ARRANGEMENT

TECHNICAL FIELD

[0001] Embodiments relate to holding a substrate, e.g. in a carrier for substrate processing, with an adhesive, such as a dry adhesive. For example, the dry adhesive can be a synthetic setae material, which may also be referred to as a gecko material. Embodiments of the present disclosure particularly relate to a holding arrangement for holding a substrate during substrate processing in a vacuum processing chamber, a carrier for holding a substrate in a vacuum processing chamber, a vacuum processing system including a deposition source, and a method for releasing a substrate after substrate processing, particularly for substrates with a narrow thickness and a large area.

BACKGROUND

[0002] Coated materials can be used in several applications and in several technical fields. For instance, coated materials may be used in the field of microelectronics, such as for generating semiconductor devices. Also, substrates for displays can be coated. Further applications include insulating panels, organic light emitting diode (OLED) panels, substrates with thin film transistors (TFTs), color filters or the like.

[0003] Techniques for layer deposition on a substrate include, for example, thermal evaporation, chemical vapor deposition (CVD) and physical vapor deposition (PVD) such as sputtering deposition. [0004] There is a trend in recent years towards larger and also thinner substrates. Particularly for fields such as display production, manufacturing of thin-film solar cells and similar applications, large area glass substrates are processed.

[0005] The increasing size of such substrates makes the handling, supporting and processing thereof, without sacrificing the throughput by breakage, increasingly challenging.

[0006] Substrates, such as glass substrates, can be mounted on carriers during processing. A carrier drives the substrate or the glass through the processing system. The carriers can form a frame or a plate, which supports a substrate, e.g. along the periphery of the substrate. Particularly, a frame shaped carrier can also be used to mask a glass substrate, wherein the aperture in the carrier, which is surrounded by the frame, provides an aperture for coating material to be deposited on the exposed substrate portion or an aperture for other processing actions acting on the substrate portion, which is exposed by the aperture. [0007] Due to the tendency towards larger and also thinner substrates, clamping and holding of the substrates by the carriers represents a major challenge. For example, substrates of such increased size and decreased thickness are transported through the manufacturing system in a vertical position. There is a need for exact positioning of the substrates inside the carriers, for example relative to a mask provided by or connected to the carrier. Further, a reliable holding mechanism is needed in order to avoid that the substrates stand on a lower edge. At the same time, there is a need for a non-hazardous method of releasing the substrates once a processing is completed.

[0008] In light of the foregoing, there is a need to provide holding arrangements for holding a substrate, carriers for supporting a substrate, processing systems, and methods for holding and for releasing a substrate from a holding arrangement that overcome at least some of the problems in the art. SUMMARY

[0009] In light of the above, a holding arrangement for holding a substrate, a carrier for holding a substrate, a processing system, and a method for holding and for releasing a substrate from a holding arrangement are provided. Further aspects, benefits, and features of the present disclosure are apparent from the claims, the description, and the accompanying drawings.

[0010] According to an aspect of the present disclosure, a holder for holding a substrate is provided. The holder includes a surface configured to face the substrate and an adhesive provided over the surface and comprising a plurality of adhesive structures. The plurality of adhesive structures include a first adhesive structure protruding from the surface and a second adhesive structure protruding from the surface; the first adhesive structure bends differently when bent in a given direction compared to the second adhesive structure when bent in the same direction with the same force. [0011] According to another aspect of the present disclosure, a holder for holding a substrate is provided. The holder includes a surface configured to face the substrate; and an adhesive provided over the surface and comprising a plurality of adhesive structures. The plurality of adhesive structures includes: A first adhesive structure protruding from the surface and a second adhesive structure protruding from the surface. The first adhesive structure and the second adhesive structure have an anisotropic flexibility parallel to the surface and the directions of minimal flexibility of the first adhesive structure and the second adhesive structure are different.

[0012] According to another aspect of the present disclosure, a holder for holding a substrate is provided. The holder includes a surface configured to face the substrate; and an adhesive provided over the surface and comprising a plurality of adhesive structures. The plurality of adhesive structures comprising: A first adhesive structure protruding from the surface and having a first elongated cross-section and a second adhesive structure protruding from the surface and having a second elongated cross- section. The first elongated cross-section has a first orientation and the second elongated cross-section has a second orientation different from the first orientation.

[0013] According to yet another aspect of the present disclosure, a carrier for holding a substrate is provided. The carrier includes a carrier body, and one or more holders as disclosed herein.

[0014] According to a further aspect of the present disclosure, a processing system is provided. The processing system includes a processing chamber, a processing device and a carrier as disclosed herein.

[0015] According to another further aspect of the present disclosure, a method for holding a substrate using a holder is provided. The method includes mounting a substrate on a carrier having a holder with an adhesive comprising a plurality of adhesive structures and positioning the carrier, wherein a majority of the directions of minimal flexibility of individual adhesive structures are in the vertical direction or in a direction between +30° and -30° from the vertical direction. [0016] According to yet a further aspect of the present disclosure, a method for releasing a substrate from a holder with an adhesive comprising a plurality of adhesive structures is provided. The method includes applying a force to the holder such that, for a majority of adhesive structures on the holder, the force is directed in a direction of maximum flexibility of the adhesive structures or in a direction of between +30° and -30° from the direction of maximum flexibility of the adhesive structures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] So that the manner in which the above recited features can be understood in detail, a more particular description of the disclosure, 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 front view of a carrier according to embodiments described herein;

FIG. 2A shows a schematic cross- sectional side view of a holder according to a comparative embodiment having a holder supporting a substrate;

FIG. 2B shows a schematic cross-sectional side view of a holder according to embodiments described herein having a holder supporting a substrate;

FIG. 2C shows a schematic front view of a cross-section of an individual gecko structure according to embodiments described herein;

FIG. 3 shows a schematic cross-sectional side view of a holder according to embodiments described herein;

FIG. 4 shows a schematic top view of a holder according to embodiments described herein;

FIG. 5 shows a schematic top view of a holder according to embodiments described herein;

FIG. 6 shows a schematic top view of a holder according to embodiments described herein;

FIG. 7 shows a flow chart illustrating a method for releasing a substrate from a holder according to embodiments described herein;

FIG. 8 shows a method for holding and releasing a substrate from a holder according to embodiments described herein;

FIG. 9 shows a schematic view of a processing system according to embodiments described herein. DETAILED DESCRIPTION OF EMBODIMENTS

[0018] Reference will now be made in detail to the various embodiments, one or more examples of which are illustrated in each figure. Each example is provided by way of explanation and is not meant as a limitation. For example, features illustrated or described as part of one embodiment can be used on or in conjunction with any other embodiment to yield yet a further embodiment. It is intended that the present disclosure includes such modifications and variations.

[0019] Within the following description of the drawings, the same reference numbers refer to the same or to similar components. Generally, only the differences with respect to the individual embodiments are described. Unless specified otherwise, the description of a part or aspect in one embodiment applies to a corresponding part or aspect in another embodiment as well.

[0020] In the present disclosure, a holder is to be understood as an arrangement configured to hold a substrate, e.g. during substrate processing. In particular, the holder or holding arrangement can be configured to hold a large area substrate in a vertical state or an essentially vertical state. A holder as described herein can be an element of a carrier supporting a substrate during processing.

[0021] In the present disclosure, an adhesive is to be understood as a structure or arrangement which is configured for providing an adhesive force for attaching a substrate as described herein. In particular, the adhesive can be included in a holder, for example, the adhesive can be provided on the surface of a holder. Further, according to embodiments, which can be combined with any other embodiments described herein, the adhesive may include a dry adhesive material. The dry adhesive can be configured to attach the substrate to the holder. [0022] In the present disclosure, a carrier is to be understood as a carrier which is configured to hold a substrate, particularly a large area substrate. The substrate held or supported by or mounted to a carrier may include a front surface and a back surface. The front surface can be a surface of the substrate being processed, for example on which a material layer is to be deposited. The carrier can be configured to hold the substrate at the back surface of the substrate. For example, one or more holders of the carrier can be attached at an edge portion of the substrate.

[0023] The term substrate as used herein shall particularly encompass inflexible substrates, e.g., glass plates and metal plates. However, the present disclosure is not limited thereto and the term substrate can also encompass flexible substrates such as a web or a foil. According to some embodiments, the substrate can be made from any material suitable for material deposition. For instance, the substrate can 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, mica or any other material or combination of materials which can be coated by a deposition process. For example, the substrate can have a thickness of 0.1 mm to 1.8 mm, such as 0.7 mm, 0.5 mm or 0.3 mm. In some implementations, the thickness of the substrate may be 50 μιη or more and/or 700 μιη or less. [0024] According to some embodiments, the substrate can be a large area substrate and may be used for display manufacturing. For instance, the substrate may be a glass or plastic substrate. For example, substrates as described herein shall embrace substrates which can be used for an LCD (Liquid Crystal Display), a PDP (Plasma Display Panel), and the like. For instance, a large area substrate can have a main surface with an area of 0.5 m ² or larger, particularly of 1 m ² or larger. In some embodiments, a large area substrate can be GEN 4.5, which corresponds to about 0.67 m ² of substrate (0.73x0.92m), GEN 5, which corresponds to about 1.4 m ² of substrate (1.1 m x 1.3 m), GEN 7.5, which corresponds to about 4.29 m ² of substrate (1.95 m x 2.2 m), GEN 8.5, which corresponds to about 5.7 m ² of substrate (2.2 m x 2.5 m), or even GEN 10, which corresponds to about 8.7 m ² of substrate (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.

[0025] As exemplarily shown in FIG. 1, the substrate 101 can have an upper side 11, a lower side 12 and two lateral sides 13 (e.g., a left side and a right side). The upper side 11, the lower side 12 and the two lateral sides 13 can be defined with respect to a vertical orientation of the substrate 101. For example, the apparatuses described herein can be configured to essentially vertically support the substrate during processing thereof. Likewise, the carrier 100 or carrier body 110 can have an upper side, a lower side and two lateral sides (e.g., a left side and a right side). The carrier body 110 can be a rigid body, such as a frame, a bar, or a plate, which is e.g. configured to hold a substrate 101. For large area substrates, the carrier 100 or carrier body 110 can be manufactured having several portions.

[0026] FIG. 1 shows a schematic front view of an embodiment of a carrier 100 according to the present disclosure. According to embodiments, which can be combined with any other embodiments described herein, the carrier 100 includes a carrier body 110 and one or more holders 200. The one or more holders 200 are mounted on the carrier body 110. For instance, the one or more holders 200 can be connected to a support structure or body. The support structure or body (see FIG. 3) can be connected to the carrier body 110. The one or more holders 200 are configured to provide a holding force to hold the substrate 101. For instance, a holding force can be parallel to a surface of the substrate 101 when the substrate is in a substantially vertical orientation. For instance, the holding force can be provided by the adhesive 230 of the holder 200. [0027] In some implementations, the one or more holders 200 can be mounted on the carrier body 110 to hold at least the upper side 11, or at least one of the upper side 11, the lower side 12, and at least one of the two lateral sides 13 of the substrate 101. For instance, as exemplarily shown in FIG. 1, one or more holders 200 (e.g., 6 or more such as 10 or more holders, two holders are shown in FIG. 1) can be provided to hold the upper side 11. According to another implementation, one or more holders 200 (e.g., 6 or more such as 10 or more holders, two holders are shown in FIG. 1) can be provided to hold the lower side 12 of the substrate. One or more holders 200 can be provided to hold each side of the two lateral sides 13 (e.g., six or more holders for the left side and six or more holders for the right side). [0028] According to embodiments, which can be combined with any other embodiments described herein, the carrier 100 can be configured to support the substrate 101 during substrate processing, for example, during a layer deposition process, such as a sputtering process. It is to be understood that a carrier according to embodiments described herein can be employed for stationary processes as well as for non- stationary processes, i.e. dynamic processes.

[0029] FIG. 2A shows a schematic cross- sectional side view of a holder 200' according to a comparative embodiment in a position supporting a vertical substrate 101. FIG. 2B shows a schematic cross- sectional side view of a holder 200 according to embodiments described herein in a position supporting a vertical substrate 101.

FIG. 2B represents a cross-sectional side view along the line A-A of the section of the carrier shown in FIG. 1.

In the holder 200' of FIG. 2A, gecko structures 300' have an isotropic flexibility, whereas in the holder 200 of FIG. 2B, gecko structures 300 have an anisotropic flexibility.

[0030] The authors of the present disclosure have identified that a substrate, which is, for example, attached in a horizontal direction, and which is subsequently positioned in a vertical direction on a holder may undergo sagging (e.g. as depicted in FIG. 2A by arrow "S"). Accordingly, there is a risk that the substrate stands on a lower edge due to substrate sagging. However, replacing the gecko structures of FIG.

2A by thicker or coarser structures bares the risk of making it impossible to release the substrate once the processing is completed. Surprisingly, however, the authors have solved the problem of substrate sagging while at the same time allowing for a safe substrate release after processing. [0031] According to embodiments, which can be combined with any other embodiments described herein, a holder 200 for holding a substrate 101 is disclosed. The holder 200 comprises a surface 210 configured to face the substrate 101. Further, the holder comprises an adhesive 230 provided over the surface. The adhesive comprises a plurality of adhesive (or gecko) structures 300. The plurality of adhesive structures comprises at least a first adhesive structure 301 protruding from the surface and at least a second adhesive structure 302 protruding from the surface. The first adhesive structure 301 and the second adhesive structure 302 have an anisotropic flexibility parallel to the surface 210. The direction of minimal flexibility of the first adhesive (or gecko) structure 321 and the direction of minimal flexibility of the second adhesive (or gecko) structure 322 can be different. According to embodiments described herein, the first adhesive structure bends differently when bent in a given direction compared to the second adhesive structure when bent in the same direction with the same force. [0032] The adhesive 230 can be configured for providing the adhesive force by van der Waals forces. Particularly, the adhesive can include a synthetic setae material. For example, the adhesive capabilities of the adhesive according to embodiments described herein can be related to the adhesive properties of a gecko foot. The natural adhesive capability of the gecko foot allows the animal to adhere to surfaces of many types under most conditions. The adhesive capability of the gecko foot is provided by numerous hair-type extensions, called setae, on the feet of the gecko. It is noted here that the term synthetic setae material is to be understood as a material which emulates the natural adhesive capability of the gecko foot and which includes similar adhesive capabilities to the gecko foot. Moreover, the term synthetic setae material may be synonymously used with the term synthetic gecko setae material or with the term gecko material, gecko tape material, gecko structure material, or with the term gecko structure. In this context, a gecko structure or adhesive structure is to be understood as a macro structure in form of setae, fiber, filament, or rod protruding from a holder, particularly from the surface of a holder. [0033] According to embodiments, which can be combined with any other embodiments described herein, the adhesive force provided by the adhesive can be sufficient for holding a substrate as described herein. In particular, the adhesive can be configured to provide an adhesive force of about 2 N/cm or more, particularly 3

N/cm 2 or more, more particularly 4 N/cm 2 or more, for instance at least 5 N/cm 2 or more. [0034] Further, the adhesive can include a flexible or elastic material. For example, the adhesive can include a hydrophobic, non-moisture absorbing material, particularly a silicon based material, such as silicon dioxide, or a polyimide based material and combinations thereof. Particularly, according to some embodiments, which can be combined with other embodiments described herein, the adhesive, such as the dry adhesive material, can comprise a silicon based or a polyimide based material or a combination of both.

[0035] In the present disclosure, the adhesive includes a plurality of gecko structures. For example, a gecko structure can be inorganic. According to embodiments described herein the gecko structure is substantially 100% inorganic. Moreover, the micro structure of the gecko structure typically includes silicon or polymide (PI). According to alternatives, the micro structure of the gecko structure includes carbon nanotubes.

[0036] According to yet further embodiments, it may be beneficial to utilize microstructures for the dry adhesive or the synthetic setae material, which does not provide enclosures for a gas upon contact with a substrate. Apparatuses for substrate processing, carriers, and holders, are configured for operation and the vacuum. A substrate may be attached to a holder under atmospheric pressure and may be loaded in a substrate processing system through a load lock chamber, which is evacuated after loading the substrate in the load lock chamber. Gas enclosures in the dry adhesive may result in the reduced holding force upon evacuation. Accordingly, the microstructures and/or nanostructures of the dry adhesive may essentially consist of solid material.

[0037] The term anisotropic flexibility as used herein shall encompass gecko structures having a directionally dependent flexibility, i.e. having a flexibility which is different in different directions. In general, flexibility can be regarded as a measure of susceptibility of an elastic body to a displacing force. According to embodiments described herein, a filament structure, hair-like structure or a tube-like structure is bent by a force acting lateral to the direction of the structure. An anisotropic flexibility refers to the degree of bending of the structures depending on the lateral direction of bending of the tube-like structures. For an elastic body with a single degree of freedom (DOF), flexibility can be defined by formula (1), wherein δ is the displacement produced by a force F along this DOF and F is the displacing force on the elastic body.

[0038] Flexibility =≤ (1)

[0039] For instance, a higher displacement value δ produced at the same force F implies a higher degree of flexibility of the elastic body. In this context, an anisotropic, directionally dependent flexibility refers to a different degree of flexibility, i.e. a different displacement value δ, depending on the direction of the displacing force F applied on the body.

[0040] According to embodiments described herein the flexibility, e.g. the anisotropic flexibility of adhesive structures can be parallel to surface 210 of the holder or the surface of the substrate. Further, the term direction of minimal flexibility as used herein shall encompass the direction in which an individual gecko structure 301, 302 exhibits a low flexibility parallel to the surface 210 of the holder. For instance, the term direction of minimal flexibility shall refer to the direction in which an individual gecko structure 301, 302 exhibits the lowest flexibility in any direction parallel to the surface 210. Further, the term direction of maximum flexibility as used herein shall encompass the direction in which an individual gecko structure 301, 302 exhibits a high flexibility parallel to the surface 210 of the holder. For instance, the term direction of maximum flexibility as used herein shall refer to the direction in which an individual gecko structure 301, 302 exhibits the highest flexibility in any direction parallel to the surface 210. [0041] In principle, anisotropic flexibility can be achieved in any suitable way envisioned by the person skilled in the art. For instance, anisotropy of flexibility may be the result of the internal composition of the gecko structure, such as texture patterns or internal fiber distribution. Further, anisotropic flexibility can be achieved, e.g., by the external shape of the gecko structure. For instance, the gecko structure may exhibit an elongated cross- section.

[0042] In the present disclosure, the term cross-section is to be understood as an intersection of the gecko structure 301, 302 with a plane substantially parallel to the surface 210 of the holder or to the surface of the substrate.

[0043] As exemplarily shown in FIG. 2C, the cross-section of a gecko structure can have an elongated shape. According to some embodiments, which can be combined with other embodiments described herein, the cross-section of the gecko structure can be allocated over at least 50% of the height 340 of the gecko structure. Additionally or alternatively, the cross- section being allocated over the height of the gecko structure may refer to a cross-section adjacent to the surface of the holder. The person skilled in the art is aware of many different elongated shapes. For instance, an elongated cross-section can be of an elliptic shape having a major and a minor extension or axis. Further, an elongated cross-section can be of a quadrangular shape having a major and a minor diagonal. Moreover, an elongated cross-section can be of a rectangular shape having a major and a minor lateral length. In this context, the terms major and minor relate to the dimension of length. For example, major relates to a length longer than a minor length.

[0044] According to embodiments, which can be combined with any other embodiments described herein, a holder 200 for holding a substrate 101 is disclosed.

The holder 200 comprises a surface 210 configured to face the substrate 101. Further, the holder comprises an adhesive 230 provided over the surface 210. The adhesive comprises a plurality of gecko structures 300.

[0045] Moreover, in the present disclosure, the plurality of gecko structures comprises a first gecko structure 301 protruding from the surface 210 and having a first elongated cross-section 311, and a second gecko structure 302 protruding from the surface 210 and having a second elongated cross-section 312. The first elongated cross-section 311 has a first orientation 321 and the second elongated cross-section 312 has a second orientation 322 different from the first orientation 321. [0046] The plurality of gecko structures comprises a first gecko structure protruding from the surface and having a cross-section with a first length (LI, e.g. as depicted in FIG. 2C by length "L") and a first width (Wl, e.g. as depicted in FIG. 2C by width "W"), wherein the ratio LI AVI is larger than 1; and a second gecko structure protruding from the surface and having a cross-section with a second length (L2) and a second width (W2), wherein the ratio L2/W2 is larger than 1. The first gecko structure has a first orientation and the second gecko structure has a second orientation different from the first orientation. For example, the directions of the longest dimension (corresponding to LI) of the first gecko structure and the longest dimension (corresponding to L2) of the second gecko structure are different.

[0047] According to embodiments, which can be combined with any other embodiments described herein, the holder can be of a substantially rectangular or circular shape.

[0048] With exemplary reference to FIG. 3, according to embodiments, which can be combined with any other embodiments described herein, the holder 200 can include a surface 210 configured to face the substrate 101. In the present disclosure, a surface configured to face the substrate can be understood as the surface of a body 211 or a support structure oriented substantially parallel to the substrate 101. The body 211 may include one or more layers. The body can include a flexible material. For example, the body can be made of silicone, a polymeric material, or particularly an elastomer. Alternatively, other flexible or elastic materials may be employed. According to embodiments, which can be combined with other embodiments described herein, the surface 210 may be made of a high temperature polymer. For instance, the high temperature polymer may have a temperature resistance of at least 150°C, particularly of at least 200°C, more particularly of at least 250°C, such as up to 300°C. For example, the surface may be made of at least one material selected from the group consisting of polyimide (PI), polyaryletherketone (PAEK), polyphenylensulfide (PPS), polyarylsulfone (PAS) and fluoropolymers (PTFE). [0049] As exemplarily indicated in FIG. 3, according to embodiments, which can be combined with any other embodiments described herein, the holder 200 can include a support structure or a body. Further, with exemplary reference to FIG. 3, the holder 200 can include an axis, which may for example be rotated as shown by arrow 240. For example, the rotatable axis 220 can be oriented perpendicular to the substrate 101.

[0050] As exemplarily shown in FIGS. 4, 5, and 6, according to embodiments, which can be combined with other embodiments described herein, a majority of gecko structures can be oriented such that the deviation angle a (FIG. 5) of the direction of minimal flexibility of an individual gecko structure 321, 322 to the radial direction 241 towards the rotatable axis 220 is less than 60°. More particularly, according to some embodiments, which can be combined with other embodiments described herein, the majority of gecko structures can be oriented such that the angle a between the direction of minimal flexibility 321, 322 of an individual gecko structure and the radial direction 241 to the rotatable axis 220 is within the range between and including 60° and 0°, such as 55°, 50°, 45°, 40°, 35°, 30°, 25°, 20°, 15°, 10°, 5° or less.

[0051] According to embodiments, which can be combined with any other embodiments described herein, the majority of gecko structures can refer to 50% or more of the total amount of gecko structures per individual holder. For example, the majority of gecko structures can refer to any of 55%, 60%. 65%, 70%, 75%, 80%, 85%, 90%, 95% or 99% or more of the total amount of gecko structures per individual holder.

[0052] For instance, as exemplarily shown in FIG. 4, gecko structures can be oriented radially, such that angles a _n between the direction of minimal flexibility of individual gecko structures n and the radial direction 241 to the rotatable axis 220 are 20° or less or substantially 0°.

[0053] According to embodiments, which can be combined with other embodiments described herein, the gecko structures of the holder can be oriented such that the holder provides less rotational than lateral resistance, such as less resistance against a twisting motion than against gravity with respect to a supported substrate.

[0054] As exemplarily shown in FIGS. 5, and 6, according to embodiments, which can be combined with other embodiments described herein, the holder 200 can include a plurality of adhesive structures comprising a plurality of first adhesive structures and a plurality of second adhesive structures. Particularly, according to some embodiments, the plurality of first adhesive structures can be provided over a first area 251 of the surface 210 and the plurality of second adhesive structures can be provided over a second area 252 of the surface 210 of the holder 200. More particularly, according to some embodiments, the first area 251 and the second area 252 can form a pattern. For example, the holder 200 can include more than two areas, such as three, four, five, six, seven, eight, nine, ten or more areas. For instance, as exemplarily shown in FIGS. 5, and 6, the pluralities of gecko structures of the holder can be arranged in four areas forming a chessboard like pattern. Each area can be characterized by a different orientation of the gecko structures. Moreover, the pattern can be arranged around a rotatable axis 220 on the surface of the holder 200. Particularly, according to embodiments, which can be combined with other embodiments described herein, the pattern can be a periodic pattern or a pattern rotationally symmetric around the rotatable axis 220 on the surface of the holder 200.

[0055] Accordingly, beneficially a holder for a substrate can be provided which is capable of conducting a method for holding as well as for releasing a substrate from the holder as described herein.

[0056] According to embodiments, which can be combined with any other embodiments described herein, a method for holding a substrate using a holder as described herein is disclosed. Particularly, the method of holding a substrate can include mounting a substrate on a carrier having a holder with an adhesive comprising a plurality of adhesive structures. Further, the method can include positioning the carrier in an essentially vertical orientation, e.g. from the mounting position to a vertical transport position, wherein the directions of minimal flexibility of the majority of gecko structures are in vertical direction or in a direction between +60° and -60°, between +45° and -45°, between +30° and -30°, more particularly between +15° and -15° from the vertical direction. [0057] In this context, the term vertical direction can be understood, for example, when referring to the substrate orientation, to allow for a deviation from the vertical direction or orientation of ±20° or below, e.g. of ±10° or below. This deviation can be provided for example because a substrate support with some deviation from the vertical orientation might result in a more stable substrate position, or in the event of the substrate slightly facing downward, in a reduced risk of particles contaminating the substrate surface. Yet, the substrate orientation, e.g., during the layer deposition process, can be considered substantially vertical, which can be considered different from the horizontal substrate orientation.

[0058] Further, the mounting can include attaching an adhesive to a surface of the holder, wherein the material of the adhesive is configured to attach the substrate to the surface of the holder. The mounting can include attaching the adhesive to the substrate. According to some embodiments, the adhesive is attached to the substrate before the adhesive is attached to the surface of the holder. According to other embodiments, which can be combined with other embodiments described herein, the adhesive is attached to the surface of the holder before being attached to the substrate. For example, the adhesive is configured to contact a first surface of the substrate, wherein said first surface may be the backside surface of the substrate.

[0059] Accordingly, beneficially, in the present disclosure, the method for holding a substrate using a holder as described herein substantially avoids sagging of the substrate irrespective of the mounting direction of the substrate with respect to the holder.

[0060] With exemplary reference to FIG. 7, embodiments of a method for releasing a substrate from a holder according to the present disclosure are described. A method for releasing a substrate from a mounted holder 401, with an adhesive comprising a plurality of gecko structures, includes applying a force to the holder 402 and releasing the holder 403. The force is applied such that for a majority of gecko structures on the holder the force is applied in the direction of maximum flexibility of gecko structures. For instance, the direction of maximum flexibility can be a direction perpendicular to the direction of minimal flexibility parallel to the surface of the holder. Particularly, according to embodiments, which can be combined with any other embodiments described herein, the method can include applying a force to the holder such that, for a majority of gecko structures on the holder, the force is applied in a direction between +60° and -60°, between +45° and -45°, between +30° and -30°, more particularly between +15° and -15°, such as between +5° and -5° from the direction of maximum flexibility of the gecko structures.

[0061] For example, according to some embodiments, which can be combined with other embodiments described herein, the force can be a rotational force applied around the rotatable axis 220 on the surface of the holder 200. The rotational force can be caused by a twisting motion of the holder against the substrate. According to some embodiments, which can be combined with other embodiments described herein, the twisting motion and the rotation of the holder can be parallel to the direction of maximum flexibility or perpendicular to the direction of minimal flexibility of the majority of the gecko structures. [0062] In the present disclosure, the method for releasing a substrate from a holder can include removal of the substrate 403 in order to obtain a free holder capable of mounting a further substrate.

[0063] The method for releasing a substrate from a holder can be conducted by computer programs, software, computer software products and interrelated controllers, which can have a CPU, a memory, a user interface, and input and output devices being in communication with the corresponding components of an apparatus for processing a substrate, such as the processing system described herein.

[0064] Accordingly, an improved method for releasing a substrate, particularly a large area substrate, from a carrier is provided. More specifically, the method as described provides for inducing shear forces at the interface between an adhesive of the holder and the substrate mounted thereon, such that the risk of damaging the substrate during releasing the substrate from the carrier can be reduced.

[0065] With exemplary reference to FIG. 8, the present disclosure provides a solution to the problem of substrate sagging when loaded on a carrier in a horizontal position and transferred in a vertical transport position, while at the same time allowing for a safe release of the substrate. The authors of the present disclosure have identified that a gecko structure having an anisotropic flexibility is able to avoid sagging, when the gravitational force is predominantly acting in the direction of minimal flexibility of the majority of the gecko structures A, while releasing can be done by applying a force in the direction of maximum flexibility of the majority of the gecko structures B.

[0066] According to some embodiments, a holder for holding a substrate can be provided. The holder includes a surface configured to face the substrate; and an adhesive provided over the surface and comprising a plurality of adhesive structures, the plurality of adhesive structures includes a first adhesive structure protruding from the surface, wherein the first adhesive structures has an anisotropic flexibility parallel to the surface. For example, the plurality of adhesive structures can have an anisotropic flexibility parallel to the surface. [0067] With exemplary reference to FIG. 9, a processing system 500 according to embodiments of the present disclosure is described. In the present disclosure, a processing system is to be understood as a system which is configured for processing a substrate. According to some embodiments, which can be combined with other embodiments described herein, the processing systems described herein are for vertical substrate processing. The term vertical substrate processing is understood to distinguish over horizontal substrate processing. That is, vertical substrate processing relates to an essentially vertical orientation of the substrate during substrate processing, and thus also the processing system, wherein a deviation of a few degrees, e.g. up to 10° or even up to 15°, from an exact vertical orientation is still considered as vertical substrate processing. A vertical substrate orientation with a small inclination can for example result in more stable substrate handling or a reduced risk of particles contaminating a deposited layer.

[0068] As exemplarily indicated in FIG. 9, the processing system can include a processing chamber 510, a processing device 520, and a carrier 100 according to any embodiments described herein. In particular, the processing chamber 510 may be a vacuum processing chamber, such as a deposition chamber adapted for a vacuum deposition process. For instance, the deposition process can be a PVD or CVD process. For example, the carrier 100 with the substrate 101 positioned thereon is provided in processing chamber 510 for substrate processing. In particular, the carrier 100 can be configured according to embodiments described herein and can have one or more holders 200 as described herein. Further, as exemplarily shown in FIG. 9, the processing system 500 may include a transportation device 540 configured for transporting a carrier 100 according to embodiments described herein. [0069] According to embodiments, which can be combined with other embodiments described herein, the processing device 520 may be a deposition material source which can be provided in the processing chamber 510 facing the side of the substrate 101 to be processed, e.g. coated. As exemplarily indicated in FIG. 9, the deposition material source can provide deposition material 535 to be deposited on the substrate 101. For instance, the deposition material source can be a target with deposition material thereon or any other arrangement allowing material to be released for deposition on the substrate. In some implementations, the deposition material source can be a rotatable target. According to some embodiments described herein, the deposition material source can be movable in order to position and/or replace the deposition material source. According to other embodiments described herein, the deposition material source can be a planar target.

[0070] According to some embodiments described herein, which can be combined with other embodiments described herein, the deposition material 535 can be chosen according to the deposition process and the later application of the coated substrate. For instance, the deposition material 535 of the deposition material source can be a material selected from the group consisting of: 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 deposition material source or by reactive deposition, i.e. the material from the deposition material source can react with elements like oxygen, nitride, or carbon from a processing gas.

[0071] 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.

[0072] In particular, this written description uses examples to disclose the disclosure, including the best mode, and also to enable any person skilled in the art to practice the described subject-matter, including making and using any devices or systems and performing any incorporated methods. While various specific embodiments have been disclosed in the foregoing, mutually non-exclusive features of the embodiments described above may be combined with each other. The patentable scope is defined by the claims, and other examples are intended to be within the scope of the claims if the claims have structural elements that do not differ from the literal language of the claims, or if the claims include equivalent structural elements with insubstantial differences from the literal language of the claims.