Pin Lifting Device

Abstract

A pin lifting device (1) for lowering a substrate (2) onto a substrate carrier (15) and lifting the substrate (2) from the substrate carrier (15) in a process chamber, particularly a vacuum process chamber, the pin lifting device (1) having at least one lifting pin holder (4) and at least one lifting drive (5) for reciprocating the lifting pin holder (4) along a linear lifting motion path (7) together with lifting pins (6) arranged on the lifting pin holder, the lifting pin holder (4) being supported in the lifting drive (5) by a compensating support (8), which allows relative movement between the lifting drive (5) and the lifting pin holder (4) in at least one direction (9) perpendicular to the linear lifting motion path (7).

Description

[Technical Field]

[0001] The present invention relates to a pin lifting device for lowering a substrate onto a substrate carrier and lifting the substrate from the substrate carrier in a process chamber, particularly a vacuum process chamber, the pin lifting device having at least one lifting pin holder and at least one lifting drive device for reciprocating the lifting pin holder along a linear lifting motion trajectory together with lifting pins arranged on the lifting pin holder.

[0002] In the prior art, substrates such as wafers are often coated, mounted, and / or otherwise processed in process chambers, particularly vacuum process chambers. For this purpose, the substrates are supported on a substrate carrier during processing. The introduction of the substrate into the process chamber and the removal of the substrate from the process chamber are also usually performed by a suitable robot arm or the like through a corresponding chamber opening of the process chamber. It is also known for the robot arm to place the substrate in the process chamber onto the lifting pins of a general-purpose pin lifting device. The substrate is then lowered or placed onto the substrate carrier by the pin lifting device. After the processing step is performed, the substrate is lifted again by the pin lifting device using the respective lifting pins, so that it can then be removed again from the process chamber by the robot arm or the like.

[0003] Pin lifting devices of the type mentioned at the outset are known, for example, from DE 102018009871 A1 and EP 3450809 A1.

[0004] DE 10 2018 009 871 A1 concerns the question of how the operational readiness and wear monitoring of pin lifting devices can be improved. For this purpose, the document proposes the use of various sensors.

[0005] EP 3450809 A1 concerns how to mount lifting pins as wear material in a lifting pin holder in a replaceable manner as simply as possible. To this end, the document proposes a special type of lifting pin connection.

[0006] In the prior art, it is known to support and guide lifting pins driven by a pin lifting device in a penetration of a substrate carrier. The opening diameter of the penetration through the substrate carrier is very precisely adapted to the lifting pin. As a result, the pin lifting device must be very precisely adjusted during assembly, which results in a corresponding increase in the effort during assembly and maintenance work.

[0007] The object of the present invention is to propose an improvement which makes it possible to reduce the effort required when assembling a pin lifting device.

[0008] To solve this problem, the present invention proposes a pin lifting device according to claim 1.

[0009] Therefore, according to the present invention, it is provided that the lifting pin holder is supported in the lifting drive by a compensating support, which allows relative movement between the lifting drive and the lifting pin holder in at least one direction perpendicular to the linear lifting movement path.

[0010] The compensating support according to the present invention between the lifting pin holder and the lifting drive allows relative movement between the lifting pin holder and the lifting drive in at least one direction perpendicular to the linear lifting movement path, providing a tolerance range that also simplifies the assembly and maintenance of the pin lifting device. In other words, any misalignment between the penetrations in the substrate carrier and the lifting pin holder is automatically compensated for in a simple manner via the compensating support, so that less rigorous work is required when assembling the respective pin lifting device. Furthermore, the tolerance range provided by the compensating support according to the present invention also allows compensation for temperature-induced geometric changes in the pin lifting device and / or the substrate carrier and / or the process chamber, for example, during operation of the process chamber.

[0011] It is particularly preferred that the compensating bearing allows relative movement between the lifting drive and the lifting pin holder in a plane that is arranged perpendicular to the linear lifting movement path. That is, the relative movement possibilities provided by the compensating bearing between the lifting drive and the lifting pin holder are not only possible in individual directions perpendicular to the linear lifting movement path, but also in all directions perpendicular to the linear lifting movement path in the above-mentioned plane. Thus, relative movement possibilities in all directions between the lifting drive and the lifting pin holder in this plane are possible.

[0012] In principle, the lifting pins can be fixedly mounted in the lifting pin holder, so that they are part of the pin lifting device. However, it is usually advantageous to provide the lifting pins as replaceable wear parts. In this case, the lifting pins are not necessarily part of the pin lifting device. Rather, it is provided that the lifting pins can be arranged or attached to the lifting pin holder in a replaceable manner. For this purpose, corresponding lifting pin connections are known in the prior art, for example, from EP 3450809 A1, which was already mentioned at the beginning. This lifting pin connection can be used in the implementation of the present invention to detachably and / or replaceably attach the lifting pins to the lifting pin holder.

[0013] The pin lifting device according to the present invention may also be referred to as a pin lifter or a ring lifter. Substrates to be processed in a process chamber are often referred to as wafers in the prior art. Substrates may also be referred to as carriers, supports, carrier plates, layer carriers, etc. Various processing steps may be performed on each substrate in the process chamber. Examples include mounting specific components on the substrate, coating the substrate, etching the substrate, etc. The substrate carrier of a process chamber may also be referred to as a chuck, as in the prior art.

[0014] The lifting drive of the pin lifting device can be a variety of linear drives. For example, pneumatic or hydraulic piston-cylinder units are conceivable. Other linear drives can also be used as the lifting drive. It is particularly advantageous if the lifting drive has an electric motor and a spindle drive that is driven by the electric motor and causes the lifting pin holder and the lifting pins arranged therein to move back and forth along a linear lifting movement path.

[0015] It is usually advisable to monitor and preferably adjust the pressure exerted by the pin lifting device on the substrate via the lifting pins, the positioning of the lifting pins, and / or the movement speed during lifting and lowering of the substrate. For this purpose, sensor devices such as those known from the prior art mentioned at the beginning can basically be used. Simple monitoring of the force exerted by the pin lifting device on the substrate via the lifting pins can be achieved by monitoring the current consumption of the electric motor of the lifting drive, if an electric motor is used in the lifting drive, and, if necessary, adjusting (closed-loop control) or controlling (open-loop control) accordingly. This is known per se in the prior art and does not need to be further explained here.

[0016] In any case, it is advantageous if the relative movement between the lifting drive and the lifting pin holder, enabled by the compensating bearing, is designed to be as smooth as possible with low friction. To this end, a preferred embodiment of the present invention proposes that the compensating bearing has at least one bearing with rolling elements or at least one sliding bearing, on which the lifting pin holder is supported so as to be movable relative to the lifting drive in at least one direction perpendicular to the linear lifting movement path, preferably in a plane perpendicular to the linear lifting movement path. In this regard, it is particularly advantageous if the compensating bearing has at least two bearings with rolling elements and / or at least two sliding bearings, and the lifting pin holder is supported between the bearings with rolling elements and / or the sliding bearings. As the bearings with rolling elements, so-called ball cages with balls are particularly preferably used. Ball cages are known per se and are cages or carrier plates in which a number of balls are rotatably arranged. Ball cages with such balls have the advantage, on the one hand, of smooth movement with very little friction. On the other hand, they allow uniform relative movement between the lifting drive and the lifting pin holder, which is associated with equally low friction, in all directions perpendicular to the lifting movement path.

[0017] The tolerance compensation made possible by the compensating bearing is advantageously in the range of 0 mm to 6 mm, preferably 0 mm to 3 mm. It is therefore preferably provided that the compensating bearing makes possible a relative movement between the lifting pin holder and the lifting drive in at least one direction perpendicular to the linear lifting movement path in the range of 0 mm to 6 mm, preferably 0 mm to 3 mm, or that the compensating bearing makes possible a relative movement between the lifting pin holder and the lifting drive in a plane arranged perpendicular to the linear lifting movement path in the range of 0 mm to 6 mm, preferably 0 mm to 3 mm.

[0018] In order to configure the compensator bearing as free as possible from play in a direction parallel to the lifting movement path, a preferred embodiment of the present invention provides that the pin lifting device has a preloading device for elastically preloading the lifting pin holder in the compensator bearing in a direction coaxial or parallel to the lifting movement path. It is also preferably provided that the lifting drive has a lifting drive movement axis that is offset parallel to the lifting pins arranged in the lifting pin holder. However, in the case of the pin lifting device according to the present invention, it may alternatively be provided that the lifting drive axis and the lifting pins arranged in the lifting pin holder are arranged coaxially with each other.

[0019] The pin lifting device according to the present invention can be installed or used in various types of process chambers. However, it is particularly suitable for use in so-called vacuum process chambers. A "vacuum process chamber" is defined as a chamber in which a process is carried out and operating conditions are established, with a pressure of 0.001 mbar (millibar) or less, or 0.1 Pascal. Generally speaking, a vacuum process chamber can also be called a negative pressure process chamber if it is designed for a pressure lower than standard pressure, i.e., less than 1 bar.

[0020] Further features and details of preferred embodiments of the invention are explained below by way of example in the form of implementation variations according to the invention. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a schematic exterior view of a vacuum process chamber equipped with a pin lifting device according to the present invention; [Figure 2] FIG. 2 is a longitudinal cross-sectional view taken along the cutting line AA. [Figure 3] FIG. 2 is an exterior view again of the vacuum process chamber shown in FIG. 1. [Figure 4] FIG. 4 is a vertical cross-sectional view taken along the cutting line BB shown in FIG. [Figure 5] 1 is a side view of a first embodiment of a pin lifting device according to the present invention in a retracted position; FIG. [Figure 6] 6 is a longitudinal cross-sectional view of the pin lifting device taken along the section line CC shown in FIG. 5. [Figure 7] FIG. 7 is a side view of the pin lifting device shown in FIGS. 5 and 6 in a deployed position. [Figure 8] FIG. 8 is a longitudinal cross-sectional view taken along the cutting line DD shown in FIG. 7. [Figure 9] FIG. 2 is an enlarged view of the pin lifting device of the first embodiment, showing the parts important to the present invention. [Figure 10] FIG. 10 is an exploded view of the components shown in FIG. 9. [Figure 11] FIG. 10 is a top view showing the portion of the pin lifting device of the first embodiment shown in FIG. 9. [Figure 12] FIG. 1 is a side view showing a second embodiment of a pin lifting device according to the present invention. [Figure 13] FIG. 13 is a longitudinal cross-sectional view of the variation shown in FIG. [Figure 14] FIG. 14 is an enlarged view of an area F shown in FIG.

[0022] 1 and 3 show the process chamber 3 diagrammatically from the outside, with a view into the chamber through a chamber opening 16, in which a substrate 2 supported on lifting pins 6 of a pin lifting device 1 is visible. In the operating position shown in FIG. 1, the substrate 2 is lifted from a substrate carrier 15 by the lifting pins 6 of the pin lifting device 1. In this case, the substrate 2 rests on the lifting pins 6. In the operating position shown in FIG. 3, the lifting pins 6 of the pin lifting device have been advanced along a lifting movement path 7 to such an extent that the substrate 2 is positioned on the substrate carrier 15, as prescribed for processing the substrate 2 in the process chamber 3.

[0023] FIG. 2 shows a longitudinal section along the section line AA shown in FIG. 1 , and FIG. 4 shows a longitudinal section along the section line BB shown in FIG. 3 . Various additional components of such a process chamber 3, as known in the prior art, are not important to the present invention and are therefore not shown here for simplicity. These may be, for example, a pump system for evacuating the process chamber 3. A valve for closing the chamber opening 16 is also not shown. The introduction and removal of the substrate 2 into and from the process chamber 3 through the chamber opening 16 is known per se in the prior art and can be carried out as shown diagrammatically in FIG. 1 of DE 10 2018 009 871 A1. A robot arm, not shown here, can place the substrate 2 on the lifting pins 6 in the exit position shown in FIGS. 1 and 2 and remove it from the lifting pins 6 again. The lowering of the substrates 2 onto the substrate carrier 15 and the lifting of the substrates 2 from the substrate carrier 15 are performed by the pin lifting device 1 according to the invention and by lifting pins 6 arranged in the respective lifting pin holders 4 of the pin lifting device 1. The lifting pins 6 are movably supported through penetrations 17 provided in the substrate carrier 15, as can be seen in Figures 2 and 4. The penetrations 17, which may also be referred to as penetration openings, are usually adapted very precisely to the thickness of the lifting pins 6, which means that in the prior art, relatively narrow tolerances have to be taken into account when assembling the pin lifting device 1, which results in corresponding assembly efforts.

[0024] To overcome this drawback of the prior art, the pin lifting device 1 according to the present invention includes at least one compensating support 8, by which the lifting pin holder 4 is supported on the lifting drive 5, and which allows relative movement between the lifting drive 5 and the lifting pin holder 4 in at least one direction 9 perpendicular to the linear lifting motion path 7. The pin lifting device 1 according to the present invention used in this first embodiment is illustrated in FIGS. 5 to 8. FIGS. 5 and 6 show the operating position in which the lifting pin holder 4, together with the lifting pins 6 disposed therein, has been returned to a position in which the substrate 2 is located on the substrate carrier 15. FIGS. 7 and 8 show the corresponding exit position along the lifting motion path 7, in which the lifting pins 6 lift the substrate 2 from the substrate carrier 15, as illustrated in FIGS. 1 and 2.

[0025] FIG. 6 shows a longitudinal section of a first embodiment of a pin lifting device 1 according to the present invention along the section line CC shown in FIG. 5, and FIG. 8 shows a corresponding longitudinal section along the section line DD shown in FIG. 7.

[0026] As already explained at the beginning, there are different variations for the lifting drive 5 used in the pin lifting device 1 according to the invention in order to realize the linear movement along the lifting movement path 7 by the lifting drive 5. In the embodiment shown, the lifting drive 5 has an electric motor 13 and a spindle drive 14. The electric motor 13 rotates a spindle 20 of the spindle drive 14 about a longitudinal axis that is arranged coaxially with the lifting drive movement axis 12. The external thread of the spindle 20 engages in an internal thread of a spindle nut 21 of the spindle drive 14 in a manner known per se. The spindle nut 21 itself is fixedly positioned on the lifting drive rod 22 of the spindle drive 14, so that rotation of the spindle 20 by the electric motor 13 in the respective rotational direction results in the movement in and out of the lifting drive rod 22, and thus in a corresponding movement of the lifting pin 6 arranged in the lifting pin holder 4 along the linear lifting movement path 7.

[0027] The compensating bearing 8, which is essential for the invention, is housed in a bearing casing 23 in this embodiment. The bearing casing 23 is attached to the lifting drive rod 22 and thus to the lifting drive 5 by means of mounting screws 19. The lifting pin holder 4 is supported by the compensating bearing 8 so as to be movable relative to the bearing casing 23 and thus also relative to the lifting drive 5 in a direction 9 perpendicular to the lifting movement path 7. For a detailed explanation of how the compensating bearing 8 is configured in this first embodiment, reference is made to Figures 9 and 10.

[0028] Figure 9 shows the support casing 23 and the components of the pin lifting device 1 arranged in this support casing 23 in an assembled state, and Figure 10 shows these components in an exploded view.

[0029] In a first exemplary embodiment, the compensating bearing 8 is in the form of a ball cage with balls and comprises two bearings 10 with rolling elements. The lifting pin holder 4 is located between these two bearings 10 with rolling elements. The bearings 10 with rolling elements function to allow the lifting pin holder 4 to move relative to the lifting drive 5 in a direction 9 perpendicular to the lifting movement path 7 almost without friction, or at least with only very low friction. A receiving portion for the lifting pin 6 is located in the lifting pin holder 4. In this exemplary embodiment, this receiving portion is configured as a lifting pin connection 18, which is known per se. In this lifting pin connection 18, the lifting pin 6 can be attached to the lifting pin holder 4 in an exchangeable manner. The lifting pin connection 18 can be configured, for example, as described in EP 3 450 809 A1. Naturally, other configurations of the lifting pin connection 18 are also conceivable. The lifting pins 6 may be fixedly attached to the lifting pin holder 4 if they do not need to be considered wear members.

[0030] Instead of the bearing 10 with rolling elements configured in the form of a ball cage with balls, another bearing 10 with rolling elements or a sliding bearing can also be used, but a corresponding ball cage with balls or a bearing 10 with rolling elements provides particularly low friction values.

[0031] In order to preload the lifting pin holder 4 and the bearing 10 with the rolling elements or the entire compensating bearing 8 without play in a direction parallel to the lifting movement path 7, a preload device 11 is provided in this embodiment. The preload device 11 comprises a preload screw 24, a preload disk 26, a preload cup 28 and a disc spring 27 arranged between the preload disk 26 and the preload cup 28. The preload screw 24, which is screwed into a corresponding screw receptacle 29 in the bearing casing 23, makes it possible to adjust the preload applied by the preload device 11 to the compensating bearing 8.

[0032] The mounting screw 19 already mentioned above and the washer 25 arranged between this mounting screw 19 and the bearing casing 23 are likewise shown in Figures 9 and 10. Also shown are the direction 9 perpendicular to the lifting movement path 7, in which the compensating bearing 8 allows a relative movement between the lifting pin holder 4 according to the invention and the lifting drive 5.

[0033] In the preferred configuration shown, the movement possibility provided by the compensating bearing 8 is not only the possibility of movement in individual directions 9 perpendicular to the lifting movement path 7, but also the possibility of relative movement between the lifting pin holder 4 and the lifting drive 5 or the bearing casing 23 in all directions in a plane perpendicular to the lifting movement path 7. This is illustrated in Figure 11 by the different directions 9 shown by way of example in the aforementioned plane. The section line EE shown in Figure 11 indicates the section along which Figures 9 and 10 are cut.

[0034] In the first embodiment of the pin lifting device 1 shown in FIGS. 1 to 11 , the lifting drive movement axis 12 of the lifting drive 5 is arranged parallel to and offset from the lifting pins 6 arranged in the lifting pin holder 4. This does not necessarily have to be the case, as is specifically shown for the second embodiment of the pin lifting device 1 according to the invention shown in FIGS. 12 to 14 and described below. This second embodiment of the pin lifting device 1 according to the invention can be used in a process chamber 3 in a similar manner as shown in FIGS. 1 to 4 for the first embodiment of the pin lifting device 1 according to the invention. In this second embodiment, the lifting pins 6 or the lifting movement track 7 are arranged coaxially with the lifting drive movement axis 12. The lifting drive 5 and the lifting pin coupling 18 are configured substantially similarly to the first embodiment, and therefore will not be described further.

[0035] FIG. 14 shows an enlarged view of a partial region F of the cross section of FIG. 13. Here, a compensating bearing 18 is provided, in which the lifting pin holder 4 is supported between two bearings 10 with rolling elements in the form of ball cages with balls. This compensating bearing 8 allows for the relative movement of the lifting pin holder 4 with respect to the lifting drive 5 in a direction 9 perpendicular to the lifting movement path 7. This again allows for tolerance compensation in all directions within a corresponding plane perpendicular to the lifting movement path 7. In this embodiment, the preload is again provided by a preload device 11, which likewise consists of a preload plate 26, a preload cup 28, and a disc spring 27 arranged between the preload plate 26 and the preload cup 28. This preload device 11 also provides a corresponding elastic preload to the compensating bearing 8 in a direction parallel to the lifting movement path 7, and thus a corresponding play-free position in this direction. [Explanation of symbols]

[0036] 1 Pin lifting device 2 boards 3. Process chamber 4 Lifting Pin Holder 5 Lifting drive unit 6 lifting pins 7. Lifting movement trajectory 8 Compensation support 9 directions 10. Bearing with rolling elements 11 Preload device 12 Lifting drive motion axis 13 Electric motor 14 Spindle drive unit 15 Substrate Carrier 16 Chamber opening 17 Penetration 18 Lifting pin joint 19 Mounting screws 20 spindles 21 Spindle nut 22 Lifting drive rod 23 Bearing casing 24 Preload screw 25 washer 26 Preload tray 27 Disc spring 28 Preload Cup 29 Screw holder

Claims

1. A pin lifting device (1) for lowering a substrate (2) onto a substrate carrier (15) in a process chamber and lifting the substrate (2) from the substrate carrier (15), the pin lifting device (1) having at least one lifting pin holder (4) and at least one lifting drive device (5) for reciprocating the lifting pin holder (4) along a linear lifting motion path (7) together with lifting pins (6) arranged on the lifting pin holder, the lifting pin holder (4) is supported in the lifting drive (5) by a compensating bearing (8), which allows a relative movement between the lifting drive (5) and the lifting pin holder (4) in at least one direction (9) perpendicular to the linear lifting movement path (7); the pin lifting device (1) comprises a preloading device (11) for elastically preloading the lifting pin holder (4) in the compensating bearing (8) in a direction coaxial or parallel to the lifting movement path (7), The pin lifting device (1) is characterized in that the preload device (11) comprises a preload plate (26), a preload cup (28), and a disc spring (27) disposed between the preload plate (26) and the preload cup (28).

2. 2. The pin lifting device (1) according to claim 1, wherein the compensating support (8) allows relative movement between the lifting drive (5) and the lifting pin holder (4) in a plane arranged perpendicular to the linear lifting movement path (7).

3. 3. The pin lifting device (1) according to claim 1 or 2, wherein the compensating bearing (8) has at least one bearing (10) with rolling elements or at least one sliding bearing, on which the lifting pin holder (4) is supported so as to be movable relative to the lifting drive device (5) in at least one direction perpendicular to the linear lifting movement path (7).

4. A pin lifting device (1) as described in claim 3, wherein the lifting pin holder (4) is supported on the support body (10) so as to be movable relative to the lifting drive device (5) within a plane arranged perpendicular to the linear lifting motion path (7).

5. 5. The pin lifting device (1) according to claim 3 or 4, wherein the compensation bearing (8) has at least two bearings (10) with rolling elements and / or sliding bearings, and the lifting pin holder (4) is supported between the bearings (10) with rolling elements and / or sliding bearings.

6. The pin lifting device (1) according to any one of claims 3 to 5, wherein the support body (10) with the rolling elements is a ball cage with balls, or the plurality of support bodies (10) with a plurality of rolling elements is a plurality of ball cages with a plurality of balls.

7. 7. The pin lifting device (1) according to claim 1, wherein the compensating support (8) allows a relative movement between the lifting pin holder (4) and the lifting drive device (5) in at least one direction (9) perpendicular to the linear lifting movement path (7) in a range between 0 mm and 6 mm.

8. A pin lifting device (1) as described in claim 7, wherein the compensating support (8) enables relative movement between the lifting pin holder (4) and the lifting drive device (5) in at least one direction (9) perpendicular to the linear lifting movement path (7) in a range between 0 mm and 3 mm.

9. 7. The pin lifting device (1) according to claim 2, wherein the compensating support (8) allows a relative movement between the lifting pin holder (4) and the lifting drive (5) in a plane arranged perpendicular to the linear lifting movement path (7) in a range between 0 mm and 6 mm.

10. A pin lifting device (1) as described in claim 9, wherein the compensating support (8) enables relative movement between the lifting pin holder (4) and the lifting drive device (5) in a plane arranged perpendicular to the linear lifting movement path (7) in a range between 0 mm and 3 mm.

11. The pin lifting device (1) according to any one of the preceding claims, wherein the process chamber is a vacuum process chamber.

12. 12. A pin lifting device (1) according to claim 1, wherein the lifting drive (5) has a lifting drive movement axis (12) that is arranged parallel to and offset from the lifting pin (6) arranged in the lifting pin holder (4).

13. 13. The pin lifting device (1) according to claim 1, wherein the lifting drive (5) comprises an electric motor (13) and a spindle drive (14) driven by the electric motor (13).

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