Gas inlet valve for a vacuum process chamber - Patents.com

Abstract

The invention relates to a gas inlet valve (1) for the controlled inlet of a process gas into a vacuum process chamber, the gas inlet valve comprising: a gas-conducting unit (2) with a gas inlet (21), a gas outlet (22) and an internal volume (23), the internal volume (23) having free access to the gas inlet and the gas outlet, the gas-conducting unit having a sealing surface (24) within the internal volume; and a regulating device (3) with an adjusting unit (31), the adjusting unit projecting into the internal volume and adjustably supported in the regulating device outside the gas-conducting unit, the adjusting unit having a disk (32) arranged within the internal volume, the disk (32) being movable by the regulating device (3) into a closed position, the closed position being such that the disk (32) is movable into a closed position by the regulating device (3). a regulating device (3) in which a disc rests on a sealing surface, thereby blocking gas flow, and which is movable by the regulating device to an open position, in which the disc is spaced from the sealing surface, thereby allowing gas flow; two flexible sealing elements (41, 42) attached to the gas flow unit and the regulating unit, respectively, thereby sealing an internal volume; and a position determining unit (5) arranged on or within the regulating device and adapted to determine the position of a part of the regulating unit that has a fixed positional relationship with the disc.

Description

[Technical field]

[0001] The present invention relates to a gas inlet valve for admitting process gases into a vacuum process chamber. [Background technology]

[0002] Such vacuum process chambers are used for integrated circuit (IC) manufacturing, semiconductor manufacturing, flat panel manufacturing or substrate manufacturing. In this case, the vacuum chamber is pumped with process gases after evacuation for at least some of the process steps. The manufacturing has to take place in a protected atmosphere and as far as possible without the presence of contaminating particles. The evacuation is in this case carried out by means of a vacuum valve, which connects the vacuum process chamber to a vacuum pump and whose construction and technical requirements differ from those of a gas inlet valve.

[0003] Furthermore, such a vacuum chamber has at least one or two vacuum chamber openings, through which the elements to be processed can be introduced into and / or removed from the vacuum chamber. For example, in manufacturing facilities for semiconductor wafers or liquid crystal substrates, highly sensitive semiconductor or liquid crystal elements pass successively through several vacuum process chambers, in which the elements are each processed by one processing device.

[0004] The element can be placed, for example by means of a robot, on the run-out support pins of a lift system, which can then be lowered to place it on a support, for example on a potential plate (chuck). Afterwards, the robot arm, which typically supports the element, runs out of the chamber. The pins can be lowered after placing the element and are then located separate from this element, i.e. no contact between the pins and the element occurs. After removal of the robot arm and closing of the chamber, the chamber is usually evacuated and then filled with process gas. Processing of the element can then start.

[0005] Gas inlet valves are designed in particular for a defined control or regulation of the gas flow and are located, for example, in a pipe system between a vacuum process chamber (or a transfer chamber) and a gas source, atmosphere or another vacuum process chamber. The opening cross section of such gas inlet valves is usually smaller than the opening cross section of a vacuum valve.

[0006] Gas inlet valves are also called regulating valves, since, depending on the field of use, they can be used not only for completely opening and closing an opening, but also for controlling or regulating the flow rate by continuously adjusting the opening cross section between an open position and a gas-tight closed position.

[0007] During the inflow of process gases into the chamber, small fluidic effects in the chamber and fast, precisely controllable filling are important. Summary of the Invention [Problem to be solved by the invention]

[0008] It is therefore an object of the present invention to provide an improved gas inlet valve for a vacuum process chamber, in particular a gas inlet valve according to the present invention which allows for a fast, precise and adjustable injection of process gas into an evacuated vacuum process chamber. [Means for solving the problem]

[0009] The invention relates to a gas inlet valve for the controlled inlet of a process gas into a vacuum process chamber, the gas inlet valve comprising a gas flow unit with a gas inlet, a gas outlet and an internal volume, the internal volume having free access to the gas inlet and the gas outlet, the gas flow unit having a sealing surface in the internal volume, and an adjustment device comprising an adjustment unit, the adjustment unit protruding into the internal volume and being adjustably supported in the adjustment device outside the gas flow unit, the adjustment unit having a disk arranged in the internal volume, the disk being movable by the adjustment device into a closed position, in which the disk is sealed. The present invention relates to a gas inlet valve having a disk that is placed on a sealing surface, thereby blocking gas flow, and the disk is movable by the adjustment device to an open position, in which the disk is spaced from the sealing surface, thereby allowing gas flow, a first flexible sealing element that is attached to the gas flow unit and the adjustment unit, and seals the adjustment device from the internal volume, and a position determination unit that is arranged on or within the adjustment unit and is adjusted to determine the position of a part of the adjustment unit that has a fixed positional relationship to the disk.

[0010] In one embodiment, the gas inlet valve may have a second flexible sealing element, the first flexible sealing element and the second flexible sealing element being attached to the gas flow unit and the regulating unit respectively, thereby embodying two flexible sealing elements sealing the interior volume.

[0011] The invention further relates to a gas inlet valve for the controlled inlet of a process gas into a vacuum process chamber, the gas inlet valve comprising a gas flow unit with a gas inlet, a gas outlet and an internal volume, the internal volume having free access to the gas inlet and the gas outlet, the gas flow unit having a sealing surface in the internal volume, and an adjustment device comprising an adjustment unit, the adjustment unit protruding into the internal volume and being adjustably supported in the adjustment device outside the gas flow unit, the adjustment unit having a disk arranged in the internal volume, the disk being movable by the adjustment device into a closed position, in which the disk is The invention also relates to a gas inlet valve having an adjusting device, the adjusting device being disposed on the sealing surface, thereby blocking gas flow, the disk being movable by the adjusting device to an open position, in which the disk is spaced from the sealing surface, thereby allowing gas flow, two flexible sealing elements attached to the gas flow unit and the adjusting unit, respectively, thereby sealing the internal volume, and a position determining unit, the position determining unit being arranged on or within the adjusting device and adapted to determine the position of a part of the adjusting unit having a fixed positional relationship to the disk.

[0012] According to one embodiment, the first flexible sealing element and / or the second flexible sealing element may be attached to the disc and to the gas flow unit.

[0013] In one embodiment, one or both of the sealing elements are formed as diaphragms, in particular as metal diaphragms. In particular, at least one of the sealing elements and the surface of the disk facing the respective sealing element have similar dimensions, in particular exactly the same pressure acting area, so that at least a substantial pressure cancellation is achieved, which makes the movement of the disk independent of the existing pressure, and thus the valve can be adjusted quickly.

[0014] In the closed position, the disk is pressed against the sealing surface, in particular by a preload, which is applied at least partially from at least one of the sealing elements and / or at least partially from a preload device arranged outside the internal volume. In particular, at least one of the sealing elements therefore has a spring stiffness and can act against the existing pressure forces by the preload. If the preload is applied at least partially from a preload device, the preload device is included in the adjustment device. The abovementioned active areas and / or spring stiffnesses of the spring elements can be adapted to one another so that a preload bias is generated, which advantageously acts on the reaction time of the valve (for example, if only opening or only closing must be possible quickly).

[0015] The disc and / or sealing surface may have a sealing ring that is compressed in the closed position due to a preload to ensure that the gas inlet is gas-tightly separated from the gas outlet.

[0016] The two sealing elements can be preloaded relative to one another, so that when adjusting the adjustment unit, no or only relatively small resistance forces are exerted by the sealing elements.

[0017] The sealing surface, the disc and the sealing element have in particular a circular cross section, the internal volume being at least partially cylindrical and the sealing surface being formed by a step in the internal volume.

[0018] The cylindrical shape of the internal volume is formed in particular by the gas flow unit as the peripheral surface and the sealing element as the base surface, and the gas inlet and the gas outlet achieve free access to the internal volume via the peripheral surface, which means that the gas inlet and the gas outlet, respectively, pass through the peripheral surface.

[0019] The adjustment device may be electrically or pneumatically operated.

[0020] In particular, in the closed position the disc divides the internal volume into a first partial internal volume and a second partial internal volume, the gas inlet having free access to the first partial volume and the gas outlet having free access to the second partial volume.

[0021] The gas outlet in particular has free access to the vacuum process chamber, and the gas inlet in particular has free access to the gas source.

[0022] Other advantages of the present invention will become apparent from the detailed description and drawings. [Brief description of the drawings]

[0023] [Figure 1] FIG. 2 is a perspective view of one embodiment of a gas inlet valve. [Diagram 2] FIG. 2 is a cross-sectional view showing the gas inlet valve shown in FIG. [Diagram 3] 2 is another cross-sectional view showing the gas inlet valve shown in FIG. 1. [Figure 4] FIG. 13 is a detailed view showing the internal volume of the gas inlet valve. [Figure 5a] FIG. 1 illustrates another embodiment of the present invention. [Figure 5b] FIG. 1 illustrates another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] 1 to 3 show an embodiment of a gas inlet valve 1 comprising a gas flow unit 2 having a gas inlet 21, a gas outlet 22 and an internal volume 23. The internal volume 23 has free access to the gas inlet 21 and the gas outlet 22, and the gas flow unit has a sealing surface 24 within the internal volume.

[0025] The adjustment device 3 comprises an adjustment unit 31 and a disk 32. The adjustment unit 31 projects into the internal volume 23 and is adjustably supported in the adjustment device 3 outside the gas flow unit 2. The disk is arranged in the internal volume 23 and can be moved by the adjustment device 3 into a closed position, in which the disk 32 rests on the sealing surface 24, thereby preventing gas flow. The adjustment device 3 can further move the disk into an open position, in which the disk 32 is spaced away from the sealing surface 24, thereby allowing gas flow.

[0026] The gas inlet valve 1 further comprises two flexible sealing elements 41 and 42, which in the illustrated example are configured as diaphragms, which are attached to the gas flow unit 2 and to the regulating unit 31 respectively and thereby seal the internal volume 23.

[0027] The position determination unit 5 is arranged on the regulating device 3 and is adapted to determine the position of the upper end of the regulating unit 31. The regulating unit 31 in the illustrated example has several elements which are fixedly connected to one another, so that the position of the measurement (upper end of the regulating unit 31) has a fixed positional relationship to the disk. This allows the position of the disk to be determined at all times without interruption. In other words, the disk 32 is fixedly connected to the regulating unit 31, so that the determination of the position of the regulating unit 31 coincides at the same time with the determination of the position for the disk 32. By means of the particularly permanent or continuous determination of the disk position, an active control (and / or regulation) of the valve and thus of the gas flow can be carried out. Advantageously, a subsequent determination (downstream of the gas outlet) of the actual gas flow rate (as a controlled variable) depending on the current valve control can be omitted.

[0028] 1 shows a gas inlet valve 1 in a perspective view from the outside, in which in the illustrated example a pneumatic device 6 and a control unit 7 are provided, via which the regulating device 3 is controlled. In another embodiment, the regulating device 3 can be actuated, for example, via an electric motor.

[0029] Connections 81, 82 are provided for the gas inlet 21 and the gas outlet 22, respectively, via which lines to a gas source and to a vacuum process chamber can be connected.

[0030] Figure 3 shows a cross-section of the gas inlet valve 1, similar to Figure 2, but from a different angle, so that in Figure 3 the coil springs 91, 92 integrated in the adjustment device 3 are visible. Via a preload on the springs, the disk 32 is pressed against the sealing surface 24 in the closed position. A sealing ring 33 serves for the gas-tight closure. This sealing ring may in particular consist of an elastomer, a thermoplastic, a metal, etc., and may have a shape adapted to the shape of the disk (e.g. an O-ring) and may be vulcanized to the disk.

[0031] The seal ring may be embedded within the disk 32 (as shown in the drawings) or within the seal face 24 (in alternative embodiments).

[0032] Furthermore, the sealing elements 41 and 42 can be clamped against each other, so that no forces acting on the adjustment unit 31 result. However, this minimizes forces acting against the adjustment direction during the process of moving away of the disk 32 from the sealing surface 24, i.e. when the valve is opened. This is due to the fact that when the valve is opened, one of the sealing elements approaches its basic position, while the other sealing element is (further) clamped by the adjustment path. A decrease on one side and an increase on the other side ideally cancel each other out, but at least minimize the resistance that occurs during adjustment. Thus, when the valve is opened or closed, (substantially) only the preload caused by the preload device (springs 91, 92) has to be overcome. In particular, the sealing element is a metal diaphragm.

[0033] Figure 4 shows the gas flow unit 2 in detail and in particular the adjustable disk 32 in the gas flow unit 2 and both flexible sealing elements 41, 42 which in the illustrated embodiment are fastened between the gas flow unit 2 and the adjustment device 3 or between the gas flow unit 2 and the locking member 10. This fastening can be achieved by screw fastening (see 101 and 102 in Figure 3).

[0034] The mounting of the flexible sealing elements 41, 42 in the adjustment unit 31 can likewise be effected by fastening, as shown in Fig. 4. The adjustment unit 31 comprises not only the rod 311 but also the screw 312, the sleeve 313 and the disk 32. The screw 312 is screwed into the rod 311, so that on the one hand the sealing element 41 is fastened between the rod 311 and the disk 32, and on the other hand the sealing element 42 is fastened between the disk 32 and the sleeve 313. The skilled person is aware of numerous other constructional possibilities for connecting the sealing elements to the adjustment unit in such a way that the disk is adjustable in the internal volume 23.

[0035] The internal volume 23, the disk 32, each with a circular cross section, the sealing surface 24, the shaft 311, the sleeve 313, the sealing elements 41 and 42, the sealing ring 33 are shown. In particular, the internal volume 23 is shown as a hollow cylinder. This is not necessarily the case, since these components may also be manufactured with an elliptical, rectangular or any profile. The sealing surface 24 is shown in this example as a step in the first partial volume 231 with free access to the gas inlet 21, which results in a smaller cross section in the first partial volume. In another embodiment, the step of the sealing surface 24 returns again to the cross section that is also present in the second partial volume 232 with free access to the gas outlet 22. The circumferential surface may have a different shape and does not have to be fitted to a hollow cylinder.

[0036] The first partial volume 231 is formed annularly between the circumferential surface of the internal volume 23 and the circumferential surface of the upper axial portion of the disc 32 and is axially bounded by the sealing element 41 and the front disc surface. The second partial volume 232 is formed annularly between the circumferential surface of the internal volume 23 and the circumferential surface of the lower axial portion of the disc 32 and is axially bounded by the sealing element 42 and the rear disc surface.

[0037] The control unit 7 is especially configured to adjust the disk 32 in a defined manner. The closed position (disk 32 pressed against the sealing surface 24) can be achieved purely passively, i.e. by a possibly occurring preload (preload device and / or sealing element), or by a corresponding active adjustment of the adjustment device 3 controlled by the control unit 7. The open position of the disk 32 means that the disk 32 is lifted from the sealing surface 24. How much the disk 32 is lifted can be defined by the adjustment device 3, which is correspondingly controlled by the control unit 7. Besides the defined target values ​​(closed position, open position with a certain distance), the control unit 7 can be adjusted to take a defined travel path of the disk 32. That is, in order to achieve a slow opening process that avoids turbulences, the disk 32 can be lifted from the sealing surface 24 with a very low starting speed, after which a more rapid rising speed can be achieved after a certain interval. In another embodiment, the valve can be opened in a defined "pulsed" manner, so that the process gas can be introduced into the process chamber in a subdivided manner.

[0038] In particular the position determination unit 5 is continuously read out and used as feedback for controlling the adjustment unit 31 by the control unit 7 .

[0039] In such a particular control, it is further always taken into account that at the gas inlet 21 of the gas flow unit 2 a relatively high pressure (due to a connected gas line or gas cylinder) prevails, while at the gas outlet 22 a pressure between 0 bar and the positive pressure of the gas source may prevail.

[0040] The advantage of the gas inlet valve according to the invention is that reserve gas can be collected, so to speak, in the first partial volume to which the gas inlet 21 has free access, and that this reserve gas can be transferred in a fluid-technically advantageous and rapid manner to the second partial volume 232 when the gas inlet valve 1 opens. Moreover, in relation to this fluid-technical advantage, the gas inlet valve according to the invention has a very small constructional size.

[0041] Another advantage resides in the flexible sealing elements, exemplarily shown in this embodiment as diaphragms 41 and 42. Pressure changes occurring when the gas inlet valve 1 is opened or closed can be buffered by these sealing elements, which increases the durability of the entire system.

[0042] Figures 5a and 5b show another embodiment of the invention. Figure 5a shows a gas inlet valve 100 with a regulating device 103, a gas flow unit 102 and a position determination unit 105. This embodiment differs from the embodiments shown in the previous figures in particular by the configuration of the gas flow unit 102 and the sealing by the (only one) diaphragm 141.

[0043] FIG. 5b shows a cross section of the gas flow unit 102. A valve closing body or valve disk 132 is arranged in the internal volume of the valve 100 and is linearly movable by a rod 131 of the adjustment device 103. The valve disk 132 is fixedly connected to the rod 131. The valve 100 is shown in FIG. 5b in an open state, i.e. gas or fluid can flow through the gas inlet 121 via the internal volume to the gas outlet 122 and through the gas outlet 122. In this state, the valve disk 132 is spaced apart from a sealing surface 124 provided on the inside of the gas flow unit 102. In the illustrated configuration, the valve disk 132 has a sealing element 133. However, it is understood that according to alternative embodiments, the sealing element 133 may also be arranged on the sealing surface 124.

[0044] Due to the fixed and particularly rigid connection between the disc 132 and the rod 131, the position of the disc 132 can be determined directly by the position determination unit 105, which can determine the linear position of the rod 131 (as part of the adjustment unit). The position determination unit 105 therefore makes it possible to determine whether the valve is closed or open and how large the possible clearance between the sealing surface 124 and the valve disc 132 or sealing element 133 is, i.e. how large the existing opening cross section and therefore how large the possible volume flow rate through the valve 100 is currently.

[0045] The diaphragm 141, which is configured as a flexible sealing element, provides a flexible sealing of the inner volume for the adjustment device 103. For this purpose, the diaphragm 141 is connected on the one hand to the gas flow unit 102 and on the other hand to the adjustment unit, which in this embodiment is the disk 132 or the rod 131.

[0046] The figures always show the disk 32 or 132 with an upper and lower axial part (hollow shaft section). In another embodiment, the disk 32 or 132 can simply be a plate, in which case the upper and lower parts of the disk 32 or 132 can be replaced by a simple hollow shaft, which is sealed against this plate in the axial direction. Furthermore, the figures always show the disk 32 or 132 opened in the gas flow direction, i.e. adjusted from above to below in the figures. However, in another embodiment, the components involved can be constructed and arranged in such a way that the disk is pressed from above onto the sealing surface for the closed position and moved towards the top for the open position.

[0047] Although the present invention has been described in terms of its preferred embodiments, many other modifications and variations can be made without departing from the spirit and scope of the present invention, and it is therefore contemplated that the appended claims will cover such modifications and variations as fall within the true scope of the present invention.

Claims

1. A gas inlet valve (1,100) for the controlled admission of a process gas into a vacuum process chamber, the gas inlet valve (1,100) comprising: a gas flow unit (2, 102) with a gas inlet (21, 121), a gas outlet (22, 122) and an internal volume (23), said internal volume (23) having free access to said gas inlet (21, 121) and said gas outlet (22, 122), said gas flow unit having a sealing surface (24, 124) in said internal volume (23); an adjusting device (3, 103) with an adjusting unit (31), the adjusting unit (31) protruding into the internal volume (23) and adjustably supported in the adjusting device (3, 103) outside the gas flow unit (2, 102), the adjusting unit (31) having a disk (32, 132) arranged in the internal volume (23), the disk (32, 132) being movable by the adjusting device (3, 103) into a closed position in which the disk (32, 132) rests on the sealing surface (24, 124) thereby preventing gas flow, and the disk being movable by the adjusting device (3, 103) into an open position in which the disk (32, 132) is spaced from the sealing surface (24, 124) thereby allowing gas flow; a first flexible sealing element (41, 141) attached to the gas flow unit (2, 102) and to the adjustment unit (31), sealing the adjustment device (3, 103) from the internal volume (23); a position determining unit (5, 105) arranged on or in said adjustment device (3, 103) and adapted to determine the position of a part of said adjustment unit (31) having a fixed positional relationship with respect to said disk (32, 132); It has A gas inlet valve (1, 100), wherein the first flexible sealing element (41, 141) is formed as a metal diaphragm.

2. 2. The gas inlet valve (1, 100) according to claim 1, further comprising a second flexible sealing element (42), the first flexible sealing element and the second flexible sealing element being attached to the gas flow unit (2, 102) and the regulating unit (31), respectively, thereby embodying two flexible sealing elements (41, 42) which seal the internal volume (23).

3. 3. The gas inlet valve (1, 100) according to claim 1 or 2, wherein the first flexible sealing element (41) and / or the second flexible sealing element (42) are attached to the disk (32, 132) and to the gas flow unit (2, 102).

4. A gas inlet valve (1,100) as described in any one of claims 1 to 3, wherein both sealing elements (41, 42) are formed as metal diaphragms.

5. 5. A gas inlet valve (1,100) according to claim 1, wherein the disk (32,132) is pressed against the sealing surface (24,124) in the closed position by a preload, the preload being applied at least in part from at least one of the sealing elements and / or at least in part from a preload device arranged outside the internal volume.

6. 6. The gas inlet valve (1, 100) according to any one of the preceding claims, wherein the disk (32, 132) and / or the sealing surface (24) comprises a sealing ring which is compressed in the closed position.

7. The gas inlet valve (1, 100) according to any one of claims 1 to 6, wherein the two sealing elements (41, 42) are preloaded relative to one another, so that when the adjustment unit (31) is adjusted, no or only a relatively small resistance force is generated by the sealing elements.

8. 8. The gas inlet valve (1, 100) according to claim 1, wherein the sealing surface (24), the disk (32, 132) and the sealing element (41, 42) have a circular cross-section, the internal volume is at least partially cylindrical, and the sealing surface is formed by a step in the internal volume.

9. A gas inlet valve (1, 100) according to claim 8, wherein the cylindrical shape of the internal volume (23) is formed by the gas flow unit as a peripheral surface and the sealing element as a base surface, and the gas inlet and the gas outlet achieve free access to the internal volume via the peripheral surface.

10. 10. The gas inlet valve (1, 100) according to any one of the preceding claims, wherein the regulating device (3, 103) is electrically or pneumatically operated.

11. 11. A gas inlet valve (1,100) according to claim 1, wherein in the closed position, the disk (32,132) divides the internal volume (23) into a first partial internal volume (231) and a second partial internal volume (232), the gas inlet having free access to the first partial volume and the gas outlet having free access to the second partial volume.

12. 12. The gas inlet valve (1,100) according to any one of claims 1 to 11, wherein the gas outlet has free access to the vacuum process chamber and the gas inlet has free access to a gas source.

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