GB2623855A

GB2623855A - Sputter ion pump

Info

Publication number: GB2623855A
Application number: GB2308542.6A
Authority: GB
Inventors: Alexander Clement Derek
Original assignee: Edwards Vacuum LLC
Current assignee: Edwards Vacuum LLC
Priority date: 2022-10-27
Filing date: 2023-06-08
Publication date: 2024-05-01
Also published as: GB202308542D0

Abstract

A sputter ion pump 10 comprises: an anode 14 defining a plurality of hollow cylinders and connected to a voltage supply; a cathode comprising a plurality of cathode elements 22 and connected to ground; and magnets 24 in direct contact with the cathode elements. The magnets generate a magnetic circuit perpendicular to a direction of extension of the anode. The anode, cathode and magnets may be connected to a flange 12 and extend perpendicularly from the flange, with the magnetic circuit being parallel to the flange. The sputter ion pump may be inserted into a vacuum apparatus. The anode, cathode and magnets may be completely inside the vacuum. The anode may comprise three anode elements arranged radially around an elongate centre element at 120° to each other. The cathode elements may be angled plates and each cathode element may be in contact with two magnets. The magnets may be surrounded by pole pieces 26.

Description

SPUTTER ION PUMP

The present invention relates to a sputter ion pump and in particular a compact high-performance sputter ion pump to be inserted into a vacuum apparatus.

Conventional sputter on pumps (SIP) comprise an anode provided by a hollow cylinder. At the respective ends of the hollow cylinder, cathodes as metal plates are arranged, wherein anode and cathode are kept at different electrical potentials. In particular, the cathode may be connected to the ground wherein the anode may be connected to a high voltage. Anode and cathode are positioned in a magnetic field provided to the axis of the hollow cylinder by magnets usually disposed outside the cathodes and outside the vacuum. By the voltage between the anode and the cathode, in addition to the magnetic field parallel to the axis of the anode, the paths of free electrons in the anode cells are augmented on spiral trajectories. The free electrons generate ions from the gas molecules inside the vacuum, which are accelerated by the electric field between the anode and cathode. The accelerated ions will impact onto the cathode, wherein both the sputtered and remaining cathode material act as a getters removing the ions from the vacuum.

In common SIPS, in order to enhance the pump performance of the SIP, one or more hollow cylinders as anodes are arranged within the same plane between the cathode plates. Since at least the anode and the cathode of the SIP need to be placed in the vacuum, the building space may be restricted if the SIP shall be placed as close as possible to or within the vacuum chamber to be evacuated. Thereby at the same time the number of hollow cylinders is restricted limiting the pump performance. It is known to reduce the required space by arranging parts of the SIP outside the vacuum such as the magnets. However, this may by disadvantageous since it decreases the magnetic field at the cathode and anode and requires larger magnets than would be necessary if they would be placed closer to the anode and cathode as well as specifically adapted housings of the SIP resulting in an SIP with an overall larger size and weight. Furthermore, when the specifically adapted housing of the SIP is connected to a vacuum apparatus, the distance between the SIP and a vacuum chamber of the vacuum apparatus is increased further decreasing the pump performance.

Thus, it is an object of the present invention to provide a sputter ion pump to be inserted into a vacuum apparatus having an improved pump performance.

The object is solved by a sputter ion pump according to claim 1.

The sputter ion pump (SIP) according to the present invention comprises an anode. The anode defines a plurality of hollow cylinders. Therein, the anode is connected to a voltage supply. Further, the SIP comprises a cathode comprising a plurality of cathode elements arranged directly next to the anode. The cathode elements may by connected to ground or kept at a lower potential than the anode. Further; the sputter on pump according to the present invention comprises magnets in direct contact with to the cathode elements, wherein by the magnets a magnetic circuit is generated perpendicular to a direction of extension of the anode. Thus, according to the present invention, by the magnets a magnetic circuit encircling the anode is created in a plane perpendicular to the axial extension of the anode. Thus, by the specific arrangement of the magnets arid the magnetic circuit a compact configuration of the magnets is achieved.

Preferably, the SIP comprises a plurality of pole pieces in direct contact with the magnets to create the magnetic circuit. Therein, the magnets are attached to the pole pieces by their magnetic force and held in place.

Preferably, the anode has a radial symmetry. By the radial symmetry the number of anode cells, i. e. hollow cylinders, within the volume of the pump can be maximized. Thereby; a compact SIP can be built, which provides improved pump performance without increase of the required building space. Thus, by the specific arrangement of the magnets and the magnetic circuit enabling to apply the magnetic field to the anode having a radial symmetry. Thus, by utilizing the radial symmetry of the anode, the pump performance can he increased and the required building space can be decreased.

Preferably, the SIP is insertable or at least partially insertable into a vacuum apparatus. Thus, the SIP can be placed in close proximity or even within the vacuum apparatus minimizing the distance between the SIP and a vacuum chamber of a vacuum apparatus. Thereby, pump performance can be further increase.

Preferably, the anode and the cathode are connected to a flange. Therein, more preferably the anode and the cathode are completely arranged within the area of the flange. Thus, a compact design is provided. In addition, the magnets and pole pieces may be connected to the flange and preferably within the area of the flange.

Preferably, the anode is directly connected to the flange. Therein, connection of the anode to the flange may be facilitated by supporting elements preferably made from an insulating material. No further intermediate elements are necessary. Thereby, structural stability is increased and at the same time a compact design is achieved.

Preferably, the pole pieces are in direct contact to the flange. No intermediate elements are present to achieve a compact design.

Preferably, the cathode elements are directly connected to the flange via the magnets pole pieces. Thus, the pole pieces carry the cathode elements.

Preferably, the anode and the cathode extend axially from the flange. More preferably, also the magnets and the pole pieces extend axially from the fiance.

Preferably, the flange comprises a first surface and an opposite second surface, wherein the first surface is connected to the second surface by a side surface. The second surface is at least partially arranged in the vacuum, when the SIP is connected or mounted to a vacuum apparatus. The anode and the cathode are connected to the second surface of the flange and preferably extend axially from the second surface.

Preferably, the flange is buift as blank flange, i.e. has a disk shape.

Preferably, the anode extends in an axial direction from the flange which coincides or essentially coincides with the normal direction of the second surface, Le, the axial extension is perpendicular or substantially perpendicular to the second surface.

Preferably, the axis of radial symmetry, coincides or substantially coincides with the normal direction of the second surface, i.e. the axis of radial symmetry is perpendicular or substantially perpendicular to the second surface.

Preferably, the anode and the cathode are connected to a housing of the SIP by the flange. Thus, the fiance itself does not provide any housing of the SIP.

Preferably, the SIP does not provide a housing. Instead, a housing of the SIP is provided by the vacuum chamber of the vacuum apparatus when the SIP is connected or mounted to the vacuum apparatus. Thus, by inserting the SIP into the vacuum apparatus and mounting the SIP via the flange, a vacuum tight housing of the SIP is provided by the vacuum apparatus itself.

Preferably, the SIP is insertable or at least partially insertable into a vacuum apparatus. Thus, the SIP can be placed in close proximity or even within the vacuum apparatus minimizing the distance between the SIP and a vacuum chamber of a vacuum apparatus. Thereby, pump performance can be further increase. In particular, the SIP of the present invention has no housing or casing and the vacuum tight housing necessary for operation of the SIP is provided by a vacuum chamber or vacuum apparatus itself, when the SIP is inserted into the vacuum apparatus.

Preferably, the magnetic circuit is parallel to the flange, i.e. the second surface of the flange. In the case that the anode extends axially from he flange, according to the present invention, the magnetic circuit is arranged in a plane perpendicular to the axial direction of the anode and thus parallel to a surface of the flange. Wherein, the surface of the flange refers to the surface of the flange when mounted disposed in the vacuum of a vacuum apparatus.

Preferably, the anode and the cathode are arranged completely inside the vac-Preferably, the magnets and/or the pole pieces are completely arranged inside the vacuum. If the SIP is connected to a flange, the complete SIP can be inserted into the vacuum by connecting the flange to a vacuum apparatus.

Preferably, the magnetization direction of each magnet is perpendicular to the direction of radial extension of the anode and preferably in a plane parallel to the flange. In particular, the magnetization direction of each magnet is perpendicular to the direction of extension of each anode element. Thus, by the magnetization direction of the magnets a complete magnetic circuit around the anode is created.

Preferably, the magnets are in direct contact with the cathode elements. In particular, the magnets are arranged and in contact on a side of the cathode elements opposite to the anode.

Preferably, each cathode element is in direct contact with two magnets arranged in an angle to each other. Therein, the two magnets are magnetized with opposite polarity to each other in order to create the magnetic circuit. In addition, by implementing two individual magnets each in contact with one respective cathode element, the magnets can be arranged in an angle with respect to each other without machining the magnets itself in order to achieve the radial symmetry of the SIP. Since, in particular most of the magnet materials are brittle, machining and in particular bending of the magnets would be difficult. Thus, by implementing two individual magnets arranged in an angle to each other manufacturing is simplified.

Preferably, the magnets are built as straight plates. Thereby, as descnbed above, manufacturing of the magnets is facilitated.

Preferably, the anode comprises a plurality of anode elements connected at a centre element and arranged in radial symmetry. Thus, the anode elements are arranged in an equal angle to each other. Therein, each anode element comprises one or more hollow cylinders. Thus, by the number of anode elements the number of anode cells, i. e. hollow cylinders, can be increased without increasing the overall dimensions of the SIP.

Preferably, the centre element coincides with the axis of radiai symmetry.

Preferably, the extension of the centre element is along or substantially along the normal direction of the second surface of the flange, i.e. perpendicular or substantially perpendicular to the second surface.

Preferably, the anode elements extend radially from the centre element.

Preferably, all anode elements are built identically. Alternatively, at least two of the anode elements are built differently. This relates in particular to one or more of the size of the anode cells, the arrangement of the anode cells and the m-her of anode cells in each of the anode elements.

Preferably, the anode cells extend in a direction perpendicular or substantially perpendicular to the axial extension of the anode. Since the anode cells are built as hollow cylinders, their centre axis corresponds to the direction of extension.

Preferably, the anode cells, i.e. their centre axes, extend in a direction perpendicular or substantially nerpendicular to the axis of radial symmetry.

Preferably, the anode cells, i.e. their centre axes, extend in a direction parallel or substantially parallel to the flange, in particular to the second surface of the flange.

Preferably, the anode comprises three anode elements arranged in 1200 relative to each other. Alternatively, the anode comprises four anode elements arranged in 90° relative to each other. In the case that the anode comprises three anode elements, each anode element may comprise 6 anode cells/hollow cylinders resulting in 18 anode cells of the SIP in a very compact space. In particular, the radial symmetric arrangement of the anode elements can be fit to the size of the flange thereby further reducing the space requirements of the SIP.

Preferably, the number of cathode elements is equal to the number of anode elements. Thus, in the case that the anode comprises three anode elements also three cathode elements are present in the SIP.

Preferably, each cathode element is integrally built or, in other words, a single piece. Further, due to integrally building the respective cathode elements, the number of necessary elements is reduced thereby simplifying the assembly.

Preferably, the number of pole pieces is equal to the number of cathode elements. Thus, in the case that the SIP has three cathode elements, also three pole pieces are present in the SIP.

Preferably, the magnetic circuit encircles the complete anode and preferably all anode elements. Thus; there is no individual magnetic circuit for each anode or anode element. Instead, there is a common magnetic circuit for all anode elements thereby simplifying the structure of the magnets necessary for providing the magnetic circuit and reducing at the same time the required building space.

Preferably, the pole pieces are made from soft iron or soft metal. In particular the pole pieces are made from electroless nickel plated mild steel that shows reduced ouLciassino in the vacuum.

Preferably, the pole pieces are built as angled plates in order to conform the cathode elements and the magnets in contact with the cathode elements. Therein, in particular if the anode has three anode elements arranged in an angle of 1200 relative to each other, also the pole pieces are angled with an angle of 120°. For other configurations of the anode, the angle might deviate arid for example for four anode elements the pole pieces are built as angled plates having an angle of 90°.

Preferably, the pole pieces are in direct contact with the magnets and in particular in contact with a surface of the magnets opposite to the cathode elements.

In particular, if the magnets are built as straight plates or each cathode element is in direct contact with two magnets arranged in an angle relative to each other, the respective pole piece is in direct contact with two magnets as well. Hence, the magnets are sandwiched between the pole pieces and the cathode elements.

Preferably, each pole piece comprises a recess to receive at least partially one or more of the magnets. By the recess the position of the magnets is determined and without additional fixing measures such as soldiering, brazing or the like, a durable connection between the pole pieces and the magnets is provided.

In the following the present invention is described in more detail with reference to the accompanying drawings.

The figures show: Figure 1 a perspective view of the sputter ion pump according to the present invention, Figure 2 a detailed view of the anode, Figure 3 a sectional view of the anode in a mounted state, Figure 4 a top view of the sputter ion pump of figure 1 and Figure 5 a detailed view of e magnets of figure 1.

Referring to Figure 1 showing a sputter on pump (SIP) according to the present invention. The SIP 10 is mounted on a flange 12 and all parts of the SIP 10 (including but not limited to the anode 14, the cathode elements 22 and the magnets 24, all described in more detail below) can be inserted into the vacuum by connecting the flange 12 to a vacuum chamber or vacuum apparatus. Therein, the SIP 10 comprises a radial symmetry in order to fit into the area of the flange 12. By the radial symmetry the space provided by the flange 12 is efficiently used, thereby enhancing the pump performance of the SIP 10 without increasing the required building space.

IC

The SIP 10 comprises an anode 14 shown in detail in Figure 2. The anode 14 in the example of the figures comprises three anode elements 16, which are arranged with a radial symmetry and an angle of 1200 relative to each other. Thereby a radial symmetry is established relative to a symmetry axis 20. Other configurations are possible as well. For example, the anode 14 may have four anode elements which are arranged with an angle of 90° relative to each other. Therein, the anode elements 16 are connected to a centre element 18, wherein the symmetry axis 20 runs through the centre element 18 and the anode elements 16 extend radially from the centre element 18. Therein, in the example of the present figures, each anode element 16 comprises six hollow cylinders 22 arranged in a 2D array. Other configuration and in particular other numbers of hollow cylinders are possible. Therein, the hollow cylinders have a diameter between 10 -30 mm and preferably between 15 -20 mm. In order to increase the precision of the anode 1.4, the anode 14 is built from a single piece facilitating assembly of the anode 14.

Referring to Figure 3, the anode 14 is connected to a voltage supply (not shown) outside the vacuum via an electrical feedthrough 40. Therein, the flange 12 comprises an opening 48. A conductor 42 extends through the opening arid is surrounded by an insulating material 44, preferably built from a ceramic material. Therein, the insulating material 44 and the conductor 42 passes through the flange 12 in a vacuum tight manner. The conductor 42 is directly connected to the anode 14 and preferably at the centre element 18 of the anode 14. Hence, no additional conductors within the vacuum are required connecting the anode to the voltage supply, since the conductor 42 extends from the outside of the vacuum into the vacuum and is directly connected to the anode 14.

Further, referring to Figure 3, the anode 14 is supported by supporting elements 30 comprising pegs 36 which are attached on the bottom surface of the anode 14. Similar, corresponding pegs 38 are attached to the flange 12 or a base element 29. The peas 36 of the anode 14 may be integrally built with the anode 14. Similar, the pegs 38 of the flange 12 may be integrally built with the flange 12 or the base element 29. Further, each supporting element 30 comprises a ceramic element 34, wherein the peg 36 of the anode 14 and the peg 38 of the flange 12 are received by the ceramic element 34. The ceramic element may have a sleeved shape with an opening, wherein the opening is configured to receive the pegs 36,38. Therein, the opening of the ceramic element 34 is big enough to receive the pegs 36, 38. By the ceramic element the peg 36 of the anode 14 is kept in a distance from the peg 33 of the flange 12 to avoid shorts or sparks. Alternatively, instead of pegs 38 connected to the flange 12 or the base element 29, the flange 12 or the base element 29 may comprise recessions or troughs which receive the ceramic element 34. Therein, the number of supporting elements may correspond to the number of anode elements 16. Thus, each anode element is structurally connected to the flange by the supporting elements 30. Preferably, similar supporting elements may be arranged on the upper side of the anode (not shown), wherein the supporting elements on the uppers side of the anode 14 are received by a cap element 28. The cap element 28 may also support a NEG pump module connected to the SIP 10 in a stacking manner in order to create a combined NEG-SIP pump module, wherein the NEG as well as the SIP are within the area of the fiance 12. Thus, NEG and SIP can together be inserted into a vacuum chamber.

Further, the supporting elements 30 are surrounded by sputter shields 32 preferably welded to the anode 14 and preventing elements from the cathode being sputtered onto the ceramic elements 34 and creating a conductive path from the anode to ground of the flange 12.

Referrina back to Figure 1. The anode 14 is surrounded by cathodes, wherein the cathodes are built from respective cathode plates 22, 22', 22". The cathodes may have a thickness between 0.5 mm and 2 mm and more preferably between 1 mm and 1.2 mill, In particular, the thickness may be between 0.5 mm and 2 mm for a titanium cathode and between 0.5 mm and 1 mm for a tantalum cathode, If the anode 14 has three anode elements arranged with an angle of 120° relative to each other, the cathode plates 22, 22', 22" are also angled by 120°. Therein, a first part, of each cathode plate 22, 22', 22" is arranged directly next to a first anode element 16, wherein the second part of the cathode plate 22, 22', 22" is arranged directly next to a subsequent anode element 16. Thereby, each cathode plate 22, 22', 22" overlaps with two different anode elements 16 thereby reducing the number of necessary parts for the SIP and facilitating assembly thereof.

Preferably, the first cathode plate 22 and the second cathode plate 22' are built as titanium cathodes, wherein a third cathode plate 22" is built as tantalum cathode plate. By the different materials, different types of sputter ion pumping are enabled. Thus, by the tantalum cathode plate 22" DI pumping is enabled with two anode elements, wherem by the titanium cathode plates 22, 22' conventional pumping (CV) is enabled. Thereby, each cathode plate 22, 22', 22" is entirely built only from one material. Thus, welding or brazing together plates from different materials is not necessary, thereby simplifying the structure of the present SIP.

The cathode plates 22, 22', 22" are connected to the flange via a base element 29 as shown in Figure 3. Therein, the cathode plates 22, 22', 22" may be held in place within the pump assembly by the base element 29, the pole pieces 26, and cap eiement 28. Therein, the cathode plates 22, 22', 22" may be clamped between the pole pieces 26 and the base element 26, preferabiy together with the magnets 24L Directly connected to the cathode plates 22, 22', 22" magnets 24 are arranged and connected to a surface of the cathode plates 22, 22', 22" opposite to the anode 14. Therein, preferably two magnets are in direct contact with one cathode plate 22, 22', 22" arranged with an angle of 1200 relative to each other.

Thus, on both sides of each anode element 16 one magnet 24 is arranged in order to create a magnetic field in an axial direction of hollow cylinders of the anode 14. Preferably, the magnets are samarium cobalt magnets but can be also built as neodymium magnets or the like.

In the example of the Figures, the SIP comprises six magnets 24. By the individual magnets a magnetic circuit is created. Rather than closing a magnetic loop from the magnet on one side of the anode to the magnet on the other side of the anode preferably by a yoke as in the prior art, the magnetic circuit created for the SIP according to the present invention forms a combined closed loop around all anode elements. The magnetic: field goes across the respective gaps and the respective tips of the anode elements 16 opposite to the centre element 18 of the anode 12 to the magnet on the other side. It is then directed to the magnet of the adjacent anode element. The loop is closed alter the field crosses the other two gaps and is redirected to the starting position. The magnetic circuit is indicated by arrows 54 in Figure 4. Hence, the magnetic circuit is circular in a plane perpendicular to the axial direction of the SIP or in a plane parallel to the surface of the flange 12. By this specific design of the magnetic circuit a radial symmetric arrangement of the SIP is provided leading to a compact and an efficient SIP.

Referring back to Figure 1, the magnets 24 are surrounded by pole pieces 26 which are also bend by an angle of 120 degree, i. e. having the same angle as the anode elements 16 relative to each other. The pole pieces 26 have a thickness of between 3 mm and 10 mm and preferably between 4 mm and 8 mm and are made of a soft steel plate or sheet, holding the magnets in place and guiding the magnetic flux. The pole pieces 26 are fixed to the base element 29 and in direct contact with the flange 12. As shown in Figure 5 the pole pieces 26 comprise a recess 52 in order to receive the magnets 24 with high precision and small tolerances. Thus, the magnets 24 are kept in place by the respective recess 52 without the need of additional fixtures.

Similar to the base element 29, the pole pieces are fixed to a cap element 28, fixing the cathode plates 22 in an axial direction. As shown in Figure 5, also the cap element 28 comprises a recess 53 receiving the cathode plates 22 and the magnets 24. Therein, the cap element 28 may be configured to mount an NEG module on too of the SIP in order to create a combined NEG-SIP pump module, wherein the NEG as well as the SIP are within the area of the flange 12, Thus, NEG and SIP can together be inserted into a vacuum chamber.

Hence, by the present invention a compact design of a high performance SIP is provided exploiting a new design by implementing the radial symmetry of the anode and the additional elements. Thereby, the cathode, the magnets, the pole pieces and also the magnetic circuit are adapted to provide a high pomp performance.

Further aspects of the present invention: Aspect 1: Sputter ion pump comprising: an anode, wherein the anode defines a plurality of hollow cylinders and is connected to a voltage supply, a cathode comprising a plurality of cathode elements arranged directly next to the anode arid connected to around, wherein at least two cathode elements are made from a different material.

Aspect 2: Sputter ion pump according to aspect wherein the anode comprises a radial symmetry.

Aspect 3: Sputter ion pump according to aspects 1 or 2, wherein the anode and the cathode are connected to a flange.

Aspect 4: Sputter ion pump according to aspect 3, wherein the anode and the cathode are completely arranged within the area of the flange; Aspect 5: Sputter ion pump according to aspects 3 or 4, wherein the anode and the cathode extend axially from the flange.

Aspect 6: Sputter ion pump according to any of aspects 1 to 5, wherein the anode and the cathode are arranged completely inside the vacuum.

Aspect 7: Sputter on pump according to any of aspects 1 to 6, wherein the anode comprises a plurality of anode elements connected at a center and preferably arranged in a radial symmetry, wherein each anode element comprises one or more hollow cylinders.

Aspect 8: Sputter ion pump according to aspect 7, wherein the anode comprises three anode elements arranged in 120° relative to each other.

Aspect 9: Sputter ion pump according to aspects 7 or 8, wherein the number of cathode elements is equal to the number of anode elements.

Aspect 1.0: Sputter ion pump according to any of aspects 7 to 9, wherein each cathode element overlaps with two anode elements.

Aspect 1.1: Sputter ion pump according to any of aspects 1 to 10, wherein the cathode elements are built as angled plates preferably with an angle of 120°. Aspect 12: Sputter ion pump according to any of aspects 1 to 11, wherein each cathode element is made from a singe material.

Aspect 13: Sputter ion pump according to any of aspects 1 to 12, wherein at least one cathode element is entirely built from Titanium and/or wherein at least one cathode element is entirely built from Tantalum.

Aspect 14: Sputter ion pump according to any of aspects 1 to 13, wherein at least one cathode element and the anode acting as conventional, CV, sputter ion pump and at least one cathode element and the anode acting as differential, DI, sputter ion pump.

Aspect. 15: Sputter ion pump according to any of aspects 1 to 14, wherein the ratio between CV pumping and DI pumping is between 50:50 and 33:67. Aspect 16: Sputter ion pump according to any of aspects 1 to 15, wherein the anode is built as one piece.

Aspect 17: Sputter ion pump according to any of aspects 1 to 16, wherein the anode is connected to the voltage supply by a feedthrough connector, wherein the feedthrough connector is directly connected to the anode.

Aspect 18: Sputter ion pump according to any of aspects 1 to 17, wherein the anode comprises a plurality of supporting elements to fix the anode in a mounting position, wherein the supporting elements are made from an electrical insulation material, preferably a ceramic material, Aspect 19: Sputter on pump comprising: an anode, wherein the anode defines a plurality of hollow cylinders and is connected to a voltage supply, a cathode comprising a plurality of cathode elements arranged directly next to the anode and connected to ground, wherein the anode comprises a radial symmetry.

Aspect 20: Sputter ion pump c ding spect 19, wherein the anode and the cathode are connected to a flange, Aspect 21: Sputter ion pump according to aspect 20, wherein th node a 1 cathode are completely arranged within the area of the flange.

Aspect 22: Sputter ion pump according to aspects 21 or 22, wherein the anode and the cathode extend axially from the flange.

Aspect 23: Sputter ion pump according to any of aspects 19 to 22, wherein the anode and the cathode are arranged completely inside the vacuum.

Aspect 24: Sputter ion pump according to any of aspects 19 to 23; wherein the anode comprises a plurality of anode elements connected at a center and arranged in a radial syrnmetr-, wherein each anode element comprises one or more hollow cylinders.

Aspect 25: Sputter ion pump according to aspect 24; wherein the anode comprises three anode elements arranged in 120° relative to each other.

Aspect 26: Sputter ion pump according to aspects 24 or 25, wherein the number of cathode elements is equal to the number of anode elements, I 7 Aspect 27: Sputter ion pump according to any of aspects 24 to 26, wherein each cathode element overlaps with two anode elements.

Aspect 28: Sputter ion pump according to any of aspects 19 to 27, wherein the cathode elements are built as angled plates preferably with an angle. of 1.20°.

Aspect 29: Sputter on pump according to any of aspects 19 to 28, wherein at least two cathode elements are made from a different material.

Aspect 30: Sputter ion pump according to any of aspects 19 to 29, wherein each cathode element is made from a single material.

Aspect 31: Sputter on pump according to any of aspects 19 to 30, wherein at least one cathode element is entirely built from Titanium and/or wherein at least one cathode element is entirely built from Tantalum.

Aspect 32: Sputter on pump according to any of aspects 19 to 31, wherein at least one cathode element and the anode acting as conventional, CV, sputter ion pump and at least one cathode element and the anode acting as differential. DI, sputter ion pump.

Aspect 33: Sputter ion pump according to any of aspects 19 to 32, wherein the ratio between CV pumping and DI pumping is between 50:50 and 33:67.

Aspect 34: Sputter ion pump according to any of aspects 19 to 33, wherein the anode is built as one piece.

Aspect 35: Sputter ion pump according to any of aspects 19 to 34, wherein the anode is connected to the voltage supply by a feedthrough connector, wherein the feedthrough connector is directly connected to the anode, Aspect. Sputter ion pump according to any of aspects 19 to 35, wherein the anode comprises a plurality of supporting elements to fix the anode in a mounting position, wherein the supporting elements are made from an electrical insulation material, preferably a ceramic material. "i

Reference signs

SIP

1-) flange 14 anode 16 anode element 18 centre element symmetry axis 21 hollow cylinder 22, 22°, 22" cathode plates 24 magnet 26 pole piece 28 cap element 29 base element support element 32 sputter shield 34 ceramic element 36 peas 38 pegs electrical feedthrough 42 conductor 44 insulation element 43 opening 52 recess 53 recess 54 magnetic cir

Claims

LCLAIMSSputter ion pump corn wising: an anode, wherein the anode defines plurality of hollow cylinders and is connected to a voltage supply, a cathode comprising a plurality of cathode elements arranged directly next to the anode and connected to ground, and magnets in direct contact with the cathode elements wherein by the magnets a magnetic circuit is generated perpendicular to the direction of extension of the anode.
2. Sputter ion pump according to claim 1, wherein the SW is ns able into a vacuum apparatus.
3. Sputter ion pump according to claim 1 or 2, wherein the anode and the cathode are connected to a flange.
4. Sputter ion pump according to claim 3, wherein the anode, the cathode and the magnets are completely arranged within the area of the flange.
5. Sputter ion pump according to claims 3 or 4, wherein the anode, the cathode and the magnets extend axially from the flange.
6. Sputter on pump according to any of claims 3 to 5, wherein the magnetic circuit is parallel to the flange.
Sputter ion pump according to any of claims 1 to 6, wherein the anode. the cathode and the magnets are arranged completely inside the vacuum,
8. Sputter on pump according to any of claims 1 to 7, wherein the magneti-zation direction of each magnet is perpendicular to the direction of radial extension of the anode and preferably in a plane parallel to the flange.
9. Sputter ion pump according to any of claims 1 to 8, wherein the magnets are in direct contact with the cathode elements.
10. Sputter on pump according to any of claims 1 to 9, wherein each cathode element is in direct contact with two magnets arranged in an angle to each other.
11. Sputter ion pump according to any of claims 1 to 10, wherein the magnets are built as straight plates,
12. Sputter ion pump according to any of claims 1 to 11, wherein the anode comprises a plurality of anode elements connected at a center element and arranged in a radial symmetry, wherein each anode element comprises one or more hollow cylinders.
13. Sputter ion pump according to claim 1.2, wherein the anode comprises three anode elements arranged in 120° relative to each other,
14. Sputter ion pump according to claims 12 or 13, wherein the magnets are surrounded by pole pieces and the number of pole pieces is equal to the number of cathode elements.
15. Sputter ion pump according to any of claims 1 to 14, wherein the magnetic circuit encircles the complete anode and preferably all anode elements.
16. Sputter ion pump according to any of claims 1 to 15, wherein the magnets are surrounded by pole pieces.
17. Sputter ion pump according to claim 16, wherein the pole pieces are built as angled plates preferably with an angle of 1200.
18 Sputter ion pump according to any of claims 16 or 17, wherein each pole piece comprises a recess to receive at least partiafly one or more of the magnets.