Method of depositing a material layer and deposition system

Abstract

A method of depositing a material layer on a substrate in a vacuum processing system is described. The method includes depositing a first portion of the material layer at a first deposition power to increase a temperature of the substrate to a first temperature; and depositing a second portion of the material layer at a second deposition power lower than the first deposition power, the second deposition power being configured to cause the substrate to be at about the first temperature or below until a final layer thickness of the material layer being reached.

Description

METHOD OF DEPOSITING A MATERIAL LAYER AND DEPOSITION SYSTEMTECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to material deposition on a substrate, particularly a large area substrate. For example, material can be sputtered on the substrate. Further, embodiments of the present disclosure relate to temperature control of a substrate, for example, a large area substrate on an electrostatic chuck (ESC). Embodiments relate to a method of depositing a material layer. Specifically, embodiments relate to methods of depositing a material layer on a substrate in a vacuum processing system and a deposition system for depositing a material layer on a substrate in a vacuum chamber.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, including substrates for high-density displays. Some applications include insulating panels, substrates with TFTs, 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 all deposited on a substrate.

[0003] In order to process a substrate in a processing system, substrates are transported through subsequent processing chambers of the processing system, such as deposition chambers and optionally further processing chambers, e.g., cleaning chambers and / or etching chambers, wherein processing aspects are subsequently conducted in the processing chambers such that a plurality of substrates can be subsequently processing in a cluster system or continuously or quasi-continuously be processed in the in-line processing system. A substrate maybe supported on a support such as a support table or the substrates can be loaded onto substrate supports that are transported through the processing system.

[0004] Substrates supported by a substrate support table or transported by a carrier to be processed in a vacuum processing system may include one or more layers of previously deposited materials. A substrate including a previously processed layer is to be referred to as a substrate for the upcoming processing. A layer that is provided 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. For example, a PVD process can be a PVD sputtering process.

[0005] Further, substrate processing is beneficially conducted at a high deposition rate to reduce the tact time of the processing. Accordingly, temperature limits on the one hand and high deposition rates on the other hand provide conflicting interests.

[0006] In light of the above, an improvement of a method of depositing a layer, particularly with a reduced substrate temperature, at a similar average deposition rate, is beneficially provided.SUMMARY

[0007] In light of the above, methods of depositing a material layer on a substrate in a vacuum processing system and deposition systems for depositing a material layer on a substrate in a vacuum chamber 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.

[0008] According to an embodiment, a method of depositing a material layer on a substrate in a vacuum processing system is provided. The method includes depositing a first portion of the material layer at a first deposition power to increase a temperature of the substrate to a first temperature; and depositing a second portion of the material layer at a second deposition power lower than the firstdeposition power, the second deposition power being configured to cause the substrate to be at about the first temperature or below until a final layer thickness of the material layer being reached.

[0009] According to an embodiment, a method of depositing a material layer on a substrate in a vacuum processing system is provided. The method includes determining an average deposition rate to provide a predetermined layer thickness in a predetermined deposition time; depositing a first portion of the material layer a first deposition rate higher than the average deposition rate until the substrate reached a first temperature; and depositing a second portion of the material layer at a second deposition rate lower than the first deposition rate, the second deposition rate being configured to cause the substrate to be at about the first temperature or below until the predetermined layer thickness being reached.

[0010] According to an embodiment, a deposition system for depositing a material layer on a substrate in a vacuum chamber is provided. The deposition system includes a substrate support having a substrate support body with a front side within the vacuum chamber; one or more deposition sources provided in the vacuum chamber configured to provide a deposition zone for a substrate supported on the substrate support; one or more power supplies connected to the one or more deposition sources; and a controller comprising: a processor and a memory storing instructions that, when executed by the processor, cause performing a method according to any of the embodiments described herein.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] 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 cross-sectional view of a substrate support, utilized in or for embodiments described herein;FIG. 2A shows graphs illustrating a correlation between deposition power, layer thickness, and substrate temperature for a common deposition process;FIG. 2B shows graphs illustrating a correlation between deposition power, layer thickness, and substrate temperature for a method according to some embodiments of the present disclosure and, in comparison, to FIG. 2A;FIG. 2C shows further graphs illustrating a correlation between deposition power, layer thickness, and substrate temperature for a method according to some further embodiments of the present disclosure and, in comparison, to FIG. 2A;FIG. 3A shows a schematic view of a processing system for processing a substrate according to embodiments described herein;FIG. 3B shows a schematic view of a processing apparatus for processing a substrate according to embodiments described herein;FIG. 3C shows a schematic view of a processing system for processing a substrate according to embodiments described herein;FIG. 4 shows a flow chart of a method of depositing a material layer on a substrate in a vacuum processing system, and deposition systems for depositing a material layer on a substrate in a vacuum chamber, according to embodiments described herein; andFIG. 5 shows a flow chart of a further method of depositing a material layer on a substrate in a vacuum processing system, and deposition systems for depositing a material layer on a substrate in a vacuum chamber, according to embodiments described herein.DETAILED DESCRIPTION OF EMBODIMENTS

[0012] 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.

[0013] A deposition process, such as a PVD sputter process, transfers energy to a substrate. The substrate will heat up during deposition, e.g. sputtering, due to the transferred energy. For PVD sputtering, a common recipe to create a desired layer thickness is to use a constant sputter power and, thus, a constant deposition rate for the entire process time. A constant deposition power or constant sputter power according to embodiments of the present disclosure may also be understood as a deposition power that is oscillating with a plurality of cycles (e.g. 10 or more) during the entire process time such that average deposition power is constant, i.e. the deposition power averaged over one oscillation. Further, the substrate temperature may not exceed certain limits for some processes.

[0014] Embodiments of the present disclosure provide methods of depositing a material layer, with different deposition powers or different deposition rates (i.e. different average deposition powers or different average deposition rates) to reducethe substrate temperature for a deposition process or to delimit the substrate temperature below a threshold, while increasing the overall deposition rate. According to embodiments of the present disclosure, during a first or early phase of the deposition time the substrate is heated up, i.e. faster than average. For example, the substrate is heated up as fast as possible up to a predetermined temperature. For example, the predetermined temperature can be a maximum allowed temperature for the process.

[0015] According to some embodiments, which can be combined with other embodiments of the present disclosure, during the first or early phase of the depositing of the material layer, the layer can be deposited with a maximum, or close to maximum (e.g. 80 % of maximum or more) deposition power. As compared to a constant process, the layer thickness will grow faster. In a second phase after the first or early phase, the deposition power, e.g. the sputter power, is lowered. The deposition power is lowered such that the incoming process energy is in equilibrium or lower than the outgoing energy. The substrate temperature is constant or decreasing. During the second phase, the energy loss of the substrate, i.e. the cooling, is increased or maximized because the temperature difference between the substrate and the surrounding of the substrate, such as a cooling gas or a substrate support table, is increased or maximized. Further, the higher substrate temperature at an early stage of the layer deposition process also increases the radiation heat loss of the substrate.

[0016] According to an embodiment, a method of depositing a material layer on a substrate in a vacuum processing system is provided. The method includes depositing a first portion of the material layer at a first deposition power to increase the temperature of the substrate to a first temperature; depositing a second portion of the material layer at a second deposition power lower than the first deposition power, the second deposition power being configured to cause the substrate to be at about the first temperature or below, until a final layer thickness of the material layer is reached.

[0017] During deposition of a material layer, a substrate, such as a large area substrate may be supported on a substrate support, e.g. a substrate support table.FIG. 1 shows a schematic cross-sectional view of a substrate support. Substrate supports can be used in a processing system, such as a vacuum deposition system, for holding and / or transporting substrates within a vacuum chamber of the processing system. As an example, one or more material layers can be deposited on the substrate while the substrate is supported by 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 processing chamber of a vacuum processing system. A support table may particularly be configured for horizontal substrate processing or essentially horizontal substrate processing. For example, the processing chamber, including the substrate support, may be provided in a cluster system.

[0018] According to some embodiments of the present disclosure, which can be combined with other embodiments described herein, a substrate support can be a carrier, particularly a carrier within 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 a vacuum processing system and can support the substrate during processing of the substrate.

[0019] A substrate may be held or supported by a substrate support at a rear side i.e. the side of the substrate which does not face the deposition source. The front side of the substrate is the side of the substrate facing the deposition source. In some applications, substrate supports may include electrostatic chucks for holding the substrate at a rear side. When loading the substrate onto the substrate support, the substrate may be provided onto the electrostatic chuck until electrostatic forces are sufficiently established. According to some embodiments, which can be combined with other embodiments described herein, a substrate support can be an electrostatic chuck with integrated substrate cooling.

[0020] FIG. 1 shows a schematic cross-sectional view of a substrate support 100 according to embodiments described herein. The substrate support may be a substrate support table. The substrate support 100 is configured for supporting asubstrate in a processing chamber, particularly a vacuum processing chamber. The substrate support 100 includes a substrate support body 140 having a substrate support surface, for example, a front side 142, for supporting the substrate. Opposite the front side 142, a back side 143 is provided. Further, the substrate support includes a chuck assembly. The chuck assembly is configured to hold the substrate at the substrate support surface. The chuck assembly may include an electrode assembly 125 for providing electrostatic forces to the substrate. For example, an electrostatic field may be provided by the electrode assembly 125, particularly a plurality of electrodes 122 to act on the substrate for holding the substrate.

[0021] According to embodiments described herein, the substrate support 100 includes a substrate support surface, i.e. the front side 142. According to embodiments, the substrate support may include a plurality of channels 116 in the substrate support surface. The plurality of channels 116 may be connected to the gas conduit 110. The gas conduit may be connected to a gas supply. The gas conduit may be connected to a gas source 160 for providing a cooling gas. For example, the gas source 160 can be a gas tank or a gas supply of a processing system. The gas conduit may include a plurality of channels 116. Each of the channels of the plurality of channels 116 may open into one opening of a plurality of first openings, i.e. an opening in the substrate support surface.

[0022] By providing a cooling gas, for example helium into the gas conduit or channels 116, the cooling gas can be provided between the substrate 10 supported by the substrate support 100 and the substrate. As shown in FIG. 1 , one or more seals 141 can be provided between the substrate 10 and the front side 142. A gas cushion can be provided at the rear side of the substrate 10.

[0023] Accordingly, the substrate temperature can be reduced during substrate processing. According to some embodiments, which can be combined with other embodiments described herein, the cooling gas can be selected from the group consisting of: helium, argon or the like.

[0024] According to embodiments described herein, the substrate support may include at least one non-conductive area. The at least one non-conductive area maybe made of a dielectric material. Particularly, the dielectric may be made of a high thermal conductivity dielectric material, such as pyrolytic boron nitride, aluminum nitride, aluminum oxide, silicon nitride, alumina or an equivalent material, but may be made of such materials as polyimide. The electrode assembly 125 may be embedded in the at least one non-conductive area or provided on the side of the non-conductive area, opposite the substrate support surface.

[0025] According to some embodiments, which can be combined with other embodiments described herein, the substrate support 100 may include one or more voltage sources configured to apply one or more voltages to the plurality of electrodes 122. In some implementations, the one or more voltage sources are configured to ground at least some electrodes of the plurality of electrodes 122. As an example, the one or more voltage sources 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 122. 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 source. The term “polarity” refers to an electric polarity, i.e., negative (-) and positive (+). As an example, the first polarity can be the negative polarity and the second polarity can be the positive polarity, or the first polarity can be the positive polarity and the second polarity can be the negative polarity. According to some embodiments, which can be combined with other embodiments described here, the ESC of the substrate support can be a mono-polar or a bi-polar electrostatic chuck.

[0026] According to embodiments, a controller 130 can be configured to control the one or more voltage sources for applying the one or more voltages and / or ground to the electrode assembly 125. The controller 130 may be configured to regulate the chuck assembly i.e. the controller may be configured to control the electrostatic chucking. The controller 130 may be configured to regulate the gas source 160. According to yet further embodiments, which can be combined with other embodiments described herein, the controller can be configured to control or communicate with a temperature. According to yet further embodiments, which can be combined with other embodiments described herein, the controller 130 asillustrated in FIG. 1 may be separated into individual controllers for the voltage source, the gas supply, and / or the temperature sensors.

[0027] As exemplarily shown in FIG. 1 , a temperature sensor 155, such as an temperature sensor can be provided. The temperature sensor can be provided in the substrate support body. Utilization of a temperature sensor, e.g. at or in the substrate support 100 or external to the substrate support, particularly for measuring a substrate temperature will be described in more detail below.

[0028] As used throughout the present disclosure, “substantially horizontal” is understood particularly when referring to the substrate orientation, to allow for a deviation from the horizontal direction or orientation of ±20° or below, e.g. of ±10° or below. As used throughout the present disclosure, “substantially vertical” is understood particularly 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 from a vertical orientation 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 a facing down substrate orientation might even better reduce particles on the substrate during deposition. Yet, the substrate orientation, e.g., during a layer deposition process, is considered substantially vertical. Generally, horizontal and vertical substrate orientations can be differentiated, wherein both orientations, a horizontal orientation or a vertical orientation may include a deviation as described above.

[0029] A substrate 10 supported on a substrate support 100, e.g. a substrate support table, as shown in FIG. 1 , can be cooled by various heat transfer mechanism. In vacuum applications, such as deposition processes in vacuum chambers according to the present disclosure, a loss of heat energy via radiation can be dominant, whereas thermal conduction in vacuum is low. An ESC provides improved contact of a rear side of the substrate and a front side of e.g. a substrate support body. Accordingly, conductance can be increased. Further, a cooling gas at the rear side of the substrate can provide convection to result in loss of heat energy of the substrate.

[0030] Generally, additional cooling of the substrate might be implemented with sophisticated means and costly equipment might be implemented for processes where the substrate temperature needs to stay low during a sputter process, i.e. a deposition process in general. For example, additional chillers, utilization of compressed dry air, etc. may be utilized to provide a cooling of e.g. below 0°C. Embodiments of the present disclosure allow to reduce the technical effort of cooling, and thus, the costs of equipment, since any of the above-mentioned cooling mechanism provides increased heat transfer, the larger the temperature difference between the substrate and the cooling feature, or the larger the substrate temperature, as such. Conductance and convection increases linearly with the temperature difference of the substrate relative to the substrate support body and the cooling gas, respectively. Radiation increases with the temperature raised to the power of four according to Stefan-Boltzmann-law.

[0031] FIG. 2A shows some graphs obtainable during a layer deposition on a substrate. Embodiments of the present disclosure are provided to deposition in general, even though examples are provided with respect to sputter deposition.

[0032] FIG. 2A shows a temperature graph 22 over time, wherein the temperature is shown on the ordinate on the left-hand side over the abscissa t. The temperature results from the sputter power as shown in power graph 20. Further, a thickness graph 21 shows the layer thickness. The sputter power and the layer thickness are given as relative values on the ordinate on the right-hand side. In FIG. 2A, 100% sputter power relates to the sputter power for a constant deposition rate to arrive at the desired layer thickness, i.e. a thickness of 100%, within the time interval between t0and t-|. In other words, for the graphs illustrated in FIG. 2A, a sputter power of 100% is switched in at t0and is switched off at t-i after the final layer thickness of 100% has been reached. During deposition with the parameters in FIG. 2A, the temperature increases from a starting value, e.g. room temperature, to a value Tmax. After the sputter power is switched off at t-i , the temperature reduces. The value Tmaxcan be a maximum temperature that is allowed before a layer on the substrate deteriorates or can be a maximum temperature that is pre-set for the process, i.e. atemperature with a safety margin below a temperature before a layer on the substrate deteriorates or another limitation is reached.

[0033] As shown in FIG. 2B, according to embodiments of the present disclosure, the substrate is heated up faster as in FIG. 2A, e.g. as fast as possible to a maximum allowable temperature T’maxat a first phase (to to t’) of the sputtering time (to to t1 ). The temperature graph 220 is shown in FIG. 2B. For example, the sputter power (graph 200) can be at a relative value of about 200%. During this first phase with e.g. maximum achievable power, the layer thickness (graph 210) will also grow fast. According to embodiments of the present disclosure, a first portion of a material layer is deposited at a higher deposition rate as compared to a second portion of the material layer.

[0034] A second phase (t’ to t1 ) starts, for example, as soon as the maximum allowable substrate temperature T’maxhas been reached or the temperature is close to T’max. At time t1 , the sputter power is lowered significantly, e.g. to around 50% in FIG. 2B, such that the incoming energy from the process is in equilibrium with the energy dissipated via cooling. During the second phase, the cooling power is increased as compared to FIG. 2A, because of the temperature difference or because the temperature is increased, e.g. is maximum for the process. As shown in FIG. 2B, the maximum temperature T’maxin FIG. 2B is lower as compared to the maximum temperature Tmaxin FIG. 2A, e.g. by the difference 250 shown in FIG. 2B.

[0035] Accordingly, as shown in FIG. 2B, changing the sputter power during the process, and particularly during different phases of depositing a layer, can be provided to control the substrate temperature for a desired layer thickness (e.g. 100% in FIGS. 2A to 2C). Depending on the available maximum power, the temperature can be reduced by e.g. 3°C or more, particularly 5°C or more, such as by about 5°C to about 10°C. This may relate to a relative temperature reduction of approximately 10 % to 20 % for some processes. In other words, switching from maximum power in a first phase and to a lower level in a second phase can help to reduce substrate temperature, i.e. a maximum substrate temperature of a process, while keeping the process time constant. Additionally or alternatively, the throughput can be increased, e.g. at the temperature Tmax(FIG. 2A) or temperature betweenTmaxand T’max. Yet further, additionally or alternatively, embodiments can assist to save cost and complexity on equipment for cooling.

[0036] According to an embodiment, a method of depositing a material layer on a substrate in a vacuum processing system is provided. The method includes depositing a first portion of the material layer at a first deposition power to increase the temperature of the substrate to a first temperature; depositing a second portion of the material layer at a second deposition power lower than the first deposition power, the second deposition power being configured to cause the substrate to be at about the first temperature or below, until a final layer thickness of the material layer is being reached.

[0037] FIG. 4 shows a flow chart of illustrating methods of depositing a material layer according to embodiments of the present disclosure. At operation 410, a first portion of the material layer is deposited at a first deposition power. The temperature of the substrate is increased to a first temperature, e.g. a target temperature or a maximum temperature. As compared to a common approach as illustrated in FIG. 2A, the temperature increase is faster. At operation 420, a second portion of the material layer is deposited at a second deposition power lower than the first deposition power. The second deposition power can be adjusted to avoid a further substrate temperature increase and / or to cause the substrate to be at about the first temperature or below until a final layer thickness of the material layer being reached. For example, if the first power is maximized, the temperature of the substrate and / or the substrate temperature difference compared to a substrate support body and / or cooling fluid is maximized over time under the boundary condition of a maximum allowable substrate temperature for the deposition process.

[0038] According to some embodiments, which can be combined with other embodiments described herein, the first deposition power and the second deposition power can be applied to a sputter deposition source. The deposition process can be a sputter process, e.g. with rotatable cylindrical sputter targets.

[0039] As shown in FIG. 4, at operation 430, the substrate can be loaded on a support body with a chuck assembly, and at least a portion of the substrate can becooled with a cooling gas at operation 440. According to some embodiments, which can be combined with other embodiments described herein, a method of depositing a material layer, e.g., in a vacuum chamber, may further include loading the substrate on a substrate support having a substrate support body with a front side and a chuck assembly; and cooling at least a portion of the substrate loaded on the substrate support with a cooling gas. For example, the cooling can include flowing the cooling gas through a plurality of first openings in the front side of a substrate support body of the substrate support.

[0040] As described with respect to FIG. 2B, the deposition process at a reduced substrate temperature can be provided within the same process time, e.g. between t0and t-i. According to some embodiments, which can be combined with other embodiments described herein, the method may further include determining a reference deposition time for reaching the final layer thickness at a constant deposition power; and adjusting the first deposition power and the second deposition power to reach the final layer thickness within the reference deposition time. For example, the first deposition power can be higher, i.e. significantly higher, such as at least 140% of the constant deposition power, as compared to the constant deposition power and the second deposition power can be lower as compared to the constant deposition power, i.e. significantly lower, such as at most 70% of the constant deposition power.

[0041] FIG. 5 shows another flow chart of a method of depositing a material layer on a substrate in a vacuum processing system. The method is similar to the method of FIG. 4 and the aspects, features and details described with respect to FIG. 4 may similarly apply to the method illustrated in FIG. 5. Yet, the method of FIG 5 provides an alternative by adjusting and / or controlling deposition rates. The method includes at operation 510 determining an average deposition rate to provide a predetermined layer thickness in a predetermined deposition time. At operation 520, the method includes depositing a first portion of the material layer at a first deposition rate higher than the average deposition rate until the substrate reached a first temperature. At operation 530, the method includes depositing a second portion of the material layer at a second deposition rate lower than the first deposition rate, the seconddeposition rate being configured to cause the substrate to be at about the first temperature or below until the predetermined layer thickness is being reached.

[0042] According to some embodiments, which can be combined with other embodiments described herein, the method may further include defining a constant deposition power for the average deposition rate; and adjusting the first deposition rate and the second deposition rate to reach the predetermined layer thickness within the predetermined deposition time.

[0043] For the methods described with respect to FIGS. 2B and 2C and FIGS. 4 and 5, a first higher deposition power and a second lower deposition power is provided. In the event of other oscillating modifications of the deposition power, this may relate to a first higher average deposition power and a second lower average deposition power. Particularly, the first deposition power or first average deposition power is applied at a first or early phase of the layer deposition and the second deposition power or second average deposition is applied at a second phase after the first or early phase. For example, the second phase can be directly after the first or early phase, and / or until the final layer thickness is reached.

[0044] According to some embodiments, which can be combined with other embodiments described herein, the first deposition power can be 130% or more of the constant deposition power and / or the second deposition power is 70% or less of the constant deposition power.

[0045] As described above, a further power variation of a sputter power may also be provided. For example, for a static deposition process, a magnetron in a rotatable sputter cathode may have a varying angular position. For, example, the magnetron may wobble or oscillate to provide a more uniform layer thickness distribution. In such cases or other cases, the sputter power may vary as a function of the angular position of the magnetron. Further oscillating power variations can exist. The first sputter power and the second sputter power according to embodiments described herein are different as described herein when averaged over one or more potentially existing oscillations. According to some embodiments, which can be combined with other embodiments described herein, at least one of the first deposition power andthe second deposition power may oscillate dependent on a magnetron angular position. The second deposition power, lower than the first deposition power may, thus, relate to a second average deposition power, lower than a first average deposition power and / or a second deposition power averaged over one or more oscillating cycles being lower than a first deposition power averaged over one or more oscillating cycles.

[0046] As described above, in addition to and / or alternatively to considering a reduced substrate temperature, a consideration of embodiments of the present disclosure can also reduce equipment costs, particularly for cooling equipment utilized for substrate cooling. Accordingly, a substrate temperature may also be increased.

[0047] According to various embodiments of the present disclosure the temperature reduction by power control according to embodiments described herein, can be utilized such that the equipment for substrate cooling can be reduced. For example, a gas cushion can be avoided, i.e. no cooling gas can be provided between the substrate support and the substrate. Additionally or alternatively an electrostatic chuck can be avoided. For example, a deposition system may be simplified to include a substrate support, wherein the substrate support body is a cooled plate without an electrostatic chuck to generate a force on the substrate and / or without channels for a cooling gas generating a gas cushion. Further additionally or alternatively, the substrate support temperature can be increased to temperatures allowing cooling fluids, such as water or the like, to be used. In other words cooling fluid such as glycol or galden fluids may also be avoided.

[0048] According to some embodiments, which can be combined with other embodiments described herein, a substrate support temperature can be -5 °C or more, such as 5°C or more. For example, the substrate support temperature might even be 10°C or more during deposition.

[0049] Some embodiments of the present disclosure relate inter alia to processes with a boundary condition to keep the substrate temperature low. For example, for PVD-coating on top of sensitive layers (e.g. OLED layers), limiting the substratetemperature to e.g. < 80°C or «80°C is beneficial to avoid damage of OLED layers. Utilization of e.g. an electrostatic chuck, a gas cushion with cooling gas and / or cold substrate support, which can act as a heat sink for the substrate, e.g. a glass substrate, are beneficial. For such solutions or for other solutions, e.g. with reduced equipment costs, an adjustment of the power, i.e. utilization of a high “cooling power” improves the heat transfer, particularly the hotter the substrate temperature in average. It is beneficial, to heat up the glass, e.g. as fast as possible, to a temperature limit in a first phase or an early phase of the deposition process. Switching the power from a first (maximum) level in a first phase and a second, lower level in a second phase a) can help to reduce the max. temperature while keeping the process time constant b) can increase the throughput, and / or c) can help to save cost and complexity on equipment (PVD-sputter, OLED, power-supply, temperature control equipment).

[0050] For some applications, such as touchscreen panels (TSP) including organic layers, the substrate having the organic layer may be sensitive to temperature increases during subsequence substrate processing operations, such as sputtering of further layers on the substrate. A cooling gas, for example, helium can be provided into a gap between the substrate, for example, a glass substrate, and the electrostatic chuck. According to some embodiments, which can be combined with other embodiments described herein, the substrate temperature is provided to be at 100°C or below, particularly 80°C or below. According to some embodiments, which can be combined with other embodiments described herein, a gas cushion, for example, a helium cushion with for example about 3 to 10 mbar can be provided. The heat transfer between the substrate and the plate of the ESC, for example a water-cooled plate, can be improved.

[0051] According to some embodiments, which can be combined with other embodiments described herein, the material layer can be deposited over an organic material.

[0052] FIG. 2C shows graphs similar to FIGS. 2A and 2B and illustrates yet further embodiments of the present disclosure. Sputtering can be associated with a bombardment of the substrate, or particularly a film located on the substrate, withenergetic particles. The bombardment may have a disadvantageous influence on the properties of a material, particularly a film, located on the substrate. To avoid the bombardment, facing target sputtering (FTS) systems were devised, for example, with planar targets or particularly also with rotatable targets. For example, for rotatable targets, magnetrons in neighboring rotatable targets may essentially face each other. In an FTS system, instead of facing the substrate directly, the targets face each other. Advanced FTS systems can include rotary targets to increase material utilization. Thus, in addition to being sensitive to temperature, layers may also be sensitive to bombardment with energetic particles as such. Accordingly, according to some embodiments, which can be combined with other embodiments described herein, facing target sputtering with rotary (cylindrical) targets can be provided. For example, a FTS method may include directing first sputter material from a first rotary target with a facing magnet yoke position towards a second rotary target with a first power supply during a first power cycle; directing second sputter material from a third rotary target with a facing magnet yoke position towards the second rotary target with a second power supply during the first power cycle; and directing third sputter material from the second rotary target with a facing magnet yoke position towards the first rotary target; and, optionally, directing fourth sputter material from the second rotary target with a facing magnet yoke position towards the third rotary target. For example, a method may further, optionally include switching the first power supply and the second power supply from the first power cycle to a second power cycle.

[0053] For improving the reduction of damage to a layers additionally or alternatively a seed layer may be deposited. The temperature graph 222 is shown in FIG. 2C. As shown in FIG. 2C, according to some embodiments of the present disclosure, an initial deposition phase before the early or first phase can be provided. The initial deposition phase can be from t* to t0. Thereafter, the first or early phase t0to t’ is provided. During the initial phase a seed layer is deposited. According to some embodiments, which can be combined with other embodiments described herein, during the initial phase the sputter power (graph 202) can be lower than the first sputter power. Additionally the sputter power during the initial phasecan be lower than a constant sputter power (compared to e.g. FIG. 2A) or even the second sputter power (compared to the second phase in FIG. 2B).

[0054] Thereafter, in the first or early phase, the substrate is heated up faster as in FIG. 2A, e.g. as fast as possible to a maximum allowable temperature T’maxat a first phase (t0to t’) of the sputtering time (t* to h). The other details explained, e.g. with respect to FIGS. 2B and 4 or 5, may also be provided for the embodiments described with respect to FIG. 3C. The thickness graph 212 is shown in FIG. 2C.

[0055] According to some embodiments, which can be combined with other embodiments described herein, a method may further include depositing a seed layer at a seed layer deposition power before depositing the first portion of the material layer at the first deposition power, wherein the seed layer deposition power is lower than at least one of the first deposition power and the second deposition power.

[0056] As illustrated with respect to FIGS. 3A to 3C, embodiments of the present disclosure also relate to deposition systems, and particularly deposition systems including a controller comprising: a processor and a memory storing instructions that, when executed by the processor, cause performing a method according to any of the embodiments described herein.

[0057] According to one embodiment, a deposition system for depositing a material layer on a substrate in a vacuum chamber is provided. The deposition system includes a substrate support having a substrate support body with a front side and a chuck assembly within the vacuum chamber and one or more gas conduits in fluid communication with a plurality of first openings in the front side of the substrate support body configured to cool at least a portion of the substrate loaded on the substrate support with a cooling gas. Further, one or more deposition sources are provided in the vacuum chamber configured to provide a deposition zone for a substrate supported on the substrate support, and one or more power supplies connected to the one or more deposition sources. The deposition system further includes a controller comprising: a processor and a memory storing instructions that, when executed by the processor, cause performing a method according to any ofthe embodiments of the present disclosure. For example, the one or more deposition sources can be one or more rotatable sputter sources.

[0058] FIG. 3A shows a substrate processing system 300. The substrate processing system 300 can be a cluster system having a transfer chamber 320. The transfer chamber 320 can be a central transfer chamber. A robot 322 can at least be partially disposed within the transfer chamber 320. The robot 322 can have a robot arm 354. The robot 322 can transfer substrates between the chambers coupled to the transfer chamber 320. At least one load lock chamber 305 can be coupled to the transfer chamber 320. FIG. 3A shows two load lock chambers 305 coupled to the transfer chamber 320. One or more deposition systems 310 can be coupled to the transfer chamber 320. The robot 322 can transfer the substrate between a load lock chamber and a deposition chamber and vice versa or between different deposition chambers attached to the transfer chamber 320.

[0059] A deposition system 310 includes a vacuum chamber. Further, the transfer chamber 320 can be a vacuum transfer chamber. Accordingly, a substrate can be handled under vacuum from the load lock chamber to the transfer chamber, from the transfer chamber to the vacuum chamber of a deposition apparatus and from vacuum chamber of first deposition apparatus to a vacuum chamber to a further deposition apparatus.

[0060] The apparatuses and systems described herein are configured in order to move and process large area substrates that may in particular have a surface of 1 m2 or above. The term “substrate” may particularly embrace substrates like glass substrates, for example, a glass plate. Further, a substrate may include wafers, slices of transparent crystal such as sapphire or the like. However, the term “substrate” may embrace other substrates that can be inflexible or flexible, like e.g. a foil or a web. The substrate may be formed by any material suitable for material deposition.

[0061] FIG. 3A schematically shows a substrate processing system 300 including one or more deposition systems 310 according to the present disclosure. The one or more deposition systems 310 are intended for the deposition of material on asubstrate, and include a vacuum chamber and / or a sputter source area according to embodiments of the present disclosure. An array of deposition sources configured to deposit material on the substrate at a processing area in a horizontal orientation can be provided. The substrate processing system 300 further includes a transfer chamber 320, particularly a vacuum transfer chamber coupled to the one or more deposition apparatuses.

[0062] FIG. 3A further shows load lock chambers 305. The vacuum transfer chamber 320 is coupled to the one or more deposition systems. The vacuum transfer chamber can move substrates to the one or more vacuum chambers through openings, particularly horizontal slit openings. The load lock chambers 305 are configured to receive a substrate under atmospheric pressure are not under vacuum conditions A and then to transfer the substrate into the vacuum transfer chamber under vacuum conditions V. Vice versa, the load chamber may also receive a substrate from the transfer chamber under a vacuum condition V and provide said substrate under atmospheric pressure or not under vacuum conditions A.

[0063] According to yet further embodiments, one or more further processing chambers may be coupled to the vacuum transfer chamber, for example, a central transfer chamber. Specifically, the one or more further processing chambers may be selected from a heating chamber coupled to the transfer chamber, a cooling chamber coupled to the transfer chamber, a pre-cleaning chamber coupled to the transfer chamber, a storage chamber coupled to the transfer chamber, an examination chamber coupled to the transfer chamber, and a CVD chamber coupled to the transfer chamber. One or more of the above chambers, of the same type and / or of a different type may be coupled to a central transfer chamber. The examination chamber may, for example, measure the thickness of a layer deposited in a previous deposition process, or may control one or more layer thicknesses before the substrate is unloaded from a processing system. A control of layer thickness can be provided. The cleaning or precleaning chamber may remove oxides from, for example, metal layers, or may remove photoresist residuals from a previous manufacturing step.

[0064] FIG. 3B shows a deposition system. The deposition system includes a vacuum chamber 311. According to embodiments of the present disclosure, the vacuum chamber 311 can include various segments. The segments can be defined by the functionality of the segments, i.e. some segments or portion of the segment and an adjacent segment may be fixedly connected or integrally formed. Separating the vacuum chamber into segments allows for reduced cost of ownership.

[0065] The vacuum chamber 311 as exemplarily shown in FIG. 3B includes a source frame segment 312. The source frame segment can be a fixed segment that is at a fixed position relative to the processing system, for example, relative to the central transfer chamber. The source frame segment is configured to support the source assembly and / or a source support assembly, respectively. As shown in FIG. 3B, a plurality of sputter cathode 351 and a plurality of anodes 352 are provided in the source frame segment. Alternatively, another source, such as an evaporation source, a spraying source, or a CVD source may be coupled to the source frame segment.

[0066] An upper lid assembly is provided over the source frame segment 312. The upper lid assembly 314 can be removed from the source frame segment, for example, for maintaining components disposed in the upper lid assembly and / or for maintaining components of the source assembly or the source support assembly.

[0067] A substrate handling segment 316 is provided below the source frame segment. The substrate handling segment 316 includes or houses components for substrate handling, substrate alignment, substrate masking, substrate support, or the like. Particularly, the substrate support 100 can be a substrate support table and can be provided according to any of the embodiments of the present disclosure.

[0068] FIG. 3B shows the substrate support 100 and the actuator 333 coupled to the substrate support 100. The actuator 333 can be a linear actuator or drive configured to move the substrate support 100 vertically. For example, FIG. 3B shows the substrate support 100 in a first position below the upper ends of the substrate support pins or lift pins 282. The actuator 333 may move the substrate support 100, to a second position, i.e. an upper position, wherein the substratesupport is positioned above the upper ends of substrate support pins. The substrate disposed on the substrate support pins 282 will be contacted by the substrate support upon movement of the substrate support from the first position to the second position. Accordingly, the substrate can be disposed on the substrate support for material deposition by lifting the substrate support from the first position to the second position. Further, the substrate can be disposed on the substrate support pins or lift pins 282, for example, after deposition, by lowering the substrate support holding the substrate from the second position to the first position.

[0069] The substrate support 100 acts as a table to support the substrate during deposition of a material layer on the substrate. If the table is moved to the upper position, i.e. the second position, the substrate can be disposed below the edge exclusion mask 330. The substrate support shown in FIG. 3B is a substrate support according to embodiments of the present disclosure. The substrate support may include an electrostatic chuck.

[0070] FIG. 3C exemplarily shows a schematic view of a processing system 300 for processing a substrate according to embodiments described herein. Particularly, the processing system may be a deposition system. The processing system includes a loading station 372, a vacuum processing chamber 390, and a load lock chamber 380 between the loading station and the vacuum processing chamber. The loading station is configured for horizontal loading of the substrate, e.g. with a lift pin array, on a carrier according to embodiments described herein. The loading station 372 may be an atmospheric chamber 370 i.e. a chamber where atmospheric pressure is provided. The processing system may further include one or more transfer chambers 382.

[0071] Processing of a substrate may be understood as transferring material to a substrate, etching a substrate, pre-treatment of a substrate, heating the substrate, e.g. during annealing, or another substrate processing. For example, deposition material may be deposited on the substrate, for example, by a CVD process or a PVD process, such as sputtering or evaporation. The substrate 10 may include a deposition material receiving side. The deposition material receiving side of the substrate may be regarded as the side of the substrate facing a deposition source.Further, processing of a substrate may also include transportation of the substrate from one chamber to another chamber of the processing system.

[0072] According to embodiments, the processing system 300 as shown in FIGS 3A to 3C may be configured for CVD or PVD processes, such as sputter deposition. For example, the processing system may be a processing system for large area substrates, e.g., for display manufacturing. Specifically, the processing systems for which the structures and methods according to embodiments described herein are provided, are 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.

[0073] According to embodiments described herein, the processing system i.e. the vacuum processing chamber may include one or more material deposition sources 392. The one or more material deposition sources may be sources for sputter deposition or evaporation of one or more materials on a substrate.

[0074] According to some embodiments, which can be combined with other embodiments described herein, the one or more material deposition sources 392 can be controlled by a controller 350. Particularly, a sputtering power or another power relating to a deposition rate of a material deposition source may be adjusted by the controller 350 according to embodiments of the present disclosure. The controller 350 can further be connected to a temperature sensor at a carrier supporting the processed substrate and / or a temperature sensor of a carrier supporting the processed substrate.

[0075] According to embodiments, the substrate processing system may include a transport system 385. The transport system may be configured to transport one or more carriers. The one or more carriers may be configured for transporting one ormore substrates 10. Particularly, the transport system 385 may include transportation paths extending through the processing system. The one or more carriers may be transported through the processing system with or without having loaded one of the one or more substrates 10. The transport system may include a magnetic levitation transport system and / or a mechanical transport system.

[0076] According to embodiments that can be combined with any other embodiments described herein, the processing system may include a carrier including a chuck assembly.

[0077] According to some embodiments, which can be combined with other embodiments described herein, a vacuum processing system or a deposition system may include a controller 350 as exemplarily shown in FIG. 3C. The controller 350 can be connected to one or more deposition sources, and particular one or more power supplies of the one or more deposition sources. The controller may also be connected to one or more temperature sensors of the substrate support. The controller 350 comprises a central processing unit (CPU), a memory and, for example, support circuits. To facilitate control of the substrate processing, the CPU may be one of any form of general-purpose computer processor that can be used in an industrial setting for controlling various chambers and sub-processors. The memory is coupled to the CPU. The memory, or a computer readable medium, may be one or more readily available memory devices such as random-access memory, read only memory, hard disk, or any other form of digital storage either local or remote. The support circuits may be coupled to the CPU for supporting the processor in a conventional manner. These circuits include cache, power supplies, clock circuits, input / output circuitry and related subsystems, and the like. Substrate processing instructions, and particular deposition power instructions during a first phase and a second phase, can be generally stored in the memory as a software routine typically known as a recipe. The software routine may also be stored and / or executed by a second CPU (not shown) that is remotely located from the hardware being controlled by the CPU. The software routine, when executed by the CPU, transforms the general-purpose computer into a specific purpose computer (controller) that controls the substrate processing, e.g. the deposition power toreduce the substrate temperature according to embodiments of the present disclosure. Although the method and / or process of the present disclosure is discussed as being implemented as a software routine, some of the method steps that are disclosed therein may be performed in hardware as well as by the software controller. As such, the invention may be implemented in software as executed upon a computer system, and in hardware as an application specific integrated circuit or other type of hardware implementation, or a combination of software and hardware. The controller may execute or perform the method of depositing a material layer on a substrate according to embodiments of the present disclosure.

[0078] 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.

[0079] 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.

Claims

CLAIMS1 . A method of depositing a material layer on a substrate in a vacuum processing system, the method comprising: depositing a first portion of the material layer at a first deposition power to increase a temperature of the substrate to a first temperature; and depositing a second portion of the material layer at a second deposition power lower than the first deposition power, the second deposition power being configured to cause the substrate to be at about the first temperature or below until a final layer thickness of the material layer being reached.

2. The method of claim 1 , wherein the first deposition power and the second deposition power are applied to a sputter deposition source.

3. The method of any of claims 1 to 2, further comprising: loading the substrate on a substrate support having a substrate support body with a chuck assembly; and cooling at least a portion of the substrate loaded on the substrate support with a cooling gas.

4. The method of claim 3, wherein the cooling comprises: flowing the cooling gas through a plurality of first openings in a front side of the substrate support body of the substrate support.

5. The method of any of claims 1 to 4, further comprising: determining a reference deposition time for reaching the final layer thickness at a constant deposition power; and adjusting the first deposition power and the second deposition power to reach the final layer thickness within the reference deposition time.

6. The method of claim 5, wherein the first deposition power is higher than the constant deposition power and the second deposition power is lower than the constant deposition power.

7. A method of depositing a material layer on a substrate in a vacuum processing system, the method comprising: determining an average deposition rate to provide a predetermined layer thickness in a predetermined deposition time; depositing a first portion of the material layer a first deposition rate higher than the average deposition rate until the substrate reached a first temperature; and depositing a second portion of the material layer at a second deposition rate lower than the first deposition rate, the second deposition rate being configured to cause the substrate to be at about the first temperature or below until the predetermined layer thickness being reached.

8. The method of claim 7, wherein for the first deposition rate a first deposition power and for the second deposition rate a second deposition power are applied to a sputter deposition source.

9. The method of claim 8, further comprising: defining a constant deposition power for the average deposition rate; and adjusting the first deposition rate and the second deposition rate to reach the predetermined layer thickness within the predetermined deposition time.

10. The method of any of claims 5 to 6, or 9, wherein the first deposition power is 130% or more of the constant deposition power.11 . The method of any of claims 5, or 9 to 10, wherein the second deposition power is 70% or less of the constant deposition power.

12. The method of any of claims 1 to 6 or 8 to 11 , wherein at least one of the first deposition power and the second deposition power is oscillating dependent on a magnetron angular position.

13. The method of any of claims 1 to 12, wherein a substrate support temperature is 10°C or more during deposition.

14. The method of any of claims 1 to 13, wherein the material layer is deposited over an organic material.

15. The method of any of claim 1 to 14, further comprising:depositing a seed layer at a seed layer deposition power before depositing the first portion of the material layer at the first deposition power, wherein the seed layer deposition power is lower than at least one of the first deposition power and the second deposition power.

16. A deposition system for depositing a material layer on a substrate in a vacuum chamber, comprising: a substrate support having a substrate support body with a front side within the vacuum chamber; one or more deposition sources provided in the vacuum chamber configured to provide a deposition zone for a substrate supported on the substrate support; one or more power supplies connected to the one or more deposition sources; and a controller comprising: a processor and a memory storing instructions that, when executed by the processor, cause performing a method according to any of claims 1 to 15.

17. The deposition system of claim 16, wherein the substrate support further includes a chuck assembly.

18. The deposition system of any of claims 16 to 17; further comprising: one or more gas conduits in fluid communication with a plurality of first openings in the front side of the substrate support body configured to cool at least a portion of the substrate loaded on the substrate support with a cooling gas.

19. The deposition system of any of claims 16 to 18, wherein the one or more deposition sources are one or more rotatable sputter sources.

20. The deposition system of any of claims 16 to 19, wherein the substrate support body is a cooled plate.

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