WO2015188879A1

WO2015188879A1 - Flat edge design for better uniformity and increased edge lifetime

Info

Publication number: WO2015188879A1
Application number: PCT/EP2014/062422
Authority: WO
Inventors: Simon Lau; Ralph Lindenberg; Markus Hanika
Original assignee: Applied Materials, Inc.
Priority date: 2014-06-13
Filing date: 2014-06-13
Publication date: 2015-12-17
Also published as: JP2017519109A; TWI652361B; KR20170016968A; TW201614082A; CN106460147B; CN106460147A; JP6357252B2; KR101942011B1

Abstract

An edge exclusion mask for layer deposition on a substrate is described. The edge exclusion mask includes an edge region with an edge, wherein the edge is adapted to have an inclination angle with respect to the substrate of 20° or less.

Description

FLAT EDGE DESIGN FOR BETTER UNIFORMITY AND INCREASED EDGE

LIFETIME

TECHNICAL FIELD OF THE INVENTION

[0001] Embodiments described herein relate to masks for layer deposition and methods and apparatuses for layer deposition utilizing masks. Embodiments described herein particularly relate to edge exclusion masks having a flat edge and methods and apparatuses of depositing layers with an edge exclusion mask having a flat edge, specifically to mask structures configured for deposition of a layer on a substrate, apparatuses for depositing a layer on a substrate and methods of depositing a layer over a substrate.

BACKGROUND OF THE INVENTION [0002] Several methods are known for depositing a material on a substrate. For instance, substrates may be coated by a physical vapor deposition (PVD) process, a chemical vapor deposition (CVD) process, a plasma enhanced chemical vapor deposition (PECVD) process etc. The process is performed in a process apparatus or process chamber, where the substrate to be coated is located. A deposition material is provided in the apparatus. A plurality of materials, but also oxides, nitrides or carbides thereof, may be used for deposition on a substrate.

[0003] Coated materials may 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. Further applications include insulating panels, organic light emitting diode (OLED) panels, substrates with TFT, color filters or the like.

[0004] In coating processes, it may be useful to use masks, for instance, in order to better define the area to be coated. In some applications, only parts of the substrate should be coated and the parts not to be coated are covered by a mask. In some applications, such as in large area substrate coating apparatuses, it can be useful to exclude the edge of the substrate from being coated. With the exclusion of the edge, e.g. by an edge exclusion mask, it is possible to provide coating free substrate edges and to prevent a coating of the backside of the substrate. For example, LCD TV layer deposition, as one of many other applications, requires a non-coated substrate edge. The above-described mask covers this area of the substrate. The masking or blocking with the mask can, however, result in further, additional shadowing effects of arriving atoms, molecules and clusters, which can result in the layer thickness being unreliable and sheet resistance uniformity.

[0005] However, the mask in a material deposition process, which may be an edge exclusion mask, is also exposed to the deposition material due to the location of the mask in front of the substrate. The influences of the non-coated and coated masks can be complex and may depend upon the material to be deposited.

[0006] In view of the above, embodiments described herein provide a mask, particularly an edge exclusion mask, an apparatus for layer deposition comprising an edge exclusion mask, and a method for masking the edges of a substrate which could overcome at least some of the problems in the art.

SUMMARY OF THE INVENTION

[0007] In light of the above, an edge exclusion mask, an apparatus and a method for layer deposition on a substrate according to independent claims 1, 11 and 13 are provided. Further aspects, advantages, and features of the present embodiments are apparent from the dependent claims, the description and the accompanying drawings. [0008] According to one embodiment, an edge exclusion mask for layer deposition on a substrate is provided. The edge exclusion mask includes an edge region with an edge, wherein the edge is adapted to have an inclination angle with respect to the substrate of 20° or less. [0009] According to a second embodiment, an edge exclusion mask for layer deposition on a substrate is provided. The edge exclusion mask includes an edge region with an edge, wherein the edge is adapted to have an inclination angle with respect to the substrate of 20° or less, further wherein the edge region has a thickness of 3 mm or less, particularly a thickness of 2 mm or less, at a distance of 5 mm from the edge. [0010] According to another embodiment, an apparatus for layer deposition on a substrate is provided. The apparatus includes a chamber for layer deposition, an edge exclusion mask comprising an edge region with an edge, wherein the edge is adapted to have an inclination angle with respect to the substrate of 20° or less; and a deposition source for depositing material forming the layer. [0011] According to a further embodiment, a method for layer deposition on a substrate is provided. The method includes masking a portion of the substrate with an edge exclusion mask, wherein the edge exclusion mask comprises an edge region with an edge, wherein the edge is adapted to have an inclination angle with respect to the substrate of 20° or less; and depositing material of the layer on the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] So that the manner in which the above recited features of the present embodiments can be understood in detail, a more particular description of the embodiments of the invention, briefly summarized above, may be had by reference to embodiments. The accompanying drawings relate to embodiments of the invention and are described in the following:

Fig. 1A shows a mask structure as commonly used for masking an edge of a substrate, according to the state of the art; shows a scenario of layer deposition on a common mask structure, in particular on an edge exclusion mask, according to the state of the art; shows an edge exclusion mask with a flat edge, according to embodiments described herein; shows a mask structure, such as an edge exclusion mask, according to embodiments described herein; shows a cross-sectional side view of a mask structure, in particular of an edge exclusion mask with a flat edge, according to embodiments described herein; shows a mask structure, such as an edge exclusion mask, according to embodiments described herein; shows a flow chart illustrating a method for layer deposition on a substrate, according to embodiments described herein; and shows an apparatus for layer deposition on a substrate utilizing an edge exclusion mask, according to embodiments described herein.

DETAILED DESCRIPTION OF EMBODIMENTS

[0013] Reference will now be made in detail to the various embodiments described herein, 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. Only the differences with respect to individual embodiments are described. Each example is provided by way of explanation of the embodiments and is not meant as a limitation of the embodiments. 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.

[0014] According to some embodiments, a mask structure or an "edge exclusion mask" should be understood as a mask which covers at least an edge of the substrate to be coated. A mask may be composed of several parts or portions, which can form a frame, which defines one or more apertures. The frame of a mask may again have several frame portions or frame parts. This may be advantageous as frames assembled from different parts are believed to be more cost efficient in production than integral frames. [0015] An edge exclusion mask is desirable when the edge of a substrate should be kept free or substantially free from deposition material. This may be the case when only a defined area of the substrate should be coated due to the later application and/or handling of the coated substrate. For instance, a substrate which will be used as a display part, should have predefined dimensions. Large area substrates are coated using an edge exclusion mask in order to shadow the edge of the substrate and/or to prevent backside coating of the substrate. This approach allows for reliable, constant coating on substrates.

[0016] According to embodiments described herein, an edge exclusion mask includes an edge region with an edge. Thereafter, the edge is adapted to have an inclination angle with respect to the substrate of 20° or less. Accordingly, if deposition material is deposited on the mask, the boundary of the aperture is less influenced by the deposited material on the mask. According to further embodiments, apparatus and methods comprise an edge exclusion mask as described above.

[0017] Accordingly, embodiments described herein allow reducing shadowing effects and by this, provide homogeneity of the coating on the substrate and increased edge lifetime when using an edge exclusion mask in deposition processes.

[0018] According to some embodiments, large area substrates may have a size of at least 0.67 m². The size can be about 0.67 m² to about 8 m², more particularly about 2 m² to about 9 m² or even up to 12 m². The substrates for which the mask structures, apparatuses and methods according to embodiments described herein are provided are 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 5.7 m² substrates (2.2 m x 2.5 m), or even GEN 10, which corresponds to about 8.7 m² substrates (2.85 m x 3.05 m). Even larger generations such as GEN 11 and GEN 12 and corresponding substrate areas can similarly be implemented.

[0019] A substrate may be made from any material suitable for material deposition. For instance, the substrate may be made from a material selected from the group consisting of glass (for instance soda-lime glass, borosilicate glass etc.), metal, polymer, ceramic, compound materials, carbon fiber materials or any other material or combination of materials which can be coated by a deposition process.

[0020] According to some embodiments, the term "mask structure", "edge exclusion mask" or "mask portion" is used for a piece of mask material, such as a carbon fiber material or a metal like aluminium, titan, stainless steel, Invar or the like. The mask covers a part of the substrate to be coated. The mask is located between the substrate to be coated and the source of the deposition material, such as a crucible, a target or the like.

[0021] An edge exclusion mask may cover from about l o to about 5% of the area of the substrate, particularly between about 5 %c to about 1% and even more particularly between about 1% and about 2% of the area of the substrate. According to some embodiments, the area of the substrate covered, shadowed or masked by the edge exclusion mask is located at the periphery of the substrate.

[0022] According to some embodiments, the term "mask aperture" should be understood as a window of a mask, through which the deposition material may pass during the deposition process. The "mask aperture" may also be denoted as a coating window as it defines the area of the substrate on which the coating material is deposited. The boundary or the inner boundary of the aperture is defined by the limitation of the coating window. For instance, if the mask is new or freshly cleaned and has not yet been used in a deposition process, the boundary of the aperture consists of mask material. If the mask is used in a deposition process and deposition material is deposited on the mask, the boundary of the aperture may be the limitation of the coating window by the deposited material on the mask.

[0023] According to different embodiments, an edge exclusion mask can be utilized for PVD deposition processes, CVD deposition process or combinations thereof. The edge of the mask may influence atoms, molecules and clusters in the vicinity thereof. These effects can be more complex as the "stream of material" can be affected by turbulences or the like and the edge cannot necessarily be regarded as a sharp cut-off edge. Particularly the more complex effects superimpose from neighboring side portions at the corners. [0024] FIG. 1A shows an example of a substrate 100. An outermost border of the substrate is denoted with 110. The border 110 may also be described as the outermost line of the substrate, beyond which the material of the substrate ends. An edge 120 of the substrate may contain the periphery of the substrate. The edge 120 as used herein may be an area containing the border 110 of the substrate. The edge 120 may have a width W, which extends onto the surface of the substrate 100 from the border 110. This edge 120 may be defined on a processed substrate by the edge exclusion mask 140, which is utilized during deposition of one or more layers on the substrate 100. The edge 120 defines an overlap between the edge exclusion mask and the substrate.

[0025] The width W may be symmetrical for the whole substrate, i.e. each corner area and each side portion has the same width, but may also vary from side to side, depending on the application of the substrate. According to some embodiments, the edge of the substrate may be defined by the aperture of the mask used for coating the substrate. For instance, the aperture of an edge exclusion mask influences the area of the substrate which is coated and covers an area of the substrate such as the edge. Thus, the edge of a substrate may be defined as the area of the substrate which is covered by the edge exclusion mask and which is not coated during the coating process in which the edge exclusion mask is used.

[0026] The mask reduces or hinders deposition of materials on the edge of a substrate. The masking or blocking with the mask can, however, result in further, additional shadowing effects of arriving atoms, molecules and clusters, which can result in an unreliable layer thickness and sheet resistance uniformity. Especially the four corners of the substrate are affected by additional shadowing effects because two shadowing parts meet each other at these points.

[0027] In FIG. IB, a layer generation on mask 140 is illustrated. The mask is covered with a continuous layer 400 after one or more deposition processes, wherein the lines indicate the growths of deposition material on the mask 140. After a first period of deposition, layer 401 is formed over the mask 140. The layer 401 will be coated on the surface of the mask facing a deposition source arrangement. A second period of deposition results in layer 402, wherein the layer 402 extends into the edge of the mask in a higher amount than layer 401. The layer 402 will result in a further growth of the overlapping region between the substrate and the mask. This growth provokes a shadowing effect on the substrate which results in an unreliable layer thickness, unreliable sheet resistance uniformity and lifetime reduction of the mask edge. The same outcome applies to a third period of deposition which results in layer 403. It is to be understood that even though FIG. IB refers to three deposition periods resulting in three layers on the mask, this concept of shadowing layers is a continuous process.

[0028] In view of the foregoing, FIG. IB illustrates a problem that might occur when using conventional edge exclusion masks during a deposition process. Accordingly, due to deposition of material on the mask, the boundary of the mask aperture is influenced by the deposited material on the mask resulting in a shadow effect. Furthermore, vibrations or other acceleration of the masking arrangement, e.g., during masking of a substrate in a carrier, result in particle generation from the coating layer 400. The particle generation cannot be controlled, such that there is a likelihood that undesired particles are also applied to a substrate surface to be processed. Accordingly, the design of the mask structure, and particularly of the edge of the mask, can result in undesired effects during maintenance and/or during the processing of substrates.

[0029] The edge design of the embodiments described herein has a very flat shape in the near substrate area. Accordingly, if deposition material is deposited on the mask, the boundary of the aperture is less influenced by the deposited material on the mask. As a result, embodiments described herein allow reducing shadowing effects and provide homogeneity of the coating on the substrate and increased edge lifetime when using an edge exclusion mask in deposition processes.

[0030] Accordingly, the edge design of embodiments described herein, illustrated in FIG. 2A, reduces the influence of the edge contour/shape and allows better uniformity and increased edge lifetime compared to conventional edge designs. [0031] With respect to FIG. 2A, an edge exclusion mask 240 for layer deposition on a substrate 100 comprising an edge region 201 with an edge 200 is shown. The edge region 201 corresponds to the region of the mask neighbouring with the substrate, which ends on an edge 200. The edge 200 is preferably a flat edge, as used herein, "flat edge" refers to a shallow, low thickness edge. A first surface 210 facing the substrate and an opposing surface 220 facing a deposition source arrangement are also shown. The first surface is adapted to receive different arrangements, such as a support arrangement, a protection shield, a substrate carrier or a cooling frame. The opposing surface may protect the underlying arrangements from being coated. The opposing surface may be exposed to a deposition source and coated by a deposition material forming a layer of coated material on the edge exclusion mask 240. As indicated in FIG. 2A, one or more different regions can be provided within edge exclusion mask 240. For instance, a peripheral region 203 may correspond to the region of the mask extending from the outer perimeter of the mask. A further region, e.g. the intermediate region 202, may correspond to the region of the mask extending between the edge region 201 and the peripheral region 203. According to alternative embodiments, the intermediate region might be avoided. By avoiding the intermediate region, the peripheral region 203 may correspond to the region of the mask extending from the outer perimeter of the mask to the edge region 201.

[0032] Accordingly, present embodiments reduce or eliminate any inhomogeneity of the coating on the substrate, preferably in the outer regions of the substrate, by reducing or eliminating shadowing effects that may occur when the edge region of the mask has a too large thickness. For instance, the edge design of the embodiments described herein provides a coating uniformity of 5 % in 10 mm distance to the edge.

[0033] Yet, according to further embodiments, the edge of the edge exclusion mask may have an inclination angle with respect to the substrate of 20° or less, particularly the edge may have an inclination angle with respect to the substrate of 15° or less, more particularly the edge may have an inclination angle with respect to the substrate of 10° or less. The inclination angle of the edge may be chosen in view of the geometry and directional characteristics of the deposition source. [0034] According to different embodiments, which can be combined with other embodiments described herein, the edge region of the edge exclusion mask may have a thickness of 3 mm or less, particularly the edge region may have a thickness of 2 mm or less, more particularly the edge region may have a thickness of 1 mm, at a distance of 5 mm from the edge.

[0035] According to some embodiments, which can be combined with other embodiments described herein, the opposing surface 220 may have two or more different inclination angles with respect to the first surface 210. Yet, according to different embodiments, the two or more different inclination angles may be between 0° and 70°, particularly the two or more different inclination angles may be between 10° and 50°, more particularly the two or more different inclination angles may be between 20° and 45°. [0036] An edge exclusion mask with two or more different inclination angles has the advantage of providing sufficient height and at the same time providing a low thickness edge region with a flat edge. A sufficient height of the edge exclusion mask is necessary for receiving different arrangements, such as a support arrangement, a protection shield, a substrate carrier or a cooling frame. A low thickness edge region with a flat edge reduces or eliminates any inhomogeneity of the coating on the substrate by reducing or eliminating shadowing effects that may occur when the edge region of the mask has a too large thickness, as is the case with current edge exclusion masks having only one inclination angle. A low thickness edge region with a flat edge further increases the edge lifetime.

[0037] According to different embodiments, which can be combined with other embodiments described herein, the peripheral region may have an inclination angle with respect to the substrate of 5° or less, particularly the peripheral region may have an inclination angle with respect to the substrate of 2° or less, more particularly the peripheral region may have an inclination angle with respect to the substrate of 0°. According to further embodiments, the intermediate region may have an inclination angle with respect to the substrate of 30° to 70°, particularly the intermediate region may have an inclination angle with respect to the substrate of 40°to 60°, more particularly the intermediate region may have an inclination angle with respect to the substrate of about 45°.

[0038] After a predetermined number of deposition runs, the coated material on the mask, more particularly on the opposing surface of the mask, may detach forming particles that migrate in a uncontrolled manner, e.g. onto the substrate or other parts of the deposition facility. These particles may have detrimental effects on the processed substrates, in cases may even destroy them.

[0039] According to embodiments described herein, in order to compensate for this effect, a mask with protrusions on its surface is provided which may reduce detaching of particles. FIG. 2B shows an edge exclusion mask 240 having an opposing surface 220. The opposing surface 220 may comprise protrusions 215, particularly 70 % or more of the opposing surface may comprise protrusions, more particularly 90 % or more of the opposing surface may comprise protrusions. As indicated in FIG. 2B, the edge exclusion mask 240 may be composed of two or more mask portions which can form a frame. When the edge exclusion mask 240 is composed of two or more mask portions, the first surface 210 may be adapted to facilitate engagement of the two or more mask portions by a connecting part 260, as shown in FIG. 2A. The two or more mask portions may further have an adjustable overlapping region between the two or more mask portions.

[0040] FIG. 3 illustrates a side view of a substrate 100, and wherein the edge of the substrate is shadowed by a mask 240. The mask is provided to have a gap 300 of 2 mm to 8 mm from the substrate, i.e. the portion of the mask shadowing the substrate surface is not in contact with the substrate surface. According to other embodiments, the mask can also be in direct contact with the substrate, e.g. there can be no gap or the gap can be from 0 mm to 8 mm. The arrows 305 in FIG. 3 illustrate coating material to be deposited during deposition.

[0041] According to further embodiments, which can be combined with other embodiments described herein, the thickness uniformity at the corners of the coated area of a substrate can be improved by an edge exclusion mask with cut-outs at the corners. As a result, shadowing effects of an edge exclusion mask at the corners, which can add up and which can, thus, result in an insufficient layer thickness, can be reduced.

[0042] As indicated in FIG. 4, an edge exclusion mask 240 with an aperture in the middle of the mask frame can be provided. The aperture can have a protrusion, i.e. compared to the rest of the mask, the mask frame in the four corners can have a recess or a cut out. This is for example illustrated in corner areas 442, wherein the width Wc of the overlap of the mask 240 and the substrate, i.e. the distance of the boundary of the mask forming the aperture and the edge 110 of the substrate, is smaller in the corner areas 442 as compared to the width Ws of the overlap of the mask 240 and the substrate, i.e. the distance of the boundary of the mask forming the aperture and the edge 110 of the substrate, at the side portions 440 of the mask frame. Corner areas 442 can have a length L and a width H, which can, for example be 2 cm to 6 cm, preferably 3 cm to 5 cm. According to different implementations, the length and the width can be equal at the respective sides or they can be different. For example they can have about the same proportion of the overall side length of the respective mask.

[0043] According to some embodiments, which can be combined with other embodiments described herein, the first overlap, i.e. the first width Ws can be from 2 mm to 8 mm, particularly from 3 mm to 6mm. As a further optional implementation thereof the second overlap, i.e. the width Wc can be from 0.0 mm to 4 mm, particularly from 1 mm to 3 mm. The edge of a substrate may be defined as an area of the substrate which should be kept substantially free of deposition material or where the layer thickness of deposited material is reduced to a value of at least 25 % as compared to the un-masked substrate portion.

[0044] According to some implementations thereof, it is even possible that there is a negative overlap, i.e. a gap, in the corner areas. Yet, according to further embodiments, one can have an area on the substrate, which is deposited within the non-coated or substantially non-coated edge of the substrate, wherein the deposited area has a rectangular shape. Accordingly, an edge exclusion mask is provided, which slightly deviates from the rectangular form in order to compensate for higher order shadowing effects in the corners.

[0045] An edge exclusion mask according to the embodiments described herein, having a low thickness edge region with a flat edge, may present lower stability than an edge exclusion mask having a higher thickness. According to some embodiments, which can be combined with other embodiments described herein, the edge exclusion mask may include one or more rips spaced apart along mask perimeter. The rips have the advantage of raising form stability of the mask structure. Accordingly, the edge exclusion mask of the present embodiments allows for stability regardless of the low thickness edge region with a flat edge. [0046] According to some embodiments, which can be combined with other embodiments described herein, the edge exclusion mask may rise as an L- shaped member, e.g. a thin member such as with a thickness of 10 mm or below, towards the cooling frame where it is attached. The L- shape may allow connection of the mask to the adaptor to the cooling frame.

[0047] According to further embodiments, a method is provided for depositing a layer of material on a substrate. FIG. 5 shows a flow diagram of the described method. A substrate may be provided in a chamber of a deposition apparatus. According to some embodiments, the substrate may be a large area substrate as described above and the deposition apparatus may be a deposition chamber as exemplarily shown in FIG. 6.

[0048] A masking arrangement is moved towards the substrate within the chamber 612 and a portion of the substrate, e.g. an edge of the substrate, is covered by a mask 502. The masking is, according to embodiments described herein, provided with an edge exclusion mask comprising an edge region with an edge as described herein. The mask provides an aperture with protrusions which allows deposition material to pass through during a deposition process. Examples of such an edge exclusion mask are described with respect to FIGS. 2A to 4. After masking of the substrate, a layer is deposited 504, such that shadowing effects are reduced, therefore allowing better uniformity of the coating on the substrate and increased edge lifetime, since the edge is kept free of or substantially free of deposited material.

[0049] According to some embodiment, which can be combined with other embodiments described herein, the method for depositing a layer of material on a substrate and the mask for covering an edge of the substrate are used for large area substrates. According to further embodiments, the deposited layer is a metal layer or a ceramic layer. [0050] FIG. 6 shows a schematic view of an apparatus for layer deposition on a substrate according to embodiments described herein. The deposition apparatus 600 is adapted for a deposition process, such as a PVD or CVD process and includes a chamber 612 for layer deposition. One or more substrates 100 are shown being located on a substrate transport device 620. According to some embodiments, the substrate support may be movable to allow for adjusting the position of the substrate 100 in the chamber 612. Particularly for large area substrates as described herein, the deposition can be conducted having a vertical substrate orientation or an essentially vertical substrate orientation. The transport device can have lower rollers 622, which are driven by one or more drives, e.g. motors. The drives can be connected to a roller 622 by a shaft for rotation of the roller so that it is possible that one motor drives more than one roller, e.g. by connecting rollers with a belt, a gear system, or the like.

[0051] Rollers 624 can be used for support of the substrates in the vertical or essentially vertical position. The substrates can be vertical or can slightly deviate from the vertical position, e.g. up to 5°. Large area substrates having substrate sizes of 1 m 2 to 9 m 2 are very thin, e.g. below 1 mm, such as 0.7 mm or even 0.5 mm. In order to support the substrate and to provide the substrates in fixed position, the substrates are provided in a carrier during processing of the substrates. Accordingly, the substrates can be transported by the transport system including, e.g., a plurality of rollers and drives while being supported in a carrier. For example, the carrier with the substrates therein is supported by the system of rollers 622 and rollers 624.

[0052] A deposition material source (not shown) is provided in chamber 612 facing the side of the substrate to be coated. The deposition material source provides deposition material to be deposited on the substrate. According to embodiments described herein, the deposition material source may be a target with deposition material thereon or any other arrangement allowing material to be released for deposition on substrate 100. The material source may be a rotatable target. According to some embodiments, the material source may be movable in order to position and/or replace the source. According to other embodiments, the material source may also be a planar target.

[0053] According to some embodiments, the deposition material may be chosen according to the deposition process and the later application of the coated substrate. For instance, the deposition material of the source may be a material selected from the group consisting of: a ceramic material, a metal, such as aluminum, molybdenum, titanium, copper, or the like, silicon, indium tin oxide, and other transparent conductive oxides. Oxide-, nitride- or carbide-layers, which can include such materials, can be deposited by providing the material from the source or by reactive deposition, i.e. the material from the source reacts with elements like oxygen, nitride, or carbon from a processing gas. According to some embodiments, thin film transistor materials like siliconoxides, siliconoxynitrides, siliconnitrides, aluminumoxide, aluminumoxynitrides may be used as deposition material.

[0054] The deposition apparatus 600 includes a masking arrangement including a mask structure 240. According to some embodiments, the mask 240 is an edge exclusion mask including an edge region 201 with an edge 200, wherein the edge is adapted to have an inclination angle with respect to the substrate of 20° or less. The edge exclusion mask ensures that the edges of the substrate 100 are not coated with deposition material. As an example, the material is sputtered or can also be vaporized. According to embodiments described herein, an edge of the substrate 100 remains free of deposition material due to the edge exclusion mask 240.

[0055] In FIG. 6, the left edge exclusion mask is illustrated to include individual frame portions 601,602,603,604,605, 606, 607, 608, 609 and 610 which are connected to form the mask frame. A mask structure particularly for large area substrates will be provided with by at least 4 corner portions 601,603,606, and 608, which can be essentially L-shaped and which will include the corner area or at least a significant portion of the corner area, and with side portions, which connect the corner parts to form the mask frame. The frame portions 601-610 may be arranged in a tongue-and-groove arrangement. The tongue-and- groove arrangement provides fixed positions of the frame portions relatively to one another. Further, according to some embodiments described herein, the tongue-and-groove arrangements of the frame portions allow the movement of the frame portions away from each other. A tongue-and-groove arrangement enables the frame portions to slide away from each other without causing a gap through which deposition material could pass. For reasons of simplicity, only the left mask structure 240 is shown with portions 601-610. Similarly more than one or all mask structures in a processing system can be provided with more than one portion to form the mask frame.

[0056] According to typical embodiments, which can be combined with other embodiments described herein, the one or more chambers 612 can be provided as vacuum chambers. The chambers are adapted for processing and/or coating the substrates in vacuum environment. The pressure can be below 10 mbar, e.g. between lx 10-7 mbar and 1x10-1 mbar. Thus, deposition system may include a pumping system (not shown), which can be connected to vacuum flanges 613, and capable of achieving a pressure within processing chamber 612 sufficiently low for enabling the deposition system to be operable for a particular application, such as a pressure of 1x10-7 mbar. The pressure during deposition, such as PVD processes, (i.e. deposition pressure) may be between 0.1 Pa and 1 Pa. For particular embodiments, e.g. PVD applications, wherein the processing gas includes argon and at least one of oxygen or nitrogen, the argon partial pressure may be between 0.1 Pa and 1 Pa, and the oxygen, hydrogen and/or nitrogen partial pressure may be between 0.1 Pa and 1 Pa. The pressure ranges for CVD applications can be about 2 orders of magnitude larger, particularly at the high pressure end of the ranges given above.

[0057] According to some embodiments, which can be combined with other embodiments described herein, the method and apparatus for layer deposition on a substrate comprise an edge exclusion mask as described above with respect to FIGS. 2A to 4.

[0058] While the foregoing is directed to embodiments described herein, other and further embodiments may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

1. An edge exclusion mask (240) for layer deposition on a substrate (100) comprising an edge region (201) with an edge (200), wherein the edge is adapted to have an inclination angle with respect to the substrate of 20° or less.

2. The mask of claim 1, wherein the edge region (201) has a thickness of 3 mm or less, particularly a thickness of 2 mm or less, at a distance of 5 mm from the edge (200).

3. The mask of any of the preceding claims, wherein the mask comprises a first surface (210) facing the substrate and an opposing surface (220) facing a deposition source arrangement, wherein the opposing surface (220) has two or more different inclination angles with respect to the first surface (210).

4. The mask of claim 3, wherein the two or more different inclination angles are between 0° and 70°.

5. The mask of any of the preceding claims, further comprising an intermediate region (202).

6. The mask of claim 5, wherein the intermediate region has an inclination angle of 40° to 60°.

7. The mask of any of the preceding claims, further comprising a peripheral region (203).

8. The mask of any of the preceding claims, wherein the surface of the mask comprises protrusions (215).

9. The mask of any of the preceding claims, comprising two or more mask portions (601-610), wherein the two or more mask portions have an overlapping region, wherein the overlapping region between the two or more mask portions is adjustable.

10. The mask of any of the preceding claims, wherein the mask comprises one or more rips spaced apart along the mask perimeter.

11. A method for layer deposition on a substrate, comprising:

masking a portion of the substrate with an edge exclusion mask (240), wherein the edge exclusion mask comprises an edge region (201) with an edge (200) according to any of claims 1 to 10; and

depositing material of the layer on the substrate.

12. The method of claim 11, wherein the deposited layer is a metal layer or a ceramic layer. An apparatus (600) for layer deposition on a substrate, comprising:

a chamber (612) for layer deposition therein,

an edge exclusion mask (240) comprising an edge region (201) with an edge (200) according to any of claims 1 to 10; and

a deposition source for depositing material forming the layer.

The apparatus of claim 13, wherein the deposition source is configured to deposit a metal or a ceramic material.