WO2012101155A1

WO2012101155A1 - Methods and apparatuses for single sided wet processing

Info

Publication number: WO2012101155A1
Application number: PCT/EP2012/051107
Authority: WO
Inventors: Klaus Huber; Steve Huthwaite
Original assignee: Lotus Systems Gmbh
Priority date: 2011-01-25
Filing date: 2012-01-25
Publication date: 2012-08-02

Abstract

In a Method of single sided wet-processing of one or more substrates, comprising exposing only one side of the substrates to a liquid medium for processing, the substrates are used for forming one or more walls of a process chamber of a processing system.

Description

Methods and apparatuses for single sided wet processing

This invention relates to a wet process, and particularly to single-sided wet processing of substrates.

Background

Currently, wet coating processes are widely used in several industries, including semiconductor processing such as silicon device, glass processing and photovoltaic cell manufacturing, for the applications of surface preparation (such as cleaning or texturing) or thin film coatings (such as electroplating or electroless deposition). Rigid, semi-rigid, or even flexible substrates can be used, such as silicon wafers for device fabrication, glass substrates for display devices, silicon wafers, glass substrates or metallic sheets for solar eel! processing.

Conventional wet processing systems, such as thin film coating systems, typically include dipping or immersion o the substrates into the coating fluid. This conventional wet coating process results in a coating applied to both sides of the immersed substrates. In situations where the coating is required only on one side, it is then necessary to remove the coating from the other side with additional processing steps.

Prior art single-sided coating systems, such as U.S. 2009/031 1431, apply a coating fluid to one top side of a single horizontally oriented substrate. This approach has the drawback of requiring large footprint equipment to coat large substrates in high volumes as typically required in mass production applications.

Summary of the description

The present invention discloses apparatuses and methods for single sided wet processing of substrates, comprising exposing one side of the substrates to a liquid medium for processing, such as coating, cleaning, or etching. One advantage of single sided wet processing is the potential reduction of time and process steps, such as the elimination of cleaning or coating removal on the other side of the substrates. In an embodiment, the present invention discloses a system for processing only one side of the substrates, for example, by using the substrates to form one or more walls of the processing system. The process chamber forms a small processing volume, comprising a narrow channel for contacting the substrate surfaces, with the liquid entering at one side of the substrates and traveling along the substrate length. The narrow- channel of the processing system can allow reduced chemical consumpt ion, and thus can allow single use of chemical liquid, permitting high repeatability of wet processing. In addition, small processing volume can eliminate the need for recirculating the chemical, thus simplifying the process chamber mechanics.

In an embodiment, the substrates are oriented vertically (or near vertically) with chemical introduced at the bottom or at the top. Laminar flow can be achieved with improved liquid coverage, since any trapped bubbles would rise to the top surface. The speed of the chemical covering the substrates can be controlled through a pumping mechanism or through a flow controller. The vertical configuration of the process chamber can offer smaller footprint, which is important in semiconductor and solar cell fabrication facilities.

In an embodiment, the substrates are attached to the process chamber at both sides of the liquid channel, doubling the processing throughput with essentially similar chemical usage.

In an embodiment, the process chamber comprises removable walls with mating interfaces. The substrates can be the removable walls, affixed to the process chamber to be exposed to the chemical liquid in the process chamber, and removed from the process chamber when processing is complete. The substrates can be attached to the removable walls which are affixed to the process chamber during the wet process. The substrates are then removed from the removable walls to continue subsequent processing steps in the fabrication facility.

There can be a sealing mechanism between the removable walls or the substrates with the process chamber to contain the liquid chemicals. The seal mechanism can be a face seal or an edge seal, sealing the substrates to the process chamber. Alternatively, the sea! mechanism can seal the removable walls, with the substrates affixed to the inner surface of the removable walls. In an embodiment, the process chamber comprises automation capability to automatically transfer substrates to and from the fabrication facility. A robot can pick up the substrates from a previous processing station and bring substrates to the present processing chamber for single-sided wet processing. After process completion, the robot can pick up the substrates and deliver substrates to the next processing station.

In an embodiment, the present system comprises liquid supply and/or drainage. The liquid supply can be located at the bottom of the chamber, delivering chemical liquid to the process chamber through a liquid pump. The liquid supply can be located at the top of the chamber, delivering chemical liquid to the process chamber through gravity. The liquid supply can also be located at both top and bottom. Similarly, drainage can be located at the top and/or at the bottom, draining the liquid by gravity or by pumping.

The liquid supply can have a fast fill mode and a slow fill mode. For example, in a slow fill mode, liquid can be pumped upward from the bottom, with the flow rate controlled by the pumping speed. In a fast mode, the liquid can be supplied from the top, driven by gravity through large opening for fast chamber filling.

The liquid drainage can also have a fast drain mode and a slow drain mode. For example, in a slow drain mode, the liquid can be drained through the supply line, for example, by stopping the pumping action and letting the liquid flowing downward by gravity. Alternatively, the liquid can be pumped out in a controlled rate. In a fast mode, a separate drain port can be opened, and the liquid can be quickly drained to a reservoir.

Additional features can also be included, for example, a volume limiter within the process channel to further reduce the process volume, a stirrer, such as mechanical stirrer or ultrasonic or megasonic vibration, to mix the liquid in the process volume, heater for heating the liquid, cooling device for cooling the liquid, supply and drain reservoirs for holding chemical, etc.

Detailed description of the preferred embodiments The present invention discloses apparatuses and methods for wet processing of only one side of substrates, which, in certain situations, offers advantages over conventional wet processing of immersion or dipping of both sides of the substrates. The present single-sided wet process can be used for the etching of materials, or deposition of coatings and films on semiconductor substrates, glass substrates, metal plates and foils, plastic or polymer substrates, plates and foils and photovoltaic cells, antireflcctive coatings, antibacterial coatings, transparent conductive oxides, hydrophobic and hydrophilic coatings, anti corrosive coatings, nanocoalings, colorizing, SolGel processes, thin film photovoltaic buffer layers as well as other processes that are typical wet processes, such as electroplating and electroless deposition.

In an embodiment, the present invention provides wet coating to a single side of a substrate by maintaining the substrate as an integral part of the processing chamber wall, thereby preventing the coating fluid from coming into contact with the back surface not requiring the coating. The substrate is preferably disposed in a vertical or near vertical orientation.

In an embodiment, the present invention discloses a process chamber having a narrow channel of chemical liquid oriented in an upright direction, with the chemical liquid supplied from one or more short sides of the channel and the substrates facing one or more elongated sides of the channel. For example, the process chamber can have a narrow gap between two large opposite sides, which are large enough to accommodate the substrate surfaces.

Figs. 1 A and I B illustrate an exemplary process chamber according to an embodiment of the present invention. The process chamber 10 is positioned in an upright orientation, comprising two large opposite sides 1 1 at front and back, which is large enough to hold substrates 12, or at least, large enough to process a desired portion of the substrate surfaces. The two opposite sides 11 are joined by two narrow slats 17 at left and right, forming a narrow gap 13, which can be filled with chemical liquid to process the substrates 12. In an embodiment, the narrow gap is less than 12 mm, for example, between 2 mm and 12 mm wide, as compared to the large opposite sides of 300 mm by 300 mm or larger (such as 1000 mm by 1000 mm). The top and/or bottom of the process chamber 10 can be closed or open, with connection to chemical supply or drainage. The chamber volume 16 within the narrow gap forms a narrow channel configuration, which can be filled and drained of chemical liquid for processing the substrate 12 surfaces attached to the large opposite sides. The narrow channel configuration provides small processing volume for up to two substrates at two opposite sides, and thus offers significant advantages for minimizing the consumption of chemical and/or

rinsing/cleaning solutions. For example, the small chemical consumption can allow single use of chemical solutions, eliminating any process variations caused by chemical aging.

The substrates 12 can be disposed on one side or on both sides of the channel volume. For substrates disposed on both sides, the processing throughput can be doubled. For substrates disposed on one side, the other side can be used for adding wet process capability, such as heater to heat or cooling device to cool the chemical or the substrates, or stirrer (mechanical or ultrasonic or megasonic) to stir the chemical. In addition, multiple substrates can be disposed on one side of the channel volume.

The process chamber 10 further comprises a chemical supply mechanism 14 positioned at one end of the channel volume to provide chemical liquid to the narrow channel volume for processing, e.g., coating, the substrates. As shown, the supply mechanism 14 is disposed at the bottom of the process chamber, where the chemical can be pushed upward 15 toward the channel volume. Alternatively, the supply mechanism 14 can be disposed at the top of the process chamber, where the chemical can flow downward, for example, by gravity, to fill the channel volume. One or more chemical reservoirs can be included to provide chemical to the supply mechanism 14. Multiple supply mechanisms 14 can also be provided, at the top and/or bottom of the process chamber, for example, to offer different modes of filling the chamber.

In an embodiment, the chemical liquid can be drained back through the chemical supply mechanism 14, for example, by gravity if the supply 14 is at the bottom, or by aspiration or pumping if the supply is at the top. For example, a chemical reservoir can allow the chemical to fill the process channel, and then to drain the chemical in the process channel back to the reservoir. Alternatively, or additionally, one or more chemical drain mechanisms can be included, at the top, bottom or both top and bottom of the process chamber. The drain mechanism can be connected to a chemical storage for storing the chemical. Slow drain and fast drain modes can be included.

As shown, the process chamber 10 is positioned upright or vertically, e.g., disposed perpendicular or near perpendicular to the floor. Such vertical configuration of the process chamber allows small footprint for the process equipment, a desired characteristic for the semiconductor or solar cell production environment. Additional components can also be included. Temperature control devices can be added to control the chemical liquid or the substrates. For example, a heater/cooler can be added to heat/cool the chemical liquid. A second heater/cooler can be added to heat/cool the substrates. A controller can be used to regulate the temperature. Vibration mechanism such as mechanical stirrer or ultrasonic or megasonic, can be provided to the liquid. Operation valves and flow meters can be added to control the flow and the drain of chemical. A computer-controlled system may also be provided, for example, to allow a user to program the rates at which the processed mixture should be introduced and drained. In addition, the computer-controlled system can also control the amount of chemical mixture provided to the process chamber, and to program dwell times of the substrates in the process chamber.

In an embodiment, the substrates are placed in a carrier which is then attached to the sides of the process chamber. The process chamber is empty at this time, e.g., the liquid is drained from the process volume. There can be seal mechanisms at the substrates or at the carrier to seal the sides of the process chamber to prevent liquid leakage when the process volume is filled with a chemical solution.

The liquid supply mechanism then starts to fill the process volume with chemical liquid. The filling process can start from the bottom and rise to the top, or can start at the top and flow downward toward the bottom. The filling process can be slow filling, fast filling, or controlled filling, depending on the desired process conditions. The filling speed (e.g., volume speed or surface linear speed) can be adjustable, for example, by a recipe parameter, and depends on specific coating conditions, and can be different for different coating recipes and substrates. The linear draining speed, e.g., the speed of the liquid surface, can be in a speed range of 2 - 13mm/sec, or in a range of 0.2 - 30mm/sec,

After substrate process completion, for example, by completely filling the process volume, by achieving a desired coating thickness on the substrates or after a

predetermined time, the chemical liquid is then drained in a fast drain, slow drain, or in a controlled manner either by gravity, by a pump, aspirator, or by other means. The draining speed (e.g., volume speed or surface linear speed) is adjustable, for example, by a recipe parameter, and depends on specific coating conditions, and can be different for different coating recipes and substrates. The linear draining speed, e.g., the speed of the liquid surface, can be in a speed range of 2 - 13ram/sec, or in a range of 0.2 - 30mm/sec, or the chamber can be completely emptied within 2 seconds or greater,

In an embodiment, the process chamber is vibration-isolated from the other portions of the equipment, to prevent any transfer of vibration movement to the liquid bath.

The processed chemicals can be disposed, or can be reused for subsequent substrates, with or without adding refreshing chemicals. For example, the chemicals can be drained to a storage tank nearby. Alternatively, the chemicals can be returned to the chemical supply to use for the next substrates. Optionally, the chemicals can be processed to improve coating characteristics, such as by filtering or refreshing.

After draining the chemical liquid, the carrier is removed from the process chamber, and the substrates are removed from the carrier. Next substrates are then placed on the carrier, and the processing cycle re-starts.

Fig. 2 illustrates an exemplary flowchart for an exemplary single-sided wet process according to an embodiment of the present invention. In operation 20, one or more substrates are attached vertically to one or more opposite sides of a process chamber. In operation 22, chemical liquid is supplied to a narrow channel volume between the two opposite sides, exposing the surfaces of the substrates to the chemical liquid. In operation 24, the chemical is drained. In operation 26, the substrates are removed from the process chamber. The process can be repeated for next substrates.

In an embodiment, the channel volume is disposed upright or vertically, with the narrow channel running from top to bottom and the substrates positioned on the left and right. One of the advantages of vertically oriented channel volume is the small footprint of the process system, regardless of the sizes of the substrates. The vertical orientation is well suited for large substrates, such as glass panels used in display devices or in solar panels, since the footprint is constrained by the channel width between two opposite sides of the channel volume, and is independent of the substrate size. In addition, the vertical orientation of the channel volume can allow gravity-assist liquid supply or liquid drainage. For example, with a liquid supply mechanism located on the top of the channel volume, the chemical filling of the process volume can be accomplished by opening a valve connecting the liquid supply to the channel volume. Also, with a liquid drainage located on the bottom of the channel volume, the drain of the chemical in the process volume can be accomplished by opening a valve connecting the channel volume to the drainage. Also, the vertical orientation can offer fast supply or fast drainage of liquid chemical, for example, by fully opening connectional valves, allowing the chemical liquid to quickly fill to or drain from the channel volume. Further, the vertical orientation can reduce the trapping of bubbles at the substrate surfaces, allowing the bubbles to rapidly rise to the liquid surface with minimum resistance.

In an embodiment, the vertical orientation of the channel volume includes a perpendicular or near perpendicular orientation of the channel volume with respect to the floor. For example, the near perpendicular orientation comprises an angle less than 10 or 15 degrees with the vertical. In an embodiment, higher angles for the channel volume, for example, more than 15 degrees or more than 45 degrees, can be used at the expense of larger footprint.

In an embodiment, the small channel volume allows minimum consumption of chemical liquid. Further, the narrow channel configuration also allows for substrate scaling, e.g., enlarging systems to accommodate larger substrates, with the same ratio of chemical consumption. In addition, fluid volume reducers or displacers can be incorporated to the channel volume to further reduce the consumed chemical volume. The distance between substrate surfaces can be further optimized with improved technology, thus it is expected that further significant reductions of chemical consumables can be made, especially in comparison ith conventional immersion type processes.

In an embodiment, an advantage of the present small channel volume is the ability to minimize the volume of the chemical fluid needed to process, e.g., coat, the surface of the substrates. The small volume of the required chemical is directly related to the cost effectiveness of the wet process, by reducing the consumption of expensive chemical solutions. For example, in many cases, the chemical is single-use, meaning that the chemical is discarded after one coating process.

In an embodiment, the present process chamber allows processing of two substrates at the same time, by incorporating two substrates to both sides of the channel volume. This configuration doubles the throughput of the process chamber, with minimum overhead due to the loading of two substrates. Further, an advantage of the double substrate processing is the reduction of the active components in the chemical solution, especially for a coating process occurring due to the small area of the remaining chamber walls as compared to the area of the substrates. Thus the present invention provides conditions for an economic use of chemical consumables. For example, in a wet coating process, the chemical will coat any surfaces in contact with the chemical fluid, depleting the active components of the chemical. Most of the internal surface area of the present process chamber is formed by the substrate surfaces, for example, the two large opposite surfaces of the channel volume. Thus the present process chamber comprises minimal wasted internal surface area, e.g., the internal surface area not containing the substrate surfaces, the chemical will be depleted more slowly. Slower depletion action of the chemical will prolong the life of the chemical, requiring a less frequent addition of refreshin chemical. Alternatively, slower depletion action of the chemical would require lower concentration of active components, leading to a more dilute chemical usage.

In an embodiment, the process chamber comprises two large opposite sides to accommodate the substrates. For example, a large opposite side can comprise a flat area large enough to hold a flat panel, such as a glass flat panel display or a flat solar panel. A size of the large opposite sides can be about 0.3 m, 1 m, 2 m, or larger. In an

embodiment, the process chamber is positioned upright, with the opposite sides disposed on right/left or front/back. This configuration can accommodate different sizes of the flat panel with minimum increase in footprint. Other types of substrates can also be used, such as semi-rigid or flexible substrates, or multiple substrates mounting on one opposite side. Further, other configurations of the opposite sides can be used, such as curved surfaces.

Fig. 3 illustrates an exemplary process chamber according to an embodiment of the present invention. The process chamber 30 comprises two large opposite sides 31 on the left and right (only one side facing the right side is shown), joined by two narrow slats 37 on the front and back (only one slat facing the front is shown). The slats 37 are shown to be flat, but other configurations can be used, such as a curved portion joining the two left and right opposite sides. The particular orientation of left/right and front/back is only exemplary, included to clarify the system configuration. Other configurations can be used.

The top of the chamber can be open, or have a lid to prevent the escape of chemical vapor. Alternatively, the top can be closed, with a vent leading to an exhaust. The top of the chamber can be configured, e.g., tapered off, to accept chemical supply and/or drainage mechanisms, which can supply/drain fluid in the chamber volume. Similarly, the bottom of the chamber can be configured to accept chemical supply and/or drainage mechanisms 39.

The process chamber 30 is shown to be oriented vertically or near vertically, comprising an opening 32 on an opposite side 31 having a seal mechanism 33 to accommodate a substrate forming a chamber wall. Alternatively, the process chamber 30 can be described as comprising a removable wall on the opposite side 31. The removable wall is removed from the side 31, forming opening 32. The removable wall can support a substrate, together with mating seal mechanism 33 to seal the process volume when the removable wall is reattached to the side 31. The substrates can be attached to the removable wall by vacuum suction, or by other means of holding the substrate.

Figs. 4A - 4B illustrate an exemplary face seal for a process chamber according to an embodiment of the present invention. In an embodiment, the opposite side 31 comprises an opening 32 in the chamber wall, together with a seal, a seal surface, or other type of seal 33 surrounding the opening 32. As shown, the seal 33 is a face seal for the opening 32. Other types of seal mechanisms can also be used, such as an edge seal, sealing the inner edge of the opening 32. A substrate 34A, held by a support 35, can be mated to the seal 33, sealing the opening 32 of the process chamber. Thus when the process chamber is filled with chemical solutions, the substrate forms a wall for the chemical volume, exposing a single side of the substrate to the chemical to be processed, e.g. coating. Alternatively, the seal 33 is mated by a support 36, which supports one or more substrates 34B. The back and edge of the substrates 34B can be protected by the seal 33A in the support 36 to prevent coating at these areas.

Figs. 5A - 5B illustrate an exemplary edge seal for a process chamber according to an embodiment of the present invention. In an embodiment, opening 32 comprises an edge seal 33B to seal a substrate 34C, forming a wall portion of the side 31. The substrate 34C is supported by a substrate holder 35. Alternatively, the opening 32 comprises an edge seal 33D for mating with a support 36A. Substrate 34B is mounted on the support 36A, including optional edge seal 33A to protect the edge and the back sides of the substrate 34B. Edge seal 33 A can also protect a portion of the front area. Alternatively, in certain situations, edge protection is not needed, and thus the seal 33A only protects the backside.

In an embodiment, the supports 35, 36, and 36A can comprise an embedded temperature device 235, such as a heater for heating the substrate, or a cooler for cooling the substrate. The temperature device 235 is optional, serving as a means for setting the temperature of the substrate. A temperature controller (not shown) can also be included to regulate the temperature of the temperature device and/or the temperature of the substrate.

In an embodiment, the present system comprises automation for automatic processing of substrates. For example, the system comprises an input station, accepting multiple substrates, and then transferring individual substrates to the substrate support. After processing, the substrates are transferred to an output station.

In an embodiment, liquid supply and/or drainage are incorporated to the process chamber to provide chemical liquid to the process channel. In a preferred embodiment, the process chamber is disposed upright with the liquid supply and drainage disposed at the bottom and/or the top of the process channel.

Fig. 6Λ illustrates an exemplary supply and optional drainage disposed at a bottom of the process chamber. The process volume 60 is disposed upright with the opposite sides formed by substrates 65A and 65B. A flow controller 66 is disposed at the bottom of the process v lume 60, connecting the process volume 60 with a liquid supply 61 through a pump 62. The pump 62 is designed to push the liquid upward to the process volume 60. The flow controller serves to control the rate of chamber fill. For drainage, the liquid can be retracted back to the liquid supply 61 , for example, by stopping the pump and allowing the liquid to drain out of the process volume by gravity action. A bypass valve can be included to separately control the rate of drainage.

Fig. 6B illustrates an exemplary supply and drainage disposed at the bottom of the process chamber. A manifold 64 is disposed at the bottom of the process volume 60, allowing the process volume 60 to communicate with either a liquid supply 61 or a drainage 63. When manifold 64 connects the chamber volume 60 to the liquid supply 61 , a pump 62 can deliver the liquid upward to the process volume 60. Additional flow controller (not shown) can be included to control the rate of chamber filling. The chamber volume can be drained back to the liquid supply 61 by stopping the pump 62, and allowing the liquid to be driven out of the process volume by gravity back to the liquid supply 61.

Alternatively, the liquid can be drained through the drain 63. When manifold 64 connects the chamber volume 60 to the liquid drain 63, the liquid in the process volume

60 can be drained from the process volume 60, for example, to a container (not shown). Additional flow controller 69 can be included to control the rate of chamber drainage. The drainage 63 can allow fast drain of the process volume by fully opening the drainage flow controller 69. The drainage 63 is typically empty, and thus provides a faster drain flow than the drain through the supply 61.

Fig. 6C illustrates an exemplary supply and drainage disposed at a bottom of the process chamber together with a supply disposed at the top of the process chamber. A mani old 64 is disposed at the bottom of the process volume 60, allo ing the process volume 60 to communicate with either a liquid supply 6 through pump 62 or a drainage 63. In addition, at the top of the process volume 60, an additional supply 68 is connected to the process volume 60 through a valve mechanism 67.

The supplies 61 and 68 can be connected to provide a closed loop of liquid supply. For example, liquid supply is pumped by pump 62 from a reservoir (not shown) to supply

61 to process volume 60 to supply 68 and back to the reservoir. Supply flow can be reversed, e.g., flowing from supply 68 to process volume 60 to supply 61. In addition, fast fill mode can be provided by using gravity-assist filling, letting the liquid to fill the process volume through the supply 68.

Other configurations for supply and drainage of chemical liquid can be used, for example, a close-loop of liquid pumping and draining for the process volume, or a drainage at a top portion of the process volume, draining the liquid in the process volume by pumping or by aspiration. Figs. 7 A and 7B illustrate an exemplary system and sequence of loading substrates according to an embodiment of the present invention. The substrates 101 A and 10 I B are first prepared for processing by attaching them in a vertical {or near vertical) orientation to an external carrier or processing frame 1 5 A and 105B. An integrated vacuum plate within the process frame supports the substrate by vacuum contact to the back side of the substrate. The substrates 101 A and I 01B arc then ready to be loaded to the process chamber 102. To prevent contamination, the front side of the substrate (e.g., the surface of the substrate to be processed) is not to be touched before, during or after the wet processing step by any handling system. The use of back side vacuum handling can eliminate front side contamination, thus ensuring high process performance and repeatability. Temperature devices 235A/235B are optionally incorporated to the carriers or frames 105A/105B to set a desired temperature for the substrates 101A/101 B. For example, heaters can be used for heating and coolers can be used for cooling the substrates. In the present description, a temperature device can include a controller (integrated with the temperature device or connected externally at a separate location) to regulate the temperature.

The system 100 comprises a process chamber 102 with removable walls or openings to accommodate substrates 101 A and 101B. The bottom of the process chamber 102 is connected to a chemical supply mechanism 104 to carry chemical to the process volume 102. In the supply path, a temperature device 105 is optionally attached to a pipe wall to regulate the temperature of the liquid chemical. The temperature device is disposed in an enclosure with easy access, to prevent accidental exposure and to permit ease of servicing. The temperature device 105 can include a heater for heating the liquid chemical, or a coolin device can be used to cool the liquid chemical to a desired temperature. In the vicinity of the liquid supply, there is a fast drain line 106 with drain valve 107. During the supply of liquid, or during the drainage of the liquid supply, the drain valve is closed and the fast drain line is not accessible.

A container 1 10 is disposed at the top of the process chamber 102 for receiving the liquid supply after reaching the process chamber 102. An overflow mechanism 1 1 1 sets a limit of liquid in the container 1 10. When the liquid level exceeds the overflow setting, the liquid is removed by the overflow mechanism 1 1 1 , for example, to return to the liquid supply 104. The container 1 10 also includes a fast fill valve 1 12, actuated by a valve actuator 1 13. The fast fill valve 1 12 can stop the liquid flow to the container 1 10, and can allow the liquid in the container 1 10 to quickly fill the chamber volume 102. A vent mechanism 1 14 is included, for example, to allow the draining of the chamber volume when the fast fill valve is closed.

As shown, the substrates 101A and 101 B are attached to carrier 115A and 1 15B, respectively, through vacuum plate. However, other holding mechanisms can also be used, such as hooks or clamps.

After loading the substrates to the process frames, the whole assemblies, e.g., the frames with the attached substrates are then loaded to the processing chamber. One or two process frames can be used, and it is preferable that two (2) process frames will be attached to one process chamber at two opposite sides to provide a complete enclosed chamber environment. The gap between the substrate surfaces is preferably narrow (typically 2 - 12mm, or less than 20 or 50mm) in order to limit the volume of the required coating fluid.

Fig. 7B shows a system 100 with the substrates 101 A and lO IB loaded to the process chamber 102, ready to be processed. As shown, the substrates 101 A and 101 B are face sealed 120 to the process chamber 102. The carriers 1 15A and 1 15B support the substrates by vacuum suction, and are locked securely into position within the processing chamber by an integral clamping mechanism 121. The process chamber includes a flexible seal 120 around the entire periphery of the substrates forming internal surface walls of the process chamber. Minimum face seal 120 between the substrates and the process chamber is desirable, to have maximum coating surfaces on the substrates.

Fig. 8 illustrates an exemplary system with a reduced process volume according to an embodiment of the present invention. A fluid displacer 130 is placed in the process chamber to reduce the volume of the process chamber. In an embodiment, the fluid displacer 130 can also comprise a temperature device, such as a heater or a cooling mechanism to heat or cool or regulate the temperature of the chemical liquid in the process chamber. The system can comprise an optional temperature device 105 in the liquid delivery line to heat, cool or regulate the temperature of the chemical liquid in the delivery line and when the liquid passes through the delivery line. The system can further comprise optional substrate temperature devices 235A/235B to heat, cool or regulate the temperature f the substrates.

In an embodiment, the present invention discloses various configurations for the temperature devices 130, 105 and 235A/235B. For example, an exemplary process system can comprise only temperature devices 235A/235B for controlling the temperature of the substrates. A process system can comprise only temperature devices 130, only temperature device 105, or a combination of temperature devices 130 and 105 for controlling the temperature of the chemical liquid. A process system can also comprise any combination of these temperature devices, for example, temperature devices 235 A/235B for controlling the temperature of the substrates and temperature device 130 for controlling the temperature of the chemical liquid.

The present invention further discloses various settings for the temperature devices 130, 105 and 235Λ/235Β. The configurations of the temperature devices and their temperature settings are designed according to the processes and liquid chemicals.

In an embodiment, the present invention discloses a heated reaction process where the liquid chemical reacts with the substrates (e.g., deposition, coating, cleaning, etching, etc.) at temperatures higher than room temperature. In many processes, the high temperature is needed to activate or to accelerate the reaction. The liquid chemical can be heated through the temperature device 1 5, the temperature device 130, or a combination of these temperature devices. The substrates can be heated through the temperature devices 235A/235B. Also, a combination of temperature devices 105, 130 and

235A/235B can be used to optimize the heated reaction between the liquid chemical and the substrates. For example, the liquid chemical can be preheated by the temperature device 105, and reach a reaction temperature by the temperature device 130 or by the temperature device 235 A/235B. In an embodiment, the process chamber only comprises required temperature devices, for example, only the substrate heaters 235 A/235B, the substrate heaters 235A/235B together with liquid heater 105, the substrate heaters 235Λ/235Β together with liquid heater 130, the liquid heaters 130 and the 105, etc. Also, the temperatures for different heaters can be the same or different.

In an embodiment, the present invention discloses a cooling reaction process where the liquid chemical reacts with the substrates (e.g., deposition, coating, cleaning, etching, etc.) at temperatures lower than room temperature. In some processes, the low temperature is used for the reaction at the substrates, and thus the liquid chemical and/or the substrates are maintained at a low temperature through the temperature devices 105, 130, and/or 235A/235B.

In an embodiment, the present invention discloses a heated reaction process where the liquid chemical reacts with the substrates at temperatures higher than room temperature while the liquid chemical is kept at temperatures lower than room temperature. This configuration allows a high reaction temperature zone at the substrates to promote or to accelerate the reaction. In addition, this configuration provides a low temperature zone for liquid chemical to preserve the chemical properties, allowing re-usage or long term storage of the liquid chemical. Thus the liquid chemical is maintained at a high temperature in the vicinity of the substrates and maintained at a lower temperature away from the substrates and at the deliver)' line. For example, the temperature devices 130 and 105 comprise cooling mechanism to provide a cooler environment for the liquid chemical as compared to the vicinity of the substrates. The temperatures of the temperature devices 130 and 105 can be the same or can be different, to achieve an optimization of liquid chemical processing. The substrate environment is maintained at a higher temperature, for example, by keeping the substrates at room temperature or by heating the substrates to a desired temperature, through the temperature device 235A/235B.

In an embodiment, the temperature devices 235A/235B for the substrates are heaters to heat the substrates, and the temperature devices 130 and optional temperature device 105 (or the temperature devices 105 and optional temperature device 130) comprise cooling mechanisms to cool the liquid chemical.

This function provides a means to permit the recycle of certain chemicals or chemical mixes that exhibit a tendency to flocculate or agglomerate with increases in temperature, for example, but not limited to, mixtures of Ammonium Hydroxide, ThioUrea and Cadmium or Zinc Salts. For example, certain chemical deposition is known to occur when the chemical reaches a certain temperature at the deposition interface. However, long term exposure to this temperature will result in agglomeration and flocculation into larger clusters, rendering the liquid chemical to be no longer useful and to be discarded. In an embodiment, the present invention discloses the creation of conditions for the deposition at the substrate surfaces by directly heating the substrates and preserving the chemical solution, by reducing the temperature in solution, for example, by preventing agglomeration or flocculation. Thus, the substrates are heated by temperature devices 235Λ/235Β, and the liquid chemical is cooled by applying cooling to the displacer 130, externally in the recirculation line 105, or to both temperature devices 130 and 105. The temperature devices 130 and 105 are designed to prevent or limit the chemical solution, for example, the liquid not within close proximity to the substrate surface, from entering the flocculating phase. In an embodiment, additional cooling stages can be added, for example, at the exit line of the chemical liquid from the process chamber. A series of filtration steps can also be included, for example, to remove any agglomeration or flocculation, before allowing the chemical solution to be reused.

In an embodiment, the present invention discloses a process to wet process single- sided substrates using vertical narrow channel configuration. Figs. 9A and 9B illustrate an exemplary sequence of filling the process chamber according to an embodiment of the present invention. The substrates are attached to the walls of the process volume, and optionally are regulated to a desired temperature, for example, through embedded temperature devices. Then the chemical liquid can start filling the process volume. Drain valve 107 is closed, and the chemical supply 1 4 is on, pumping liquid to the process chamber. Depending on the process conditions, e.g., the requirement of the temperature of the chemical solution, temperature device 105 or 130, such as a heater (or a cooling mechanism) can be turned on to heat (or to cool) the liquid. As shown in Fig. 9A, coating chemical is supplied via a pump through the chemical sup ly inlet 104 through a diffuser chamber to ensure an even distribution of the chemical within the chamber. The chemical then passes over an optional heater/cooler plate 105 and into the process chamber 102. The chemical then fills the processing chamber covering the exposed substrate surfaces.

After filling the process chamber, for example, flowing to completely cover the substrates, the flow can stop and the active chemicals in the solution to react with the walls, e.g., the substrate surfaces, to process the substrates. Alternatively, the chemical supply can continue to flow upward to the container 1 10 as shown in Fig. 9B. As the chemical passes over the substrates it enters an upper collection tank 1 10 where it can be stored or recycled to the chemical supply 104 (via the overflow) for recirculation back to the processing chamber.

In an embodiment, the process system further comprises a feature for rapid emptying and refilling, which can be beneficial for some chemical processes. For example, to facilitate rapid emptying, the fast fill valve 1 12 is closed and the fast empty drain valve 107 is opened.

Figs. 10A and 10B illustrate an exemplary fast drain operation according to an embodiment of the present invention. When the process is completed, the liquid can be drained from the process chamber before the substrates can be removed. In certain cases, a rapid drain of the liquid from the process chamber can be performed by stopping the chemical supply, e.g., closing the chemical supply 104 and shut down fast fill valve 112, and then by opening the fast drain valve 107 (Fig. 10A). At this point chemical within the process chamber is quickly drained and stored for reuse or discarded. The fast drain operation can be accomplished since valve 107 offers full opening of drainage, together with empty drain line to a container. In addition, chamber volume is limited by valve 1 12, providing only minimum liquid volume to be drained. The drain action stops when the liquid level is below the drain valve 107 (Fig. 10B).

Alternatively, there are some applications where slow draining of the fluid is desirable. In these applications, the fast drain function may be replaced by a regulated draining valve to provide a constant regulated draining speed.

Fig. 1 1 illustrates an exemplary fast fill operation according to an embodiment of the present invention. To rapidly fill the chamber the fast empty drain valve 107 is closed and the fast fill valve 1 12 opened to release the stored chemical in the collecting tank which rapidly refills the process chamber by gravity. The chemical supply 104 can be turned on to further pumping the liquid to the process chamber. The chemical supply 104 pumps the liquid level upward, in addition to the liquid flowing down from the container 1 10, providing a fast filling action for the process chamber.

Additional components can be included to the process system, such as a heater/cooler to heat/cool the chemical liquid. The heater/cooler can be disposed at the liquid supply portion, in the liquid stream or at the wall of the liquid supply, to heat/cool the liquid before reaching the process volume. The heater/cooler can be disposed in the process volume, to heat/cool the liquid directly near the substrate areas. Other temperature devices can be included to control the temperature of the substrates, for example, a heater embedded in the substrate support, heating the substrates at the back side, e.g., the side not to be wet processed. The substrate holder vacuum plates may be heated, directly by attached heating elements or indirectly e.g. by heating fluid or gas passing through channels which will be incorporated into the vacuum plates. As temperature will typically increase the speed of the chemical reaction a heated surface will shorten the process times. Alternatively, for certain chemicals, low temperatures might be desirable, for example, to preserve the chemical lifetime, or to control the chemical reaction. The temperature, hot or cold, of the substrates should be uniform to achieve a uniform coating.

A heating/cooling cycle can be incorporated to pre-heat/pre-cool the substrate and chamber prior to introduction of the processing liquid by first filling with water and circulating the water over the heaters/coolers thereby heating/cooling the internal components before the introduction of the processing fluid.

There can be other components, such as stirrer (mechanical or ultrasonic) to stir the liquid, flow disrupter to limit the volume or to create turbulence in the process volume, liquid spray or nozzles to clean the process volume or the substrates, air bubble mechanism to aerating the chemical solutions, bubble formation and collapse to aid in chemical reaction, etc.

For example, a rinsing process may be required, depending on the chemical coating fluid, to rinse the coated surface with a rinsing agent (such as ultrapure water). Thus, in an embodiment, rinsing capability such as rinsing medium flow from bottom to top or from top to bottom of the process chamber or spraying nozzles may be integrated to the process chamber.

Further, a drying process to dry the substrate surface may be required. Thus, in an embodiment, optional air, inactive gas or inert gas (such as nitrogen) flow can be directed into the processing chamber. This drying agent may operate at ambient temperature or heated by heating elements integrated into the dryin gas supply line. In an embodiment, a chamber cleaning mechanism can be included to clean the process chamber. Since the chemical supply also coats the process chamber walls, a cleaning fluid can be introduced to periodically remove the chamber wall coating films. Thus a separate cleaning media with supply line can be integrated to distribute the cleaning agent over the surfaces of the chamber walls.

In an embodiment, the system comprises multiple chemical inlets for introducing multiple chemical solutions. The system can further comprise integrated chemical mixing capability of the introduced chemical supplies. Certain coating processes might require mixing of different chemicals. In some cases the chemicals start to react immediately after mixing. For such cases, the present integrated mixing can prepare the mixing solution in close proximity to the process chamber.

The present process chamber can provide a uniform wet thin film coating to the substrates. In an embodiment, the chemical supply flow pattern and the highly symmetric design of the present process chamber provides ideal conditions for a laminar flow condition of the coating fluid and consequently excellent coating uniformity.

In an embodiment, the present system can feature several processing chambers permitting high volume production with significantly reduced overall footprint.

In an embodiment, the present invention discloses systems and methods for a wet process comprising a point of use liquid delivery. In many wet processes, a high temperature is required for promoting and accelerating the reaction of the liquid chemical with the substrates. However, the high temperature can degrade certain chemicals, such as by decomposition or formation of agglomeration. Thus, in an embodiment, the present invention discloses a point-of-use wet process where the liquid chemical is kept at a low temperature (e.g., lower than room temperature for preserving the chemical) and is exposed to high temperature (e.g., higher than room temperature for reaction) only at the vicinity of the substrate surfaces. Therefore, a high temperature reaction zone is established only at the substrate surface, with a high temperature gradient to the outside of this reaction zone, allowing a liquid chemical to be maintained at a low temperature and entering the reaction zone only for reacting. An exemplary system according to an embodiment of the present invention comprises a heater to heat a substrate and a cooling device disposed in a vicinity of the substrate and/or at a liquid flow path to actively reduce the temperature of the liquid chemical away from the heated substrate.

Figs. 2A-12C illustrate exemplary system configurations for a wet processing system according to an embodiment of the present invention. An exemplary system comprises one or more substrates having surfaces exposed to a liquid chemical. The system further comprises heaters to heat the substrates to a desired process temperature. Disposed close to the substrates are one or more cooling devices to regulate the liquid chemical at a desired storage temperature, which serves to prevent damage or degradation to the liquid chemical. The cooling devices are disposed in a vicinity of the substrates in order to minimize the exposure of the liquid chemical to a hot environment generated from the heater heating the substrates. Thus, in an embodiment, a minimum reaction environment near the substrates are maintained at a high temperature to promote the reaction with the substrate, and the temperature of the liquid chemical is sharply reduced to a lower temperature outside of this reaction environment through active cooling devices. In an embodiment, there is no restriction on the process chamber, and thus the process chamber can comprise a container within which the substrates are submerged, or the process chamber can comprise an opening for attaching a substrate, as shown in other configurations of the present description. In addition, the process chamber and the substrates can be constructed in various orientations, from vertical to substantially vertical, to horizontal.

Fig. 12A shows a bottom face-seal system for wet processing substrates, comprising an opening for mounting a substrate 121. The face-seal system can be constructed similar to other chamber configurations described previously. The substrate 121 is attached to a support 120, which comprises a heater 122. The heater 122 can be a resistive heater, designed to heat the substrate 121 by contact. Alternatively, other heaters can be used, such as infrared light heater or microwave heater. The substrate surface is exposed to a liquid chemical 123, which can react with the heated substrate 121 to promote a reaction, such as depositing a coating, cleaning, or etching the substrate 121. Away from the substrate 121 is a cooling device 127, designed to keep the liquid chemical 123 at a desired temperature, and/or providing a fast reduction of the temperature of the liquid chemical away from the heated substrate 121. In an embodiment, the cooling device 127 comprises a plate configuration, substantially covering a large area of the substrate 121 , thus effectively limiting the hot liquid environment to a region near the substrate surface.

The temperatures of the heater 122 and the cooling device 127 are designed to optimize the heated reaction zone in front of the substrate 121. In an embodiment, the temperature of the heater 122 is higher than the temperature of the cooling device 127. In an embodiment, the heater 122 is heated to a temperature between room temperature and about l OOC or 200C, and the cooling device is cooled to a temperature between room temperature and about -50C or - l OOC. In an embodiment, one of the heater 122 and the cooling device 127 can be maintained at room temperature.

The distance 129 between the substrate 121 and the cooling device 127 is preferably kept at a minimum, for example, less than 10 to 100 mm, to protect the liquid chemical from the reaction zone, and large enough to provide an adequate reaction zone for the substrate 121 , for example, to achieve a desired uniformity or throughput. Additional temperature devices can in incorporated, such as temperature device 128 disposed in a liquid delivery line, temperature device 126 disposed in a liquid reservoir 125. The temperature settings for these temperature devices can be the same or different, and can be heater or a cooling device. The system can comprise other components 124, such as pump, flow regulation, or filter devices.

Fig. 12B shows a system having side openings for mounting substrates, comprising substantially vertical side-by-side openings. Substrates 121 A and 12 IB are heated by heaters 122 A and 122B, respectively. A cooling device 137 is disposed in the liquid environment between the substrates 121 A and 12 IB, effectively limiting the heated reaction zones to the vicinity of the substrates. Additional temperature device 126 is disposed in a liquid delivery system 135 which delivers liquid to the process chamber. The additional temperature devices 126 can be a heater or a cooling device, depending on the process requirements.

Fig. 12C shows a similar system having side openings for mounting substrates. In this configuration, it might not be desirable to install a cooling device in the space between the substrates 121 A and 121B, for example, due to the narrow volume, or the requirement of a heated reaction zone in front of the substrates. Thus the cooling devices 138A and 138B are disposed outside, but close to the heated reaction zone to regulate the temperature of the liquid chemical. The top cooling device 138B allows for cooling the liquid chemical in an upward flow, and the bottom cooling device 138A allows liquid chemical cooling in a downward flow.

In an embodiment, the present invention discloses methods for wet processing substrates that can preserve the liquid chemical. In an embodiment, the liquid chemical is kept at a low temperature (e.g., lower than a reaction temperature, or a temperature that can degrade the chemical), and is brought to a high temperature reaction zone in the vicinity of the substrates for a reaction process. The reaction zone is limited to a volume surrounding the substrates, with a high temperature gradient at the boundary of the reaction zone to permit the temperature of the liquid chemical to quickly be reduced. In an embodiment, the substrate is exposed to a liquid chemical in a process chamber. The substrate is heated to a process temperature, generating a high temperature reaction zone in the region surrounding the substrate surfaces. A cooling device is then disposed at a location in the vicinity of the substrates, effectively establishing a boundary for the high temperature reaction zone with a high temperature gradient, allowing the liquid chemical to be kept at a high temperature only at the reaction zone, and maintained at a low temperature outside this immediate reaction zone. This process of limiting the high temperature exposure of the liquid chemical can prolong the lifetime of the chemical, preserving its reaction capability, preventing high temperature degradation of the chemical, and allowing recycling the chemical for reuse. In an embodiment, filtering and reconditioning (such as refreshing or adding make-up solution) of the chemical can be applied to improve the liquid chemical conditions.

Fig. 13 illustrates a flowchart of an exemplary process according to an embodiment of the present invention. In operation 140, a substrate is heated to a desired process temperature. The heating can be contact heating such as resistive heating, or contactless heating such as infrared heating. The substrate can be mounted to a support frame which comprises an embedded heater. In an embodiment, the substrate is attached to an opening in a process chamber, forming a wall. In operation 142, liquid chemical is provided to the substrate surface. For example, the liquid chemical can be introduced to the process chamber where the substrate (and the support) forms a chamber wall. Alternatively, the substrate can be disposed in a process chamber where the liquid chemical is introduced to submerge the substrate under the liquid. The sequence can be reversed so that the liquid is introduced to a process chamber before contact with the substrate.

After the substrate is exposed to the liquid chemical, the liquid chemical can react at the heated substrate. The reaction can be a deposition, an etch, or a cleaning process. The chemical can be stationary or circulated, for example, by looping flow between a reservoir and the substrate area.

In operation 144, the liquid chemical is actively cooled to a desired non-reactive temperature at a distance away from the substrate. The non-reactive temperature is lower than the process temperature, such as a temperature that prevents degradation of the chemical. The active cooling process can rapidly cool the chemical, establishing a high temperature gradient, limiting the heated process volume surrounding the substrate, and in general, reducing the potential damage, degradation or loss of active ingredients in the liquid chemical, and permitting re-usage of the chemical for subsequent substrate processing. The active cooling process can be performed by cooling devices, such as a cold plate, or a plate with low temperature fluid circulation.

In operation 146, the liquid chemical is optionally conditioned to restore or replenish its strength, or in general, making the chemical suitable for re-use, either with the current substrate or with subsequent substrates. For example, the chemical can be filtered to remove particulates or any agglomeration caused by the exposure to high temperature. The chemical can also be replenished, for example, by adding fresh chemical or regenerating the used chemical. After completing the substrate processing, the liquid chemical can be drained to a reservoir, ready to be re-used for subsequent processes [e.g. apple, strawberries]. The substrate is removed and new substrates can be brought in for a next cycle of process.

While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.

Claims

1. Method of single sided wet-processing of one or more substrates, comprising exposing only one side of the substrates to a liquid medium for processing, wherein the substrates are used for forming one or more walls of a process chamber of a processing system.

2. Method according to claim 1, characterized in that the substrates are oriented vertically or near vertically in the process chamber.

3. Method according to claims 1 or 2, characterized in that the liquid medium is introduced at the bottom or the top of the processing chamber.

4. Method according to any of the preceding claims, characterized in that the liquid medium is introduced into the process chamber from one or more short sides of the process chamber.

5. Method according to any of the preceding claims, characterized in that the speed of the liquid medium covering the substrates is controlled.

6. Method according to any of the preceding claims, characterized in that the process chamber comprises a liquid channel, wherein the substrates are provided at opposing sides of the liquid channel.

7. Method according to any of the preceding claims, characterized in that the liquid medium is filtered.

8. Method according to any of the preceding claims, characterized in that one or more

substrates are provided on a carrier, which may be attached to the process chamber.

9. Method according to any of the preceding claims, characterized in that the substrates are affixed to the process chamber and exposed to the liquid medium during in the process chamber.

10. Method according to any of the preceding claims, characterized in that the substrates are attached to removable walls, which are affixed to the process chamber during the wet process.

11. Method according to any of the preceding claims, characterized in that the removable walls or the substrates are sealed with the process chamber .

12. Method according to any of the preceding claims, characterized in that the substrates are automatically transferred to and from the process chamber.

13. Method according to any of the preceding claims, characterized in that the liquid medium is drained from the process chamber.

14. Method according to any of the preceding claims, characterized in that the liquid medium is stirred in the process chamber.

15. Method according to any of the preceding claims, characterized in that the temperature of the liquid medium and/or the substrates is controlled.

16. Method according to any of the preceding claims, characterized in that multiple substrates are disposed on one side of the chamber volume.

17. Method according to any of the preceding claims, characterized in that the process chamber is vibration isolated from other parts of the equipment.

18. Processing system for single sided wet processing of one or more substrates, comprising a process chamber to receive a liquid medium for processing of the substrates, wherein one or more walls of the processing chamber are formed by the substrates.

19. System according to claim 18, characterized in that the the substrates are oriented vertically or near vertically in the processing chamber.

20. System according to claim 18 or 19, characterized in that a pumping mechanism or a mass flow controller are provided in order to control the supply of the liquid medium to the processing chamber.

21. System according to any of the preceding claims 18 to 20, characterized in that the process chamber comprises a liquid channel, wherein the substrates are attached at both sides of the liquid channel.

22. System according to any of the preceding claims 18 to 21, characterized in that a carrier for one or more substrates is provided, which may be attached to the process chamber.

23. System according to any of the preceding claims 18 to 22, characterized in that the process chamber comprises removable walls with mating interfaces.

24. System according to claim 23, characterized in that the substrates are the removable walls, affixed to the process chamber to be exposed to the liquid medium during in the process chamber.

25. System according to claim 23, characterized in that the substrates are attached to the removable walls, which are affixed to the process chamber during the wet process.

26. System accoring to any of the preceding claims 23 to 25, characterized in that a sealing

mechanism between the removable walls or the substrates with the process chamber is provided .

27. System according to claim 26, characterized in that the sealing mechanism is a face seal or an edge seal.

28. System according to any of the preceding claims 18 to 27, characterized in that the system comprises automation capability in order to automatically transfer substrates to and from the process chamber.

29. System according to any of the preceding claims 18 to 28, characterized in that the system comprises liquid supply and/or drainage.

30. System according to any of the preceding claims 18 to 29, characterized in that a volume limiter or displacer is provided in the process chamber to reduce the process volume.

31. System according to any of the preceding claims 18 to 30, characterized in that a stirrer is provided in the process chamber.

32. System according to any of the preceding claims 18 to 31, characterized in that temperature control devices are provided to control the temperature of the liquid medium and/or the substrates.

33. System according to claim 32, characterized in that one or more heaters for heating the liquid medium and/or the substratesare provided.

34. System according to claim 32 or 33, characterized in that one or more cooling devices for cooling the liquid medium and/or the substrates are provided .

35. System according to any of the preceding claims 18 to 34, characterized in that multiple substrates are disposed on one side of the chamber volume.

36. System according to any of the preceding claims 18 to 35, characterized in that the process chamber is vibration isolated from other parts of the equipment.

37. System according to any of the preceding claims 18 to 36, characterized in that an overflow mechanism is provided for the process chamber.

38. System according to any of the preceding claims 18 to 37,characterized in that a process chamber cleaning mechanism is provided.

39. System according to any of the preceding claims 18 to 38, characterized in that several process chambers are provided.