WO2016095975A1

WO2016095975A1 - Apparatus and method for coating a substrate with a movable sputter assembly and control over process gas parameters

Info

Publication number: WO2016095975A1
Application number: PCT/EP2014/078056
Authority: WO
Inventors: Daniel Severin; Marcus Bender; Markus Hanika; Ralph Lindenberg
Original assignee: Applied Materials, Inc.
Priority date: 2014-12-16
Filing date: 2014-12-16
Publication date: 2016-06-23
Also published as: CN208791746U; KR20170095362A

Abstract

According to embodiments, an apparatus and a method for coating a substrate are provided. The apparatus includes a vacuum process chamber. The vacuum process chamber includes a gas inlet assembly and a sputter assembly. The gas inlet assembly includes at least one connector for connecting to one or more process gas sources. The sputter assembly includes a sputter source. The sputter assembly is movable in the vacuum process chamber. The apparatus further includes a controller. The controller is configured for controlling, in dependence of a current position of the sputter source in the vacuum process chamber, at least one of: a flow of a process gas introduced through the gas inlet assembly into the vacuum process chamber, a composition of the process gas introduced through the gas inlet assembly into the vacuum process chamber, and a distribution of the process gas introduced through the gas inlet assembly into the vacuum process chamber. The controller may additionally or alternatively be configured for controlling a gas flow pumped out of the vacuum process chamber.

Description

APPARATUS AND METHOD FOR COATING A SUBSTRATE WITH A MOVABLE SPUTTER ASSEMBLY AND CONTROL OVER PROCESS GAS PARAMETERS

FIELD

[0001] The present disclosure relates to an apparatus and a method for coating a substrate in a vacuum process chamber, and more particularly to an apparatus and a method for forming at least one layer of sputtered material on the substrate. Specifically, the apparatus includes a sputter assembly with at least one sputter source for coating the substrate. More specifically, at least some aspects of the present disclosure relate to magnetron sputtering, particularly reactive sputtering or inert sputtering. The target of the at least one sputter source may be, for example, a rotatable cylindrical target.

BACKGROUND

[0002] Forming a layer on a substrate with a high uniformity (i.e., uniform thickness over an extended surface) is an important issue in many technological fields. For example, in the field of thin film transistors (TFTs) thickness uniformity may be the key for reliably manufacturing display metal lines. Furthermore, a uniform layer typically facilitates manufacturing reproducibility.

[0003] One method for forming a layer on a substrate is sputtering, which has developed as a valuable method in diverse manufacturing fields, for example in the fabrication of TFTs. During sputtering, atoms are ejected from the target material by bombardment thereof with energetic particles (e.g., energized ions of an inert or reactive gas). Thereby, the ejected atoms may deposit on the substrate, so that a layer of sputtered material can be formed.

[0004] However, forming a layer by sputtering may compromise high uniformity requirements due to, for example, the geometry of the target and/or the substrate. In particular, uniform layers of sputtered material over extensive substrates may be difficult to achieve due to an irregular spatial distribution of sputtered material. The provision of multiple targets over the substrate may improve layer uniformity. Another option is to rotate the magnet of a magnetron sputter cathode with a constant angular velocity in between certain outer positions and around a zero-position. However, in particular for some applications posing high requirements on layer uniformity, the layer uniformity thereby achieved may not be sufficient. [0005] Therefore, further methods and/or systems for facilitating a highly uniform layer of sputtered material are desirable.

SUMMARY

[0006] According to an embodiment, an apparatus for coating a substrate is provided. The apparatus includes a vacuum process chamber. The vacuum process chamber includes a gas inlet assembly and a sputter assembly. The gas inlet assembly includes at least one connector for connecting to one or more process gas sources. The sputter assembly includes a sputter source. The sputter assembly is movable in the vacuum process chamber. The apparatus further includes a controller. The controller is configured for controlling, in dependence of a current position of the sputter source in the vacuum process chamber, at least one of: a flow of a process gas introduced through the gas inlet assembly into the vacuum process chamber, a composition of the process gas introduced through the gas inlet assembly into the vacuum process chamber, and a distribution of the process gas introduced through the gas inlet assembly into the vacuum process chamber. The controller may additionally or alternatively be configured for controlling a gas flow pumped out of the vacuum process chamber.

[0007] According to another embodiment, a method for coating a substrate in a vacuum chamber is provided. The method includes providing a first process gas environment for a sputter source, and sputtering a sputter material from the sputter source in the first process gas environment, wherein the sputter source is located in a first position relative to the substrate. The method includes moving the sputter source relative to the vacuum chamber. The method further includes providing a second process gas environment for the sputter source which is different from the first process gas environment, and sputtering the sputter material from the sputter source in the second process gas environment, wherein the sputter source is located in a second position relative to the substrate sputtering the sputter material from the sputter source in the second process gas environment, wherein the sputter source is located in a second position relative to the substrate. [0008] Embodiments are also directed to methods for operating the disclosed apparatus. These method steps may be performed manually or automated, e.g. controlled by a computer programmed by appropriate software, by any combination of the two or in any other manner.

[0009] Further advantages, features, aspects and details that can be combined with embodiments described herein are evident from the dependent claims, the description and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] A full and enabling disclosure to one of ordinary skill in the art is set forth more particularly in the remainder of the specification including reference to the accompanying drawings wherein:

Fig. 1 shows a schematic illustration of an apparatus for coating a substrate according to embodiments described herein;

Fig. 2 shows an embodiment of an apparatus for coating a substrate according to embodiments described herein;

Fig. 3 illustrates the working principle of the embodiment of Fig. 2 by a non-limiting example;

Figs. 4-5 show further embodiments of an apparatus for coating a substrate;

Fig. 6 is a schematic block diagram illustrating a method for coating a substrate according to embodiments described herein.

DETAILED DESCRIPTION

[0011] Reference will now be made in detail to the various exemplary embodiments, one or more examples of which are illustrated in each figure. Each example is provided by way of explanation and is not meant as a limitation. For example, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield yet further embodiments. It is intended that the present disclosure includes such modifications and variations.

[0012] Within the following description of the drawings, the same reference numbers refer to the same components. Generally, only the differences with respect to the individual embodiments are described. The structures shown in the drawings are not necessarily depicted true to scale but rather serve the better understanding of the embodiments.

[0013] Fig. 1 shows a top view of an apparatus 100 for coating a substrate 10 in a schematic illustration. The apparatus 100 includes a vacuum process chamber 102. The substrate may be stationary during the coating process in the vacuum process chamber 102, in particular during deposition of a layer onto the substrate 10. The apparatus 100 includes a sputter assembly 110 which includes one or more sputter sources, e.g., sputter sources for sputtering off a rotatable target. The apparatus 100 includes a gas inlet assembly 150. In Fig. 1, the gas inlet assembly 150 includes a gas inlet 154 and a connector 152 for connecting the gas inlet assembly 150 to a process gas source (not shown). The gas inlet assembly 150 may include further gas inlets and/or further connectors. A process gas is introduced through the gas inlet assembly 150 into the vacuum process chamber 102 may be a reactive gas for reactive sputtering or an inert gas for inert sputtering.

[0014] The sputter assembly 110 sputters a sputter material onto the substrate 10 in the position in which it is shown in Fig. 1, and is then moved along a front surface of the substrate in a translational movement as indicated by the dashed arrows and the dashed rectangle symbolizing the sputter assembly 110 at a later point in time. The front surface of the substrate receives the sputter material, and sputtering continues while the sputter assembly is moved along the front surface. A layer of the sputter material or, in the case of reactive sputtering, a layer of a substance including the sputter material and reactants from the process gas, is formed on the front surface of the substrate. The gas inlet assembly 150 and the connector 152 may be moved together with the sputter assembly 110. The process gas may then be provided through the gas inlet assemblyl50 during the entire coating process. Alternatively, the gas inlet assembly 150 may be stationary in the vacuum process chamber 102, and the gas inlet assembly 150 may then include further gas inlets (not shown) arranged in a line in the direction of the translational movement of the sputter assembly 110.

[0015] Due to the translational movement of the sputter assembly 110, a coating with good uniformity will be deposited onto the front surface of the substrate 10 in the sputter process. The translational movement of the sputter assembly 110 means that the chamber geometry in the vicinity of the sputter assembly and/or the objects that the sputter assembly faces (such as the substrate in contrast to components of the vacuum process chamber like chamber walls or shields) may change. A changing environment may have an effect on the sputter process performed by the sputter assembly.

[0016] In the embodiment shown in Fig. 1, the apparatus 100 further includes a controller 190. The controller 190 receives information about the current positon of the sputter assembly 110, in particular about the position of a sputter source or the positions of sputter sources of the sputter assembly 110, as indicated in Fig. 1 by the bold arrow pointing from the sputter assembly 110 to the controller 190. For instance, the information about the current position of the sputter assembly 110 or the sputter source(s) of the sputter assembly 110 may be measured continuously or in certain time intervals, e.g., by sensors, and the results passed to the controller 190. Alternatively, the controller 190 may control the translational movement of the sputter assembly 110, and may thus know the current position of the sputter assembly 110 from the data used for controlling the translational movement. The controller 190 may further derive the position(s) of the sputter source(s) from a reference position of the sputter assembly 110, in particular if the sputter source(s) are arranged in a fixed spatial relationship between each other.

[0017] Based on the information about the current position of the sputter assembly 110 during the sputter process, the controller 190 controls the flow of the process gas through the gas inlet assembly 150 into the vacuum process chamber 102, e.g., by controlling one or more valves (not shown). In particular, the controller 190 may adapt the flow of the process gas, where necessary and depending on the current position of the sputter assembly 110, to maintain a constant working point of the sputter process. Alternatively or additionally, the controller may adapt the composition of the process gas (e.g., by providing a different mixture of gases from process gas sources) and/or adapt the distribution of the process gas (e.g., by introducing more process gas through a particular gas inlet than through another gas inlet).

[0018] For instance, if the sputter assembly 110 is in the position shown with solid lines in Fig. 1, all or some sputter source(s) of the sputter assembly 110 may face chamber components such as walls or shields, while the sputter source(s) of the sputter assembly 110 face the front side of the substrate 10 in the position shown with dashed lines in Fig. 1. Assuming, for exemplification, that reactive sputtering is carried out the process gas may be reacting differently in the two positions shown, and may be absorbed by chamber components and the substrate at different rates (different local effective pumping). Therefore, the controller may, e.g., provide a higher flow of the process gas in one position, e.g. in the first position shown in solid lines, than in the other position. The local gas density at the sputter source(s), in particular at target(s) of the sputter source(s) may be kept constant in this way, leading to a constant erosion rate of the targets and constant deposition rate of sputter material.

[0019] By controlling the process gas parameters such as flow, composition and/or distribution, a more uniform coating of the substrate may be achieved. For reactive sputtering, the stoichiometry may be improved since the working point of the sputter process is kept constant.

[0020] Fig. 2 shows an embodiment of an apparatus 200 for coating a substrate 10. The substrate 10 is attached to a substrate carrier 12. The substrate carrier 12 is guided by a substrate guiding system 270. The substrate guiding system 270 may, e.g., include rollers supporting the substrate carrier 12 from below, and a magnetic guide rail contactlessly guiding the substrate carrier from above. The substrate guiding system 270 shown in Fig. 2 is configured for allowing the substrate carrier 12 and substrate 10 to be transferred into and out of the vacuum process chamber 202 of the apparatus 200 through corresponding gates (not shown) in the side walls of the vacuum process chamber 202.

[0021] The apparatus 200 further includes a sputter assembly 210. The sputter assembly 210 includes a first sputter source 211 with a first rotatable target 212 and a first magnetron 214, and includes a second sputter source 221 with a second rotatable target 222 and a second magnetron 224. The sputter assembly is mounted on a carriage 230.

[0022] The apparatus 200 includes a process gas source 260. The process gas source 260 may include one or more tanks with gases such as argon, xenon, krypton, neon, oxygen, nitrogen, hydrogen and water vapor, and may include a gas manifold for mixing these gases to form a process gas. The apparatus 200 includes gas inlet assembly 250. The gas inlet assembly 250 includes a connector 252 connected with a connection line 262 to the process gas source 260. The gas inlet assembly 250 includes a first gas lance 254, connected to the connector 252 by a first connection line 253, a second gas lance 256, connected to the connector 252 by a second connection line 255, and a third gas lance 258, connected to the connector 252 by a third connection line 257 (see Fig. 3). The first sputter source 211 is arranged between the first gas lance 254 and the second gas lance 256, and the second sputter source 221 is arranged between the second gas lance 256 and the third gas lance 258. The gas inlet assembly 250 is mounted on the carriage 230. [0023] The apparatus 200 includes a vacuum pump system 265, which may include one or more vacuum pumps. In Fig. 2, one vacuum pump connection line 267 is shown, connecting the vacuum pump system 265 to a gas outlet 204 arranged in a front wall of the vacuum process chamber 202. The apparatus 200 may include more than one vacuum pump connection line and more than one gas outlet, e.g., as many vacuum connection lines as gas outlets. Each vacuum pump connection line may be connected to one vacuum pump or several vacuum pump connection lines may be connected to one vacuum pump.

[0024] The apparatus 200 includes a drive system 240 with a drive 245, such as a linear motor. The drive system 240 may include a track, such as rails, on which the carriage 230 can run. The carriage 230, and thus the sputter assembly 210 and the gas inlet assembly 250 mounted thereon, are driven by the drive system 240 to effect a translational movement along and parallel to the substrate guiding system 270. A first shield 282 and a second shield 284 are arranged between the substrate guiding system 270 and the drive system 240, wherein a gap exists between the first shield 282 and the second shield 284 which allows sputter material to pass between the shields onto a front surface of the substrate 10.

[0025] While the sputter material is sputtered off the first rotatable target 212 and off the second rotatable target 222, the carriage 230 is moved at least along the length of the substrate, and particularly also to positions exterior to the substrate 10. In Fig. 2, the sputter assembly 210 is shown with solid lines in a first position where the first sputter source 211 and the second sputter source 221 face the shield 282 outside of a substrate processing region. The dashed arrow in Fig. 2 indicates that the carriage 230 with the sputter assembly 210 and the process gas inlet assembly 250 is moved, and a second position of the carriage 230 and of the components mounted thereon is shown by dashed lines. In the second position, the first sputter source 211 and the second sputter source 221 face the substrate 10 in a substrate processing region.

[0026] The apparatus 200 includes a controller 290. The controller 290 controls the translational movement of the carriage 230, and of the sputter assembly 210 and of the gas inlet assembly 250 mounted thereon. Particularly, the controller 290 controls the drive system 240, specifically the drive 245 to effect the translational movement of the carriage 230 and of the components mounted thereon, as indicated by the line connecting the controller 290 and the drive 245 in Fig. 2. Since the controller 290 controls the translational movement, the controller 290 possesses information about the current positions of the carriage 230, of the first sputter source 211 with first rotatable target 212, of the second sputter source 221 with second rotatable target 222, and of the gas lances 254, 256 and 258. The controller 290 may also possess information about the position of the gas outlet 204.

[0027] Based on the positional information about the sputter assembly 210 and/or about the gas inlet assembly 250, the controller 290 controls properties of the process gas supply and of gas evacuation from the vacuum process chamber, i.e., the controller controls the process gas parameters.

[0028] The controller 290 may control the process gas source 260, as indicated by the line connecting the process gas source 260 and the controller 290 in Fig. 2, wherein the composition of the process gas may be controlled by the controller 290. For instance, the controller 290 may control in what ratio different gases contained in the process gas source 260 are mixed to form the current process gas composition. The process gas is conducted from the process gas source 260 to the connector 252 by the connection line 262. The controller 290 may control the total flow of the process gas to the sputter assembly 210, for instance by regulating the flow through the connection line 262. The regulation may be done by a valve in the connection line 262 or in the connector 252 or in a similar way. The controller 290 may further control the distribution of the process gas. That means, the controller 290 may control the partial flows of the process gas through the individual gas inlets, such as the gas lances 254, 256 and 258 shown in Fig. 2. The controller may control the partial flows, e.g., by individual valves in the connection lines 253, 255, 257 (see Fig. 3) or by a distribution system in the connector 252.

[0029] Further, the controller may control the pumping system 265 as indicated by the line connecting the controller 290 and the vacuum pumping system 265 in Fig. 2. The controller may control the total flow of gas pumped out of the vacuum process chamber 202, and may control the distribution of partial flows pumped out of each gas outlet if there are more than one gas outlets. The controller may directly control the vacuum pump(s) of the vacuum pumping system 265 or may control regulating valves which may be arranged, e.g., in the vacuum pump connection line 267 or at the gas outlets such as gas outlet 204.

[0030] Fig. 3 schematically illustrates an example of the control exercised by the controller 290 during the sputter process. When the sputter assembly 210, in particular the first sputter source 211 and the second sputter source 221, move(s) from the left to the right in Fig. 3 while sputtering is performed, the sputter assembly 210 will move from a zone outside of a processing zone P into the processing zone P, where the sputter assembly 210 faces the substrate 10, and again into a zone outside of the processing zone P, where the sputter assembly 210 faces other components of the vacuum process chamber, e.g. shields 282 and 284 shown in Fig. 3, or chamber walls or the like. In Figs. 2 and 3, the processing zone P is contained in the gap between the shields 282 and 284.

[0031] In the example shown in Fig. 3, the controller 290 adapts the total flow F of the process gas delivered through the connection line 262 to the gas inlet assembly 250 based on the position x of the sputter assembly 210, and adapts the distribution of the process gas, i.e., the partial flows through connection lines 253, 255 and 257 to the individual gas lances 254, 256 and 258, depending on the position of the gas lances or of the sputter sources. For instance, the total flow F may be higher in a first exterior zone El where none of the sputter sources 211, 221 face the substrate, may decrease in a first transition zone Tl where the components of the sputter assembly 210 and of the gas inlet assembly 250 begin to enter into the processing zone P, may stay constant in a central zone C where all of these components (shown in dashed lines in Fig. 3) are in the processing zone P and face the substrate 10, and may increase in a second transition zone T2 where the components of the sputter assembly 210 and of the gas inlet assembly 250 begin to exit out of the processing zone P, and, in a second exterior zone E2 where none of the sputter sources 211, 221 face the substrate, may be at the same value again as in the first exterior zone El.

[0032] In the first transition zone Tl and in the second transition zone T2, the controller may adapt the distribution of the process gas. For instance, the controller may control the gas inlet assembly 250 to deliver less process gas through connection line 257 to the gas lance 258 than through the connection line 253 to the gas lance 254 and through the connection line 255 to the gas lance 256 in the position of the carriage 230 and sputter assembly 210 shown in Fig. 3 with solid lines. When the carriage 230 with the sputter assembly 210 and the gas inlet assembly 250 mounted thereon moves further to the right in Fig. 3, the controller 290 may then adapt the distribution of the process gas in the transition zone Tl by decreasing the partial flow through the connection line 255 once the gas lance 256 enters into the processing zone P, and then decrease the partial flow through the connection line 253 as the gas lance 254 enters the processing zone P. In the transition zone T2, the partial flows may be increased accordingly in the same order. [0033] The controller 290 may include a memory section storing a gas parameter profile as exemplarily shown in Fig. 3. While the carriage 230 moves through the vacuum process chamber in a translational movement and while the sputter assembly 210 is sputtering, the controller may adapt the process gas parameters by values taken from the gas parameter profile.

[0034] The control exercised by the controller 290 as illustrated in Fig. 3 is only exemplary and not to be understood as limiting. In particular, the gas parameter profile may be more complex and include control information about the total gas flow, the distribution of the process gas and/or the composition of the process gas based on the current positions of the components of the sputter assembly and/or of the gas inlet assembly. Moreover, the control may depend on further aspects of the chamber geometry, such as the shape and proximity of the chamber walls or of other components of the vacuum process chamber and/or the position(s) of the vacuum outlet(s) through which one or more vacuum pumps evacuate the interior volume of the vacuum process chamber. The corresponding control information, possibly stored in one or more gas parameter profiles, enables the controller to maintain a working point of the sputter process constant throughout the sputter process. The controller may additionally vary the process gas parameters or other parameters in a pre-sputter process which takes place before the sputter process. The control of the pre-sputter process may be independent of position, and pre- sputtering may be carried out in a fixed position such as in the exterior zone El.

[0035] Maintaining the working point of the sputter process constant serves to increase the uniformity of the coating sputtered onto the substrate. The combination of the moving sputter source(s) and the control over how the process gas is introduced into the vacuum process chamber is believed to lead to a very uniform coating result. Further, movement of the sputter source(s) allows for using a lesser number of sputter sources as compared to a static arrangement of the sputter sources in the vacuum process chamber. This may be particularly advantageous where the target material that is sputtered onto the substrate is expensive. In the case of reactive sputtering using, e.g., reactive gases such as oxygen and nitrogen, a stable working point positively influences the stoichiometry of the growing layer.

[0036] Embodiments of the present disclosure facilitate formation of layers on a substrate, the layers having a high quality. In particular, the thickness of the deposited layer on the substrate may be highly uniform throughout the whole substrate. Furthermore, a high homogeneity of the layer is facilitated (e.g., in terms of characteristics such as structure of a grown crystal, specific resistance, and/or layer stress). For instance, embodiments of the present disclosure may be advantageous for forming metalized layers in the production of TFTs (e.g., for the manufacturing of TFT-LCD displays) since, therein, the signal delay is dependent on the thickness of the layer, so that thickness non-uniformity might result in pixels that are energized at slightly different times. Moreover, embodiments of the present disclosure may be advantageous for forming layers that are subsequently etched, since uniformity of layer thickness facilitates achieving the same results at different positions of the formed layer.

[0037] Fig. 4 shows a further embodiment of an apparatus 300 for coating a substrate 10. The apparatus 300 includes a sputter assembly 310 which includes at least one sputter source. The apparatus 300 and/or the sputter assembly 310 may have the same or similar properties as the apparatus and sputter assembly described herein with respect to Figs. 1, 2 and 3. The apparatus 300 may include a controller 390, which may have any of the properties of the controller described with respect to Figs. 1, 2 and 3. The controller 390 is configured to control a power source 360 connected to the sputter assembly 310 via electrical connection line 362. Particularly, the controller is configured for controlling, in dependence of a current position of the sputter assembly 310 or of the at least one sputter source of the sputter assembly 310, the power applied to the at least one sputter source by the power source 360. Therein, the power may be controlled by the controller 390 in addition to controlling the process gas parameters as described herein.

[0038] In the embodiment shown in Fig. 5, an apparatus 400 for coating a substrate 10 includes a controller 490 which can perform all the functions of the controller described with respect to Figs. 2 and 3. In addition, the controller controls a power source 460. The power source 460 is connected to a power distribution system 450, in particular to a power connector 452, by an electrical connection line 462. The power connector 452 is connected to the first sputter source 211 via electrical connection line 453, and is connected to the second sputter source 221 via electrical connection line 455. The controller 490 controls the power applied to the first sputter source 211 and controls the power applied to the second sputter source 221 based on the current positions of the first sputter source 211 and of the second sputter source 221. For instance, in the position of the carriage 230 and the positions of the first sputter source 211 and of the second sputter source 221 shown with solid lines in Fig. 5, the controller 490 may control the power applied to the sputter sources to be higher than in the positions shown with dashed lines in Fig. 5. The controller may include a power profile saved in a memory section, and may access the power profile depending on the position of the sputter assembly 210 or of the sputter sources to control the power applied to the sputter sources.

[0039] In this way, by controlling process gas parameters and power parameters, the working point of the sputter process may be stabilized and kept constant even better, leading to an increased uniformity of a layer that is sputtered onto a front surface of the substrate.

[0040] According to an embodiment that can be combined with any of the embodiments described herein, an apparatus for coating a substrate is provided. The substrate may be a TFT substrate or a wafer. The substrate may be a glass substrate, polymer substrate or semiconductor substrate. The substrate may be a larger area substrate, e.g., a large area substrate of GEN 6, GEN 7, GEN 7.5, GEN 8, GEN 8.5, GEN 10 or higher. The dimensions of the substrate may be, for instance, larger or equal to 1100 mm x 1250 mm, larger or equal to 1500 mm x 1800 mm, larger or equal to 2160 mm x 2460 mm, larger or equal to 2200 mm x 2500 mm, or even larger or equal to 2880 mm x 3130 mm. The apparatus may be a coating installation for coating such substrates, in particular for sputtering one or more layers of sputter material onto such substrates. The apparatus may include one or several process chambers, one or more transfer chambers, one or more load lock chambers, one or more swing modules, and/or one or more rotation modules. The chambers and modules of the apparatus may be sized to accommodate the substrates described herein. Therein, the substrates may be transferred through the apparatus in upright format, meaning that the shorter side is parallel to a transfer direction of the substrate through the apparatus. In this case, the footprint of the apparatus may be smaller than in the other option where the substrates are transferred in landscape format, meaning that the longer side is parallel to the transfer direction.

[0041] The apparatus includes a vacuum process chamber. The vacuum process chamber may be connected to a vacuum pump system for evacuating the vacuum process chamber. The vacuum process chamber and the vacuum pump system may be configured for providing a vacuum environment in the vacuum process chamber. The term "vacuum" within the present application refers to a pressure below 10^" mbar (such as, but not limited to, approximately 10^" mbar, as the case may be when a process gas flows within the vacuum process chamber) or, more specifically, a pressure below 10^" mbar (such as, but not limited to, approximately 10^"5 mbar, as the case may be when no process gas flows within the vacuum process chamber). The vacuum process chamber may include vacuum process chamber walls. The vacuum process chamber may include a gate or gates for introducing the substrate into the vacuum process chamber and/or for transferring the substrate out of the vacuum process chamber. The gate(s) may be formed in at least one of the vacuum process chamber walls, such as in one or more side walls. The gate(s) may include a gate valve or gate valves for connecting vacuum tightly to a neighboring chamber or neighboring module.

[0042] The vacuum process chamber includes a sputter assembly. The sputter assembly includes a sputter source. The sputter source may include a target, in particular a rotatable target or a planar target. The target may include or consist of Al, Mo, Ti, Cu, ΓΓΌ, IZO, IGZO, W, Si, Nb, or alloys or compositions thereof. The sputter source may include a magnetron assembly, particularly a magnetron assembly arranged inside of a rotatable target of the sputter source. The magnetron assembly may have a fixed orientation or may be configured to perform an oscillating movement.

[0043] The sputter source may be a first sputter source of the sputter assembly, and the sputter assembly may include N further sputter sources, wherein N is in the range from 1 to 20, such as in the range from 1 to 10. For instance, the sputter assembly may include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more further sputter sources. The further sputter source(s), e.g., second, third, fourth etc. sputter sources, may be of the same type as the first sputter source. The total number of sputter sources may be N+l, and the sputter sources may be arranged along a line or in a bow. The sputter sources may be arranged with regular spaces between the sputter sources or may be arranged with varying spaces between the sputter sources. The sputter sources may form a sputter source array.

[0044] The vacuum process chamber includes a gas inlet assembly. The gas inlet assembly includes at least one connector for connecting to one or more process gas sources. The apparatus may include the one or more process gas sources and/or may include one or more connection lines for connecting the one or more process gas sources to the at least one connector of the gas inlet assembly, e.g., one or more pipes or tubes. A process gas or process gases may be contained in the one or more process gas sources, e.g., process gas(es) for reactive sputtering or process gas(es) for inert sputtering. Examples of a process gas for reactive sputtering are 0₂, N₂, H₂, H₂0 or mixtures thereof. Examples of a process gas for inert sputtering are Ar, Xe, Kr, Ne or mixtures thereof. [0045] The gas inlet assembly may include M gas inlets for introducing the process gas into the vacuum process chamber, wherein M is in the range from 1 to 30, particularly in the range from 2 to 20. The number M of gas inlets may be related to the number N' of sputter sources by the relation M=N'+1, wherein N' is 1 or is N+l with N as specified above, or by the relation M=N'-1, wherein N' is N+l with N as specified above. The gas inlets may be arranged such that there is one sputter source between the process gas flows exiting into the vacuum process chamber from every pair of gas inlets. The gas inlets may be arranged such that, for each gas inlet, the process gas flow exiting into the vacuum process chamber from a particular gas inlet is directed between a different pair of sputter sources. The gas inlets may be arranged such that there is one sputter source between every pair of gas inlets. The gas inlets may be arranged such that there is one gas inlet between every pair of sputter sources. The gas inlets may be gas lances. The gas inlets are in fluid connection with the at least one connector, e.g., by a system of pipes or tubes.

[0046] The vacuum process chamber may include one or more gas outlets, such as L gas outlets, wherein L is in the range of 1 to 10. The one or more gas outlets may be configured for connection with a vacuum pump system including one or more vacuum pumps. The one or more gas outlets may be arranged in a chamber wall or in chamber walls, e.g., in the front wall or the back wall of the vacuum process chamber. The apparatus may include the vacuum pump system, and may particularly include one or more vacuum pumps connected to the one or more gas outlets.

[0047] According to embodiments described herein, the sputter assembly is movable in the vacuum process chamber. Particularly, the sputter assembly may be movable relative to the vacuum chamber, specifically relative to the vacuum process chamber wall(s). The sputter assembly may be movable relative to the substrate, when a substrate is loaded in the vacuum process chamber. The sputter assembly may be movable in a translational movement. The translational movement may be parallel to a substrate surface of the substrate that is coated. The translational movement may be parallel to one or more chamber walls, e.g., parallel to a front wall and/or a back wall of the vacuum process chamber. The translational movement may be a continuous motion, in particular a uniform motion, i.e., a motion with constant speed, at least in a processing zone as described herein.

[0048] The apparatus may include a drive system coupled to the sputter assembly, wherein the drive system is configured for effecting a translational movement of the sputter assembly. The sputter assembly, and particularly the sputter source(s) of the sputter assembly, may be mounted on a carriage. The carriage may be movable in a translational movement. The apparatus may include a track, e.g., a rail system, for supporting and moving the carriage thereon. The apparatus may include a drive system coupled to the carriage of the sputter assembly, wherein the drive system is configured for effecting the translational movement of the carriage.

[0049] The gas inlet assembly may be movable together with the sputter assembly. Particularly, the gas inlet assembly and the sputter assembly may be mounted on the carriage together. Connection lines, such as pipes or tubes, for connecting the at least one connector to the one or more process gas sources, may be flexible or flexible at least in a portion thereof. The connection lines for connecting the at least one connector to the one or more process gas sources may thus react to moving of the gas inlet assembly by bending. Alternatively, the gas inlet assembly, and particularly the gas inlet or the gas inlets of the gas inlet assembly, may be fixedly arranged in the vacuum process chamber.

[0050] The apparatus, particularly the vacuum process chamber, may include a substrate guiding system arranged in the vacuum process chamber. The substrate guiding system may be arranged and oriented for supporting the substrate during coating. The substrate guiding system may be arranged for moving the substrate into and out of the vacuum process chamber, e.g., through one or more gates in side walls of the vacuum process chamber. The substrate guiding system may include a track for supporting the substrate or a substrate carrier holding the substrate, e.g., an assembly of rollers, and/or a track for guiding the substrate/substrate carrier, e.g., a magnetic rail interacting with the substrate carrier. The sputter assembly, particularly the carriage, if present, may be movable along the substrate guiding system. In the case in which the gas inlet assembly is fixedly arranged in the vacuum process chamber, the sputter assembly, and particularly the carriage, may be arranged between the gas inlet assembly and the substrate guiding system.

[0051] The vacuum process chamber may include a processing zone. The processing zone may be at least as wide as the dimension of the substrate that is parallel to a transfer direction of the substrate in the vacuum process chamber, and may be at least as high as the dimension of the substrate that is perpendicular to the transfer direction of the substrate in the vacuum process chamber. The vacuum process chamber may include shields. The processing zone may be defined by, or contained in, a gap between the shields. The shields may be arranged at the substrate guiding system, for shielding the substrate or a substrate carrier during coating. The vacuum process chamber may include at least one non-processing zone outside of the processing zone, such as two non-processing zones, one to each side of the processing zone. The non-processing zones may be at least as wide as the sputter assembly or the carriage. The sputter assembly may be movable at least over the width of the processing zone. The sputter assembly may additionally be movable into or over the at least one non-processing zone.

[0052] The apparatus may further include a controller. According to an embodiment which can be combined with any of the embodiments described herein, the controller is configured for controlling process gas parameters in dependence of a current position of the sputter source in the vacuum process chamber, for instance at least one of: a total process gas flow introduced through the gas inlet assembly into the vacuum process chamber, a composition of the process gas introduced through the gas inlet assembly into the vacuum process chamber, and a distribution of the process gas introduced through the gas inlet assembly into the vacuum process chamber. Control of the distribution may include control of the partial process gas flows that flow from gas inlets of the gas inlet assembly into the vacuum process chamber.

[0053] According to an embodiment which can be combined with any of the embodiments described herein, the gas flow pumped out of the vacuum process chamber may also belong to the process gas parameters. In dependence of a current position of the sputter source in the vacuum process chamber, the controller may, alternatively or additionally to controlling the process gas parameters relating to the introduction of the process gas into the vacuum process chamber, control the gas flow pumped out of the vacuum process chamber, including controlling the total gas flow pumped out of the vacuum process chamber and/or controlling the distribution of partial gas flows pumped out of the process gas chamber, particularly through the one or more gas outlets. The controller may, e.g., control the pumping speed and/or the throughput of gas pumped out of the vacuum process chamber. The controller may control the vacuum pump system, particularly the one or more vacuum pumps, to control the gas flow pumped out of the vacuum process chamber. The controller may control the pumping speed and/or throughput at the one or more gas outlets or at the inlet(s) of the one or more vacuum pumps. The controller may exercise direct control over the vacuum pumps or may control regulating valves, e.g., one or more regulating valves at the outlet(s) of the vacuum process chamber. [0054] The controller may be configured to control at least one of the process gas parameters (such as the total process gas flow, the composition of the process gas, the distribution of the process gas and/or the gas flow pumped out of the vacuum process chamber) in dependence of the current position(s) of at least one of the following components of the apparatus: the N further sputter sources, where N is as described hereinabove, the carriage, and one or more gas inlets of the gas inlet assembly. The controller may be configured for controlling at least one of the total process gas flow, the composition of the process gas and the distribution of the process gas flowing through the M gas inlets in dependence of the position of the M gas inlets, where M is as described hereinabove, and/or in dependence of the position(s) of the sputter source(s). Total process gas flow, composition of the process gas and distribution of the process gas introduced into the vacuum process chamber will be referred to as process gas inlet parameters herein, and the total gas flow pumped out of the vacuum process chamber and the distribution of the partial gas flows pumped out of the vacuum process chamber will be referred to as process gas outlet parameters. These parameters are commonly subsumed under the term "process gas parameters". The controller may control the process gas outlet parameters in dependence of the position(s) of the gas outlet(s) of the vacuum process chamber.

[0055] The controller may adapt at least one of the process gas parameters based on the current position of the sputter source(s) and/or gas inlet(s). The current position of the sputter source(s) and/or of the gas inlet(s) may be defined relative to the substrate guiding system, shields, vacuum outlet(s) or chamber walls of the vacuum process chamber, or any other component of the vacuum process chamber that is fixedly installed in the vacuum process chamber. If a substrate is present in the vacuum process chamber for receiving a coating, the current position(s) may be determined with respect to the substrate.

[0056] The controller may be configured for adapting at least one of the process gas parameters continuously, particularly when the sputter assembly is moved continuously while sputter material is sputtered from the sputter source(s) of the sputter assembly. Therein, "continuously adapting" does not exclude that the at least one process gas parameter may be constant over a range of positions of the sputter source(s) and/or gas inlet(s), but at least one of the process gas parameters is altered at least once. The adaptation takes place during the sputter process. The controller may further be configured to adapt at least one of the process gas parameters during a pre-sputter process, independently of the position where the pre- sputter process takes place. [0057] The controller may be coupled to the drive system for controlling the translational movement of the sputter assembly. The controller may be configured for acquiring information about the position of the sputter assembly, and particularly about the positions of the components of the sputter assembly or of the gas inlet assembly as described herein. This information may be acquired by sensors or other feedback equipment. Alternatively, the controller may possess this information already, in particular if the controller is controlling the movement of the sputter assembly, such as by the drive system.

[0058] The controller may include a memory section for storing a gas parameter profile. The gas parameter profile may include control information about the gas parameters in dependence of the position of the sputter assembly, of the components of the sputter assembly such as the gas outlet(s), and/or of the gas inlet(s) of the gas inlet assembly. The controller may apply the control information of the gas parameter profile based on the information that the controller has or acquires about the current position of said components of the apparatus, and control the gas parameters accordingly. The controller may control valves, gas distribution systems, gas manifolds and/or pumping systems to regulate the gas parameters, e.g., as described herein with respect to Figs. 1 to 3. The controller may be configured to control the gas parameters to maintain the working point of the sputter process stable. The controller may accordingly adapt the process gas environment by regulating the process gas parameters, and keep the local process conditions at the target(s) constant.

[0059] The gas parameter profile, and the control information contained therein, may depend on further particularities of the geometry of the vacuum process chamber, for instance on the current relative position between the one or more vacuum outlets and the sputter assembly/the sputter source(s). The chamber geometry along the motional path of the sputter assembly may additionally or alternatively change, e.g., due to the form of the chamber walls or the presence or absence of additional components that may confine or influence the sputter environment. The gas parameter profile may reflect any such changes of the chamber geometry in that the control information allows maintaining the working point of the sputter process even under these changing circumstances.

[0060] The apparatus may further include a power source for applying power to the sputter source(s). In addition to controlling the gas parameters, the controller may be configured for controlling, in dependence of the current position of the sputter assembly or of the sputter source(s) in the vacuum process chamber, the power applied to the sputter source(s) by the power source. The controller may include a memory section containing at least one power profile as a function of a position of the sputter source or positions of the sputter sources in the vacuum chamber. The controller may be configured to access the power profile(s) to determine the power applied to the sputter source(s) in dependence of the position of the sputter source(s) in the vacuum chamber. The power profile(s) may be pre-determined, e.g., pre-calculated. The controller may be configured for controlling the power applied to the sputter source and/or to N further sputter sources, wherein N is as described hereinabove.

[0061] According to an embodiment, schematically illustrated in Fig. 6, a method 600 for coating a substrate in a vacuum chamber is provided. The method includes providing a first process gas environment for a sputter source, and sputtering a sputter material from the sputter source in the first process gas environment, wherein the sputter source is located in a first position relative to the substrate, as indicated by reference sign 610 in Fig. 6. The method includes moving the sputter source relative to the vacuum chamber, as indicated by reference sign 620 in Fig. 6. The method further includes providing a second process gas environment for the sputter source which is different from the first process gas environment, and sputtering the sputter material from the sputter source in the second process gas environment, wherein the sputter source is located in a second position relative to the substrate, as indicated by reference sign 630 in Fig. 6.

[0062] The first process gas environment and the second process gas environment may be such that the local sputter conditions at the target(s) of the sputter source(s) stay constant. In other words, the working point of the sputter process may be maintained in the first and second position, and particularly also in any positions therebetween. The sputter source may be moved, e.g., continuously and/or uniformly moved, while the sputter material is sputtered. The process gas environment of the sputter source may accordingly adapted based on the current position of the sputter source relative to the substrate or relative to any fixed components of the vacuum process chamber as described herein, such as the substrate guiding system. The process gas environment may be adapted continuously in harmony with a continuous translational movement of the sputter assembly, of the sputter source(s) and/or of gas inlets of a gas inlet assembly as described herein.

[0063] The first process gas environment may be determined by a first set of process gas parameters. The first set of process gas parameters may include at least one of the following: a first process gas composition, a first total inward process gas flow into the first process gas environment, a first distribution of partial inward process gas flows into the first process gas environment, a first total outward gas flow out of the first process gas environment, and a first distribution of partial outward gas flows out of the first process gas environment. The second process gas environment may be determined by a second set of process gas parameters. The second set of process gas parameters may include at least one of the following: a second process gas composition, a second total inward process gas flow into the second process gas environment, a second distribution of partial inward process gas flows into the second process gas environment, a second total outward gas flow out of the second process gas environment, and a second distribution of partial outward gas flows out of the second process gas environment. The second process gas environment may be different from the first process gas environment in that at least one of the following holds: the second gas composition may be different from the first gas composition; the second total inward process gas flow may be different from the first total inward process gas flow; the second distribution of partial inward process gas flows may be different from the first distribution of partial inward process gas flows; the second total outward gas flow may be different from the first total outward gas flow; and the second distribution of partial outward gas flows may be different from the first distribution of partial outward gas flows.

[0064] At a first instant in time or during a first period of time, the first process gas environment may include a first process gas composition in a first amount and in a first distribution. The method may include controlling the total inward process gas flow and/or the total outward gas flow to provide the first amount of process gas in the first processing environment at the first instant in time or during the first period of time. The method may include controlling the first process gas composition by mixing gases in a particular relation, e.g., a relation expressed in terms of volume percentages of the gases. The method may include controlling the first distribution of the process gas in the first process gas environment at the first instant in time or during the first period of time by controlling the partial inward flows of the process gas through gas inlets into the vacuum process chamber and/or by controlling the partial outward flows of gas through gas outlets of the vacuum process chamber. At a second instant in time or during a second period of time, the second process gas environment may include a second process gas composition in a second amount and in a second distribution. The second amount, the second process gas composition, and the second distribution of the process gas in the second process gas environment at the second instant in time or during the second period of time may be controlled as described herein with respect to the first amount, first process gas composition and first distribution. The second gas composition may be different from the first gas composition. Alternatively or additionally, the second amount may be different from the first amount. Alternatively or additionally, the first distribution may be different from the second distribution.

[0065] The first process gas environment provided at the first position and the second process gas environment provided at the second position are selected to maintain the working point of sputtering the sputter material constant. The process gas environment may be continuously adapted based on the current position of the sputter source(s) and/or of gas inlets of the gas inlet assembly to maintain the working point of the sputter process stable.

[0066] The first process gas environment may be provided to the sputter source and to N further sputter sources, wherein N may be as described herein. The second process gas environment may be provided to the sputter source and to the N further sputter sources. Gas inlets, such as M gas inlets of a gas inlet assembly described herein, may be used to deliver the process gas and create the first process gas environment at the first position, the second process gas environment at the second position, or any other process gas environment at any position of the sputter source(s).

[0067] The sputter process of the method for coating a substrate as described herein may include performing any of the functions of the components of the apparatus for coating a substrate according to embodiments described herein. Further embodiments are directed to the use of an apparatus as described herein for coating a substrate. The use of the apparatus may include one, several or all of the features of the method described herein, wherein corresponding components of the apparatus are used to perform the sputter process.

[0068] At least some aspects of the present disclosure particularly relate to substrate coating technology solutions involving equipment, processes and materials used in the deposition, patterning, and treatment of substrates and coatings, with representative examples including, but not limited to, applications involving: semiconductor and dielectric materials and devices, silicon-based wafers, flat panel displays (such as TFTs), masks and filters, energy conversion and storage (such as photovoltaic cells, fuel cells, and batteries), solid-state lighting (such as LEDs and OLEDs), magnetic and optical storage, micro-electro-mechanical systems (MEMS) and nano-electro-mechanical systems (NEMS), micro-optic and opto-electro-mechanical systems (NEMS), micro-optic and optoelectronic devices, transparent substrates, architectural and automotive glasses, metallization systems for metal and polymer foils and packaging, and micro- and nano-molding.

[0069] While the foregoing is directed to some embodiments, other and further embodiments may be devised without departing from the scope determined by the claims that follow.

Claims

1. An apparatus for coating a substrate, the apparatus comprising: a vacuum process chamber, the vacuum process chamber comprising: a gas inlet assembly comprising at least one connector for connecting to one or more process gas sources; a sputter assembly comprising a sputter source, wherein the sputter assembly is movable in the vacuum process chamber; and wherein the apparatus comprises: a controller configured for controlling, in dependence of a current position of the sputter assembly or of the sputter source in the vacuum process chamber, at least one of: a flow of a process gas introduced through the gas inlet assembly into the vacuum process chamber, a composition of the process gas introduced through the gas inlet assembly into the vacuum process chamber, a distribution of the process gas introduced through the gas inlet assembly into the vacuum process chamber, and a gas flow pumped out of the vacuum chamber.

2. The apparatus according to claim 1, wherein the sputter source comprises a rotatable target.

3. The apparatus according to any one of claims 1 or 2, comprising a substrate guiding system arranged in the vacuum process chamber, the substrate guiding system being arranged for supporting the substrate during coating and for moving the substrate into and out of the vacuum process chamber, wherein the sputter assembly is movable along the substrate guiding system.

4. The apparatus according to any one of claims 1, 2 or 3, comprising a drive system coupled to the sputter assembly, wherein the drive system is configured for effecting a translational movement of the sputter assembly, and particularly wherein the controller is coupled to the drive system for controlling the translational movement of the sputter assembly.

5. The apparatus according to any one of claims 1, 2, 3 or 4, wherein the gas inlet assembly is movable together with the sputter assembly, particularly wherein the gas inlet assembly and the sputter assembly are mounted on a carriage.

6. The apparatus according to any one of claims 1, 2, 3, 4 or 5, wherein the gas inlet assembly comprises M gas inlets for introducing the process gas into the vacuum process chamber, wherein M is in the range from 1 to 15, and wherein the controller is configured for controlling at least one of the flow of the process gas, the composition of the process gas and the distribution of the process gas flowing through the M gas inlets in dependence of the position of the M gas inlets.

7. The apparatus according to any one of claims 1, 2, 3, 4, 5 or 6, wherein the sputter assembly comprises N further sputter sources, wherein N is in the range from 1 to 10, and wherein the N further sputter sources are of a same type as the sputter source.

8. The apparatus according to any one of claims 1, 2, 3, 4, 5, 6 or 7, further comprising at least one of: a shield arranged at the substrate guiding system, for shielding the substrate or a substrate carrier during coating; a chamber wall of the vacuum process chamber; and one or more vacuum pumps connected to one or more gas outlets of the vacuum process chamber, wherein the controller is configured for varying, depending on whether the sputter assembly or the sputter source faces the substrate or faces the shield or the chamber wall, at least one of: the flow of the process gas, the composition of the process gas, the distribution of the process gas, and the total gas flow pumped out of the vacuum process chamber by the one or more vacuum pumps and the distribution of partial gas flows pumped out of the vacuum process chamber through the one or more gas outlets.

9. The apparatus according to any one of claims 1, 2, 3, 4, 5, 6, 7 or 8, comprising: a power source for applying power to the sputter source, wherein the controller is configured for controlling, in dependence of the current position of the sputter assembly or of the sputter source in the vacuum process chamber, the power applied to the sputter source by the power source.

10. A method for coating a substrate in a vacuum chamber, the method comprising: providing a first process gas environment for a sputter source; sputtering a sputter material from the sputter source in the first process gas environment, wherein the sputter source is located in a first position relative to the substrate; moving the sputter source relative to the vacuum chamber; providing a second process gas environment for the sputter source which is different from the first process gas environment; and sputtering the sputter material from the sputter source in the second process gas environment, wherein the sputter source is located in a second position relative to the substrate.

11. The method according to claim 10, wherein the sputter source is moved continuously while the sputter material is sputtered, and the process gas environment of the sputter source is continuously adapted based on a current position of the sputter source relative to the substrate.

12. The method according to any one of claims 10 or 11, wherein the first process gas environment is determined by a first set of process gas parameters, including at least one of a first process gas composition, a first total inward process gas flow into the first process gas environment, a first distribution of partial inward process gas flows into the first process gas environment, a first total outward gas flow out of the first process gas environment, and a first distribution of partial outward gas flows out of the first process gas environment, and wherein the second process gas environment is determined by a second set of process gas parameters, including at least one of a second process gas composition, a second total inward process gas flow into the second process gas environment, a second distribution of partial inward process gas flows into the second process gas environment, a second total outward gas flow out of the second process gas environment, and a second distribution of partial outward gas flows out of the second process gas environment, wherein at least one of the following holds: the second gas composition is different from the first gas composition; the second total inward process gas flow is different from the first total inward process gas flow; the second distribution of partial inward process gas flows is different from the first distribution of partial inward process gas flows; the second total outward gas flow is different from the first total outward gas flow; and the second distribution of partial outward gas flows is different from the first distribution of partial outward gas flows.

13. The method according to any one of claims 10, 11 or 12, wherein the first process gas environment provided at the first position and the second process gas environment provided at the second position are selected to maintain a working point of sputtering the sputter material constant.

14. The method according to claim 10, 11, 12 or 13, wherein providing the first process gas environment comprises providing the first process gas environment for the sputter source and for N further sputter sources, wherein N is in the range from 1 to 10, and wherein providing the second process gas environment comprises providing the second process gas environment for the sputter source and for the N further sputter sources.

15. The method of any one of claims 10, 11, 12, 13 or 14, wherein the sputter source faces the substrate in the second position and wherein the sputter source faces a component of the vacuum chamber in the first position, in particular a shield or a chamber wall.