WO2023227322A1

WO2023227322A1 - Process device for pecvd-processing

Info

Publication number: WO2023227322A1
Application number: PCT/EP2023/061177
Authority: WO
Inventors: Jörg Kerschbaumer
Original assignee: Evatec Ag
Priority date: 2022-05-27
Filing date: 2023-04-27
Publication date: 2023-11-30

Abstract

A process device to treat at least one side of a flat substrate under vacuum, the process device (1) comprising: a central process chamber (7), a cover (13) having a gas inlet (4) and extending outward in a closing plane (P_c) with its circumference over an outer diameter of a pumping channel (9), the pumping channel (9) being connectable to one or more vacuum pumps (12), the pumping channel further encompasses at least a major part of the process chamber and is, at least in a closed state of the process chamber, in fluid connection to the process chamber via a circumferential pump slot (8) a pedestal (14) to support the flat substrate (17), the pedestal extending outward in a closing plane (P_c) with its outer circumference over an outer diameter of the pumping channel, and being bidirectionally, linearly movable into an open position and into a closed position, to open and close at least the pumping channel.     

Description

PROCESS DEVICE FOR PECVD-PROCESSING

The present invention refers to a process device to treat at least one side of a flat substrate according to claim 1 and to a multichambered process system (MCS) comprising such a process device according to claim 13.

DESCRIPTION OF THE RELATED ART

Process devices and multichambered process systems (MCS) are known since long in the field of semiconductor industries.

An example of an MCS comprising a stack of process systems, there referred to as plasma chambers, are disclosed in fig.2(a) from US5515986, Balzers AG. Details of the plasma chamber can be found in fig.7(a), details of the pumping arrangement in fig.5b, and details of the suction arrangement in fig.8(a) - 8(e). The document further discloses a loading and de-loading of the flat workpieces through the sidewalls of the process chambers which makes access difficult to the process cavity of the plasma chamber.

More recently state of the art devices disclosed loading of flat substrates like wafers from the bottom, which gives an easier access at least to the pedestal or chuck when the device is opened. However, such state-of-the-art devices may still make it difficult to access a pumping channel or respective pump slots which tend to agglomerate residuals of PECVD-processes and therefor need to be serviced and cleaned at regular intervals. In addition, when high temperatures must be applied in the process chamber, especially to the chuck, e.g., to heat up a wafer quickly to the required process temperature. Further on many devices as known from the state of the art are not designed to perform high temperature processes under vacuum tight conditions, especially when a process pressure as applied in the process device is higher than a high vacuum environment of a surrounding MCS-chamber. DEFINITIONS

Processing devices for CVD processes or PE-CVD processes as disclosed can be operated under atmospheric pressure, over reduced pressure until usual vacuum conditions in a defined gas atmosphere. In the following the term vacuum is used for any type of reduced pressure from some 100 mbar to 10’⁶ mbar, unless specified, e.g., by HV, which stands for high vacuum and extends over a pressure range from 10’³ to 10’⁸ mbar according to common definitions. PE-CVD processes are preferably performed under vacuum. Preferred pressure ranges are given below.

A gas shower can be in its most simple form be designed as a perforated sheet, as a plate of a minimum thickness comprising a respective number of small through holes to increase the flow resistance and allow better gas mixing in the preceding gas distribution chamber or can be formed as a binary tree type pipe construction.

SUMMARY OF THE INVENTION

Therefore, it is an object of the present invention to avoid the disadvantages of the state of the art and to provide a process device which needs less cleaning and service. Therewith it is an object to reduce the number of parts, surfaces and/or sealing gaps within or directly adjacent to the process chamber, whereby the number of particles produced during a PE-CVD-process can be reduced. It is a further object of the invention to ease and improve the tightness of the device with respect to a high vacuum environment, which should not be spoiled by process residuals of the process device.

It is a further object to improve the temperature uniformity of the pedestal which can be a chuck, and therewith keep more uniformly the temperature of a flat substrate, e.g., a wafer, hold on the pedestal.

A process device according to the invention comprises: a central process chamber; a cover having a gas inlet which can be attached to a process-gas supply and extending outward in a closing plane (P_c) with its circumference over an outer diameter of a pumping channel; the pumping channel being connectable to one or more vacuum pumps, e.g. via a pumping line and respective fittings to the pumping nozzles, the pumping channel further encompasses at least a major part of the process chamber, e.g. at least about 75%, preferable however about 100% of the diameter, and is at least in a closed state of the process chamber in fluid connection to the process chamber via a circumferential pump slot, i.e. the pump slot opens with one end in the process chamber and opens with the other end in the pumping channel. Alternatively pump holes being circumferentially arranged in the side wall(s) of the process chamber may be used. Pump slot and pump holes can be arranged in a symmetry plane S of the process chamber. Therewith in a closed state, a fluid path is set between the gas inlet of the process chamber to a vacuum pump, wherein the gas inlet may comprise a gas shower, a gas ring or even in its most simplified design a central opening or nozzle in the cover which forms a top of the processing chamber, or a top of an optional gas distribution chamber when used. The fluid path further comprises the process chamber, the pump slot or the pump holes, the pumping channel, a pumping line and a valve guiding to the vacuum pump in the above sequence; a pedestal, which can be a chuck, to support the flat substrate and preferably to exchange heat from the pedestal to the flat substrate and/or vice-versa form the bottom of the process device. Heating and/or cooling means, back gas channels with a respective separate back-gas supply and an electrostatic chuck (ESC) may be provided as known from the state of the art. The pedestal extends outward in a closing plane (P_c) with its outer circumference over an outer diameter of the pumping channel and is bidirectionally and linearly movable into an open position and into a closed position, to open and close at least the pumping channel. The closing plane (P_c) being defined as the plane where sealing means from the cover and the pedestal touch each other to close at least the pumping channel towards the atmosphere surrounding the process device.

In an inventive embodiment, the process chamber can be open at the same time with the pumping channel and the process chamber may be closed at the same time in the closed position, e.g., due to the movement of the pedestal. The open / closed position is also referred to as open / closed state in the following.

In the open position also the pump slot may be open at the same time with the pumping channel and in the closed position the fluid connection of the pump slot is formed. At least one of the pumping channel, the process chamber, or the pump slot can be formed in the closed position by opposing surfaces of the cover and the pedestal. The opposing surfaces may comprise cavities which are open towards the closing plan (P_c) in the open position at least in the region of the pumping channel and in the region of the process chamber. Respective cavities can be formed completely or in part in one of the pedestal and/or the cover.

In a further inventive embodiment, at least the cavity for the pumping channel can be formed in the cover. For practical reasons like easy cleaning and service it may be favorable to form the cavities of the pumping channel and the process chamber at one side, e.g., in the cover. Thereby the surface of the chuck can be kept flat towards the closing plane (P_c) which facilitates the loading of the flat substrate which can be a wafer as an example.

Polymer sealings, e.g., viton sealings, may be used for processes up to maximum 300°C, ceramic sealings may be used for very high temperature applications, e.g., for temperatures higher than 500°C. However, for PE-CVD processes which are often performed at temperatures from 300 to 500°C, especially metallic sealings means can be provided on or with opposing surfaces of the cover, the sealings in a ground plane projection comprising the ring like opening of the pumping channel, which opens towards the handling chamber in the open position and is closed by a linear movement of the pedestal along axis A3 towards the handling chamber. Despite of the fact that in principle any known sealing means like a flange versus a type of O-ring gasket made of plastics, metal, or ceramics can be used, metal to metal sealings are preferred due to their high mechanical toughness and the high temperature processes which are necessary for certain PE-CVD processes, needing a chuck temperature between 250 to 500°C, especially between 300 and 400° C far above the highest operating temperature of plastic gaskets. However, in a preferred embodiment of the present invention the sealing means comprise or consist of two metallic flanges provided on or with the opposing surfaces of the cover and the pedestal. The metallic flanges can be made of aluminum, stainless steel, or any other construction material which may be best fit for the sometimes very corrosive atmosphere of EP-CVD processes. This will usual be also the preferred construction material for the pedestal and the cover, despite of the fact that certain components for special embodiments, like microwave windows, or coupling walls for inductively power and the like may be made of other constructive materials like heat resistant glass or ceramics. Therewith, when the cover and the pedestal are made of the same material as the flange, the cover, respectively the pedestal can be made as one piece with the flange. A surface roughness R_a of the flanges can be set from 2.0 to 4.5 mp, especially from 2.5 to 4.0 pm. Planarity should be from 0.005 to 0.1 mm, especially from 0.01 to 0.08 mm for a 360 mm diameter. Contact pressure should be tight but avoid any deformations of surfaces, see also next paragraph.

A centering means or device to define the positions between the cover and the pedestal may be provided. In case of a use of the system in or attached to an inner wall of a high-vacuum handling chamber of a multi-chambered system (MCS) as described further below, the pedestal drive which allows to open and close the pumping channel. Such drive may set a respective closing pressure to avoid exchange of atmospheres even against a negative pressure difference between a high vacuum atmosphere (p3) in the surrounding multi-chamber system and the process pressure pi in the process chamber, respectively the pressure in the pumping channel (p2). Wherein pi > P2 > P3, and pi can be from about 0.1 to about 3 mbar, especially from 0.5 to about 2 mbar, p2 can be from about l*10^-3 to about 5*10^-2 mbar, especially from 2*10^-3 to about 3*10^-2 mbar and p3 can be from about 10’⁶ to about 10’⁵ mbar. During cleaning processes of the process device p3 may be set higher than pi and p2 and nitrogen or other inert gases may be flushed through the handling chamber. With a pressure difference of about 2 mbar between p2 and p3 and a diameter of 360 mm, which gives an effective surface of 203'600 mm², of the cover, respectively the pedestal, only a small force of about 20.4 N must be considered, so that no special drives are necessary for such applications.

In a preferred embodiment, which can be combined with any other of the embodiments, the processing device comprises at least one electrode with a power supply to apply a plasma in the process chamber of the processing device. The electrode can be the pedestal, respectively an electrically isolated part of the pedestal which supports the substrate, and/or a counter electrode in parallel to the pedestal near the top of the process chamber. The counter electrode can be the gas shower or a ring electrode, e.g., a ring electrode mounted round the gas shower. The power supply or supplies can be DC, pulsed DC, or RF supplies or any combination thereof.

The inventive process device can be used as a standalone device, or mounted to, respectively in a MCS as shown in the following.

A further object of the present invention is to provide multichambered process system (MCS) having the benefits as described above and with the examples as described at the hand of the figures below. Such MCS comprising: a high vacuum handling chamber, a high vacuum pump connected to the handling chamber, at least one load-lock chamber to load and unload at least one flat substrate into and out of the high vacuum handling chamber, at least one treatment chamber attached to the high vacuum handling chamber, e.g., via a separate vacuum port, an inventive process device as described above is mounted in the handling chamber, e.g., at the ceiling or the bottom of the handling chamber, at least one handler to load a flat substrate from the handling chamber into the treatment chamber and/or the process device.

The process device is further connected via a pumping line to a separate vacuum pump, which can be placed beside or mounted to an outer wall of the MCS, to pump the process device separately when process gas is delivered via the gas inlet. The concept of separating the whole vacuum path from the process device against the HV-space of the MCS, respectively its HV-handling chamber(s) helps effectively to avoid that particle emission from PE-CVD processes performed in the process device would spoil the handling chamber or other parts of the MCS connected to the handling chamber. A gas delivery system is connected to the gas inlet of the process device. The gas delivery system usually will comprise at least one gas reservoir and at least one gas line and optional a gas mixing device, e.g., a gas distribution chamber and gas shower.

Treatment chambers may comprise etching, PVD- or CVD- treatment chambers for respective cleaning, etching or deposition processes.

In a further embodiment of the invention the MCS may comprise at least two handling chambers each connected to at least one treatment chamber and arranged round a robot chamber in the center of the MCS, the latter comprising the handler and can be separated from each handling chamber and the load lock chamber by a gate valve. In an alternative embodiment, the handler may be positioned in the gate lock.

The handler can be any type of handler, respectively robot especially comprising fixed or movable mounted two, three and multiaxial handlers or robots, e.g., SCARA-robots. The MCS as well as the process device will have usual control systems, comprising a central and/or peripheral processing units to control and synchronize respective components like valves, pumps, gas flows, heating and cooling systems and drives as usually come with complex vacuum systems and not further mentioned here.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the prior art and of the present invention are described in more detail below by way of example with reference to the figures. Reference signs which describe the same features as shown/described with the state of the art in Fig.lA or IB are designated with the same numbers also in the following figures describing inventive embodiments of the MCS, the process device, and details therefrom. However, reference signs which refer to a system, a device or a detail of the prior art and differ from the respective components according to the invention, are of a different design, or are not used in embodiments according to the invention are marked with a single apostrophe. The figures show:

Fig.lA a schematic side section of an MCS with a known process device in a closed position inside the MCS;

Fig. IB the same side section of Fig.lA with the process device in an open position;

Fig.2A a schematic side section of an inventive MCS with an inventive process device in a closed position;

Fig.2 B the same side section of Fig.2A with the process device in an open position;

Fig.3 A top view of an inventive process device and MCS;

Fig.4A-C Embodiments of inventive process devices in partial side view. DETAILED DESCRIPTION OF THE FIGURES

Fig.lA shows an exemplary embodiment of a side section of an MCS 30' with a known process device 1'. The process device 1' is shown in a closed position inside the MCS.

The process device 1' is a device which is especially designed for PE-CVD comprising two electric power supplies 25, 26, in this case RF power supplies, for the chuck type pedestal 23 and a counter electrode, which can be as shown an electrically isolated gas shower 6, or any other part of the cover 1'. Thereby electric power can be fed via power lines 27 and 28 according to the process needs, together or individually.

A flow path of a process gas is shown with closed arrows within the process device. Coming from the gas supply or gas supplies 2 and gas line(s) 3 into a gas distribution chamber 5, where process gases can be mixed in case that more than one process gas is used, the gas flows via the gas shower 6 into the process chamber 7', where it is reacted. The respective residual gas is pumped via a pump slot 8' and a circumferential pumping channel 9'. Finally, a pumping line 10 guides the residual gas out of the process device 1' and the MCS 30' via a pump valve 11 to the vacuum pump 12.

The process chamber is sealed against the handling chamber respectively, vice versa, as a high vacuum handling chamber is used, by sealings 20' and 21', where 20' is a flange surface and 21' an O-ring type gasket. The process chamber 7 of the process device 1' can be opened by a pedestal drive 23 along axis A3 into an open position as shown in Fig.lB.

In the open position loading and unloading of the process chamber 1' can be performed by a handler 37 comprising two arms rotatable round axis Al and A2 (rotating v- arrows), the terminal arm 38 comprising or being designed as an end effector to pick up a wafer from pins 22 which can be extended from the pedestal for loading and unloading operations. The wafer can then be transferred in high vacuum (HV) to a treatment chamber 34-36, to a wafer magazine 41 inside the handling chamber, or to a load lock chamber 33 to transfer the wafer from the handling chamber to atmosphere (see Fig.3). The HV atmosphere is generated by a HV pump 32 and a HV valve 39 attached to the HV handling chamber 30'.

With state-of-the-art process devices pumping channel 9' has to be opened separately either as a whole or by service ports and the pump slot 8' has to be accessed via the pumping channel and/or the process chamber (not shown).

Figs.2A and 2B show an MCS 30 with an inventive process device 1, similar to Figs.lA and IB, with the process device 1 in a closed position for processing in Fig.2A and in an open, load/unload position in Fig.2 B. The process device 1 comprises a cover 13 and a pedestal 14 having metal flange sealings 20 and 21 on opposing surfaces encompassing the outer circumference of the pumping channel 9, see Fig.2B. Therewith in the closed position in Fig.2A the cavities of the process chamber 7 and the pumping channel 9 are closed and the pump slot 8 is formed by a passage between the sidewall 42 of the process chamber, which separates the process chamber from the pumping channel, and the pedestal 14, whereby the flow path is formed between the cover and the pedestal as illustrated with closed arrows. Despite of the fact that forming the flow path between the cover and the pedestal in the area of the process chamber? , the pump slot 8 and the pumping channel 9, is one preferred embodiment of the present invention, as this design enables the easiest service and cleaning access to all these critical parts of the device exposed to the reactive residual gases, it should be mentioned that the invention could be also combined with different designs, e.g. with an alternative pump slot or pump holes 8" positioned stationary in the sidewall 42, as shown in dashed lines with Fig.2B. Further designs of the pump slot can be seen in Fig.5A-C. Instead of a central gas inlet 4, a gas manifold, e.g., a perforated plate (not shown), can be used to facilitate the gas distribution in the distribution chamber 5. A further optimization of the gas distribution in the distribution chamber 5 can be achieved by a gas sideline 40 of a higher flow resistance than the gas shower, which can be provided round the gas shower as shown in Fig.2A. The sideline 40 may lead preferably into the pump slot 8 as shown or alternatively in the pumping channel 9, or in the process chamber 7 near the opening to the pump slot.

The cover 13 and the pedestal 14 also comprise heating elements 29 to preheat and heat both for high temperature processes in a temperature range between 250° to 500°C, respectively 300° to 400°C. Due to the wide sidewise extensions of the pedestal and thereby forming essentially the whole bottom section of the process device, a higher temperature uniformity can be reached in the processing chamber. Additionally, condensation issues in the pump slot and channel can be avoided by a hot bottom area. Therefore, additional heaters 29" can be foreseen within the pedestal as shown exemplarily in Fig.2B. Pressure p3 in the HV-handling chamber 30 can be set considerably lower than the process pressure, e.g., about 10’⁶ mbar, whereas process pressure pi can be set in about the same range for cleaning processes, and p2 in the pumping channel will again be below pi.

Further components from the HV-handling chamber 30, like handler 37, 39, HV- pumping unit 32, 39, as well as pins 22 and power supplies 25, 26, from the processing device 1 can be the same as discussed with the state of the art, e.g., pulsed DC supplies or RF supplies. Also, a combination of different power supply types can be applied for certain processes, e.g., DC and pulsed DC respectively RF or the like.

Fig.3 shows top view of an exemplary MCS whereby the handling chamber and the process device is shown in a section. The MCS 30 contains beside the process device 1, a load-lock chamber 33 with an inner and an outer port which are designed as gatevalves 44, three treatment chambers 34, 35, 36 fitted with respective closures 43, which again can be gate valves, and a separate chamber which is designed as a wafer magazine 41. At least load-lock chamber 33 and treatment chambers 34, 35, 36 will be equipped with respective separate vacuum pumps (not shown), which will be HV- pumps for treatment chambers designed to perform PVD processes. An in- output unit 45 is provided to enter respective process parameters and control the present state of the MCS 30 and its subunits 1, 33-36, 37, 41. The loading state of the chambers and magazine is symbolized by respective wafers 17, whereas chambers 34-36, especially when designed as PVD-chambers and/or etching chambers which are often used in combination with a PE-CVD process device 1 are usually designed to treat only one wafer at a time, whereas magazines and / or heating/degassing chambers (not shown) can accommodate multiple wafers. In the middle of the MCS a handler which is mounted movable linearly (double v-arrow) along a middle y-axis of the MCS, comprising two rotatable vertical axes Al and A2 and a terminal arm 38 designed as or comprises an end effector to lift a wafer from or set a wafer on extendible pins 22 as shown with Fig.lA to 2B.

The process device 1 as shown in Fig.3 comprises two vacuum pumps 12 being coupled via valves 12 and pumping lines 10 from the outside of the MCS to the pumping channel 9. Thereby an evenly radial gas flow over the wafer can be provided in the inner process chamber 7 at pressure pl which is connected via the small circumferential pump slot with the circumferential pumping channel at pressure p2. In common a pressure difference p2 - pi of about 0.1 to about 0.5 mbar caused by the process gas coming in by the gas inlet or gas shower, as fa as provided, and the flow resistance of the small pump slot will suffice to produce such radial flow patterns.

Fig.4A shows an enlargement of the section labeled "s.Fig.4A" in Fig.2A, which shows a vertical design of a circumferential sidewall 42 of the process chamber 7. With that design cavities 18, that is the process chamber 7 and the pumping channel 9 are formed in the cover 13 and closed in the closed state as shown. The passage of the pumping channel 8 is only formed in the closed state of the process device 1.

Fig.4B shows a more complex embodiment with funnel-shaped sidewalls 42 tapering from the process chamber to the pumping slot 8, which here sits in a symmetry plane S of the processing chamber 7. With this design cavities 18 have to be provide in part in the cover 13 and in part in the pedestal 14.

Fig.4C again shows an embodiment with cavities distributed to cover 13 and pedestal 14. With that design however the inner circumference of the process chamber 7 is designed to run together circularly in the direction of the pump slot, which again sits about in the symmetry plane S. Gap size d of the slot 8 which is formed between two parallel surfaces of the cover 13 and the pedestal 14 should be dimensioned as mentioned in the following to confine the plasma to the process chamber 9, i.e., to avoid plasma flashover to the pumping channel 9: 0.5 mm < d < 4 mm and especially from 1 mm < d < 3 mm. These dimensions should be considered for any embodiment of the present invention. Flow resistance can then additionally be adapted by a respective slot length and/or guidance of the slot, e.g., straight as with Figs.4B and 4C or angular as in Fig.4A. Bend or meandering alternatives may be applied where a higher flow resistance should be intended. A straight guidance, however, is less sensitive to particle formation, e.g., due to flow turbulences, and easier to clean.

All embodiments as shown in Fig.4A to 4C and variations thereof, as evident to the expert, can be combined with any other embodiment as discussed above, however it has been found that designs similar or equal to Fig.4C, comprising sidewalls 42 converging continuously towards the pumping slit gave the best, that is the least turbulence flow pattern in the process chamber. Such flow patterns can even be further fostered by positioning the gas shower 6, as far as provided, in a recess of the cover 13 and/or by positioning the wafer 17 in a recess of the pedestal 14 or provide an outer cover ring 45 (dashed lines in Fig.4C) to avoid any discontinuities within the geometry of the process chamber. REFERENCE SIGNS LIST

1,1' process device 30,30' multi chambered system (MCS)

2 gas supply/reservoir 31 handling chamber

3 gas line 32 high vacuum pump

4 gas inlet 33 load-lock chamber

5 gas distribution chamber 34-36 treatment chambers

6 gas shower 37 handler

7,7' process chamber 38 terminal arm/end effector

8 pump slot 39 HV valve

9,9' pumping channel 40 gas side line

10 pumping line 41 wafer magazine

11 pump valve 42 sidewall of the process chamber

12 vacuum pump

43 chamber closure / gate valve

13,13' cover

44 gate valves from load-lock

14,14' pedestal/chuck

45 outer cover ring

15 opposing surface (cover)

46 in- output unit

16 opposing surface (pedestal)

17 substrate/wafer

18 cavity of process chamber

Al, 2 rotational axes

19 cavity of pumping channel

A3 linear drive/lift axis

20,20' sealing (cover) d gap size

21,21' sealing (pedestal)

P_c closing plane

22 pins

23 pedestal drive/lift

25 first power supply

26 second power supply

27 first power line

28 second power line

29 heater

Claims

1. A process device to treat at least one side of a flat substrate under vacuum, the process device (1) comprising: a central process chamber (7), a cover (13) having a gas inlet (4) and extending outward in a closing plane (P_c) with its circumference over an outer diameter of a pumping channel (9), the pumping channel (9) being connectable to one or more vacuum pumps (12), the pumping channel further encompasses at least a major part of the process chamber and is, at least in a closed state of the process chamber, in fluid connection to the process chamber via a circumferential pump slot (8), or circumferentially arranged pump holes (8''); a pedestal (14) to support the flat substrate (17), the pedestal extending outward in a closing plane (P_c) with its outer circumference over an outer diameter of the pumping channel, and being bidirectionally, linearly movable into an open position and into a closed position, to open and close at least the pumping channel.

2. The process device according to claim 1, wherein in the open position the process chamber (7) is open, and in the closed position the process chamber is closed.

3. The process device according to claim 1 or 2, wherein in the open position the pump slot (8) is open, and in the closed position the pump slot is formed providing a fluid connection between opposing surfaces (15, 16) of the cover (13) and the pedestal (14) from the process chamber to the pumping channel.

4. The process device according to one of the forgoing claims, wherein at least one of the pumping channel (9), the process chamber (7), and/or the pump slot (8) is formed in the closed position by opposing surfaces of the cover and the pedestal (15, 16). The process device according to claim 4, wherein the opposing surfaces (15, 16) at least in the region of the pumping channel (8) and in the region of the process chamber (7) comprise cavities (19, 18) which are open towards the closing plan (P_c) in the open position. The process device according to claim 5, wherein the cavities (18, 19) can be formed completely or in part in one of the pedestal (14) and/or the cover (13). The process device according to claim 6, wherein at least the cavity for the pumping channel (19) is formed in the cover (13).

The process device according to one of the forgoing claims, wherein metallic sealing means (20, 21) are provided on or with opposing surfaces of the cover and the pedestal, the sealing means (20, 21) encompassing the outer circumference of the pumping channel in a ground plane projection. The process device according to claim 8, wherein the sealing means (20, 21) comprise or consist of two metallic flanges. The process device according to one of the forgoing claims, wherein at least one electrode (6, 14) with a power supply (25, 26) is provided to apply a plasma in the process chamber of the processing device. The process device according to claim 10, wherein the electrode is the pedestal and/or a counter electrode in parallel to the pedestal near the top of the process chamber. 12. The process device according to claim 11, wherein the counter electrode is the gas shower or a ring electrode.

13. A multichambered process system (30) comprising a high vacuum handling chamber (31), a high vacuum pump (32) connected to the handling chamber, at least one load lock chamber (33) connected to the handling chamber (31) to load and unload at least one flat substrate (17) into and out of the high vacuum handling chamber, at least one treatment chamber (32, 34, 35, 36) connected to the handling chamber (31), a process device (1) according to one of claims 1 to 12 mounted in the handling chamber (31), at least one handler (36) to load and/or unload a flat substrate from the handling chamber into at least one of the load lock chamber (32) treatment chamber (32, 34, 35, 36) and/or the process device (1), wherein the process device (1) is connected via at least one separate pumping line (10) to a separate vacuum pump (12) and a gas delivery system (2, 3) is connected to the gas inlet of the process device.

14. A multichambered process system according to claim 13 comprising at least two handling chambers (31) each connected to at least one treatment chamber and arranged round a separate robot chamber comprising the handler (36).