and independently for each valve opening, separate from each other. Based on this individual adjustability, a symmetrical fluid flow, particularly through the main process chamber 11, can be provided. To this end, for example, different offsets can be adjusted for each individual valve opening. This can compensate for heterogeneous pressure and flow distributions.

[0096] By providing the process fluid through the process chamber with the most symmetrical and homogeneous flow possible, substrate processing can be carried out with corresponding accuracy and precision. Symmetrical flow ensures, for example, that comparable or equal process gas concentrations exist across the (entire) substrate surface, and that processes such as deposition or etching (e.g., ALD or ALE processes) are carried out correspondingly and homogeneously along the surface.

[0097] The valve seats 21a to 21c of the vacuum control valve are arranged symmetrically around the electrostatic holding device 15 (chuck). The substrate to be processed is lowered onto the holding device 15 and can be held there by the corresponding electrostatic charge. In other words, the chuck 15 is designed to house the substrate and hold it there, at least for the duration of the processing.

[0098] This concentric arrangement of the chuck 15 and valve seats 21a-21c allows for optimized symmetry or homogeneity of the fluid flow. This ensures that the chuck 15 is surrounded by a sufficiently homogeneous flow around its entire circumference. Simultaneously, the flow rate can be individually controlled by the individual valve openings 22a-22c. As a result, this can provide correspondingly greater homogeneity with respect to substrate processing.

[0099] Furthermore, by positioning the valve near and around the chuck 15, advantageous restriction of particle flow or particle flow conductance in the region of the chuck 15 (especially in the closed position) is provided. This ensures that the valve's seal line is located relatively close to the chuck 15, i.e., close to the substrate processing location. This directly results in improved (homogeneous) substrate processing.

[0100] By bringing the valve disc closer to the corresponding valve seats 21a to 21c, for example, in a step-by-step manner, the open cross-section of the valve portion opening can be reduced step-by-step, particularly continuously.

[0101] This also provides the vacuum control valve 20 with the possibility of intentionally regulating the fluid flow through one or more valve openings. That is, if it is desired to provide a specified internal pressure within the main process chamber, the vacuum control valve 20 can regulate the specified amount (mass or volume) of fluid flowing out per unit time. In this case, the internal pressure within the main process chamber 11, detected, for example using a pressure sensor, can be used as the control variable for closed-loop control. Alternatively, the open cross section can be controlled, regulated, and altered in an open-loop manner based on predetermined rules.

[0102] For the sake of clarity, it should be added that the present invention is not limited to embodiments having three valve partial openings, valve seats, and valve discs, but also encompasses solutions having two or more valve openings, valve seats, and valve discs, respectively.

[0103] Dividing the entire valve opening into multiple valve partial openings 22a to 22c offers further advantages. Specifically, multiple valve closures 23a to 23c are also provided, thereby individually reducing the mass of each valve closure. This can result in significantly shorter adjustment times based on the reduction in the individual masses that need to be moved. In other words, the time required to adjust one or all of these valve closures from the open position to the closed position (or from the closed position to the open position) can be reduced.

[0104] Furthermore, the probability of an undesirable valve snap shut occurring, which can occur in the case of extremely small valve openings, can be reduced. This is because the force applied to each individual valve disc is significantly smaller than the force applied to a single connected valve disc of the same area, and consequently, the holding force acting against this force can be structurally implemented more simply.

[0105] The initially asymmetric fluid flow through the main process chamber 11 can be compensated by the vacuum control valve 20 according to the present invention. Furthermore, asymmetry with respect to the gas flow can be compensated by providing different opening states for the individual valve partial openings 22a to 22c, which are dynamically adaptable. To this end, the valve closures 23a to 23c can be brought to different positions (different spacings relative to each valve seat). This provides each of them with a different opening cross-section. In this case, the fluid outflow no longer occurs concentrically through the valve, but asymmetrically with respect to the central axis even within the valve.

[0106] Different opening conditions allow the fluid flow to be regulated to varying strengths across the chamber's cross-sectional shape. In other words, the gas flow characteristics can be characterized and regulated differently in different regions of the chamber. For example, different flow velocities can be regulated in the chamber walls located on opposite sides of the chamber.

[0107] Based on this variable adjustment of the fluid flow by the vacuum control valve 20, heterogeneous and unequal flow characteristics, for example, caused by the non-center inflow of process gas, can be compensated for, in this case, so that the heterogeneous and unequal flow characteristics are compensated for so that the combined flow flowing around the chuck 15 is symmetrical (homogeneous).

[0108] Figure 3 is a perspective view showing an embodiment of the valve seat 21 together with the corresponding valve disc 23 of the vacuum processing system according to the present invention.

[0109] The valve seat 21 is represented by a plate having the shape of a ring segment. The valve seat 21 defines a valve opening 22 through which a fluid (e.g., process gas or precursor) can flow. The valve opening 22 is surrounded by a sealing surface having a sealing member 25 around its entire circumference. The sealing member 25 (and sealing surface) is located on the underside of the valve seat 21, i.e., on the side opposite to the main process chamber 11 in its assembled, specified state.

[0110] Furthermore, the valve seat 21 has a structure on its upper side, opposite to the lower side, that is permeable to and through which process fluid can pass. This structure may be formed, for example, as a grid, a perforated sheet, or a thin flake. This structure provides increased stability of the valve seat 21 and homogenization of fluid flow. That is, the flow can be divided into individual subflows by the multiple passages provided by this structure, thereby achieving improved laminar flow characteristics.

[0111] In an alternative configuration, the valve seat 21 may be formed without any structure.

[0112] The plate-like configuration of the valve seat 21 allows for easy and rapid assembly or replacement of the valve seat 21 in a vacuum processing apparatus, such as the one illustrated in Figure 1. The valve seat plate 21 can be fitted into and secured within the process chamber (main process chamber 11) from above, and can also be removed from above without the need for the cumbersome removal of other valves or chambers. The valve seat plate 21 can be supplied or removed, for example, through a transfer opening (not shown) provided in the process chamber, which is used to introduce and / or remove substrates to be processed into the chamber.

[0113] The shape and spatial extension of the valve disc 23 correspond to the valve seat 21, particularly the sealing member 25. By pressing the valve disc 23 against the sealing member 25 from below, the valve opening 22 can be closed to a gas-tight seal. The upper side (not visible) of the valve disc 23 has a contact surface, which corresponds to the shape and spatial extension of the sealing member 25 or the sealing surface supporting the sealing member 25. When the valve is closed, this contact surface comes into contact with the sealing member 25.

[0114] The lower side of the valve disc 23 further has a connecting element 26 for connecting the drive unit to the valve disc 23.

[0115] The valve disc 23, like the valve seat, can be assembled from above, particularly within the sub-process chamber 12, in the vacuum processing system according to the present invention. For this purpose, the valve disc 23 can be supplied or removed, for example, through a transfer opening (not shown), also provided in the process chamber, which is used to introduce and / or remove the substrate to be processed into the chamber.

[0116] This makes it relatively easy to remove and / or install the valve seat 21, as well as the valve disc 23, which is particularly advantageous in terms of predictive / preventive maintenance or, in some cases, repair work. For example, the sealing members located on the valve seats 21a-21c are subjected to material loads by any movement adjustment to or from the closed position, and therefore the sealing members must be replaced or replaced in a regular cycle. Based on the advantageous modular structure, significant time savings can be achieved for this maintenance work compared to conventional valve solving methods.

[0117] Of course, the drawings are merely schematic representations of possible embodiments. According to the present invention, various features can be combined with each other, and can also be combined with prior art methods and apparatus for controlling volumetric flow or pressure within a process volume under vacuum conditions.

Claims

1. A vacuum processing system (1), comprising: a vacuum chamber (10) defining an evacuable interior volume for generating a vacuum and processing a substrate within the interior volume; a vacuum control valve (20) for controlling the volumetric or mass flow of fluid through the vacuum chamber (10) and for gas-tightly blocking the fluid flow path; The vacuum control valve (20) a first valve seat (21, 21a) having a first valve opening (22, 22a) defining a first opening axis (O) and a first sealing surface extending to surround the first valve opening (22, 22a); a first valve disc (23, 23a) having a first contact surface corresponding to said first sealing surface; Equipped with A drive unit (30) is provided, the drive unit (30) comprising: The first valve disc (23, 23a) comprises at least From an open position in which the first valve disc (23, 23a) and the first valve seat (21, 21a) are in no contact with each other relative to each other, a closed position in which a tight contact is established between the first sealing surface and the first contact surface via an intervening sealing member (25), thereby closing the first valve opening (22, 22a) in a gas-tight manner; and again adjustable from the closed position to the open position. and thus connected to the first valve disc (23, 23a), In a vacuum processing system (1), the first valve seat (21, 21a) is disposed inside the vacuum chamber (10) and divides the vacuum chamber (10) into a main process chamber (11) for processing a substrate and a sub-process chamber (12); the first sealing surface extends in a direction perpendicular to the first opening axis (O) and is directed toward the auxiliary process chamber (12); The first valve disk (23, 23a) is disposed within the auxiliary process chamber (12) so as to be movable and adjustable. A vacuum processing system (1).

2. The vacuum control valve (20) a second valve seat (21 b) having a second valve opening (22 b) defining a second opening axis and a second sealing surface extending circumferentially about the second valve opening (22 b); a second valve disc (23b) having a second contact surface corresponding to said second sealing surface; having the second valve seat (21b) is disposed inside the vacuum chamber (10) and, together with the first valve seat (21, 21a), divides the vacuum chamber into the main process chamber (11) and the auxiliary process chamber (12); the second sealing surface extends perpendicular to the second opening axis and faces toward the auxiliary process chamber (12); the second valve disk (23b) is disposed within the secondary process chamber (12) so as to be adjustable in movement; a full valve opening of the vacuum control valve is formed by at least the first valve opening (22a) which is a first valve partial opening and the second valve opening (22b) which is a second valve partial opening; 2. A vacuum processing system (1) according to claim 1, characterised in that

3. The vacuum control valve (20) a third valve seat (21c) having a third valve opening (22c) defining a third opening axis and a third sealing surface extending circumferentially about the third valve opening (22c); a third valve disc (23c) having a third contact surface corresponding to said third sealing surface; having the third valve seat (21c) is disposed inside the vacuum chamber (10) and, together with the first valve seat (21a) and the second valve seat (21b), divides the vacuum chamber (10) into the main process chamber (11) and the sub-process chamber (12); the third sealing surface extends perpendicular to the third opening axis and faces the secondary process chamber (12); the third valve disk (23c) is disposed within the secondary process chamber (12) so as to be adjustable in movement; the full valve opening is additionally formed by a third valve partial opening (22c), 3. A vacuum processing system (1) according to claim 1 or 2, characterized in that it comprises:

4. The drive unit (30) is connected to the second or third valve disc (23b, 23c), and the connected valve disc (23a to 23c) has at least From the open positions where the valve discs and the valve seats are in a relatively non-contact state with each other, a closed position in which a tight axial contact is established between the sealing surfaces and the contact surfaces via the respective intervening sealing members, thereby closing the respective valve partial openings in a gas-tight manner; and is adjustable again from the closed position to the open position.

3. A vacuum processing system (1) according to claim 2, characterised in that

5. 3. The vacuum processing system (1) according to claim 1 or 2, characterized in that the vacuum control valve (20) has a coupling device which provides a mechanical coupling between the first valve disc (23, 23a) and the second valve disc (23b) and in particular the third valve disc (23c) and is thus coupled to the drive unit (30) such that the valve discs (23, 23a-23c) are movable together and adjustable by the drive unit (30).

6. said drive unit (30) having at least one first drive component and a second drive component, in particular a third drive component, in particular a respective motor; the first drive component is connected to the first valve disc (23a), the second drive component is connected to the second valve disc (23b), and in particular the third drive component is connected to the third valve disc; 3. A vacuum processing system (1) according to claim 1 or 2, characterized in that it comprises:

7. The drive unit (30) and at least the first valve disc (23, 23a) are At least the first of the valve discs (23, 23a) is movable and adjustable along a first adjustment axis (V); and The first adjustment axis (V) extends in a direction intersecting the first opening axis (O), 3. The vacuum processing system (1) according to claim 1 or 2, characterized in that it is constructed and connected.

8. 3. The vacuum processing system (1) according to claim 1 or 2, characterized in that the main process chamber (11) comprises a main internal volume and the secondary process chamber (12) comprises a secondary internal volume, the main internal volume being larger than the secondary internal volume.

9. 3. The vacuum processing system (1) according to claim 1 or 2, characterized in that the vacuum processing system (1) comprises an electrostatic holding device (15), in particular a chuck, arranged in the main process chamber (11).

10. the vacuum control valve (20) has at least the first valve seat (21, 21a) and at least two further valve seats (21b, 21c), the valve seats (21, 21a-21c) defining a first valve opening (22, 22a) and at least two further valve openings (22b, 22c); These valve seats (21, 21a to 21c) are arranged symmetrically around the electrostatic retention device (15). Vacuum processing system (1) according to claim 9, characterized in that

11. 11. The vacuum processing system (1) according to claim 10, characterized in that the valve seats (21, 21a-21c) and / or the valve openings (22, 22a-22c) are formed in the shape of ring segments and are arranged such that each inner or outer arc of the ring-segment valve seats or valve openings lies along a common circle.

12. 3. The vacuum processing system (1) according to claim 1 or 2, characterized in that the vacuum processing system (1) has a control unit, in particular a closed-loop control unit, and the drive unit is controllable with respect to a control signal provided by the control unit, in particular a control variable for closed-loop control.

13. 13. The vacuum processing system (1) according to claim 12, characterized in that each drive component of the drive unit is individually controllable by said control signal.

14. 13. The vacuum processing system (1) according to claim 12, characterized in that the control unit has a flow functionality set in such a way that, when executed, at least one of the valve discs (23, 23a-23c) connected to the drive unit (30) is adjusted to move to an intermediate position between the open position and the closed position.

15. 15. The vacuum processing system (1) according to claim 14, characterized in that the at least one connected valve disc (23, 23a-23c) is linearly adjustable along an adjustment axis (V), and a distance between a contact surface of the valve disc and a corresponding sealing surface in the intermediate position is smaller than in the open position and larger than in the closed position.

16. The vacuum control valve (20) comprises at least The first and second valve seats (21, 21a to 21c); the first and second valve discs (23, 23a-23c); the first drive component coupled to the first valve disc and the second drive component coupled to the second valve disc; having the flow functionality is such that the valve discs (23, 23a-23c) are individually positionable between respective open and closed positions in relation to flow information; Vacuum processing system (1) according to claim 14, characterized in that

17. The flow information includes the following information: mass or volumetric flow of fluid through the main process chamber and / or the secondary process chamber; the flow rate of fluids in the main process chamber and / or the secondary process chamber; a flow velocity distribution with respect to an internal volume cross-section for the main process chamber and / or the secondary process chamber; a pressure difference between the main process chamber and the secondary process chamber; a fluid input into the main process chamber; a fluid outflow from said secondary process chamber; 17. The vacuum processing system (1) according to claim 16, characterized in that it comprises at least one of the following:

18. 17. The vacuum processing system (1) of claim 16, wherein the valve discs (23, 23a-23c) are positionable to provide symmetrical fluid flow through the main process chamber (11) in relation to the flow information.

19. 17. The vacuum processing system (1) of claim 16, wherein the positioning of the valve disks (23, 23a-23c) is individually and dynamically adjustable to provide continuous, closed-loop control of fluid flow through the main process chamber (11).

20. 17. The vacuum treatment system (1) according to claim 16, characterized in that the defined flow characteristic is adjustable and / or closed-loop controllable by the vacuum control valve (20), in particular by means of at least two valve partial openings (22a-22c), in particular in that the flow characteristic is asymmetrically adjustable by the vacuum control valve with respect to a central axis of the vacuum control valve (20), the central axis running through a valve center point.

21. 17. The vacuum processing system (1) of claim 16, characterized in that, when there is a non-homogeneous fluid flow through the main process chamber (11), by implementing the flow functionality, a symmetrical fluid flow can be adjusted.

22. 17. The vacuum processing system (1) according to claim 16, characterized in that the vacuum processing system (1) comprises at least one sensor unit, which is configured such that the flow information is detectable by the sensor unit.

23. 3. The vacuum processing system (1) according to claim 1 or 2, characterized in that the flow path connects the main process chamber (11) and the secondary process chamber (12), and the main process chamber (11) can be separated from the secondary process chamber (12) in a gas-tight manner by the vacuum control valve (20).

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