Systems having processing chambers and methods for operating such systems

Abstract

A system having a processing chamber with two processing compartments having a vacuum pressure barrier therebetween and a method for operating such a system are presented. The system includes a processing chamber having a first processing compartment and a second processing compartment separated from each other by an intermediate wall, a first gas source, a processing pump, and a transfer apparatus. A slit is formed that penetrates the intermediate wall and provides a flow path for gas from the second processing compartment to the first processing compartment and a transfer path for a substrate from one of the first processing compartment or the second processing compartment to the other of the first processing compartment or the second processing compartment. An ambient pressure within the first processing compartment is less than an ambient pressure within the second processing compartment, and the slit together with the intermediate wall forms a vacuum pressure barrier between the first processing compartment and the second processing compartment.

Description

TECHNICAL FIELD

[0001] The present invention relates to a system comprising a process chamber with two process compartments provided with different process pressures and connected to each other by a vacuum pressure barrier, and to a method of operating such a system. BACKGROUND

[0002] In the solar cell industry, different processes are performed on a substrate for heating or cooling the substrate or for forming isolation trenches, for example for depositing a layer. If the layer is deposited on the substrate by evaporation, this process is performed at low pressure, for example less than 20 PA, in a deposition chamber. Subsequently, the substrate with the applied layer is cooled from the deposition temperature, for example 550 °C, to a lock temperature, for example 450 °C, for moving the substrate away from the deposition chamber for further processing. Usually, this cooling is performed in the same process chamber as the deposition process and, thus, under the same process conditions, i.e. the same low pressure. However, it is better to perform the cooling at a higher pressure, for example 40 PA, because the higher pressure will reduce the re-evaporation of the deposited material from the substrate during cooling. This will reduce the consumption of evaporated material and the contamination of the chamber walls caused by re-evaporation during cooling. In addition, the temperature of the substrate has to be controlled very accurately over the whole substrate area because the re-evaporation should be uniform over the whole substrate in order to reduce the layer thickness variations. The higher pressure further reduces the need for a cooling system because the temperature does not have to be controlled uniformly as at lower pressure due to the reduced re-evaporation. Moreover, the cooling system can be designed simpler because it does not need to be able to collect the re-evaporated material.

[0003] If different process conditions, for example different ambient gases or different pressures, are necessary, usually different process chambers are used for the respective process. The different process chambers are connected to each other by gates, valves or intermediate chambers, wherein each process chamber comprises individual gas inlets for introducing active process gases and / or inactive process gases, for example inert gases, and individual vacuum pumps for setting the respective required pressure. However, due to the necessary equipment and design of the chambers and due to the time-consuming locking of the substrate at the entrance and exit of each chamber, the use of multiple chambers is complex and expensive.

[0004] In the state of the art, continuous in-line systems are known, wherein different process chambers and intermediate chambers divided by chamber walls are connected by short slits or slots. The substrate is transferred from a first process chamber to a second process chamber by a transfer device comprising, for example, rollers or belts on a shaft. However, the pressure separation of the individual chambers in connection with the transfer of the heated or hot substrate from one chamber to the next is challenging. SUMMARY

[0005] It is therefore an object of the present invention to provide a system having two processing compartments in one processing chamber, the two processing compartments having different pressures and having a vacuum pressure barrier therebetween, which overcomes the drawbacks of systems according to the state of the art, and which also includes providing a method for operating such a system.

[0006] This object is solved by the system and method according to the independent claims. Preferred embodiments are given in the dependent claims.

[0007] The system of the invention comprises a processing chamber, and at least a first gas source, a processing pump and a transport device, the processing chamber having a first processing compartment and a second processing compartment adapted to have different pressures. Different processes performed at different ambient pressures can be performed in the first processing compartment and the second processing compartment on a substrate transported by the transport device from one of the first processing compartment or the second processing compartment to the other one of the first processing compartment or the second processing compartment. The ambient pressure within the first processing compartment and the second processing compartment is at least partly adjusted by means of a first gas provided by the first gas source and by means of the processing pump. To this end, the second processing compartment comprises a first gas inlet adapted to introduce the first gas from the first gas source into the second processing compartment, and the first processing compartment comprises a first gas outlet connected to the processing pump, the first gas outlet being adapted to evacuate gas from the first processing compartment. The first gas can be a single gas, e.g. an inert gas like N2, or a composition comprising more than one gas, e.g. an inert gas and a reactive gas.

[0008] The processing chamber comprises a chamber wall separating the interior of the processing chamber from the exterior. The chamber wall is vacuum tight and adapted to provide an internal vacuum in the range from low vacuum to high vacuum, wherein the pressure provided in the second processing compartment, referred to as second pressure, is higher compared to the pressure provided in the first processing compartment, referred to as first pressure. In particular, the pressure within the first processing compartment, referred to as first pressure, can be in the range of 0.05 Pa to 100 Pa, while the second pressure can be 1000 Pa higher than the first pressure. For example, the first pressure can be in the range between 1 Pa and 20 Pa, while the second pressure can be in the range between 20 Pa and 50 Pa. The chamber wall is preferably adapted to be cooled to a temperature in the range from room temperature (about 20 °C) to 60 °C, wherein in this case the system comprises cooling means according to the state of the art. The chamber wall is preferably made of stainless steel.

[0009] The system can further comprise an exhaust pump connected to the second processing compartment. This exhaust pump is mainly used during venting of the processing chamber relying on atmospheric pressure or a pressure much higher than the second pressure, because due to the slit, venting using only the processing pump would take a long time. During processing in the processing chamber, the exhaust pump can help to regulate the second pressure in the second processing compartment. Therefore, the second processing compartment can comprise a second gas outlet connected to the exhaust pump.

[0010] Further, the system can comprise a second gas source for providing a second gas to the first processing compartment. The second gas source can be arranged inside the first processing compartment, e.g. the evaporation source, or can be arranged outside the first processing compartment and connected to the first processing compartment, in particular to the second gas inlet of the first processing compartment. Moreover, the second gas source can also be a combination of a gas source inside the first processing compartment and a gas source outside the first processing compartment. The second gas can be a single gas, e.g. an inert gas like N2or a reactive gas, or a composition comprising more than one gas, e.g. an inert gas and a reactive gas, e.g. CdTe or O2, wherein the different gases can be provided by different gas sources being part of the second gas source.

[0011] The first processing compartment and the second processing compartment are separated from each other by an intermediate wall. That is, the intermediate wall extends from one chamber wall to its opposite chamber wall along a direction different from the direction along which the first processing compartment and the second processing compartment are arranged adjacent to each other. Thus, the intermediate wall divides the processing chamber into the first processing compartment and the second processing compartment. The intermediate wall does not have any door or shutter or valve, but a slit or channel is formed. In embodiments, the intermediate wall is made of a material different from the material of the chamber walls and preferably of a material having a low thermal conductivity, i.e. lower than 40 W / (m-K), and a high thermal stability, i.e. it can withstand high thermal gradients, e.g. up to 550 K, across its extension. For example, the intermediate wall can be made of carbon fiber carbon composite (CFC) or ceramic or glass-ceramic or a combination thereof.

[0012] The slit penetrates the intermediate wall or is arranged adjacent to an opening in the intermediate wall such that it provides a gas path for the gas from the first process compartment to the second process compartment and a transport path for the substrates. The slit allows a portion of the gas to be present within the second process compartment and comprises the first gas inserted into the second process compartment to flow into the first process compartment. The intermediate wall and the at least one slit form a vacuum pressure barrier between the first process compartment and the second process compartment. The cross section of the slit should be formed as small as possible and as long as possible in order to provide a good vacuum pressure barrier. The slit can be formed as a hollow prism extending into the interior of the first process compartment and / or into the interior of the second process compartment. Since the slit is a hollow body with a preferably rectangular cross section, it has walls, preferably four walls, and an open space inside. The dimensions of the slit, in particular the width and the height of the slit, are adapted to the dimensions of the substrates transported through the slit. For example, glass plates used as substrates in the production of solar cells usually have the following dimensions:

[0013] thickness: 0.5 mm to 5 mm, preferably 2 mm to 4 mm, in particular 3.2 mm

[0014] width: 0.6 m to 2 m, in particular 1.2 m

[0015] length: 1 m to 2.6 m, in particular 1.6 m.

[0016] The slit can therefore have the following outer dimensions:

[0017] height: 10 mm to 300 mm

[0018] width: 1.1 m to 1.6 m, in particular 1.3 m

[0019] length: 0.5 m to 4 m, preferably 2 m to 4 m, in particular 3 m,

[0020] and the open space inside the slit can have a cross section of the following dimensions, wherein the open space extends over the entire length of the slit:

[0021] height: 5 mm to 30 mm, in particular 10 mm

[0022] width: 1 m to 1.5 m, in particular 1.25 m.

[0023] The length is the extension of the respective object (substrate, slit or space) in the direction of transport of the substrates by the transport device, wherein the width is the extension of the respective object measured in the substrate transport plane and perpendicular to the length of the object. The thickness or height is the extension of the respective object measured perpendicular to the substrate transport plane, i.e. perpendicular to the length and the width.

[0024] Preferably, the dimensions and form of the slit are essentially uniform throughout its entire length. In embodiments, the length of the slit is longer than half the length of the substrate to be conveyed by the conveying device. In any case, at least one member of the conveying device, for example a shaft with rollers or a belt, is also present within the slit. That is, in the case that the conveying device is formed by a belt, the belt extends through the slit. In the case that the conveying device comprises shafts with rollers, at least one shaft is arranged within the slit, and preferably a plurality of shafts are distributed throughout the length of the slit. The number of shafts within the slit depends on the length of the slit and the properties of the substrate to be conveyed, for example its length and hardness. If the shafts are supported by bearings arranged outside the process chamber on at least one side and the shafts are driven, i.e. rotated, by motors arranged outside the process chamber, two independent kinds of seals are arranged at the shafts at least at one side of the shafts: First, a first vacuum seal for penetrating the chamber wall and for sealing the interior of the process chamber against the atmosphere of the outside environment, and second, a second vacuum seal for penetrating the wall of the slit and for sealing the interior of the slit against the atmosphere in the process compartment in which the slit extends. The second vacuum seal has to withstand high temperatures, but the sealing requirements are lower, since only a small pressure difference has to be sealed. The respective seals are known to the person skilled in the art.

[0025] If the conveying device comprises shafts, in some embodiments the interior of the slit can be divided by plates or bridges arranged between the shafts, so that the rollers of the shafts protrude above the plates or bridges, on which the substrate rests during the conveying. That is, the height of the open space of the slit, which is suitable as a conveying path for the substrate and as a gas path, is greatly reduced with respect to the height of the slit.

[0026] In some embodiments, the slit is heated such that a substrate conveyed through the slit does not cool significantly from the temperature the substrate has in one of the first compartment or the second compartment. If the substrate is conveyed from a first process compartment, for example, in which a layer is evaporatively deposited onto the substrate, to a second process compartment, the substrate has a temperature of 500°C to 600°C when leaving the evaporation unit and cools only 0K to 50K, preferably 0K to 20K, as the substrate is conveyed into the second process compartment in which it further cools to a lock temperature. The lock temperature enables a safe lock process of the substrate leaving the process chamber and can be in the range of room temperature to 500°C, preferably in the range of 400°C to 500°C, and most preferably at 450°C. Preferably, the substrate cools only 10K within the slit. Thus, the system further comprises a heating unit adapted to heat the slit to a desired temperature, for example in the range of 500°C to 600°C. The heating unit is further adapted to provide a good thermal uniformity across the length and width of the slit. The slit is preferably made of a material having a high thermal conductivity, i.e. higher than 80 W / (m K). The slit can for example be made of graphite or ceramic or glass or glass ceramic or combinations thereof.

[0027] In some embodiments, the inventive system further comprises a reduced pressure gas circuit comprising a reduced pressure pump. A first end of the reduced pressure gas circuit is connected to the first opening of the slit or to the first process compartment and a second end of the reduced pressure gas circuit is connected to the first gas inlet or to the third gas inlet as part of the second process compartment. The first opening of the slit is an end of the slit arranged within or adjacent to the first process compartment. The reduced pressure gas circuit is adapted to exhaust a portion of the gas passing through the slit and to introduce this portion of the gas into the second process compartment via the first gas inlet or the third gas inlet.

[0028] If the first opening of the slit is arranged at an opening in the intermediate wall, a gas channel connecting the slit with a third gas outlet of the process chamber is formed in embodiments. This gas channel can be formed as a space between an additional wall and the intermediate wall or can be formed as a space within the intermediate wall. The first end of the reduced pressure circuit is connected to the third gas outlet. A second gas outlet is formed in a chamber wall of the process chamber and allows the portion of the gas flowing through the slit to flow from the first opening of the slit to the reduced pressure circuit via the gas channel.

[0029] By means of the reduced pressure gas circuit, the amount of first gas that needs to be provided by the first gas source can be reduced, since a part of the first gas is recirculated to the second process compartment. Therefore, components of the first gas source, such as a mass flow controller (MFC) for adjusting the amount of first gas provided by the first gas source, can be reduced in size, making said components cheaper. Furthermore, the process pump can be provided with a smaller pump capacity, since less gas has to be evacuated from the first process compartment compared to the prior art. Therefore, the cost of the system and the cost of operating the system can be greatly reduced compared to the prior art.

[0030] The inventive system can be used for all vacuum processes, wherein different ambient pressures are used in the first process compartment and the second process compartment, and wherein the ambient pressure within the first process compartment is smaller than the ambient pressure within the second process compartment and lies in a range between 0.05 Pa and 100 Pa, and wherein the substrate should be processed first in one of the first process compartment or the second process compartment and subsequently in the other one of the first process compartment or the second process compartment. Nevertheless, the processing of the substrate in one of the first process compartment or the second process compartment and in the other one of the first process compartment or the second process compartment can be repeated one or more times, i.e. the substrate can be oscillated between the first process compartment and the second process compartment and processed more than once in each of the first process compartment and the second process compartment. This is for example the case for depositing layers in multiple partial layers in one of the first process compartment or the second process compartment, wherein another processing step is performed in the other one of the first process compartment and the second process compartment between the deposition of two subsequent partial layers.

[0031] The inventive method for operating the inventive system as described above comprises the following steps: providing such a system, introducing a first gas from a first gas source into the second process compartment via the first gas inlet, setting a first pressure within the first process compartment and a second pressure within the second process compartment by means of the process pump, performing a first process on a substrate in the first process compartment, transferring the substrate from the first process compartment to the second process compartment via the slit by means of the transfer device, and performing a second process on the substrate in the second process compartment.

[0032] If the system further comprises an exhaust pump connected to the second process compartment, the second pressure within the second process compartment is also set by means of the exhaust pump. In this case, the first pressure and the second pressure can be set almost independently of each other, wherein the independence is limited only by the effectiveness of the slit as a pressure barrier.

[0033] In some embodiments, the substrate is heated to a first temperature when performing the first process, and the substrate is heated when the substrate is transported through the slit, such that the temperature of the substrate leaving the slit into the second process compartment is at most 0 K to 50 K less than the first temperature. Preferably, the temperature of the substrate leaving the slit is preferably at most 0 K to 20 K less than the first temperature, and most preferably at most 10 K less than the first temperature.

[0034] In some embodiments, a portion of the first gas flowing from the second process compartment via the slit to the first process compartment is evacuated from the first end of the slit or from the first process compartment using a roughing pump via a roughing circuit and introduced into the second process compartment via the first gas inlet or the third gas inlet. In this case, a first amount of the first gas is introduced into the second process compartment via the first gas inlet. A first portion of the gas present in the second process compartment, the first portion being referred to as a second amount, leaves the second process compartment and flows through the slit in the direction to the first process compartment. A first portion of the second amount, referred to as a third amount, is evacuated from the first end of the slit or from the first process compartment by the roughing pump and flows back to the second process compartment through the roughing circuit and is reintroduced into the second process compartment. A second portion of the second amount, referred to as a fourth amount, is added to the gas present in the first process compartment. A first portion of the gas present in the first process compartment, the first portion being referred to as a fifth amount, is evacuated from the first process compartment by the process pump. The first amount to the fifth amount are constant as long as the ambient pressure in the first process compartment and the second process compartment is constant. That is, the first amount to the fifth amount can change relative to each other during the start of the process or the end of the process or during another change of the ambient pressure in one or both of the first process compartment and the second process compartment.

[0035] Although in the description it is described that the substrate is first present in the first process compartment and processed in the first process compartment, then transported into the second process compartment and subsequently present in the second process compartment and processed in the second process compartment, the term "substrate" can also refer to only a portion of the substrate. That is, if a long substrate is processed within the processing chamber, the following can be present at the same point in time: a first portion of one substrate can have been processed in the first process compartment and can now be present in the second process compartment, a second portion of the same substrate can also have been processed in the first process compartment and can now be present within the slit, and a third portion of the same substrate can be processed within the first process compartment. In this case, it is especially important to reduce the temperature drop across the substrate in order to reduce the stress within the substrate and the risk of breaking the substrate. Furthermore, for long substrates, a continuous movement of one substrate within the first process compartment, through the slit, and within the second process compartment is preferred.

[0036] Furthermore, it is possible to process a first substrate within the first process compartment and simultaneously process a second substrate within the second process compartment.

[0037] Although one slit is mentioned in the description, it is still possible to provide two or more slits that penetrate the same intermediate wall, wherein each slit is suitable for providing a transport path for a substrate. Some or all of the slits can be arranged in one plane, for example a horizontal plane, that corresponds to the plane of the substrates during transport, or some or all of the slits can be arranged in different planes, in particular parallel to each other. Furthermore, each slit can have a width of its open space such that only one substrate can pass through the slit. Nonetheless, it is also possible that some or all of the slits have a width of their open space that allows two or more substrates side by side along the width of the slit to pass through the slit.

[0038] Several combinations of embodiments of features of the inventive system or of the inventive method are possible, as long as they do not impede each other.

[0039] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration specific embodiments in which the application can be practiced. It is understood that other embodiments can be utilized and structural or logical changes can be made without departing from the scope of the present application. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present application is defined by the appended claims. The elements of the figures are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 A first embodiment of a system according to the present application is schematically shown, wherein a processing chamber is shown in cross-sectional view.

[0041] Figure 2 An exemplary slit 15 is schematically shown in more detail.

[0042] Figure 3 Dimensions of a slit 15 in plan view are schematically shown.

[0043] Figure 4 A method for operating a system according to the present application is schematically shown.

[0044] Figure 5 A second embodiment of a system according to the present application is schematically shown, wherein the system further comprises a reduced pressure gas circuit.

[0045] Figure 6 Details of a third embodiment of a system according to the present application are schematically shown. DETAILED DESCRIPTION

[0046] Figure 1A first embodiment 100 of a system according to the application is schematically shown. The system 100 comprises a process chamber 10, a first gas source 20, a second gas source 23, a process pump 30, an exhaust pump 31, a transport device 40, a heating unit 50, and a cooling unit 60. The process chamber 10 with its components is shown in a cross-sectional view, wherein the cross-sectional view is a view on the x-z plane of a three-dimensional x-y-z coordinate system. The components of the system 100 are only schematically shown in order to describe their function and the connections to the components of the process chamber 10. Figure 2 and 3 Details of the process chamber 10 are shown in order to explain some dimensions and special features.

[0047] The process chamber 10 comprises chamber walls 101 providing an airtight boundary between the interior of the process chamber 10 and the exterior of the process chamber 10. The chamber walls 101 are made of stainless steel and can be cooled by the cooling unit 60 to a temperature in the range of room temperature to 60°C, which substantially surrounds the process chamber 10 at its exterior. Gate valves 102 are arranged in two of the chamber walls 101, respectively, in order to provide an inlet and an outlet for substrates 200 to be processed within the process chamber 10. The substrates 200 are transported within the process chamber 10 along the x-direction on a substrate transport plane 41 from one gate valve 102 to the other gate valve 102 by the transport device 40. The transport device 40 comprises a rotating shaft with rollers on which the substrates 200 rest.

[0048] The process chamber 10 comprises a first process compartment 11 and a second process compartment 12 separated from each other by an intermediate wall 13. The intermediate wall 13 is made of CFC and has a length or thickness L 13 measured in the x-direction, wherein the length L 13 may be in the range of 1 mm to 20 mm, for example 5 mm. The intermediate wall 13 extends along the y- and z-directions from one chamber wall 101 to its opposite chamber wall 101, while the first and second process compartments 11, 12 are arranged adjacent to each other along the x-direction.

[0049] In the first processing compartment 11, a first treatment is performed on the substrate 200, wherein a second treatment is performed on the substrate 200 in the second processing compartment 12. The first treatment can be, for example, a deposition treatment using the evaporation unit 111. The substrate 200 is kept at a first temperature in the range of 500 °C to 600 °C during the first treatment. The second treatment can be, for example, a cooling treatment of the substrate 200, wherein the substrate 200 is cooled from the first temperature to a second temperature, which is lower than the first temperature and, for example, in the range of room temperature to 500 °C, preferably in the range of 400 °C to 500 °C, and most preferably at 450 °C. The first treatment is performed at a first pressure, and the second treatment is performed at a second pressure, which is higher than the first pressure. By way of example, the first pressure is less than 20 Pa and higher than 1 Pa, and the second pressure is less than 200 Pa and higher than 20 Pa. The second pressure reduces re-evaporation of the material deposited in the first treatment from the substrate 200.

[0050] The second processing compartment 12 comprises a first gas inlet 14, which is adapted to introduce a first gas from a first gas source 20 into the second processing compartment 12. The first gas is preferably an inert gas, such as nitrogen, which does not undergo a chemical reaction with the substrate 200 or layers thereon. The first gas source 20 can comprise a gas container 21 and a mass flow controller 22, which is adapted to adjust the amount of inert gas introduced from the first gas source 20 into the second processing compartment 12. The first processing compartment 11 comprises a first gas outlet 17, which is connected to a process pump 30. A part of the gas present in the first processing compartment 11 during operation of the system 100 can be evacuated via the first gas outlet 17 by the process pump 30. The first processing compartment 11 is provided with a second gas source 23, wherein the second gas source 23 comprises an evaporation unit 111 arranged inside the first processing compartment 11 and a gas source 231 arranged outside the first processing compartment 11. The evaporation unit 111 can be, for example, a CdTe source. The gas source 231 can be, for example, adapted to provide an inert gas, such as nitrogen, and can comprise a gas container 232 and a mass flow controller 233. If the gas provided by the gas source 231 is the same as the first gas, the gas container 232 can be the same as the gas container 21. The gas source 231 can comprise one or more further gas containers and one or more further mass flow controllers for providing a further gas, such as O2, to the first processing compartment. The first processing compartment 11 comprises a second gas inlet 112, which is connected to the gas source 231 and is adapted to introduce the gas from the gas source 231 into the first processing compartment 11. Further, the second processing compartment 12 comprises a second gas outlet 121, which is connected to an exhaust pump 31. Although not shown, the first processing compartment 11 and / or the second processing compartment 12 can comprise further gas inlets for introducing further treatment gases.

[0051] Although the first gas inlet 14 and the second gas inlet 112 are schematically shown as holes in the chamber wall 101, the respective gas inlets can also be formed as gas distributors or showerheads known to the person skilled in the art, wherein the gas inlets can provide a uniform distribution of the respective gas within the first processing compartment 11 or the second processing compartment 12, e.g. along the y-direction, such that the substrates 200 present in the respective processing compartment are in contact with the respective gas.

[0052] The slit 15 is arranged at the intermediate wall 13 adjacent to the opening penetrating the intermediate wall 13 and extends into the second processing compartment 12. The slit 15 allows the substrates 200 to be transferred from the first processing compartment 11 to the second processing compartment 12 using the transfer device 40. In addition, the slit 15 allows a first portion of the total amount of gas present in the second processing compartment 12 to leave the second processing compartment 12 and to at least partially enter the first processing compartment 11 during operation of the system 100. The shape of the slit 15 can be a prism having a rectangular, hexagonal or any other regular or irregular shape with three or more corners in a cross-sectional view in the y-z plane, i.e. in a view perpendicular to the transfer direction of the substrates 200. The shape of the slit 15 can also be a cylinder having a circular, elliptical or other regular or irregular circular shape in a cross-sectional view in the y-z plane. In any case, the slit 15 is a structure having an open space from a first opening 151 connected to the first processing compartment 11 to a second opening 152 connected to the second processing compartment 12. Furthermore, the shape and the dimensions of the slit 15 can vary over its extension along the transfer direction of the substrates 200. For example, the dimensions of the first opening 151 can be larger than the dimensions of the second opening 152. The slit 15 can be formed as a single piece, i.e. a single body, e.g. a pipe, which is fed through the intermediate wall 13. In other embodiments, the slit 15 can be formed as a combination of a body attached to the intermediate wall 13 at a side inside the second compartment 12 and a hole in the intermediate wall 13, wherein the opening inside the body and the hole in the intermediate wall 13 correspond, but can have different dimensions.

[0053] The slit 15 has a length L 15 extending from the first processing compartment 11 to the second processing compartment 12 along the transfer direction of the substrates 200, e.g. along the x-direction in the figure 151 The first opening 151 has a first height h 152 , and the second opening 152 has a second height h 15 , each height being measured along a first direction perpendicular to the length L 151 , and the second opening 152 has a second width w 152 , each width being measured along a second direction perpendicular to the length L 15 , e.g. along the z-direction as Figure 3the y-direction as shown in the middle. The first direction and the second direction perpendicular to the length L 15 may also be reversed. The first height h 151 may be equal to or different from the second height h 152 , and the first width w 151 may be equal to or different from the second width w 152 . Preferably, the first height h 151 and the second height h 152 and the first width w 151 and the second width w 152 are equal. By way of example, the slit 15 can have a length L 15 in the range of 0.5 m to 4 m, e.g. 3 m, a first width w 151 and a second width w 152 in the range of 1 m to 1.5 m, e.g. 1.25 m, and a first height h 151 and a second height h 152 in the range of 5 mm to 30 mm, e.g. 10 mm. The slit 15 has a width w 15 measured in the y-direction and a height h 15 measured in the z-direction, wherein the width w 15 and the height h 15 are the outer dimensions of the slit 15. The width w 15 may be in the range of 1.1 m to 1.6 m, e.g. 1.3 m, and the height h 15 may be in the range of 10 mm to 300 mm, e.g. 200 mm. In the embodiment shown in Figures 1 to 3 the hole in the intermediate wall 13 has the same height and width as the first opening 151.

[0054] If multiple slits 15 are present in the system 100, the slits 15 can be arranged along the intermediate wall 13 in the y-direction and the z-direction depending on the conveying device or the multiple conveying devices. The number of slits 15 is not limited and can be in the range of e.g. 1 and 5. The slits 15 can be arranged next to each other along the y-direction, or above each other along the z-direction with a distance between each other, the distance being measured along the y-direction or the z-direction, respectively. The distance can be in the range of e.g. 5 mm to 300 mm, and the distance between all slits 15 can be equal.

[0055] As can be seen in the figures, the slit 15 can be arranged such that it is curved along its entire length L 15extends within the second process compartment 12. Furthermore, in the embodiment shown in the figures, the first opening 151 of the slit 15 is arranged at the intermediate wall 13. That is, the slit 15 does not reach into the first process compartment 11. However, other arrangements of the slit can be designed, wherein the slit extends into the first process compartment and into the second process compartment, or only into the first process compartment.

[0056] The material of the slit 15 can be freely chosen, but is preferably dependent on the process conditions within the first process compartment 11 and / or the second process compartment 12, especially on the used gas and the temperature of the substrate 200. For example, the material of the slit 15 can be graphite.

[0057] As shown in Figure 1 and 2 , the heating unit 50 can be arranged relative to the slit 15, wherein the heating unit 50 is adapted to heat the slit 15 to a desired temperature. The heating unit 50 is only shown schematically in Figure 1 and can be arranged outside the slit 15 as shown in Figure 2 or inside the slit 15. Figure 2 An exemplary embodiment of the slit 15 is shown in more detail. It can be seen that the slit 15 is formed like a hollow box having an upper side 153 and a lower side 154 separated from each other in cross section by the substrate transport plane 41 and the necessary space for transporting the substrate. The heating unit 50 is arranged above the upper side 153 and below the lower side 154, wherein the heating unit 50 can be formed by different parts independent from each other. Furthermore, the transport device 40 is arranged in the lower part, wherein a bridge 155 is arranged between the individual axes of the transport device 40. The bridge 155 is a part of the lower side 154 of the slit 15 and can be formed by the same material as the slit 15. The bridge 155 is connected to the outer wall of the slit 15 and is essentially at the same temperature as said outer wall. Thus, the bridge 155 is adapted to keep the distance of the upper side 153 of the slit 15 to the lower side 154 of the slit 15 essentially the same along the x-direction and the y-direction throughout the slit 15. Thus, said bridge improves the thermal uniformity within the slit 15.

[0058] According to Figure 4 in combination with Figure 1, a method according to the present application is described. In a first processing step S10, a system according to the present application, e.g. the system 100, is provided. Next, a first gas is introduced into the second processing compartment 12 via the first gas inlet 14 (step S20). In step S30, a first pressure is established within the first processing compartment 11 and a second pressure is established within the second processing compartment 12 by means of the processing pump 30. The second pressure is also established by means of the exhaust pump 31. The first pressure is lower than the second pressure. In this case, the gas flows from the second processing compartment 12 to the first processing compartment 11 via the slit 15. In step S40, a first processing is performed on the substrate 200 in the first processing compartment 11, wherein the substrate 200 is introduced into the first processing compartment before. Subsequently, the substrate 200 is transferred from the first processing compartment 11 to the second processing compartment 12 via the slit 15 by means of the transfer device (step S50). In step S60, a second processing is performed on the substrate 200 in the second processing compartment 12. Upon termination of the second processing, the substrate 200 can be removed from the second processing compartment 12. In all of steps S40 to S60, the substrate 200 can be kept at a desired temperature, which can be different for all or some of these processing steps. As already described, steps S40 to S60 can be performed on one substrate but simultaneously on different portions of the substrate. Preferably, the substrate is moved through the processing chamber, i.e. through the first processing compartment 11, the slit 15 and the second processing compartment 12, at a constant speed.

[0059] Although the system 100 according to the present application is described with respect to a substrate being processed in the first processing compartment 11 and the second processing compartment 12, the system 100 can also be used for processing a substrate in the second processing compartment 12 only. In this case, the first processing compartment 11 is not used. Figure 4 The movement of the substrate from the first processing compartment 11 to the second processing compartment 12 is described, but the substrate can also be moved in the opposite direction, i.e. from the second processing compartment 12 to the first processing compartment 11. The direction of movement depends on the processing performed on the substrate in the first processing compartment 11 and the second processing compartment 12.

[0060] Furthermore, a plurality of substrates can be processed in a continuous manner, i.e. one substrate next to the next. Thus, a first substrate can be processed in the second processing compartment according to step S60, a second substrate can be moved via the slit according to step S50, and a third substrate can be processed in the first processing compartment according to step S40. In particular, the substrates can be moved in a continuous manner by the transfer device.

[0061] Figure 5 A second embodiment 110 of a system according to the present application is shown. The system 110 has the same design principles as the system 100 Figure 1 However, for the sake of clarity, in the following, only the differences between the system 100 and the system 110 are described. Figure 5Some components are not shown in the figure, such as the second gas source 23, the evaporation pump 31, the heating unit 50 and the cooling unit 60. The system 110 further comprises a reduced pressure gas circuit 70 for recovering at least a part of the first gas introduced into the second process compartment 12 through the first gas inlet 14. The reduced pressure gas circuit 70 comprises a reduced pressure pump 71 and can comprise at least one other component 72, such as a filter or a sensor. According to Figure 5 In the embodiment shown in the figure, the first end of the reduced pressure circuit 70 is connected to the third gas outlet 18 which is part of the first process compartment 11 and the second end of the reduced pressure gas circuit 70 is connected to the third gas inlet 19 which is part of the second process compartment 12. However, in other embodiments, the second end of the reduced pressure gas circuit 70 can also be connected to the first gas inlet 14 or to the first gas source 20. The capacity of the reduced pressure pump 71 is provided such that, depending on the capacity of the process pump 30, a desired relationship of the ambient pressure within the first process compartment 11 and the second process compartment 12 is achieved.

[0062] In order to almost completely empty the gas flowing from the second process compartment 12 and entering the first process compartment 11 through the first opening 151 of the slit 15, the third gas outlet 18 is arranged in the x-direction and in the y-direction in the vicinity of the first opening 151 of the slit 15. That is, if the first opening 151 is arranged adjacent to the intermediate wall 13, the third gas outlet 18 is arranged in the x-direction and in the y-direction in the vicinity of the intermediate wall 13. Figure 4 In the system 110 shown in the figure, the intermediate wall 13 is in the vicinity of the intermediate wall 13 in the system 110 shown in the figure. Furthermore, there can be additional means, such as a gas duct extending in the z-direction within the first process compartment 11, for establishing a connection between the first opening 151 and the second gas outlet 18.

[0063] Furthermore, the gas channel 16 can be formed as a space between the additional wall 131 and the intermediate wall 13 or can be formed as a space within the intermediate wall 13, wherein the first opening 151 is connected with the gas channel 16. The design comprising the additional wall 131 is shown in Figure 6 Figure 6 Details of a third embodiment 120 of a system according to the invention are shown. The system 120 has the same design principles as the system 100 of Figure 1 and also comprises similar components as the system 100 according to Figure 5 ​The depressurized gas circuit described in system 110 is a depressurized gas circuit. The gas passage 16 can be formed in any manner, as long as it provides a gas flow connection from the first opening 151 of the slit 15 to the depressurized circuit 70. For this purpose, the gas passage 16 is connected to a third gas outlet 18 disposed in the chamber wall 101 of the processing chamber 10. The gas passage 16 has an inner length measured along the x-direction between the additional wall 131 and the intermediate wall 13, which can be in the range of, for example, 25 mm to 500 mm. Furthermore, the gas passage 16 has a width measured along the y-direction, which can be in the range of, for example, 200 mm to 2000 mm. The width of the gas passage 16 can be related to the width w of the first opening 151 of the slit 15. 151 Same, or can be less than or greater than width w 151 Furthermore, the additional wall 131 may be similar to the intermediate wall 13 extending along the y-direction from one chamber wall to the opposite chamber wall.

[0064] In the following text, according to Figure 5 The method of the present invention for operating systems 110 and 120 is described, wherein the method is described in a normal, stable operating state where there is no startup or shutdown and no other change in state. A first amount V1 of a first gas is introduced from a first gas source 20 into a second processing compartment 12 via a first gas inlet 14. A first volume V of gas is present in the second processing compartment 12. 12 The gas may be a first gas or a composition including the first gas. As the first volume V 12 A portion of the second quantity V2 enters the slit 15 through the second opening 152 and enters the first processing compartment 11 through the first opening 151. A third quantity V3, which is part of the second quantity V2, becomes the second volume V of gas present in the first processing compartment 11. 11 As part of the second volume V2, a fourth volume V4 is discharged by the pressure reducing pump 71 toward the third gas outlet 18, and the fourth volume V4 enters the pressure reducing circuit 70 due to the operation of the pressure reducing pump 71. Assuming no gas loss within the pressure reducing circuit 70, the fourth volume V4 is introduced from the pressure reducing circuit 70 into the second processing compartment 12 via the third gas inlet 19. Since the fourth volume V4 is discharged near the first opening 151 of the slit 15, it has essentially the same composition as the gas in the second processing compartment 12. As part of the second volume V2, the fourth volume V4 is discharged by the pressure reducing pump 71 toward the third gas outlet 18, and enters the pressure reducing circuit 70 due to the operation of the pressure reducing pump 71. 11A fifth amount V5 of the gas which is part of the fourth amount V4 is discharged from the first process compartment 11 via the first gas outlet 17 by means of the process pump 30. Depending on the pump capacity of the pressure reduction pump 71, the process pump 30 has to discharge a much smaller amount of gas, i.e. the fifth amount V5, compared to the state of the art. In addition, the fourth amount V4 of gas is reintroduced into the second process compartment 12, thereby reducing the necessary amount of the first gas, i.e. the first amount VI, which is introduced from the first gas source 20 via the first gas inlet 14.

[0065] For all ranges of values mentioned in the description, the boundary values are included in the ranges.

[0066] The embodiments of the application described in the foregoing description are given by way of example and are not intended to be limiting of the application. Any modification, variation or combination of the embodiments with other devices, methods and materials, as well as any other equivalent arrangements are intended to be included in the scope of the application.

[0067] Reference Signs

[0068] 100, 110, 120 system

[0069] 10 process chamber

[0070] 101 chamber wall

[0071] 102 gate valve

[0072] 11 first process compartment

[0073] 111 evaporation unit

[0074] 112 second gas inlet

[0075] 12 second process compartment

[0076] 121 second gas outlet

[0077] 13 intermediate wall

[0078] 131 additional wall

[0079] 14 first gas inlet

[0080] 15 slit

[0081] 151 first opening

[0082] 152 second opening

[0083] 153 upper side of the slit

[0084] 154 lower side of the slit

[0085] 155 bridge

[0086] 16 gas channel

[0087] 17 first gas outlet

[0088] 18 third gas outlet

[0089] 19 third gas inlet

[0090] 20 first gas source

[0091] 21 gas container

[0092] 22 mass flow controller

[0093] 23 second gas source

[0094] 231 gas source

[0095] 232 gas container

[0096] 233 mass flow controller

[0097] 30 process pump

[0098] 31 exhaust pump

[0099] 40 transport apparatus

[0100] 41 substrate transport plane

[0101] 50 heating unit

[0102] 60 cooling unit

[0103] 70 reduced pressure gas circuit

[0104] 71 reduced pressure pump

[0105] 72 further component

[0106] 200 substrate

[0107] h 15 height of the slit

[0108] h 151 height of the first opening

[0109] h 152 height of the second opening

[0110] L 13 length of the intermediate wall

[0111] L 15 length of the slit

[0112] w 15 width of the slit

[0113] w 151width of the first opening

[0114] w 152 width of the second opening

[0115] V1 first amount of gas

[0116] V 11 second volume of gas

[0117] V 12 first volume of gas

[0118] V2 second amount of gas

[0119] V3 third amount of gas

[0120] V4 fourth amount of gas

[0121] V5 fifth amount of gas

Claims

1. A system (100, 110, 120) having a process chamber (10), a first gas source (20), a process pump (30) and a transfer device (40), the process chamber having chamber walls (101), wherein - an intermediate wall (13) is arranged within the process chamber (10) such that it extends from one of the chamber walls (101) to another of the chamber walls (101), thereby dividing the process chamber (10) into a first process compartment (11) and a second process compartment (12) suitable for having different ambient pressures, - the second process compartment (12) comprises a first gas inlet (14) suitable for introducing a first gas from the first gas source (20) into the second process compartment (12), - a slit (15) penetrates the intermediate wall (13) and provides a gas path for a gas from the second process compartment (12) to the first process compartment (11) and a transfer path for a substrate (200), wherein the transfer device (40) is suitable for transferring the substrate (200) from one of the first process compartment (11) or the second process compartment (12) to the other of the first process compartment (11) or the second process compartment (12) through the slit (15), and wherein at least one member of the transfer device (40) is arranged within the slit (15), - the first process compartment (11) comprises a first gas outlet (17) connected to the process pump (30) suitable for evacuating gas from the first process compartment (11); - the system (100, 110, 120) further comprises a heating unit (50) suitable for heating the slit (15) to a desired temperature; and - the slit (15) is formed like a hollow box having an upper side (153) and a lower side (154) separated from each other in cross-section by a substrate transfer plane (41) and a necessary space for transferring the substrate (200), the heating unit (50) being arranged above the upper side (153) and below the lower side (154).

2. The system (100, 110, 120) according to claim 1, characterized in that - the chamber walls (101) are made of stainless steel, - the system further comprises a cooling unit (60) suitable for cooling the chamber walls (101) to a temperature in the range of room temperature to 60°C, - the intermediate wall (13) is made of a material different from the chamber walls (101) and having a thermal conductivity lower than 40 W / (m-K) and a high thermal stability, - the slit (15) is made of a material having a thermal conductivity higher than 80 W / (m-K), and - the heating unit is suitable for heating the slit (15) to a temperature in the range of 500°C to 600°C.

3. The system (100, 110, 120) according to claim 1 or 2, characterized in that, The system (100, 110, 120) further comprises a pressure reduction gas circuit (70) comprising a pressure reduction pump (71), wherein a first end of the pressure reduction gas circuit (70) is arranged in the vicinity of the first opening (151) of the slit (15) and a second end of the pressure reduction gas circuit (70) is connected to the first gas inlet (14) or to a third gas inlet (19) being part of the second process compartment (12), wherein the pressure reduction gas circuit (70) is adapted to evacuate a portion of the gas flowing from the second process compartment (12) through the slit (15) towards the first process compartment (11) and to introduce this portion of gas into the second process compartment (12).

4. The system (100, 110, 120) according to claim 3, characterized by The first opening (151) of the slit (15) is formed adjacent to an opening in the intermediate wall (13), the process chamber (10) comprises a third gas outlet (18), a gas passage (16) connecting the first opening (151) of the slit (15) with the third gas outlet (18) is formed between an additional wall 131 and the intermediate wall (13), and the first end of the pressure reduction gas circuit (70) is connected to the third gas outlet (18).

5. A method for operating a system (100, 110, 120) according to any one of claims 1 to 4, the method comprising the following steps: a) providing a system (100, 110, 120) according to any one of claims 1 to 4, b) introducing a first gas from the first gas source (20) into the second process compartment (12) via the first gas inlet (14), c) setting a first pressure within the first process compartment (11) and a second pressure within the second process compartment (12) by means of the process pump (30), d) performing a first process on a substrate (200) in the first process compartment (11), e) transferring the substrate (200) from the first process compartment (11) to the second process compartment (12) via the slit (15) by means of the transfer device (40), and f) performing a second process on the substrate (200) in the second process compartment (12).

6. The method according to claim 5, characterized in that - in step d), the substrate (200) is heated to a first temperature, - in step e), the substrate (200) is heated such that the temperature of the substrate (200) leaving the slit (15) into the second process compartment (12) is at a maximum of 50 K less than the first temperature.

7. The method of claim 6, wherein, The first temperature is in the range of 500 °C to 600 °C.

8. The method of claim 6, wherein, The chamber wall (101) is cooled to a temperature in the range of room temperature to 60 °C.

9. The method according to any one of claims 6 to 8, characterized in that, The system (100, 110, 120) is the system according to claim 3 or 4, and the method further comprises the following steps: g) using said underpressure pump (71) via said underpressure gas circuit (70) to evacuate from the first opening (151) of the slit (15) or from the first process compartment (11) a portion of the gas flowing from the second process compartment (12) to the first process compartment (11) via the slit (15), and h) introducing said portion of the gas evacuated in step g) into the second process compartment (12) via said underpressure gas circuit (70) and said first gas inlet (14) or said third gas inlet (19).

Images