WO2020151810A1

WO2020151810A1 - Deposition apparatus and method of operating a deposition apparatus

Info

Publication number: WO2020151810A1
Application number: PCT/EP2019/051463
Authority: WO
Inventors: N S Madhu; Prashant Kasirayagoud BIRADAR; Ralph Lindenberg; Thomas Gebele
Original assignee: Applied Materials, Inc.
Priority date: 2019-01-22
Filing date: 2019-01-22
Publication date: 2020-07-30
Also published as: CN215342496U

Abstract

A deposition apparatus is described. The deposition apparatus includes a vacuum chamber (101), a deposition source (120) including at least one sputter source (121) within the vacuum chamber for coating a substrate on a first side of the deposition source, and a shielding arrangement (130) arranged on a second side of the deposition source. The shielding arrangement includes a plurality of shielding units which partially overlap and define gas flow paths (132) therebetween. The shielding arrangement may include front shielding units (135) and back shielding units (136) which are alternately arranged.

Description

DEPOSITION APPARATUS AND METHOD OF OPERATING A DEPOSITION

APPARATUS

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to layer deposition, particularly to layer deposition by sputtering. Specifically, embodiments relate to a deposition apparatus for depositing layers by sputtering. Embodiments of the present disclosure particularly relate to deposition apparatuses, methods of operating a deposition apparatus, and methods of depositing a layer stack on a substrate.

BACKGROUND

[0002] Several methods are known for depositing a material on a substrate. For instance, substrates can be coated by a physical vapor deposition (PVD) process, such as sputtering, a chemical vapor deposition (CVD) process, or a plasma enhanced chemical vapor deposition (PECVD) process. Typically, the process is performed in a deposition apparatus including a vacuum chamber, where the substrate to be coated is located. A deposition material is provided in the apparatus. The deposition material may, e.g., be sputtered from a sputter target toward the substrate to be coated. A plurality of materials may be used for deposition on a substrate. Among them, many different metals can be used, but also oxides, nitrides or carbides. Typically, a sputter process is suitable for thin film coatings.

[0003] Coated substrates can be used in several applications and in several technical fields. For instance, an application lies in the field of microelectronics, such as generating semiconductor devices. Also, substrates for displays are often coated by a PVD process, wherein large area substrates are processed.

[0004] For processing large area substrates, for example, in the display industry, dynamic deposition processes can be used wherein the substrate is moved past one or more deposition sources during the deposition. Yet, many substrate processing applications utilize a static deposition process. In a static deposition process, the substrate is positioned in a vacuum processing area on a front side of a deposition source. The deposition source may include at least one sputter source or an array of sputter sources which are spaced apart from each other.

[0005] It is challenging to provide most of the sputtered deposition material on the substrate, and to reduce a stray deposition on other components inside the vacuum chamber. In particular, as little deposition material as possible should end up on an inner wall of the vacuum chamber, such that cleaning efforts inside the vacuum chamber due to stray coating can be reduced and material costs can be saved.

[0006] Some deposition apparatuses may be provided with shielding plates inside the vacuum chamber which may be arranged between the deposition source and an inner wall of the vacuum chamber. Cleaning of the shielding plates may be easier and quicker than cleaning of the vacuum chamber, e.g. because the shielding plates can be quickly removed or exchanged. Thus, downtimes of the deposition apparatus can be reduced. However, the shielding arrangement may negatively affect the coating process.

[0007] In light thereof, it would be beneficial to provide an improved deposition apparatus and improved methods of operating a deposition apparatus that enable a good deposition result while reducing stray coating on inner walls of the vacuum chamber.

SUMMARY

[0008] In light of the above, deposition apparatuses and methods of operating a deposition apparatus are provided. Further aspects, advantages, and features of the present disclosure are apparent from the dependent claims, the description, and the accompanying drawings.

[0009] According to one embodiment or aspect, a deposition apparatus is provided. The deposition apparatus includes a vacuum chamber, a deposition source including at least one sputter source within the vacuum chamber for coating a substrate on a first side of the deposition source, and a shielding arrangement arranged on a second side of the deposition source. The shielding arrangement includes a plurality of partially overlapping shielding units which define gas flow paths therebetween. [0010] In some embodiments, a substrate transport track is arranged on the first side of the deposition source, and the shielding arrangement is arranged on the second side of the deposition source opposite the first side, particularly between the deposition source and at least one pump port.

[0011] According to another embodiment or aspect, a deposition apparatus is provided. The deposition apparatus includes a vacuum chamber, a deposition source including an array of four or more sputter sources having magnet assemblies arranged therein, a substrate transport track arranged on a first side of the deposition source, and a shielding arrangement arranged on a second side of the deposition source. The magnet assemblies may be movable between a pre-sputter position for sputter deposition in the direction of the shielding arrangement and a sputter position for sputter deposition in the direction of the substrate transport track. The shielding arrangement includes front shielding units and back shielding units which are alternately arranged.

[0012] In some embodiments, the back shielding units may be arranged to shield a gap between two adjacent front shielding units, respectively, and may partially overlap with said two adjacent front shielding units, respectively.

[0013] According to another embodiment or aspect, a method of operating a deposition apparatus is provided. The method includes providing a deposition source having at least one sputter source in a vacuum chamber, conditioning the at least one sputter source, followed by coating a substrate by sputtering material from the at least one sputter source toward the substrate that is arranged on a first side of the deposition source. The at least one sputter source is conditioned by sputtering material from the at least one sputter source toward a shielding arrangement arranged on a second side of the deposition source, the shielding arrangement including a plurality of shielding units which partially overlap and define gas flow paths therebetween.

[0014] In some embodiments, the vacuum chamber includes a vacuum processing area on a front side of the shielding arrangement and a pumping area on a rear side of the shielding arrangement, the gas flow paths extending from the vacuum processing area to the pumping area through the shielding arrangement. During the conditioning and/or during the coating, gas may be removed from the pumping area with one or more vacuum pumps which are mounted at the pumping area, the gas flowing from the vacuum processing area to the pumping area through the shielding arrangement along the gas flow paths.

[0015] Embodiments are also directed at apparatuses for carrying out the disclosed methods and include apparatus parts for performing each described method aspect. These method aspects may be performed by way of hardware components, a computer programmed by appropriate software, by any combination of the two or in any other manner. Furthermore, embodiments according to the disclosure are also directed at methods for operating the described apparatus. The methods for operating the described apparatus include method aspects for carrying out every function of the apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description, briefly summarized above, may be had by reference to embodiments. The accompanying drawings relate to embodiments of the disclosure and are described in the following:

FIG. 1 shows a schematic sectional view of a deposition apparatus according to embodiments of the present disclosure;

FIG. 2A shows a schematic sectional view of a deposition apparatus according to embodiments of the present disclosure in a pre sputter position;

FIG. 2B shows the deposition apparatus of FIG. 2A in a sputter position;

FIG. 3A shows a schematic sectional view of a deposition apparatus with a shielding arrangement according to embodiments of the present disclosure;

FIG. 3B shows the shielding arrangement of the deposition apparatus of FIG. 3A in a schematic front view; and FIG. 4 shows a flow chart illustrating methods of operating a deposition apparatus according to embodiments of the present disclosure.

DETAILED DESCRIPTION

[0017] Reference will now be made in detail to the various embodiments of the disclosure, one or more examples of which are illustrated in the figures. Within the following description of the drawings, the same reference numbers refer to same components. Generally, only the differences with respect to individual embodiments are described. Each example is provided by way of explanation of the disclosure and is not meant as a limitation. Further, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield yet a further embodiment. It is intended that the description includes such modifications and variations.

[0018] FIG. 1 is a schematic sectional view of a deposition apparatus 100 according to embodiments described herein. The deposition apparatus 100 includes a vacuum chamber 101 and a deposition source 120 provided in a vacuum processing area 102 of the vacuum chamber 101. The deposition source 120 includes a sputter source 121 with at least one sputter target, particularly with an array of sputter targets. The deposition source 120 is configured for coating a substrate 10 that is arranged on a first side of the deposition source 120, the first side corresponding to the front side of the deposition source 120. For example, a substrate transport track 20 for transporting a substrate 10 into the vacuum processing area 102 may be provided in front of the deposition source 120.

[0019] The substrate 10 can be positioned in the vacuum processing area 102 on the first side of the deposition source 120. Thereupon, a material can be deposited on the substrate 10 by sputtering from the at least one sputter source 121. The target material can be thinly deposited on the substrate. The deposition apparatus 100 may be configured for static sputtering. In other words, the substrate can be positioned in front of the deposition source and held essentially stationary during the deposition. Alternatively, the deposition apparatus may be configured for dynamic sputtering, wherein the substrate and the deposition source are moved relative to each other during the deposition. [0020] The deposition apparatus further includes a shielding arrangement 130 that is arranged on a second side of the deposition source 120, particularly opposite the first side, i.e. on a rear side of the deposition source 120. The shielding arrangement 130 may be arranged between the deposition source 120 and an inner wall of the vacuum chamber 101, particularly between the deposition source 120 and at least one pump port 141 of the vacuum chamber 101. The shielding arrangement 130 may be arranged to reduce or prevent stray coating and other undesired deposition on an inner wall 105 of the vacuum chamber 101, particularly on a rear wall of the vacuum chamber, or on other components inside the vacuum chamber that are not meant to be coated.

[0021] A shielding frame 22 may additionally be arranged on the first side of the deposition source 120, i.e. on the front side of the deposition source, in order to reduce a stray coating inside the vacuum chamber adjacent to the edges of the substrate during the deposition on the substrate.

[0022] According to embodiments described herein, the shielding arrangement 130 is provided on the second side of the deposition source 120 different from the first side where the substrate 10 is to be arranged. Providing the shielding arrangement 130 on the second side of the deposition source may be beneficial in the event that the sputter direction of the at least one sputter source 121 can be changed. In particular, during a pre- sputtering process, i.e. before the start of the actual deposition on the substrate 10, material may be sputtered from the at least one sputter source 121 toward the shielding arrangement 130. Contaminants and other materials such as water or dirt that may have built up on the target surface of the at least one sputter source 121 during idle times of the deposition apparatus can be removed from the at least one sputter source in the direction of the shielding arrangement 130. Accordingly, pre sputtering in the direction of the shielding arrangement 130 may improve the quality of the layer deposited on the substrate, because contaminants can be released from the surface of the at least one sputter source during the pre- sputtering process, i.e. before the actual sputtering starts.

[0023] By arranging the shielding arrangement 130 on the second side of the deposition source 120 different from the first side, a deposition of material on an inner wall 105 of the vacuum chamber or a deposition on other components inside the vacuum chamber that are not meant to be coated can be reduced or prevented during the pre-sputter process, the pre-sputter process taking place on the second side of the deposition source.

[0024] According to embodiments described herein, the deposition source 120 can be set to a pre-sputter position in which the at least one sputter source is sputtered on the second side, such that target material is directed in the direction of the shielding arrangement 130, and can be set to a sputter position in which the at least one sputter source is sputtered on the first side, such that target material is directed in the direction where the substrate is to be arranged. A deposition on the inner wall 105 of the vacuum chamber behind the shielding arrangement 130 can be reduced or prevented in the pre-sputter position, since the shielding arrangement 130 is arranged between the deposition source and the inner wall 105 of the vacuum chamber on the second side of the deposition source.

[0025] In particular, the shielding arrangement 130 may be shaped and arranged such that, when the deposition source is set in the pre-sputter position, essentially all straight paths from the at least one sputter source 121 to the inner wall 105 of the vacuum chamber on the second side of the deposition source are blocked by the shielding arrangement. For example, the shielding arrangement 130 may include one or more shielding plates that prevent a deposition of target material on components that are arranged behind the one or more shielding plates, as viewed from the deposition source.

[0026] The shielding arrangement may be releasably fixed inside the vacuum chamber, e.g. via screws, such that the shielding arrangement can be removed and/or exchanged for cleaning.

[0027] A shielding arrangement may negatively affect the fluid conductance between an area on a front side of the shielding arrangement, also referred to herein as “vacuum processing area 102”, and an area on a rear side of the shielding arrangement, also referred to herein as“pumping area 103”. In particular, a shielding arrangement may constitute an obstacle in a pumping path along which process gases, other gases and/or gaseous contamination particles, e.g. water, are removed from the vacuum chamber 101 by one or more vacuum pumps, e.g. when at least one pump port 141 is arranged in the pumping area 103 on the rear side of the shielding arrangement. [0028] According to embodiments described herein, the shielding arrangement 130 comprises shielding units 131, namely a plurality of shielding units, e.g., seven or more shielding units, which partially overlap and define gas flow paths 132 therebetween. By segmenting the shielding arrangement 130 in a plurality of spaced- apart shielding units defining gas flow paths 132 therebetween, a better pumping efficiency can be enabled and the fluid conductance at the vacuum processing area can be increased. In particular, fluid can be pumped more efficiently from the vacuum processing area 102 in front of the shielding arrangement 130 to the pumping area 103 on the rear side of the shielding arrangement, where the at least one pump port 141 is arranged.

[0029] In particular, the plurality of shielding units 131 may be arranged spaced- apart from each other in an array, such that two neighboring shielding units define a gas flow path therebetween, respectively. Accordingly, if a total of seven or more shielding units 131 are provided, a total of six or more gas flow paths 132 are provided between said shielding units, allowing a good pumping efficiency for pumping process gases and/or gaseous contaminants through the shielding arrangement 130, e.g. by a vacuum pump mounted at the pumping area 103. Each gas flow path may extend from the vacuum processing area 102 to the pumping area 103 through the shielding arrangement 130. Thus, gases can be quickly and reliably removed from the vacuum processing area 102 by one or more vacuum pumps arranged at the pumping area 103.

[0030] Since the shielding units 131 are provided in an overlapping way, a propagation of deposition material through gaps between the shielding units 131 along straight deposition paths during the pre-sputter process can be reduced or prevented. Accordingly, stray coating of the inner wall 105 of the vacuum chamber 101 on the rear side of the shielding arrangement 130 can be reduced or prevented. As is schematically depicted in FIG. 1, two adjacent shielding units may overlap in an overlap region extending over a distance of X in a horizontal direction, particularly wherein X is 4 cm or more, particularly 7 cm or more. Two adjacent shielding units of the array of shielding units 131 may overlap over a distance of X or more, respectively.

[0031] “Partially overlapping shielding units” as used herein may be understood to mean that two adjacent shielding units horizontally (or vertically) overlap, respectively. In other words, there is an overlap region in which a line perpendicularly extending with respect to the substrate plane intersects both of the two adjacent shielding units. Further, the two adjacent shielding units are arranged spaced apart from each other, respectively, to define a gas flow path therebetween. In the embodiment depicted in FIG. 1, the overlap region extends over a distance of X in a horizontal direction, the horizontal direction corresponding to a substrate transport direction, particularly wherein X is 4 cm or more, particularly 7 cm or more. Thus, even deposition material propagating along a tilted deposition path from the at least one sputter source 121 cannot penetrate through the shielding arrangement 130 due to the overlap between neighboring shielding units, as is schematically illustrated by reference numeral 106 in FIG. 1. A“tilted” deposition path may be understood as a deposition path having non perpendicular angle with respect to the substrate surface, e.g. an angle between 5° and 45°.

[0032] In some embodiments, which may be combined with other embodiments described herein, the shielding arrangement 130 includes seven or more shielding units 131 defining six or more gas flow paths 132 therebetween, as is schematically depicted in FIG. 1. In some embodiments, the shielding arrangement includes eleven or more, particularly fifteen or more shielding units, which may define ten or more, particularly sixteen or more gas flow paths therebetween.

[0033] In implementations, the shielding arrangement 130 may provide a permeable shielding wall extending essentially parallel to the substrate plane, the permeable shielding wall including a plurality of spaced apart shielding plates defining gas flow paths therebetween and being arranged on the rear side of the deposition source 120, particularly between the deposition source 120 and a rear wall of the vacuum chamber where at least one pump port may be provided. In particular, the shielding wall may include a plurality of spaced apart pre- sputter plates that reduce the stray coating on the rear wall of the vacuum chamber during the pre-sputter process. During the pre-sputter process, the direction of sputter deposition from the deposition source may be reversed.

[0034] Accordingly, the gas flow at the vacuum processing area 102 on the front side of the shielding arrangement 130 toward the rear side of the shielding arrangement is not substantially restricted by the shielding arrangement, and problems due to pressure drop from the vacuum processing area 102 to the pumping area 103 can be reduced. The tact time and the process quality can be increased. In particular, the shielding arrangement 130 may provide a plurality of labyrinth ducts having a duct size suitable for increasing the fluid conductance through the shielding arrangement.

[0035] In some embodiments, which can be combined with other embodiments described herein, the shielding arrangement 130 includes front shielding units 135 and back shielding units 136. The front shielding units 135 may be arranged closer to the deposition source 120 than the back shielding units 136. For example, the front shielding units 135 may define a first shielding plane and the back shielding units 136 may define a second shielding plane which is farther from the deposition source 120 than the first shielding plane. Both the first shielding plane and the second shielding plane may be essentially parallel to the substrate plane in which the substrate is to be arranged for coating.

[0036] In some implementations, the front shielding units 135 and the back shielding units 136 are alternately arranged. In particular, at least one back shielding unit may be arranged to shield a gap between two adjacent front shielding units and may partially overlap with said two adjacent front shielding units. In particular, the front shielding units 135 may be arranged next to each other and spaced apart from each other in an essentially linear array (line array), such that gaps are defined between two adjacent front shielding units, respectively. These gaps may be shielded by a respective back shielding unit, wherein the back shielding units 136 may be arranged in a linear array (line array)“behind” the front shielding units 135, e.g. closer to a rear wall of the vacuum chamber 101 than the front shielding units 135. Accordingly, straight deposition paths through the gaps between two adjacent front shielding units are blocked by a respective back shielding units, respectively. A stray deposition on the inner wall 105 of the vacuum chamber 101 behind the shielding arrangement 130 can be reduced or prevented.

[0037] Due to the overlaps between the front shielding units and the back shielding units, a stray deposition through the shielding arrangement during the pre-sputter process, in which the direction of sputter deposition is inversed, can be reduced or avoided.

[0038] In some embodiments, which may be combined with other embodiments described herein, the deposition source 120 includes an array of four or more sputter sources having magnet assemblies arranged therein. The magnet assemblies may be movable between a pre sputter position for a sputter deposition in the direction of the shielding arrangement 130 and a sputter position for a sputter deposition in the direction of the substrate 10 that is to be coated. During the pre-sputter process, the magnet assemblies may be arranged in the pre sputter position, such that the material sputtered from the array of sputter sources propagates toward the pumping area and is shielded by the shielding arrangement 130. During the actual sputtering, the magnet assemblies may be arranged in the sputter position, such that the material sputtered from the array of sputter sources propagates toward the substrate on the first side of the deposition source and is deposited on the substrate.

[0039] Both during the pre-sputter process and during the actual sputtering, an efficient pumping of process gas and/or other gases (including gaseous contaminants such as water molecules) through the shielding arrangement 130 is ensured due to the plurality of gas flow paths 132 extending through the shielding arrangement.

[0040] In some embodiments, which may be combined with other embodiments described herein, the at least one sputter source 121 is rotatable around an axis. A more uniform consumption of the target material of the at least one sputter source 121 can be ensured when the at least one sputter source 121 rotates around the axis during the sputtering, particularly at an essentially constant angular speed.

[0041] In some embodiments, the deposition source 120 includes an array of sputter sources, each sputter source being rotatable. The array of sputter sources may be arranged in an essentially linear setup, as is schematically depicted in FIG. 1. A magnet assembly may be arranged inside each of the sputter sources of the array of sputter sources.

[0042] According to embodiments described herein, the gas flow paths 132 extend from the vacuum processing area 102 on the front side of the shielding arrangement 130 to the pumping area 103 on the rear side of the shielding arrangement 130. At least one pump port 141 for mounting a vacuum pump to the vacuum chamber 101 may be arranged on the rear side of the shielding arrangement 130. Accordingly, the at least one pump port 141 is provided at the pumping area 103, and process gases and other gases which may be present in the vacuum processing area 102 flow through the shielding arrangement 130 into the pumping area 103 for being removed from the vacuum chamber 101 through the at least one pump port 141. In some embodiments, the deposition apparatus may further include at least one gas inlet for introducing a process gas into the vacuum processing area 102.

[0043] FIG. 2A shows a schematic sectional view of a deposition apparatus 200 according to embodiments of the present disclosure in the pre-sputter position. FIG. 2B shows the deposition apparatus 200 of FIG. 2A in the sputter position. In the pre-sputter position, the at least one sputter source 121 is sputtered in order to free the at least one sputter source from contaminants such as water, the pre- sputtering taking place on the second side of the deposition source. Material from the sputter source is deposited on the shielding arrangement 130. In the sputter position, the at least one sputter source 121 is sputtered in order to deposit the target material of the at least one sputter source 121 on a substrate 10 that is arranged on the first side of the deposition source 120. The deposition apparatus 200 is similar to the deposition apparatus 100 depicted in FIG. 1, such that reference can be made to the above explanations, which are not repeated here.

[0044] The deposition apparatus 200 includes a vacuum chamber 101, a deposition source 120 within the vacuum chamber, a substrate transport track 20 on a first side of the deposition source 120 and a shielding arrangement 130 on a second side of the deposition source 120, particularly opposite the first side. The shielding arrangement 130 may be arranged on a rear side of the deposition source 120, namely between the deposition source 120 and at least one pump port 141 for mounting a vacuum pump.

[0045] As is schematically depicted in FIG. 2A, the deposition source 120 includes at least one sputter source 121, particularly an array of four, eight, twelve, sixteen or more sputter sources, which may be arranged spaced apart from each other in an essentially linear setup (i.e., a line array of sputter targets). An“essentially linear setup” as used herein encompasses a slightly bent arrangement of the sputter sources, in which outer sputter sources are arranged closer to the substrate transport track 20 as compared to inner sputter sources of the array, as is schematically depicted in FIG. 2A.

[0046] The array of sputter sources may have magnet assemblies arranged therein. In particular, each sputter source of the array of sputter sources may be a rotatable sputter source having a magnet assembly 122 arranged therein. The magnet assemblies may be movable between a pre-sputter position for sputter deposition in the direction of the shielding arrangement 130 and a sputter position for sputter deposition in the direction of the substrate transport track 20. In the pre-sputter position, the magnet assemblies may be arranged to confine respective plasmas on the second side of the sputter sources, such that material is sputtered from the array of sputter sources toward the shielding arrangement. In the sputter position, the magnet assemblies may be arranged to confine respective plasmas on the first side of the sputter sources, such that sputter deposition from the array of sputter sources takes place toward the substrate transport track 20 where the substrate is to be arranged.

[0047] The shielding arrangement 130 may separate a vacuum processing area 102 on a front side of the shielding arrangement 130 from a pumping area 103 on a rear side of the shielding arrangement, while allowing a gas flow between said two areas. The shielding arrangement includes shielding units 131 which partially overlap and define gas flow paths 132 therebetween. The gas flow paths 132 may extend through the shielding arrangement 130 from the vacuum processing area 102 to the pumping area 103. Due to the overlap of adjacent shielding units, a stray deposition of surfaces inside the pumping area 103 can be reduced or prevented. Reference is made to the above explanations, which are not repeated here.

[0048] In some embodiments, the number of gas flow paths 132 between adjacent shielding units corresponds to the number of sputter sources of the array of sputter sources or is larger than the number of sputter sources. For example, if the array of sputter sources includes ten or more sputter sources, the number of gas flow paths 132 may be at least ten. The gas flow paths may be provided spaced apart from each other in a horizontal direction, which may correspond to the substrate transport direction or to the direction in which the line array of sputter sources extends. Accordingly, an efficient pumping through the shielding arrangement along the whole extension of the deposition source 120 can be ensured.

[0049] As is schematically depicted in FIG. 2A, the shielding units 131 may include front shielding units 135 and back shielding units 136, the front shielding units 135 being arranged closer to the deposition source 120 than the rear shielding units. The front shielding units 135 and the back shielding units 136 may be alternately arranged, a respective back shielding units being arranged to shield a gap between two adjacent front shielding units, and particularly partially overlapping with said two adjacent front shielding units.

[0050] The shielding units 131 may be configured as shielding plates, particularly as bent shielding plates, more particularly as C-shaped or U-shaped shielding plates, respectively. As is schematically depicted in FIG. 2A, the front shielding units 135 may be U-shaped shielding plates, and/or the back shielding units 136 may be U-shaped shielding plates. The gas flow paths 132 are provided between a respective front shielding unit and a respective adjacent rear shielding unit. In particular, two adjacent front shielding units may define a gap therebetween, respectively, which may be shielded by a respective back shielding unit that may be arranged behind the front shielding units.

[0051] The risk of stray coating of components inside the pumping area 103 can be further reduced if the front shielding units 135 and the back shielding units 136 are configured as inversely arranged U-shaped shielding plates defining labyrinth ducts therebetween. The main flow direction of gas propagating through one of the labyrinth ducts may change at least once. For example, as is schematically depicted in FIG. 2A, at least one gas flow path or all the gas flow paths may extend from the vacuum processing area 102 through a gap between adjacent front shielding units toward one of the back shielding units, whereupon the main flow direction of the gas changes sideways and partially backwards, past and around the respective back shielding unit. When the front shielding units 135 and the back shielding units 136 are configured as inversely arranged U-shaped shielding plates, suitable labyrinth ducts can be provided when the side legs of the inversely arranged U-shaped shielding plates are directed toward each other and/or partially engage with each other. The risk of stray coating during the pre-sputter process through the shielding arrangement can be further reduced.

[0052] The at least one sputter source 121 of the deposition source 120 may have the magnet assembly 122 arranged therein that is movable to the pre-sputter position depicted in FIG. 2A. In the pre-sputter position depicted in FIG. 2A, the at least one sputter source 121 can be sputtered to remove contaminants such as water from the at least one sputter source in the direction of the shielding arrangement 130 and through the shielding arrangement along the gas flow paths. Gaseous contaminants, such as water, may propagate through one of the gas flow paths toward the at least one pump port 141 and may be removed from the vacuum chamber 101. The vacuum conditions and the coating quality can be improved. Target material sputtered during the pre-sputter process from the at least one sputter source 121 propagates to and is blocked by the partially overlapping shielding units 131 of the shielding arrangement 130. The shielding units 131 can be removed from the vacuum chamber for cleaning at predetermined cleaning intervals, if appropriate.

[0053] The magnet assembly 122 may be moved to the sputter position depicted in FIG. 2B, in which the magnet assembly 122 is arranged to confine a plasma on the first side of the at least one sputter source 121. In the sputter position depicted in FIG. 2B, the at least one sputter source 121 may be sputtered to provide target material on the substrate 10 that is arranged in front of the deposition source 120 on the substrate transport track 20. A thin and uniform layer free of contaminants can be deposited on the substrate, as contaminants, which may have initially been present within the vacuum chamber, can be removed during the pre sputter process. Gases can be efficiently pumped from the vacuum processing area 102 of the vacuum chamber 101 via the at least one pump port 141, since the shielding arrangement has the plurality of gas flow paths extending therethrough.

[0054] FIGS. 2A and 2B show the deposition apparatus 200 in a sectional plane that horizontally intersects the deposition apparatus 200. The at least one sputter source 121 may be an essentially cylindrical sputter source extending in a vertical direction, i.e. perpendicular to the paper plane. The substrate plane may be an essentially vertical plane, and the substrate transport direction may be an essentially horizontal direction.

[0055] In sectional planes horizontally intersecting the shielding arrangement 130, a clear width of the gas flow paths 132 between the vacuum processing area 102 and the pumping area 103 may be 25 mm or more. In other words, the dimension of a gas flow path perpendicular to the gas main flow direction may never be smaller than 25 mm. A clear width of the gas flow paths of 25 mm or more is beneficial because strong constrictions of the gas flow paths would considerably affect the overall fluid conductance from the vacuum processing area 102 to the pumping area 103 along the gas flow paths.

[0056] For example, as is schematically depicted in FIG. 2A, a distance A between two adjacent front shielding units defining the entrance of one labyrinth duct may be 25 mm or more, particularly 50 mm or more. Alternatively or additionally, the smallest distance between a front shielding unit and an adjacent back shielding unit may be 25 mm or more, particularly 30 mm or more. For example, the distance B between a front shielding unit and a back shielding unit at a first constriction position may be about 25 mm or more, and a distance C between the front shielding unit and the back shielding unit at a second constriction position may be about 35 mm or more. The gas flow paths 132 may be shaped similarly and/or may be shaped as mirror images of other gas flow paths, having essentially same clear widths. Accordingly, the fluid conductances provided by the gas flow paths may be similar, such that the gas can be efficiently pumped through the shielding arrangement along the whole lateral extension of the shielding arrangement.

[0057] As is further depicted in FIG. 2A and FIG. 2B, the vacuum chamber 101 may include at least one pump port 141, particularly three or more pump ports, arranged at the rear side of the shielding arrangement 130 for removing gases from the vacuum chamber by pumping from the pumping area 103. At least one of a cryochiller and a turbomolecular pump may be mounted at the at least one pump port. In embodiments, at least one cryochiller and at least one turbomolecular pump are provided at three or more pump ports of the vacuum chamber, particularly at six or more pump ports of the vacuum chamber. The six or more pump ports may be provided at the pumping area 103 of the vacuum chamber, e.g. at a back wall of the vacuum chamber.

[0058] As is schematically depicted in FIG. 2A, at least one gas inlet 160 for introducing a process gas into the vacuum processing area 102 may be provided, wherein the at least one gas inlet 160 may extend through one of the shielding units 131, particularly through one of the front shielding units 135. In particular, a plurality of gas inlets may be provided, each gas inlet extending through one of the front shielding units 135. Accordingly, the process gas can be directly introduced into the vacuum processing area 102 and be directed toward the array of sputter sources.

[0059] FIG. 3A is a schematic sectional view of a deposition apparatus 300 including a shielding arrangement 130 according to embodiments of the present disclosure. FIG. 3B shows the shielding arrangement of the deposition apparatus 300 in a front view. The deposition apparatus 300 may be similar to the deposition apparatus 100 depicted in FIG. 1 and to the deposition apparatus 200 depicted in FIG. 2A, such that reference can be made to the above explanations, which are not repeated here.

[0060] The deposition apparatus 300 includes a vacuum chamber 101, a deposition source 120 with an array of sputter sources inside the vacuum chamber 101, and a shielding arrangement 130 arranged on the second side of the deposition source 120, i.e. on the rear side opposite the side where the substrate is to be arranged. The array of sputter sources may include a total of twelve or more sputter sources, particularly 16 sputter sources, each sputter source including a rotatable target and a magnet assembly arranged in the rotatable target.

[0061] The shielding arrangement 130 is arranged between the vacuum processing area 102 where the deposition source is arranged and the pumping area 103 where a plurality of pump ports is arranged, and the shielding arrangement 130 provides a plurality of gas flow paths from the vacuum processing area to the pumping area. The gas flow paths may be labyrinth ducts extending between adjacent shielding units in a curved manner, respectively. In other words, the shielding units may be arranged in an overlapping way such that there is no straight flow path from the vacuum processing area 102 to the pumping area 103, and the gas flows along the gas flow paths along a curved path in which a gas main flow direction is changed at least once.

[0062] The shielding arrangement 130 may include eleven or more, particularly fifteen or more shielding units which are spaced apart from each other, two adjacent shielding units overlapping with each other to define a respective gas flow path therebetween. Ten or more gas flow paths, particularly fourteen or more gas flow paths, may be provided, allowing a gas flow in a horizontal sectional plane into the pumping area, as is depicted in FIG. 3A. In particular, the shielding units may include front shielding units 135, particularly U-shaped shielding plates with side legs directed away from the deposition source 120, and back shielding units 136, particularly U-shaped shielding plates with side legs directed toward the deposition source 120. The front shielding units 135 are arranged closer to the deposition source than the back shielding units. In some embodiments, all front shielding plates are correspondingly shaped, and all back shielding plates are correspondingly shaped. This allows an easy manufacture and exchange of the shielding units. [0063] The shielding units may be shielding plates which extend in an essentially vertical direction, respectively. The height of the shielding plates may be 1 m or more, particularly 2 m or more, more particularly 3 m or more.

[0064] FIG. 3B shows the shielding arrangement 130 in a front view, i.e. as viewed from the deposition source 120. In FIG. 3B, the front surfaces of the front shielding units 135 and the gaps between adjacent front shielding units 135 that define the entrances of the gas flow paths 132 are clearly visible. Further, it is shown that the gaps between adjacent front shielding units are completely shielded by the back shielding units 136. Accordingly, a vertical shielding wall is formed by the overlapping shielding units that cannot be penetrated along straight deposition paths. Hence, the shielding arrangement provides a pre-sputter plate that is closed for sputter deposition and open for gas flow.

[0065] The dimension of the shielding arrangement 130 in the vertical direction V may be 2 m or more, particularly 3 m or more. The dimension of the shielding arrangement in the horizontal direction H may be 2 m or more, particularly 3 m or more. The front shielding units 135 may have a dimension in the horizontal direction between 20 cm and 50 cm, respectively, and the gaps between adjacent front shielding units 135 may have a dimension in the horizontal direction H between 5 cm and 10 cm, respectively. A plurality of front shielding units 135 may be arranged next to each other in the horizontal direction in a line array, the plurality of front shielding units 135 extending essentially parallel to each other in the vertical direction V.

[0066] In some embodiments, at least one shielding unit may include a plurality of shielding sections, which may be arranged one after the other, particularly in the vertical direction V. Adjacent shielding sections of the at least one shielding unit may overlap in overlap regions 171 to define a gas flow path therebetween. In particular, as is schematically depicted in FIG. 3B, the front shielding units 135 may include a plurality of front shielding sections 172, respectively, which are arranged one after the other in the vertical direction V. The front shielding sections 172 may be U-shaped shielding plates, respectively. Each front shielding unit may include three, four or more front shielding sections in some embodiments. Adjacent front shielding sections of one front shielding unit may overlap and be spaced apart from each other in an overlap region to define a gas flow path therebetween. The overlap regions 171 are shaded in FIG. 3B. Alternatively or additionally, the back shielding units 136 may include a plurality of back shielding sections 173, respectively, which are arranged one after the other in the vertical direction V. Each back shielding unit may include three, four or more back shielding sections in some embodiments. Adjacent back shielding sections of one back shielding unit may overlap and be spaced apart from each other in an overlap region to define a gas flow path therebetween.

[0067] The fluid conductance from the vacuum processing area 102 to the pumping area 103 can be further increased if the shielding arrangement 130 includes a two-dimensional array of overlapping shielding plates. As is depicted in FIG. 3B, in the horizontal direction H, the shielding units 131 may be arranged one after the other in an overlapping manner to define gas flow paths therebetween, and, in the vertical direction V, the shielding sections of the shielding units 131 may be arranged one after the other in an overlapping manner to define gas flow paths therebetween. The removal of gases from the vacuum chamber 101 by pumping at the pumping area 103 can be facilitated due to the increased fluid conductance through the shielding arrangement.

[0068] In some embodiments, the vacuum chamber includes at least one pump port 141, particularly wherein a cryochiller 142 and/or a turbomolecular pump 143 are mounted at the at least one pump port 141. In particular, at least three pump ports may be provided at the pumping area 103, and at least one cryochiller and at least one turbomolecular pump may be mounted at the at least three pump ports. The at least one turbomolecular pump is particularly beneficial for maintaining a low background pressure during the sputter deposition by removing the processing gas from the vacuum chamber. A cryo surface of the cryochiller may act as a water pump by condensing water vapor. Thus, the water pumping speed can be increased, which leads to a reduction in water vapor partial pressure in the vacuum chamber. A lower water vapor partial pressure during sputtering may be beneficial for the sputter coating process. In particular, since the conductance of the shielding arrangement is increased according to embodiments described herein, water condensation on the cryo surface that is provided in the pumping area 103 is increased. As a result, the water pumping speed can be increased. In some embodiments, which may be combined with other embodiments described herein, at least one surface in the pumping area 103 may be coolable, and may particularly be configured as a cryo surface for condensing water vapor. More particularly, one or more cryochillers may be provided for condensing water vapor in the pumping area 103.

[0069] According to embodiments described herein, a better pumping efficiency is enabled by increasing the fluid conductance through the shielding arrangement. A plurality of labyrinth ducts having a suitable duct size is provided between the shielding units which act as pre-sputter places for providing a better cross conductance. The fluid conductance toward the pumping area can be increased by more than 200% as compared to other designs which use one simple pre-sputter plate. Accordingly, the pumping efficiency can be increased by more than 20% and costs can be reduced since the maintenance time is positively influenced.

[0070] In some embodiments, the shielding units may be bent sheet metal plates. In some embodiments, the shielding units may not be embossed. In some embodiments, the shielding units may be arc sprayed surface treated.

[0071] FIG. 4 shows a flow chart illustrating a method of operating a deposition apparatus according to embodiments of the present disclosure. The deposition apparatus may correspond to any of the deposition apparatuses described herein.

[0072] In box 410, a deposition source comprising at least one sputter source is provided in a vacuum chamber. The sputter source may include an essentially cylindrical sputter target, e.g. comprised of a metal. In some embodiments, the deposition source may include an array of sputter sources which may be rotatable. A movable magnet assembly may be provided in the at least one sputter source, particularly in each sputter source of the array of sputter sources.

[0073] In box 420, the at least one sputter source is conditioned by sputtering material from the at least one sputter source toward a shielding arrangement 130 arranged on a second side of the deposition source in a pre-sputter process, i.e. before starting with the sputter deposition on the substrate. The shielding arrangement includes a plurality of shielding units, e.g. seven or more spaced-apart shielding units, which partially overlap and define gas flow paths therebetween. Contaminants such as water may be removed from the at least one sputter source. At least some gaseous contaminants may flow from the vacuum processing area 102 on the front side of the shielding arrangement to the pumping area 103 on a rear side of the shielding arrangement along the gas flow paths. The contaminants may be removed from the vacuum chamber by pumping from at least one pump port provided at the pumping area.

[0074] After the conditioning, the at least one sputter source may be clean and/or the background gas conditions inside the vacuum chamber may have improved, and sputter deposition on the substrate can start. In particular, contaminants may have been removed from the inner volume of the vacuum chamber during the conditioning, and good pressure conditions and a low water content in the vacuum processing area can be ensured.

[0075] Thereafter, in box 430, the substrate can be coated by sputtering material from the at least one sputter source toward the substrate that is arranged on the first side of the deposition source opposite the second side.

[0076] In some embodiments, which may be combined with other embodiments described herein, the vacuum chamber includes a vacuum processing area on a front side of the shielding arrangement and a pumping area on a rear side of the shielding arrangement. The method may further include, during conditioning in box 420 and/or during coating in box 430, removing gas from the pumping area 103 with one or more vacuum pumps, the gas flowing from the vacuum processing area to the pumping area through the shielding arrangement along the gas flow paths.

In some implementations, the gas flow paths are labyrinth ducts in which a gas main flow direction is reversed at least once, and/or which have a clear width of 25 mm or more along the extension of the gas flow paths.

[0077] In some embodiments, the deposition apparatus includes a vacuum chamber 101 sized to accommodate a large area substrate of generation GEN 2 or higher, such as GEN 5 or higher. The large area substrate may be rectangular. A substrate transport track may be provided, along which the substrate can be transported. The substrates may be carried by substrate carriers during the transport and/or during the processing.

[0078] According to embodiments, which can be combined with other embodiments described herein, a sputter source may include a sputter target, particularly a rotatable target. A rotatable target may be rotatable around an axis. A rotatable target may have a curved surface, for example a cylindrical surface. The rotatable target may be rotated around the rotation axis being the axis of a cylinder or a tube during sputtering. This may increase material utilization.

[0079] A sputter source may include a magnet assembly. A magnet assembly may be arranged inside the rotatable target of the sputter source. The magnet assembly may be movable inside the rotatable target, such that the sputtered target material can, depending on the position of the magnet assembly, be directed toward the substrate and/or directed toward the shielding arrangement 130, which may act as a pre-sputter plate. The magnet assembly can generate a magnetic field. The magnetic field may cause one or more plasma regions to be formed near the magnetic field during the pre-sputter process and/or during the actual sputtering. The position of the magnet assembly within the rotatable sputter target affects the direction in which target material is sputtered away from the cathode assembly.

[0080] During the sputter deposition on the substrate, the magnet assemblies (or “magnetrons”) may be moved in a wobbling manner or may be set to various sputtering positions. A magnet assembly that moves during the sputter deposition on the substrate may be beneficial to improve the layer uniformity, particularly for large area substrates, such as substrates for display manufacturing.

[0081] The term“substrate” as used herein embraces both inflexible substrates, e.g., a glass substrate, a wafer, slices of transparent crystal such as sapphire or the like, or a glass plate, and flexible substrates, such as a web or a foil. According to some embodiments, which can be combined with other embodiments described herein, embodiments described herein can be utilized for Display PVD, i.e. sputter deposition on large area substrates for the display market. The deposition apparatus may be configured for the deposition of layers on at least one of semiconductor, metal, and glass substrates. In particular, the deposition apparatus may be configured for the manufacture of at least one of semiconductor devices and display devices.

[0082] According to some embodiments, large area substrates or respective carriers, wherein the carriers may carry one substrate or a plurality of substrates, may have a size of at least 0.67 m². The size may be from about 0.67m² (0.73 m x 0.92 m - Gen 4.5) to about 8 m², more specifically from about 2 m² to about 9 m², or even up to 12 m². The substrates or carriers, for which the structures, apparatuses, such as cathode assemblies, and methods according to embodiments described herein are provided, can be large area substrates as described herein. For instance, a large area substrate or carrier can be GEN 4.5, which corresponds to about 0.67 m² substrates (0.73 m x 0.92 m), GEN 5, which corresponds to about 1.4 m² substrates (1.1 m x 1.3 m), GEN 7.5, which corresponds to about 4.29 m² substrates (1.95 m x 2.2 m), GEN 8.5, which corresponds to about 5.7m² substrates (2.2 m x 2.5 m), or even GEN 10, which corresponds to about 8.7 m² substrates (2.94 m x 3.37 m). Even larger generations such as GEN 11 and GEN 12 and corresponding substrates can similarly be implemented.

[0083] According to some embodiments of the present disclosure, a deposition system is provided. The deposition system includes a first deposition apparatus according to embodiments described herein and at least one further deposition apparatus according to embodiments described herein. The first deposition apparatus may be configured to deposit a first material and the at least one further deposition apparatus is configured to deposit a second material different from the first material on a substrate. One or more deposition apparatuses in a deposition system, particularly a vacuum deposition system, can be provided according to embodiments described herein. [0084] While the foregoing is directed to embodiments of the disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

1. A deposition apparatus, comprising: a vacuum chamber (101); a deposition source (120) comprising at least one sputter source (121) within the vacuum chamber for coating a substrate (10) on a first side of the deposition source (120); and a shielding arrangement (130) arranged on a second side of the deposition source (120), the shielding arrangement (130) comprising shielding units (131) which partially overlap and define gas flow paths (132) therebetween.

2. The deposition apparatus of claim 1, wherein the shielding arrangement (130) comprises seven or more shielding units (131), particularly fifteen or more shielding units, defining six or more gas flow paths therebetween, particularly fourteen or more gas flow paths therebetween.

3. The deposition apparatus of claim 1 or 2, wherein the shielding units (131) are shielding plates, particularly bent shielding plates, more particularly C-shaped or U-shaped shielding plates.

4. The deposition apparatus of any of claims 1 to 3, wherein the shielding arrangement (130) comprises front shielding units (135) and back shielding units (136) which are alternately arranged, wherein two adjacent front shielding units provide a gap therebetween, respectively, which is shielded by a respective back shielding unit.

5. The deposition apparatus of claim 4, wherein the front shielding units (135) and the back shielding units (136) are configured as inversely arranged U-shaped shielding plates defining labyrinth ducts therebetween.

6. The deposition apparatus of claim 4 or 5, wherein the front shielding units (135) comprise a plurality of front shielding sections (172), respectively, which are arranged one after the other in an essentially vertical direction (V), and/or wherein the back shielding units (136) comprise a plurality of back shielding sections (173), respectively, which are arranged one after the other in the essentially vertical direction (V).

7. The deposition apparatus of any of claims 1 to 6, wherein the at least one sputter source (121) is rotatable around an axis.

8. The deposition apparatus of any of claims 1 to 7, wherein the at least one sputter source (121) has a magnet assembly (122) arranged therein that is movable between a pre sputter position and a sputter position.

9. The deposition apparatus of any of claims 1 to 8, wherein the deposition source (120) comprises an array of four, eight, twelve, sixteen or more sputter sources (121) arranged in an essentially linear setup.

10. The deposition apparatus of any of claims 1 to 9, wherein the gas flow paths (132) extend from a vacuum processing area (102) on a front side of the shielding arrangement (130) to a pumping area (103) on a rear side of the shielding arrangement, the deposition apparatus further comprising at least one gas inlet (160) for introducing a process gas into the vacuum processing area (102), particularly wherein the at least one gas inlet (160) extends through one of the shielding units (131).

11. The deposition apparatus of any of claims 1 to 10, wherein, in sectional planes horizontally intersecting the shielding arrangement (130), a clear width of the gas flow paths between the vacuum processing area (102) and the pumping area (103) is 25 mm or more.

12. The deposition apparatus of any of claims 1 to 11, wherein the vacuum chamber (101) comprises at least one pump port (141) arranged at a rear side of the shielding arrangement (130).

13. A deposition apparatus (100), comprising: a vacuum chamber (101); a deposition source (120) comprising an array of sputter sources having magnet assemblies arranged therein; a substrate transport track (20) arranged on a first side of the deposition source (120); and a shielding arrangement (130) arranged on a second side of the deposition source (120), the shielding arrangement (130) comprising front shielding units (135) and back shielding units (136) which are alternately arranged, the magnet assemblies being movable between a pre-sputter position for sputter deposition in the direction of the shielding arrangement (130) and a sputter position for sputter deposition in the direction of the substrate transport track (20).

14. A method of operating a deposition apparatus, comprising: providing a deposition source (120) comprising at least one sputter source (121) in a vacuum chamber (101); conditioning the at least one sputter source (121) by sputtering material from the at least one sputter source toward a shielding arrangement (130) arranged on a second side of the deposition source (120), wherein the shielding arrangement comprises shielding units (131) which partially overlap and define gas flow paths (132) therebetween; and coating a substrate (10) by sputtering material from the at least one sputter source (121) toward the substrate (10) arranged on a first side of the deposition source (120).

15. The method of claim 14, wherein the vacuum chamber (101) comprises a vacuum processing area (102) on a front side of the shielding arrangement (130) and a pumping area (103) on a rear side of the shielding arrangement (130), the method further comprising: removing gas from the pumping area (103) with one or more vacuum pumps, the gas flowing from the vacuum processing area (102) to the pumping area (103) through the shielding arrangement (130) along the gas flow paths (132).

16. The method of claim 14 or 15, wherein the gas flow paths (132) are labyrinth ducts in which a gas main flow direction is reversed at least once.