WO2022237975A1

WO2022237975A1 - Method of substrate checking, and substrate processing system

Info

Publication number: WO2022237975A1
Application number: PCT/EP2021/062616
Authority: WO
Inventors: Bernhard Stock; Simon Lau; Roland Weber
Original assignee: Applied Materials, Inc.
Priority date: 2021-05-12
Filing date: 2021-05-12
Publication date: 2022-11-17
Also published as: CN117256044A

Abstract

A method of substrate checking is described. The method includes placing a substrate (10) on a substrate support (120) in a vacuum processing chamber (101); introducing a gas (20) through the substrate support into a region (150) between the substrate support and the substrate via a gas supply (130); and measuring an actual pressure in the gas supply (130) or the region (150) for determining a substrate defect or an incorrect substrate placement on the substrate support. Further, a substrate processing system (100) is described that is configured for the substrate checking method described herein.

Description

METHOD OF SUBSTRATE CHECKING, AND SUBSTRATE PROCESSING SYSTEM

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to a method of checking the state of a substrate, for example for detecting a substrate defect, such as a substrate breakage. Specifically, methods described herein relate to the processing of substrates, such as large- area glass substrates, in a vacuum processing chamber, and specifically to the determination of a substrate defect before, during and/or after the deposition of a material on the substrate. Embodiments described herein further relate to a substrate processing system for processing a substrate in a vacuum chamber, including inspecting the substrate for a potential defect.

BACKGROUND

[0002] Techniques for layer deposition on a substrate include, for example, physical vapor deposition (PVD), chemical vapor deposition (CVD), and thermal evaporation. Coated substrates may be used in several applications and in several technical fields. For instance, substrates for displays can be coated by a PVD process, such as sputtering, or by thermal evaporation. Some applications relate to insulating panels, substrates with TFTs, displays, color filters or the like. A coated substrate, such as a substrate for a display, may include one or more layers of a material situated between two electrodes that are deposited on the substrate.

[0003] In order to process a substrate in a processing system, the substrate may be transported through vacuum processing chambers of a substrate processing system, such as a vacuum deposition chamber and optionally further processing chambers, e.g., cleaning chambers and/or etching chambers, wherein processing aspects are subsequently conducted. A plurality of substrates can be subsequently processed in a cluster system, or can be processed continuously or quasi-continuously in an in-line processing system. A substrate

1 may be supported on a substrate support such as a support table during the processing, and/or a substrate can be loaded on a substrate support (also referred to herein as a substrate carrier) that can be transported through the substrate processing system. Accordingly, substrate supports can be stationary or movable through the substrate processing system.

[0004] Substrates to be processed in a substrate processing system may include one or more layers of previously deposited materials. A material that is deposited on the substrate may be temperature sensitive. Particularly organic materials that have previously been deposited on the substrate can be damaged by temperatures of, for example, 60°C or above, 80°C or above, or 100°C or above. Therefore, it may be beneficial to cool the substrate during further processing, in order to avoid damage to a sensitive substrate layer during the further processing.

[0005] One relevant issue in the processing of substrates is the determination of substrate defects, such as cracks, holes or breakage, in order to avoid the processing of defective substrates and in order to improve the quality of the coated substrates. Further, the coating of a surface of the substrate support through a hole or crack of the substrate is to be avoided. Typically, substrates are inspected optically, e.g., with a camera, in order to optically determine whether the substrate is broken. However, an optical inspection of substrates is not always reliable.

[0006] In light of the above, an improved method of checking a substrate, particularly a large-area glass substrate, would be beneficial. Further, a substrate processing system configured to reliably check a substrate to be processed for detecting potential defects would be beneficial.

SUMMARY

[0007] In light of the above, methods of substrate checking and substrate processing systems according to the independent claims are provided. Further features, aspects, details, and implementations are described in the detailed specification, the drawings, and the dependent claims.

2 [0008] According to one aspect, a method of substrate checking is provided. The method includes placing a substrate on a substrate support in a vacuum processing chamber, introducing a gas through the substrate support into a region between the substrate support and the substrate via a gas supply, and measuring an actual pressure in the gas supply or the region for determining a substrate defect or an incorrect substrate placement on the substrate support.

[0009] Specifically, a pressure variation or pressure deviation in the region may be determined by measuring the actual pressure in the gas supply. For example, the actual pressure may be compared with a predetermined pressure value, and a substrate defect or an incorrect substrate placement may be assumed, if a difference between the actual pressure and the predetermined pressure value exceeds a threshold. Alternatively or additionally, the actual pressure may be monitored for determining a pressure variation or a pressure deviation indicative of a substrate defect or an incorrect substrate placement.

[0010] The gas may optionally be a cooling gas configured to cool the substrate during the processing in the vacuum processing chamber.

[0011] According to one aspect, a substrate processing system is provided. The substrate processing system includes a vacuum processing chamber, a substrate support in the vacuum processing chamber with a substrate support surface for placing a substrate thereon, a gas supply for introducing a gas through the substrate support into a region between the substrate support and the substrate, a pressure gauge for measuring an actual pressure in at least one of the gas supply and the region, and a controller configured to determine a substrate defect or an incorrect substrate placement on the substrate support based on the actual pressure.

[0012] The substrate processing system may be configured to conduct a substrate inspection according to any of the methods described herein. Specifically, the controller may comprise a processor and a memory storing instruction that, when executed on the processor, cause performing a substrate checking method according to any of the embodiments described herein.

[0013] The present disclosure is to be understood as encompassing apparatuses and systems for carrying out the disclosed methods, including apparatus parts for performing

3 each described method aspect. Method aspects may be performed for example by hardware components, by a computer programmed by appropriate software or by any combination of the two. The present disclosure is also to be understood as encompassing methods for operating described apparatuses and systems. Methods for operating the described apparatuses and systems include method aspects for carrying out every function of the respective apparatus or system. The present disclosure is to be understood as encompassing products, specifically processed substrates, manufactured according to any of the described methods. In particular, coated substrates manufactured according to any of the methods described herein and/or using any of the substrate processing systems described herein are provided.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] So that the manner in which the above recited features of the present disclosure 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 view of a substrate processing system according to embodiments described herein;

FIGS. 2 A and 2B show schematic views of a substrate processing system configured to inspect a substrate according to any of the methods described herein;

FIG. 3 shows a schematic view of a substrate processing system according to embodiments described herein; and

FIG. 4 shows a flow chart of a method of substrate checking according to embodiments described herein.

4 DETAILED DESCRIPTION OF EMBODIMENTS

[0015] 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. 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 of the disclosure. 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.

[0016] Substrate supports can be used in a substrate processing system, such as a vacuum deposition system, for holding and/or transporting substrates within a vacuum processing chamber of the substrate processing system. As an example, one or more material layers can be deposited on the substrate while the substrate is supported on a substrate support surface of the substrate support. According to some embodiments of the present disclosure, which can be combined with other embodiments described herein, a substrate support can be a support table, e.g. a substrate support table, or a pedestal, e.g. a substrate support pedestal, provided in a vacuum processing chamber of a substrate processing system. A support table may particularly be configured for horizontal substrate processing or essentially horizontal substrate processing. For example, the vacuum processing chamber including the substrate support may be provided in a cluster system. Alternatively, the substrate support table may be configured for processing the substrate in an essentially vertical orientation.

[0017] According to some embodiments of the present disclosure, which can be combined with other embodiments described herein, the substrate support can be a substrate carrier, particularly a carrier within a chuck assembly, such as an electrostatic chuck (ESC). The carrier may particularly be configured for vertical substrate processing or essentially vertical substrate processing. The substrate can be supported by the carrier and the carrier can move the substrate through the substrate processing system and can support the substrate during processing of the substrate.

[0018] FIG. 1 shows a substrate processing system 100 according to embodiments described herein. The substrate processing system 100 is configured for a method of

5 checking a substrate 10 as described herein. The substrate processing system 100 includes a vacuum processing chamber 101 that can be evacuated and a substrate support 120 that is arranged in the vacuum processing chamber 101 and is configured for supporting the substrate 10. Specifically, the substrate support 120 may include a substrate support surface 121 for placing the substrate 10 thereon.

[0019] The substrate 10 may be placed on the substrate support surface 121 of the substrate support 120 for being processed in the vacuum processing chamber 101, e.g., for being coated with a material. The substrate support 120 may be a stationary substrate support table or may be a substrate carrier that is movable into and out of the vacuum processing chamber.

[0020] For some applications, such as touchscreen panels (TSP) including organic layers, the substrate 10 may include a thin glass plate, e.g., a glass plate with a thickness of 1 mm or less, particularly 0.7 mm or less. The substrate may be a large-area substrate having a main surface with a surface area of 1 m² or more, particularly 3 m² or more. Optionally, the substrate may have one or more material layers or material patterns, e.g., including an organic material deposited on a glass plate. In some applications, the substrate processing system may be a semiconductor processing system, and the substrate may be or include a semiconductor substrate, such as a wafer.

[0021] The substrate may be susceptible to cracks, breakage, holes or other defects, e.g. if the substrate includes a thin glass plate. It is beneficial to inspect the substrate before, during and/or after processing in order to find out if the substrate has a defect, such as a hole or crack, or is broken. Further, it is beneficial to inspect the substrate before, during and/or after the processing for finding out in case the substrate is not correctly placed on the substrate support. Typically, substrates are inspected optically, e.g. with a camera, in order to check whether the substrate has a defect and is correctly positioned. However, an optical substrate inspection is not always reliable, for example because a camera is not able to inspect the whole surface area of a large-area substrate.

[0022] According to embodiments described herein, the substrate 10 placed on the substrate support 120 is checked/inspected as follows. A gas 20 is introduced through the substrate support 120 into a region between the substrate support 120 and the substrate 10 via a gas supply 130. An actual pressure in the gas supply 130 and/or in the region 150

6 between the substrate support 120 and the substrate 10 is measured for determining a substrate defect or an incorrect substrate placement on the substrate support 120. Specifically, a pressure variation or pressure deviation from a predetermined pressure value in the region 150 is determined by measuring the actual pressure in the gas supply 130.

[0023] As is depicted in FIG. 1, the substrate processing system 100 includes a gas supply 130 for introducing the gas 20 through the substrate support 120 into the region 150 between the substrate support 120 and the substrate 10. Further, a pressure gauge 135 is provided for measuring the actual pressure in the gas supply 130 and/or in the region 150. The pressure gauge 135 may be connected to a controller 136 configured to determine a substrate defect or an incorrect substrate placement on the substrate support 120 based on the measured actual pressure.

[0024] The determination of a substrate defect or an incorrect substrate placement can be conducted as follows. The actual pressure may be monitored for determining a pressure variation or a pressure deviation from a predetermined pressure value that is indicative of a substrate defect or an incorrect substrate placement. Alternatively or additionally, the measured actual pressure may be compared with a predetermined pressure value, and a substrate defect or an incorrect substrate placement may be assumed if a difference between the actual pressure and the predetermined pressure value exceeds a threshold.

[0025] As is schematically depicted in FIG. 1, the substrate 10 is placed on the substrate support surface 121 of the substrate support 120, such that a (typically small) region is formed between the substrate support surface 121 and the substrate 10. For example, the substrate support surface 121 may have a surface roughness, such that the substrate that is placed on the substrate support surface 121 is not everywhere in direct contact with the substrate support surface 121, and variable small spaces (e.g., with distances between the substrate support surface 121 and the substrate 10 on a sub- 100 micron scale) that form the region 150 are formed between the substrate support surface 121 and the substrate 10 (see FIG. 2B in this respect). For example, the region 150 may have an (average) thickness in a direction perpendicular to the substrate of 1 mm or less, particularly 0.5 mm or less. In some embodiments, one or more recesses or depressions may be formed in the substrate support surface 121, such that the substrate 10 is not in contact with portions of the substrate support surface 121 where the one or more recesses are arranged. The gas 20 can be introduced into

7 said region 150 that is formed between the substrate support 120 and the substrate 10 through the substrate support, as is schematically depicted in FIG. 1.

[0026] A main volume 102 of the vacuum processing chamber 101 may be evacuated during the substrate processing, e.g. to a sub-atmospheric pressure of less than 1 mbar, particularly lxl0²mbar or less, more particularly lxl0³mbar or less. Since the gas 20 is introduced into the region 150 between the substrate support 120 and the substrate 10, the pressure in said region 150 (which may be, e.g., 1 mbar or more, or 5 mbar or more and/or 50 mbar or less) may be higher than the pressure in the main volume 102 of the vacuum processing chamber 101, such that the gas escapes from the region 150 into the main volume 102 of the vacuum chamber through gaps between the substrate support and the substrate.

[0027] In some embodiments, the substrate 10 is attracted to the substrate support 120 with a chuck assembly, e.g., with an electrostatic chuck 140, a magnetic chuck, or another chuck such a mechanical chuck. By attracting the substrate 10 to the substrate support 120, a lifting or fly-off of the substrate 10 from the substrate support 120 caused by the overpressure in the region 150 relative to the main volume 102 of the vacuum processing chamber 101 can be avoided. Specifically, by attracting the substrate 10 to the substrate support surface 121 of the substrate support 120 with the chuck assembly, the substrate 10 can be held reliably at the substrate support 120 at a predetermined position in the vacuum processing chamber 101, e.g. in an aligned position relative to a deposition source. A slippage of the substrate can be avoided and it can be ensured that the substrate remains at a predetermined position on the substrate support 120 during the processing.

[0028] In some embodiments, the chuck assembly is an electrostatic chuck 140. The electrostatic chuck 140 may include a plurality of electrodes that may be provided in a body 125 of the substrate support 120, for example in a top plate of the substrate support 120. For example, the plurality of electrodes may be integrated in a top plate of the substrate support 120 at a position close to the substrate support surface 121. In particular, a distance between the electrodes of the electrostatic chuck 140 and the substrate support surface 121 may be 1 cm or less, particularly 0.1 cm or less, in some embodiments. In implementations, one or more voltage supplies 141 may be provided to apply one or more voltages to the plurality of electrodes of the electrostatic chuck 140.

8 [0029] As an example, the one or more voltage supplies 141 can be configured to apply a first voltage having a first polarity, a second voltage having a second polarity, and/or ground to the plurality of electrodes. According to some embodiments, each electrode, every second electrode, every third electrode or every fourth electrode of the plurality of electrodes can be connected to a separate voltage. For example, the electrodes may be alternately connected to a positive and to a negative voltage, as is schematically depicted in FIG. 1 (“bi-polar chuck”). The term “polarity” refers to an electric polarity, i.e., negative (-) and positive (+). According to some embodiments, which can be combined with other embodiments described here, the electrostatic chuck of the substrate support can be a mono-polar or a bi-polar electrostatic chuck (ESC). A mono-polar or a bi-polar ESC may be used in a substrate support for supporting a horizontally oriented substrate. A bi-polar ESC may be used in a substrate support for supporting a vertically oriented substrate. According to embodiments, a chuck controller can be configured to control the one or more voltage supplies for applying the one or more voltages and/or ground to the electrodes. The chuck controller may be configured to control the chuck assembly, i.e. the chuck controller may be configured to control the electrostatic chucking.

[0030] In some embodiments, the substrate 10 is checked as follows: First, the substrate is placed on the substrate support 120 in the evacuated vacuum processing chamber 101. The substrate 10 is then attracted to the substrate support 120 by activating the attractive force of the chuck assembly. Thereupon, the gas 20 is introduced into the region 150 via the gas supply 130, e.g. with a predetermined flow rate, particularly with a fixed gas flow rate. If the substrate 10 is correctly placed on the substrate support 120 and has no defect (e.g., no crack and no breakage), a predetermined pressure establishes in the region 150 and in the gas supply 130, and the predetermined pressure remains essentially constant. The actual pressure in the region or in the gas supply is measured with the pressure gauge 135. Based on the measured actual pressure, it can be determined if the substrate is broken or is incorrectly placed on the substrate support.

[0031] For example, if a difference between the actual pressure measured by the pressure gauge 135 and a predetermined pressure value exceeds a threshold, it can be assumed that the substrate has a defect or is not correctly placed on the substrate support. Specifically, if the substrate has a breakage, a hole or a crack, the gas can quickly escape from the region

9 150 into the main volume 102 of the vacuum processing chamber through the defect, such that the measured actual pressure will be considerably lower than the predetermined pressure value. If the substrate is incorrectly placed on the substrate holder, the gas can quickly escape from the region 150 since the substrate does not correctly cover and hence “close” the region 150, such that the measured actual pressure will be considerably lower than the predetermined pressure value. Accordingly, an actual pressure that is lower than the predetermined pressure value can be considered indicative of a substrate defect or an incorrect substrate placement. According to the substrate checking method described herein, it can be quickly and reliably determined even for large-area substrates if the substrate has a defect or is not correctly placed on the substrate support, accelerating the substrate processing and reducing the number of defective substrates.

[0032] In some embodiments, which can be combined with other embodiments described herein, a state of the substrate is monitored by monitoring the actual pressure continuously or at predetermined time intervals, e.g. before, during and/or after the processing of the substrate. In some embodiments, the state of the substrate is monitored by comparing the actual pressure continuously or at predetermined time intervals with a predetermined pressure value. If a pronounced pressure variation or a pressure deviation from the predetermined pressure value is determined, a substrate defect or misplacement may be assumed. For example, an alarm or an indication on a display can be triggered in this event, or an optical substrate inspection process can be triggered for verifying whether the substrate is defective or not correctly placed on the substrate support. In some embodiments, if it is determined that the substrate is not correctly placed on the substrate support, a substrate re alignment process may be conducted, e.g. automatically or manually. If it is verified that the substrate is defective, e.g. optically, the substrate can be removed from the vacuum processing system. Other appropriate measures can be taken.

[0033] In some embodiments, which can be combined with other embodiments described herein, a peripheral edge of the substrate is supported on edge support sections 122 (also referred to as a “dam”) of the substrate support 120, and the gas 20 leaves the region 150 and enters the evacuated main volume of the vacuum processing chamber 101 at the edge support sections 122, if the substrate has no defect and is correctly positioned. The flow path of the gas that leaves the region 150 is schematically depicted by arrows 65 in FIG. 1.

10 Specifically, due to the overpressure of the gas in the region 150 as compared to the main volume 102, the gas streams through small gaps between the edge support section 122 and the peripheral edge of the substrate also if the substrate is attracted toward the substrate support by the chuck assembly.

[0034] The gas supply 130 may include a gas supply line 132 in fluid communication with a plurality of gas distribution channels 131 that extend through a body 125 of the substrate support, each gas distribution channel including an outlet for releasing the gas into the region 150 between the substrate support and the substrate. In some embodiments, the gas may be released into the region 150 through ten or more gas distribution channels, particularly through fifty or more gas distribution channels, more particularly hundred or more gas distribution channels, or even hundreds. For example, if the substrate support 120 has a substrate support surface 121 configured to support a large-area substrate, ten or more gas distribution channels that are spaced apart from each other in the plane of the substrate support surface may release the gas into the region 150. The plurality of gas distribution channels 131 may ensure a quick and uniform gas distribution into the region 150, facilitating the determination of potential substrate defects and optionally providing a more uniform and more efficient substrate cooling by the gas 20.

[0035] In some embodiments, the gas 20 is provided by a gas source 133, such as a noble gas source, is guided through a gas supply line 132 into the body 125 of the substrate support, and is distributed to different sections of the region 150 by the plurality of gas distribution channels 131 that extend through the body 125. The gas supply line 132 may be a gas tube that connects the gas source 133 with the plurality of gas distribution channels 131 in the interior of the substrate support 120.

[0036] In some embodiments, the substrate support 120 includes a bottom plate with grooves or recesses in a main surface thereof, the grooves or recesses in the bottom plate being covered by a cover plate of the substrate support 120 that is arranged on top of the bottom plate, such that gas distribution lines extending essentially parallel to the substrate support surface 121 are formed between the bottom plate and the cover plate. The plurality of gas distribution channels 131 may extend through the cover plate (and optionally through a top plate in which the chuck assembly is integrated) in a direction perpendicular to the substrate support surface 121, establishing fluid connections between the gas distribution

11 lines and the region 150. Such a multi-plate configuration of the substrate support 120 facilitates the manufacture of a network of gas distribution lines and channels extending through the body 125 of the substrate support 120, such that the gas 20 can be uniformly introduced into the region 150 below the substrate 10.

[0037] In some embodiments, the gas 20 is a cooling gas. The substrate 10 may be cooled with the gas during the processing, while the substrate 10 is supported on the substrate support 120. Specifically, the substrate 10 may be cooled by the gas 20 from below during a deposition of a material on a top surface of the substrate 10. A negative effect on the substrate by a (typically hot) deposition material may be reduced or avoided by cooling the substrate from below with the gas 20. For example, the gas 20 may be introduced into the region 150 via the gas supply 130 at a temperature of 30°C or less, e.g. at an ambient temperature, in order to avoid an excessive temperature rise of the substrate during the processing. For example, the temperature of the substrate can be maintained at 100°C or less, particularly at 80°C or less, more particularly at 60°C or less, if the substrate is cooled by the gas 20 during the processing.

[0038] According to embodiments described herein, the gas 20 can both be used for cooling and for inspecting the substrate, particularly for determining substrate defects. Due to the above double function of the gas 20, costs can be avoided and the complexity of the system can be reduced.

[0039] In some embodiments, the gas 20 is a noble gas and the gas source 133 is a noble gas source. For example, the gas 20 may include or be helium or argon. Argon is beneficially used for cooling the substrate because argon does not cause any chemical reactions, can be pumped well and is readily available.

[0040] In some implementations, the substrate support 120 is liquid-cooled. In particular, cooling lines for a liquid cooling medium may extend through the substrate support, particularly through a bottom plate of the substrate support. For example, a water-cooling circuit with cooling lines extending partially through the body 125 of the substrate support may be provided. Heat may be transported from the substrate 10 to the substrate support 120 by the gas 20, and the substrate support 120 may be cooled by the cooling lines 161 filled with a circulating liquid cooling medium, particularly water. Accordingly, the temperature

12 of the substrate can be kept low during the processing and the quality of the material deposited on the substrate can be improved.

[0041] In some embodiments, the vacuum processing chamber 101 is a vacuum deposition chamber that houses a deposition source configured to deposit a material on the substrate supported on the substrate support, particularly in an essentially horizontal orientation. The deposition source may for example be a sputter source. The deposition source may be arranged to face toward the top surface of the substrate that is supported on the substrate support.

[0042] The substrate 10 may be or include a thin glass plate, e.g., a glass plate with a thickness of 1 mm or less, particularly 0.7 mm or less. The glass plate may have a surface area of 1 m² or more, particularly 3 m² or more, in some implementations.

[0043] FIG. 2A and FIG. 2B show schematic views of a substrate processing system 200 according to embodiments described herein. The substrate processing system 200 may include some features or all of the features of the substrate processing system 100 of FIG. 1, such that reference can be made to the above explanations, which are not repeated here. The vacuum processing chamber which houses the substrate support 120 is not depicted in FIGS. 2 A and 2B.

[0044] The substrate processing system 200 includes the substrate support 120 arranged in a vacuum processing chamber. The substrate support 120 includes a substrate support surface 121 for placing the substrate 10 thereon. A gas supply 130 for cooling the substrate that is placed on the substrate support surface 121 is provided, the gas supply 130 including a gas supply line 132 in fluid communication with a plurality of gas distribution channels 131 extending through the body 125 of the substrate support. The gas distribution channels have outlets provided in the substrate support surface 121 for releasing a gas 20 from below toward the substrate 10 that is placed on the substrate support surface 121. Ten or more gas distribution channels may be provided in some embodiments.

[0045] Optionally, a substrate lifting system with a plurality of lift pins 171 that are movable relative to the substrate support 120 may be provided. The lift pins may extend through openings of the substrate support during the relative movement, i.e., during lifting

13 or lowering of the substrate relative to the substrate support. The substrate 10 can be placed on the lift pins 171 and can be lowered on the substrate support surface 121 by moving the lift pins 171 in a downward direction through the substrate support, until the substrate is placed on the substrate support. Alternatively, the substrate can be placed on the lift pins, whereupon the substrate support is moved up with respect to the stationary lift pins toward the substrate, until the substrate is in contact with and supported on the substrate support.

[0046] For removing the substrate from the substrate support, the substrate can be lifted from the substrate support surface 121 by moving the lift pins 171 through the substrate support 120 in an upward direction. Alternatively, the substrate support can be lowered with respect to stationary lift pins on which the substrate is supported, until the substrate is positioned on the lift pins at a distance above the substrate support.

[0047] As is schematically depicted in FIG. 2A and FIG. 2B, the substrate 10 can be placed on the substrate support surface 121 of the substrate support 120, e.g. by placing the substrate on the lift pins 171 that are provided in an extracted position (see FIG. 2A), and by moving the lift pins 171 downwardly, until the substrate is in contact with and supported on the substrate support surface 121 (see FIG. 2B).

[0048] When the substrate 10 is placed on the substrate support surface 121, a chuck assembly may be activated for chucking the substrate toward the substrate support surface 121. In particular, an electrostatic chuck 140 may be switched on by applying respective voltages to a plurality of electrodes that may be integrated in the substrate support 120 with one or more voltage supplies 141.

[0049] When the substrate 10 is attracted to the substrate support surface 121, a gas 20 may be introduced through the substrate support 120 into the region 150 between the substrate support 120 and the substrate 10 via the gas supply 130.

[0050] The gas 20 may have the purpose of cooling the substrate, e.g. during processing, particularly during material deposition on the substrate, and/or the gas 20 may have the purpose of checking the substrate, e.g. for determining if the substrate is broken or otherwise defective or is incorrectly placed on the substrate support 120. The substrate can be checked by measuring and/or monitoring an actual pressure in the gas supply 130 with a pressure

14 gauge 135 that may be connected to the gas supply line 132 of the gas supply 130. Since the gas supply line 132 is in fluid communication with the region 150 via the plurality of gas distribution channels 131, the pressure in the gas supply line 132 depends on the pressure in the region 150, and a pressure variation in the region 150 leads to a corresponding pressure variation in the gas supply line 132.

[0051] For example, if the substrate includes a crack 31 or another hole defect, the pressure in the region 150 will be affected because the gas 20 can quickly escape from the region 150 into the main volume of the vacuum processing chamber through the crack 31. Accordingly, the crack 31 leads to a pressure drop or to an unexpectedly low pressure in the gas supply line 132 that can be measured by the pressure gauge 135. Accordingly, by monitoring and/or measuring the actual pressure in the region 150, a hole defect of the substrate, particularly a breakage, can be detected.

[0052] If the substrate 10 is incorrectly placed on the substrate support 120, the gas 20 can quickly escape from the region 150 because the region is not properly covered and “closed” by the substrate 10. This is schematically depicted by reference numeral 32 in FIG. 2B. Accordingly, the misplacement or misalignment of the substrate leads to a pressure drop or to an unexpectedly low pressure in the gas supply line 132 that is measured by the pressure gauge 135. Accordingly, by monitoring and/or measuring the actual pressure in the region 150, an incorrect substrate placement can be detected.

[0053] In some embodiments, the substrate support surface 121 may have edge support sections 122 that circumferentially surround a central section of the substrate support surface 121, the surface roughness of the central section being higher than the surface roughness of the edge support sections 122. Accordingly, if peripheral edges of the substrate are placed on the edge support sections 122 which are flat, the region 150 is formed between the rough central section of the substrate support surface and the substrate, and the region 150 is covered and substantially “closed” by the substrate being in circumferential contact with the edge support sections 122. If the substrate is not defective and properly placed on the substrate support surface 121, the gas can slowly and uniformly escape from the region 150 at the edge support sections 122 and an essentially constant pressure is established in the region, particularly if a constant gas flow is provided through the gas supply line 132 into the region 150. On the other hand, if the substrate is defective or improperly placed, the

15 region 150 is in direct fluid communication with the main volume of the vacuum processing chamber, resulting in a pressure drop in the region that can be measured with pressure gauge 135. Accordingly, a substrate breakage or a substrate misplacement can be reliably determined according to the substrate checking methods described herein.

[0054] In some embodiments, the substrate support 120 may include cooling lines 161 for a liquid cooling medium, particularly water-cooling lines, extending through the substrate support 120. Accordingly, the substrate 10 can be cooled with the gas 20, and in addition the substrate support 120 may be liquid-cooled in order to further reduce the substrate temperature and in order to dissipate the heat from the substrate support. The quality of the layers deposited on the substrate can be improved and negative effects on sensitive substrate layers by excessive heat can be reduced.

[0055] In some embodiments, a controller 136 may be provided that is configured to determine substrate defects and/or incorrect substrate placements based on the actual pressure measured by the pressure gauge 135. For example, the controller 136 may be configured to monitor the pressure for determining pressure variations and/or pressure deviations that may be indicative of a substrate defect and/or a substrate misplacement.

[0056] In some embodiments, the controller 136 comprises a processor and a memory storing instructions that, when executed by the processor, cause performing the method of substrate checking according to any of the embodiments described herein. In particular, the controller 136 may be configured to monitor a substrate state by monitoring the actual pressure in the gas supply 130 and/or the region 150 continuously or at predetermined time intervals, e.g., before, during and/or after the substrate processing.

[0057] FIG. 3 shows a schematic view of a substrate processing system 300 for processing a substrate according to embodiments described herein. The substrate processing system 300 may be a vacuum deposition system. The substrate processing system 300 may include a substrate loading station 372, a vacuum processing chamber 101, and a load lock chamber 380 between the substrate loading station 372 and the vacuum processing chamber 101. The substrate loading station may be configured for horizontal loading of a substrate 10, e.g. with a lift pin array, on a substrate carrier that may be a substrate support according to embodiments described herein. The substrate loading station 372 may be an atmospheric

16 chamber 370, i.e. a chamber where atmospheric pressure is provided. The substrate processing system 300 may further include one or more transfer chambers 382.

[0058] Processing of a substrate may include depositing material on a substrate, etching a substrate, pre-treatment of a substrate, heating the substrate, e.g. during annealing, and/or another substrate processing. For example, a coating material may be deposited on the substrate, e.g., by a CVD process or a PVD process, such as sputtering or evaporation. Processing of a substrate may also include transportation of the substrate from one chamber to another chamber of the vacuum processing system.

[0059] According to embodiments, the substrate processing system 300 as shown in FIG. 3 may be configured for CVD or PVD processes, such as sputter deposition. In another example, the system can be configured for evaporation of, e.g., an organic material for the manufacture of OLED devices. For example, the substrate processing system may be a system for processing large-area substrates, e.g., for display manufacturing. Specifically, the substrate processing systems for which the structures and methods according to embodiments described herein are provided, may be for processing large area substrates having, for example, an area of 1 m² or larger. For instance, a large-area substrate can be GEN 5, which corresponds to a surface area of about 1.4 m² (1.1 m x 1.3 m), GEN 7.5, which corresponds to a surface area of about 4.29 m² (1.95 m x 2.2 m), GEN 8.5, which corresponds to a surface area of about 5.7 m² (2.2 m x 2.5 m), or even GEN 10, which corresponds to a surface area of about 8.7 m² (2.85 m x 3.05 m). Even larger generations such as GEN 11 and GEN 12 and corresponding surface areas can similarly be implemented.

[0060] According to some embodiments, which can be combined with other embodiments described herein, the substrate processing system 300 is configured for applications, for example, for touchscreen panels (TSP).

[0061] According to some embodiments described herein, the substrate processing chamber may include one or more deposition sources 105. The one or more deposition sources 105 may be sources for sputter deposition or evaporation of one or more materials on the substrate. The one or more deposition sources 105 may be arranged in the vacuum processing chamber 101 and may be configured to deposit a material on the substrate that is supported on the substrate support 120. The substrate support 120 may be stationary in the

17 vacuum processing chamber 101 or may be movable through the one or more transfer chambers 382 into the vacuum processing chamber 101, particularly together with the substrate 10 supported thereon.

[0062] According to embodiments, the substrate processing system may process the substrate under vacuum conditions. Vacuum conditions as used herein include pressure conditions in the range of below 10 ¹ mbar, or below 10³ mbar. Vacuum conditions may be applied through the use of vacuum pumps or other vacuum creating techniques.

[0063] According to embodiments, the substrate processing system may include a substrate transport system 385. The substrate transport system 385 may be configured to transport one or more substrate supports. The one or more substrate supports may be configured for holding one or more substrates. In particular, the substrate transport system 385 may include transportation paths extending through the substrate processing system. The substrate transport system may include a magnetic levitation transport system and/or a mechanical transport system.

[0064] In other embodiments, the substrate processing system is a cluster system with several substrate processing chambers, e.g. arranged next to a transport chamber. The substrate can be moved into a substrate processing chamber from the transport chamber, e.g. in a horizontal orientation, and/or the processed substrate can be moved out of each substrate processing chamber back into the transport chamber, e.g. in a horizontal orientation.

[0065] According to some embodiments, which can be combined with any other embodiment described herein, a substrate support 120 as described herein may be provided in the vacuum processing chamber 101. The substrate 10 to be processed can be placed on the substrate support 120 and deposited with a coating material in the vacuum processing chamber 101.

[0066] The deposition source 105 may be configured for depositing the coating material on the substrate that is placed on the substrate support. The substrate may be placed on the substrate support in an essentially horizontal orientation during the material deposition (i.e., the orientation of the substrate may be horizontal +/- 10° during the deposition). Alternatively, the substrate may be placed on the substrate support in an essentially vertical

18 orientation during the material deposition (i.e., the orientation of the substrate may be vertical +/- 10° during the deposition).

[0067] The substrate can be checked before, during or after the processing according to any of the substrate checking methods described herein for determining if the substrate has a defect (particularly for detecting a substrate breakage or another hole defect) and/or is incorrectly placed on the substrate support. Particularly, a gas may be introduced into the region between the substrate support and the substrate, and an actual pressure in the region may be measured. Based on the measured actual pressure, a substrate breakage or an incorrect substrate placement can be detected. Optionally, during the processing of the substrate, the substrate can be cooled with the gas that is introduced into the region, such that the gas is both used for cooling and for substrate inspection.

[0068] FIG. 4 shows a flow chart of a method of substrate checking according to embodiments described herein.

[0069] In box 410, a substrate is placed on a substrate support surface of a substrate support in a vacuum processing chamber. For example, lift pins may be used for placing the substrate on the substrate support. For example, the substrate can be placed on the lift pins that extend through openings of the substrate support, and the substrate support can move upward with respect to the stationary lift pins until the substrate is in contact with and supported on the substrate support. Alternatively, the lift pins with the substrate supported thereon can move downwardly through openings in the substrate support until the substrate is in contact with and supported on the substrate support. In other words, the substrate support and the lift pins extending through openings in the substrate support may be movable relative to each other.

[0070] In optional box 420, the substrate is attracted toward the substrate support surface with a chuck assembly, particularly with an electrostatic chuck that may be integrated in the substrate support.

[0071] In box 430, a gas is introduced through the substrate support into the region between the substrate support and the substrate via a gas supply. In particular, the gas may be released into the region through outlets of a plurality of gas distribution channels that extend through

19 a body of the substrate support. Optionally, the gas may cool the substrate from below, e.g., during processing.

[0072] In box 440, an actual pressure in at least one of the gas supply and the region is measured. A controller determines if the substrate is defective or incorrectly placed on the substrate support based on the measured actual pressure. In particular, the actual pressure may be monitored for determining pressure variations and/or pressure deviations from a predetermined pressure value that are indicative of a substrate defect or an incorrect substrate placement.

[0073] If such a pressure variation or pressure deviation is detected, appropriate measures can be taken. For example, the substrate can be optically inspected for determining whether a defect or a misplacement are present, the substrate can be recognized as defective, and/or the substrate can be re-aligned and correctly placed on the substrate support.

[0074] While the foregoing is directed to embodiments, other and further embodiments may be devised without departing from the basic scope, and the scope is determined by the claims that follow.

[0075] 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.

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Claims

1. A method of substrate checking, comprising: placing a substrate (10) on a substrate support (120) in a vacuum processing chamber (101); introducing a gas (20) through the substrate support into a region (150) between the substrate support and the substrate via a gas supply (130); and measuring an actual pressure in the gas supply (130) or the region (150) for determining a substrate defect or an incorrect substrate placement on the substrate support.

2. The method of claim 1, further comprising at least one of monitoring the actual pressure for determining a pressure variation or pressure deviation indicative of a substrate defect or an incorrect substrate placement; and comparing the actual pressure with a predetermined pressure value and assuming a substrate defect or an incorrect substrate placement if a difference between the actual pressure and the predetermined pressure value exceeds a threshold.

3. The method of claim 1 or 2, wherein the gas (20) is released into the region (150) through outlets of a plurality of gas distribution channels (131) that extend through a body (125) of the substrate support and are in fluid communication with a gas supply line (132).

4. The method of any of claims 1 to 3, further comprising: attracting the substrate to the substrate support with a chuck assembly.

5. The method of claim 4, wherein the chuck assembly is an electrostatic chuck (140).

6. The method of any of claims 1 to 5, wherein the gas (20) is a cooling gas and wherein the substrate is cooled with the gas during processing.

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7. The method of any of claims 1 to 6, wherein the substrate support (120) is liquid- cooled, particularly wherein cooling lines (161) for a liquid cooling medium extend through the substrate support.

8. The method of any of claims 1 to 7, wherein a state of the substrate is monitored by monitoring the actual pressure and/or by comparing the actual pressure with a predetermined pressure value continuously or at predetermined time intervals.

9. The method of any of claims 1 to 8, wherein a peripheral edge of the substrate is supported on edge support sections (122) of the substrate support (120), and the gas (20) leaves the region and enters an evacuated main volume (102) of the vacuum processing chamber (101) at the edge support sections (122), if the substrate has no defect and is correctly placed on the substrate support.

10. The method of any of claims 1 to 9, wherein the vacuum processing chamber (101) is a vacuum deposition chamber that houses a deposition source (105), further comprising: depositing a coating material on the substrate that is placed on the substrate support.

11. The method of any of claims 1 to 10, wherein the substrate is or comprises a glass plate with a thickness of 0.7 mm or less.

12. The method of any of claims 1 to 11, wherein the substrate (10) is placed on the substrate support (120) via a plurality of lift pins (171) that are movable relative to the substrate support (120).

13. The method of any of claims 1 to 12, wherein the gas is a noble gas, particularly argon.

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14. A substrate processing system, comprising: a vacuum processing chamber (101); a substrate support (120) in the vacuum processing chamber with a substrate support surface (121) for placing a substrate (10) thereon; a gas supply (130) for introducing a gas (20) through the substrate support into a region (150) between the substrate support and the substrate; a pressure gauge (135) for measuring an actual pressure in the gas supply (130) or the region (150); and a controller (136) configured to determine a substrate defect or an incorrect substrate placement based on the actual pressure.

15. The substrate processing system of claim 14, wherein the controller (136) comprises a processor and a memory storing instructions that, when executed by the processor, cause performing the method of substrate checking of any of claims 1 to 13.

16. The substrate processing system of claim 14 or 15, wherein the gas supply (130) comprises a gas supply line (132) in fluid communication with a plurality of gas distribution channels (131) that extend through a body (125) of the substrate support (120), each gas distribution channel comprising an outlet for releasing the gas into the region (150) between the substrate support and the substrate, particularly ten or more gas distribution channels.

17. The substrate processing system of any of claims 14 to 16, wherein the substrate support (120) comprises an electrostatic chuck (140) for attracting the substrate to the substrate support surface (121).

18. The substrate processing system of any of claims 14 to 17, further comprising cooling lines (161) for a liquid cooling medium extending through the substrate support.

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19. The substrate processing system of any of claims 14 to 18, further comprising a substrate lifting system with a plurality of lift pins (171) that are movable relative to the substrate support (120).

20. The substrate processing system of any of claims 14 to 19, further comprising a deposition source (105) for depositing a material on the substrate placed on the substrate support (120), particularly in an essentially horizontal orientation.

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