Devices for holding, positioning and / or moving objects in a vacuum

Abstract

The present invention relates to an apparatus for holding, positioning, and / or moving an object in a vacuum, comprising a base, an end effector with a substrate holder, a linear drive connected to the end effector via a carriage, an optional vertical or lifting drive acting on the base, and a magnetic bearing for the carriage. According to the invention, the linear drive is designed as a fluid-operated or otherwise sealed cylinder with a double-acting piston, the piston being provided with a magnetic arrangement. The carriage has a magnetic ring that engages the periphery of the cylinder at least at its outer distance and surrounds the cylinder without contact.

Description

[Technical Field]

[0001] The present invention relates to a device for holding, positioning and / or moving objects in a vacuum, comprising a base, an end effector with a substrate holder, a linear drive connected to the end effector via a carriage, a vertical or lift drive engaging with the base, and a magnetic bearing for the carriage according to the preamble of claim 1. [Background technology]

[0002] For example, when processing substrates for manufacturing semiconductor components, large substrates are used that must be subjected to various surface treatments.

[0003] For example, coating, exposure and etching processes, and diffusion processes are required.

[0004] Most surface treatment steps must be performed under clean room conditions or in a vacuum.

[0005] Modern semiconductor components require the creation of structures in the nanometer range from substrates, which requires extremely precise feeding and positioning of the substrates.

[0006] Furthermore, the need for the substrate environment to be particle-free places high demands on the corresponding manipulators.

[0007] For this reason, it is necessary to mount the substrate without contact and to design a corresponding holding, moving and traversing drive device.

[0008] Air bearings for high purity manufacturing environments are well known, but they present problems for the processing steps being performed due to air currents near the substrate.

[0009] Magnetic holding or positioning devices are also known that have a base and a carrier that supports an object.

[0010] In many cases, multiple magnetic bearings with distance sensors and control circuits are provided to contactlessly attach the carrier to the base, keeping the carrier suspended at a predetermined distance from the base.

[0011] Similarly, known solutions for contactless bearing of a carrier that is moved along a fixed base for holding a substrate can have multiple individual or separate magnetic bearings spaced apart in the transport direction.

[0012] To move the carrier along the series of magnetic bearings, it is necessary for the magnetic bearings, which are stationarily disposed on a base, to mechanically interact with the carrier depending on the current position of the carrier during the carrier's transport movement.

[0013] For contactless mounting and contactless transport of the carrier along the path of movement specified by the base, lateral or transverse guide means must also be provided. These can be realized by suitably constructed magnetic bearings.

[0014] Linear motors and linear actuators are known as drives for non-contact transport and corresponding carriers to move along a base.

[0015] One such linear drive is the subject of DE 10 2010 045 437 A1. This linear drive comprises a housing with end plates and a piston movably arranged inside the housing and guided by a piston rod. The end plates, rigidly connected to the housing, have a central guide for a first medium extending into the housing. The end plates or the housing have means for discharging the first fluid medium and means for supplying and discharging a second fluid medium.

[0016] EP 2 346 148 A1 discloses a linear drive for a rotary stroke motor. This drive consists of a winding system with a number of winding coils arranged coaxially and axially consecutively. A moving magnet system with a number of axially consecutive permanent magnets is formed axially relative to the winding system. The winding system is powered by a controlled converter.

[0017] DE 10 2016 121 674 A1 addresses the issue of possible outgassing in lines flowing through a vacuum process chamber. This can lead to foreign and / or particle contamination in the vacuum, thus deteriorating the vacuum quality and potentially affecting the processing results of the corresponding parts. To avoid this problem, it is proposed to combine a first permanent magnet device mounted on a frame with a rotating permanent magnet device mounted on a carriage. Longitudinal guide means are also provided.

[0018] A typical device for holding, positioning, and moving an object using magnetic bearings and a linear motor is described in DE 10 2015 004 582 A1. The linear drive there comprises a linear motor with at least one stator and one slider, which are arranged on a base and a carrier. The linear motor for moving the carrier along the base not only generates a displacement force in the direction of movement or transport, but also generates a counterforce that counteracts the magnetic field present therein. The magnetic bearing is designed as a vertical magnetic bearing for weight compensation and holds the carrier in a floating, non-contact position, thereby achieving improved lateral stability of the carrier.

[0019] What known solutions have in common is that there are still moving interlocking bearings or mechanical elements or corresponding joint contacts and contact points, meaning that all surfaces in contact with the vacuum are subject to particle contamination and outgassing. Summary of the Invention

[0020] It is therefore an object of the present invention to provide a further developed apparatus for holding, positioning and / or moving objects in a process vacuum, which avoids or minimizes particle generation on the vacuum side. [Means for solving the problem]

[0021] The solution to the object of the present invention is provided by the device of the combination of features as set forth in claim 1, the subclaims representing at least useful embodiments and further developments.

[0022] Accordingly, an apparatus for holding, positioning, and / or moving an object, such as a semiconductor substrate, in a process vacuum is contemplated.

[0023] The device comprises a base, an end effector with a substrate holder, and a linear drive connected to the end effector via a carriage.

[0024] The base also has a vertical or lifting drive acting on it. Furthermore, magnetic bearings are used in the aforementioned carriage.

[0025] According to the invention, the linear drive is designed as a fluid, in particular gas, pressurizable but otherwise sealed cylinder with a double-acting piston movably arranged in the cylinder.

[0026] The piston is equipped with a magnetic arrangement.

[0027] The carriage further includes a magnetic ring that at least partially engages the outer periphery of the cylinder and surrounds the cylinder in a non-contact manner.

[0028] The carriage can translate without contact with the base and is also equipped with a magnetic guide to prevent rotational tilt.

[0029] The design consists of a base with a linear drive and end effector connected to a lifting drive. For this purpose, a bearing-equipped shaft is connected to the base.

[0030] The shaft can be rotated about its axis by a magnetic rotary coupler and locked relative to the rotation angle or pivot angle.

[0031] The aforementioned shaft is preferably designed as a hollow shaft, and the fluid for moving the piston in the cylinder of the linear drive can be admitted and withdrawn via corresponding channels in the shaft.

[0032] The base with at least the end effector and substrate holder, linear drive, and magnetic guide are placed in a process vacuum to maintain a surface cleanliness class of less than 10,000 particle generation, less than 10 μg / cm2 cumulative molecular contamination of heavy hydrocarbons, and an outgassing rate of less than 2E-9 mbar-l / (s-cm2).

[0033] The carriage and the magnetic ring may be integrated, and a linear magnetic restraining guide is provided to prevent rotational tilt.

[0034] In one embodiment of the present invention, a balance weight is located at the end opposite the substrate holder.

[0035] The lift drive is located on the atmospheric side, facing away from the process vacuum.

[0036] The magnetic ring can be designed as a ring cylinder with multiple magnetic sections.

[0037] The piston is sealed against the interior or wall of the cylinder by a resilient element disposed in an annular groove.

[0038] In particular, the rodless cylinder design, the fluid-applied piston, and the aforementioned magnet carriage minimize unwanted particle generation. The desired translational displacement of the substrate holder is enabled by the magnet carriage, while rotational tilt is avoided by an additional linear magnetic restraint guide.

[0039] In comparison with the prior art, one of the basic ideas of the present invention is that a fluid-driven double-acting piston is actuated by a fluid in a cylinder closed on all sides, and its movement is transmitted via a magnetic force coupling to a ring surrounding the outside of the cylinder without contact, in order to generate linear motion.

[0040] The invention will now be explained in more detail with reference to exemplary embodiments and by means of the figures. [Brief explanation of the drawings]

[0041] The drawings are as follows:

[0042] [Figure 1] 1 is a cross-sectional side view of an apparatus according to the present invention, including a substrate holder or end effector, a pneumatic cylinder with a piston and magnet, and a recognizable magnetic guide, and a lifting device for generating vertical movement. [Figure 2] 2 is a perspective view (partially cut away) of a device according to the invention similar to FIG. 1, showing details of the magnetic guidance of the linear drive and the magnetic rotary coupler (right part of the image according to FIG. 2). [Figure 3] 1 shows a cross-sectional view of a cylinder and a piston of a linear drive with magnetic guide elements. DETAILED DESCRIPTION OF THE INVENTION

[0043] The apparatus for holding, positioning and / or moving an object, such as a substrate, in a process vacuum starts with a base 4 having a magnetic guide 40 therein.

[0044] An end effector 10 having a substrate holder 1 at one end thereof is translationally and rotationally movable and is guided within a base 4 .

[0045] At the opposite end of the carriage or substrate holder 1 is a counterweight 5 .

[0046] The actual linear actuator consists of a pneumatic cylinder 2 in a base 4 with magnetic guides 40.

[0047] The pneumatic cylinder 2 has a double-acting movable piston 3 therein, and a magnet 30 is configured within the piston 3.

[0048] As can be seen in particular in FIG. 3, on the outside of the cylinder 2 there is a carriage in the form of a magnetic carriage 11 .

[0049] The carriage is connected to the end effector and thus to the substrate holder 1 .

[0050] The movement of the piston 3 is transmitted to the carriage 11 in a non-contact manner due to the interaction between the magnet 30 in the piston and the magnet of the carriage 11 .

[0051] Further guidance and protection against rotational tilt is achieved by a magnetic arrangement 40 in the base and a magnetic arrangement 41 in the area of ​​the carriage.

[0052] An elevator device 6 is provided to generate vertical movement of the base together with the linear drive, and this elevator device 6 is located on the atmospheric side in the process vacuum.

[0053] A part of the vacuum chamber is designated by the reference numeral 9 .

[0054] The linear drive is connected to the lifting device 6 via a shaft 12 .

[0055] As shown in Figures 1 and 2 and the detailed view of Figure 2, the shaft 12 is designed as a hollow shaft and has channels for supplying and discharging fluid for moving the piston via a gas inlet or gas outlet.

[0056] The rotary coupler (see FIG. 2 / detail) allows for rotation or rocking as shown by the arrows in FIG.

[0057] A variable length bellows 7 surrounds the outside of the shaft 12 .

[0058] The shaft is guided at the end and a seal 13 is formed.

Claims

1. 1. An apparatus for holding, positioning, and / or moving an object in a vacuum, comprising: a base (4) having an end effector (10) with a substrate holder (1), a linear drive coupled to the end effector (10) via a carriage (11), and a magnetic bearing for the carriage (11); said linear drive being designed as a fluid-pressurizable, otherwise closed cylinder (2) and having a double-acting piston (3); The piston (3) is provided with a magnetic arrangement (30), The carriage (11) further comprises a magnetic ring (14) which engages with the periphery of the cylinder (2) at least in its outer portion and surrounds the cylinder (2) without contacting it; the carriage (11) is translationally movable without contact with the base (4), fixed against rotation and tilt, and magnetically guided (40; 41); An apparatus characterized in that

2. The base (4) with the linear drive and the end effector (10) is connected to a vertical or lifting drive, in particular a lifting drive (6), A shaft (12) with a seal (13) connected to the base (4) is formed for this purpose.

2. The device according to claim 1, characterized in that:

3. The base (4) can be rotated and locked around the axis of the shaft (12) by a magnetic rotary coupler (8) via the shaft (12).

3. The device according to claim 2, characterized in that:

4. The shaft (12) is designed as a hollow shaft and has channels for supplying and discharging a fluid to move the piston (3) in the cylinder (2) of the linear drive; 4. Device according to claim 2 or 3, characterized in that

5. The end effector (10), the substrate holder (1), the base (4) with the linear drive and magnetic guide are disposed in at least a process vacuum; Maintain a surface cleanliness class of less than 10,000 particle generation, less than 10 μg / cm² cumulative molecular contamination of heavy hydrocarbons, and an outgassing rate of less than 2E-9 mbar·l / (s·cm²); 5. The device according to claim 1, wherein the device comprises:

6. The carriage (11) and the magnetic ring (14) are integrally formed and are fixed against rotation and tilt by a linear magnetic restraint guide.

6. A device according to any one of claims 1 to 5.

7. A balance weight body (5) can be disposed at the end facing the substrate holder (1).

7. The device according to claim 1, wherein the device comprises:

8. The lift drive (6) is optionally positioned on the atmosphere side with the vacuum at its back.

3. The device according to claim 2, characterized in that:

9. The magnetic ring (14) is designed as a ring cylinder with several magnetic sections. Device according to any one of claims 1 to 8, characterized in that

10. The piston (3) is sealed to the cylinder inner wall by an elastic element arranged in an annular groove.

10. Device according to any one of claims 1 to 9, characterized in that

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